TY - CONF A1 - Reinsch, Stefan T1 - Oriented Surface Crystallization in Glasses N2 - Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied at the Institute of Physics of Rennes in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation. T2 - ACerS GOMD 2024- Glass & Optical Materials Division Meeting CY - Las Vegas, NV, USA DA - 19.05.2024 KW - Surface nucleation KW - Oriented surface crystallization KW - Surface energy PY - 2024 AN - OPUS4-60238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, P. T1 - The contribution of the Platform MaterialDigital (PMD) in building up a Materials Data Space - Application to glass design and manufacturing N2 - Suitable material solutions are of key importance in designing and producing components for engineering systems – either for functional or structural applications. Materials data are generated, transferred, and introduced at each step along the complete life cycle of a component. A reliable materials data space is therefore crucial in the digital transformation of an industrial branch. A great challenge in establishing a materials data space lies in the complexity and diversity of materials science and engineering. It must be able to handle data from different knowledge areas over several magnitudes of length scale. The Platform MaterialDigital (PMD) is expected to network a large number of repositories of materials data, allowing the direct contact of different stakeholders as materials producers, testing labs, designers and end users. Following the FAIR principles, it will promote the semantic interoperability across the frontiers of materials classes. In the frame of a large joint initiative, PMD works intensively together with currently near 20 research consortia in promoting this exchange (www.material-digital.de). In this presentation we will describe the status of our Platform MaterialDigital. We will also present in more detail the activities of GlasDigital, one of the joint projects mentioned above dealing with the digitalization of glass design and manufacturing. (https://www.bam.de/Content/EN/Projects/GlasDigital/glasdigital.html) T2 - OntoCommons Workshop CY - Berlin, Germany DA - 04.04.2023 KW - Ontology KW - Materials Data Space KW - PMD KW - Glass PY - 2023 AN - OPUS4-60371 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan T1 - A new robot-assisted compositional screening method N2 - The system Na2O.B2O3-SiO2 (NBS) is the basis of many industrial glass applications and therefore one of the most studied systems at all. Glass formation is possible over a wide compositional range, but the system also contains ranges of pronounced phase separation and crystallization tendency. Despite its importance, experimental data are limited to few compositional areas. The general understanding and modelling of glass formation, phase separation, and crystallization in this system would therefore be easier if small step melt series could be studied. The efficient melting of such glass series is now possible with the new robotic glass melting system at the Federal Institute for Materials Research and Testing (BAM, Division Glasses). Using three exemplary joins within this NBS system, the small step changes of glass transition temperature (Tg), crystallization behavior as well as glass density (Roh) was studied. Additionally, experimental Tg and Roh data were compared with their modeled counterparts using SciGlass and a newly developed DFT model, respectively. T2 - Annual meeting of the French Union for Science and Glass Technology (USTV) and the 96th Annual Meeting of the German Society of Glass Technology - USTV-DGG joint meeting. CY - Orléans, France DA - 22.05.2023 KW - Robot-assisted galss melting KW - Sodiumborosilicate glasses KW - Density KW - Glass transformation temperature KW - Property simulation PY - 2023 AN - OPUS4-58724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arendt, F. A1 - de Camargo, Andrea Simone Stucchi A1 - Chen, Y.-F. A1 - Gogula, S. A1 - Kilo, M. A1 - Waurischk, Tina T1 - GlasDigital N2 - Der aktuelle Stand des MateriaDigital Projektes GlasDigital wird vorgestellt. Hierbei wird allgemein die Problem- und Zielstellung präsentiert, als auch auf 2 separaten Postern die Ergebnisse. Diese beinhalten zum Einen die smarte Gestaltung der robotergestützten Glasschmelzanlage der BAM inkl. Analytik und zum Anderen die Digitalisierungsbestrebungen im Bereich Glas, d.h. ML-gestützte C-S-P-Simulation, Ontologie für den Werkstoff Glas, Digitaler Zwilling des Gießprozesses. T2 - PMD Vollversammlung 2023 CY - Karlsruhe, Germany DA - 21.09.2023 KW - GlasDigital KW - Ontologie KW - Bildanalyse KW - Simulation KW - Roboter KW - Digitalisierung PY - 2023 AN - OPUS4-58734 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kilo, M. T1 - New Approaches for the Preparation and Characterisation of New Glasses N2 - The new robot-assisted glass melting device at BAM is presented by the manufacturing team within the joint project GlasDigital together with an automatic thermo-optical measurement technique. T2 - UST-DGG joint meeting CY - Orléans, France DA - 23.05.2023 KW - Glass melting KW - Thermo-optical measurement PY - 2023 AN - OPUS4-58733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan T1 - Oriented Surface Crystallization in Glasses N2 - Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied at the Institute of Physics of Rennes in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation. T2 - 13th International Symposium on Crystallization in Glasses and Liquids CY - Orléans, France DA - 24.09.2024 KW - Surface crystallization KW - Surface energy KW - Crystal orientation KW - Silicate glass PY - 2024 AN - OPUS4-62219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf T1 - GlassDigital: Digital Infrastructure for Data-Driven High-Throughput Glass Development N2 - Gläser zeichnen sich durch eine breite und kontinuierlich abstimmbare chemische Zusammensetzung sowie einzigartige Formgebungstechniken aus, was sie oft zur Schlüsselkomponente moderner Hochtechnologien macht. Die Glasentwicklung ist jedoch oft noch zu kosten-, zeit- und energieintensiv. Der Einsatz von robotergestützten Schmelzsystemen, eingebettet in eine Ontologie-basierte digitale Umgebung, soll diese Probleme in Zukunft überwinden. Im Rahmen der BMBF Forschungsinitiative MaterialDigital unternimmt das Verbundprojekt GlasDigital „Datengetriebener Workflow für die beschleunigte Entwicklung von Glas“ erste Schritte in diese Richtung. Das Projektkonsortium, an dem das Fraunhofer ISC in Würzburg, die Friedrich-Schiller-Universität Jena (OSIM), die Technische Universität Clausthal (INW) und die Bundesanstalt für Materialforschung und -prüfung (BAM, Fachgruppe Glas) beteiligt sind, will alle wesentlichen Basiskomponenten für eine beschleunigte datengetriebene Glasentwicklung zusammenführen. Zu diesem Zweck wird ein robotergestütztes Hochdurchsatz-Glasschmelzsystem mit neuartigen Inline-Sensoren zur Prozessüberwachung, auf maschinellem Lernen (ML) basierenden adaptiven Algorithmen zur Prozessüberwachung und -optimierung, neuartigen Werkzeugen für die Hochdurchsatz-Glasanalyse sowie ML-basierten Algorithmen zum Glasdesign, Data Mining sowie Eigenschafts- und Prozessmodellierung ausgestattet. Der Vortrag gibt einen Überblick darüber, wie all diese Komponenten miteinander verzahnt sind, und veranschaulicht ihre Nutzbarkeit anhand einiger Beispiele. T2 - HVG-Fortbildungskurs CY - Offenbach, Germany DA - 27.11.2023 KW - Glas KW - Ontology KW - Workflow KW - Simulation KW - Robotic melting PY - 2023 AN - OPUS4-60386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - GlasDigital - Datengetriebener Workflow für die beschleunigte Glasentwicklung N2 - Im Projekt GlasDigital sollen digitale Werkzeuge für die Hochdurchsatzentwicklung neuartiger Glaswerkstoffe erarbeitet werden. Dies soll durch die Kombination robotischer Syntheseverfahren mit selbstlernenden Maschinen und ihre Einbindung in eine Ontologie-basierte digitale Infrastruktur realisiert werden. T2 - 4. Fachsymposium der Fachgruppe Glasapparatebauer CY - Mitterteich, Germany DA - 13.06.2024 KW - Glas KW - Ontology KW - Data Space KW - Simulation KW - Workflow KW - Robotische Schmelzanlage PY - 2024 AN - OPUS4-60388 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - Digital infrastructure for accelerated glass development N2 - Glasses stand out by their wide and continuously tunable chemical composition and large variety of unique shaping techniques making them a key component of modern high technologies. Glass development, however, is still often too cost-, time- and energy-intensive. The use of robotic melting systems embedded in an ontology-based digital environment is intended to overcome these problems in future. For this purpose, a robotic high throughput glass melting system is equipped with novel inline sensors for process monitoring, machine learning (ML)-based, adaptive algorithms for process monitoring and optimization, novel tools for high throughput glass analysis and ML-based algorithms for glass design. This includes software tools for data mining as well as property and process modelling. The presentation provides an overview of how all these tools merge into a digital infrastructure and illustrates their usability using examples. All infrastructural parts were developed by a consortium consisting of the Fraunhofer ISC in Würzburg, the Friedrich-Schiller-University Jena (OSIM), the Clausthal University of Technology (INW) and the Federal Institute for Materials Research and Testing (BAM, Division Glasses) as part of a joint project of the German research initiative MaterialDigital. T2 - 97. Glass-Technology Conference CY - Aachen, Germany DA - 27.05.2024 KW - Glass KW - Robotic melting KW - Ontologie KW - Simulation KW - Workflow KW - Data Space KW - Digital Twin PY - 2024 AN - OPUS4-60387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf T1 - GlasDigital: Data-driven workflow for accelerated glass development N2 - Glasses stand out by their wide and continuously tunable chemical composition and large variety of unique shaping techniques making them a key component of modern high technologies. Glass development, however, is still often too cost-, time- and energy-intensive. The use of robotic melting systems embedded in an ontology-based digital environment is intended to overcome these problems in future. As part of the German research initiative MaterialDigital, the joint project GlasDigital takes first steps in this direction. The project consortium involves the Fraunhofer ISC in Würzburg, the Friedrich Schiller University Jena (OSIM), the Clausthal University of Technology (INW), and the Federal Institute for Materials Research and Testing (BAM, Division Glasses) and aims to combine all main basic components required for accelerated data driven glass development. For this purpose, a robotic high throughput glass melting system is equipped with novel inline sensors for process monitoring, machine learning (ML)-based, adaptive algorithms for process monitoring and optimization, novel tools for high throughput glass analysis and ML-based algorithms for glass design, including software tools for data mining as well as property and process modelling. The talk gives an overview how all these tools are interconnected and illustrates their usability with some examples. T2 - USTV-DGG joint meeting CY - Orleans, France DA - 22.05.2023 KW - Glass KW - Ontology KW - Data Space KW - Workflow KW - Robotic melting PY - 2023 AN - OPUS4-60372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blaeß, Carsten T1 - Undesired Foaming of Silicate Glass Powders N2 - The manufacture of sintered glasses and glass-ceramics, glass matrix composites, and glass-bounded ceramics or pastes is often affected by un-expected gas bubble formation also named foaming. Against this background, in this presentation the main aspects and possible reasons of foaming are shown for completely different glass powders: a barium silicate glass powders used as SOFC sealants, and bioactive glass powders using different powder milling procedures. Sintering and foaming were measured by means of heating microscopy backed up by XRD, differential thermal analysis (DTA), vacuum hot extraction (VHE), optical and electron microscopy, and infrared spectroscopy, and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Different densification was reached followed by significant foaming starting partly immediately, partly at higher temperature. Foaming increased significantly as milling progressed. For moderately milled glass powders, subsequent storage in air could also promote foaming. Although the milling atmosphere significantly affects the foaming of uniaxially pressed powder compacts sintered in air. VHE studies show that foaming is driven by carbon gases and carbonates were detected by Infrared spectroscopy to provide the major foaming source. Carbonates could be detected even after heating to 750 °C, which hints on a thermally very stable species or mechanical trapping or encapsulating of CO2. Otherwise, dark gray compact colors for milling in isopropanol indicate the presence of residual carbon as well. Its significant contribution to foaming, however, could not be proved and might be limited by the diffusivity of oxygen needed for carbon oxidation to carbon gas. T2 - Seminário de Laboratório de Materiais Vítreos (LaMaV) de Departamento de Engenharia de Materiais (DEMa), Universidade Federal São Carlos UFSCar) CY - Saint Charles, Brazil DA - 06.06.2024 KW - Bioactive KW - Foaming KW - Glass KW - Crystallization KW - Viscose sintering PY - 2024 AN - OPUS4-60245 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Diegeler, A. T1 - Digital material data based glass screening for the systematic development of new glasses N2 - Current German developments for accelerated glass development is presented to an international audience at GOMD 2023. The focus is on a screening device which is embedded in a digital infrastructure. T2 - GOMD CY - New Orleans, LA, USA DA - 04.06.2023 KW - Glass KW - Robotic melting PY - 2023 AN - OPUS4-60376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kilo, M. T1 - New Approaches for the Preparation and Characterisation of New Glasses N2 - The new robot-assisted glass melting device at BAM is presented by the manufacturing team within the joint project GlasDigital together with an automatic thermo-optical measurement technique. T2 - USTV-DGG joint meeting CY - Orleans, France DA - 22.05.2023 KW - Glass KW - Robotic melting PY - 2023 AN - OPUS4-60374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stargardt, Patrick T1 - H2 permeability of soda-lime, borosilicate and vitreous silica glasses for potential high pressure H2 storage applications N2 - Modern high-pressure H2 tanks consist of fiber-reinforced composite materials and a plastic lining on the inside. The use of glass would drastically increase the H2 barrier effect. This could be achieved with glass liners or fiber-reinforced polymer-bonded glass capillary storage tanks and would enable lower wall thicknesses, higher gravimetric storage densities and variable designs and thus a much more effective use of space. However, the decisive material parameters for the development of these technologies, such as the hydrogen permeation, are unknown. This study focuses on H2 diffusion in glasses of different chemical compositions. H2 permeation is measured by mass spectrometry. For this purpose, the mass spectrometer (MS), which is located in a high vacuum, is separated from the pressure side by the test specimen. Pure H2 gas is present on the pressure side, so that the mass flow is recorded qualitatively and quantitatively in the MS. The permeation coefficients are calculated from the sample geometry and the mass flow rates. The very low H2 permeation of glass is measured on bundles of thin-walled commercially available glass capillaries and compared with the hydrogen permeation data of the glass powder method. T2 - Jahrestagung der Deutschen Glastechnischen Gesellschaft 2024 CY - Aachen, Germany DA - 27.05.2024 KW - Gas permeation KW - Hydrogen gas KW - High pressure gas storage PY - 2024 AN - OPUS4-60420 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - GlasDigital N2 - Der aktuelle Stand (Sep 2023) des Projekts GlasDigital wird präsentiert. Der Fokus liegt hierbei auf einer knappen Übersicht, aus der die nachhaltigen Beiträge für die Innovationsplattform MaterialDigital hervorgehen. T2 - PMD Vollversammlung CY - Karlsruhe, Germany DA - 21.09.2023 KW - Glas KW - Robotische Schmelzanlage KW - Ontologie KW - Simulation PY - 2023 AN - OPUS4-60377 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh T1 - Damage Mechanisms of Scarf Joint Repairs for Wind Turbine Rotor Blade Shell Applications N2 - Wind turbine rotor blades, made of fiber reinforced polymers (FRP), often fail before their projected 20-year lifespan, largely due to defects that originate during manufacturing and are propagated by operational fatigue and environmental conditions. The cost-intensive replacement outcomes lead to a high loss of earnings, and are one of the inhibitors of wind turbine production [1]. A potential repair alternative is to locally patch these areas of the blades with adhesively bonded structural repairs. However, the effects of such repair methods of the outer shell region on the structural integrity of the rotor blades are still largely unknown, and are thus investigated in this project. The shell components of rotor blades are made of FRP composite material sandwiching a lightweight core, often a rigid foam or Balsa wood. The repair methods involve replacing the lost load path with a new material that is joined to the parent structure [2]. Repairs in this project focus on the scarf method, which allow for a smoother load distribution across the joint, aiming to study the damage mechanism of glass FRP scarf repairs for wind turbine blade shell applications. Namely, the source and path of the damage initiation and propagation, role of the interface between parent and patch material, and the role of the fiber orientation mismatch at this interface are examined. Biaxial ±45° and 0/90° FRP specimens are produced with the vacuum-assisted resin infusion (VARI) process using E-glass non-crimp fabric. The patch layers are then joined using VARI with a scarf ratio of 1:50, using glass FRP fabric with half the areal weight of the parent side to allow for better drapability. The methods and practices in specimen production are based on common industry practice in rotor blade shell manufacturing and repairs. The specimens are tested under uniaxial tensile load, during which they are periodically monitored for damage onset. A comparison of the ±45° and 0/90° specimens allows for an understanding of the role of a highly mismatching fiber orientation in the transition zone between parent and patch material on the failure mechanism of the scarf joint. Although failure in both orientations begins as delamination at the joint edge, the difference in the mechanisms at play in the two different specimen types leads ultimately to different fracture paths. Namely, in the inter fiber failure mechanism of the ±45° specimens, the higher interlaminar strength compared to the intralaminar strength of the laminate leads to intralaminar failure of the ±45° scarf joint specimens. Alternatively, the competition in the 0/90° specimens lies between the interlaminar strength and fiber failure strength, and here we experience failure primarily across the scarf joint length. The scarf joint in the 0/90° specimens disrupts the continuity of the load-carrying 0° layers, directing the failure path to remain primarily along the scarf joint. Experimental results are compared to finite element analyses of scarf patch repairs on glass FRP sandwich specimens with the same respective layup orientations, where the damage initiation regions are identified and correlated to fiber orientation, serving as a bridge to future work which will experimentally examine the scarf repair patches on sandwich shell specimens. T2 - Joint Event: ICCS23 - 23rd International Conference on Composite Structures & MECHCOMP6 - 6th International Conference on Mechanics of Composites CY - Online meeting DA - 01.09.2020 KW - Wind turbine blade shells KW - Glass fiber reinforced polymers KW - Scarf repairs PY - 2020 AN - OPUS4-51175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Popiela, Bartosz T1 - FEM-Analyse der Reparaturstellen an FKV-Sandwichplatten N2 - Untersuchung des Einflusses des Reparaturpatches auf das Verhalten der reparierten GFK-Sandwichproben unter Zug-, Druck- und Schubbeanspruchung. T2 - 25. Nationales SAMPE-Symposium CY - Kassel, Germany DA - 18.02.2020 KW - Rotorblätter KW - Glasfaserverstärkter Kunststoff KW - Sandwichstruktur PY - 2020 AN - OPUS4-50544 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella T1 - The contribution of the Platform MaterialDigital (PMD) in building up a Materials Data Space - Application to glass design and manufacturing N2 - Suitable material solutions are of key importance in designing and producing components for engineering systems – either for functional or structural applications. Materials data are generated, transferred, and introduced at each step along the complete life cycle of a component. A reliable materials data space is therefore crucial in the digital transformation of an industrial branch. A great challenge in establishing a materials data space lies in the complexity and diversity of materials science and engineering. It must be able to handle data from different knowledge areas over several magnitudes of length scale. The Platform MaterialDigital (PMD) is expected to network a large number of repositories of materials data, allowing the direct contact of different stakeholders as materials producers, testing labs, designers and end users. Following the FAIR principles, it will promote the semantic interoperability across the frontiers of materials classes. In the frame of a large joint initiative, PMD works intensively together with currently near 20 research consortia in promoting this exchange (www.material-digital.de). In this presentation we will describe the status of our Platform MaterialDigital. We will also present in more detail the activities of GlasDigital, one of the joint projects mentioned above dealing with the digitalization of glass design and manufacturing. (https://www.bam.de/Content/EN/Projects/GlasDigital/glasdigital.html) T2 - Onto Commons Workshop CY - Berlin, Germany DA - 04.04.2023 KW - Ontology KW - Data space PY - 2023 AN - OPUS4-58732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf T1 - GlasDigital: Data-driven workflow for accelerated glass development N2 - Glasses stand out by their wide and continuously tunable chemical composition and large variety of unique shaping techniques making them a key component of modern high technologies. Glass development, however, is still often too cost-, time- and energy-intensive. The use of robotic melting systems embedded in an ontology-based digital infrastructure might overcome these problems. As part of the German research initiative MaterialDigital [1], the joint project GlasDigital took first steps in this direction combining all main components required for accelerated data driven glass development. For this purpose, a robotic high throughput glass melting system was equipped with inline sensors for process monitoring, machine learning (ML)-based adaptive algorithms for process monitoring and optimization, novel tools for high throughput glass analysis and ML-based algorithms for glass design, including data mining as well as property and process modelling. The talk gives an overview how these tools are interconnected and illustrates their usability. T2 - 27th International Congress on Glass 2025 CY - Kolkata, India DA - 20.01.2025 KW - Materials digitalisation PY - 2025 AN - OPUS4-63820 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - Internal friction and energy dissipation during crack propagation in silicate glasses N2 - To obtain a deeper insight into the nature of energy dissipation during crack propagation, the internal friction of 13 borosilicate, aluminosilicate, soda-lime, and lead-containing glasses, for which inert crack growth data are available in the literature, was measured using dynamic mechanical thermal analysis. For asymmetrically bent glass beams, the loss tangent tanδ 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 tanδ vs. T/Tg curve correlates with the crack growth exponent, n, in the empirical v ~ KIn relation between crack growth velocity, v, and stress intensity, KI. This correlation was most distinct for T/Tg < 0.3, still clear for T/Tg < 0.5, but not found for T/Tg > 0.8. The observed results indicate that n correlates with the degree of energy dissipation of relaxation phenomena below Tg. T2 - 27th International Congress on Glass 2025 CY - Kolkata, India DA - 20.01.2025 KW - Internal friction KW - Energy dissipation KW - Crack propagation KW - Silicate glasses PY - 2025 AN - OPUS4-63819 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Busch, Richard T1 - Surface Initiated Structure Formation in Glass Ceramics N2 - A summery of previous research regarding surface crystallization is given as well as results regarding thecurrent DFG project are presented. T2 - XRM Workshop CY - Halle, Germany DA - 03.03.2020 KW - Glass KW - Surface KW - XRM PY - 2020 AN - OPUS4-51337 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan T1 - Orientierte Oberflächenkristallisation in Gläsern N2 - Bislang wird das Phänomen der orientierten Oberflächenkristallisation kontrovers diskutiert und entsprechende Studien beschränken sich auf nur wenige Gläser. Für Silikatgläser haben wir eine gute Korrelation zwischen der berechneten Oberflächenenergie von Kristallflächen und der orientierten Oberflächenkeimbildung gefunden. Die Oberflächenenergien wurden unter der Annahme abgeschätzt, dass die Kristalloberflächen bei der Keimbildung den Kristallebenen mit minimaler Energie entsprechen, denen ein Riss beim Bruch folgt. Dieses Konzept wurde am Institut für Physik in Rennes erfolgreich bei der Berechnung der Bruchflächenenergien von Gläsern angewandt. Mehrere orientierte Keimbildungsphänomene lassen sich dadurch erklären, dass man annimmt, dass Kristalloberflächen mit hoher Energie dazu neigen, von der Schmelze benetzt zu werden. Dies minimiert die gesamte Grenzflächenenergie des Keims. Darüber hinaus werden wir die Entwicklung der Mikrostruktur beim weiteren Kristallwachstum und ihre Auswirkungen auf die bevorzugte Kristallorientierung diskutieren. T2 - 21. Treffen des DGG-DKG Arbeitskreises „Glasig-kristalline Multifunktionswerkstoffe“ CY - Mainz, Germany DA - 22.02.2024 KW - Oberflächenkeimbildung KW - Kristallorientierung KW - Grenzflächenenergie PY - 2024 AN - OPUS4-60237 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Thuy, Maximilian A1 - Brauch, N. A1 - Niebergall, Ute A1 - Alig, I. A1 - Oehler, H. A1 - Böhning, Martin T1 - Environmental Stress Cracking of PE-HD Induced by Liquid Test Media Representing Crop Protection Formulations N2 - Packaging containers for dangerous goods that include aggressive liquids require that any packaging material that is based on high-density polyethylene has a high degree of stability and durability. This work is focused on testing the environmental stress cracking of the high-density polyethylenes used for such containers in contact with crop protection formulations, in particular, two model liquids established in Germany as standardized test media representatives for crop protection formulations containing the various admixtures typical for such products. One of the liquids is water-based and contains mostly surface-active ingredients, while the other is solvent-based and includes some emulsifiers. Originally established for pin impression tests, these model liquids and their individual components were here used for the first time as environmental media in the Full Notch Creep Test, which addresses the resistance against environmental stress cracking. The Full Notch Creep Test was carried out on five high-density polyethylene types with both model liquids, and also on one selected material with its components. The evaluation was focused on the fracture surface structures, which were visualized by a scanning electron microscope and by optical in situ imaging of the notch opening. While the water-based model liquid and its surface-active individual components induced environmental stress cracking with the characteristic pattern for a craze-crack mechanism and so-called brittle fracture on the surface, the solvent-based model liquid and its soluble ingredients exhibited rather ductile failure behavior, caused by the plasticizing effect on the polymer that reduced the yield stress of the high-density polyethylene. For both cases, fracture surface analysis, together with side views of the crack opening, showed a clear relation between surface pattern, notch deformation (e.g., by blunting), or crack opening due to crack growth with time to failure and the solubility of the liquids in high-density polyethylene. KW - Environmental stress cracking KW - Fracture surface KW - Full Notch Creep Test KW - Crop protection formulations KW - High-density polyethylene PY - 2023 DO - https://doi.org/10.1520/STP164320210095 SP - 317 EP - 341 PB - ASTM International CY - West Conshohocken, PA (USA) AN - OPUS4-57459 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thuy, Maximilian T1 - Umgebungsbedingter Spannungsriss: Gefahr für Kunststoffbauteile unter Medieneinfluss N2 - Polyethylen hoher Dichte (PE-HD) ist ein weit verbreitetes Material für Transportbehälter, die oft für eine längere Nutzungsdauer vorgesehen sind. Insbesondere in diesem Fall können mikroskopische Schäden im Material auch weit unterhalb der Streckgrenze auftreten, die durch eine Spannungskonzentration verursacht werden, deren Ursprung in intrinsischen Materialfehlern oder äußeren Kratzern liegt. Mit fortschreitender Schädigung bilden sich Rissstrukturen, die von verstreckten Fibrillen aufgespannt werden, bis es zum Versagen dieser Fibrillen kommt und sich der Riss ausbreitet. Dieser Schadensmechanismus des langsamen Risswachstums kann durch eine Vielzahl von Umgebungsmedien beschleunigt werden und wird dann als "environmental stress cracking" (ESC) bezeichnet. Eine international normierte Methode zur Validierung der Spannungsrissbeständigkeit von PE-HD Materialien ist der „Full Notch Creep Test“ (FNCT). Anhand von Bruchflächenauswertungen mittels Rasterelektronenmikroskopie und Laser-Scanning-Mikroskopie, werden die typischen Schädigungsstrukturen des ESC sichtbar. Die fibrillierten Strukturen des ESC auf der Bruchfläche von PE-HD ergeben sich besonders bei oberflächenaktiven wässrigen Umgebungsmedien. In Lösungsmittel-Umgebungsmedien, im Zusammenspiel mit PE-HD, kommt es aufgrund der plastifizierenden Wirkung zur Herabsetzung der Streckspannung und Bruchflächen aus dem FNCT veranschaulichen keine signifikanten Anzeichen des Schädigungsmechanismus ESC. T2 - 47. VDI-Jahrestagung Schadensanalyse 2021- Mediale und klimatische Beanspruchung von polymeren Produkten CY - Würzburg, Germany DA - 06.10.2021 KW - Umgebungsbedingter Spannungsriss KW - Polyethylen hoher Dichte KW - Full Notch Creep Test KW - Lösungsmittel KW - Oberflächenaktive wässrige Medien KW - Bruchflächenauswertung PY - 2021 AN - OPUS4-53665 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Alig, I. T1 - Charakterisierung von Behälterwerkstoffen aus Polyethylen N2 - Das langsame Risswachstum (slow crack growth, SCG) sowie der umgebungsbedingte Spannungsriss (environmental stress cracking, ESC) sind relevante Schädigungsmechanismen für teilkristalline Werkstoffe auf Basis von Polyethylen hoher Dichte (PE-HD). Der Vortrag gibt einerseits einen Überblick über die grundlegenden Struktur-Eigenschafts-Beziehungen in diesem Kontext, andererseits werden auch verschiedene praxisorientierte Prüfverfahren vorgestellt. Letztere wurden in gemeinsamen Forschungsprojekten von BAM und LBF mit dem Schwerpunkt Gefahrgutbehälter bzw. Pflanzenschutzmittel vergleichend untersucht und durch weitergehende Analytik ergänzt. T2 - 16. Tagung des Arbeitskreises Polymeranalytik Webkonferenz, Fraunhofer LBF und FGK CY - Online meeting DA - 22.03.2022 KW - Polyethylen KW - Full Notch Creep Test KW - Environmental Stress Cracking KW - Spannungsriss PY - 2022 AN - OPUS4-54547 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thuy, Maximilian T1 - Damage progression of environmental stress cracking affected by manufacturing process-induced microstructural orientation N2 - Currently, the Full Notch Creep Test (FNCT) [1] method is used by material suppliers and end users in industry for the approval of container and pipe materials based on high-density polyethylene (PE-HD). The resistance to environmental stress cracking (ESC) of the material is evaluated using the time to failure of the specimen in an aqueous solution of a detergent [2, 3]. Usually specimens made of sheets with isotropic material properties, manufactured by hot pressing, are employed in order to obtain intrinsic properties of the material in terms of ESC failure. In contrast, the processes used in manufacturing to form containers and pipes, such as extrusion blow molding or extrusion, impose anisotropic properties to the material. These are mostly due to a microstructural orientation (polymer chains or crystallites) [4]. Furthermore, the different cooling conditions significantly affect the size distribution of crystallites as well as the overall morphology. It is therefore essential to understand the influence of process-induced material characteristics on failure due to ESC. A large number of studies on material properties as a function of microstructural preferential orientation have already been conducted [5-7]. However, effects on ESC as the major failure mechanism of containers and pipes are still rather unexplored [8, 9]. The most important factor is whether primarily intramolecular high-strength covalent bonds or the substantially weaker intermolecular van der Waals forces are predominantly loaded. In addition to the widely established classification by time to failure, the strain or crack opening displacement (COD) provides valuable information about the evolution and progression of damage as a function of time [10, 11]. Optical strain measurement using digital image correlation allows the differences in COD for isotropic and different angles of orientation of anisotropic specimens to be discussed. Also, a post-fracture surface analysis provides clarification on the craze-crack mechanism of the ESC. These different ESC-related properties of extruded and hot-pressed specimens have been investigated at different environmental medium temperatures and different initial stresses to provide a broad characterization of the fracture behavior of PE-HD. T2 - 36th International Conference of the Polymer Processing Society CY - Montreal, Canada DA - 26.09.2021 KW - Environmental stress cracking KW - High-density polyethylene KW - Fracture behavior KW - Microstructural orientation PY - 2021 AN - OPUS4-53400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Semantic Technologies for Digital Transformation in Materials Science: From PMDco to Prototypical Applications N2 - The digital transformation of Materials Science and Engineering (MSE) is accelerating the adoption of structured, interoperable, and FAIR data practices, in particular with respect to an advanced research data management. Semantic technologies play a pivotal role in this transformation, as the enable the integration, contextualization, and automation of diverse data sources across experimental, computational, and simulation domains. Central to these efforts is the Platform MaterialDigital Core Ontology (PMDco), now in version 3.0, which provides a robust mid-level semantic framework tailored for MSE. PMDco bridges abstract high-level ontologies, such as the Basic Formal Ontology (BFO) standardized in ISO/IEC 21838-2, with domain-specific terminologies to ensure consistency and interoperability across applications. This presentation explores the application of PMDco and its integration into workflows within the Platform MaterialDigital (PMD) initiative. Through its deployment in electronic laboratory notebooks (ELNs), PMDco enables semantic representation of experimental data, such as tensile test results compliant with ISO 6892-1:2019-11, transforming them into machine-actionable knowledge graphs. Prototypical implementations demonstrate how semantic technologies enhance laboratory processes, improve data reuse, and streamline documentation which offers opportunities for automation and education. Further extending its versatility, PMDco serves as a linking point for semantically representing simulation data, enabling comprehensive integration of experimental and computational datasets. This creates structured data spaces that support advanced digital workflows. Beyond PMDco, the presentation highlights the design of graph patterns and semantic shapes, showcasing generalizable methods for managing diverse data in MSE being based on data structuring and formatting. By presenting best practices in ontology development, data acquisition, and knowledge graph generation, this talk underscores the transformative potential of semantic technologies in MSE. It offers a forward-looking perspective on the role of structured data spaces as a driver for innovation, ensuring that materials science continues to advance through rigorous, interoperable, and automated digital methodologies. T2 - FEMS Euromat 2025 CY - Granada, Spanien DA - 14.09.2025 KW - Semantic Data KW - Data Integration KW - Digitalization KW - Data Interoperability KW - PMD Core Ontology KW - Graph Patterns PY - 2025 AN - OPUS4-64165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan T1 - Robot-assisted compositional screening in the System Na2O-Al2O3-B2O3-SiO2 N2 - The system Na2OB2O3SiO2 (NBS) is the basis of many industrial glass applications and therefore one of the most studied systems at all. Glass formation is possible over a wide compositional range, but the system also contains ranges of pronounced phase separation and crystallization tendency. Even small addition of Al2O3can change this behavior essentially. As the Na2OAl2O3B2O3SiO2 (NABS) system is also known as the basis for glasses in strength-relevant applications, the behavior during the transition from the NBS system to the NABS system is of interest. Therefore, some small step melt series in these systems were studied using the robotic glass melting system at the Federal Institute for Materials Research and Testing (BAM, Division Glasses). For these series the small step changes of glass transition temperature, crystallization behavior as well as glass density were studied. Additionally, experimental data were compared with their modeled counterparts. T2 - 98. Glastechnische Tagung CY - Goslar, Germany DA - 26.05.2025 KW - Sodium alumino boro silicate glasses KW - Glass transition temperature KW - Density KW - Robotic melting PY - 2025 AN - OPUS4-64076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Linden, Anna T1 - AMVAD - Additive manufacturing for ventricular assist devices N2 - Some children are born with a univentricular heart, meaning their heart has only one pumping chamber instead of two. To improve circulation, patients often undergo the Fontan procedure, which reroutes blood flow — but this can put stress on other organs. In some cases, ventricular assist devices, or VADs, are used to support the heart’s pumping function. This involves an artificial pump connected directly to the patient's heart via silicone-based cannulas. Unique anatomical conditions introduce special challenges for cannula geometry. Additive manufacturing offers innovative solutions by enabling the production of personalized medical devices. The aim of the project is to develop the manufacturing workflow for the individualized cannula from digital imaging of the patient and customized design to additive manufacturing. Besides technical feasibility, validating the entire process is crucial for regulatory approval. The selection and testing of suitable additive manufacturing processes and biocompatible materials for individualized silicone cannulas, ensuring compliance with quality standards for high-risk medical products, will be presented. T2 - AMBER Spotlight On: 3D Printing meets Health & Biotech CY - Berlin, Germany DA - 16.09.2025 KW - Additive manufacturing KW - Medical device KW - Liquid silicone rubber PY - 2025 AN - OPUS4-64101 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Panzier, Nicole A1 - Zocca, Andrea T1 - Silikatkeramik und Hochleistungskeramik aus dem 3-D-Druck N2 - In diesem Artikel werden die verschiedenen additiven Fertigungsverfahren und ihre Anwendungsmöglichkeiten vorgestellt. Der Fokus liegt hierbei auf Silikatkeramik. Für jedes 3D Druckverfahren werden die Möglichkeiten mit Silikatkeramik, Hochleistungskeramik und Dentalkeramik aufgezeigt. Auf den Nutzen der verschiedenen 3D Druckverfahren für industrielle Anwendungen, den privaten Bereich, sowie die Verwendung für Kunst und Design wird eingegangen. Das Potenzial der Additiven Fertigung wird auch für den Bereich der Keramik in der dentalen Anwendung bewertet. KW - Additive Fertigung KW - 3D Druck KW - Silikatkeramik KW - Hochleistungskeramik PY - 2022 UR - https://www.quintessence-publishing.com/deu/de/article/3634513/quintessenz-zahntechnik/2022/12/silikatkeramik-und-hochleistungskeramik-aus-dem-3-d-druck SN - 0340-4641 VL - 48 IS - 12 SP - 1260 EP - 1268 PB - Quintessence Publ. CY - Berlin AN - OPUS4-56792 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Transforming Materials Science with Concepts for a Semantically Accessible Data Space N2 - The digital transformation in materials science enables more efficient and sustainable processes. Through technological adaptations and a commitment to the FAIR principles, materials and processes are holistically addressed across entire value chains. The Platform MaterialDigital (PMD) and related initiatives are developing innovative solutions to the challenges of digitalization. The focus is on the interoperable integration of heterogeneous materials and processes data in semantically accessible data spaces. An ontological framework, based on the PMD Core Ontology and application-specific ontologies, promotes semantic interoperability of cross-domain and multi-scale (meta)data. This framework can be extended through natural language processing in a script-supported manner, as demonstrated with the Microscopy Ontology. The presentation further highlights how freely available mechanical and microstructural datasets of various aging stages of an aluminum alloy can be semantically integrated and flexibly searched. Graph-based operations enable links between processing and microstructural properties to be established, facilitating enhanced correlation analysis and pattern recognition. T2 - TMS Specialty Congress 2025 CY - Anaheim, CA, USA DA - 15.06.2025 KW - FAIR Data KW - Semanitc Interoperability KW - Community KW - Reproducibility PY - 2025 AN - OPUS4-63474 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Data-Driven Materials Science Supported by Community, Reproducibility, and Standardization N2 - Reproducible research in materials science demands a strong community and shared semantic standards. The interdisciplinary nature of the field has led to fragmented data practices, hampering collaboration and integration. Digitalisation initatives such as the German MaterialDigital Initiative addresses this by fostering a community-driven approach to FAIR data management, using ontologies to build consensus and semantic interoperability. Through interactive events like the Ontology Playground, a unified data culture that accelerates innovation and ensures reproducibility across materials research is supported. T2 - Seminar of the Person Group CY - Berkeley, CA, USA DA - 23.06.2025 KW - FAIR Data KW - Semantic Interoperability KW - Community KW - Reproducibility PY - 2025 AN - OPUS4-63475 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Franchin, G. A1 - Zocca, Andrea A1 - Karl, D. A1 - Yun, H. A1 - Tian, X. T1 - Editorial: Advances in additive manufacturing of ceramics N2 - Recently, additive manufacturing of ceramics has achieved the maturity to be transferred from scientific laboratories to industrial applications. At the same time, research is progressing to expand the boundaries of this field into the territory of novel materials and applications. This feature issue addresses current progress in all aspects of additive manufacturing of ceramics, from parts design to feedstock selection, from technological development to characterization of printed components. KW - Additive manufacturing KW - Ceramic PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549361 DO - https://doi.org/10.1016/j.oceram.2022.100277 SN - 2666-5395 VL - 10 SP - 1 EP - 2 PB - Elsevier CY - Amsterdam AN - OPUS4-54936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina T1 - Sintering of silver‑alkali zinc borate glass‑composites N2 - Since decades electric contacts based on silver metallization pastes are key components of photovoltaics and advanced microelectronics. For the metallization of commercial Si solar cells, high conductive silver glass pastes are cost effectively applicated by screen printing. Nevertheless, silver pastes are still one of the most crucial and expensive none Si materials in solar cells. Ever shorter time to market as well as increasing demands on reduced Ag consumption and line width require the targeted development of silver-glass-pastes with increased sinter ability and electrical conductivity. As a main difficulty, however, the liquid phase sintering of silver glass pastes is poorly understood so far. In the present study, the influence of different network modifier in alkali-zinc-borate paste glasses on liquid phase sintering of silver-glass-pastes was investigated. Low melting X2O-ZnO-B2O3 glasses with X = Na, Li and Rb (abbr. LZB, NZB, and RZB) were utilized to prepare silver-glass-composites containing 30 %Vol glass. Shrinkage behavior of the silver-glass-composites compared with that of pure silver and pure glass powder compacts was studied with heating microscopy. The powder compacts were uniaxially pressed and heated at 5 K/min to the glass softening temperature. Glass transformation temperature and viscosity of the glasses were respectively measured with dilatometry and rotational viscometry. The thermal behavior of the pure glasses was analyzed with thermal analysis. Additionally, the contact angle of glass on pure silver foil was determined by means of heating microscopy between room temperature and 830 °C. Thermal analysis of the alkali-zinc-borate-glasses under study has shown transformation temperatures between 450 °C (RZB), 460 °C (LZB) and 465 °C (NZB). For all glasses crystallization was found to start approximately at about 550 °C. However, different peak areas hint on a different degree of crystallization. Conformingly, the sintering behavior, measured in terms of area shrinkage, significantly differed for the silver-pastes under study. For silver-pastes with NZB or LZB-glass, sintering starts at 464 °C for NZB Ag pastes and at 451 °C for LZB Ag pastes and ends at 597 °C for NZB Ag paste and at 594 °C for LZB Ag paste. The sintering of the RZB Ag paste proceeds between 426 °C and 703 °C. The final densification was retarded possibly due to crystallization or swelling. The low sinter onset at 426 °C seems to correlate with the good wetting behavior of the RZB glass. Thus, the lowest apparent contact angle between the just densified powder compact sintered at a silver substrate was found for this glass. Moreover, microstructure analyses of the various composites indicate differences in silver dissolution and reprecipitation. T2 - Technology Crossover Extravaganza, HiTEC/CICMT/APEPS CY - Online meeting DA - 26.04.2021 KW - Silver-glass-metallization-paste KW - Sintering KW - Crystallization KW - Alkali ions KW - Sintering atmosphere PY - 2021 AN - OPUS4-52872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf T1 - Sintering and Foaming of Silicate Glass Powders N2 - The lecture focuses on the mechanisms of non-desired gas bubble formation and foaming during the sintering of glass powder compacts. It is shown that foaming is driven by carbon gases and that carbonates, encapsulated in micropores or mechaniacally dissolved beneath the glass surface, provide the major foaming source. T2 - Sandanski Workshop Sinter crystallization 27th-29th September 2021 PROJECT “THEORY AND APPLICATIONS OF SINTER-CYSTALLIZATION” DN 19/7 CY - Online meeting DA - 27.10. 2021 KW - Sintering KW - Non-desired foaming PY - 2021 AN - OPUS4-53772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blaeß, Carsten T1 - 3D printing of crystallizing bioactive glasses N2 - Artificial bone replacement by individual customized three-dimensional resorbable bioactive glass has not yet been widely established in the clinical use. This is mainly due to the antagonism of sintering ability and suitable bioactivity. Competitive crystallization often prevents the generation of dense sintered bodies, especially for additive manufactured 3D structures. Previous studies of the fluoride-containing glass F3 have shown its potential to combine both sintering ability and suitable bioactivity. Furthermore, the occurring sintering blockade by surface crystallization of Na2CaSi2O6 was tunable by glass particle size. In this study the glasses F3, F3-Cu with 1 mol% CuO added at the expense of CaO and the well-known 13-93 were chosen to determine the influence of surface crystallization on 3D printed sinter bodies. For this purpose, grain size fractions in range of smaller 32 µm to 315 µm in fraction size of 6-20 µm were sieved from jaw crushed glass frit as well as glass cubes were cut from casted blocks for all glasses. Sintering behavior of both pressed and printed powder compacts was observed via heating microscopy. Crystallization was determined by DTA and crystallization progress was monitored on fractured sinter bodies and polished cubes via electron and laser scanning microscopy as well as with diffractometry. Depending on grain size the formation of crystalline support framework along former grain boundaries shows the capability to stabilize fully densified sinter bodies before softening. Beside of this, the generation of complex hierarchic porosity was possible as well. T2 - ICG Berlin 2022 CY - Berlin, Germany DA - 03.07.2022 KW - Bioactive Glass KW - Crystallization KW - Sintering KW - 3D printing PY - 2022 AN - OPUS4-55253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina T1 - Flüssigphasensinterung von Silber-Glas Dispersionen N2 - Silber-Glas Wechselwirkungen spielen eine wichtige Rolle zum Beispiel in Glas-haltigen Silberpasten, die in der Photovoltaik oder Mikroelektronik verwendet werden. Um ein besseres Verständnis der Vorgänge zu erhalten, werden niedrig-schmelzende, bleifreie X2O ZnO B2O3 Gläser (X = Li, Na, K und Rb, Abk.: LZB, NZB, KZB and RZB) zur Untersuchung der Pasten verwendet. Raman und Infrarot Spektroskopie zeigen, dass die Glasstruktur weitgehend vergleichbar ist, aber Unterschiede in der Bildung von Pentaboratgruppen in LZB und NZB oder Diboratgruppen in KZB und RZB auftreten. Die Anzahl an vierfach koordinierten Bor-Ionen (N4) sinkt mit zunehmendem Alkaliionenradius. Die Verringerung von N4 führt zu einer niedrigeren Glasübergangstemperatur in der Reihe LZB (472 °C) < NZB (465 °C) < KZB (460 °C) < RZB (449 °C). Zur Herstellung der Pasten wurde kommerzielles Silber-Pulver mit 30 Vol.-% Glas und Organik gemischt. Das Sinterverhalten der gepressten Pulver wurde mittels Erhitzungsmikrospie untersucht. Der Sinterbeginn der Pasten ist vergleichbar und korrespondiert mit den geringen Unterschieden der Viskosität bei vergleichbarer Partikelgröße der Gläser. In den Ag-KZB- und Ag-RZB-Pasten ist die Schwindung durch die stärker einsetzende Kristallisation im Vergleich zu LZB und NZB verzögert. T2 - AK Glasig-kristalline Multifunktionswerkstoffe CY - Aachen, Germany DA - 17.02.2022 KW - Sintern KW - Silber KW - Glas KW - Diffusion KW - Gefüge PY - 2022 AN - OPUS4-55735 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina T1 - Liquid phase sintering of alkali zinc borate glass-bearing silver pastes for applications in photovoltaics and microelectronics N2 - Liquid phase sintering of glass bearing silver pastes used in photovoltaics and microelectronics is poorly understood. In particular, the role of different network modifiers acting in the glass component and the question of the most suitable atmospheric oxygen level during sintering are still under considerable debate. To tackle these issues, low-melting and lead-free X2O-ZnO-B2O3 glasses with X = Li, Na, K and Rb (LZB, NZB, KZB and RZB) were prepared. Infrared spectroscopy showed that the glass structure was similar to each other, while an increase of tetrahedrally coordinated boron with increasing field strength of the alkali was evident. In turn, the glass transition temperature (from differential thermal analysis) increased in the order: RZB (449 °C) < KZB (460 °C) < NZB (465 °C) < LZB (472 °C). Powders of each glass were mixed with organics to receive silver-glass-pastes containing 30 vol% glass and these were subjected to heating microscopy in air. Although similar onset temperatures of sintering were recorded for Ag-NZB and Ag-LZB glass pastes, and for Ag-RZB paste and KZB-Ag-paste, respectively, differences in the crystallization behavior and final densification were observed between the former and the latter group. These were translated in terms of differences in silver dissolution and reprecipitation among the two groups. Further, running the experiments in nitrogen gas showed that sintering of all pastes was considerably hampered. The slow-down of the sinter kinetics was found to be in line with the assumed lower oxidation and dissolution of silver ions into the glass-forming liquid. T2 - 26th International Congress on Glass CY - Berlin, Germany DA - 03.07.2022 KW - Silver metallization paste KW - Sintering KW - Glass KW - Alkali zinc borate glasses KW - Viscosity KW - Structure PY - 2022 AN - OPUS4-55728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina T1 - In situ observation of silver precipitation in sodium zinc borate glass-forming melts N2 - Melting of Na2CO3-ZnO-B2O3 batches containing up to 16.8 wt% AgNO3 (5 mol% Ag2O in the target glass composition) was observed in situ by means of hot stage microscopy. In all batches metallic silver precipitation took place as most of the silver nitrate was reduced to metallic silver before Ag+ ions could be dissolved in the evolving borate melts. In turn, only traces of Ag+ (<300 ppmw) were dissolved in the sodium zinc borate glass melts under study. It is assumed that the oxidation to Ag+ was limited due to poor availability of reducible oxygen in the glass melts and presence of Na2O being a stronger base than Ag2O. Thus, the precipitated metallic silver formed droplets of different sizes. The larger droplets (d > 20 µm) were already settled at the bottom of the container and remained constant in size upon dwelling for 1 h at 1050 °C of about one hour and the subsequent cooling (45 K/min) to room temperature, whereas the smaller droplets (d < 20 µm) were mobile in the borate melt due to Marangoni and Stokes motion. For the latter droplets, coalescence was observed in situ. A growth of larger droplets at the expense of smaller ones, i.e., Ostwald ripening was also expected but could not be studied with the used experimental equipment. T2 - 26th International Congress on Glass CY - Berlin, Germany DA - 03.07.2022 KW - Glass melt KW - Silver KW - Sodium zinc borate glass KW - Hot stage microscopy KW - Precipitation PY - 2022 AN - OPUS4-55732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan T1 - Surface-Initiated Microstructure Formation in Glass Ceramics N2 - Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied by Rouxel in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation. T2 - 26th International Congress on Glass CY - Berlin, Germany DA - 03.07.2022 KW - Glass KW - Oriented surface crystallization KW - Surface energy KW - Bond energy KW - Nucleation mode PY - 2022 AN - OPUS4-56070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tielemann, Christopher T1 - Oriented Surface Crystallization N2 - Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied by Rouxel in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation. T2 - 26th International Congress on Glass CY - Berlin, Germany DA - 03.07.2022 KW - Glass KW - Surface energy KW - Crystal orientation PY - 2022 AN - OPUS4-56074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - Vacuum crack growth in silicate glasses N2 - Although the slow crack growth in glass is dominated by stress-corrosion phenomena, it also should reflect the underlaying intrinsic fracture behavior controlled by glass chemistry and structure. To investigate such underlaying phenomena, crack growth velocity in alkali silicate glasses was measured in vacuum across 10 orders of magnitude with double cantilever beam technique. Measured and literature crack growth data were compared with calculated intrinsic fracture toughness data obtained from Young’s moduli and theoretical fracture surface energy. Data analysis reveals slight correlation with the packing density and significant deviations from the intrinsic brittle fracture behavior. These deviations do not follow simple compositional trends. Two opposing processes may explain this finding: a decrease in the apparent fracture surface energy due to stress-induced chemical changes at the crack tip and its increase due to energy dissipation during fracture. T2 - 26th International Congress on Glass CY - Berlin, Germany DA - 03.07.2022 KW - Oxide glass KW - Fracture toughness KW - Fracture surface PY - 2022 AN - OPUS4-56485 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Chen, Y.-F. A1 - Contreras Jaimes, A. T1 - Datengetriebener Workflow für die beschleunigte Entwicklung von Glas (GlasDigital) N2 - Das Projekt GlasDigital wurde im allgemeinen vorgestellt, sowie die einzelnen Zwischenstände der verschiedenen Arbeitspakete aller Projektpartner präsentiert. Die allgemeine Porjektvorstellung ist auf deutsch. Die Zwischenstände der Arbeitsinhalte sind auf englisch. T2 - PMD Vollversammlung CY - Berlin, Germany DA - 03.11.2022 KW - Oxidglas KW - Robotische Glasschmelzanlage KW - ML KW - Ontologie KW - Digitaler Zwilling KW - Bildanalyse PY - 2022 AN - OPUS4-56491 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kilo, M. T1 - Glass Screening for the systematic development of new glasses N2 - Die technischen Möglichkeiten der robotischen Glasschmelzanlage der BAM werden vorgestellt. T2 - 26th International Conference on Glass CY - Berlin, Germany DA - 04.07.2022 KW - Material Digital PY - 2022 AN - OPUS4-56280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - Data-driven Workflow for Accelerated Glass Development (GlasDigital) N2 - As part of a joint project involving the Fraunhofer Institute for Silicate Research (ISC), the Friedrich Schiller University of Jena, the Clausthal University of Technology and the Federal Institute for Materials Research and Testing (BAM), digital tools are to be created for the development of new types of glass materials. Current processes for the production of glasses with improved properties are usually very cost- and energy-intensive due to the low degree of automation and are subject to long development cycles. The use of robotic synthesis processes in combination with self-learning machines is intended to overcome these problems in the long term. The development of new types of glass can then not only be accelerated considerably, but also be achieved with much less effort. In this talk, data generation via a robotic high-throughput glass melting system is presented, which should be the experimental basis for the ontology developed within the project GlasDigital. T2 - Materials Science and Engineering Congress (MSE 2022) CY - Darmstadt, Germany DA - 27.09.2022 KW - Oxidglas KW - Robotische Glasschmelzanlage PY - 2022 AN - OPUS4-56489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - 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 - 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 - CONF A1 - Lehmusto, Juho T1 - Initial oxidation of the refractory high-entropy superalloy AlMo0.5NbTa0.5TiZr N2 - In contrast to traditional alloys, which are typically based on a single dominant element, high-entropy alloys (HEAs) consist of five or more principal elements in roughly equal proportions. These complex alloys often exhibit superior characteristics compared to conventional alloys, including enhanced strength and hardness, exceptional wear resistance, high structural stability, and strong resistance to oxidation. Despite these promising characteristics, the vast compositional space of HEAs means that only a limited number have been thoroughly investigated for their mechanical and chemical behavior. One notable example is the refractory high-entropy superalloy AlMo0.5NbTa0.5TiZr, which represents a newly emerging class of materials. This alloy features a nanoscale microstructure composed of B2 and bcc phases, resulting in compressive strength at elevated temperatures that surpasses that of conventional Ni-based superalloys. Such performance offers potential benefits for improving turbine efficiency in aerospace and energy generation applications. However, the alloy’s microstructure is known to be sensitive to annealing. Specifically, its mechanical properties deteriorate when intragranular hexagonal Al-Zr-based intermetallic compounds form, likely due to issues with phase stability. On the other hand, the inclusion of Al has been shown to enhance oxidation resistance. Nevertheless, HEAs are also known to develop pronounced internal aging zones caused by diffusion during oxidation processes. These findings indicate a need for further investigation into the thermodynamic stability of this alloy. In addition, its oxidation behavior—both at the surface and within the material—remains incompletely understood. This ongoing research explores the oxidation behavior of the AlMo0.5NbTa0.5TiZr alloy at temperatures ranging from 800 °C to 1000 °C. The influence of water vapor on the oxidation process is also examined. Ultimately, the goal is to integrate insights into the alloy’s structural, mechanical, and chemical characteristics at high temperatures. T2 - Gordon Research Conference - High Temperature Corrosion CY - New London, United States DA - 16.07.2023 KW - High-Entropy superalloy KW - Phase stability KW - Microstructural evolution KW - Oxidation behavior KW - High-Temperature Performance PY - 2023 AN - OPUS4-63851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madia, Mauro T1 - Damage Tolerant Approach in Additively Manufactured Metallic Materials N2 - Damage tolerance counts as one of the most widespread approach to fatigue assessment and surely as one of the most promising in understanding the process-structure-property-performance relationships in additively manufactured metallic materials. Manufacturing defects, surface roughness, microstructural features, short and long crack fatigue propagation, residual stresses and applied loads can be taken into consideration in a fracture mechanics-based fatigue assessment. Many aspects are crucial to the reliable component life prediction. Among those a prominent role is played by an accurate measurement and modelling of the short crack fatigue behavior, and reliable statistical characterization of defects and residual stresses. This work aims at addressing the issues related to both experimental testing, fatigue and fatigue crack propagation, and fracture mechanics-based modelling of fatigue lives. Examples will be provided on an additively manufactured AISI 316 L. T2 - TMS2021 VIRTUAL CY - Online meeting DA - 15.03.2021 KW - AISI 316L KW - Additive Manufacturing KW - Damage Tolerance KW - Microstructure KW - Defects KW - Residual Stress PY - 2021 AN - OPUS4-52293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Böhning, Martin T1 - Environmental Stress Cracking in PE-HD – Assessment of Crack Propagation and Mechanisms by Optical Methods N2 - Slow crack growth (SCG) under the influence of external fluid media, usually termed environmental stress cracking (ESC), is still one of the most frequent origins of severe damage and failure of polymeric materials. For polyethylene (PE) this is relevant for mass products, like bottles for consumer products, but also for high-performance materials for pipes or industrial packaging, including containers for chemicals and other dangerous goods. Especially for high-density polyethylene (PE-HD) the susceptibility to SGC and ESC is depending on the complex interplay between molecular weight and architecture and the resulting semicrystalline morphology, especially the formation of tie-molecules. A reliable assessment of the resistance against this damage phenomenon is essential for demanding as well as safety-critical applications and has to take into account suitable testing methodologies and conditions in combination with environmental media reflecting the properties representative for typical fillings and relevant components causing ESC. In this context a better understanding of different influencing factors, such as sorption, swelling or surface activity is necessary together with a detailed characterization of different stages of crack propagation and underlying mechanisms. Therefor well-established testing methods, such as the Full Notch Creep Test (FNCT), were complemented by detailed fracture surface analysis using e.g. LSM and SEM in combination with a time-dependent optical monitoring of the progressing crack growth. For the crack growth also the ratio of fibrillated craze zone to crack opening is important for the deeper understanding of crack propagation and related material parameters which can be additionally addressed by X-ray computed tomography. T2 - 34th Polymer Degradation Disscussion Group (PDDG) Conference CY - Dubrovnik, Croatia DA - 12.06.2023 KW - Polyethylen KW - Full Notch Creep Test KW - Environmental Stress Cracking KW - Fracture Surface Analysis PY - 2023 AN - OPUS4-57711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina T1 - An overview of structural, physical and thermal properties of low melting zinc and lead borate glasses N2 - Low melting zinc borate glasses awake interest to replace lead borate glasses in the silver metallization pastes for solar cells or microelectronics. In the current study, characteristic properties of alkali zinc borate glasses (X2O-ZnO-B2O3, X = Li, Na, K, Rb) were compared to an earth alkali zinc borate glass (CaO-ZnO-B2O3). Additionally, zinc oxide is partially substituted by lead oxide or cooper oxide in the borate glasses (Li2O-PbO-B2O3, Na2O ZnO CuO-B2O3). The alkali zinc borate glasses indicate less differences in Raman spectra, and thus in structural properties, in comparison to the Ca and Pb ions influence. LPbB (Tg = 401 °C) has a lower viscosity than LZB (Tg = 468 °C) and CaZB has the highest glass transition temperature (Tg = 580 °C). The Angell plot for the alkali zinc borate glasses shows a high fragility m = 80. Besides Tg, the density measured by means of the Archimedean principle, molar volume, and coefficient of thermal expansion (CTE) of the glasses were investigated. Trends could be found according to alkali ions or intermediate oxides. The density increases with decreasing alkali ion size from KZB (2.632 g/cm3) to LZB (2.829 g/cm3) and increases from LZB to LPbB (3.764 g/cm3). CTE ranges between 7.09 10-6 K-1 for CaZB and 11.5 10 6 K 1 for KZB and RZB. The differential thermal analysis (DTA) and X ray diffraction (XRD) indicate crystallization of various crystalline phases during heating with 5 K/min in most cases. T2 - 94. Glastechnische Tagung CY - Online meeting DA - 10.05.2021 KW - Borate glasses KW - Glass structure KW - Viscosity KW - Young´s Modulus KW - Alkali ions PY - 2021 AN - OPUS4-52867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yesilcicek, Yasemin A1 - Haas, S. A1 - Suárez Ocano, Patricia A1 - Zaiser, E. A1 - Hesse, René A1 - Többens, D. M. A1 - Glatzel, U. A1 - Manzoni, Anna Maria T1 - Controlling Lattice Misfit and Creep Rate Through the γ' Cube Shapes in the Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex Alloy with Hf and W Additions N2 - Trace elements play an important role in the fine-tuning of complex material properties. This study focuses on the correlation of microstructure, lattice misfit and creep properties. The compositionally complex alloy Al10Co25Cr8Fe15Ni36Ti6 (in at. %) was tuned with high melting trace elements Hf and W. The microstructure consists of a γ matrix, γ' precipitates and the Heusler phase and it is accompanied by good mechanical properties for high temperature applications. The addition of 0.5 at.% Hf to the Al10Co25Cr8Fe15Ni36Ti6 alloy resulted in more sharp-edged cubic γ′ precipitates and an increase in the Heusler phase amount. The addition of 1 at.% W led to more rounded γ′ precipitates and the dissolution of the Heusler phase. The shapes of the γ' precipitates of the alloys Al9.25Co25Cr8Fe15Ni36Ti6Hf0.25W0.5 and Al9.25Co25Cr8Fe15Ni36Ti6Hf0.5W0.25, that are the alloys of interest in this paper, create a transition from the well-rounded precipitates in the alloy with 1% W containing alloy to the sharp angular particles in the alloy with 0.5% Hf. While the lattice misfit has a direct correlation to the γ' precipitates shape, the creep rate is also related to the amount of the Heusler phase. The lattice misfit increases with decreasing corner radius of the γ' precipitates. So does the creep rate, but it also increases with the amount of Heusler phase. The microstructures were investigated by SEM and TEM, the lattice misfit was calculated from the lattice parameters obtained by synchrotron radiation measurements. KW - High entropy alloy KW - Lattice misfit KW - Creep KW - Transmission electron microscopy KW - X-ray diffraction PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565655 DO - https://doi.org/10.1007/s44210-022-00009-1 SP - 1 EP - 9 PB - Springer AN - OPUS4-56565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohring, Wencke A1 - Karafiludis, Stephanos A1 - Manzoni, Anna Maria A1 - Laplanche, G. A1 - Schneider, M. A1 - Stephan-Scherb, Christiane T1 - High-Temperature Corrosion of High- and Medium-Entropy Alloys CrMnFeCoNi and CrCoNi Exposed to a Multi-Oxidant Atmosphere H2O–O2–SO2 N2 - AbstractThe high-temperature corrosion behaviors of the equimolar CrCoNi medium-entropy alloy and CrMnFeCoNi high-entropy alloy were studied in a gas atmosphere consisting of a volumetric mixture of 10% H2O, 2% O2, 0.5% SO2, and 87.5% Ar at 800 °C for up to 96 h. Both alloys were initially single-phase fcc with a mean grain size of ~ 50 μm and a homogeneous chemical composition. The oxide layer thickness of CrMnFeCoNi increased linearly with exposure time while it remained constant at ~ 1 μm for CrCoNi. A Cr2O3 layer and minor amounts of (Co,Ni)Cr2O4 developed on the latter while three oxide layers were detected on the former, i.e., a thin and continuous chromium rich oxide layer at the oxide/alloy interface, a dense (Mn,Cr)3O4 layer in the center and a thick and porous layer of Mn3O4 and MnSO4 at the gas/oxide interface. Additionally, a few metal sulfides were observed in the CrMnFeCoNi matrix. These results were found to be in reasonable agreement with thermodynamic calculations. KW - high entropy alloys KW - corrosion KW - oxidation KW - scanning electron microscopy KW - sulfidation KW - CrMnFeCoNi PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594189 DO - https://doi.org/10.1007/s44210-023-00026-8 SP - 1 EP - 17 PB - Springer Science and Business Media LLC AN - OPUS4-59418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Weinel, Kristina A1 - Hahn, Marc Benjamin A1 - Lubk, Axel A1 - Feng, Wen A1 - Martinez, Ignacio Gonzalez A1 - Büchner, Bernd A1 - Agudo Jácome, Leonardo T1 - Electron-beam-induced modification of gold microparticles in an SEM N2 - Electron-beam-induced conversion of materials in a transmission electron microscope uses 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. 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 developed to increase the versatility and efficiency of the technique. 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. KW - Scanning electron microscopy KW - Electron-beam-induced modification KW - Heat transfer KW - Gold microparticles KW - Nanoparticles synthesis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609513 UR - https://arxiv.org/html/2408.02409v1 SP - 1 EP - 9 AN - OPUS4-60951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prabhakara, Prathik T1 - Ein synergistischer Ansatz zur Charakterisierung anisotroper Materialien mit Hilfe von Ultraschall und Mikrostrukturanalyse N2 - Es wird eine Studie zur Charakterisierung eines anisotropen Stahls vorgestellt, bei der Ultraschalluntersuchungen mit Mikrostrukturanalysen verbunden werden. Das Material weist hohe Festigkeit und Korrosionsbeständigkeit auf, zugleich ist mit anisotropen Eigenschaften die mechanischen und betrieblichen Eigenschaften beeinflussen zu rechnen. Vorläufige Ergebnisse lassen vermuten, dass weitere Untersuchungen notwendig sind, um die Fähigkeiten und Grenzen des Materials genau zu bestimmen. Es wird ein systematischer Ansatz mit Array- Prüfköpfen, Time-of-Flight Diffraction (TOFD) Technik und mikrostrukturellen Untersuchungen angewendet, um die Wechselwirkung zwischen Anisotropie und Mikrostruktur des Stahls zu analysieren. Ultraschallprüfungen mit der TOFD-Technik und in Tauchtechnik liefern Einblicke in das anisotrope Verhalten des Werkstoffes, einschließlich entsprechenden Kornorientierung, Dämpfung und Schallgeschwindigkeitsvariation. Diese Messungen führen in Verbindung mit mikrostrukturellen Analysen zu einem tieferen Verständnis des Materialverhaltens. Unser Hauptziel ist es, ein Framework zu erstellen, welches die Ultraschallantwort anisotroper Materialien mit ihren mikroskopischen Struktureigenschaften verbindet. Die vorgestellte Methodik ermöglicht eine zerstörungsfreie und zügige Bewertung der Materialintegrität, was besonders bei der Anwendung von Hochleistungsmaterialien relevant ist. Durch diesen integrativen Ansatz werden verschiedener Charakterisierungsmethoden kombiniert, um ein umfassenderes Materialverständnis zu erreichen. T2 - DGZfP-Jahrestagung 2024 CY - Osnabrück, Germany DA - 06.05.2024 KW - Ultrasonic Testing KW - Time-offlight Diffraction (TOFD) KW - Microstructure Analysis KW - Non-Destructive Testing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600122 UR - https://www.ndt.net/?id=29535 AN - OPUS4-60012 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Roving-Alterung und mechanische Eigenschaften N2 - Im statistischen Mittel steht eine Windkraftanlage (WKA) in Deutschland alle 6 Jahre wegen eines Schadens an den Rotorblättern und verursacht Kosten von 20k€-40k€ infolge Ertragsausfall und Reparaturkosten. Bei über 30.000 WKA in Deutschland verursacht dies jährlichen Kosten von 100-200 Mio. €. Zu 70% sind die Ursachen Fertigungsfehler. Diesem Themenkomplex widmet sich FB-5.3 in Kooperation mit FBs der Zerstörungsfreien Prüfung (Abt. 8) schon seit Jahren. Im aktuellen Projekt geht es um einen vorzeitigen Verschleiß der Rotorblätter infolge der Verwendung gealterter Glasfaser-Rovings. (GF). Die Entwicklung moderner Windkraftanlagen hatte in Europa seinen Ursprung in den 90er Jahren. OEMs und GF-Hersteller waren dicht beisammen. Die Globalisierung des Marktes führt heute zu einer weltweiten Verschiffung der GF in feucht-warmen Containern. Je nach Beschaffenheit (Chemie) der Schlichten (Oberflächenbehandlung) von GF können diese stark altern (Hydrolyse-Effekte) und die Festigkeit kann im Bauteil um bis zu 50% abgemindert sein. In einer Kooperation mit der Rotorblattallianz, einem Zusammenschluss der OEMs, Halbzeugherstellern und Forschungsinstituten, wurden schon vor 5 Jahren in einem Forschungsprojekt (FB-5.3; VH 5538) die chemischen Mechanismen der Alterung exemplarisch für eine Glasfaser-Roving-Type aufgeklärt. Im aktuellen Projekt (FB-5.3; VH 5304) wird ein beschleunigtes Alterungsverfahren (erhöhte Temperatur und Feuchte) am Roving im un-impregnierten Zustand entwickelt und die Festigkeit nachfolgend nach Einbettung in eine Epoxid-Harz-Matrix bestimmt. Je nach Alterungszustand zeigt sich eine Abnahme der Zwischenfaserbruchfestigkeit von bis zu 50%. Nicht alle Glasfaser-Roving-Typen zeigen diesen Effekt. Es ist gelungen für OEMs und Halbzeughersteller ein handhabbares Verfahren zur innerbetrieblichen Qualitätssicherung zu entwickeln, da die wenigsten Firmen über komplexe Analyseverfahren, wie an der BAM, verfügen. T2 - Composite United - AG Faserverbund in der Windenergie CY - Braunschweig, Germany DA - 09.05.2023 KW - Faserkunststoffverbunde KW - Windenergie KW - Alterung PY - 2023 AN - OPUS4-58409 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago T1 - Experimentelle Ermittlung zyklischer R-Kurven in additiv gefertigtem AISI 316L Stahl N2 - Diese Untersuchung beschäftigt sich mit der Charakterisierung von Kurzrisswachstum in mittels Laser-Pulverbett-Verschmelzen (LPBF - Laser Powder Bed Fusion) hergestelltem rostfreien austenitischen Stahl. Spezifischer wird die Ermittlung zyklischer R-Kurven untersucht. Diese beschreiben den Aufbau des Widerstands gegen Ermüdungsrisswachstum - d.h. des Schwellenwertes - aufgrund von Rissschließeffekten bei physikalisch kurzen Rissen. Mit Hilfe der zyklischen R-Kurven kann die Fähigkeit eines Bauteils, physikalisch kurze Risse zu arretieren, charakterisiert werden. Wir verfügen damit über eine Schnittstelle zwischen klassischer Ermüdung und Bruchmechanik. Das ist gerade auch für additiv gefertigte (AM – Additive Manufacturing) Materialien von Interesse. Diese weisen prozessintrinsische Defekte auf, die als Initiierungsstellen kurzer Ermüdungsrisse agieren. Im Rahmen der experimentellen Untersuchungen wurden zyklische R-Kurven für konventionellen und LPBF AISI-316L-Stahl ermittelt. Insbesondere wurde der Einfluss verschiedener Wärmebehandlungen (WB1: 450°C, WB2: 800°C und WB3: 900°C) auf das Wachstumsverhalten physikalisch kurzer Risse im LPBF-Material untersucht. Aufgrund hoher Eigenspannungen war die Ermittlung des Kurzrisswachstumsverhaltens bei WB1 nicht möglich. Für WB2 und WB3 ergaben sich sehr unterschiedliche zyklische R-Kurven. Untersuchungen der Eigenspannungen, der Bruchfläche (insbesondere der Rauheit) und der Mikrostruktur sollen die Ursachen für das unterschiedliche Verhalten erklären. Die Ergebnisse werden mit den Verhältnissen in konventionellem Material verglichen. T2 - Tagung des Arbeitskreises Bruchmechanik und Bauteilsicherheit CY - Online meeting DA - 18.02.2021 KW - Additive Manufacturing KW - Zyklische R-Kurve KW - Ermüdungsriss KW - L-PBF KW - 316L PY - 2021 AN - OPUS4-52250 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella A1 - Ulbricht, Alexander A1 - Evans, Alexander A1 - Altenburg, Simon A1 - Ehlers, Henrik A1 - Hilgenberg, Kai A1 - Mohr, Gunther T1 - Monitoring additive manufacturing processes by using NDT methods N2 - In this presentation we discuss the online monitoring of metallic AM parts produced by the Laser Powder Bed Fusion (LPBF) process by using optical, thermographic and electromagnetic methods. In a first approach we present the detection of defects generated during the process and discuss how to improve these methods for the optimization of design and production of metallic AM parts. T2 - ABENDI - Workshop CY - Online meeting DA - 19.11.2020 KW - Additive Fertigung PY - 2020 AN - OPUS4-52042 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 - GEN A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Rosalie, Julian T1 - Small-angle scattering data analysis round robin - Anonymized results, figures and Jupyter notebook N2 - The intent of this round robin was to find out how comparable results from different researchers are, who analyse exactly the same processed, corrected dataset. This zip file contains the anonymized results and the jupyter notebook used to do the data processing, analysis and visualisation. Additionally, TEM images of the samples are included. KW - Round robin KW - Small-angle scattering KW - Data analysis PY - 2023 DO - https://doi.org/10.5281/zenodo.7509710 PB - Zenodo CY - Geneva AN - OPUS4-56803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella T1 - Monitoring additive manufacturing N2 - Additive manufacturing (AM) processes allow a high level of freedom in designing and producing components for complex structures. They offer the possibility of a significant reduction of the process chain. However, the large number of process parameters influence the structure and the behavior of AM parts. A thorough understanding of the interdependent mechanisms is necessary for the reliable design and production of safe AM parts. In this presentation we discuss the online monitoring of metallic AM parts produced by the Laser Powder Bed Fusion (LPBF) process by using optical, thermographic and electromagnetic methods. In a first approach we present the detection of defects generated during the process and discuss how to improve these methods for the optimization of design and production of metallic AM parts. T2 - Conaendi&IEV 2021 CY - Online meeting DA - 10.03.2021 KW - Additive Fertigung PY - 2021 AN - OPUS4-52241 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gogula, Shravya A1 - Bornhöft, H. A1 - Wondraczek, L. A1 - Sierka, M. A1 - Diegeler, A. A1 - Müller, Ralf A1 - Deubener, J. T1 - Optical Real-Time Castability Evaluation for High-Throughput Glass Melting N2 - A novel optical real-time method for evaluating the castability of glass forming melts for laboratory furnaces is presented. The method is based on the analysis of top view images of the melt surface inside the crucible during melting after being subjected to a small mechanical impulse. In this way, the melt surface is excited to oscillate. The difference in contrast between two images taken in quick succession scales with the viscosity, with a larger diffe­rence occurring at lower viscosities. The method is designed as an instrument for the in-line evaluation of the castability for a high-throughput glass melting system as part of the joint project “GlasDigital” in the framework of the German Platform Material Digital initiative but is applicable to other laboratory furnaces as well. KW - Optical Real-Time Castability Check KW - Image Analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618659 DO - https://doi.org/10.52825/glass-europe.v2i.1359 VL - 2 SP - 83 EP - 93 AN - OPUS4-61865 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 - Welter, T. A1 - Müller, Ralf A1 - Deubener, J. A1 - Marzok, Ulrich A1 - Reinsch, Stefan T1 - Hydrogen Permeation Through Glass N2 - Physical storage of gaseous hydrogen under high-pressure in glassy micro-containers such as spheres and capillaries is a promising concept for enhancing safety and the volumetric capacity of mobile hydrogen storage systems. As very low permeation through the container wall is required for storage of compressed hydrogen, development of glasses of minimal hydrogen permeability is needed. For this purpose, one has to understand better the dependence of hydrogen permeability on glass structure. The paper points out that minimizing the accessible free volume is as one strategy to minimize hydrogen permeability. Based on previously measured and comprehensive literature data, it is shown that permeation is independently controlled by ionic porosity and network modifier content. Thus, ionic porosity in modified and fully polymerized networks can be decreased equally to the lowest hydrogen permeability among the glasses under study. Applying this concept, a drop of up to 30,000 with respect to the permeation of hydrogen molecules through silica glass is attainable. KW - Ionic porosity KW - hydrogen storage KW - Glass KW - Permeability KW - Solubility KW - Diffusivity PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513927 DO - https://doi.org/10.3389/fmats.2019.00342 VL - 6 SP - Article 342 AN - OPUS4-51392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heuser, Lina A1 - Nofz, Marianne A1 - Müller, Ralf T1 - Alkali and alkaline earth zinc and lead borate glasses: Sintering and crystallization N2 - Glasses in the systems Me2O-ZnO-B2O3 with Me = Li, Na, K, Rb (MeZB), Na2O-ZnO-CuO-B2O3 (NZCuB), CaO-ZnO-B2O3 (CaZB), and Li2O-PbO-B2O3 (LPbB) as a reference, were studied by differential thermal analysis, dilatometry, rotational viscometry, and heating microscopy. A decrease of viscosity and sintering range was found with decreasing number of fourfold coordinated boron. The viscosity of the alkali zinc borate glasses varies only slightly. LPbB and CaZB stand out by their reduced and increased viscosities, respectively. Sodium, potassium, and calcium zinc borate glasses possess a fragility above 76. All glasses were sintered to full density before crystallization. Mostly binary zinc borate phases govern crystallization. A ternary crystalline phase was detected only in the potassium containing sample. The Weinberg glass stability parameter ranges between 0.07 and 0.12. This is caused by the presence of several crystalline phases and varying melting points of even the same crystalline phase in different glass matrices. KW - Alkali zinc borate glasses KW - Lead borate glasses KW - Viscosity KW - Sintering KW - Crystallization KW - Fragility PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556128 DO - https://doi.org/10.1016/j.nocx.2022.100116 SN - 2590-1591 VL - 15 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-55612 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gomes Fernandes, Roger A1 - Al-Mukadam, Raschid A1 - Bornhöft, Hansjörg A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Selle, Susanne A1 - Deubener, Joachim T1 - Viscous Sintering of Acid Leached Glass Powders N2 - The process of viscous flow sintering is a phenomenon that is closely linked to the surface properties of the glass particles. In this work, we studied the extreme case of acid-leaching of soda-lime-silicate glass beads of two different particle size distributions and its effects on non-isothermal viscous sintering of powder compacts. Depth profiling of the chemical composition after leaching revealed a near-surface layer depleted in alkali and alkaline earth ions, associated with concurrent hydration as mass loss was detected by thermogravimetry. Heating microscopy showed that acid treatment of glasses shifted the sinter curves to higher temperatures with increasing leaching time. Modelling of the shrinkage with the cluster model predicted a higher viscosity of the altered surface layer, while analysis of the time scales of mass transport of mobile species (Na+, Ca2+ and H2O) during isochronous sintering revealed that diffusion of Na+ can compensate for concentration gradients before sintering begins. Also, exchanged water species can diffuse out of the altered layer, but the depletion of Ca2+ in the altered surface layer persists during the sinter interval, resulting in a glass with higher viscosity, which causes sintering to slow down. KW - Glass powder KW - Viscous sintering KW - Acid-leaching KW - Sinter retardation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589008 DO - https://doi.org/10.52825/glass-europe.v1i.681 VL - 1 SP - 37 EP - 53 AN - OPUS4-58900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinsch, Stefan A1 - Welter, T. A1 - Müller, Ralf A1 - Deubener, J. T1 - Hydrogen Permeability of Tectosilicate Glasses for Tank Barrier Liners N2 - The permeation of hydrogen gas was studied in meta-aluminous (tectosilicate) glass powders of Li2O×Al2O3×SiO2 (LAS), Na2O×Al2O3×SiO2 (NAS) and MgO×Al2O3×SiO2 (MAS) systems by pressure loading and vacuum extraction in the temperatures range 210–310 °C. With this method, both the solubility S and the diffusivity D were determined, while the permeability was given by the product SD. For all glasses, S was found to decrease with temperature, while D increased. Since the activation energy of diffusion of H2 molecules exceeded that of dissolution, permeation increased slightly with temperature. When extrapolated to standard conditions (25 °C), the permeability of tectosilicate glasses was found to be only 10-22–10-24 mol H2 (m s Pa)-1, which is 8–10 magnitudes lower than most polymers. Thin glass liners of these compositions are expected to be the most effective barrier for tanks of pressurised hydrogen. KW - Hydrogen permeation KW - Aluminosilicate glasses KW - Hydrogen storage tank KW - Glass liner PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587284 DO - https://doi.org/10.52825/glass-europe.v1i.425 VL - 1 SP - 1 EP - 11 AN - OPUS4-58728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heuser, Lina T1 - Silver - alkali borate glass pastes N2 - Network modifier ions can decisively influence properties and structure of low melting alkali-zinc-borate glasses and thus cause complex effects on the liquid phase sintering of silver-glass metallization pastes. This effect was studied for X2O-ZnO-B2O3 (X = Li, Na, Rb) glasses for silver-glass metallization pastes. Viscosity and the glass transition temperature, Tg, were measured with rotational viscometry and dilatometry. Dried model pastes with 30 vol% LZB, NZB or RZB glass were prepared for sintering studies by means of heating microscopy measuring the silhouette area shrinkage of uniaxially pressed powder compacts during heating at 5 K/min. For comparison, the silhouette area shrinkage of pure glass and silver powder compacts were determined. Glass-silver wetting was investigated during heating of bulk glass cylinders placed on silver substrates. Glass RZB turned out to have the lowest viscosity among the glasses under study. Its glass transformation temperature, Tg, was found at 444 °C and it caused the lowest sintering onset for its glass and paste powder compacts. Slightly increased values of Tg were found for NZB and LZB (468 °C and 466 °C, respectively) and a slightly retarded sintering was found for both paste powder compacts. These results indicate that liquid phase sintering of silver-glass pastes under air atmosphere is mainly influenced by glass viscosity. T2 - GLASS MEETING 2020 CY - Online meeting DA - 07.12.2020 KW - Silver-glass metallization paste KW - Sintering KW - Alkali ions KW - Viscosity KW - Silver precipitates PY - 2020 AN - OPUS4-52871 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf T1 - GlasDigital: Data-driven workflow for accelerated glass development N2 - lasses stand out by their wide and continuously tunable chemical composition and large variety of unique shaping techniques making them a key component of modern high technologies. Glass development, however, is still often too cost-, time- and energy-intensive. The use of robotic melting systems embedded in an ontology-based digital environment is intended to overcome these problems in future. As part of the German research initiative MaterialDigital, the joint project GlasDigital takes first steps in this direction. The project consortium involves the Fraunhofer ISC in Würzburg, the Friedrich Schiller University Jena (OSIM), the Clausthal University of Technology (INW), and the Federal Institute for Materials Research and Testing (BAM, Division Glasses) and aims to combine all main basic components required for accelerated data driven glass development. For this purpose, a robotic high throughput glass melting system is equipped with novel inline sensors for process monitoring, machine learning (ML)-based, adaptive algorithms for process monitoring and optimization, novel tools for high throughput glass analysis and ML-based algorithms for glass design, including software tools for data mining as well as property and process modelling. The talk gives an overview how all these tools are interconnected and illustrates their usability with some examples. T2 - HVG-DGG Fachausschuss I CY - Jena, Germany DA - 03.11.2023 KW - Glass KW - Robotic melting KW - Ontologie KW - Simulation KW - Workflow KW - Data Space PY - 2023 AN - OPUS4-60383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suárez Ocaño, Patricia A1 - Agudo Jácome, Leonardo T1 - Oxidation Behavior of the AlMo0.5NbTa0.5TiZr Chemically Complex Alloy N2 - The chemically complex alloys that contain mostly refractory elements (rCCAs), may be highly resistant to heat and load, which makes them attractive candidates for use at extremely high temperatures associated with technological applications such as aeroengine turbines. However, the oxidation behavior remains an emerging field within the CCA community. The fully heat treated AlMo0.5NbTa0.5TiZr rCCA contains a dual-phase microstructure that resembles the γ/ γ’ pattern of the well-known Ni-base superalloys, however with a continuous Al-Zr-Ti-rich B2 ordered matrix embedding Mo-Nb-Ta-rach bcc precipitates. The question thus arises what is the oxidation behavior of this rCCA alloy? In this study, this question is addressed via in situ and ex situ X-ray diffraction (XRD) in dry and humid air in the 800–1000 °C regime. Electron microscopic investigations complement the findings. In situ synchrotron experiments were carried out at the KMC2 beamline of the Helmholtz Zentrum Berlin (HZB), with a wavelength of 1.5418 Å at 800 and 950 °C under dry and humid (≈ 40% rH, laboratory air) air for 12 h. Scanning and transmission electron microscopy was performed before and after exposure to spatially resolve the scale development ex situ. In general, 12 h exposure led to an oxide scale which internal oxidation reaches several tens of microns, and which is dominated by Zr-, Ti- and Mo-containing oxides although aluminum oxide was also always present. Main differences are observed between temperatures, while the humidity played a lesser role. T2 - International Conference on High Entropy Materials (ICHEM) 2023 CY - Knoxville, TN, USA DA - 18.06.2023 KW - High entropy superalloy KW - High temperature oxidation KW - In situ synchrotron diffraction KW - Electron microscopy PY - 2023 AN - OPUS4-63857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria T1 - Effect of a mixed atmosphere H2O-O2-SO2 on the oxidation kinetics and phase formation on CrMnFeCoNi and CrCoNi N2 - The high-temperature corrosion behaviors of the equimolar CrCoNi medium- and CrMnFeCoNi high-entropy alloy were studied in a gas atmosphere consisting of a volumetric mixture of 10% H2O, 2% O2, 0.5% SO2, and 87.5% Ar at 800 °C for up to 96 h. Both alloys were initially single-phase fcc structured and showed a mean grain size of ~50 µm and a homogeneous chemical composition. The oxide layer thickness of the Cantor alloy CrMnFeCoNi increased linearly with exposure time while it remained constant at ~1 µm for CrCoNi. A Cr2O3 layer and minor amounts of (Co,Ni)Cr2O4 developed on CrCoNi while three layers were detected on the Cantor alloy. These layers were a thin and continuous chromium rich oxide layer at the oxide/alloy interface, a dense (Mn,Cr)3O4 layer in the center and a thick and porous layer of Mn3O4 and MnSO4 at the gas/oxide interface. Additionally, a few metal sulfides were observed in the CrMnFeCoNi matrix. These results were found to be in reasonable agreement with thermodynamic calculations. T2 - ICHEM 2023 CY - Knoxville, TN, USA DA - 18.06.2023 KW - High entropy alloys KW - Chemically complex alloys KW - Corrosion KW - Mixed gas atmosphere PY - 2023 AN - OPUS4-57776 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria T1 - Early Material Damage in Equimolar CrMnFeCoNi in Mixed Oxidizing/Sulfiding Hot Gas Atmosphere N2 - The challenges to use more varied fuels at medium and high temperatures above 500 °C need to be addressed by tuning the materials towards a better resistance against increased corrosion. As a first step the corrosion processes need to be better understood, especially in the case of the unavoidable and highly corrosive sulfur-based gases. In this work oxidation/sulfidation of an equimolar CrMnFeCoNi high entropy alloy is studied at an early stage after hot gas exposure at 600 °C for 6 h in 0.5% SO2 and 99.5% Ar. The oxidation process is studied by means of x-ray diffraction, scanning and transmission electron microscopy and supported by thermodynamic calculations. It is found that the sulfur does not enter the bulk material but interacts mainly with the fast-diffusing manganese at grain boundary triple junctions at the alloy surface. Sub-micrometer scaled Cr-S-O rich phases close to the grain boundaries complete the sulfur-based phase formation. The grains are covered in different Fe, Mn and Cr based spinels and other oxides. T2 - Priority Programme (Schwerpunktprogramm) Compositionally Complex Alloys - High Entropy Alloys (SPP CCA - HEA) CY - Bayreuth, Germany DA - 12.07.2022 KW - High entropy alloy KW - Corrosion KW - Sulfiding KW - Cantor alloy KW - Transmission electron microscopy PY - 2022 AN - OPUS4-55395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lehmusto, Juho T1 - The effect of humidity on the initial oxidation of the refractory high-entropy superalloy AlMo0.5NbTa0.5TiZr N2 - Unlike conventional alloys, which typically consist of one main element, high-entropy alloys (HEAs) contain five or more principal elements. When compared with conventional alloys, HEAs may possess desirable properties such as improved strength/hardness, remarkable wear resistance, high structural stability, and notable oxidation resistance. However, due to the numerous possibilities of alloy composition, only a small fraction of HEAs has been characterized in terms of their mechanical and chemical properties. A refractory high-entropy superalloy AlMo0.5NbTa0.5TiZr, with its superalloy-like microstructure, belongs to the first group of a subclass of such Al-containing refractory HEAs that has recently drawn attention. The alloy has a nanoscale microstructure consisting of B2 and bcc phases, enabling high-temperature compressive strengths beyond conventional Ni-based alloys. This feature could improve turbine efficiency in the aerospace and power production industries. However, the microstructure has been reported to be sensitive to heat treatment after which it loses mechanical performance when the intragranular hexagonal Al-Zr-based intermetallic forms. This might be connected with the phase stability in the material. Then again, the addition of Al has been reported to improve the oxidation resistance of the material, but also that HEA materials tend to show pronounced zones of internal aging caused by diffusion during oxidation. These previous results imply that further research on the thermodynamic stability of the alloy is required. Furthermore, the oxidation behavior (both external and internal) and the role of humidity in the process are not fully understood. With such a multi-component material, the grain boundaries are expected to play a key role in the oxidation process, serving as short-circuit pathways for diffusion. To shed more light on the oxidation behavior of the AlMo0.5NbTa0.5TiZr alloy, experiments were carried out for 24 hours at 800 °C under both dry (21% O2 + 79% N2) and humid (8% O2 + 74% N2 + 18% H2O) atmospheres. After the experiments, the samples were characterized with XRD, SEM-EDS, and EPMA. The alloy oxidized rapidly under both studied atmospheres, resulting in a visibly oxidized region with a thickness of around 1.5 microns (dry) and 3.8 microns (humid). The porosity of the oxidized regions differs from one another: a thin layer of pores was detected in the outermost part of the oxidized zone under dry conditions, whereas the pores were distributed throughout the oxidized zone under humid conditions. Furthermore, the presence of humidity affected the phase formation. The grain boundaries, while still recognizable, differed visually from the grains in the as-received material, indicating the active role of grain boundaries during the oxidation. In addition, in the exposed samples, cracks along the grain boundaries were detected. Interestingly, cracks were also located within the grains. This could originate from the diffusion of species from the grains to the grain boundaries, which has changed the composition of grains. As a consequence, cracks formed most likely during cooling due to the Pilling-Bedworth effect. The formation of cracks suggested that the macro-scale homogeneity of the material may change during operation at high temperatures due to the active grain boundaries. T2 - High Temperature Corrosion and Oxidation 2023 Workshop CY - Marktheidenfeld, Germany DA - 25.09.2023 KW - High-Entropy superalloy KW - Oxidation behavior KW - Grain boundaries KW - Microstructure Evolution KW - High-Temperature Performance PY - 2023 AN - OPUS4-63850 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wehmann, N. A1 - Lenting, C. A1 - Stawski, T. M. A1 - Agudo Jácome, Leonardo T1 - Anhydrite formation in planetary surface environments - The case of the Atacama Desert N2 - Gypsum (CaSO4∙2H2O), bassanite (CaSO4∙0.5H2O), and anhydrite (CaSO4) are essential evaporite minerals for the evolution of hyper-arid surface environments on Earth and Mars (Voigt et al. 2019; Vaniman et al. 2018). The formation mechanism of especially anhydrite has been a matter of scientific debate for more than a century (van’t Hoff et al. 1903). To date, there exists no model that can reliably predict anhydrite formation at earth’s surface conditions. While thermodynamics favor its formation, it is hardly achieved on laboratory time scales at conditions fitting either the Atacama Desert on Earth, or the surface of Mars (Wehmann et al. 2023). In light of most recent developments (e.g. Stawski et al. 2016), that advocate for a complex, non-classical nucleation mechanism for all calcium sulphates, we present an analysis of natural samples from the Atacama Desert to identify key features that promote the nucleation and growth of anhydrite under planetary surface conditions. Our analyses reveal at least three distinct anhydrite facies, with differing mineralogy and micro- to nano-structures. The facies are (1) aeolian deposits with sub-μm grain sizes, (2) (sub-)surface nodules that formed from aeolian deposits and (3) selenites with secondary anhydrite rims. Possible mechanisms of their formation will be discussed. T2 - 10th Granada-Münster Discussion Meeting CY - Münster, Germany DA - 29.11.2023 KW - Calcium sulfates KW - Nucleation KW - Planetary surface KW - Hyper-arid PY - 2023 AN - OPUS4-59111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suárez Ocano, Patricia T1 - Incipient Oxidation and Deformation Mechanisms of the Chemically Complex Alloy AlMo 0.5 NbTa 0.5 TiZr in the high temperature regime N2 - The development of refractory chemically complex alloys (rCCAs) has been explored for potential use in high temperature applications. An example of this is the AlMo0.5NbTa0.5TiZr alloy. It was named as “high entropy superalloy” as it resembles the well-known γ/γ’ microstructure in Ni-Base superalloys with cuboidal particles embedded in a continuous matrix. However, the continuous phase in Ni Base alloys is an fcc solution and the cuboidal γ’ precipitates present the L12 intermetallic structure. On the opposite, this CCA has a reversed microstructure where the continuous matrix is formed by an ordered B2 phase which contains cuboidal precipitates of a disordered BCC phase. Some of the most importat results of microstructural analysis, creep test and oxidation are presented in the following work. The as-cast sample shows a bcc/B2 structure with hexagonal phase precipitates in amorphous state whereas the annealed sample also shows a combination of these phases but with larger bcc precipitates and a fully crystallized hexagonal intermetallic. It was found that porosity was higher in the annealed samples (Kinkerdall effect) and the hardness was higher in samples with faster cooling rate due smaller nanostructure. Norton plots show both diffusion and dislocation controlled deformation, and it was found different kinetics between dry and humid air oxidation with the presence of spallation. T2 - CONVEMI 2021 (Venezuelan congress of microscopy and microanalysis) CY - Online meeting DA - 29.10.2021 KW - High entropy superalloys KW - Mechanical properties KW - Oxidation behavior KW - Microstructural analysis PY - 2021 AN - OPUS4-54382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Heat-driven synthesis of gold nanoparticles from gold microparticles in an e-beam of an SEM N2 - The synthesis of gold nanoparticles from a microparticle precursor were done by illuminating the precursor with an e-beam in an SEM. To understand the driving physical mechanism, a model for thermodynamic calculation were set up and solved numerically. The results support not charging, but heat as the main mechanism. T2 - IFW annual PhD seminar CY - Görlitz, Germany DA - 22.10.2024 KW - Heat-driven synthesis KW - Scanning Electron Microscopy KW - Nanoparticle synthesis PY - 2024 AN - OPUS4-61834 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weinel, Kristina A1 - Schultz, Johannes A1 - Kalady, Mohammed Fayis A1 - Wolf, Daniel A1 - Agudo Jácome, Leonardo A1 - Lubk, Axel T1 - Fabrication of 2-dimensional disordered assemblies of gold nanoparticles and investigation of localized surface plasmon resonances N2 - Interaction of electromagnetic waves, such as electron beams or light, with conductive material can lead to localized surface plasmon resonances (LSPRs) where the incoming energy can be deposited in a collective excitation of electrons of the conduction band, which in turn can result in coherent localized plasmon oscillations. LSPR in metallic nanostructures, such as nanoparticles (NPs), which are sensitive to geometry, material composition and environment, are currently utilized in a wide range of applications, such as surface-enhanced Raman spectroscopy, plasmonic wave guides, improved solar cells, on-chip particle accelerators and nanoantennas. A host of studies that focus on plasmonic NPs ranging from single NPs with several shapes (cubic, spherical, tetrahedral) over 1D assemblies of NPs such as chains, to ordered 2D assemblies of NPs show an increase of the complexity regarding the hybridization behavior of LSPRs eventually lead to delocalized Surface Plasmons. Furthermore, Anderson predicted in 1977 the absence of diffusion or delocalization of waves in disordered systems, which has been discussed as the underlying mechanism for LSPRs localization in disordered metallic thin films and ultrathin 2D networks. Our aim is to further develop these studies on the surface plasmon localization in disordered structures by (1) developing a novel NPs assembly fabrication method that allows fabricating disordered assemblies of NPs of a wide range of NPs sizes, and (2) probing the LSPR with high-resolution electron energy-loss spectroscopy (EELS). Moreover, the dominant dipolar interaction between the NPs, also facilitates an efficient numerical modeling of these systems, which in comparison with the experiments allows for an in-depth study of the impact of various geometric parameters as well as retardation and life-time damping on the observed localization behavior. To synthesize 2D disordered assemblies of gold NPs on a TEM transparent silicon oxide substrate, a new synthesis routine was developed. This procedure is based on sublimation and redeposition of a gold microparticle precursor induced by an electron beam in a scanning electron microscope (SEM) operated at 30 kV. To characterize the assembly of synthesized NPs in terms of size, shape and spreading over the substrate, TEM measurements were conducted subsequently. To study LSPRs experimentally, EELS in scanning transmission electron microscopy (STEM) mode was carried out. The numerical modelling of LSPRs was performed using a self-consistent dipole model. The synthesized 2D disordered gold NPs assemblies exhibit a gradient in the NPs mean size, which ranges from 100 nm close to the precursor location down to 2 nm at a distance of more than 20 µm from the precursor location. Additionally, the interparticle distance between the gold NPs increases with increasing distance to the precursor location. The experimental investigation as well as the numerical simulation of the LSPRs demonstrate a localization behavior that decreases toward larger energies, which is driven by the disorder of the NPs assembly (mainly the random particle distance). That localization behavior stays in contrast to what was found in ultrathin 2D gold networks showing increasing of localization towards higher LSPRs energies. By varying the geometric parameters of the NPs assembly in the simulation, we could identify the NPs thickness as the parameter, that determines the energy-dependence of the localization. Specifically, a critical thickness of approx. 10 nm separates the two localization regimes, which correlates to the energy of the dipole mode resonance crucially depending on the thickness of the NPs. 2D disordered assemblies of gold NPs of a wide range of NPs sizes and distances can be synthesized directly on thin substrates facilitating structural characterization and EELS measurements in a TEM. It could be shown that such assemblies exhibit LSPRs with a localization behavior that may be tuned by the NPs sizes (including thickness) and interparticle distances. The proposed synthesis of random NPs assemblies opens new avenues for fundamental studies on Anderson localization in disordered plasmonic structures as well as its applications such as surface-enhanced Raman spectroscopy where localization behavior must be tuned to specific wave lengths. T2 - 17th European Microscopy Congress (EMC 2024) CY - Copenhagen, Denmark DA - 26.08.2024 KW - Scanning electron microscopy KW - Gold nanoparticle synthesis KW - Disordered assemblies KW - Localized surface plasmon resonances KW - Transmission electron microscopy PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618330 DO - https://doi.org/10.1051/bioconf/202412932007 VL - 129 SP - 1 EP - 2 PB - EDP Sciences CY - Les Ulis AN - OPUS4-61833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suárez Ocaño, Patricia A1 - Agudo Jácome, Leonardo T1 - Creep degradation of the high entropy superalloy AlMo0.5NbTa0.5TiZr N2 - The refractory high entropy superalloy (RSA) AlMo0.5NbTa0.5TiZr was the first of a class, with a dual-phase microstructure that resembles that of γ/γ’ in Ni-base superalloys), and the open question whether it performs better as structural alloy under high temperature (HT) applications. Here, we address the HT creep behavior and its associated microstructural degradation of this RSA. The material was produced by arc-melting, heat treatment in argon (24 h @ 1400 °C + 4 h hot isostatic pressure @ 1370 °C & 170 MPa). Interrupted vacuum creep tests were performed at 900-1100 °C and 30-120 MPa. Scanning (S) and transmission (T) electron microscopy (EM) were used to reveal degradation mechanisms. At 1100 °C (Fig.1, middle), the dual A2/B2 microstructure coarsens and partially transforms into a Zr-Al-rich phase (red arrow). An additional external load pronounces directional coarsening. Results are further discussed on the base dislocation and additional damage mechanisms. T2 - International Conferende on Strength of Materials (ICSMA) 2022 CY - Metz, France DA - 26.06.2022 KW - High entropy superalloy KW - Rrafting KW - Dislocation creep KW - Phase transformation PY - 2022 AN - OPUS4-63856 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 - JOUR A1 - Agudo Jácome, Leonardo A1 - Manzoni, Anna Maria T1 - Elementverteilung in Hochentropiewürfelchen N2 - Seit Beginn der Luftfahrt Anfang des letzten Jahrhunderts ist die Menschheit auf der Suche nach neuen Materialien, die das Abenteuer Fliegen sicherer, angenehmer, schneller und rentabler gestalten. Hochentropielegierungen sind solche vielversprechenden Materialien. Die richtige Analytik hilft dabei, besser zu verstehen, wie deren Zusammensetzung und atomare Anordnung die makroskopischen Eigenschaften beeinflusst. KW - Chemically complex alloy KW - Transmissionselektronenmikroskopie KW - Energiedisersive Röntgenspektroskopie PY - 2022 UR - https://www.gdch.de/fileadmin/downloads/Netzwerk_und_Strukturen/Fachgruppen/Analytische_Chemie/Mitteilungsblatt/Internet_AC04-2022.pdf SN - 0939-0065 IS - 4 SP - 12 EP - 14 PB - Gesellschaft Deutscher Chemiker CY - Frankfurt, Main AN - OPUS4-56699 LA - deu 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 - CONF A1 - Agudo Jácome, Leonardo T1 - Navigating the Nanoworld: Understanding Materials Properties with the Transmission Electron Microscope N2 - The field of materials science is defined as “the study of the properties of solid materials and how those properties are determined by a material’s composition and structure.”. Many –if not most– of the materials that are produced nowadays owe their properties to structures engineered down to the nanoscopic level. This need has been partly realized thanks to the understanding of materials’ building blocks via characterization techniques that reach this level of resolution. Transmission electron microscopy, since its first implementation in the early 1930s (in Berlin), has been implemented to achieve imaging –and spectral– analysis at lateral resolutions down to the atomic level. In this contribution, a series of practical examples will be presented, where applied materials are characterized by a range of transmission electron microscopy techniques to understand structural and functional properties of a wide range of materials. Among these materials examples will be presented on structural conventionally and additively manufactured metallic alloys, high entropy alloys, dissimilar aluminum-to-steel welds, magnetic nanoparticles, ceramic coatings, high temperature oxidation products. Addressed will be either the effect of processing route or that of the exposure to experimental conditions similar to those found in the respective intended applications. T2 - UA/UAB/UAH MSE Graduate Seminar CY - Online meeting DA - 19.01.2022 KW - Transmission electron microscopy (TEM) KW - Characterization KW - Microstructure KW - 3D PY - 2022 AN - OPUS4-54238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gadelmeier, C. T1 - Strengthening mechanisms of single crystalline CrCoNi and CrMnFeCoNi at creep temperatures above 700 °C N2 - The main deference between high entropy alloys and conventional alloys is the solid solution strengthening effect, which moves from a single element to a multi-element matrix. Little is known about the effectiveness of this effect at high temperatures. Investigation of temperature dependent solid solution strengthening in single phase multicomponent alloys with medium and high entropy using creep testing was performed. Creep tests carried out on single phase SX CrCoNi , CrMnFeCoNi and pure Ni from 700 to 1200 °C excluding oxidation, grain boundaries and multiphase effects. It was found that the influence of solid solution strengthening of CrCoNi and CrMnFeCoNi increases by decreasing temperature (1200 to 700 °C), and dislocation forests occur in CrCoNi and CrMnFeCoNi in comparison to pure Ni. T2 - SPP Kick-Off Meeting 2nd Phase CY - Online meeting DA - 14.04.2021 KW - High entropy alloys KW - Mechanical properties KW - Transmission electron microscopy KW - Solid solution strengthening PY - 2021 AN - OPUS4-54381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Croteau, Jean-Francois T1 - Electro-hydraulic forming of SRF cavities: Effect of strain rate on niobium single crystals N2 - An investigation of the dislocation substructure and mechanical properties of high-purity niobium single crystals with different initial crystal orientations deformed in tension at strain rates of 10^{-4} to 10^3 s^{-1} is presented. Specimens were cut from a large grain niobium disk used for the manufacturing of SRF cavities. Different crystallographic tensile directions exhibited significantly different softening and hardening behaviors and elongation at fracture. Such anisotropy is reduced at high strain rates. Also, different dislocation substructures were observed with TEM at low and high strain rates. At low strain rates, dislocation cells with a high density of long dislocations were observed. At high strain rates, homogeneously distributed dislocations with a higher dislocation dipole density were observed. The relationship between the differences in dislocation substructures and mechanical properties at low and high strain rates and the potential effects on the superconducting properties are discussed. T2 - 2021 International Conference on RF Superconductivity (SRF'21) CY - Online meeting DA - 28.06.2021 KW - Dislocation substructure KW - Strain rate dependence KW - Transmission electron microscopy (TEM) PY - 2021 UR - https://indico.frib.msu.edu/event/38/attachments/158/1089/TUPCAV012_poster.pdf AN - OPUS4-54540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria T1 - Über das Zusammenspiel von Gitterfehlpassung, Kriecheigenschaften und γ'-Würfelform in Hf-W-modifizierten Al10Co25Cr8Fe15Ni36Ti6—Legierungen N2 - Spurenelemente spielen eine wichtige Rolle bei der Verfeinerung der Eigenschaften von komplexen Materialien. Diese Arbeit zeigt die Korrelation zwischen der Mikrostruktur, der Gitterfehlpassung und den Kriecheigenschaften. Die Legierung Al10Co25Cr8Fe15Ni36Ti6 (in at. %) mit komplexer Zusammensetzung wurde mit den Elementen Hf und W verstärkt. Die Zugabe von Hf bewirkt eine eckigere Form der würfelförmigen gamma'-Ausscheidungen und einen erhöhten Anteil der Heusler-Phase. Die Zugabe von W wiederum formt die Würfelchen rundlicher und löst die Heusler-Phase auf. Eine Mischung der beiden Spurenelemente zeigt einen Übergang zwischen den beiden Extremen, sowohl in Hinsicht auf die Form der Ausscheidungen als auch in Bezug auf die Gitterfehlpassung und die Kriecheigenschaften. T2 - 11. Metals and Alloys Seminar CY - Cala Santanyi, Spain DA - 20.06.2022 KW - Hochentropie-Legierung KW - Kriechversuche KW - Gitterfehlpassung KW - Transmissionselektronenmikroskopie PY - 2022 AN - OPUS4-55396 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria T1 - Early Material Damage in Equimolar CrMnFeCoNi in Mixed Oxidizing/Sulfiding Hot Gas Atmosphere N2 - The use of more and more varied fuels implies an increased list of criteria that need to be addressed when choosing a material for a combustion chamber and its supply pipes. The materials must be very resistant against corrosion, especially when the process takes place at temperatures above 500°C. In this work the influence of SO2 on the surface of the “Cantor alloy” is investigated. T2 - HEA-Symposium "Potential for industrial applications" CY - Dresden, Germany DA - 12.05.2022 KW - High entropy alloy KW - Corrosion KW - Sulfiding KW - Transmission electron microscopy PY - 2022 AN - OPUS4-55397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria T1 - Mechanical performance and integrity of tungsten inert gas (TIG) welded CoCrFeMnNi high entropy alloy with austenitic steel AISI 304 N2 - High entropy alloys (HEA) are a new class of materials that have been investigated since the early 2000s and offer great potential to replace conventional alloys. However, since they sometimes have significant contents of expensive alloying elements such as Co or Ni, their use is only conceivable in highly stressed areas of components. For this purpose, the weldability with conventional alloys such as high-alloy austenitic steels must be investigated. In addition to the resulting microstructure, the mechanical properties are also fundamental for the usability of HEAs in DMWs. For this purpose, TIG welds of CoCrFeMnNi HEA (cold rolled and recrystallized state) with AISI 304 austenitic steel are investigated. These mechanical properties are analyzed in this work by means of tensile tests and local hardness measurement. The local strain behavior of the welded joints is also characterized by means of Digital Image Correlation (DIC). The results of the local hardness measurement show a clear influence of the initial condition of the HEA on the HAZ. Thus, the HEA in the cold-rolled condition shows a clear softening because of recrystallization processes in the HAZ. On the other hand, there is no influence on the hardness of the weld metal, which is approx. 200 HV0.1 in both cases. The tensile tests show a consistent failure of the weld in the weld metal. However, regardless of the HEA condition, strengths in the range of the recrystallized HEA (RM ~ 550–600 MPa) are achieved, although with significantly reduced fracture elongations. T2 - International Conference on High-Entropy Materials (ICHEM 2023) CY - Knoxville, TN, USA DA - 18.06.2023 KW - Multi-principal element alloys KW - Welding KW - Mechanical properties KW - Dissimilar metal weld KW - Digital image correlation PY - 2023 AN - OPUS4-57713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Damage induced by electric field of gold microparticles on silicon oxide substrate in the scanning electron microscope N2 - 1. Introduction A normally unwanted process that can arise when converging an electron beam onto, e.g. microparticles, has been called "damage induced by electric field" (DIEF) [1]. By DIEF, the convergent electron beam (CEB) imparts a high amount of energy to the microparticle locally and strongly interacts with its atoms. At a specific current density J, which can be controlled by the convergence angle α, the irradiated material begins to transform. The phenomenon of expelling nanomaterial from microparticles under the influence of a convergent electron beam (CB) in a transmission electron microscope (TEM) has been largely studied [2]. Several types of nanoparticles (NPs) have been observed for different metallic materials and metal oxides after specific CB protocols (P) in the TEM. Thus, DIEF can be used as a promising synthesis method controlled changes of micrometric material to create new nanometric material compositions and morphologies. While these reactions have been observed in situ at the high acceleration voltages associated with TEM, it remains unclear whether the SEM can also be used to fabricate NPs via DIEF. In contrast to TEM there is no possibility to statically convert the electron beam to a range of α to reach the needed J as in TEM. Instead, the scanning parameters and the magnification can be manipulated so as to find an integrated J. Considering that the scanning electron microscope (SEM) is easier to use, more accessible and cheaper than a TEM, here we explore the possibility to transfer the concepts of DIEF known to operate in the TEM for in situ NP generation SEM. 2. Objectives The main goal is to determine whether DIEF can be translated to the SEM perform to controlled in situ fabrication of nanoparticles from microparticles, using gold microparticles on amorphous SiO substrate as precursors. We determine what experimental parameters must be taken into account to create SEM-based CBPs for NP creation in the SEM with these materials. 3. Materials & methods Gold microparticles with diameter of around 1 to 3 µm were deposited on electron transparent amorphous SiO/SiO2 substrate. Using a convergent electron beam protocol (CBP) in a scanning electron microscope (SEM) at an acceleration voltage of 30 kV, the gold microparticles were irradiated until a production of NPs takes place as shown in figure 1. The beam current varied between 16 and 23 nA. 4. Results Depending on the CBP parameters, either only Au NPs or a mixture of Au and Si NPs are produced. The particle size ranges from a few nm up to 100 nm, and it depends on the distance of the NP to the initial position of the microparticle. Further beam parameters such as the dwell time, the effective irradiated volume and particle size determine whether NPs are produced or if the microparticles only are expelled from the substrate without reacting. 5. Conclusion The SEM can be used as an instrument for synthesizing nanomaterials via DIEF. Different CBP protocols can be applied for obtaining either gold nanoparticles or silicon + gold nanoparticles T2 - Microscopy Conference CY - Darmstadt, Germany DA - 26.02.2023 KW - Scanning electron microscopy (SEM) KW - Gold nanoparticles KW - Electron beam induced modification PY - 2023 AN - OPUS4-58261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Complex artificial features on a TEM transparent membrane N2 - The phenomenon of expelling nanomaterial from microparticles of different materials, such as Au, WO3 or B2O3 under the influence of a convergent electron beam (CB) of a transmission electron microscope (TEM) was reviewed by Ignacio Gonzalez-Martinez [1]. Converging the e-beam in a TEM means that a high amount of energy enters the microparticle at a very local place and interact with the matter. Obviously, during the convergent beam protocol, no imaging with the electron beam is possible, but at the end, nanoparticles with different appearances lie down next to the microparticle while its size is reduced. Hence, there is a blind spot in the observation, which we want to fill, as we want to help clarify the nature of the expelling phenomenon. One hypothesis that explains the phenomenon is the so-called damage (of the microparticle) induced by an electric field (DIEF). Within this theory, the material is ionized and expelled in form of ionic waves. Our aim is therefore to fabricate specimens with artificial microlandscapes, as schematically exemplified in figure 1a), using the focused ion beam (FIB) and micromanipulators, as experimental setups to follow the paths of the expelled material. As a first step towards the fabrication of such specimen, we make experimental feasibility studies for each fabrication method, FIB structuring with Ga+ ion beam and micromanipulated microparticle deposition. Bridges (gray regions in Fig. 1) are created by milling a commercially available electron transparent membrane (silicon oxide or carbon) of a Cu-TEM grid. Platinum or carbon walls (blue features in Fig. 1) are built to stand on those bridges. Microparticles (yellow sphere in Fig. 1) of gold or other material are deposited in the center of the bridges. Figure 2a) shows four square holes (black area) and between them the residual silicon oxide membrane bridges (dark grey). On top of the bridges, walls (light grey) are deposited. The width of the bridges is different, the walls overlap the holes as well as the distance between the walls is very small, so these and other parameters need to be optimized. Figure 2b) shows a square hole (black) with bridges (white) on the right side on top of a carbon membrane (grey). There are still some obstacles which needs to be eliminated. For instance, the deposition process of the walls is not reliable as visible at the wall on top where a hole arises instead of a wall. These studies are still in progress and the results are further discussed in terms of the applicability for the DIEF experiment in the TEM. T2 - 4th EuFN and FIT4NANO Joint Workshop / Meeting CY - Vienna, Austria DA - 27.09.2021 KW - Transmission electron microscope (TEM) KW - Sample preparation KW - Micromanipulation KW - Focussed ion beam growth KW - Nano-landscape PY - 2021 AN - OPUS4-58259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael T1 - Welding of high-entropy alloys - New material concept vs. old challenges N2 - HEAs represent a relatively new class of materials. The the alloy concept is fundamentally different from the most conventional materials and alloys that are used today. Recently, the focus of HEA designs is more application-based. For that purpose, the elements of interest are carefully selected and multiple phases as well as micro-structures are deliberately adjusted. Currently, only limited attention has been paid to weldability of HEA. This encompasses possible effects on metallurgy and its influence on the desired properties. It remains open if welding causes e.g. considerable number of intermetallic phases or segregations and their effect on weld joint properties. For that reason, the scope of this study is to summarize already available studies on welding of HEAs with respect to the HEA-type, the applied welding process and its influence on the weld joint properties. T2 - IIW Annual Assembly, Meeting of Commission II-A CY - Online meeting DA - 20.07.2020 KW - High-entropy alloy KW - Welding KW - Review PY - 2020 AN - OPUS4-51116 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Manzoni, Anna Maria A1 - Glatzel, U. ED - Buschow, K.H.J. ED - Flemings, M.C. ED - Kramer, E.J. ED - Veyssière, P. ED - Cahn, R.W. ED - Ilschner, B. ED - Mahajan, S. T1 - High-Entropy Alloys: Balancing Strength and Ductility at Room Temperature N2 - A new race for high performance structural materials has started since the discovery of high entropy alloys at the beginning of the 21st century. The possible combination of several elements in an, until then, unknown composition space opened the ground for discovering new materials. Solid solution strengthening remains the most prominent mechanisms that is active in this family of materials, but it is supported by all other strengthening mechanism on the path to better and better performing materials. Chemical, thermal and mechanical approaches are combined to optimize these alloys. Optimum performances can be reached by using a high number of different strengthening mechanisms, induced both by composition and processing. The most prominent with composition induced mechanism is precipitation hardening, and on the processing side it is cold working such as cold-rolling, torsion or extrusion. The contribution uses tensile test data at room temperature solely for comparison – high temperature and cryogenic data are omitted because it would lead beyond the scope of this manuscript. KW - High entropy alloys KW - Compositionally complex alloys PY - 2020 DO - https://doi.org/10.1016/B978-0-12-803581-8.11774-6 PB - Elsevier Inc. AN - OPUS4-50575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suárez Ocano, Patricia T1 - Microstructural characterization of the AlMo 0.5 NbTa 0.5 ZrTi refractory complex concentrated alloy N2 - A set of some unexpected and interesting microstructures has put the so-called complex concentrated alloys (CCAs) in the eye of the scientific community and the AlMo0.5NbTa0.5TiZr refractory (r)CCA, aimed at substituting Ni-base superalloys in gas turbine applications, belongs to this alloy family. The AlMo0.5NbTa0.5TiZr rCCA was studied by SEM, EDX, EBSD and TEM, showing the presence of a nanoscopic basket-wave structure inside the grains, with two BCC phases. Additionally, thermodynamic calculations on the AlMo0.5NbTa0.5TiZr alloy were done with two different proprietary databases that anticipate two BCC-disordered phases with distinct constitutions as well as an HCP phase. T2 - Symposium on Advanced Mechanical and Microstructural Characterization of High-Entropy Alloys CY - Bochum, Germany DA - 03.02.2020 KW - High Entropy Alloy KW - EBSD KW - Microstructure Characterization PY - 2020 AN - OPUS4-50729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sonnenburg, Elke T1 - Präparation, Kontrastierung und Darstellung des Gefüges von additiv gefertigtem austenitischem Stahl 316L N2 - Der weit verbreitete austenitische Stahl 316L soll auch mittels additiver Fertigung verarbeitet werden (316L-AM). Zur Entwicklung optimaler Aufbauverfahren ist ein detailliertes Verständnis des Gefüges notwendig. Das additiv aufgebaute Gefüge zeigt eine Mikrostruktur, die geprägt ist von sehr hohen Abkühlraten und gerichtetem Kornwachstum. Mittels klassischer Metallographie können die Charakteristika des Gefüges wie Körner, Subkörner und Schmelzlinien sichtbar gemacht werden. Mittels EBSD werden Kristallorientierungen ermittelt und bildhaft aufbereitet. Die Feinstruktur der Körner wird im REM in der Übersicht aufgelöst. Erst im TEM kann bei hoher Vergrößerung die Natur der Zellstruktur quantitativ ermittelt werden. T2 - Metallographie 2020 CY - Online meeting DA - 16.09.2020 KW - Präparation KW - Kontrastierung KW - Additiv gefertigter Stahl PY - 2020 AN - OPUS4-51244 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria T1 - High temperature oxidation of the CrFeNi medium entropy alloy N2 - The oxidation behaviour of any alloy is a key issue which determines whether this material is suited for application. In this study, a single-phase equiatomic CrFeNi alloy was exposed to synthetic air at 1000 - 1100 °C for 24 - 1000 h and compared to 316L steel. The oxidation rate of CrFeNi was parabolic at the lower temperatures 1000 °C and 1050 °C, but at 1100 °C a first breakaway occurred after 4 h of exposure. In all cases, the oxide scales were found to partially spall off. As expected, Cr diffuses outwards to form a Cr2O3 layer at the gas/oxide interface. A thin layer of (Cr, Fe, Ni)3O4 is identified at the oxide/alloy interface. The CrFeNi alloy does not show any catastrophic oxidation behaviour at the investigated conditions unlike the 316L alloy, which contains more Mn and Fe. T2 - MSE 2024 CY - Darmstadt, Germany DA - 24.08.2024 KW - Corrosion KW - Medium entropy alloy KW - Scanning electron microscopy PY - 2024 AN - OPUS4-62434 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Damage induced by electric field of microparticles in the electron microscope N2 - Damage induced by electric field (DIEF) that happens in the transmission electron microscope (TEM) when converging the electron beam (e-beam) on microparticles (MPs) can be used to synthesis new nanomaterial and nanomaterial compositions. The research questions are to clarify the limits and possibilities of the method regarding materials that can be produced, systems to which it is applicable and working beam parameters. Synthesis of nano-objects from microparticles using DIEF in TEM could be shown for different materials. Additionally, DIEF using the e-beam in a scanning electron microscope (SEM) can also be used to synthesis nano-objects. A deeper material analysis of this nano-objects was done using TEM and shows that the material of the nanoparticles (NPs) can be gold or/and silicon. Furthermore, the size of the NPs depends on the distance to the center of DIEF whereby the larger NPs are closer to the center. The areas of gold NPs are promising candidates for plasmonic or photonic devices for energy storage or transport. T2 - PhD-Day 2022 CY - Berlin, Germany DA - 06.09.2022 KW - Electron microscopy KW - Electron beam induced modification KW - Gold nanoparticles PY - 2022 AN - OPUS4-58264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -