TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Optical and Spectroscopic Properties of Glasses N2 - Optical glasses have given us the eyes to unveil the microscopic and the macroscopic worlds through microscope and telescope lenses, they have revolutionized the way we communicate through fiber optics and portable device screens, as well as given us new perspectives for sustainable energy harvesting conversion and generation. To meet the demands of ever-growing markets, the compositional design of new glasses requires full characterization of thermal, mechanical, electric, and optical properties. Particularly, the characterization of optical properties is not only relevant for optical/luminescent applications but is also essential for the tailored design of some medical and dental materials such as restorative resins, implants and prothesis. In this seminar we will introduce the fundaments on the optical properties of materials, with particular focus on glasses, and the techniques to characterize them. T2 - 3rd Sao Carlos School on Glasses and Glass-Ceramics CY - Sao Carlos, Brazil DA - 10.03.2025 KW - Optical properties KW - Glasses PY - 2025 AN - OPUS4-63773 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Structure and photophysics of RE ion doped gallium phosphofluoride glasses containing silver nanostructures: Effects of heat treatment and femtosecond direct laser writing. N2 - Gallium fluoride phosphate glasses are interesting hosts for emissive rare-earth (RE) dopants. Despite featuring low refractive index, they present high energy radiation resistance and a wide optical transmission range (350 to 1700 nm) enabling observation of important RE3+ emissions in the visible to near-infrared spectral range. In a previous, NMR-based structural study of the system xGa(PO3)3–(40-x)GaF3–20BaF2–20ZnF2–20SrF2 (x = 5 - 25 mol%), we verified that the network structure of these glasses is dominated by P-O-Ga linkages with no P-O-P linkages and that Ga is mainly six-coordinated in a mixed fluoride/phosphate environment. For Eu3+ doped samples, the photophysical properties strongly suggest changes in the ion´s ligand distribution toward a fluoride-dominated environment at low P/F, which translates into improved radiative emissions. To extend the studies to other RE doped glasses, and glasses containing Ag nanostructures (and their influence on RE emission), we selected the composition 25Ga(PO3)3 – 20ZnF2 – 30BaF2 - (25 – x - y)SrF2 – xAgNO3 - yNdF3, where x = 0, 1, 3, 5, 10 mol% and y = 0 or 1 mol%. The glasses were synthesized through the conventional melt-quenching technique and fully characterized from the thermal, structural, and microstructural viewpoints. By appropriate heat-treatment, the presence of both Ag nanoclusters (Ag-NCs, < 10 nm) and larger nanoparticles was confirmed by TEM in agreement with the observation of broad emission bands in the visible spectrum. Excited state lifetime measurements evidence the presence of non-radiative energy transfer processes between the Ag species to Nd3+ ions but there is no direct evidence of plasmon enhancement effects. In samples singly doped with silver, direct laser writing experiments using a femtosecond laser were also performed which induced localized growth of Ag-NCs associated to a variation in the refractive index. Preliminary results indicate the potential of the DLW technique for tailoring optical glass properties. T2 - 27th International Congress on Glass 2025 CY - Kolkata, India DA - 20.01.2025 KW - Gallium phosphofluoride glass KW - Structure-property correlation KW - Femtosecond direct laser writting KW - Neodymium PY - 2025 AN - OPUS4-63774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina T1 - Composition-structure-property relationships of ternary borate glasses N2 - Since the pioneer work of Krogh-Moe [1] in the 1960’s the structure clarification of borate glasses is of interest for many generations. In the present contribution the composition–structure–property relationships of Me2O–ZnO–B2O3, Me = Li (LZB), Na (NZB), K (KZB), Rb (RZB), CaO–ZnO–B2O3 (CaZB), and Li2O–PbO–B2O3 (LPbB) glasses are investigated. Non-toxic, highly polarizable zinc oxide potentially substitutes harmful lead oxide in glasses for applications e.g., in photovoltaics and microelectronics. Glass structure was analyzed using Raman and infrared spectroscopy, and the glass properties were measured using dilatometry (Tg, viscosity data, coefficient of thermal expansion) and rotational viscometry (high-temperature viscosity) [2,3]. The spectroscopic results show that alkali and calcium ions largely balance out the negative charges of BO4-units, while zinc and lead ions mainly stabilize the non-bridging oxygen atoms (NBO). The type of network modifier ion directs formation of the BO4-containing groups and the number of BO4-units (N4). Thus, i.) BO4-containing pentaborate was assigned in LZB, NZB and CaZB glasses, and ii.) diborate in KZB and RZB glasses. Simultaneous presence of pentaborate and diborate was only detected in LPbB. The combination of modifier’s properties, i.e., lower Lewis’s basicity (Rb+ > Li+), higher field strength (Rb+ < Li+), lower polarizability (Rb+ > Li+), and steric effects with increasing size (Rb+ > Li+) [4], leads to slightly increasing N4 in the series RZB (0.36) ≈ KZB < NZB (0.37) < LZB ≈ CaZB (0.39). This increase in N4 results in an increase in the atomic packing density 0.519 (RZB) – 0.584 (LZB) and thus in the Young’s Modulus 38.1 GPa (RZB) – 92.5 GPa (LZB) and in the glass transition temperature (Tg) 444 °C (RZB) – 467 °C (LZB) in the alkali series. In reverse order the coefficient of thermal expansion decreases from 12·10-6 K-1 (RZB) – 8.54·10-6 K-1 (LZB) with increasing N4. Ca2+ in CaZB enhances the viscosity (Tg: 580 °C) compared to Li+ in isocompositional LZB due to higher coordination. On the other hand, Pb2+ in LPbB decreases the viscosity (Tg: 399 °C) compared to Zn2+ in LZB with similar molar fractions. T2 - 98th Glass-Technology Conference of the German Society of Glass Technology (DGG) CY - Goslar, Germany DA - 26.05.2025 KW - Borate glasses KW - Structure-property relationship PY - 2025 AN - OPUS4-63771 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Xie, Zhuocheng A1 - Atila, Achraf A1 - Guénolé, Julien A1 - Korte-Kerzel, Sandra A1 - Al-Samman, Talal A1 - Kerzel, Ulrich T1 - Predicting grain boundary segregation in magnesium alloys: An atomistically informed machine learning approach N2 - Grain boundary (GB) segregation substantially influences the mechanical properties and performance of magnesium (Mg). Atomic-scale modeling, typically using ab-initio or semi-empirical approaches, has mainly focused on GB segregation at highly symmetric GBs in Mg alloys, often failing to capture the diversity of local atomic environments and segregation energies, resulting in inaccurate structure-property predictions. This study employs atomistic simulations and machine learning models to systematically investigate the segregation behavior of common solute elements in polycrystalline Mg at both 0 K and finite temperatures. The machine learning models accurately predict segregation thermodynamics by incorporating energetic and structural descriptors. We found that segregation energy and vibrational free energy follow skew-normal distributions, with hydrostatic stress, an indicator of excess free volume, emerging as an important factor influencing segregation tendency. The local atomic environment’s flexibility, quantified by flexibility volume, is also crucial in predicting GB segregation. Comparing the grain boundary solute concentrations calculated via the Langmuir-McLean isotherm with experimental data, we identified a pronounced segregation tendency for Nd, highlighting its potential for GB engineering in Mg alloys. This work demonstrates the powerful synergy of atomistic simulations and machine learning, paving the way for designing advanced lightweight Mg alloys with tailored properties. KW - Machine learning KW - Grain boundary segregation KW - Magnesium alloys KW - Atomistic simulation PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638499 DO - https://doi.org/10.1016/j.jma.2025.03.021 SN - 2213-9567 VL - 13 IS - 6 SP - 2636 EP - 2650 PB - Elsevier B.V. AN - OPUS4-63849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ruehle, Bastian T1 - Workflow generation, management, and semantic description for Self-Driving Labs N2 - The software backend that controls the robotic hardware and runs the synthesis workflows is a very important component of any Self-Driving Lab (SDL). On the one hand, it has to deal with orchestrating and managing complex and task-specific hardware through low-level communication protocols and plan and use the available resources as efficiently as possible while executing (parallelized) workflows, on the other hand, it is the interface the users use to communicate with this highly complex platform, and as such, it needs to be as helpful and user-friendly as possible. This includes the AI-aided experimental design in which the system helps the user to decide which experiment to run next, providing automated data analysis from characterization measurements, and offering easy to understand tools and graphical user interfaces for generating the workflows that are executed on the platform. Lastly, the specificity of the workflows and their dependence on the hardware and software of the SDLs necessitates a common description or ontology for making them easily interchangeable and interoperable between different platforms and labs. In this contribution, we present several key aspects of “Minerva-OS”, the central backend that orchestrates the syntheses workflows of our SDL for Nano- and Advanced Materials Syntheses [1]. One key feature is the resource management or “traffic control” for scheduling and executing parallel reactions in a multi-threaded environment. Another is the interface with data analysis algorithms from in-line, at-line, and off-line measurements. Here, we will give examples of how automatic image segmentation of electron microscopy images with the help of AI [2] can be used for reducing the “data analysis bottleneck” from an off-line measurement. We will also discuss, compare, and show benchmarks of various machine learning (ML) algorithms that are currently implemented in the backend and can be used for ML-guided, closed-loop material optimization in our SDL. Lastly, we will show our recent efforts [3] in making the workflow generation on SDLs more user-friendly by using large language models to generate executable workflows automatically from synthesis procedures given in natural language and user-friendly graphical user interfaces based on node editors that also allow for knowledge graph extraction from the workflows. In this context, we are currently also working on an ontology for representing the process steps of the workflows, which will greatly facilitate the semantic description and interoperability of workflows between different SDL hardware and software platforms. T2 - Accelerate 2025 CY - Toronto, Canada DA - 11.08.2025 KW - Nanomaterials KW - Advanced Materials KW - Workflows KW - Machine Learning KW - SDL PY - 2025 AN - OPUS4-63936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lemiasheuski, Anton A1 - Wehrkamp, F. A1 - Bajer, Evgenia A1 - Sonnenburg, Elke A1 - Göbel, Artur A1 - Porohovoj, Ilja A1 - Bettge, Dirk A1 - Pfennig, Anja T1 - Practical application of an automated 3D metallography system for the reconstruction and microstructural analysis of porosity in a sintered steel N2 - In the 3D microstructural analysis of a digital twin of porosity in the sintered steel Astaloy CrA, pore shape, average pore size as well as pore distribution will be analyzed. Porosity plays a major role in powder-metallurgical materials since it greatly impacts the mechanical properties of these materials and therefore represents a key parameter in their characterization. Based on the robot-assisted automated serial sectioning and imaging (RASI) system of the Federal Institute for Materials Research and Testing (BAM, Bundesanstalt für Materialforschung und Prüfung) in Berlin, the technique of metallographic serial sectioning will be used to image the microstructure and reconstruct a digital 3D twin from the stack of images obtained. Compared with an individual 2D microsection, the quantitative microstructural analysis of this 3D twin will enable more accurate conclusions on the shape, size and distribution of pores. This paper will detail the key steps in 3D microstructural analysis, including the metallographic preparation routine, the imaging technique, image alignment as well as the segmentation of pores. After the methodology has been described, the results of the quantitative microstructural analysis will be presented and the validity of quantitative parameters of 3D and 2D images will be compared and discussed. The analysis of more than 10,000 pores revealed a correlation between pore shape and pore size. It was also found that a 2D representation of the material surface is insufficient for a precise quantitative characterization of porosity. N2 - In der 3D-Gefügeanalyse eines digitalen Zwillings von Poren in einem Sinterstahl des Typs Astaloy CrA werden sowohl die Porenform als auch die durchschnittliche Porengröße und -verteilung analysiert. Die Porosität spielt in pulvermetallurgischen Werkstoffen eine große Rolle, da sie erheblich die mechanischen Eigenschaften beeinflusst und daher bei der Charakterisierung dieser Werkstoffe ein wichtiger Parameter ist. Basierend auf der Verwendung des Robot-Assisted Automated Serial-Sectioning and Imaging (RASI)-Systems der Bundesanstalt für Materialforschung und Prüfung (BAM) in Berlin, wird das metallographische Serienschnittverfahren genutzt, um das Gefüge aufzunehmen und aus dem Bildstapel einen digitalen 3D-Zwilling zu rekonstruieren. Verglichen zu einem 2D-Einzelschliff ermöglicht die quantitative Gefügeanalyse dieses 3D-Zwillings präzisere Aussagen zu Porenform, -größe und -verteilung. Diese Arbeit beschreibt die wesentlichen Schritte, die für eine 3D-Gefügeanalyse nötig sind, darunter die metallografische Präparationsroutine, das Bildgebungs-Verfahren, das Alignment der Bilder sowie die Segmentierung der Poren. Im Anschluss an die methodische Darstellung werden die Ergebnisse der quantitativen Gefügeanalyse präsentiert und ein Vergleich zwischen der Aussagekraft der quantitativen Parameter von 3D- und 2D-Abbildungen diskutiert. Bei der Analyse von über 10.000 Poren konnte eine Korrelation zwischen der Form und der Porengröße aufgezeigt werden. Weiterhin konnte aufgezeigt werden, dass eine 2D-Abbildung der Werkstoffoberfläche nicht ausreichend für eine eindeutige quantitative Beschreibung der Porosität ist. KW - 3D Metallographie KW - RASI KW - Porenstruktur PY - 2025 DO - https://doi.org/10.1515/pm-2025-0049 SN - 2195-8599 VL - 62 IS - 8 SP - 516 EP - 535 PB - De Gruyter Brill AN - OPUS4-63930 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk T1 - Fraktographie mit Hilfe von klassischen Methoden und Machine Learning – bisherige Erfahrungen und Anwendung auf weitere Fragestellungen N2 - In der Schadensanalyse und bei der Bewertung von mechanischen Experimenten liefert die Fraktographie Informationen über die vorliegenden Bruchmerkmale und den Bruchmechanismus eines Bauteils oder einer Probe. Im Rahmen des DGM AK Fraktographie werden an metallischen Werkstoffen Vergleichsexperimente durchgeführt und die Ergebnisse in einer Datenbank zur Verfügung gestellt. In einem Vorhaben wurde die Analyse von Bruchmerkmalen mittels Topographie-Daten und Machine Learning erprobt. Die gewonnenen Erfahrungen könnten auf weitere Anwendungsfälle wie z.B. Schweißverbindungen angewendet werden. T2 - Erfahrungsaustausch Werkstoff- und Bauteilprüfung CY - Halle, Germany DA - 04.09.2025 KW - Fraktographie KW - Machine Learning KW - Schadensanalyse KW - Schweißverbindungen PY - 2025 AN - OPUS4-64032 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Colombo, Marta A1 - Mostoni, Silvia A1 - Fredi, Giulia A1 - Rodricks, Carol A1 - Kalinka, Gerhard A1 - Riva, Massimiliano A1 - Vassallo, Andrea A1 - Di Credico, Barbara A1 - Scotti, Roberto A1 - Zappalorto, Michele A1 - D'Arienzo, Massimiliano T1 - Interfacial Chemistry Behind Damage Monitoring in Glass Fiber‐Reinforced Composites: Attempts and Perspectives N2 - Glass Fiber Reinforced Polymers (GFRPs) are widely used in structural applications but degrade over time due to internal damage. Structural Health Monitoring (SHM) enables early damage detection, improving reliability and reducing maintenance costs. Traditional SHM methods are often invasive and expensive. An emerging solution involves the embedding of carbon‐based filler like carbon nanotubes and reduced graphene oxide into GFRPs, forming conductive networks that detect damage through resistance changes. However, poor adhesion among GF, filler, and matrix can reduce mechanical performance. Therefore, tailoring GF and filler surface chemistry is essential to enhance durability and enable effective self‐sensing properties. This review summarizes the most recent efforts in modifying GF with carbon‐based filler to design GFRP with improved sensing ability and mechanical performance. After a brief introduction on the role of SHM solutions in early damage detection, an overview of the common GF and filler used in GFRPs will be provided. Then, the most relevant GF modification strategies exploited to incorporate carbon‐based filler in GFRPs will be described, focusing on the chemical grafting approach, which allows a careful optimization of the fiber/matrix interface. Last, a concise summary of the key mechanical and electrical tests to evaluate interfacial adhesion and self‐sensing will be supplied. KW - Review KW - Interface KW - Micromechanics KW - Polymer matrix composites KW - Glass fibre reinforced composites PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639934 DO - https://doi.org/10.1002/pc.70332 SN - 0272-8397 SP - 1 EP - 30 PB - Wiley AN - OPUS4-63993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Data-Driven Materials Science: Reproducibility and Standardization N2 - Advancing development and digitalization in materials science requires to focus on quality assurance, interoperability, and compliance with FAIR principles. Semantic technologies offer effective solutions for these challenges by enabling the storage, processing, and contextualization of data in machine-actionable and human-readable formats – essential for robust data management. This presentation highlights the PMD Core Ontology 3.0 (PMDco 3.0), developed specifically for the field of materials science and engineering, and its implementation within generic knowledge representation frameworks. Demonstrators such as standardized mechanical testing, material processing workflows, and the Orowan Demonstrator exemplify the ontology’s practical applications. The use of graph patterns, able to be compiled into rule-based semantic shapes, supports a unified and automated approach to managing heterogeneous experimental data across domains. T2 - Persson Group Seminar CY - Berkeley, CA, USA DA - 23.06.2025 KW - Semantic Data KW - Data Integration KW - Digitalization KW - Data Interoperability KW - PMD Core Ontology KW - Graph Patterns PY - 2025 AN - OPUS4-63484 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moschetti, Michael T1 - Capabilities and Applications of the Robot-Assisted Serial-Sectioning and Imaging (RASI) System N2 - The Robot-Assisted Serial-sectioning and Imaging (RASI) system at BAM provides automated, high-resolution 3D microstructural characterization for diverse materials. Integrating robotics with precision sectioning, etching, and optical microscopy, RASI reconstructs large volumes (approaching 15 × 15 × 15 mm³) with sub-micron detail. This presentation showcases RASI’s versatility through case studies on cast irons, sintered and additively manufactured steels, and ceramic-metallic packages. We demonstrate how RASI reveals true 3D architectures of features like graphite networks, pores, melt pools, and defects, often missed by 2D analysis. These quantitative datasets elucidate process-microstructure-property relationships and provide crucial 'ground truth' for validating computational models and developing digital twins. Ongoing RASI enhancements will also be highlighted. T2 - The 7th International Congress on 3D Materials Science (3DMS 2025) CY - Anaheim, CA, USA DA - 15.06.2025 KW - 3D microstructural characterization KW - Deep learning image segmentation KW - High-throughput materials analysis KW - Advanced materials’ development PY - 2025 AN - OPUS4-63693 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Blaeß, Carsten A1 - Boccaccini, A. R. A1 - Müller, Ralf T1 - Sintering and Crystallization of Fluoride-Containing Bioactive Glass F3 N2 - The fluoride-containing bioactive glass F3 with nominal composition (mol%) 44.8 SiO2 - 2.5 P2O3 - 36.5 CaO - 6.6 Na2O - 6.6 K2O - 3.0 CaF2 is a highly promising candidate for bone replacement applications. Its strong crystallization tendency, however, requires a thorough understanding of the interplay between glass powder particle size, surface crystallization, and sintering. Therefore, this study characterizes the sintering and crystallization of bulk specimens and various particle size fractions by differential thermal-analysis, laser scanning, electron microscopy, X-ray diffraction, and Infrared spectroscopy. Particle size fractions < 56 µm were found to fully densify, while crystals growing from the glass particle surface retard sintering of coarser fractions. Small amounts of a non-stoichiometrically calcium phosphosilicate (Ca14.92(PO4)2.35(SiO4)5.65) occurs as the primary crystal phase followed by combeite (Na4Ca4[Si6O18]) as a temporarily dominating phase. The surface crystallization of both pha­ses was found to be mainly responsible for sinter retardation. During later stages of crystallization, additional phases such as cuspidine (Ca4F2Si2O7) and silicorhenanite (Na2Ca4(PO4)2SiO4) occur, but finally monoclinic wollastonite (CaSiO3) forms as the dominant phase. KW - Bioactive Glass KW - Sintering KW - Crystallization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632482 DO - https://doi.org/10.52825/glass-europe.v3i.2564 SN - 2940-8830 VL - 3 SP - 105 EP - 124 AN - OPUS4-63248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Waurischk, Tina A1 - Deubener, J. A1 - Müller, Ralf T1 - Internal friction and energy dissipation during fracture in silicate glasses N2 - To obtain a deeper insight into the nature of energy dissipation during fracture, the internal friction of 13 borosilicate, aluminosilicate, soda-lime, and lead-containing glasses, for which inert crack growth data are known, was measured using dynamic mechanical thermal analysis. For asymmetrically bent glass beams, the loss tangent, tan δ, was determined between 0.2 and 50 Hz at temperatures between 273 K and the glass transition temperature, Tg. It was found that the area under the tan δ vs T·Tg−1 curve correlates with the crack growth exponent, n, in the empirical v = v0·KIn relation between crack growth velocity, v, and stress intensity, KI, which indicates that n correlates with the degree of energy dissipation of sub-Tg relaxation phenomena. KW - Glass KW - Internal friction KW - Crack growth PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631582 DO - https://doi.org/10.1063/5.0255432 SN - 0021-9606 VL - 162 IS - 19 SP - 1 EP - 9 PB - AIP Publishing AN - OPUS4-63158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pan, Z. A1 - Waurischk, Tina A1 - Duval, A. A1 - Müller, Ralf A1 - Deubener, J. A1 - Krishnan, N. M. A. A1 - Wondraczek, K. A1 - Wondraczek, L. T1 - Precise Real‐Time Measurement of Liquid Viscosity Using Digital Video Data N2 - Quantitative knowledge of liquid viscosity is of fundamental importance in many areas of materials synthesis and processing. However, the determination of viscosity often relies on specialized experimental equipment, offline experimentation, or invasive procedures, in particular when required in extreme conditions such as at high temperature, high pressure, and in confined or corrosive environments. Here, this study proposes and validates a fast and simple method that mimics the intuitive perception of liquid flow within a quantitative framework. For this, this study employs digital video observation to derive quantitative values of the shear viscosity of liquids, with high precision and rapid acquisition rates. The technique involves capturing liquid dynamics after minor mechanical stimulation. Processed imaging data are indexed by similarity and referenced to a digital database generated with a finite element model, from which values of viscosity are obtained in line. The approach is tested on water at room temperature and on a high‐temperature glass melt. Covering a viscosity range of four orders of magnitude, both yield convincing agreement with tabulated reference data at low computational cost. KW - Image analyses KW - Liquids KW - Materials discovery KW - Similarity analyses KW - Viscosities PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634606 DO - https://doi.org/10.1002/aisy.202500297 SN - 2640-4567 SP - 1 EP - 12 PB - Wiley AN - OPUS4-63460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chen, Ya‐Fan A1 - Arendt, Felix A1 - Bornhöft, Hansjörg A1 - de Camargo, Andréa S. S. A1 - Deubener, Joachim A1 - Diegeler, Andreas A1 - Gogula, Shravya A1 - Contreras Jaimes, Altair T. A1 - Kempf, Sebastian A1 - Kilo, Martin A1 - Limbach, René A1 - Müller, Ralf A1 - Niebergall, Rick A1 - Pan, Zhiwen A1 - Puppe, Frank A1 - Reinsch, Stefan A1 - Schottner, Gerhard A1 - Stier, Simon A1 - Waurischk, Tina A1 - Wondraczek, Lothar A1 - Sierka, Marek T1 - Ontology‐Based Digital Infrastructure for Data‐Driven Glass Development N2 - The development of new glasses is often hampered by inefficient trial‐and‐error approaches. The traditional glass manufacturing process is not only time‐consuming, but also difficult to reproduce with inevitable variations in process parameters. These challenges are addressed by implementing an ontology‐based digital infrastructure coupled with a robotic melting system. This system facilitates high‐throughput glass synthesis and ensures the collection of consistent process data. In addition, the digital infrastructure includes machine learning models for predicting glass properties and a tool for extracting patent information. Current glass databases have significant gaps in the relationships between compositions, process parameters, and properties due to inconsistent studies and nonconforming units. In addition, process parameters are often omitted, and even original literature references provide limited information. By continuously expanding the database with consistent, high‐quality data, it is aimed to fill these gaps and accelerate the glass development process. KW - Digitalisation KW - Data-driven glass development KW - Ontology PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625844 DO - https://doi.org/10.1002/adem.202401560 SN - 1527-2648 SP - 1 EP - 12 PB - Wiley VHC-Verlag AN - OPUS4-62584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Blaeß, Carsten A1 - Müller, Ralf T1 - Fast crack healing in glass-matrix composites with rigid filler percolation frameworks N2 - To ensure the durability of solid oxide fuel cell sealants, the understanding of the microstructural influence on viscous crack healing is essential. To this end, the effect of microstructure with respect to the spatial distribution of filler particles on viscous crack healing was studied with confocal laser scanning microscopy in glass-matrix composites (GMCs) made by mix-milling and sintering of sodalime magnesium silicate glass and Φ ≈ 6 vol% ZrO2 chemically inert rigid filler particles. This way, no change in Φ occurred during the crack healing treatments studied on Vickers indentation-induced radial cracks in polished GMC surfaces. Different microstructures were mimicked using different ZrO2 particle sizes for mix-milling. Unlike coarse ZrO2 particles, similar in size to the glass particle, fine ZrO2 particles, much smaller than the glass particles, form a rigid percolation framework (RPF) of ZrO2 filler particles around the former glass particles or glass particle agglomerates. For this RPF microstructure, crack healing was observed more readily as crack healing retardation phenomena like large-scale crack widening and crack tip rounding were strongly reduced, whereas narrow cracks could still heal locally within the glassy regions. KW - Crack healing KW - Glass matrix composite KW - Rigid percolation frameworks KW - Vickers indentation PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625921 DO - https://doi.org/10.1111/jace.20386 SN - 0002-7820 SP - 1 EP - 10 PB - Wiley AN - OPUS4-62592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zaiser, E. A1 - Fantin, Andrea A1 - Manzoni, Anna Maria A1 - Hesse, René A1 - Többens, D. M. A1 - Hsu, W.-C. A1 - Murakami, H. A1 - Yeh, A.-C. A1 - Pavel, M. J. A1 - Weaver, M. L. A1 - Zhu, H. A1 - Wu, Y. A1 - Vogel, F. T1 - Elucidating hierarchical microstructures in high entropy superalloys: An integrated multiscale study N2 - In this study, we examine a high entropy superalloy (HESA-Y1: Ni49.37Co20Cr7Fe4Al11.6Ti6Re1Mo0.5W0.5Hf0.03 at%), focusing on hierarchical microstructure formation and its effects on mechanical properties. Thermodynamic modeling using Thermo-Calc predicts equilibrium phase fractions, compositions, and transition temperatures,which are validated by experimental data from differential scanning calorimetry (DSC). Transmission electronmicroscopy (TEM) reveals that secondary aging induces nanometer-sized γ particles within γ’ precipitates, forming a hierarchical γ/γ’ microstructure. Atom probe tomography (APT) confirms supersaturation of γ’ precipitates with γ-forming elements (Co, Cr, Fe), driving γ particle formation, and measures interfacial widths between γ’ and γ phases. Partitioning coefficients derived from APT align with Thermo-Calc predictions for most elements. Vickers microhardness testing shows an increase of about 50 HV in the hierarchical microstructure compared to the conventional one. In situ synchrotron X-ray diffraction (XRD) from 25 to 750 ◦C determines a small, negative lattice misfit δ between γ and γ’ phases, suggesting enhanced microstructural stability, consistent with Thermo-Calc calculations. Our methodological approach enables measurement of the unconstrained lattice parameter of phase-extracted γ’ in a single-crystal XRD setup. Due to their small size and low volume fraction, γ particles do not produce distinct reflections in the X-ray diffractogram. Elucidating hierarchical microstructures across multiple scales, we establish that the presence of Re and Hf and controlled aging processes lead to enhanced mechanical properties, offering valuable insights for the design of advanced high entropy superalloys. KW - High entropy alloys KW - Transmission electron microscopy KW - X-ray diffraction KW - Superalloy PY - 2025 DO - https://doi.org/10.1016/j.matchar.2024.114642 VL - 220 SP - 1 EP - 13 PB - Elsevier Inc. AN - OPUS4-62348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manzoni, Anna Maria A1 - Mohring, Wencke A1 - Schneider, Mike A1 - Laplanche, Guillaume A1 - Hagen, Sebastian Peter A1 - Stephan‐Scherb, Christiane T1 - High‐Temperature Oxidation of the CrFeNi Medium‐Entropy Alloy N2 - The isothermal high‐temperature oxidation behavior of the equiatomic CrFeNi medium‐entropy alloy is a key issue that determines whether this material is suited for high‐temperature application. In this view, the understanding of the long‐term behavior is even more crucial than short‐term corrosion effects. Herein, a single‐phase CrFeNi alloy of the face‐centered‐cubic structure is exposed to synthetic air at 1000, 1050, and 1100 °C for 24, 100, and 1000 h and its oxidation behavior is systematically compared to that of 316L steel, which shows a surprising initial oxidation stabilization during early stages. The oxidation rate of CrFeNi is parabolic at 1000 °C (with a parabolic constant kp = 1.4·10−5 mg−2 cm−4 s−1) and 1050 °C (kp = 2.7·10−5 mg−2 cm−4 s−1), but breakaway oxidation occurs at 1100 °C after 4 h of exposure. In all cases, the oxide scales are found to (at least) partially spall off. Chromium diffuses outward to form a Cr2O3 layer at the gas/oxide interface, and a thin layer of (Cr, Fe, Ni)3O4 is identified at the oxide/alloy interface. Unlike the 316L alloy, which contains more Mn and Fe, the CrFeNi alloy does not show any catastrophic oxidation behavior at the investigated conditions. KW - Corrosion KW - Medium-entropy alloy KW - Scanning electron microscopy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636672 DO - https://doi.org/10.1002/adem.202500400 SN - 1438-1656 SP - 1 EP - 14 PB - Wiley VHC-Verlag AN - OPUS4-63667 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano-Munoz, Itziar A1 - Agudo Jácome, Leonardo A1 - Thompsom, Sean A1 - Schneider, Judy T1 - On the transferability of post-processing heat treatments designed for PBF-LB IN718 alloys to directed energy deposition specimens N2 - Many processes are being developed for metal additive manufacturing (AM) which vary by their heat source and feedstock. The use of directed energy deposition (DED) is growing due to its ability to build larger structures outside of a contained powder bed chamber. However, the only standard exclusively for post-build heat treatment of AM IN718 is ASTM standard F3055-14a, developed for powder bed fusion (PBF). This study evaluates the applicability of this current heat treatment standard to AM IN718 specimens produced using two methods of DED: laser-blown powder (LP)-DED and arc-wire (AW)-DED. Electron microscopy and X-ray diffraction techniques were used to characterize the specimens in the as-built condition and after the full heat treatment (FHT) specified in F3055. No evidence of remaining Laves phase was observed in the two DED specimens after the FHT. Yield strengths for the DED specimens were 1049 MPa for FHT AW-DED and 1096 MPa for LP-DED, higher than the minimum stated for PBF-LB IN718 of 920 MPa. The size, morphology, inter-spacing, and diffraction patterns of the γ´ and γ´´ strengthening precipitates are found to be similar for both DED processes. Differences were observed in the microstructure evolution where the F3055 heat treatments resulted in partial recrystallization of the grain structure, with a higher content of annealing twins observed in the AW-DED. These microstructural differences correlate with differences in the resulting elongation to failure. Thus, it is proposed that variations in heat treatments are needed for optimizing IN718 produced by different AM processes. KW - Additive manufacturing variants KW - Directed energy deposition (DED) KW - Post-process heat treatments KW - SEM-EBSD and TEM microscopy KW - XRD phase analysis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628165 DO - https://doi.org/10.1007/s00170-025-15386-1 SN - 1433-3015 VL - 137 IS - 7-8 SP - 3949 EP - 3965 PB - Springer Science and Business Media LLC AN - OPUS4-62816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weinel, Kristina A1 - Hahn, Marc Benjamin A1 - Lubk, Axel A1 - González Martínez, Ignacio Guillermo A1 - Büchner, Bernd A1 - Agudo Jácome, Leonardo T1 - Nanoparticle Synthesis by Precursor Irradiation with Low-Energy Electrons N2 - Nanoparticles (NPs) and their fabrication routes are intensely studied for their wide range of application in optics, chemistry, and medicine. Γ-ray and ion irradiation of precursor matter are established methods that facilitate tailored NP synthesis without complicated chemistry. Here, we develop and explore NP synthesis based on irradiating precursor microparticles with low-energy electron beams. We specifically demonstrate the fabrication of plasmonic gold nanoparticles of sizes between 3 and 350 nm on an amorphous SiOx substrate using a 30 kV electron beam. By detailed comparison with electron scattering simulations and thermodynamic modeling, we reveal the dominant role of inelastic electron–matter interaction and subsequent localized heating for the observed vaporization of the precursor gold microparticles. This general principle suggests the suitability of electron-beam irradiation for synthesizing NPs of a wide class of materials. KW - Gold Nanoparticle KW - Scanning Electron Microscopy KW - In situ irradiation KW - Thermodynamic modelling KW - Heat Transfer PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627609 DO - https://doi.org/10.1021/acsanm.4c06033 SN - 2574-0970 VL - 8 IS - 10 SP - 4980 EP - 4988 PB - ACS Publications CY - Washington, DC AN - OPUS4-62760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feng, Wen A1 - Schulz, Johannes A1 - Wolf, Daniel A1 - Pylypenko, Sergii A1 - Gemming, Thomas A1 - Weinel, Kristina A1 - Agudo Jácome, Leonardo A1 - Büchner, Bernd A1 - Lubk, Axel T1 - Secondary electron emission from gold microparticles in a transmission electron microscope: comparison of Monte Carlo simulations with experimental results N2 - We measure the electron beam-induced current to analyze the electron-induced secondary electron (SE) emission from micron-sized gold particles illuminated by 80 and 300 keV electrons in a transmission electron microscope. A direct comparison of the experimental and simulated SE emission (SEE) employing Monte Carlo scattering simulations based on the GEANT4 toolkit yields overall good agreement with a noticeable discrepancy arising from the shortcoming of the GEANT4 scattering cross sections in the low-loss regime. Thus, the electron beam-induced current analysis allows to quantify the inelastic scattering including SEE in the transmission electron microscope and provides further insight into the charging mechanisms. KW - Electron beam-induced current KW - Transmission electron microscopy KW - Secondary electron emission KW - Secondary electron yield KW - Gold micronoparticle PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-622557 DO - https://doi.org/10.1088/1361-6463/ad9840 VL - 58 IS - 8 SP - 1 EP - 7 PB - IOP Publishing CY - Bristol, GB AN - OPUS4-62255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paulisch-Rinke, M. C. A1 - Manzoni, Anna Maria A1 - Agudo Jácome, Leonardo A1 - Vogel, F. A1 - Reimers, W. T1 - Influence of chemical composition on microstructure and mechanical properties in the extruded aluminum alloys 7021B and 7175 N2 - The aim of this study is to improve the mechanical properties of Al 7xxx series alloys by achieving the strengthening benefits typically provided by Cu while avoiding the formation of low-melting eutectic phases associated with excessive Cu content. This is accomplished through a tailored combination of alloying elements and optimized thermomechanical treatments. Alloys 7021B (high Zn content) and 7175 (high Cu and Mg content) are analyzed and optimized threefold in this study: the heat treatment, the microstructural evolution and the mechanical properties are investigated by several methods and compared with the aim of improving the process parameters for subsequent application. The peak-aging process is optimized via compression tests to overcome the strength-ductility trade-off. Microstructure and phase chemistry analyses by transmission electron microscopy and atom probe tomography enable a better understanding of the underlying morphological features such as the spatial distribution, and the chemical composition of the hardening phases. The mechanical properties of the peak-aged alloys are determined by compression and tensile tests. Both alloys exhibit very high strength – even by 7xxx series standards. It can be traced back to the dislocation movement: it is impeded both by homogeneously distributed cuttable Guinier–Preston zones in both alloys and by non-cuttable η’ precipitates. As a result, we demonstrate that alloy 7021B offers novel possibilities for processing and industrial application: high strength, typically associated with Cu containing alloys, can also be obtained in Cu free alloys, if the Zn content is sufficiently high. We can thus suggest new opportunities for processing and industrial applications by reducing the risk of forming low-melting eutectic phases. KW - Aluminium alloys KW - Transmission electron microscopy KW - Atom probe tomography KW - Extrusion KW - Mechanical properties PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640338 DO - https://doi.org/10.1016/j.matdes.2025.114649 SN - 0264-1275 VL - 258 SP - 1 EP - 11 PB - Elsevier Ltd. AN - OPUS4-64033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller-Elmau, Johanna A1 - Göbel, Artur A1 - Junge, Paul A1 - Müller, Julian A1 - Rousseau, Tom A1 - Görke, Oliver A1 - Nikasch, Christian A1 - Kiliani, Stefan T1 - Thermal cycling of YAG infiltration and plasma sprayed coatings as environmental barrier coating on ceramic heat shields for use in hydrogen operating gas turbines N2 - Environmental barrier coatings (EBC) are intended to protect alumina ceramic tiles in hot water vapor conditions, enabling gas turbines to operate with higher hydrogen content or even pure hydrogen. For these operating conditions, yttrium aluminum garnet (YAG) promises the highest protection against hydrolysis, which can be applied via atmospheric plasmaspraying (APS). To enhance the protection efficiency, the coating is combined with a prior infiltration of the base material. The obtained design acts as in-depth protection even if the coating exhibits cracks. KW - Thermal shock KW - Thermal cycles KW - Environmental barrier coating (EBC) KW - Water vapor corrosion PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639829 DO - https://doi.org/10.1016/j.oceram.2025.100837 VL - 23 SP - 1 EP - 7 PB - Elsevier Ltd. AN - OPUS4-63982 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo T1 - In situ electron-beam 'melting' (sublimation) of gold microparticles in the SEM N2 - Gold micro particles have been modified in the past using the high power density of a localized electron beam of acceleration voltages above 100 kV as an energy source to transform matter at the sub-micron scale in a transmission electron microscope uses. Here, the e-beam-induced transformation of precursor microparticles employing a low-energy e-beam with an acceleration voltage of 30 kV in a scanning electron microscope is implemented. Under these conditions, the technique can be classified between e-beam lithography, where the e-beam is used to mill holes in or grow some different material onto a substrate, and e-beam welding, where matter can be welded together when overcoming the melting phase. Modifying gold microparticles on an amorphous SiOx substrate reveals the dominant role of inelastic electron-matter interaction and subsequent localized heating for the observed melting and vaporization of the precursor microparticles under the electron beam. Monte-Carlo scattering simulations and thermodynamic modeling further support the findings. T2 - IKZ International Fellowship Award & Summer School 2025 from May 5 to 7, 2025 CY - Berlin, Germany DA - 05.05.2025 KW - Gold Nanoparticle KW - Scanning Electron Microscopy KW - In situ irradiation KW - Thermodynamic modelling KW - Heat Transfer PY - 2025 AN - OPUS4-63256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk T1 - Ergebnisse eines Ringversuchs zur quantitativen Analyse von Schwingstreifen auf Bruchflächen metallischer Werkstoffe N2 - Die Frage nach der Anzahl der Lastspiele bis zum Bruch eines Bauteils wird in der Schadensanalyse oft gestellt – und kann meistens gar nicht oder nicht mit befriedigender Sicherheit beantwortet werden. Selbst wenn ein duktiler Werkstoff vorliegt, der unter schwingender Beanspruchung prinzipiell Schwingstreifen ausbilden kann, ist nicht sicher, ob diese vollzählig erkannt werden können und ob jeder Schwingstreifen auf einem Lastspiel beruht. Im Arbeitskreis Fraktographie wurde ein Ringversuch durchgeführt, bei dem an Bruchflächen und an Bildern dieser Bruchflächen Schwingstreifenabstände bestimmt werden sollten. Insgesamt 70 Teilnehmer/innen aus Industrie und Forschung haben daran teilgenommen. Die aufgebrachten Lastspielzahlen und Rissfortschritte lagen vor, waren den Teilnehmern aber nicht bekannt. Obwohl diese überwiegend erfahrene Fachkräfte sind, waren die Streuungen der Ergebnisse unerwartet groß. Es wird diskutiert, woran das liegt und wie die Situation verbessert werden kann. T2 - DGM Metallographietagung 2025 CY - Bochum, Germany DA - 08.10.2025 KW - Fraktographie PY - 2025 AN - OPUS4-64344 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - On Shared Vocabulary, Ontologies, Semantic Data and Prototype Applications N2 - The advancement of development and digitalization in materials science necessitates rigorous quality assurance, interoperability, and adherence to FAIR principles. Semantic technologies contribute to these objectives by facilitating the structured storage, processing, and contextualization of data, yielding machine-actionable and human-interpretable knowledge representations vital for modern data management. This presentation showcases the prototypical application of generic approaches of knowledge representation in materials science. It includes the design and documentation of graph patterns that may be compiled into rule-based semantic shapes. The development and application of the PMD Core Ontology 3.0 (PMDco 3.0) tailored for materials science is highlighted. Its integration into daily lab life is demonstrated through its functional incorporation into electronic lab notebooks (ELN). In this respect, a possible integration of semantic technologies into openBIS is presented. The openBIS system is usable as a central data storage system that may be complimented by semantic annotation of data to enhance data contextualization and automation. Graph-based knowledge representations and rule-based semantic shapes are shown which were developed alongside the PMD Core Ontology 3.0 (PMDco 3.0) and can enrich openBIS functionalities. Practical examples from material processing and mechanical testing illustrate how semantic extensions of openBIS enable machine-actionable, interoperable, and reusable research data, paving the way for a unified, ontology-driven laboratory data ecosystem. T2 - openBIS User Group Meeting (openBIS UGM) CY - Berlin, Germany DA - 22.09.2025 KW - Semantic Data KW - Data Integration KW - Digitalization KW - OpenBIS KW - Ontologies KW - Graph Patterns PY - 2025 AN - OPUS4-64307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. I. A1 - Nolze, Gert A1 - Malakhov, A. Yu. A1 - Pervukhina, O. L. T1 - Investigation of the Structure of Interfaces Between Metals and Alloys Joined by Explosion Welding N2 - The structure of interfaces in Fe20Cr6Al/Cu, titanium/steel and brass/Invar bimetals obtained by explosion welding from sheet components with a thickness of 1 and 4, 25 and 5, 12 and 8 mm, respectively, was studied using analytical methods of scanning electron microscopy. The wave dimensions (length/height) were approximately 200/50 μm for Fe20Cr6Al/Cu, 700/70 μm for titanium/steel and 350/100 μm for brass/Invar. At the micron scale, mutual penetration of the welded components into each other (trans-interface diffusion) was not detected. In the iron-based plate of Fe20Cr6Al/Cu bimetal, a strong texture and cracks, which are a critical defect, were formed as a result of severe plastic deformation. Less pronounced textures were revealed in the components of titanium/steel bimetal. In titanium/steel bimetal, Laves phase particles Fe2Ti were found near the welded interface, while in brass/Invar bimetal, local contact melting was observed. However, the particles Fe2Ti and local melting areas are not critical defects, as they do not cause unacceptable deterioration in the adhesive strength of the welded joints, which was confirmed by a high shear strength of 500-570 MPa for the brass/Invar bimetal. KW - EBSD KW - Welding KW - Interface PY - 2025 DO - https://doi.org/10.1007/s11665-025-12660-x SN - 1059-9495 SP - 1 EP - 11 PB - Springer Science and Business Media LLC AN - OPUS4-64732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fayis Kalady, Mohammed A1 - Schultz, Johannes A1 - Weinel, Kristina A1 - Wolf, Daniel A1 - Lubk, Axel T1 - Geometry-dependent localization of surface plasmons on random gold nanoparticle assemblies N2 - Assemblies of plasmonic nanoparticles (NPs) support hybridized modes of localized surface plasmons (LSPs), which delocalize in geometrically well-ordered arrangements. Here, the hybridization behavior of LSPs in geometrically completely disordered two-dimensional arrangements of Au NPs fabricated by an e-beam synthesis method is studied. Employing electron energy loss spectroscopy in a scanning transmission electron microscope and numerical simulations, the disorder-driven spatial and spectral localization of the coupled LSP modes that depends on the NP thickness is revealed. Below a NP thickness of 0.4 nm, localization increases toward higher hybridized LSP mode energies. In comparison, above 10 nm thickness, a decrease of localization toward higher mode energies is observed. In the intermediate thickness regime, a transition of the energy dependence of the localization between the two limiting cases, exhibiting a mode energy with minimal localization, is observed. It is shown that this behavior is mainly driven by the energy and thickness dependence of the polarizability of the individual NPs. KW - Gold Nanoparticles KW - Surface plasmons KW - Electron enerdy loss spectroscopy (EELS) KW - scanning transmission electron microscopy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647230 DO - https://doi.org/10.1103/44nk-6bp2 SN - 2643-1564 VL - 7 IS - 043053 EP - 4 PB - American Physical Society AN - OPUS4-64723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna T1 - High-temperature in-situ investigation of refractory high entropy superalloys N2 - The spinodal decomposition in bcc structured refractory alloys can be used as a potential strengthening mechanism, as has been demonstrated over the last decade in research on high entropy alloys and compositionally complex alloys. Early work from the 1990s already showed the possibility of further enhancing this spinodal decomposition by adding the element Al, which in addition to spinodal decomposition also provides an ordering process in the otherwise disordered bcc phases of the alloy. Nevertheless, the knowledge of refractory high entropy (super)alloy systems, is still in its infancy and requires further research to fully exploit its potential for high temperature applications in the future. Two refractory alloys of the Al-Nb-Ta-Ti-Zr family are investigated via (high temperature in-situ) XRD, in the long run for understanding spinodal decomposition properties. Ex-situ XRD and TEM observations show the formation of at least one bcc phase and an ordered B2 phase. In addition, one or more Al-Zr rich phases are observed, which are not part of the spinodal phases and are unwanted. The high-temperature observations at 1000°C for 60 h show a remarkable increase in peak width up to 2° FWHM that does not disappear after cooling in the furnace. Ex-situ observations after 1000°C for hundreds of hours and subsequent quenching show narrow peaks (max 0,2° FWHM) at the same position. This and several other observations will be presented in this talk and possible explanations are presented. T2 - Euromat 2025 CY - Granada, Spain DA - 14.09.2025 KW - High-entropy alloys KW - Superalloys KW - X-ray diffraction KW - In-situ KW - Scanning electron microscopy PY - 2025 AN - OPUS4-64840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Xu, Alan A1 - Moschetti, Michael A1 - Miskovic, David A1 - Wei, Tao A1 - Ionescu, Mihail A1 - Wang, Zhiyang A1 - Palmer, Tim A1 - Bhattacharyya, Dhriti A1 - He, Peidong A1 - Li, Xiaopeng A1 - Gludovatz, Bernd A1 - Ferry, Michael T1 - Improved irradiation resistance of a low activation refractory medium entropy alloy, VCrFeW0.2, for fusion applications demonstrated by micro-tensile testing N2 - An, as cast, VCrFeW0.2 refractory medium entropy alloy (RMEA) was designed for fusion reactor divertor applications, focusing on reduced cost, low activation and compositional stability (low transmutation rates). The as-cast alloy was irradiated to a fluence of 5.6 × 10^17 ions/cm^2 at room temperature with 5 MeV helium ions whose energy have been uniformly attenuated to 0.4 MeV and 5 MeV via energy degradation device prior to sample irradiation. Pre and post irradiation, its mechanical properties were evaluated micro-tensile testing. Prior to irradiation, the VCrFeW0.2 alloy demonstrated good strength and ductility, with a yield strength of 1464 MPa and strain to UTS (\sigma_UTS) of 4.6 %, maintaining comparable strength to pure tungsten (1403 MPa) but with greater strain to UTS (1.3 %). Post irradiation, the VCrFeW0.2 alloy exhibited remarkable damage resistance; its strength increased by only ∼160 MPa, and it retained strain to UTS with a \sigma_UTS of 2.9 %. It performed better than pure tungsten tested under identical irradiation conditions where there was ∼1800 MPa increase in yield strength and a complete loss of plasticity. The micro-tensile results were supported by nanoindentation tests and Vickers hardness testing was also undertaken to show the yield strength values are representative of macro scale, bulk behavior. TEM and comparison with existing literature on RMEA/RHEA are presented here to understand the reason for difference in performance between VCrFeW0.2 alloy and pure tungsten. KW - Refractory medium entropy alloys KW - Fusion reactor materials KW - Irradiation resistance KW - Micro-tensile testing KW - Helium ion damage PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-645322 DO - https://doi.org/10.1016/j.ijrmhm.2025.107481 SN - 0263-4368 VL - 134 SP - 1 EP - 16 PB - Elsevier Ltd. CY - Netherlands AN - OPUS4-64532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hébrard, Louis T1 - Comparison of Room and High Temperature Fatigue Behavior of a New LPBF VDM 780 Alloy N2 - The actual environmental challenges require a huge effort from all industrial sectors to reduce their emissions of greenhouse gasses and pollutants. In this context, aeronautics is deeply concerned as one of the most emissive industrial sectors (cf. EU Green Deal). The answer to this pressing challenge is complex and involves new fuels and engine concepts, new aerostructures with higher weight-savings, as well as new, energy-efficient, and sustainable manufacturing technologies and materials. Two technologies may contribute particularly to achieving the goals: (i) new and more energy-efficient processes such as additive manufacturing (AM) can be used for part production; (ii) the engine efficiency of airplanes can be significantly improved to save fuel and reduce gas emissions. The latter can be achieved by increasing the engine thermal efficiency, i.e., increasing the turbine inlet temperature. Currently, only single-crystalline cast materials are available to be used for the thermally highest-loaded parts in the gas turbine engine, i.e., the turbine blades in the high-pressure turbine just behind the combustion chamber. These materials rely on a special casting technology, although they lose these original material performances when additive manufactured. In addition, current materials suitable for metal additive manufacturing have a limited range of temperature application. Therefore, the focus is on the development of new materials targeting higher in-service operation temperatures and durability. Recently, a new Ni-based superalloy (VDM 780) has been developed to ensure microstructural stability up to 800 °C. The goal of this work is to provide a deeper understanding of the high temperature fatigue properties of this alloy. This will enable the identification of the maximum operating temperature of this alloy and assess its performance in order to establish its potential in view of a new generation of more efficient aero-engines. T2 - 11th Edition of Fatigue Design International Conference CY - Senlis, France DA - 19.11.2025 KW - Fatigue KW - Additive Manufacturing KW - Ni-based superalloy KW - High Temperature PY - 2025 AN - OPUS4-64992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Vom Experiment zur semantischen Wissensrepräsentation: Datenstandards und Interoperabilität in der Materialcharakterisierung N2 - Im Zeitalter der digitalen Transformation rückt die strukturierte Erfassung und semantische Verknüpfung von Materialcharakterisierungsdaten immer stärker in den Fokus, um eine effiziente Nutzung über Disziplin- und Projektgrenzen hinweg zu gewährleisten. Dabei bilden etablierte Datenstandards und semantische Technologien sowie Ontologien die Grundlage für eine nach FAIR-Kriterien aufgebaute Dateninfrastruktur, die sowohl maschinenlesbare als auch nachvollziehbare Wissensrepräsentationen ermöglicht. In dieser Präsentation sollen Prinzipien interoperabler Datenarchitekturen erläutert werden, wobei auf die Bedeutung normkonformer Modelle und semantischer Konzeptualisierungen eingegangen wird. Dabei wird der steigende Bedarf an verlässlichen, reproduzierbaren und wiederverwendbaren Daten im Bereich der Materialwissenschaft und Werkstofftechnik adressiert, der insbesondere die Materialcharakterisierung und Werkstoffprüfung vor neue Herausforderungen stellt. Hinsichtlich der angestrebten Möglichkeiten zum erleichterten Datenaustausch kommen einheitlichen Datenformaten und -beschreibungen eine besondere Bedeutung zu. Anhand ausgewählter Publikationen und Demonstratoren wird aufgezeigt, wie Ontologien als verbindende Zwischenschicht unterschiedliche Material- und Verfahrensdomänen konsistent abbilden und zusammenführen können. Ein praktischer Anwendungsfall verdeutlicht die RDF-basierte Repräsentation von Zugversuchsdaten und deren Einbettung in ein Triple-Store-Datenbank-Umfeld. Hierbei fließen Erfahrungen aus der Entwicklung und Anwendung der PMD Core Ontology (PMDco) sowie normenkonformer Ontologien (z.B. Tensile Test Ontology, TTO) ein, welche im Rahmen des Projektes Plattform MaterialDigital (PMD, materialdigital.de) erstellt und betrachtet wurden. Darüber hinaus werden weitere methodische Ansätze und Entwicklungen aus diesem Projekt illustriert. T2 - Tagung Werkstoffprüfung 2025 CY - Dresden, Germany DA - 27.11.2025 KW - Wissensrepräsentation KW - Ontologie KW - Werkstoffprüfung KW - Digitale Transformation KW - Interoperabilität PY - 2025 AN - OPUS4-64944 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marschall, Niklas T1 - Spinodal Decomposition in FeMnNiCoCu: Alloying effects N2 - Spinodal decomposition in multi-component alloys remains insufficiently understood, particularly when multiple driving forces govern phase evolution. Chemical thermodynamics provides reliable predictions of spinodal instabilities, but elastic energy contributions can significantly alter the boundaries of phase stability. In this work, we establish a framework to analyze phase stability in high-entropy alloys by combining Hessian-based spinodal analysis with convex hull constructions that capture miscibility gaps. This approach allows us to disentangle the roles of chemical, elastic, and kinetic factors in early-stage decomposition. Our results highlight how elastic contributions can extend the effective spinodal region beyond chemically predicted boundaries, thereby influencing microstructural pathways. This combined stability analysis offers new insights into the mechanisms governing decomposition and advancing the theoretical understanding of phase evolution in high-entropy alloys. T2 - FEMS EUROMAT 2025 CY - Granada, Spain DA - 14.09.2025 KW - High-entropy alloy KW - Elasticity KW - Phase stability KW - Hessian KW - Convex hull PY - 2025 AN - OPUS4-64263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenberg, Rainer T1 - Modelling of hydrogen-induced ductility loss in titanium-based hydrogen storage N2 - One promising solution for decarbonisation is the use of hydrogen as energy carrier. Besides its exceptional advantages like high calorific value, better safety and non-existent harmful emissions, one major challenge is still hydrogen embrittlement of Ttitanium alloys used as a hydrogen storage. In this work, a method is presented that can numerically model and determine a threshold concentration of hydrogen in solid solution responsible for a sudden ductile-to-brittle transition. The origin of this sudden loss of ductility lies in the segregation kinetics thermodynamics that is modelled together with an elastoplastic fracture mechanics model. Starting from experimental fracture mechanics test data, a meaningful coupling mechanism was found for the fracture mechanics cohesive zone model in the form of a segregation-modified cohesive energy that triggers an acceleration of crack extension above defined concentration values. It can be demonstrated that above a threshold of only few atomic percent hydrogen in the solid solution, the segregated hydrogen concentration exceeds 20 at.%. The current results present a mechanism that enables the modelling of the sudden ductility loss triggered by a segregation-affected crack energy expression in titanium alloys exposed to hydrogen. This method is not only applicable to other various materials but can also be a substantial benefit for the safety assessment of hydrogen storage devices. T2 - 5th EMMC International Workshop 2025 CY - Vienna, Austria DA - 08.04.2025 KW - Segregation Transition KW - Hydrogen Embrittlement KW - Titanium Alloys KW - Crack Propagation KW - Ductile-to-Brittle Transition PY - 2025 AN - OPUS4-63177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Murugan, Jegatheesan T1 - Extending Grain Boundary Phase Diagrams to Multi-Phase Boundary Diagrams N2 - Phase diagrams serve as fundamental blueprints for comprehending material behaviour and guiding material design. However, the phase diagrams are largely available only for the bulk phases. The thermodynamic properties and phase behaviour of defects, such as grain boundaries (GBs) and phase boundaries (PBs), are equally important for the safe design of materials. Recently, we developed CALPHAD-integrated density-based phase field model (DPF) to calculate the thermodynamic data of GBs. In the model, the GB was represented by a continuous relative atomic density field with reference to a single bulk density and a Gibbs free energy functional was derived. In this work, we extend the DPF model by re-deriving the Gibbs free energy functional for PBs lying between heterogeneous bulk phases of different atomic densities. Here, we use phase-specific atomic densities to normalize the phase properties on either side of the PB such that the relative density fields are continuous across the interface. Using the model, the multi-phase interfacial thermodynamic data are obtained and related phase boundary diagrams are constructed. We study binary and ternary Fe-Mn-X alloy systems. In the Fe-Mn multi-phase boundary diagram, a shrinkage in the α-ferrite region is observed. Integrated with CALPHAD databases, the developed model may be used to calculate the segregation of solute to the PBs, paving way to manipulate segregation behaviour for microstructure design. T2 - FEMS 2025 EUROMAT CY - Granada, Spain DA - 14.09.2025 KW - Phase boundary diagrams KW - Interface thermodynamics KW - CALPHAD PY - 2025 AN - OPUS4-64425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard T1 - On the modeling of creep anisotropy of single Crystal Superalloys at low temperatures and high stresses N2 - Low-Temperature High Stress (LTHS) creep plays a crucial role in Ni-base Superalloys, particularly affecting components like blades near the root. Below 850°C, the precipitate microstructure remains stable, characterized by periodically arranged ’ cubic precipitates surrounded by the -matrix. In these conditions, macroscopic traces of cubic slip have been observed in <111> oriented tensile specimens, whereas their microscopic origin has been a topic of debate [1]. Later, it was shown by Discrete Dislocations simulations [2] that the apparent cubic slip is rather due to a lack of hardening in <111> specimens, which is related to the special dislocation structures that develop in this case. Furthermore, in LTHS conditions, Superlattice Intrinsic, Extrinsic Stacking Faults (SISF/SESF), or micro-twins are also frequently reported in crept specimens. Usually, these mechanisms are investigated separately, so that a unified picture and a detailed understanding of these mechanisms and their activation conditions have only recently emerged in the literature, despite the intensive investigations of the last decades [3-5]. The objective of this work is to develop a dislocation-based constitutive law that includes these recent developments. In particular, the pseudo-cubic slip mechanism is considered as resulting from the lack of hardening in <111> oriented tensile specimens and is represented by a novel estimate of the back-stresses based on the spectral decomposition of a tensorial representation of the back-stress. An additional novelty is that SISF- and SESF-related slip systems are accounted for as distinct slip systems with corresponding dislocation densities. The model has been implemented as a user-defined constitutive law for commercial Finite Element codes and identified as well as validated with data from the literature obtained with <001>, <011> and <111> oriented crystals [3,6]. It can be used in combination with a Representative Volume Element of the grain structure for simulation of creep in polycrystalline superalloys, including additively manufactured materials [7]. T2 - Materials Structure and Micromechanics of Fracture CY - Brno, Czech Republic DA - 23.06.2025 KW - Creep KW - Superalloy KW - Crystal plasticity KW - Single crystal KW - Model PY - 2025 AN - OPUS4-63551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leo, Reinhold A1 - Sobol, Oded A1 - Hango, Silas Ithete A1 - Saliwan Neumann, Romeo A1 - Askar, Enis A1 - Boellinghaus, Thomas T1 - Ex-situ investigation of the compatibility of Duplex Stainless Steel for high-pressure hydrogen applications N2 - The key to a successful transition into clean energy carriers such as hydrogen requires the construction of safe transportation pipelines made of alloys which are not susceptible to hydrogen assisted cracking. Duplex Stainless Steels (DSS) are considered as a proper class for components because of their many distinctive qualities. As this consideration depends strongly on the susceptibility level to Hydrogen Assisted Cracking (HAC), the DSS class has been broadly investigated under electrochemical charging conditions. In this work, the interplay between several factors controlling the level of HAC, was examined using light microscopy, high-pressure gaseous hydrogen pre-charging, Electron Backscatter Diffraction (EBSD), tensile testing, fractography and hydrogen concentration measurements using Carrier Gas Hot Extraction (CGHE). The effect of gaseous hydrogen on the mechanical properties with the role of hydrogen induced phase transformation have been investigated both in unused material and in high pressure pipeline section. In contrary to the common electrochemical charging described broadly in the literature, no significant martensitic phase transformation of the austenitic phase was observed. On the other hand, the influence of hydrogen on parameters such as elongation at fracture and reduction of area was noticeable. It is concluded based on the performance of DSS in gaseous hydrogen, that this material has a better potential for utilization in hydrogen applications. As for future experiments, the intention is to analyse the impact of high-pressure gaseous hydrogen on the welded components of this grade, and under mechanical load using the hollow specimen technique. T2 - 5th International Conference on Metals and Hydrogen CY - Ghent, Belgium DA - 14.10.2025 KW - High-Pressure Hydrogen KW - Pipelines KW - Duplex Stainless Steels KW - Hydrogen Assisted Cracking KW - Hollow Specimen Technique PY - 2025 SN - 978-9-08179-424-4 SP - 1 EP - 19 AN - OPUS4-64426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Kianinejad, Kaveh T1 - Multiscale Modelling of Creep Anisotropy in Additively Manufactured IN738LC N2 - Excellent creep resistance at elevated temperatures, i.e. T / Tm> 0.5, due to gamma-gamma’ microstructure is one of the main properties of nickel-based superalloys. Due to its great importance for industrial applications, much research has been devoted to understanding the underlying deformation mechanism in a broad spectrum of temperature and loading conditions. Additive Manufactured (AMed) nickel-based superalloys, while being governed by similar \gamma-gamma’ microstructure, exhibit AM-process specific microstructural characteristics, such as columnar grains, firm crystallographic texture (typically <001> fibre texture parallel to build direction) and compositional inhomogeneity, which in turn leads to anisotropic creep response in both stationary and tertiary phases. Despite the recent insights on the correlation between process parameters and the resulting microstructure, these materials' anisotropic creep behaviour and corresponding deformation mechanism are insufficiently understood. One reason is the lack of capable material models that link the microstructure to the mechanical behaviour. Within the present work, a multiscale approach has been developed to overcome this challenge by combining microstructure-based mesoscale and phenomenological macroscale models. The mesoscale model utilizes the Crystal Plasticity Finite Element Method (CPFEM) to include the microstructural characteristics and the relevant deformation mechanism on the polycrystalline scale. The mesoscale model was then used to perform virtual creep experiments required to calibrate the macroscale model. The developed approach has been applied to characterise the creep behaviour of AMed IN738LC. The effect of different slip systems, crystallographical texture, grain morphology, and Grain Boundary Sliding (GBS) on creep anisotropy at 850°C has been investigated. The approach's ability to capture the AM-specific characteristics and link them to the observed macroscale anisotropic response has been demonstrated, and the contribution of primary underlying deformation mechanisms to creep anisotropy has been elucidated. KW - Creep anisotropy KW - Crystal plasticity KW - Addtively manufactured Nickel-based Alloys alloy PY - 2025 SP - 1 EP - 135 PB - RWTH Aachen CY - Aachen AN - OPUS4-64598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kianinejad, Kaveh A1 - Czediwoda, Fabian A1 - Glatzel, U. A1 - Völkl, R. A1 - Stöhr, B. A1 - Ávila Calderón, Luis A1 - Schriever, Sina A1 - Saliwan Neumann, Romeo A1 - Fedelich, Bernard A1 - Darvishi Kamachali, Reza T1 - Microstructure-based modelling of the anisotropic creep behaviour in additively manufactured INCONEL 718 N2 - The existing gap in the adequate prediction of the microstructure-property relationships remains a significant barrier to the safe application of the additively manufactured materials. This challenge is fundamentally tied to the intricate microstructural defects that emerge during the processing. Systematic microstructure-based modelling can offer solutions to address this bottleneck. In this work, we utilize a crystal plasticity model, developed for gamma''-strengthened Ni-base alloys and calibrated with single crystal tensile and creep tests of Inconel 718. By systematically refining the representative volume element complexity---from equiaxed to elongated grain morphologies, and from unimodal to bimodal orientation and grain size distributions---we demonstrate how each layer of structural realism contributes to the model’s predictive capacity. Creep tests of laser-based powder bed fusion (PBF-LB/M) manufactured samples in three orientations (with the tensile axis parallel, perpendicular, and 45° tilted relative to the building direction) were performed at 650° C, accompanied by electron backscatter secondary diffraction measurements. The results of our simulations reveal that the bimodal grain morphology and crystallographical texture significantly influence the observed creep anisotropy. We show that the elongated grain structure combined with grain boundary sliding plays a major role in the creep response, specifically in tilted specimens. KW - Additive manufactured Ni-base superalloys KW - Creep Anisotropy KW - Crystal plasticity PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646884 DO - https://doi.org/10.1016/j.msea.2025.149029 VL - 945 SP - 1 EP - 15 PB - Elsevier B.V. AN - OPUS4-64688 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kostenko, Yevgen T1 - Harmonizing Viscoplastic Material Model Application within the BMBF-Project “DigitalModelling” of the Platform Material Digital- Basic Idea, General Strategy and Current Status N2 - For decades, Germany stands for excellent cutting-edge research in the field of so-called higher-value constitutive visco-plastic material models and can draw on a large and globally unique pool of material data. However, both the data and the model structure are extremely heterogeneous and sometimes fundamentally different from research center to research center and from industrial partner to industrial partner. To address the heterogeneity in the material model landscape appropriately, an adaptable material model for the specific application and the specific material is required. The relevant parameters for the adapted material model must be identified as objectively and automatically as possible. To achieve a potentially real-time capable implementation, the material model equation system should be abstracted. The “DigitalModeling” project, organized within the German Platform initiative Material Digital, aims to create a standard and an interface that harmonize the scientific and technical development of constitutive, visco-plastic material models, increase their visibility and maximize the productivity of future research funding. This presentation summarizes the basic idea, the strategy behind it as well as the current status of the project, which was started beginning of 2024. T2 - vgbe Workshop with Technical Exhibition Materials & Quality Assurance CY - Bergen, Norway DA - 07.05.2025 KW - Visco-plastic Material Model KW - Simulation Workflows KW - Ontologies KW - Digitalization PY - 2025 AN - OPUS4-64043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schilling, Markus A1 - Marschall, Niklas A1 - Niebergall, Ute A1 - Wachtendorf, Volker A1 - Böhning, Martin T1 - Unveiling Effects of Biodiesel and Diesel on Environmental Stress Cracking of PE-HD N2 - The behavior of high‐density polyethylene with respect to resistance against environmental stress cracking (ESC) is usually regarded as an inherent material property being specific for respective types of PE‐HD and tested using standardized methods, conditions, and also standard testing liquids (usually aqueous surfactant solutions). On the other hand, for practical applications the ESC behavior of those polymeric materials, commonly used for pipes or containers, in contact with other liquids (e.g., fuels) is often of relevant interest, but for a reasonable assessment, where consistent benchmark data for a direct comparison are often missing, it is essential to determine the actually prevailing failure mode and classify it related to crack propagation or other mechanisms. Using the well‐established Full Notch Creep Test, which favorably allows for a detailed microscopic fracture surface analysis after failure, the behavior of two typical PE‐HD types for container applications is investigated in biodiesel and diesel and compared to a standard surfactant solution. This enables a clear identification of characteristic features of the interaction of biodiesel and diesel as sorptive fuels in contact with the polymer, revealing the complex interplay of sorption and plasticization as well as ESC inducing effects on PE‐HD, which could be clearly shown for both fuels. KW - Biodiesel KW - Confocal laser scanning microscopy (LSM) KW - Diesel KW - Full notch creep test (FNCT) KW - Plasticization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650525 DO - https://doi.org/10.1002/pen.70239 SN - 0032-3888 SP - 1 EP - 16 PB - Wiley CY - Hoboken (NJ) AN - OPUS4-65052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Channammagari, Harichandana A1 - Sahr, Rabea A1 - Trappe, Volker T1 - Experimentelle, Analytisch-Numerische Untersuchung des thermischen Ausdehnungsverhaltens von Faser-Kunststoff-Verbunden N2 - Im Rahmen des Forschungsvorhabens PROVING wurde eine Methode zur rechnerischen Bestimmung thermomechanischer Eigenspannungen in CFK entwickelt. Ziel ist die Berücksichtigung des thermischen Ausdehnungsverhaltens bei der Bestimmung des dreidimensionalen in-situ-Spannungszustands der Matrix für den strukturellen Nachweis. Die Eigenspannungen werden über mikromechanische Modellierung und FEM berechnet; die zugrunde liegenden Ausdehnungsfunktionen wurden experimentell validiert. N2 - As part of the PROVING research project, a method for calculating thermomechanical residual stresses in CFRP was developed. The aim is to take thermal expansion behavior into account when determining the three-dimensional in-situ stress state of the matrix for structural verification. The residual stresses are calculated using micromechanical modeling and FEM; the underlying expansion functions have been experimentally validated. T2 - 43. Vortrags- und Diskussionstagung Werkstoffprüfung 2025 CY - Dresden, Germany DA - 27.11.2025 KW - Thermische Eigenspannungen KW - Mikromechanik KW - Faser-Kunststoff-Verbunde KW - FEM PY - 2025 SN - 978-3-88355-454-9 VL - 2025 SP - 154 EP - 159 PB - DGM CY - Sankt Augustin AN - OPUS4-65112 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sahr, Rabea T1 - Experimentelle, Analytisch-Numerische Untersuchung des Thermischen Ausdehnungsverhaltens von Faser-Kunststoff-Verbunden N2 - Im Rahmen des Forschungsvorhabens PROVING wurde eine Methode zur rechnerischen Bestimmung thermomechanischer Eigenspannungen in CFK entwickelt. Ziel ist die Berücksichtigung des thermischen Ausdehnungsverhaltens bei der Bestimmung des dreidimensionalen in-situ-Spannungszustands der Matrix für den strukturellen Nachweis. Die Eigenspannungen werden über mikromechanische Modellierung und FEM berechnet; die zugrunde liegenden Ausdehnungsfunktionen wurden experimentell validiert. T2 - 43. Vortrags- und Diskussionstagung Werkstoffprüfung 2025 CY - Dresden, Germany DA - 27.11.2025 KW - Thermische Eigenspannungen KW - Mikromechanik KW - Faser-Kunststoff-Verbunde KW - FEM PY - 2025 AN - OPUS4-65118 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Waurischk, Tina A1 - Deubener, J. A1 - Müller, Ralf T1 - Internal friction and energy dissipation during fracture in silicate glasses N2 - To obtain a deeper insight into the nature of energy dissipation during fracture, the internal friction of 13 borosilicate, aluminosilicate, soda-lime, and lead-containing glasses, for which inert crack growth data are known, was measured using dynamic mechanical thermal analysis. For asymmetrically bent glass beams, the loss tangent, tan δ, was determined between 0.2 and 50 Hz at temperatures between 273 K and the glass transition temperature, Tg. It was found that the area under the tan δ vs T·Tg−1 curve correlates with the crack growth exponent, n, in the empirical v = v0·KIn relation between crack growth velocity, v, and stress intensity, KI, which indicates that n correlates with the degree of energy dissipation of sub-Tg relaxation phenomena. KW - Glass KW - Internal friction KW - Crack growth PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651371 DO - https://doi.org/10.1063/5.0255432 SN - 0021-9606 VL - 162 IS - 19 SP - 1 EP - 9 PB - AIP Publishing AN - OPUS4-65137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pan, Z. A1 - Waurischk, Tina A1 - Duval, A. A1 - Müller, Ralf A1 - Deubener, J. A1 - Krishnan, N. M. A. A1 - Wondraczek, K. A1 - Wondraczek, L. T1 - Precise Real‐Time Measurement of Liquid Viscosity Using Digital Video Data N2 - Quantitative knowledge of liquid viscosity is of fundamental importance in many areas of materials synthesis and processing. However, the determination of viscosity often relies on specialized experimental equipment, offline experimentation, or invasive procedures, in particular when required in extreme conditions such as at high temperature, high pressure, and in confined or corrosive environments. Here, this study proposes and validates a fast and simple method that mimics the intuitive perception of liquid flow within a quantitative framework. For this, this study employs digital video observation to derive quantitative values of the shear viscosity of liquids, with high precision and rapid acquisition rates. The technique involves capturing liquid dynamics after minor mechanical stimulation. Processed imaging data are indexed by similarity and referenced to a digital database generated with a finite element model, from which values of viscosity are obtained in line. The approach is tested on water at room temperature and on a high‐temperature glass melt. Covering a viscosity range of four orders of magnitude, both yield convincing agreement with tabulated reference data at low computational cost. KW - Glass KW - Liquid Viscosity KW - Digital Video Data KW - Finite Element Method PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651363 DO - https://doi.org/10.1002/aisy.202500297 SN - 2640-4567 VL - 7 IS - 12 SP - 1 EP - 12 PB - Wiley VHC-Verlag AN - OPUS4-65136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Channammagari, Harichandana T1 - From Micromechanics to Macro Validation: A New Approach for Aerospace Structures N2 - Given the high experimental effort required to verify fiber‑reinforced polymer composites (FRP) in aviation, the PROVING project (Production, Optimization, and Virtual Verification for Generative Manufacturing Processes) aims to establish a streamlined and robust verification methodology based on analytical and numerical approaches. As a foundation for this virtual verification process, BAM contributed extensive material testing for parameter identification, feeding directly into the material models and probabilistic methods. Beyond the experiments, an analytical‑numerical model was developed to more accurately determine the in‑situ stress state within the composite matrix. Since damage initiation in FRP is largely driven by inter-fiber failure, the three‑dimensional matrix stress state is essential for structural verification. In addition to external loading, thermomechanical residual stresses arising from the mismatched thermal expansion of fibers and matrix contribute to the stress state. Within PROVING, a calculation method was developed that incorporates the thermomechanical behavior of carbon‑fiber‑reinforced polymers (CFRP) into the verification process with minimal experimental effort. The method determines matrix thermal residual stresses using micromechanical modeling combined with finite element analysis. T2 - 29. Nationales SAMPE Symposium CY - Aachen, Germany DA - 02.04.2025 KW - Virtual Verification KW - Micromechanics KW - FEA PY - 2025 AN - OPUS4-65187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Santos Baltieri, Ricardo T1 - Luminescence Thermometry in Pure TeO₂ Glasses Doped with Er3+/Yb3+ and Eu3+: Remote Sensing Capability Across the Biological Temperature Range N2 - The development of non-contact and remote temperature sensors based on rare-earth (RE3+)-doped glasses is crucial for emerging applications in biomedical diagnostics and microscale thermal monitoring. In this study, we explore the fundamental thermometric properties of pure tellurite (TeO2) glasses doped with either Er3+/Yb3+ or Eu3+ ions in a wide range of temperature. The Er3+/Yb3+-co-doped system was analyzed through upconversion emission thermometry, particularly involving thermally coupled levels 2H11/2 and 4S3/2. The intensity ratio between these levels exhibits a clear temperature dependence from 100 K to 530 K, with an inversion near 160 K and optimal sensitivity above 250 K. At 300 K, the relative sensitivity (SR) reached 1.1% K−1, and the absolute sensitivity peaked at 6.5 × 10−3 K−1 at 460 K. Figure on the left is the Er3+ upconversion luminescence dependency on temperature, in the center is the excitation spectra of Eu3+ with temperature, and on the right is the comparison between calculated and measured temperature for Eu3+ samples. In parallel, the excitation spectra of Eu3+-doped TeO2 glasses were acquired from 100 K to 520 K, revealing three thermally responsive spectral regions. These transitions exhibited temperature-dependent intensity inversions, enabling the use of excitation-based thermometry. Notably, one of the regions provided the most accurate temperature predictions, with a relative sensitivity of 0.5% K−1 at 300 K. Both systems benefit from the high optical transparency, chemical stability, and low phonon energy of pure TeO2 glass, making them ideal candidates for remote sensing platforms, such as fiber-optic tips or implantable probes. While the Er3+/Yb3+ system provides robust upconversion emission for conventional thermometry, the Eu3+ system introduces an innovative excitation-based strategy, broadening the applicability of RE3+-doped tellurite glasses for optical thermometry. Acknowledgements This work was supported by the São Paulo Research Foundation (FAPESP – N. 2020/11038-2, 2023/05994-6, 2024/04675-7) and National Council for Scientific and Technological Development (CNPq - 304718/2023-8). T2 - Shift 2025 Conference CY - Tenerife, Spain DA - 13.10.2025 KW - Lanthanide KW - Optical thermometry KW - Energy conversion PY - 2025 AN - OPUS4-65195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Elfetni, Seif A1 - Darvishi Kamachali, Reza T1 - PINNs-MPF: A Physics-Informed Neural Network framework for Multi-Phase-Field simulation of interface dynamics N2 - We present PINNs-MPF framework, an application of Physics-Informed Neural Networks (PINNs) to handle Multi-Phase-Field (MPF) simulations of microstructure evolution. A combination of optimization techniques within PINNs and in direct relation to MPF method are extended and adapted. The numerical resolution is realized through a multi-variable time-series problem by using fully discrete resolution. Within each interval, space, time, and phases/grains are treated separately, constituting discrete subdomains. PINNs-MPF is equipped with an extended multi-networking (parallelization) concept to subdivide the simulation domain into multiple batches, with each batch associated with an independent NN trained to predict the solution. To ensure continuity across the spatio-temporal-phasic subdomains, a Master NN efficiently is to handle interactions among the multiple networks and facilitates the transfer of learning. A pyramidal training approach is proposed to the PINN community as a dual-impact method: to facilitate the initialization of training when dealing with multiple networks, and to unify the solution through an extended transfer of learning. Furthermore, a comprehensive approach is adopted to specifically focus the attention on the interfacial regions through a dynamic meshing process, significantly simplifying the tuning of hyper-parameters, serving as a key concept for addressing MPF problems using machine learning. We perform a set of systematic simulations that benchmark foundational aspects of MPF simulations, i.e., the curvature-driven dynamics of a diffuse interface, in the presence and absence of an external driving force, and the evolution and equilibrium of a triple junction. The proposed PINNs-MPF framework successfully reproduces benchmark tests with high fidelity and Mean Squared Error (MSE) loss values ranging from 10^−6 to 10^−4 compared to ground truth solutions. KW - Machine learning KW - PINNs KW - Phase-field method KW - Microstructure evolution KW - Parallel training KW - Neural networks PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629740 DO - https://doi.org/10.1016/j.enganabound.2025.106200 SN - 0955-7997 VL - 176 SP - 1 EP - 22 PB - Elsevier CY - Amsterdam AN - OPUS4-62974 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Elfetni, Seifallah A1 - Darvishi Kamachali, Reza T1 - PINNs-MPF: An Efficient Physics-Informed Machine Learning-based Solver for Multi-Phase-Field Simulations using Tensorflow N2 - This paper introduces PINNs-MPF, a novel Machine Learning-based solver designed for Multi-Phase-Field (MPF) and diffuse interface simulations, offering innovative approaches to address complex challenges in addressing microstructure evolution in polycrystalline materials using Machine Learning. The framework not only surpasses current limitations in handling multi-phase problems but also allows for potential upscaling to tackle more intricate scenarios. Developed in Python, the related code leverages optimized libraries like TensorFlow, showcasing efficiency and potential scalability in materials science and engineering simulations. This framework, integrating advanced techniques such as multi-networking and training optimization, setting a new standard in predictive capabilities and understanding complex physical phenomena. KW - Machine Learning KW - Microstructure Simulation KW - Phase Field PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631917 DO - https://doi.org/10.1016/j.simpa.2025.100753 SN - 2665-9638 VL - 24 SP - 1 EP - 4 PB - Elsevier B.V. AN - OPUS4-63191 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leo, Reinhold T1 - Duplex stainless steels - Compatibility for high-pressure hydrogen applications N2 - Duplex Stainless Steels (DSS) are an essential component used in the construction of transportation pipelines because of their many distinctive qualities. The choice of DSS for a particular hydrogen application mainly depends on its susceptibility level to Hydrogen Assisted Cracking (HAC). Several mechanisms have been proposed to describe the occurring microscale processes behind HAC, and these include metastable phase transformation, Hydrogen Enhanced Localized Plasticity (HELP), and Hydrogen Enhanced Decohesion (HEDE). This contribution describes the path to ascertain if DSS is suitable for high-pressure gaseous hydrogen applications. The interplay between several critical factors that result in HAC was examined using high-pressure gaseous hydrogen charging, Electron Backscatter Diffraction (EBSD), tensile testing and hydrogen concentration measurements using Carrier Gas Hot Extraction (CGHE). T2 - Third German-African Green Hydrogen Forum 2025 CY - Bernburg (Saale), Germany DA - 23.09.2025 KW - Hydrogen Assisted Cracking KW - High Pressure Hydrogen KW - Duplex Stainless Steels KW - Hollow Specimen Technique PY - 2025 AN - OPUS4-64302 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Murugan, Jegatheesan A1 - Darvishi Kamachali, Reza T1 - High‑throughput investigation of grain boundary segregation landscape in the Fe–Ni–Cr system N2 - Understanding phase stability in multicomponent alloy systems, particularly at internal interfaces, remains a major challenge in materials science. Grain boundary (co-)segregation is a critical factor influencing interfacial stability, often leading to microstructural degradation and safety concerns. In this study, we investigate segregation behavior in the face-centered cubic (FCC) Fe–Ni–Cr alloy system, a foundational system for many steels, superalloys, and high-entropy alloys. CALPHAD-integrated density-based phase-field model is extended to compute the segregation of Fe, Ni, and Cr at grain boundaries as a function of the bulk composition, with the relative GB density serving as a key parameter representing grain boundary character. A high-throughput computational screening is performed across the stable compositional space at 723 K, 1023 K, and 1323 K. The results reveal a rich and temperature-sensitive segregation landscape, with element-specific enrichment and depletion patterns that vary with alloy composition. Notably, opposite segregation trends between Ni and Cr, and frequent co-segregation of Fe and Ni, are observed at lower temperatures. The developed framework captures the coupled effects of temperature, chemical interactions, grain boundary structure, and enthalpy-entropy compensation on segregation and GB phase stability. The origin and implications of these phenomena are discussed in terms of the underlying thermodynamic driving forces. KW - Segregation Engineering KW - Grain boundary segregation KW - Thermodynamics KW - CALPHAD KW - Fe--Ni--Cr alloys PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646404 DO - https://doi.org/10.1007/s10853-025-11717-5 SN - 1573-4803 SP - 1 EP - 21 PB - Springer Science + Business Media CY - Dordrecht [u.a.] AN - OPUS4-64640 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meira, Maria Fernanda Cavalcante A1 - Fernandes, Gabriela Leal Peres A1 - de Camargo, Andréa Simone Stucchi A1 - Ravaro, Leandro Piaggi A1 - Arai, Marylyn Setsuko A1 - Navarro, Maria Fidela de Lima A1 - Brighenti, Fernanda Lourenção A1 - Oliveira, Analú Barros de A1 - Danelon, Marcelle ED - Stucchi de Camargo, Andrea T1 - Modification of restorative glass ionomer cement with zinc oxide nanoparticles and calcium glycerophosphate microparticles: in vitro assessment of mechanical properties and antimicrobial activity N2 - Abstract The incorporation of bioactive agents into resin-modified glass ionomer cement (RMGIC) is a promising strategy to improve its mechanical strength and biofilm control, especially for patients with active dental caries. Objective This study aimed to evaluate the effects of incorporating ZnONPs and CaGP into RMGIC on its mechanical and microbiological properties. Design Six groups were tested: 1) RMGIC (without CaGP/ZnONPs); 2) RMGIC-1.0%ZnONPs; 3) RMGIC-2.0%ZnONPs; 4) RMGIC-3.0%CaGP; 5) RMGIC-3.0%CaGP-1.0%ZnONPs; and 6) RMGIC-3.0%CaGP-2.0%ZnONPs. The compressive strength (CS), diametral tensile strength (DTS), and surface hardness (SH) were evaluated after 24 hours and 7 days. Antimicrobial and antibiofilm activity were evaluated using agar diffusion and biofilm metabolic activity (XTT) assays. Results After 24 hours, all the groups showed similar DTS values (p0.05), except for RMGIC-3.0%CaGP-1.0%ZnONPs, which showed the highest DTS value (p<0.05). Comparing 24 hours and 7 days, the DTS values of RMGIC-3.0%CaGP-2.0%ZnONPs, RMGIC-3.0%CaGP, and RMGIC-3.0%CaGP-2.0%ZnONPs were similar (p=0.360). After 24 hours, the RMGIC group showed the CS highest value, followed by RMGIC-2.0%ZnONPs (p < 0.05). After 7 days, the RMGIC-3.0%CaGP-1.0%ZnONPs group exhibited the highest CS value, approximately 15% higher than RMGIC (p<0.05). The RMGIC-1.0%ZnONPs group exhibited significantly higher SH at 24 hours (p=0.621). At 7 days, the highest SH value was observed for the RMGIC-3.0%CaGP-1.0%ZnONPs group (p<0.05). Regarding antimicrobial and antibiofilm activity, including results from biofilm metabolism assays, the RMGIC-3.0%CaGP-1.0%ZnONPs group demonstrated the most effective antimicrobial and inhibitory effects (p<0.05). Conclusion This study demonstrated that adding ZnONPs and CaGP to RMGIC enhanced its mechanical and antimicrobial and antibiofilm properties, suggesting enhanced mechanical performance and improved protection against cariogenic biofilms—critical factors for successful restorative treatments. Therefore, the addition of ZnONPs and CaGP is a promising strategy to develop advanced restorative materials that improve clinical outcomes, especially for patients with active dental caries. KW - Resin-modified glass ionomer cement KW - Phosphate KW - Zinc oxide nanoparticles KW - Biofilm KW - Mechanical properties PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652799 DO - https://doi.org/10.1590/1678-7757-2025-0356 SN - 1678-7765 VL - 33 SP - 1 EP - 14 PB - FapUNIFESP (SciELO) AN - OPUS4-65279 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arai, Marylyn S. A1 - Brambilla, Gabriel V. A1 - Corrêa, Bruna Carolina A1 - Merízio, Leonnam G. A1 - Inada, Natalia M. A1 - de Camargo, Andrea S. S. T1 - A Dual-Mode “Turn-On” Ratiometric Luminescent Sensor Based on Upconverting Nanoparticles for Detection and Differentiation of Gram-Positive and Gram-Negative Bacteria N2 - Infectious bacterial diseases, intensified by antibiotic resistance, cause millions of deaths annually and pose risks beyond human health, including water and food contamination. Current diagnostics are often slow, require complex equipment, and lack specificity, highlighting the need for rapid and reliable detection methods. To address this, we developed a luminescent sensor based on NaYF4 upconverting nanoparticles (UCNPs) doped with Er3+ or Tm3+, coated with COOH-PEG4-COOH, and functionalized with vancomycin (Van) or polymyxin-B (Poly) to selectively target Gram-positive and Gram-negative bacteria, respectively. Gold nanoparticles (AuNPs) served as quenchers, enabling a ratiometric “turn-on” mechanism: upon bacterial binding, the UCNP emission, initially quenched by AuNPs, was partially restored. This allowed Differentiation through changes in the green/red (G/R) ratio for Er-UCNP@PEG4-Van and the blue/red (B/R) ratio for Tm-UCNP@PEG4-Poly. The sensor distinguished between Gram-positive and Gram-negative bacteria over a wide concentration range (0.05 to 5 × 105 CFU/mL) and showed high correlation with actual bacterial counts (r = 0.99 for S. aureus, r = 0.91 for E. coli). This platform is a potential fast, selective, and reliable tool for bacterial detection in clinical and environmental settings. KW - Lminescent sensor KW - Upconverting nanoparticles KW - Gram-positive and Gram-negative bacteria KW - Ratiometric luminescent sensors PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652785 DO - https://doi.org/10.1021/acsomega.5c07006 SN - 2470-1343 VL - 10 IS - 39 SP - 46040 EP - 46050 PB - American Chemical Society (ACS) AN - OPUS4-65278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Marschall, Niklas A1 - Murugan, Jegatheesan A1 - Darvishi Kamachali, Reza T1 - Incorporating elasticity into the thermodynamics and phase diagrams of multi-component systems N2 - Elastic energy plays a critical role in determining phase stability in compositionally complex alloys. However, quantifying elastic contributions in multi-component systems and incorporating them into phase diagram construction remain challenging. In this study, we present a generalized elastic energy formalism tailored for multi-component alloys, which can be directly and efficiently integrated with CALPHAD thermodynamic databases and existing frameworks such as Thermo-Calc (Andersson et al., 2002), Pandat (Cao et al., 2009) or FactSage (Bale et al., 2016). This elasticity formalism can also be introduced as a post-processing layer in open-source software such as pyCALPHAD (Otis and Liu, 2017) and Kawin (Ury et al., 2023) , enabling elastic assessments in multi-component systems. We apply our framework for constructing the phase diagram of quinary Fe–Mn–Ni–Co–Cu alloy system, utilizing convex hull and Hessian matrix under elastic considerations. Our results reveal that incorporating elastic energy leads to an expansion of both the spinodal region and the miscibility gap. These are governed by the intricate interplay of chemical and elastic driving forces: We found that Mn and Ni contribute strongly to chemical stabilization, while Cu and Co tend to destabilize the alloy, especially at low Mn concentrations. The stabilizing effect of Fe is also pronounced in Mn-deficient regions. Acting as a destabilizing factor, the elastic energy is primarily driven by the presence of Mn, underscoring its multifaceted role in thermodynamic stability. In Mn-rich compositions, Cu markedly reduces the elastic energy contribution. Combined with CALPHAD infrastructures, the current framework offers a practical pathway to improve the predictive accuracy of phase stability and transformations in complex multi-component alloys. KW - Elastic energy KW - HEA KW - CALPHAD KW - Elastic spinodal KW - Elastic miscibility gap KW - Elastic phase diagram PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643339 DO - https://doi.org/10.1016/j.mtla.2025.102546 SN - 2589-1529 VL - 44 SP - 1 EP - 18 PB - Elsevier CY - Amsterdam, Niederlande AN - OPUS4-64333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arai, Marylyn Setsuko A1 - Machado, Thales Rafael A1 - da Silva, Beatriz Giacomelli Rodrigues A1 - Vilela, Raquel Riciati do Couto A1 - de Camargo, Andrea Simone Stucchi A1 - Zucolotto, Valtencir T1 - Biomimetic Upconverting Nanoplatforms for Glioblastoma Bioimaging and Targeted Therapy N2 - Infectious bacterial diseases, intensified by antibiotic resistance, cause millions of deaths annually and pose risks beyond human health, including water and food contamination. Current diagnostics are often slow, require complex equipment, and lack specificity, highlighting the need for rapid and reliable detection methods. To address this, we developed a luminescent sensor based on NaYF4 upconverting nanoparticles (UCNPs) doped with Er3+ or Tm3+, coated with COOH-PEG4-COOH, and functionalized with vancomycin (Van) or polymyxin-B (Poly) to selectively target Gram-positive and Gram-negative bacteria, respectively. Gold nanoparticles (AuNPs) served as quenchers, enabling a ratiometric “turn-on” mechanism: upon bacterial binding, the UCNP emission, initially quenched by AuNPs, was partially restored. This allowed differentiation through changes in the green/red (G/R) ratio for Er-UCNP@PEG4-Van and the blue/red (B/R) ratio for Tm-UCNP@PEG4-Poly. The sensor distinguished between Gram-positive and Gram-negative bacteria over a wide concentration range (0.05 to 5 × 105 CFU/mL) and showed high correlation with actual bacterial counts (r = 0.99 for S. aureus, r = 0.91 for E. coli). This platform is a potential fast, selective, and reliable tool for bacterial detection in clinical and environmental settings. KW - Glioblastoma KW - Homotypic targeting KW - Cell membrane coating KW - Upconverting nanoparticles KW - Temozolamide KW - Near infrared bioimaging KW - Drug delivery PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652808 DO - https://doi.org/10.1021/acsanm.5c04567 SN - 2574-0970 VL - 10 IS - 39 SP - 1 EP - 13 PB - American Chemical Society (ACS) AN - OPUS4-65280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea A1 - Arai, Marylyn Setsuko T1 - Upconversion nanoparticles for chemical, physical and biological sensing: from functionalization to point-of-care devices N2 - Among several applications, versatile upconversion nanoparticles (UCNPs) which can convert lower-energy infrared radiation into higher-energy visible or ultraviolet light, have emerged as one of the most powerful tools in the field of chemical, physical and biological sensing. The use of UCNPs in fluorescent sensors allows non-invasive, highly sensitive, and selective detection methods, which are particularly beneficial in environments requiring minimal interference and high precision for analytes that can range from metal ions to biomolecules. In this lecture, an overview and the state of the art will be given, accompanied by examples of our recent contributions to key areas such as chronic disease diagnostics, bacterial sensing, and multifunctionally responsive nanoplatforms: (1) An Enhanced Luminescence Lateral-Flow Assay (ELLA) designed for rapid (< 15 min) and early detection of acute kidney injury biomarkers in urine samples, using a commercial cell phone camera, will be presented. The platform is based on Er³⁺- and Tm³⁺-doped UCNPs whose emissions intensities are 40-fold enhanced by an Au-coated mesoporous silica shell, enabling the accurate detection of KIM-1 and NGAL biomarkers with detection limits as low as 0.23 ng/mL; (2) Also, a multifunctional nanoplatform that combines Tm³⁺-doped UCNPs with a Cu(I) complex for applications in oxygen sensing, optical thermometry, and emission colour tuning will be presented. The platform utilizes Luminescent Resonance Energy Transfer (LRET) to achieve efficient energy transfer, enabling red emission from the Cu(I) complex while allowing the use of the UCNP’s original emissions for thermometry. The dual functionality allows sensitive O2 detection and temperature measurements, with relative sensitivities of up to 1% K⁻¹; (3) The critical challenge of rapid bacterial detection and differentiation was addressed by the development of a novel UCNP-based sensor. By functionalizing UCNPs with the antibiotics - vancomycin for Gram-(+) and polymyxin-B for Gram-(-), and using Au nanoparticles as intensity quenchers, the sensor leverages a ratiometric "turn-on" mechanism for selective detection of the bacteria, through changes in the green/red (G/R) ratio for Er-UCNP@PEG4-Van, and blue/red (B/R) ratio for Tm-UCNP@PEG4-Poly. By this approach, differentiation was possible over a wide concentration range of bacteria (0.05 to 5 x 105 CFU/mL) with high correlation with actual bacterial counts (r = 0.99 for S. aureus, r = 0.91 for E. coli); (4) Recently, we have demonstrated a water dispersable ratiometric pH-nanosensor based on host-guest interaction of Tm3+/Yb3+ co-doped UCNPs functionalized with b-cyclodextrin (b-CD) and a pH-responsive nitrobenzoxadiazol dye modified with adamantane (NBD-Ad). The sensor shows a ratiometric emission response (blue/red) over a pH range of 8.0 – 11.0 with high reproducibility, excellent reusability and selectivity, even in the presence of interferents. Together, the presented examples highlight the versatility and potential of UCNPs to develop novel sensors, offering measurable advances in diagnostics, environmental monitoring, and beyond. T2 - Shift2025 - Spectral shaping for biomedical and energy applications CY - Tenerife, Spain DA - 13.10.2025 KW - Upconverting nanoparticles KW - Fluorescent sensors KW - Point-of-care devices PY - 2025 AN - OPUS4-65282 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea T1 - Enhanced emission of Nd3+ by localized silver nanocluster growth via direct laser writing in Ga-fluoride phosphate glasses N2 - Gallium fluoride phosphate glasses are promising materials for optical applications in the visible to near infrared spectra due to their wide transmission window and ability to accommodate optically active dopants. In this study, melt quenched glasses in the compositional system 25Ga(PO₃)₃–20ZnF₂–30BaF₂–(25–x–y)SrF₂–xAgNO₃–yNdF₃ (x = 0 -10 mol%, y = 0 or 1 mol%) were studied and fully characterized by conventional and spectroscopic techniques to understand the interaction of silver species and Nd³⁺ ions. In Ag+ doped samples, the observation of a broad emission band in the visible spectrum evidences the overlapping presence of Ag⁺, Ag nanoclusters (NCs), and [Ag₂]²⁺ species. In the sample doped with 10 mol% Ag⁺, the development of a dark yellow color and alterations in the emission profile suggest the formation of Ag nanoparticles. In an attempt to control and increase the formation of Ag nanoclusters in a localized way, the glasses with 3 and 5 mol% Ag+ were subjected to direct laser writing (DLW) with femtosecond laser pulses at variable inscription intensities and scan speeds. As expected, the approach led to localized growth of Ag-NCs with precise spatial control and as a consequence, the Nd³⁺ emissions in the NIR region (e.g. at1060 nm) were significantly enhanced in laser-structured regions as compared to unmodified areas, evidencing efficient energy transfer from silver species to Nd³⁺ ions. These results demonstrate that DLW, applied for the first time in these glasses, enables precise spatial control over silver nanocluster formation, offering a viable route to process optical glasses for photonic applications. T2 - XXIII - B-MRS Meeting CY - Salvador, Brazil DA - 28.09.2025 KW - Fluoride phosphate glasses KW - Direct laser writting KW - Neodymium KW - Silver nanoclusters PY - 2025 AN - OPUS4-65281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shasmal, Nilanjana T1 - Effects of Direct femtosecond laser writing on chloroborosilicate glasses doped with Eu3+/Eu2+ and CdS quantum dots N2 - Femtosecond (fs) direct laser writing (DLW) is a promising technique for developing nano-inhomogeneous materials with advanced optical properties and for fabricating novel photonic devices such as integrated waveguides, ultrafast optical switches, phase plates, and 3D optical memory. In this study, DLW was applied to chloroborosilicate glasses that were singly and co-doped with Eu and CdS quantum dots (QDs). The glasses were laser-treated within a very narrow range of experimental conditions, resulting in laser-inscribed sites exhibiting enhanced emission, similar to the glass-ceramics crystallized from the as-prepared glass. In the regions crystalized by DLW a significant reduction of Eu3+ to Eu2+ was verified by photoluminescence spectroscopy. However, the characteristics of the emission bands of Eu2+ changed markedly in the laser-treated sites as compared to the emission spectra of the same glass crystallized by heat treatment. A considerable redshift and splitting of the emission band were observed, attributed to changes in the surrounding environment of the rare earth (RE) ions which was, in turn, attributed to an alteration in the coordination number of Ba2 + and/or Eu2+ as a result of the high-power laser treatment. Although there was an issue with homogeneity of the glass in the micro-level, which restricts some of the aspects of the DLW, these findings suggest the potential for structural modifications through laser treatment, which could be harnessed to create new functionalities for advanced optical applications. T2 - ICG 2025 (27th International Congress on Glass) CY - Kolkata, India DA - 20.01.2025 KW - Femtosecond direct laser writing KW - DLW KW - CdS quantum dots KW - Eu/CdS co-doped glass PY - 2025 AN - OPUS4-65285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonrado T1 - Low-Cycle Fatigue Behavior of Laser Powder Bed Fused Inconel 718 at Room and High Temperature N2 - The nickel-base superalloy Inconel 718 (IN718) is one of the most commonly used Ni-based superalloys for high temperature structural applications for its remarkable strength, as well as creep, fatigue, and corrosion resistance up to 650 °C. While IN718 has traditionally been employed as cast or wrought material, it is difficult to machine because of its high strength and toughness. The additive manufacturing of IN718 components made by metal AM has thus gained extensive attention to produce expensive near-net shaped components of high-temperature alloys such as IN718, for it saves material and costs in processing and machining steps. Among all metal additive manufacturing (AM) technologies, laser powder bed fusion (PBF-LB/M) is the most widespread, IN718 being one of the most common alloys produced with it. However, high cooling rates associated to the PBF-LB/M process, hinders the primary strengthening phases γ’’ and γ’ to form, as these cooling rates induce a dislocation cellular substructure, at which walls primary Laves phases bind segregating Nb, Ti and Mo. Many of the therefore needed heat-treatment strategies can then promote Laves-phase transformation into the stable δ phase along the cell and grain boundaries. Laves and δ phases, as well as grain-boundary primary carbides may have adverse effects on mechanical properties. The mostly needle-shaped δ phase was namely found to have a detrimental effect on creep rupture life while no direct effect on LCF fatigue life was evident. In this work room- and high-temperature (650 °C) low-cycle fatigue behavior of PBF-LB/M IN718 is investigated in the four-step heat-treated state and compared to wrought IN718. The microstructure of both materials is characterized across length scales via microscopy methods. The fatigue life at room temperature of the PBF-LB/M IN718 material is slightly lower than that for the wrought material, which is reversed at 650 °C. The cyclic stress response for both materials is marked by cyclic softening that is more pronounced at higher test temperatures. Multiple secondary cracks form at high strain amplitudes, at both room and high temperatures. High testing temperatures enhance specially crack formation at the transitions of regions between elongated grains and columns of stacked grains with ripple patterns in the PBF-LB/M material. Additional to this behavior, pronounced crack branching and deflection indicate that the cracks are controlled by sharp micromechanical gradients. T2 - EUROMAT 2025 CY - Granada, Spain DA - 14.09.2025 KW - Additive manufacturing KW - Low-cycle fatigue KW - Microstructural characterization KW - Ni-base superalloy PY - 2025 AN - OPUS4-64354 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ávila Calderón, Luis A1 - Han, Ying A1 - Matzak, Kathrin A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit T1 - NFDI-MatWerk/IUC02 data schema for elevated temperature tensile data of Ni-based superalloys N2 - Strength characteristics, such as proof strength and tensile strength, of metallic materials are usually measured at room temperature. However, for high-temperature materials, the values at operational temperatures are equally important for analyzing the mechanical behavior of components or for designing purposes. Elevated temperature tensile tests (often referred to as hot tensile tests) generally enable the measurement of the same material parameters as those obtained at room temperature. Typically, tensile and proof strength, elongation after fracture, and reduction of area are analyzed, with the focus often being on proof strength. The attached data schema for elevated temperature tensile tests was developed within the German NFDI-MatWerk initiative (https://nfdi-matwerk.de/). It builds on a previously published creep data schema and follows a reference data methodology that has also been previously outlined. The presented schema constitutes a structured approach for collecting all relevant information on an elevated temperature tensile test experiment. Overall, this development, as defined in the previously published data schema for creep data, aims to provide a comprehensive hierarchical data description that can be implemented in data management platforms (such as electronic laboratory notebooks), facilitate consistent quality assessment across different users and data providers, and promote the alignment of datasets to the FAIR principles by providing easy interoperability and full reusability. The presented schema was initially developed for datasets of Ni-based high-temperature alloys. However, thanks to its modular structure, it can also be applied to tensile tests of various metallic and other materials. Although the focus is on elevated temperature tensile testing, the data schema also offers a solid foundation for documenting room temperature tensile tests. In such cases, an adjustment of the requirement profile might be necessary, and categories or entries specific to mechanical testing at elevated temperatures, such as “temperature-measuring system”, “specified temperature”, or “soaking time”, become irrelevant. Overall, a detailed approach was followed to ensure the collection of all relevant information, including both metadata and test results. This includes, for example, comprehensive descriptions of the material’s manufacturing history and of the laboratory equipment, and basic strength and deformation characteristic values. The resulting data schema aims to support the description and identification of high-quality datasets, which may qualify as reference data of materials. Our current definition of reference data of materials has been published elsewhere. It should be noted, however, that not all research datasets —depending on their origin and purpose— require this full level of detail. Nevertheless, the presented data schema can support data providers in evaluating the completeness and value of their datasets. This version of the data schema covers elevated temperature tensile tests on both single- and polycrystalline specimen materials. The terminology is aligned with DIN EN ISO 6892-1 and DIN EN ISO 6892-2. It is designed to record the use of temperature measurement using thermocouples and the use of contacting extensometer systems. The requirement profile refers to the highest quality class of reference data, taken from calibrated instruments, and which shall enable the following usages: 1. Checking one's own elevated temperature tensile test results on nominally similar material 2. Verification of own testing set-up (e.g., by testing the same or a similar material) 3. Using the data as input data for simulations in the context of design or alloy development KW - NFDI MatWerk KW - Referenzdaten KW - Zugversuch KW - CMSX-6 KW - Datenschema KW - NFDI MatWerk KW - CMSX-6 KW - Data schema KW - Reference data KW - Tensile test PY - 2025 UR - https://doi.org/10.5281/zenodo.17846436 DO - https://doi.org/10.5281/zenodo.17846435 PB - Zenodo CY - Geneva AN - OPUS4-65190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eisenbart, Miriam A1 - Hanke, Thomas A1 - Bauer, Felix A1 - Beygi Nasrabadi, Hossein A1 - Junghanns, Kurt A1 - Dziwis, Gordian A1 - Tikana, Ladji A1 - Parvez, Ashak Mahmud A1 - van den Boogaart, Karl Gerald A1 - Sajjad, Mohsin A1 - Friedmann, Valerie A1 - Preußner, Johannes A1 - Ramakrishnan, Anantha Narayanan A1 - Klengel, Sandy A1 - Meyer, Lars‐Peter A1 - Martin, Michael A1 - Klotz, Ulrich Ernst A1 - Skrotzki, Birgit A1 - Weber, Matthias T1 - KupferDigital: Ontology‐Based Digital Representation for the Copper Life Cycle N2 - The copper life cycle comprises numerous stages from the alloy production to the manufacturing and usage of engineered parts until recycling. At each step, valuable data are generated and stored; some are transferred to the subsequent stations. A thorough understanding of the materials’ behavior during manufacturing processes or throughout their product lifetime is highly dependent on a reliable data transfer. If, for example, a failure occurs during the service life, information about the manufacturing route can be of decisive importance for detecting the root cause of the failure. Additionally, the life cycle assessment hinges on the availability of data. Recording and storing interoperable structured data is, therefore, a thriving research field with huge implications for the economic strength of the manufacturing industry. In the KupferDigital project, it is demonstrated how an ontology‐based data space can be utilized not only as an innovative method for storing and providing interoperable life cycle data but also as a means to enable automated data analysis and evaluation, leading to new insights and the creation of new knowledge using semantic data and technologies. This work illustrates how data recorded at different research facilities can be integrated into one single data space, allowing queries across heterogeneous sources. KW - Copper Alloy KW - Ontology KW - Digitalization KW - Data Space KW - Semantic Representation PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630213 SN - 1527-2648 DO - https://doi.org/10.1002/adem.202401735 VL - 27 IS - 8 SP - 1 EP - 29 PB - Wiley AN - OPUS4-63021 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suarez Ocano, Patricia T1 - Influence of heat-treatment-induced microstructural evolution on the Low Cycle Fatigue behavior of 316L stainless steel fabricated by Laser Powder Bed Fusion N2 - Additive manufacturing, particularly the laser powder bed fusion (PBF-LB/M) process, has gained significant attention in recent years due to its ability to produce complex geometries with enhanced mechanical properties. Among the various materials used, 316L stainless steel is highly favored for cyclically loaded components due to its exceptional mechanical strength, high-temperature performance, and corrosion resistance, making it widely applicable across various industries. 316L SS fabricated by PBF-LB/M (PBF-LB/M/316L) exhibits a unique hierarchical microstructure, with high density of low-angle grain boundaries (LAGBs), nano-dispersed silicates, chemical micro-segregations, and solidification-induced cellular structures. Particularly, the submicron-sized cellular features enriched with chromium (Cr) and molybdenum (Mo), along with high dislocation densities, contribute to a superior strength-ductility balance compared to conventionally manufactured 316L SS. The dispersed silicate particles act also as a strengthening phase, impeding dislocation movement and enhancing plastic deformation resistance. This study explores the effect of heat treatments on the low-cycle fatigue (LCF) behavior of PBF-LB/M/316L at room temperature (RT) and 600 °C. First, three heat treatment conditions were applied to the as-built material: 450 °C for 4 hours (HT450/4), 800 °C for 3 hours (HT800/3), and 900 °C for 1 hour (HT900/1) to investigate their influence on microstructural evolution. Microstructural analysis revealed that the HT450/4 condition preserved the cellular structure with high dislocation density, while the HT800/3 condition showed partial dissolution of cells together with reduction in segregated elements along the cell walls and a reduced dislocation density. The HT900/1 condition resulted in complete segregation and cellular structure dissolution with comparable dislocation density to HT800/3 while maintaining the crystallographic texture and grain morphology. Intermetallic χ phase was mostly observed at the grain boundaries in HT800/3, but not in HT900/1. Fully reversed LCF tests were conducted under strain-controlled conditions with a strain amplitude of 0.8 %. Tests were interrupted at specific intervals to analyze the interaction between hierarchical microstructural features and deformation mechanisms in the three heat-treated conditions. Due to the pronounced dislocation cell structures and elemental segregation, the microstructure of the HT450/4 condition significantly impact deformation and damage mechanisms during cyclic loading, which in turn, differ from the conventional produced counterparts. The results provide insights into the relationship between microstructural features and fatigue performance, highlighting key deformation and failure mechanisms under cyclic loading. T2 - FEMS 2025 EUROMAT 18th European Congress and Exhibition on Advanced Materials and Processes CY - Granada, Spain DA - 14.09.2025 KW - Additive manufacturing KW - 316L stainless steel KW - Heat treatments KW - Low Cycle Fatigue KW - Microstructure PY - 2025 AN - OPUS4-64238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Jentzsch, Stefan A1 - Stock, Daniel A1 - Häcker, Ralf A1 - Skrotzki, Birgit A1 - Darvishi Kamachali, Reza A1 - Klingbeil, Dietmar A1 - Kindrachuk, Vitaliy T1 - Split Hopkinson Pressure Bar (SHPB) investigations of steel S355 specimens and complementary characterization methods N2 - The workbook SHPB_S355.xlsx contains in the main spreadsheet S355_TestOverview an overview on the S355 specimens, which were tested in Split Hopkinson Pressure Bar (SHPB) and complementary quasi-static (QS) tests. The tests were conducted with notched hat-shaped specimens without a notch offset (S355_TestOverview/column geometry: “no offset”) and a small notch offset of x=0.35 mm (S355_TestOverview/column geometry: “offset”), cf. Fig. 1 [1]. Furthermore, for selected specimens, links are provided to DIC and bar strain measurement files as well as to evaluations from further characterization methods (microhardness, EBSD). For the boundary conditions at the SHPB projectile impact, the pressures of the compressor p, driving the projectile, and the associated projectile impact velocities are provided in SHPB_S355.xlsx. The DIC displacement measurements are provided in FurtherMeasurements/DIC with frame output times in the file labels, which are associated with an imaginary trigger at the left end of the shortened incident bar (length 300 mm), which is considered within the SHPB simulation setup, see [1]. Furthermore, the DIC reference coordinate systems are provided as COS.jpg files in the respective DIC folders. Starting from the strain signals at the bars, captured by strain gauges at the incident (file name BC_Inc) and transmission bar (BC_Trans), displacement boundary conditions (which are provided for the tests in FurtherMeasurements/BarDisplBCs) are calculated by eq. (12) in [1], incorporating the acoustic velocity equal to 4639 m/s at the bars and a correction factor. Fig. 1 shows the shear specimen geometry (lengths in mm) with the offset of the notches x. For the quasi-static tests force(displacements)-values are directly provided in FurtherMeasurements/Fu_curves, which are considered from the relative displacements of the specimens, evaluated by DIC. The Vickers microhardness (HV 0.01) distribution across the shear localization zone was assessed by QNESS 60A+ EVO (DIN EN ISO 6507-1) for quasi-statically and dynamically tested specimens, applying the small notch offset, such that the specimens did not fail in the localization region. Therefore, raw data is provided in FurtherMeasurements/Microhardness. For fitting the microhardness distribution perpendicularly to the shear bands (as i.e. provided for the SHPB specimen in [1]), representative microhardness profiles were considered. Similarly for specimens with the small notch offset, EBSD data on dynamic and quasi-static tests is provided in FurtherMeasurements/EBSD. The grain size distributions for positions at the notch and the undeformed region are included in the subdirectory ./GrainLists_Shortened and EBSD images in the PowerPoint Presentations. Further information as the sizes and misorientations of the single grains, is incorporated in the subfolders ./GrainLists_FurtherInf. KW - Adiabatic shear bands KW - Split Hopkinson pressure bar KW - Digital image correlation PY - 2025 DO - https://doi.org/10.5281/zenodo.17591439 PB - Zenodo CY - Geneva AN - OPUS4-64842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Al-Waqfi, R. A. A1 - Khan, C. J. A1 - Irving, O. J. A1 - Matthews, Lauren A1 - Albrecht, T. T1 - Crowding Effects during DNA Translocation in Nanopipettes N2 - Quartz nanopipettes are an important emerging class of electric single-molecule sensors for DNA, proteins, their complexes, as well as other biomolecular targets. However, in comparison to other resistive pulse sensors, nanopipettes constitute a highly asymmetric environment and the transport of ions and biopolymers can become strongly directiondependent. For double-stranded DNA, this can include the characteristic translocation time and tertiary structure, but as we show here, nanoconfinement can also unlock capabilities for biophysical and bioanalytical studies at the single-molecule level. To this end, we show how the accumulation of DNA inside the nanochannel leads to crowding effects, and in some cases reversible blocking of DNA entry, and provide a detailed analysis based on a range of different DNA samples and experimental conditions. Moreover, using biotin-functionalized DNA and streptavidinmodified gold nanoparticles as target, we demonstrate in a proof-of-concept study how the crowding effect, and the resulting increased residence time in nanochannel, can be exploited by first injecting the DNA into the nanochannel, followed by incubation with the nanoparticle target and analysis of the complex by reverse translocation. We thereby integrate elements of sample processing and detection into the nanopipette, as an important conceptual advance, and make a case for the wider applicability of this device concept. KW - DNA translocation KW - Transport KW - Resistive-pulse sensing KW - Nanopores KW - Nanopipettes KW - Crowding KW - Confinement PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630448 DO - https://doi.org/10.1021/acsnano.5c01529 SN - 1936-086X VL - 19 IS - 17 SP - 1 EP - 9 PB - ACS Publications AN - OPUS4-63044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Evans, Alexander A1 - Schröder, Jakob A1 - Pirling, T. A1 - Ulbricht, Alexander A1 - Suárez Ocaño, Patricia A1 - Bruno, Giovanni T1 - Resolving the Subsurface Residual Stress Maximum in Laser Powder Bed-Fused 316L Stainless Steel by Diffraction-Based Analysis N2 - Laser powder bed fusion (PBF-LB/M) is a metal additive manufacturing process. Due to the complex nature of the layer-wise, repeated heating and cooling cycles, it tends to generate high-magnitude residual stresses. If not correctly understood and mitigated through in- or post-process approaches, these residual stresses can be detrimental as they are often tensile at the surface. However, determining the magnitude and location of peak tensile residual stresses is not trivial as they are often located subsurface. This work focuses on determining the magnitude and location of these deleterious tensile residual stresses in a PBF-LB/316L specimen. Two diffraction-based Methods are used to reveal the relationship between the residual stresses and the underlying microstructure. On the one hand, high spatial resolution Neutron diffraction is used to determine triaxial stresses from the bulk to a depth of 0.15 mm. On the other hand, laboratory X-ray diffraction coupled with electrolytical layer removal allows the biaxial residual stress depth profile to be probed from the surface to a depth of about 0.6 mm. The results show a good agreement between the two methods. The peak residual stress is shown to be 500 MPa, which appears as a plateau between 0.08 and 0.35 mm in depth. KW - Residual stress KW - Diffraction KW - Laser Powder Bed Fusion KW - 316L KW - Additive manufacturing KW - Microstructure KW - AGIL PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652138 DO - https://doi.org/10.1007/s11837-025-07719-y SN - 1543-1851 VL - 77 IS - 12 SP - 9726 EP - 9737 PB - Springer Nature AN - OPUS4-65213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Belli, Renan A1 - Hartmann, Sabine A1 - Lubauer, Julia A1 - Pereira, Raíssa Monteiro A1 - Hurle, Katrin A1 - Yin, Ling A1 - Mieller, Björn A1 - Lohbauer, Ulrich T1 - Improving the chipping resistance of pre-sintered zirconia white-bodies N2 - Objectives: The high occurrence of fractures, cracking and chipping of zirconia pre-sintered blanks and blocks during machining decreases their yield and can transfer lifetime-limiting racks to the final sintered restoration. This study has the objective of characterizing the mechanical and fracture properties of two zirconia compositions while varying temperature and time of pre-sintering, in order to assess the space for possible improvement. Methods: We selected two typical granular powders with 3 mol% (3YSZ, Zpex®, Tosoh) or 5 mol% (5YSZ, Zpex Smile®, Tosoh) yttria-stabilized zirconia and two pre-sintered commercial analogs (IPS e.max® ZirCAD MO, Ivoclar and Katana™ STML, Kuraray). The debinding and pre-sintering stages of the experimental powders were characterized using thermal analyses (differential scanning calorimetry and thermogravimetry), and the crystal phase composition was quantified using X-ray diffraction (XRD). Physical and mechanical properties such as density, hardness, flexural modulus, biaxial flexural strength and fracture toughness were measured for two pre-sintering temperatures (1000 ◦C, 1100 ◦C) and increasing holding times at those temperatures (2 h, 4 h, 6 h). The chipping resistance for those conditions was quantified using the edge chipping test using a Vickers diamond indenter. Results: Thermal analyses revealed that both powders show comparable debinding behavior and contained approx. 3.8 mass % organic binder, which burns-out completely between 300 and 400 ◦C. The crystallographic phase changes occurring during the 2–6 h at 1000 ◦C and 1100 ◦C was not detectable in the DSC signal, but quantifiable by XRD. Namely, a major content of monoclinic phase in both powders transforms completely into the two tetragonal phases, starting below 1000 ◦C and concluding above 1100 ◦C. All physical and mechanical properties increased with holding time for both temperatures, though more steeply for pre-sintering at 1100◦C. Edge chipping resistance response was well aligned with other fracture properties, with a more marked improvement for 3YSZ pre-sintered at 1100 ◦C. For all properties, the 3YSZ zirconia showed statistically-higher values for the same temperature-time conditions, in agreement with the values obtained for the commercial materials as well. Significance: The results demonstrate the weakness of pre-sintered zirconia products concerning fracture properties, but also the potential for improvement as related to type of zirconia and pre-sintering conditions. This study outlines the use of a set of mechanical tests that can characterize chipping resistance and guide future research engaging in optimizing the machining resistance of pre-sintered zirconia products. KW - Zirconia KW - Fracture KW - White body KW - Dental materials KW - Pre-sintering PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653457 DO - https://doi.org/10.1016/j.dental.2025.12.012 SN - 0109-5641 SP - 1 EP - 12 PB - Elsevier Inc. AN - OPUS4-65345 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Skrotzki, Birgit T1 - Ermüdungsrisswachstum von warmfestem austenitischem Gusseisen unter isothermen und anisothermen Belastungen N2 - Das Ermüdungsrisswachstumsverhalten des warmfesten Gusseisens EN-GJSA-XNiSiCr35-5-2 (auch unter der Bezeichnung Ni-Resist D-5S bekannt) wurde bei Raum- und hoher Temperatur untersucht. Es wurden kraftgeregelte Versuche bei konstanten Temperaturen (20 °C, 500 °C, 700 °C) ohne und mit Haltezeit und unterschiedlichen Lastverhältnissen durchgeführt. Zusätzlich wurde das Risswachstumsverhalten auch unter TMF-Belastung (Tmin = 400 °C, Tmax = 700 °C) unter IP- und OP-Bedingungen charakterisiert. Die Überwachung des Rissfortschritts erfolgte durch die Kombination von drei verschiedenen Techniken: Potenzialabfall, Thermografie und Compliance-Methode. Die Auswirkungen der verschiedenen Belastungsbedingungen auf das Ermüdungsrisswachstum werden vorgestellt und diskutiert. T2 - Bauteilverhalten bei thermomechanischer Ermüdung CY - Berlin, Germany DA - 25.03.2025 KW - Gusseisen KW - Thermomechanische Ermüdung KW - Rissfortschritt KW - Risswachstum KW - Ermüdungsriss KW - Thermographie PY - 2025 AN - OPUS4-63185 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Singh, Shobhit Pratap A1 - Löwe, Peter A1 - Schriever, Sina A1 - Olbricht, Jürgen A1 - Rehmer, Birgit A1 - Nolze, Gert A1 - Skrotzki, Birgit T1 - High-throughput creep evaluation of IN738LC in bending using digital image correlation at 850 °C N2 - High-temperature alloys, when used in structural applications, undergo slow time-dependent deformation known as creep. Assessing creep behavior is critical for estimating the in-service life of these alloys. Conventionally, uniaxial creep tests are widely conducted at elevated temperatures to determine creep rates. In recent years, bending creep of cantilevers, when combined with digital image correlation (DIC), has emerged as a promising high-throughput technique for rapidly estimating creep life. However, the applicability of bending creep above 700 ◦C for high-temperature alloys using DIC has not been fully established. In this work, we compare uniaxial creep rates of the nickel-based superalloy IN738LC with bending creep rates measured at 850 ◦C using high-temperature DIC. The bending creep data show excellent agreement with uniaxial creep results in the stress range of 240–360 MPa. The measured creep xponent, a critical rate-determining parameter, is found to be ~8 for both uniaxial and bending creep, with the rate data scattered within a factor of two. An in-house experimental setup was developed to perform bending creep tests at high temperatures, with strain monitored through DIC. Our results demonstrate that bending creep, combined with DIC, provides a reliable and efficient method for creep testing of high-temperature alloys. Compared to conventional uniaxial creep experiments, this approach requires significantly less time and material, thereby reducing effort, energy, and cost. We anticipate that this technique will serve as a foundation for testing precious high-temperature materials. For instance, in ongoing rapid discoveries of advanced alloys, in-service creep life can be evaluated much faster with reduced material requirements. Moreover, this method holds strong potential for application to high-entropy alloys and additively manufactured alloys designed for demanding high-temperature environments. KW - Digital image correlation KW - Bending creep KW - Nickel-based superalloys KW - High throughput testing KW - High-temperature materials PY - 2025 UR - https://www.sciencedirect.com/science/article/pii/S0921509325017034?via%3Dihub DO - https://doi.org/10.1016/j.msea.2025.149479 VL - 950 SP - 1 EP - 12 PB - Elsevier B.V. AN - OPUS4-64814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Creep Behavior of Stainless Steel 316L Manufactured by Laser Powder Bed Fusion N2 - The broader industrial adoption of metal AM in safety-critical applications is limited, among others, by the still in-sufficient understanding of process–structure–property relationships and a lack of reliable mate-rial data. The content presented here approaches this limitation regarding the creep behavior of one of the most studied AM alloys: PBF-LB/M/316L stainless steel. A nearly as-built and a condition heat treated at 900 °C for 1 h, along with a conventionally manufactured variant are investigated. The creep behavior until reaching the minimum creep rate is mainly determined by the solidification cell structure. The damage is overall mainly intergranular, independent of the heat treated condition. The heat treatment at 900 °C for 1 h partially influenced the microstructure (mainly in terms of cell structure). The creep behavior until reaching the minimum creep rate remained nearly unchanged. The creep lifetime and ductility were enhanced. The crystallographic texture evolved after creep deformation. T2 - TMS 2025 Annual Meeting & Exhibition CY - Las Vegas, NV, USA DA - 23.03.2025 KW - AGIL KW - Creep KW - 316L KW - Microstructure PY - 2025 AN - OPUS4-63456 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beygi Nasrabadi, Hossein A1 - Klotz, Ulrich E. A1 - Tiberto, Dario A1 - Vafaeenezhad, Hossein A1 - Mishurova, Tatiana A1 - Skrotzki, Birgit T1 - Effect of keyhole and lack-of-fusion pores on the anisotropic microstructure and mechanical properties of PBF-LB/M-produced CuCrZr alloy N2 - Due to the high reflectance and heat conductivity of copper and its alloys, the processing window for laser-based powder bed fusion (PBF-LB/M) processing of high-density copper components fundamentally overlaps with conduction and keyhole melting zones, resulting in the emergence of certain pores in the structure of printed parts. The present research aims to study how the development of process-induced lack-of-fusion or keyhole porosities during the PBF-LB/M process can affect the anisotropic microstructure and mechanical properties of the produced copper alloys. For this purpose, several samples were produced utilizing a similar CuCrZr-feedstock composition but varied process parameters from different areas of the PBF-LB/M processing window, specifically at laser powers of 300 W and 380 W which define the boarders of the conduction and keyhole regimes. X-ray computed tomography (XCT) revealed that the 300-W and 380-W samples achieved relative densities of 98.88% and 99.99%, respectively, with elongated lack-of-fusion pores forming at 300 W and semi-spherical keyhole pores at 380 W. Microstructural analyses employing scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) demonstrated strong anisotropy in different build directions of the samples, owing to the growth of long columnar grains with intense < 101  orientation along the build directions. Here, the emergence of different types of pores can cause competition between the epitaxial growth of columnar grains and the heterogeneous nucleation of new grains on the layers’ interfaces, thereby significantly varying the grain size, preferred orientation, crystallographic texture, and microstructural anisotropy of the samples. Furthermore, compression tests and nanoindentation measurements of the printed alloys in the longitudinal and transverse directions revealed that the 300 W and 380 W samples exhibited compressive strength anisotropies of 0.061 and 0.072, and average nanoindentation hardness values of 1.3 GPa and 1.5 GPa, respectively. The orientation of elongated lack-of-fusion porosities perpendicular to the loading axis was identified as the most damaging factor, significantly reducing mechanical performance compared to the uniformly distributed keyhole pores. KW - Copper Alloy KW - Laser-based powder bed fusion KW - Microstructure KW - Mechanical properties KW - X-ray computed tomography (XCT) KW - Porosity KW - Anisotropy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625655 DO - https://doi.org/10.1007/s40964-025-00972-2 SN - 2363-9520 SP - 1 EP - 15 PB - Springer Science and Business Media LLC AN - OPUS4-62565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Jakob A1 - Fritsch, Tobias A1 - Ferrari, Bruno A1 - Altmann, Mika León A1 - Bruno, Giovanni A1 - Toenjes, Anastasiya T1 - Laser powder bed fusion: Defect type influences critical porosity re-growth during reheating after hot isostatic pressing N2 - Despite the remarkable product design flexibility offered by additive manufacturing (AM) techniques, such as laser powder bed fusion, AM processes are susceptible to the formation of defects. In this context, the control of process parameters and the application of post-processing treatments, such as hot isostatic pressing (HIP), are of paramount importance to achieve the desired mechanical properties. The present study investigates the effectiveness of HIP as a function of process parameters in laser powder bed fused Ti-6V-4Al (PBF-LB/Ti64) using X-ray computed tomography. The process parameters are modified to obtain reference samples with low porosity, lack of fusion defects, or keyhole porosity. In all instances, subsurface keyhole porosity was observed in the as-built parts. Moreover, it was found that the efficacy of pore closure is dependent on the specific defect type. In the case of low porosity and keyhole pores, HIP resulted in effective closure. Conversely, larger lack of fusion defects were not closed due to their interconnectivity and the entrapment of argon gas. Subsequent heat treatments above the β-transus temperature allowed the investigation of the impact of defect type on porosity re-growth. For the first time, we reveal that lack of fusion defects are affected by considerable pore re-growth during post-HIP heat treatments of PBF-LB/Ti64. Such phenomenon is driven by the increasing internal pore pressure and local creep deformation at high temperatures. In contrast, re-growth is limited in samples with low porosity or keyhole pores. KW - Additive Manufacturing KW - Hot Isostatic Pressing KW - Titanium KW - Laser Powder Bed Fusion KW - X-ray Computed Tomography KW - Heat Treatment KW - Porosity PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629289 DO - https://doi.org/10.1016/j.jmatprotec.2025.118839 VL - 340 SP - 1 EP - 9 PB - Elsevier B.V. AN - OPUS4-62928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Jakob A1 - Han, Ying A1 - Fritsch, Tobias A1 - Hejazi, Bardia A1 - Ulbricht, Alexander A1 - Skrotzki, Birgit A1 - Bruno, Giovanni T1 - X-ray computed tomography quantifies primary phases and reveals crack morphology in high-cycle fatigue of aluminum alloy EN AW-2618A N2 - Since the introduction of high-strength aluminum alloys understanding their fatigue behavior is of high interest for the structural integrity of engineering components, in this context, the alloy EN AW-2618A gains its high strength from both nanometer size precipitates and micrometer size primary phases. The latter phases are often identified as crack initiation sites. In this study, it uses a combination of synchrotron and laboratory-based X-ray computed tomography to image and quantify such primary phases and the fatigue cracks appearing in interrupted tests. Based on the gray-level differences in the synchrotron X-ray computed tomography scans, this study is able to distinguish low- and high-absorbing particles. The dominant (volume fraction >99%) high absorbing primary phase can be quantified in good agreement with results of Thermo-Calc calculations. To image the fatigue crack, laboratory X-ray computed tomography scans are performed at different tensile loads to open the crack. The results show that with an appropriate crack opening tensile load, the fatigue crack morphology can be reliably revealed. Based on these results, the influence of the primary phases on the fatigue crack initiation and propagation are discussed. KW - X-ray computed tomography KW - Fatigue KW - Aluminum KW - Primary phases PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632724 DO - https://doi.org/10.1002/adem.202500235 SN - 1527-2648 SP - 1 EP - 9 PB - Wiley-VCH CY - Weinheim AN - OPUS4-63272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beygi Narsabadi, Hossein A1 - Vafaeenezhad, H. A1 - Klotz, U.E. A1 - Tiberto, D. A1 - Hosseinabadi, F. A1 - Mishurova, Tatiana A1 - Bruno, Giovanni A1 - Skrotzki, Birgit T1 - XCT-assisted micromechanical modeling of the effect of pores on the plastic deformation and mechanical characteristics of PBF-LB/M-produced copper alloys N2 - Due to the low absorption of fiber laser by copper particles, the laser-based powder bed fusion (PBF-LB/M) processing of copper components is accompanied by the development of different types of porosities within the printed samples. This research aims to assess the consequences of various process-induced pores on the me chanical characteristics and deformation of PBF-LB/M-produced copper alloys. Several copper alloys were processed using metal-coated particles and varied laser intensities, yielding samples with different types and amounts of porosities. For instance, CuCrZr alloys processed at 325 J/mm³ and 257 J/mm³ had 0.009 % and 1.117 % porosities, dominated by keyhole and lack-of-fusion pores, respectively. Moreover, PBF-LB/M pro cessing of Cr- and Nb-coated CuNi3SiCr particles accompanied by the generation of 0.004 % and 1.861 % porosities within the samples, predominantly featuring metallurgical and oxidation pores, respectively. Compression and nanoindentation tests revealed that the CuNi3SiCr alloy exhibited superior mechanical properties compared to the CuCrZr sample (nanoindentation hardness values 2.2 GPa and 1.4 GPa, respectively), while the presence of lack-of-fusion pores notably diminished their mechanical performance. X-ray computed tomography (XCT) reconstruction slices and scanning electron microscopy (SEM) images were then used for developing the representative volume elements (RVEs) based micromechanical models. The micromechanical simulations established a structure-property correlation that can simulate the compressive deformation and mechanical characteristics of PBF-LB/M-produced copper alloys as a function of their incorporated pore characteristics. Due to the closure of the pores at the first stages of deformation, samples with minimal keyhole and metallurgical porosities exhibited homogeneous plastic deformation. On the other side, based on the JohnsonCook model, strain concentration and crack propagation around the lack-of-fusion pores lead to damage initi ation in the printed samples at a strain level of 5 % KW - X-ray Computed tomography KW - Defects KW - Copper alloys KW - PBF-LB/M KW - Micromechanics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624004 DO - https://doi.org/10.1016/j.msea.2025.147836 SN - 0921-5093 VL - 924 PB - Elsevier B.V. AN - OPUS4-62400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miliūtė, Aistė T1 - Structural evolution of ZrV2O7: supercell persistence revealing local and global structure duality N2 - In the AM2O7 family of negative thermal expansion materials (NTE), evidence of supercell at room temperature was reported following the Völlenke et al. discovery of missed superlattice due to the apparent linearity of the M-O-M bond in GeP2O7. Korthuis et al. and Khosrovani et al. demonstrated it to be true for cubic ZrV2O7 as well. It was concluded that at room temperature, the structure consists of 27 'subcells' with bent M2O7 groups that appear to form a linear configuration due to refinement of averaged position. However, around 100 °C, the transition to the “parent” cell was reported, where the cell volume increases, and the M-O-M angles are constrained by the Pa-3 space group symmetry to be 180°. We followed structural changes in the ZrV2O7 at high temperatures to demonstrate partial disorder within the crystal, local and global structural duality and supercell persistence at high temperatures. Total scattering measurements and Pair Distribution Function (PDF) analysis revealed that the experimental pattern cannot be fitted with the “parent structure” model, and only the 3×3×3 supercell model can correspond to local and global structures throughout the full 25-700 °C temperature range. We also show how short and long-range order within the crystal changes when approaching the phase transition, which might indicate the existence of coherent structural domains that evolve between order and disorder with increasing temperature. We further hypothesize how this can be related to the negative thermal expansion mechanism and the interpretation of structure solutions presenting data from high-temperature X-ray absorption fine structure (XAFS) and Transmission Electron Microscopy (TEM) measurements. T2 - 5th International Symposium on Negative Thermal Expansion and Related Materials (ISNTE-5) CY - Porto, Portugal DA - 29.07.2025 KW - NTE KW - Ab initio KW - PDF KW - CSM PY - 2025 AN - OPUS4-63874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miliūtė, Aistė T1 - Theoretical and experimental development of negative thermal expansion material ZrV2O7 N2 - Zirconium vanadate (ZrV2O7) is a well-known negative thermal expansion (NTE) material which stands out for its remarkable isotropic unit cell contraction over a broad temperature range (130°C < T < 800°C). This enables the fabrication of composites where the overall expansion coefficient can be tailored to a specific negative, positive, or neutral value. Consequently, such composite materials are attractive for many device applications because they can compensate for damage caused by thermal expansion. They are relevant to optical systems, electronic and biomedical applications. In this study, we implement ab-initio-based vibrational computations with partially treated anharmonicity (quasi-harmonic approximation (QHA), temperature-dependent effective harmonic potentials (TDEP)[5]) in combination with experimental methods to follow and rationalize the negative thermal expansion in this material, including the influence of the local structure disorder, microstructure, and defects. In analytical techniques that can provide structural information such as pair distribution function analysis (PDF), X-ray diffraction (XRD), and Extended X-ray Absorption Fine Structure (EXAFS), molecules and atoms are fit geometrically without consideration of atom interactions. Therefore, in combination with these methods, we also consider potential energy surfaces and conclude what structures are likely to form energetically in the full NTE temperature range, in addition to fitting experimental data geometrically. We also optimise experimentally fitted structures to their lowest energy configurations and re-generate comparative data to observe what differences would be visible experimentally. T2 - XLVIII International Congress of Theoretical Chemists of Latin Expression CY - Cartagena de Indias, Colombia DA - 13.07.2025 KW - NTE KW - Ab initio KW - QHA KW - TDEP KW - anharmonicity PY - 2025 AN - OPUS4-63873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miliūtė, Aistė T1 - How experimental and computational methods allow us to design negative thermal expansion materials N2 - Combined experimental and computational methods allow comprehensive understanding, design, and tailoring of material properties. We focus on a well-known negative thermal expansion (NTE) material, zirconium vanadate (ZrV2O7), and address synthesis, characterisation and validation of results with computational simulations. Experimental and computational X-ray diffraction and Raman spectroscopy data highlighted differences between phase-pure and multiphase ceramics. These techniques allowed us to distinguish subtle differences in the structure of the material. Based on ab initio simulated phonon data, unaffected by impurities or instrumental errors, we could interpret the Raman spectra and visualise Raman active atom vibrations. These computational models allowed better insight and further experimental improvement while high-quality experimental data granted the validation and improvement of computational simulation strategy. T2 - Application of Neutrons and Synchrotron Radiation in Engineering Materials Science CY - Hamburg, Germany DA - 23.03.2025 KW - NTE KW - Sol-gel KW - Ab initio KW - Raman KW - XRD PY - 2025 AN - OPUS4-62832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Suárez Ocaño, Patricia A1 - Ávila Calderón, Luis A1 - Agudo Jácome, Leonardo A1 - Rehmer, Birgit A1 - Mohr, Gunther A1 - Evans, Alexander A1 - Skrotzki, Birgit T1 - Effect of 700–900 °C heat treatments and room and high temperature tensile deformation on the microstructure of laser powder bed fused 316L stainless steel N2 - The effect of post-processing heat treatments on the hierarchical microstructure evolution and mechanical strength of the austenitic stainless steel 316L produced by laser powder bed fusion has been investigated. Heat treatments between 700 and 900 ◦C and 0.5 to 3 h, were applied to samples treated at 450 ◦C for 4 h. The results showed a stable microstructure at all studied temperatures and times in terms of grain size, morphology, aspect ratio, density of low-angle grain boundaries, and texture. However, temperature and time promoted the diffusion of segregated elements together with a reduction in dislocation density and disappearance of the cellular structure. This was associated with a reduction in hardness and tensile proof strength at both room and high temperature. In addition, microstructural characterization coupled with thermodynamic CALPHAD-based equilibrium calculations showed that the formation of carbides and intermetallic phases was already visible after annealing at 800 ◦C for 3 hours, although these intermetallics did not affect the tensile properties at this level. Analysis of the microstructure evolution after tensile deformation showed differences in the deformation mechanisms at room and high temperature, with twinning and martensitic transformation occurring at room temperature, the latter not widely reported for additively manufactured 316L. Finally, comparisons with similar materials produced under comparable conditions showed differences in the tensile properties, attributed to differences in chemical composition and the associated presence of stacking faults in the undeformed state. KW - Additive manufacturing KW - 316L stainless steel KW - Heat treatments KW - Tensile properties KW - Microstructure PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632471 DO - https://doi.org/10.1016/j.msea.2025.148469 SN - 0921-5093 VL - 939 SP - 1 EP - 24 PB - Elsevier CY - Amsterdam AN - OPUS4-63247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Han, Ying A1 - Schriever, Sina A1 - von Hartrott, Philipp A1 - Rockenhäuser, Christian A1 - Skrotzki, Birgit T1 - Creep dataset for aluminum alloy EN AW-2618A in the T61 and overaged condition 1000 h/190 °C N2 - The article presents creep data for the precipitation-hardened aluminum alloy EN AW-2618A, which was tested in its initial slightly underaged T61 condition and after being aged at 190 °C for 1000 h. The creep test temperatures ranged between 160 °C and 230 °C, and the applied initial stresses between 40 MPa and 290 MPa. The testing times reached up to 4700 h. 19 data sets are provided as creep strain vs. time series. A data schema originally developed to manage creep reference data of a single-crystalline nickel-based superalloy was adapted for the research data set of the polycrystalline aluminum alloy and used to enrich the test data with extensive metadata. The dataset can be used to calibrate and validate creep models. The creep data supplement the hardness and microstructure data that have been previously published. KW - Aluminum alloy EN AW-2618A KW - Aging KW - Overaging KW - High temperature KW - Creep PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641517 DO - https://doi.org/10.1016/j.dib.2025.112054 SN - 2352-3409 VL - 62 SP - 1 EP - 10 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-64151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Synthesis and testing of beta aluminate sodium electrolyte (BASE) for sodium ion battery development N2 - Sodium beta aluminate, or beta aluminate solid electrolyte (BASE), is an established material for tubular electrolytes in NaNiCl2 and NaS batteries, and a promising candidate for planar electrolytes in safe all solid-state batteries. The synthesis of BASE with high ionic conductivity is still challenging due to process dependent formation of different phases in the sintered material. However, to drive forward the development of active materials for all solid-state sodium ion batteries, the fabrication of solid electrolyte specimens with reproducible performance is required. With respect to the various testing scenarios in the field, for example cell assembly for cycling, electrolyte parts are needed in various shapes, sizes, and thicknesses in the lab. Different ceramic shaping technologies can be applied to produce such geometries, including pressing combined with green or hard machining, or tape casting combined with punching. Typically, different shaping technologies require adapted pre-treatment of the powder which might affect the resulting properties and thus need to be investigated. In this contribution, starting from the raw materials mixture, aspects of milling, drying, aqueous slurry preparation for tape casting, and firing are discussed with respect to particle size distribution, stability, energy consumption and resulting material properties. Finally, the fabrication and cyclic testing of Na/electrolyte/Na coin cells is presented. T2 - XIXth Conference of the European Ceramic Society / SBS6 International Sodium Battery Symposium CY - Dresden, Germany DA - 01.09.2025 KW - Ceramics KW - Beta aluminate solid electrolyte KW - Sodium ion battery PY - 2025 AN - OPUS4-64054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Han, Ying A1 - Schriever, Sina A1 - von Hartrott, Philipp A1 - Rockenhäuser, Christian A1 - Skrotzki, Birgit T1 - Dataset on the Creep Properties of EN AW-2618A Aluminum Alloy in the T61 and an overaged condition N2 - This publication contains comprehensive metadata and test results of constant force creep tests according to DIN EN ISO 204 on the aluminum alloy EN AW-2618A in the T61 condition (8 h/530 °C/quenching in boiling water followed by 28 h/195 °C/air cooling) and in an overaged condition (T61 + 1.000 h/190 °C). The test temperatures cover 160 °C, 180 °C, 190 °C, and 230 °C, and the initial stresses range between 40 MPa and 290 MPa. KW - Creep KW - Aging KW - Overaging KW - Aluminum alloy KW - EN AW-2618A KW - High temperature PY - 2025 DO - https://doi.org/10.5281/zenodo.15744297 PB - Zenodo CY - Geneva AN - OPUS4-63572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suarez Ocano, Patricia T1 - Exploring the impact of heat treatment on room and high temperature strength of 316L stainless steel fabricated by PBF-LB N2 - Laser Powder Bed Fusion (PBF-LB/M) enables the fabrication of 316L stainless steel components with superior strength and intricate geometries. The alloy PBF-LB/M/316L features a fully austenitic microstructure with hierarchical characteristics— such as fine dislocation structures, segregated elements, low-angle grain boundaries, and nano-dispersed silicates—that enhance strength and ductility. Additionally, it includes metallurgical defects and residual stresses. Apart from process control, heat treatments (HTs) are used to tailor the microstructure for specific loading conditions. This study investigate the effects of post-processing HTs on the hierarchical microstructure and tensile properties of PBF-LB/M/316L at room and high temperature. The heat treatments, ranging from 400 °C to 900 °C for 1 to 4 hours, focus on sub-recrystallization temperatures to preserve the microstructural hierarchy. The HTs applied had minimal impact on the grain shape, size, or texture of PBF-LB/M/316L. However, significant modifications occurred in the solidification cellular substructure after HTs at 800 °C and 900 °C, when compared to a heat-treated condition at 450 °C. HTs at 800 °C notably decreased dislocation density and enlarged cellular structures, though they remained partially intact. After 1 hour at 900 °C, the cellular substructure dissipated, correlating with a further reduction in dislocation density. These microstructural changes resulted in a decreased yield strength and increased work hardening capacity at both room and high temperature, highlighting the critical link between HT parameters, microstructural evolution, and mechanical performance. T2 - The 20th International Conference on Strength of Materials (ICSMA 20) CY - Kyoto, Japan DA - 02.06.2025 KW - Additive manufacturing KW - 316L stainless steel KW - Heat treatments KW - Tensile properties KW - Microstructure PY - 2025 AN - OPUS4-63914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Cyclic Deformation Behavior of Laser Powder Bed Fused Stainless Steel 316L Role of the Manufacturing Induced Cell Structure N2 - The cyclic deformation behavior of an austenitic 316L stainless steel produced by laser powder bed fusion in two heat treated conditions and featuring a low defect population is presented. Strain controlled push/pull tests were performed between room temperature and 600 °C. The PBF‑LB/M/316L exhibits an initial cyclic hardening, followed by a cyclic softening. The grade of softening decreases (i) with increasing test temperature and (ii) after a partial dissolution of its dislocation substructure through heat treatment. The deformation behavior and its dependency on test temperature and heat-treated/microstructural condition are attributed to the slip character and related changes. With either a partially dissolved dislocation substructure or increasing test temperature the material exhibits typical wavy slip characteristics. In the opposite case, the deformation mechanism seems to be rather planar dislocation slip as the formation of slip planes spanning through entire grains was observed, seemingly acting as pathways of easy dislocation movement. T2 - TMS 2025 CY - Las Vegas, Nevada, US DA - 23.03.2025 KW - AGIL KW - Additive Fertigung KW - Low-Cycle-Fatigue KW - Mikrostruktur KW - 316L PY - 2025 AN - OPUS4-64855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bhadeliya, Ashok A1 - Rehmer, Birgit A1 - Skrotzki, Birgit A1 - Jokisch, Torsten A1 - Olbricht, Jürgen A1 - Fedelich, Bernard T1 - Fatigue crack growth in nickel-based alloy 247DS with side-brazed pre-sintered preform N2 - Pre-sintered preform (PSP) brazing is employed in the repair of gas turbine components made of nickel-based alloys, including restoring the surface and dimensions of turbine blades and vanes. This study investigates the fatigue crack growth (FCG) behavior of Alloy 247DS specimens with side-brazed PSP material, mimicking a typical sandwich structure formed during such repairs. FCG tests were conducted at an elevated temperature of 950 °C and a stress ratio (R) of 0.1 on specimens with PSP layer thicknesses of 1.5 mm, 2 mm, 3 mm, and 4.5 mm to assess the influence of PSP thickness on fatigue crack growth behavior. Fractographic and metallographic analyses were performed to elucidate the underlying crack growth mechanisms and the microstructural characteristics of both materials. The results revealed that a crack consistently initiated in the PSP material, originating from the starter notch, particularly at the specimen corner during the pre-cracking phase. Additionally, crack propagation in the PSP material consistently advanced ahead of the crack in the Alloy 247DS. This crack growth behavior is attributed to the difference in elastic properties and microstructural differences between the PSP and base material. Metallographic analysis revealed the presence of porosity and brittle precipitates within the PSP material, which led to faster intergranular crack growth. Conversely, Alloy 247DS exhibited transgranular crack growth, contributing to the observed crack propagation behavior. This study demonstrates the applicability of standard FCG testing methods and an approach to characterize the FCG behavior in sandwich specimens, where crack growth occurs simultaneously in both materials, providing a preliminary understanding of crack growth behavior in Alloy 247DS with side-brazed PSP. KW - High-temperature fatigue crack growth (FCG) KW - Nickel-based alloys KW - Alloy 247DS KW - Pre-Sintered Preform (PSP) PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629783 DO - https://doi.org/10.1016/j.ijfatigue.2025.108961 VL - 197 SP - 1 EP - 13 PB - Elsevier BV AN - OPUS4-62978 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chahal, Shweta A1 - Xiao, Boyu A1 - Grant, Jessica A1 - Furniss, David A1 - Farries, Mark A1 - Phang, Sendy A1 - Neate, Nigel A1 - Robertson, Lorelei A1 - Roe, Martin A1 - Barney, Emma A1 - Seddon, Angela B. T1 - Ce3+-doped chalcogenide glass fibre for laser beyond 4 microns wavelength: Glass material-integrity N2 - The 4-μm wavelength barrier encountered for mid-infrared fibre lasing based on heavy metal fluoride glasses has been overcome. We reported, in 2021, the first continuous wave, mid-infrared fibre laser operating beyond 4 μm at room temperature in a fibre with a Ce3+-doped selenide-chalcogenide core. Defects, such as crystallites in the core glass, could cause unwanted light-scattering, diminishing fibre laser efficiency. It is important to identify such optical loss mechanisms and eradicate them. Here, we report on investigating the material nano-structure of a chalcogenide-glass lasing fibre which exhibits 7 mW laser power output; the fibre has a Ce3+-doped core (8.5 μm diameter), concentrically surrounded by an inner- and outer-cladding, where both cladding-glasses are nominally the same composition. High resolution transmission electron microscopy and electron diffraction show that the core, inner-cladding and outer-cladding of the lasing fibre are internally nano-crystallite-free and amorphous. However, the external outer surface of the last 10 m of fibre drawn, of the total 100 m, contains monoclinic GeSe2 crystallites adjacent to discrete, small (<0.5 mm) wrinkled defects. The final length of fibre is drawn from the final part of the glass fibreoptic preform. The glass preform has as its outermost component an extruded chalcogenide glass tube. It is the last part of the tube which spends the longest time at high temperature inside the extruder during tube manufacture, encouraging heterogeneous nucleation at the tube outer-surface in contact with the extruder. These heterogeneous nuclei subsequently nucleate crystal growth during fibre-drawing in the outermost fibre surface. KW - Optical glass KW - Photonics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653371 DO - https://doi.org/10.1016/j.optmat.2025.117219 SN - 0925-3467 VL - 166 SP - 1 EP - 14 PB - Elsevier CY - Amsterdam AN - OPUS4-65337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Towards Structured Data Spaces: Prototypical Application of Semantic Technologies as a Driver for Innovation in Materials Science N2 - In the pursuit of advancing development and digitalization within materials science, ensuring quality assurance, interoperability, and adherence to FAIR principles is significant. To address these aspects, semantic technologies are employed for storage, processing, and contextualization of data, offering machine-actionable and human-readable knowledge representations crucial for data management. This presentation showcases the prototypical application of generic approaches of knowledge representation in materials science. It includes the design and documentation of graph patterns that may be compiled into rule-based semantic shapes. The development and application of the PMD Core Ontology 3.0 (PMDco 3.0) tailored for materials science is highlighted. Its integration into daily lab life is demonstrated through its functional incorporation into electronic lab notebooks (ELN). Examples of material processing and standardized mechanical testing illustrate how knowledge graph operations enhance ELN capabilities, providing a generalizable unified approach for managing diverse experimental data from different sources with automation potentials. T2 - TMS Specialty Congress 2025 CY - Anaheim, CA, USA DA - 15.06.2025 KW - Semantic Data KW - Data Integration KW - Digitalization KW - Data Interoperability KW - Plattform MaterialDigital PY - 2025 AN - OPUS4-63401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ávila Calderón, Luis Alexander A1 - Matzak, Kathrin A1 - Olbricht, Jürgen A1 - Dolabella Portella, Pedro A1 - Skrotzki, Birgit T1 - BAM Reference Data: High Temperature Tensile Data of Single-Crystal Ni-Based Superalloy CMSX-6 N2 - This publication provides comprehensive metadata and test results of tensile tests at elevated temperature according to DIN EN ISO 6892-2:2018-09 on the single crystal Ni-based superalloy CMSX-6 at T = 980 °C. The tests were performed in an ISO 17025-accredited test laboratory. The calibrations of measuring equipment are documented, meet the requirements of the measurement standard, and are metrologically traceable. The provided data were audited and are BAM reference data. KW - Digitalisierung KW - Referenzdaten KW - CMSX-6 KW - Zugversuch KW - NFDI-MatWerk KW - Ni-Basis-Superlegierung PY - 2025 DO - https://doi.org/10.5281/zenodo.17846616 PB - Zenodo CY - Geneva AN - OPUS4-65338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eddah, Mustapha A1 - Markötter, Henning A1 - Mieller, Björn A1 - Widjaja, Martinus Putra A1 - Beckmann, Jörg A1 - Bruno, Giovanni T1 - Multi-energy high dynamic range synchrotron X-ray computed tomography N2 - Synchrotron X-ray computed tomography (SXCT) is regularly used in materials science to correlate structural properties with macroscopic properties and to optimize manufacturing processes. The X-ray beam energy must be adapted to the sample properties, such as size and density. If both strongly and weakly absorbing materials are present, the contrast to the weakly absorbing materials is lost, resulting in image artifacts and a poor signal-tonoise ratio (SNR). One particular example is a low-temperature co-fired ceramics (LTCC), in which metal connections are embedded in a ceramic matrix and form 3-dimensional conducting structures. This article describes a method of combining SXCT scans acquired at different beam energies, significantly reducing metal artifacts, and improving image quality. We show how to solve the difficult task of merging the scans at low and high beam energy. Our proposed merging approach achieves up to 35 % improvement in SNR within ceramic regions adjacent to metallic conductors. In this way, previously inaccessible regions within the ceramic structure close to the metallic conductors are made accessible. The paper further discusses methodological requirements, limitations, and potential extensions of the presented multi-energy SXCT merging technique. KW - Synchrotron computed tomography KW - Reconstruction algorithm KW - High dynamic range KW - Data merging KW - Low-temperature cofired ceramics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652339 DO - https://doi.org/10.1016/j.tmater.2025.100079 SN - 2949-673X VL - 9 SP - 1 EP - 10 PB - Elsevier CY - Amsterdam AN - OPUS4-65233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ginés-Palomares, Juan-Carlos A1 - Facchini, Leonardo A1 - Wilbig, Janka A1 - Zocca, Andrea A1 - Stoll, Enrico A1 - Günster, Jens T1 - Melt Pool Stability during Local Laser Melting of Lunar Regolith with Large Laser Spots and Varying Gravity N2 - In order to increase the sustainability of future lunar missions, techniques for in-situ resource utilization (ISRU) must be developed. In this context, the local melting of lunar dust (regolith) by laser radiation for the production of parts and larger structures was investigated in detail. With different experimental setups in normal and microgravity, laser spots with diameters from 5 mm to 100 mm were realized to melt the regolith simulant EAC-1A and an 80%/20% mixture of TUBS-T and TUBS-M, which are used as a substitute for the actual lunar soil. In the experiments performed, the critical parameters are the size of the laser spot, the velocity of the laser spot on the surface of the powder bed, the gravity and the wettability of the powder bed by the melt. The stability of the melt pool as a function of these parameters was investigated and it was found that the formation of a stable melt pool is determined by gravity for large melt pool sizes in the range of 50 mm and by surface tension for small melt pool sizes in the range of a few mm. KW - Additive Manufacturing KW - Regolith KW - Laser melting KW - ISRU PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639621 DO - https://doi.org/10.1016/j.amf.2025.200227 SN - 2950-4317 VL - 4 IS - 3 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-63962 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moschetti, Michael A1 - Lemiasheuski, Anton A1 - Bajer, Evgenia A1 - Porohovoj, Ilja A1 - Göbel, Artur A1 - Pfennig, Anja A1 - Bettge, Dirk A1 - Maaß, Robert T1 - Robot-Assisted Automated Serial-Sectioning and Imaging for 3D Microstructural Investigations N2 - Comprehensive materials characterization requires precise structural knowledge beyond traditional methods. The robot-assisted automated serial-sectioning and imaging (RASI) platform, developed at BAM, provides automated 3D metallographic reconstructions, enabling detailed microstructural analysis of technical materials. This article showcases RASI’s capabilities through several case studies, including characterization of lamellar graphite in gray cast iron, porosity in sintered steel, melt pool morphology in additively manufactured 316L stainless steel, defects in metal-ceramic packages, and oxidation behavior in an Fe-12Cr-2Co alloy. By automating sample handling, mechanical serial-sectioning, etching, and optical imaging, RASI captures complex 3D microstructures with high precision and at high speed. This approach reveals microstructural features missed by 2D analysis, even using stereological assumptions. Specifically, statistically rare and large microstructural features, such as secondary phases or interconnected pores, become apparent, which 2D methods cannot reveal. The generated volumetric data can furthermore serve as quantitative reference datasets (i.e., the ‘ground truth’) essential for validating other 3D characterization techniques and computational models, helping to bridge the gap between predictive simulations and real-world material behavior. RASI’s modular design makes it a flexible tool that provides realistic 3D insights into materials, which can be used for advanced materials research, process optimization, and quality control. KW - 3D metallography KW - Automated microstructure characterization KW - Image segmentation KW - Mechanical polishing based serial-sectioning KW - Process-microstructure-property relationships KW - Quantitative microstructure PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649614 DO - https://doi.org/10.1002/adem.202502202 SN - 1527-2648 VL - 28 IS - 2 SP - 1 EP - 14 PB - Wiley-VCH GmbH AN - OPUS4-64961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ikeda, Yuki A1 - Wallis, Theophilus A1 - Maaß, Robert A1 - Darvishi Kamachali, Reza T1 - Thermodynamics of grain boundary segregation transition and their relevance for liquid metal embrittlement in Fe-Zn system N2 - Grain boundaries (GBs) are common sites of failure in polycrystalline materials. Recently, a massive Zn segregation transition at Fe GBs was discovered and shown to act as a potent precursor of liquid metal embrittlement (LME) in the Fe-Zn system (Kamachali et al., Scripta Materialia 238 (2024) 115758). In this study, we elaborate on how temperature, GB type and the chemo-structurally coupled phase decomposition at the GB impact this segregation transition. CALPHAD and atomistic simulation data were utilized as inputs to conduct quantitative density-based thermodynamic modeling and phase-field simulations across various GBs, alloy compositions, and temperatures. We reveal that once the segregation transition becomes possible, the GB structural variation stabilizes spinodally formed Zn-rich phases within the GB region, with a higher tendency in disordered GBs. GB phase diagrams were constructed to identify and analyze the range of critical temperatures and alloy compositions associated with the segregation transition. The phase diagrams reveal that the miscibility gap for more disordered GB expands and, although the segregation transition is inevitable and occurs for all GBs, the barrier to triggering it is lower for more disordered GBs. Based on our thermodynamic analyses, potential processing modifications and GB engineering strategies for mitigating segregation-induced LME are thoroughly discussed. KW - Thermodynamics KW - Phase-Field Modelling KW - Steels PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634145 DO - https://doi.org/10.1016/j.actamat.2025.121134 SN - 1359-6454 VL - 296 SP - 1 EP - 11 PB - Elsevier BV AN - OPUS4-63414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chang, Yen-Ting A1 - Sharda, Abhi A1 - Rosalie, Julian M. A1 - Maaß, Robert A1 - Charpagne, Marie A. T1 - A bcc refractory high-entropy alloy: the ideal case of smooth plastic flow N2 - Single crystalline metals exhibit correlated dislocation dynamics, irrespective of lattice system. This collective evolution of dislocation structures is intermittent and scale-free, implying divergent length scales that play a critical role in failure initiation and therefore microstructural design. Here we report on a HfNbTaTiZr refractory high-entropy alloy, that lacks criticality in the collective dislocation response. This unusual behaviour manifests itself in almost quenched-out microplastic stress-strain fluctuations and sluggish dislocation avalanching, otherwise only seen in complex engineering alloys. These findings demonstrate how the high-entropy paradigm can serve as a role model to effectively suppress unwanted plastic fluctuations in metals deformation. KW - Plasticity KW - Dislocations KW - Avalanches KW - Refractory high-entropy alloys PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630241 DO - https://doi.org/10.1080/21663831.2025.2497860 SN - 2166-3831 SP - 1 EP - 8 PB - Taylor & Francis Group AN - OPUS4-63024 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dudziak, Mateusz A1 - Riechers, Birte A1 - Maaß, Robert A1 - Michalchuk, Adam A1 - Schönhals, Andreas A1 - Szymoniak, Paulina T1 - Beyond conventional calorimetry: Unlocking thermal characterization with fast scanning techniques N2 - Fast scanning calorimetry (FSC) has emerged as a transformative technique in thermal analysis, enabling the investigation of rapid and kinetically driven thermal transitions that are inaccessible to conventional differential scanning calorimetry. This review highlights the capabilities enabled by FSC for studying a wide range of materials under extreme thermal conditions, including polymers, pharmaceuticals, metallic glasses, nanocomposites, and hydrogels. By employing ultrafast heating and cooling rates, FSC allows for the suppression of crystallization, resolution of weak transitions, and analysis of thermally labile or size-limited samples. The technique is particularly valuable for probing glass transitions, relaxation phenomena, and phase behavior in systems with complex morphologies or confined geometries. Case studies demonstrate the use of FSC in characterizing vitrification, physical aging, and interfacial dynamics, as well as its application in emerging fields such as additive manufacturing, supramolecular systems, and neuromorphic materials. Together, these examples underscore the role that FSC plays in advancing the understanding of structure-property relationships across diverse material classes. KW - Flash DSC KW - Calorimetry KW - Glass transition PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647405 DO - https://doi.org/10.1016/j.tca.2025.180177 VL - 754 SP - 1 EP - 14 PB - Elsevier B.V. AN - OPUS4-64740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bekemeier, Simon A1 - Caldeira Rêgo, C. R. A1 - Mai, H. L. A1 - Sikia, Ujjal A1 - Waseda, O. A1 - Apel, M. A1 - Arendt, F. A1 - Aschemann, A. A1 - Bayerlein, Bernd A1 - Courant, R. A1 - Dziwis, G. A1 - Fuchs, F. A1 - Giese, U. A1 - Junghanns, K. A1 - Kamal, M. A1 - Koschmieder, L. A1 - Leineweber, S. A1 - Luger, M. A1 - Lukas, M. A1 - Maas, J. A1 - Mertens, J. A1 - Mieller, Björn A1 - Overmeyer, L. A1 - Pirch, N. A1 - Reimann, J. A1 - Schröck, S. A1 - Schulze, P. A1 - Schuster, J. A1 - Seidel, A. A1 - Shchyglo, O. A1 - Sierka, M. A1 - Silze, F. A1 - Stier, S. A1 - Tegeler, M. A1 - Unger, Jörg F. A1 - Weber, M. A1 - Hickel, Tilmann A1 - Schaarschmidt, J. T1 - Advancing Digital Transformation in Material Science: The Role of Workflows Within the MaterialDigital Initiative N2 - The MaterialDigital initiative represents a major driver toward the digitalization of material science. Next to providing a prototypical infrastructure required for building a shared data space and working on semantic interoperability of data, a core focus area of the Platform MaterialDigital (PMD) is the utilization of workflows to encapsulate data processing and simulation steps in accordance with findable, accessible, interoperable, and reusable principles. In collaboration with the funded projects of the initiative, the workflow working group strives to establish shared standards, enhancing the interoperability and reusability of scientific data processing steps. Central to this effort is the Workflow Store, a pivotal tool for disseminating workflows with the community, facilitating the exchange and replication of scientific methodologies. This article discusses the inherent challenges of adapting workflow concepts, providing the perspective on developing and using workflows in the respective domain of the various funded projects. Additionally, it introduces the Workflow Store’s role within the initiative and outlines a future roadmap for the PMD workflow group, aiming to further refine and expand the role of scientific workflows as a means to advance digital transformation and foster collaborative research within material science. KW - Digitalisation KW - FAIR principles KW - MaterialDigital KW - Scientific workflows KW - Semantic interoperability PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624088 DO - https://doi.org/10.1002/adem.202402149 SN - 1527-2648 IS - 2402149 SP - 1 EP - 25 PB - Wiley-VCH GmbH AN - OPUS4-62408 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chen, Yu A1 - Bo, Zhen-Xing A1 - Zhou, Hong Bo A1 - Sun, Bao-An A1 - Sun, Yong Hao A1 - Maaß, Robert A1 - Wang, Wei Hua T1 - Nanoindentation reveals universal scaling of pop-in plasticity in metallic glasses N2 - Plastic flow of metallic glasses proceeds intermittently in the inhomogeneous deformation regime. Mediated via shear bands, quasi-static straining gives rise to plastic instabilities that are measured as abrupt displacement bursts or pop-ins. The latter is a well-known feature in nanoindentation, where its first occurrence probes the critical and site-specific stress of nano-scale incipient shear deformation. Here we show that the statistical distribution of the stress and magnitude of the first shear instability, as well as its successive higher-order events, universally follow Weibull statistics across ten different metallic glasses. This indicates a fundamentally identical plastic process across glass-forming alloys and progressing deformation that is governed by a weakest-link phenomenon. This finding stands in strong contrast to crystalline alloys, where both defect nucleation and defect-structure evolution control shear instabilities and depend on the deformation history. KW - Metallic glasses KW - Nanoindentation KW - Intermittent flow KW - Pop-ins KW - Weibull distribution PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624772 DO - https://doi.org/10.1016/j.scriptamat.2025.116549 VL - 259 SP - 1 EP - 5 PB - Elsevier Inc. AN - OPUS4-62477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rashidi, Reza A1 - Riechers, Birte A1 - Rosalie, Julian A1 - Maaß, Robert T1 - Annealing-dependent elastic microstructure in a Zr-based metallic glass N2 - In this letter, we demonstrate the robust presence of an elastic microstructure in a Zr-based metallic glass (MG) with a characteristic length-scale of the order of 100 nm. This length scale increases systematically towards the MG surface in differently sized casts, whereas thermal relaxation homogenizes both the internal length-scale gradient and the magnitude of the elastic fluctuations. Strongest changes during relaxation arise in the stiffest parts of the elastic microstructure. These findings indicate that the elastic microstructure emerges due to cooling constraints and may therefore be a microstructural manifestation of the internal residual stresses that arise during MG-solidification. KW - Metallic glass KW - Heterogeneity KW - Elastic microstructure KW - Nanoindentation PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610962 DO - https://doi.org/10.1016/j.scriptamat.2024.116380 VL - 255 SP - 1 EP - 5 PB - Elsevier B.V. CY - Amsterdam, Niederlande AN - OPUS4-61096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, M. A1 - Schubert, Nils A1 - Günster, Jens A1 - Stawarczyk, B. A1 - Zocca, Andrea T1 - Additive manufacturing of glass-ceramic dental restorations by layerwise slurry deposition (LSD-print) N2 - This study is dedicated to the additive manufacturing of a feldspar glass-ceramic for dental applications by LSD-print (layerwise slurry deposition) technology, a variation of binder jetting using water-based ceramic slurries as feedstock. This technology was investigated for the manufacturing of single tooth restoration demonstrators with good aesthetic properties, and to compare the additively manufactured material with a commercial reference. Model restorations with > 99 % relative density were processed with a debinding and firing cycle of 45 min, however the whole process chain accounts for up to 30 hours. Significant differences between LSD-printed and reference materials were found for fracture strength, fracture toughness and Martens parameters. Printing orientation affected shrinkage and fracture strength, but not fracture toughness and Martens parameters. Nevertheless, the results suggest that the LSD-print technology processing the developed slurry is a promising option for manufacturing dental restorations meeting class 1a requirements according to DIN EN ISO 6871:2019–01. KW - Additive Manufacturing KW - 3D-printing KW - LSD-print KW - Dental ceramics KW - Glass-ceramic KW - Debinding KW - Firing KW - Sinter-crystallization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624768 DO - https://doi.org/10.1016/j.jeurceramsoc.2025.117235 VL - 45 IS - 7 SP - 1 EP - 13 PB - Elsevier Ltd. AN - OPUS4-62476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens T1 - Continuous layer deposition for the Additive Manufacturing of ceramics by Layerwise Slurry Deposition N2 - Powder bed technologies are among the most successful additive manufacturing (AM) techniques. The application of these techniques to most ceramics has been difficult due to the challenges associated with the deposition of homogeneous powder layers when using fine powders. In this context, layerwise slurry deposition (LSD) has been developed as a deposition method that enables the use of powder bed AM technologies for advanced ceramic materials. In layerwise slurry deposition, a ceramic slurry is deposited in layers using a doctor blade and dried to produce a highly compacted powder. Not only can very fine submicron powders with low organic content be processed, but the dense powder bed also provides excellent support for the manufactured parts. The latest development of this technology shows that it is possible to print ceramic parts in a continuous process by depositing a layer on a rotating platform on which a powder bed grows in a spiral motion. The unique mechanical stability of the layers in LSD printing makes it possible to build up a powder bed several centimeters thick without lateral support. Continuous layer deposition achieves more than 10 times the productivity of linear deposition, approaching a build volume of 1 liter per hour. T2 - International Conference on Additive Manufacturing Technology Frontiers CY - Xi’an, China DA - 11.04.2025 KW - Ceramic KW - advanced ceramics PY - 2025 AN - OPUS4-63963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - A unique authenticator for additively manufactured parts derived from their microstructure N2 - In the field of additive manufacturing, the ability to uniquely identify and authenticate parts is crucial for certification, logistics, and anti-counterfeiting efforts. This study introduces a novel methodology that leverages the intrinsic microstructural features of additively manufactured components for their identification, authentication, and traceability. Unlike traditional tagging methods, such as embedding QR codes on the surface [1] or within the volume of parts, this approach requires no alteration to the printing process, as it utilizes naturally occurring microstructural characteristics. The proposed workflow [2] involves the analysis of 3D micro-computed tomography data to identify specific voids that meet predefined identification criteria. This method is demonstrated on a batch of 20 parts manufactured with identical process parameters, proving capable of achieving unambiguous identification and authentication. By establishing a tamper-proof link between the physical part and its digital counterpart, this methodology effectively bridges the physical and digital realms. This not only enhances the traceability of additively manufactured parts but also provides a robust tool for integrating digital materials, parts databases, and product passports with their physical counterparts. T2 - Artificial Intelligence in MSE CY - Bochum, Germany DA - 18.11.2025 KW - Authentication KW - Additive Manufacturing KW - Non-destructive testing PY - 2025 AN - OPUS4-65204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller-Elmau, Johanna T1 - 2PP of ceramic – What’s next? N2 - Photon-based additive manufacturing technologies such as SLA, DLP, LCM, moreover volumetric two-photon-polymerization (2PP), Xolography and holographic technologies promise the highest accuracy and dimensional freedom. To transfer the light through the feedstock it needs sufficient transparency. Ceramic particles used for powder processing routes act as scattering sites and therefore hinder the light transmission, unless… The particle size and particle size distribution are chosen small and narrow enough. Particles smaller than roughly 1/10th of the light wavelength, mostly nanoparticles around 5nm size, decrease scattering vastly. This turns resins even with homogeneously distributed ceramic weight fraction of up to 80% transparent again. Feedstocks were prepared for the highly accurate two-photon-polymerization gaining the smallest yttria stabilized zirconia structures with a resolution of 500nm and unique mechanical properties. The same feedstock was applied to DLP and LCM as layer-by-layer AM-technologies for bigger parts. Hybridizing both technologies enables ceramic parts with microscopic accuracy at macroscopic dimensions. The feedstock was even applied to the volumetric Xolography with the highest transparency requirement so far and to versatile and flexible holographic AM. What are the next steps? Can those proof-of -concept studies be transferred to industrial applications and what are the hurdles on the way? How to make the stretch between fundamental research and application-oriented development? T2 - ECERS CY - Dresden, Germany DA - 31.08.2025 KW - Tranparent KW - Ceramic KW - Two-photon-polymerization PY - 2025 AN - OPUS4-64939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ginés-Palomares, Juan-Carlos A1 - Baasch, Julian A1 - Stapperfend, Simon A1 - Facchini, Leonardo A1 - Linke, Stefan A1 - Stoll, Enrico A1 - Günster, Jens T1 - Laser Melting vs. Laser Sintering: Large Area Heat Processing of Lunar South Pole Simulant N2 - A key component of future lunar missions is the concept of In-Situ Resource Utilization (ISRU), which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies. This paper investigates the thermal processing capability of lunar regolith without the addition of binders, with a focus on large-scale applications for the construction of lunar habitats and infrastructure. The study used a simulant of lunar regolith found on the Schrödinger Basin in the South Pole region. This regolith simulant consists of 20 wt% basalt and 80 wt% anorthosite. Experiments were conducted using a high power CO2 laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing. Results indicated that sintering begins at approximately 1,180 °C and reaches full melt at temperatures above 1,360 °C. Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick, while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick. The energy efficiency of the sintering and melting processes was compared. The melting process was about 10 times more energy efficient than sintering in terms of material consolidation, demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements. KW - Additive Manufacturing KW - Laser melting KW - ISRU KW - Moon KW - Regolith PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639614 DO - https://doi.org/10.1016/j.amf.2025.200226 SN - 2950-4317 VL - 4 IS - 3 SP - 1 EP - 13 PB - Elsevier Ltd. AN - OPUS4-63961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Abel, Andreas T1 - Microstructural and mechanical characterisation of cast Fe-Al-Mo-Ti-B alloys N2 - With the advent of variable renewable energies, long-term energy storage capacities and flexible power generation technologies will be required for reliable grid stability. Hence, power plant technologies and turbomachinery components will continue to be developed and employed for efficient re-conversion of stored energy. With the introduction of new working fluids for higher thermal efficiencies, the working conditions of exposed components and materials will require higher corrosion resistance, but with the same mechanical performance, manufacturability and cost. Intermetallic iron aluminide alloys with their outstanding oxidation and corrosion resistance and good high-temperature properties depict a possible candidate for use in high-temperature structural applications. A quinary Fe-26Al-4Mo-0.5Ti-1B solid-solution alloy with eutectic particle hardening particularly demonstrated competitive mechanical properties compared to high-alloy P92 steels in previous studies. To derive standard material specifications with industrially relevant casting strategies, centrifugal investment-cast Fe-25Al-3.7Mo-0.4Ti-1B was characterised with respect to microstructure, thermophysical properties and mechanical properties under quasi-static tensile and creep loading up to 700 °C. Compared to P92 steel, the alloy demonstrated superior tensile strength above 550 °C and lower creep rates at 650 °C if stresses increase above 170 MPa. At lower temperatures though, the mechanical properties were inferior to P92 steel and related Fe-Al-Mo-Ti-B alloys, which was correlated to large grain sizes, a high tendency to surface and bulk cracking and a pronounced effect of tension-compression asymmetry. In further studies on alloy composition with varying Al, Mo and B concentration, a non-linear relationship of solid-solution hardening with solute Mo concentration was found. In this regard, halving Mo was the most effective measure for reducing brittleness without decreasing strength at room and elevated temperatures. Higher solidification rates and grain refinement down to 30 µm by die casting had a positive effect on ambient tensile strength, but were not achievable by investment casting. Dilatometry and hardness measurements indicated a low thermal vacancy hardening effect which was less sensitive to low-temperature annealing than in B2 FeAl alloys. Although mechanical properties up to 550 °C could be considerably improved by alloy development and processing, ductility at room temperature generally remained below 1%, necessitating substantial design margins for components from Fe-Al-Mo-Ti-B alloys. Despite the inherent limitations of alloy and casting process, the gained insights will help to prioritise future areas of research to mature cost-effective higher-order Fe Al alloys for high-temperature structural applications. KW - Hardness KW - Iron aluminide alloy KW - Micro structure KW - Tensile strength KW - Creep strength PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632810 DO - https://doi.org/10.5445/IR/1000181739 SP - 1 EP - 179 PB - Karlsruher Institut für Technologie (KIT) CY - Karlsruhe AN - OPUS4-63281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -