TY - CONF A1 - Charmi, Amir T1 - Mechanical anisotropy of LPBF 316L: a modeling approach N2 - The underlying cause of mechanical anisotropy in additively manufactured (AM) parts is not yet fully understood and has been attributed to several different factors like microstructural defects, residual stresses, melt pool boundaries, crystallographic and morphological textures. To better understand the main contributing factor to the mechanical anisotropy of AM stainless steel 316L, bulk specimens were fabricated via laser powder bed fusion (LPBF). Tensile specimens were machined from these AM bulk materials for three different inclinations relative to the build plate. Dynamic Young's modulus measurements and tensile tests were used to determine the mechanical anisotropy. Some tensile specimens were also subjected to residual stress measurement via neutron diffraction, porosity determination with X-ray micro-computed tomography, and texture analysis with electron backscatter diffraction (EBSD). A crystal plasticity model was used to analyze the elastic anisotropy and the anisotropic yield behavior of the AM specimens, and it was able to capture and predict the experimental behavior accurately. Overall, it was shown that the mechanical anisotropy of the tested specimens was mainly influenced by the crystallographic texture. T2 - 2. Online-Workshop "In-situ Monitoring and Microstructure Development in Additive Manufactured Alloys " CY - Online meeting DA - 20.04.2021 KW - Anisotropy KW - Crystal plasticity KW - Additive manufacturing PY - 2021 AN - OPUS4-52603 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella A1 - Trappe, Volker T1 - Non-destructive characterization methods for polymer matrix composites N2 - The mechanical behavior of fiber reinforced composites with polymer matrix is governed by several mechanisms operating at different length scales. In this contribution we describe first non-destructive techniques which are adequate for the characterization of the fiber-matrix interphase at a microscopic level. In a second step we describe on a mesoscopic level the influence of manufacturing related elements on the mechanical properties of rotor blades for wind turbines. We concentrate on thermography, laminography and ultrasound in connection with mechanical testing systems. Finally we present methods for monitoring rotor blades by using embedded optical fibers. T2 - Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ, Brasilien CY - Online meeting DA - 26.11.2020 KW - Polymer matrix composites PY - 2020 AN - OPUS4-52043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Portella, Pedro Dolabella A1 - Krebber, Katerina T1 - Fiber Optic Sensors for SHM - From Laboratory to Industrial N2 - The paper highlights the research activities in Germany and Europe in the development of distributed fiber optic sensor for structural health monitoring (SHM) like the monitoring of geotechnical and civil infrastructures and presents selected results achieved within these projects. T2 - Conaendi & IEV 2021 CY - Online meeting DA - 09.03.2021 KW - Fiber KW - Optic KW - SHM PY - 2021 AN - OPUS4-52254 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Thermo-mechanical fatigue of glass fiber reinforced polymer N2 - Glass fiber reinforced polymer (GFRP) materials in practical applications have to endure cyclic mechanical loading in a wide temperature range (e.g. aircraft applications, automotive, wind turbine blades). In this study the static strength and fatigue behavior of GFRP was investigated in a temperature range from 213 K to 343 K. Therefor the coefficients of thermal expansion of the composite as well as the matrix are measured in this temperature interval. The inverse laminate theory was extended and used to calculate the inter fiber-failure effort for a virtual UD-layer according to the layer wise strength approach. The experimentally determined results are compared with the micro-mechanical model according to Krimmer, which has been enhanced to include the effect of temperature and fiber-perpendicular failure modes. A correlation between matrix effort, the dilatational strain energy of the matrix and the damage state of the specimen is demonstrated. It is shown that a fatigue life assessment can be performed with the aid of a temperature-independent master fatigue curve, as it was similar done for the fatigue behavior of CFRP and GFRP to very high load cycles at room temperature. T2 - ICFC8 - The 8th International Conference on the Fatigue of Composites CY - Online meeting DA - 23.06.2021 KW - Glass fibre reinforced plastics KW - Fatigue KW - Thermo-mechanical-loading PY - 2021 AN - OPUS4-52910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Tensile Test Ontology used in Platform Material Digital (PMD) N2 - Data analysis methods play an important role in both the experimental and simulation-based digital description of materials but have so far been poorly structured. The platform Material Digital (PMD) is supposed to contribute to a standardized description of data processing methods in materials research. The goal is the quality assurance of the processes and the output data, the acquisition and definition of their accuracy as well as the interoperability between applications. Therefore, application ontologies are created to explicitly describe processes and test methods. In this presentation, the first efforts within the joint project PMD in creating a tensile test application ontology in accordance with the ISO standard 6892-1:2019-11 are shown. Especially, the path of ontology development to be pursued based on standards was focused. Furthermore, the presentation includes a live demonstration of queries possibly performed to query data that was uploaded in the PMD triple store. T2 - Online Workshop: An introduction to the semantic web and ontologies CY - Online meeting DA - 23.04.2021 KW - Ontology KW - Tensile Test KW - Platform Material Digital KW - PMD KW - Knowledge Graphs KW - Semantic Web PY - 2021 AN - OPUS4-52949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bettge, Dirk T1 - MGA Round Robin Test on Al-AM Fatigue Testing - Fractographic Results N2 - Presentation of results of an investigation of fracture mechanisms and crack start sites of an additive manufactured aluminium alloy after fatigue testing. Collaboration within the MGA initiative (Mobility Goes Additive). T2 - MGA Mid Term Meeting 2022 CY - Berlin, Germany DA - 05.07.2022 KW - Aluminium Alloy KW - Fractography KW - Additive Manufacturing PY - 2022 AN - OPUS4-55192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Dynamic mechanical analysis of epoxy-matrix cross linking measured in-situ using an elastomer container N2 - A new patented dynamic mechanical analysis (DMA) is presented, where the tensile, bending- or torsional stiffness of a media can be characterized in-situ during the phase transition from liquid to solid. An epoxy system, e.g. Hexion L285/H287, is filled into an elastomer container, such as a silicone tube. This can be mounted into a conventional DMA and, based on a linear viscoelastic approach, the storage modulus (E’;G’), the loss modulus (E’’;G’’) and the loss angle tan(delta) can be measured at constant temperature as a function of time in order to investigate the liquid to sol-gel to solid transition. With this new method, the stiffness increase as a result of the cure process can be directly measured more precisely than with a rheometer in a shear plate set-up, because using an elastomer container gives a defined cross section for calculating the Young’s modulus. T2 - 20th European Conference on Composite Materials, ECCM20 CY - Lausanne, Switzerland DA - 26.06.2022 KW - Dynamic mechanical analysis (DMA) KW - Thermoset polymers KW - Cure process KW - Cross linking PY - 2022 AN - OPUS4-55213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Suárez Ocano, Patricia T1 - I n situ monitoring of growing oxidation of the chemically complex alloy AlMo 0.5 NbTa 0.5 TiZr in the high temperature regime using synchrotron radiation Preliminary results N2 - The chemically complex alloys (CCAs) 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 many technological applications, e.g. aeroengine turbines. However, the field of CCAs, especially their resistance in harsh (oxidative) and hot environment is still young and not much experimental evidence for the understanding mechanisms in this regime is available, which the proposed study addresses. For safe use in structural applications, in addition to their mechanical performance, the environmental resistance of this alloy is also critical. Surface degradation can significantly decrease the mechanical resistance during high temperature exposure, leading to premature failure. The AlMo0.5NbTa0.5TiZr rCCA only contains Al as a protection candidate and it is composed of a coherent B2/bcc nanoscopic cube-on-cube interweave and an hexagonal phase. The evaluation of the oxidation process in the AlMo0.5NbTa0.5TiZr rCCA in the heat-treated state has not been assessed yet. The proposed study focusses on a deeper understanding of the formation mechanism and growth kinetics of oxides at high temperature in the AlMo0.5NbTa0.5TiZr rCCA using synchrotron radiation. Due to the envisaged high temperature structural applications, the alloy is evaluated in an oxidation environment specifically between 800°C and 1000°C. T2 - Large scale facility-based techniques SPP meeting CY - Online meeting DA - 02.11.2021 KW - Refractory chemically complex alloys KW - Oxidation behavior KW - Microstructural analysis KW - Synchrotron radiation PY - 2021 AN - OPUS4-54383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghafafian, Carineh T1 - Fully-reversed fatigue behavior of scarf joint repairs for wind turbine blade shell applications N2 - Due to manufacturing imperfections which can propagate to damage under in-service loads, wind turbine rotor blades, made primarily of glass fiber reinforced polymers (GFRP), often fail significantly before their design life. To enable a quick and cost-effective return to service, localized repairs can be executed by technicians in the field, directly accessing the blades by suspended roping. Scarf joint repairs, shown to be highly efficient with a smooth load transition across angled joint walls and a restored aerodynamic profile, are the focus of this study. The damage mechanisms of these structures were examined under fully-reversed mechanical cyclic loading with a load ratio R = -1, which was made possible on the coupon scale by a custom designed anti-buckling support. The number of cycles to failure were compared across load levels. While the scarf joint ratio was held constant at 1:50, known from industry and literature to be a good compromise between restored mechanical properties and repair size, the layup sequence was varied between small-to-large and large-to-small. Hereby the effect of the presence of resin pockets and fiber orientation mismatch between the parent and repair structure on the failure mechanism as well as fatigue strength of ±45° GFRP scarf joint repair structures was studied. Strain development across the joint length was measured to assess stiffness degradation in addition to the fatigue strength recovery of scarf joint structures with respect to pristine reference specimens. Grayscale analysis was used to monitor the damage state leading to fracture across the specimens. Post-mortem fractography analysis with light microscopy described the global failure mechanisms as well as local damage distribution within the structure, all of which provided insight to critical variables in scarf joint GFRP structures under fully-reversed mechanical cyclic loading, allowing for the tailoring of such repairs on wind turbine blade shells for maximum restoration of service life. T2 - 20th European Conference on Composite Materials (ECCM20) CY - Lausanne, Switzerland DA - 26.06.2022 KW - Glass fiber reinforced polymers KW - Scarf repairs KW - Fatigue PY - 2022 AN - OPUS4-55638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Scarf-joint repairs under fatigue loading investigated for sandwich shell applications N2 - Wind turbine rotor blades are produced as aerodynamic, three-dimensionally formed sandwich shell structures using mainly glass fiber reinforced plastics (GFRP). The GFRP used today have the potential to withstand the harsh operating conditions of rotor blades over the projected service life of 20 years. Premature damages that occur can be traced primarily back to design and/or manufacturing imperfections, as well as unusually high load scenarios (for instance lightning strikes, or strong winds combined with system control errors). Therefore, rotor blades have to be repaired several times (on average 2-3 times) during their projected service life. Approximately 70% of these are repairs of small- to medium-sized sandwich shells, carried out by technicians directly accessing the blade by suspended roping at the wind turbine location. The goal is to execute repairs that will last over the remaining service life, i.e. be sustainable. Within the framework of a research project carried out at BAM, Division 5.3 Polymer Matrix Composites, Department 5 for Materials Engineering, not only was the geometric shape (round vs. square in relation to the top view) varied, but also the layup of the scarf repair structure, variables that have not been studied systematically to-date. Sub-component scale sandwich shell specimens with representative repairs were used in this work in addition to coupon-scale specimens that are more commonly seen in literature. These sub-component shell specimens were tested using a unique shell test bench under loading conditions representative of wind turbine blade shell operating conditions with respect to fatigue strength. Using non-destructive testing methods (field strain measurement and thermography), damage development and distribution was monitored and analyzed in-situ. As a result, a concept was developed in which the repaired areas showed at least equivalent if not higher fatigue strength than the reference shells that were not repaired. T2 - ICFC9 - The 9th International Conference on the Fatigue of Composites CY - Vicenza, Italy DA - 21.06.2023 KW - Repair of sandwich shell structures KW - Non-destructive testing KW - Wind turbine blades PY - 2023 AN - OPUS4-57929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Kalinka, Gerhard A1 - Loose, Florian T1 - Carbon fibre composites exemplarily research at BAM N2 - Lightweighting as a cross-cutting technology contributes significantly to achieve the European Green Deal goals. Based on, but not limited to, advanced materials and production technologies, the demand for natural resources and CO2 emmissions are reduced by lightweighting during production, as well as use phase. Therefore, lightweighting is a crucial transformation technology assisting in decoupling economic growth from resource consumption. In this manner, lightweighting contributes significantly as a key technology of relevance for many industrial sectors such as energy, mobility, and infrastructure, towards resource efficiency, climate action and economic strength, as well as a resilient Europe. To strengthen international partnerships, addressing global issues of today at the edge of science with high performance lightweight material based on carbon fibers, an overview about the BAM expertise in carbon fiber reinforced materials is given. T2 - Meeting KCarbon CY - Berlin, Germany DA - 15.06.2023 KW - Lightweighting KW - Carbon Fibers KW - Recycling KW - Push-out Test KW - multi scale testing PY - 2023 AN - OPUS4-58094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - PMD Workshop: Use and benefits of the PMDco N2 - This is an interactive workshop of the Plattform MaterialDigital (PMD) on Semantic Web technologies (SWT) where we delve into the world of ontology development and data structuring in the field of materials science and engineering (MSE). This workshop is designed to equip participants with essential skills in categorizing classes within ontologies, with a special emphasis on the PMD Core Ontology (PMDco). Discover the immense value of ontologies for MSE data reproducibility and reuse and harness the power of PMDco to foster your data management practices. In this workshop, you will explore the intricacies of class categorization when developing ontologies in the MSE domain. Through interactive discussions and hands-on exercises, you will learn effective techniques for structuring and organizing ontologies to enhance data retrieval and analysis. You will gain valuable insights into best practices and considerations for class categorization, aiming at optimal data organization and management within your MSE projects. One of the highlights of this workshop is the introduction to PMDco, a mid-level ontology in the field of MSE developed community-driven in the frame of the project PMD. Learn about PMDco, its underlying concepts, and its application in detail. Discover how PMDco provides a comprehensive framework for MSE data representation, enabling seamless integration and interoperability across different systems and platforms. In addition to exploring PMDco, this workshop will illustrate the benefits of data interoperability and SWT with respect to leveraging the full potential of MSE data. T2 - NFDI MatWerk Conference 2023 CY - Siegburg, Germany DA - 27.06.2023 KW - Workshop KW - Ontology KW - Plattform MaterialDigital KW - PMDco PY - 2023 AN - OPUS4-57802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönauer-Kamin, D. T1 - Powder Aerosol deposited (PAD) calcium cobaltite as textured p type thermoelectric material N2 - Oxide thermoelectric semiconducting materials like p-type calcium cobaltite Ca3Co4O9 are investigated as oxidation- and temperature-resistant thermoelectric materials for thermoelectric generators (TEGs). To realize TEGs in planar film technology, the powder aerosol deposition (PAD) method is emerging recently. PAD is a method to obtain dense ceramic films directly from the synthesized starting powders without a subsequent high temperature step. In the present work, Ca3Co4O9 (CCO) powders are processed by PAD to ceramic films at room temperature. The thermoelectric properties of the films (film thickness 10 – 20 µm) are characterized from room temperature to 900°C. Additionally, the layer morphology and texture of the films will be investigated. As result, the Seebeck coefficient of the CCO-PAD film is comparable to pressed and sintered CCO-bulk materials during the 1st heating cycle to 900°C. The morphology of the films after the thermal treatment shows strong aligned crystallites resulting in a strong texture of the films. The electrical conductivity increases strongly during the 1st heating cycle to 900°C and stays almost constant afterwards. Compared to CCO-bulks, the films provide higher electrical conductivity which could be explained by the oriented crystal growth in-plane direction of the film. The relationship between thermoelectric properties and layer morphology as a function of thermal annealing parameters will be further investigated. T2 - KERAMIK 2023 / 98. DKG-Jahrestagung CY - Jena, Germany DA - 27.03.2023 KW - Layer depostion KW - Texture KW - Heat treatment PY - 2023 AN - OPUS4-57285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Birkholz, H. A1 - Bayerlein, Bernd T1 - PMD Core Ontology: A Community Driven Mid-Level Ontology in the MSE Domain N2 - Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific. In this presentation, an approach how to maintain a comprehensive and intuitive MSE-centric terminology composing a mid-level ontology–the PMD core ontology (PMDco)–via MSE community-based curation procedures is shown. The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications. T2 - FEMS EUROMAT 2023 CY - Frankfurt a. M., Germany DA - 03.09.2023 KW - Knowledge Representation KW - Semantic Interioerability KW - Mid-Level Ontology for MSE KW - FAIR Data Management PY - 2023 AN - OPUS4-58201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lemiasheuski, Anton A1 - Bajer, Evgenia A1 - Oder, Gabriele A1 - Göbel, Artur A1 - Hesse, Rene A1 - Bettge, Dirk T1 - Development of an Automated 3D Metallography System (RASI) and its Application in Microstructure Analysis N2 - Many microstructural features exhibit non-trivial geometries, which can only be derived to a limited extent from two-dimensional images. E.g., graphite arrangements in lamellar gray cast iron have complex geometries, and the same is true for additively manufactured materials and three-dimensional conductive path structures. Some can be visualized using tomographic methods, but some cannot be due to weak contrast and/or lack of resolution when analyzing macroscopic objects. Classic metallography can help but must be expanded to the third dimension. The method of reconstructing three-dimensional structures from serial metallographic sections surely is not new. However, the effort required to manually assemble many individual sections into image stacks is very high and stands in the way of frequent application. For this reason, an automated, robot-supported 3D metallography system is being developed at BAM, which carries out the steps of repeated preparation and image acquisition on polished specimen. Preparation includes grinding, polishing and optionally etching of the polished surface. Image acquisition comprises autofocused light microscopic imaging at several magnification levels. The image stacks obtained are then pre-processed, segmented, and converted into 3D models, which in the result appear like microtomographic models, but with high resolution at large volume. Contrasting by classical chemical etching reveals structures that cannot be resolved using tomographic methods. The integration of further imaging and measuring methods into this system is underway. Some examples will be discussed in the presentation. T2 - Euromat 2023 CY - Frankfurt a. M., Germany DA - 04.07.2023 KW - Metallography KW - 3D Reconstruction KW - Roboter KW - Automation KW - Microstructure PY - 2023 AN - OPUS4-58202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - FAIR Data in Platform MaterialDigital (PMD) - Ontologies , Semantic Data Integration and Data Exchange N2 - Following the new paradigm of materials development, design, and optimization, digitalization is the main goal in materials sciences and engineering (MSE) which imposes a huge challenge. In this respect, the quality assurance of processes and output data as well as the interoperability between applications following FAIR principles are to be ensured. For storage, processing, and querying of data in contextualized form, Semantic Web technologies (SWT) are used since they allow for machine-actionable and human-readable knowledge representations needed for data management, retrieval, and (re)use. The project ‘platform MaterialDigital’ (PMD, https://materialdigital.de) aims to bring together and support interested parties from both industrial and academic sectors in a sustainable manner in solving digitalization tasks and implementing digital solutions. Therefore, the establishment of a virtual material data space and the systematization of the handling of hierarchical, process-dependent material data are focused. Core points to be dealt with are the development of agreements on data structures and interfaces implemented in distinct software tools and to offer users specific support in their projects. Furthermore, the platform contributes to a standardized description of data processing methods in materials research. In this respect, selected MSE methods are semantically represented which are supposed to serve as best practice examples with respect to knowledge representation and the creation of knowledge graphs used for material data. Accordingly, this presentation shows the efforts taken within the PMD project towards the digitalization in MSE such as the development of the mid-level PMD core ontology (PMDco, https://github.com/materialdigital/core-ontology). Furthermore, selected results of a PMD partner project use case addressing data and knowledge management from synthesis, production, and characterization of materials are shown. T2 - 1st VMAP User Meeting 2024 CY - Sankt Augustin, Germany DA - 14.02.2024 KW - Ontology KW - Semantic Web Technologies KW - Plattform MaterialDigital KW - Data Interoperability KW - Data Exchange KW - Data Structures PY - 2024 AN - OPUS4-59567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Electron-beam induced particle synthesis: Phenomenological study of the physical mechanisms N2 - Several studies have shown that the electron beam (e-beam) can be used to create nanomaterials from microparticles in situ in a TEM. However, attempts to produce gold nanoparticles (NPs) on silicon oxide substrate remained to be accomplished. Here, we show that the production of gold NPs is possible by using the e-beam in a SEM, under a set of parameters. To understand the physical mechanisms leading to the gold NPs, the mechanisms of e-beam induced charging as well as e-beam induced heating of the MPs were discussed. Several hints point to heating as the driving mechanism. T2 - IFW Dresden, Seminar CY - Dresden, Germany DA - 06.12.2023 KW - Electron-beam-induced modification KW - Nanoparticle synthesis KW - Scanning electron microscopy KW - Driving physical mechanism KW - Negative charged microparticle KW - Temperature driven process PY - 2023 AN - OPUS4-59081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Electron-beam-induced production of gold nanoparticles N2 - Several studies have shown that the electron beam (e-beam) can be used to create nanomaterials from microparticles in situ in a TEM. However, attempts to produce gold nanoparticles (NPs) on silicon oxide substrate remained to be accomplished. Here, we show that the production of gold NPs is possible by using the e-beam in a SEM, under a set of parameters. The NPs produced present a size gradient along the radial direction. A parameter study shows that the microparticles may: 1) flicker away without producing NPs, 2) fragment to form NPs and/or 3) react with the silicon oxide substrate, depending on the applied current. A hypothesis regarding the driving physical phenomena that lead the microparticles to fragment into NPs is discussed. Fabrication of gold NPs in the SEM provides a more cost-effective option as compared to the established method in the TEM. T2 - PhD Seminar CY - Berlin, Germany DA - 26.11.2023 KW - Electron-beam-induced modification KW - Gold nanoparticles KW - Fabrication method KW - Scanning electron microscope KW - Nano-assemblies PY - 2023 AN - OPUS4-59080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Platform MaterialDigital Core Ontology (PMDco): A Community Driven Mid-Level Ontology in the MSE Domain N2 - Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific. The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications. T2 - Patents4Science CY - Berlin, Germany DA - 05.10.2023 KW - Knowledge Representation KW - Semantic Interoperability KW - FAIR data management KW - Knowledge graph and ontologies KW - PMD Core Ontology PY - 2023 AN - OPUS4-58507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - News from the working area - Semantic Interoperability N2 - This presentation provides a comprehensive overview of recent developments and the current status within the Semantic Interoperability work area, with a particular emphasis on the advancements related to the Platform MaterialDigital Core Ontology (PMDco). The presentation will delve into the collaborative and community-supported curation process that has been instrumental in shaping PMDco. Additionally, we will introduce the innovative Ontology Playground, showcasing its role in fostering experimentation and exploration within the realm of ontology development. T2 - MaterialDigital Vollversammlung CY - Karlsruhe, Germany DA - 21.09.2023 KW - Semantic Representation KW - FAIR data management KW - Semantic Interoperability KW - Knowledge graph and ontologies KW - PMD Core Ontology KW - MaterialDigital PY - 2023 AN - OPUS4-58422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - Transitions from scale-free to scale-dependent fluctuations in plasticity N2 - Plastic deformation in crystals is mediated by the motion of line defects known as dislocations. For decades, dislocation activity has been treated as a homogeneous, smooth continuous process that relies on well-average quantities. However, it is now recognized that plasticity can be determined by long-range correlated and intermittent collective dislocation activity, known as avalanches. These abrupt plastic fluctuations often exhibit pure power-law scaling or truncated power-law scaling, which indicates at least some degree of scale-free dislocation behavior. Intriguingly, such statistical signatures can persist across scales exceeding those of the material’s microstructure, raising the question of what relationship there may be between structure and long-range correlated dislocation activity that underlie power-law scaling. In this talk, we address this question by highlighting examples in which a transition from scale-free to scale-dependent plastic deformation is observed either due to changing external testing conditions (stress-state or temperature) or by tuning the microstructure. In particular, we will focus on the details of the temperature-driven change, that demonstrates how scale-free intermittent flow in body-centered cubic Nb is progressively quenched out with decreasing temperature. The plastic response of Nb is shown to be bimodal across the studied temperature regime, with conventional thermally-activated smooth plastic flow coexisting with sporadic bursts controlled by athermal screw dislocation activity, thereby violating the classical notion of temperature-dependent screw dislocation motion at low temperatures. An abrupt increase of the athermal avalanche component is identified at the critical temperature of the material. We combine the experimental observations with 3D dislocation dynamics simulations, identify a possible origin to athermal screw activity, and discuss the co-existence scale-free and scale-dependent plasticity. T2 - Cairo Symposium on The Physics of Metal Plasticity CY - Cairo, Egypt DA - 05.09.2023 KW - Plastic deformation KW - Dislocations KW - Avalanches PY - 2023 AN - OPUS4-60648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Birkholz, Henk A1 - Bayerlein, Bernd T1 - Evolution of the PMD Core Ontology (PMDco) Towards ISO/IEC 21838-2:2021 Basic Formal Ontology (BFO) N2 - Knowledge representation in the materials science and engineering (MSE) domain is a vast and multi-faceted challenge: Overlap, ambiguity, and inconsistency in terminology are common. Invariant and variant knowledge are difficult to align cross-domain. Generic top-level semantic terminology often is too abstract, while MSE domain terminology often is too specific. In this presentation, an approach how to maintain a comprehensive and intuitive MSE-centric terminology composing a mid-level ontology–the PMD Core Ontology (PMDco)–via MSE community-based curation procedures is shown. The PMDco is designed in direct support of the FAIR principles to address immediate needs of the global experts community and their requirements. The illustrated findings show how the PMDco bridges semantic gaps between high-level, MSE-specific, and other science domain semantics, how the PMDco lowers development and integration thresholds, and how to fuel it from real-world data sources ranging from manually conducted experiments and simulations as well as continuously automated industrial applications. T2 - MSE Congress 2024 - Materials Science and Engineering CY - Darmstadt, Germany DA - 24.09.2024 KW - Ontology KW - Semantic Interoperability KW - Knowledge representation KW - FAIR Data Management KW - PMD Core Ontology PY - 2024 AN - OPUS4-61141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisenbart, Miriam T1 - Digitalization of a high-throughput alloy development process N2 - Digitalization is nowadays the central key in developing pharmaceutical products, but it also becomes increasingly important in computer aided material development. In this work it is presented how a collaborative ontology development for the alloy development process is approached and a workflow for chemical optimization of copper alloys is introduced. This is done by employing a combination of a high-throughput alloy development method [1] with the calculation of the corresponding phase compositions. The work presented here is part of the publicly funded project KupferDigital. The project is associated with the innovation platform MaterialDigital (PMD) and focusses on the digitalization of processes as well as knowledge representation along the life-cycle of copper and copper alloys. One part of this life cycle is the alloy development of copper alloys, in this case the alloy development employing a high throughput method based on diffusion couples. The alloy development process can be further broken down into several typical material processing steps such as casting, diffusion welding and annealing. As part of the copper life cycle, the constitution and the properties of an alloy play an important role for processes further down the road during product manufacturing and service life and are also crucial for the recycling properties of the alloy. It is therefore important to, on the one hand, communicate data concerning properties, process history and constitution to the following stations of the life cycle, on the other hand, it is also elementary for the material scientist to be aware of the recycling properties of the alloys constituents. This motivates sharing of data along the life cycle and the development of ontology based data spaces, where life-cycle information can be linked across all involved domains. As part of the alloy development process, it is presented how experimental data created at fem are shared using linked data and ontologies with an example based on the digital representation of the chemical composition of copper alloys further processed by CALculation of PHAse Diagrams (CALPHAD) at the Fraunhofer IWM. The calculation results are used to correlate measured hardness data with the equilibrium phases of the alloys. Selected Compositions are cast and heat treated and subjected to mechanical testing at BAM and the resulting mechanical property-data are again linked to the measured and simulated data from the alloy development process. T2 - MSE2024 CY - Darmstadt, Germany DA - 24.09.2024 KW - Digitalization KW - Alloy development PY - 2024 AN - OPUS4-61150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Höhne, Patrick T1 - Optimized spray granules for dry pressing by means of slurry destabilization and ultrasonic atomization N2 - The homogeneous introduction of organic additives is a prerequisite for good processability of ceramic powders during dry pressing. The addition of organic additives by wet route via ceramic slurries offers advantages over dry processing. The organic content can be reduced and a more homogeneous distribution of the additives on the particle surface is achieved. In addition to the measurements of zeta potential and viscosity, sedimentation analysis by optical centrifugation was also tested and successfully used to characterize the ceramic slurries and accurately evaluate of the suitability of different types, amounts, and compositions of organic additives. Spray drying of well-stabilized slurries usually results in mostly hollow granules with a hard shell leading to sintered bodies with defects and reduced strength and density. By purposefully degrading the slurry stability after dispersion of the ceramic powder, the drying behavior of the granules in the spray drying process and thus the granule properties can be influenced. Destabilization of the slurry and thus partial flocculation was quantified by optical centrifugation. Spray drying of the destabilized alumina slurries resulted in "non-hollow" granules without the detrimental hard shell and thus improved granule properties. Further improvement of the granules was achieved by installing ultrasonic atomization in the spray dryer. A narrower granule size distribution was achieved, which had a positive effect on, among other things, the flowability of the granules. Specimens produced from this granules had fewer defects of smaller size, leading to better results for the density and strength of the sintered bodies. The observations made for alumina could be transferred to zirconia and as well to ZTA with 20 wt% zirconia. T2 - Ceramics in Europe 2022 CY - Krakau, Poland DA - 10.07.2022 KW - Ultrasound KW - Spray drying KW - Slurry PY - 2022 AN - OPUS4-56171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hemmleb, M. T1 - Integrated topographic SEM imaging for software assisted fractography N2 - The aim of a fractographic investigation is the evaluation of macroscopic and microscopic fracture surface characteristics and, as a result, the determination of the fracture mechanism of a component from a failure case. The basis for such evaluations of fracture characteristics comes from actual comparative mechanical testing and from the literature. A fractographic analysis can be very complex and, in any case, requires considerable experience. Machine learning methods enables the quantitative determination of fracture characteristics and fracture mechanisms utilizing digitized expert knowledge [1]. Although the application of SE images provides promising results, additional information is required to obtain reliable solutions. As expected, BSE and 3D information helps to improve the classification (Fig. 1). But only a fast, widely integrated, and automated topography measurement can provide the required amount of referenced surface data for the application of machine learning methods. To fulfil these requirements, topographical data are obtained from a BSE detector with four symmetric segments (4Q-BSE) using shape-from-shading technology [2]. Surface height calculation is performed live during image acquisition and provides immediate feedback in three dimensions. All available signals (SE, BSE and more if applicable) are recorded simultaneously together with the surface topography and stored in a multichannel data file. This guaranties the same geometrical reference for all data, which is required for further analysis (Fig. 2). When applying machine learning methods to topographic data together with SEM images, topographic information must be provided as depth image. Consequently, a unique height scale is required for all applied data with different magnifications. This requires a calibrated height measurement, which is ensured with the integrated 3D calibration of the topographic acquisition and a dedicated calibration sample. Thus, a large number of data sets from different fracture samples was generated and used as training data for machine learning. T2 - 16th Multinational Congress on Microscopy CY - Brno, Czech Republic DA - 04.09.2022 KW - Fractography KW - Machine Learning KW - Topography PY - 2022 AN - OPUS4-55937 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmies, Lennart T1 - Using Machine Learning and Topographic SEM Imaging for Software Assisted Fractography N2 - The aim of a fractographic investigation is the evaluation of macroscopic and microscopic fracture surface characteristics and, as a result, the determination of the fracture mechanism of a component from a failure case. The basis for such evaluations of fracture characteristics comes from actual comparative mechanical testing and from the literature. A fractographic analysis can be very complex and, in any case, requires considerable experience. In the IGF project "iFrakto", software is being developed that quantitatively determines fracture characteristics and fracture mechanisms utilizing digitized expert knowledge, machine learning, and standard 2D and topographical data from SEM imaging. Topographical data are obtained from 4QBSE detector using shape-from-shading technology. In the medium term, a software tool should provide knowledge-based suggestions for the evaluation of fracture surfaces in real time during SEM work or at subsequent evaluation. As a basis for this, round robins were carried out among fractographers in order to create a knowledge base, to query the practice-relevant requirements for such tools and to carry out first practical tests. Actual results are presented and the relevance of the evaluation strategy is evaluated. T2 - Material Science and Engineering 2022 CY - Darmstadt, Germany DA - 27.9.2022 KW - Fractography KW - Machine Learning KW - Topography PY - 2022 AN - OPUS4-55938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Digital Transformation in Materials Science: Insights from Platform MaterialDigital (PMD), Tensile Test Ontology (TTO), Electronic Lab Notebooks (ELN) N2 - The digital era has led to a significant increase in innovation in scientific research across diverse fields and sectors. Evolution of data-driven methodologies lead to a number of paradigm shifts how data, information, and knowledge is produced, understood, and analyzed. High profile paradigm shifts in the field of materials science (MS) include exploitative usage of computational tools, machine learning algorithms, and high-performance computing, which unlock novel avenues for investigating materials. In these presentations, we highlight prototype solutions developed in the context of the Platform MaterialDigital (PMD) project that addresses digitalization challenges. As part of the Material Digital Initiative, the PMD supports the establishment of a virtual materials data space and a systematic handling of hierarchical processes and materials data using a developed ontological framework as high priority work items. In particular, the mid-level ontology PMDco and its augmentation through application-specific ontologies are illustrated. As part of the conclusion, a discussion encompasses the evolutionary path of the ontological framework, taking into account standardization efforts and the integration of modern AI methodologies such as natural language processing (NLP). Moreover, demonstrators illustrated in these presentations highlight: The integration and interconnection of tools, such as digital workflows and ontologies, Semantic integration of diverse data as proof of concept for semantic interoperability, Improved reproducibility in image processing and analysis, and Seamless data acquisition pipelines supported by an ontological framework. In this context, concepts regarding the application of modern research data management tools, such as electronic laboratory notebooks (ELN) and laboratory information management systems (LIMS), are presented and elaborated on. Furthermore, the growing relevance of a standardized adoption of such technologies in the future landscape of digital initiatives is addressed. This is supposed to provide an additional basis for discussion with respect to possible collaborations. T2 - NIST Seminar Series CY - Gaithersburg, MD, USA DA - 11.06.2024 KW - Semantic Data KW - Plattform Material Digital KW - Digitalization KW - Data Interoperability KW - NIST KW - Tensile Test Ontology KW - Elctronic Lab Notebook PY - 2024 AN - OPUS4-60392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Structure-property correlations in RE-doped fluoride-phosphate glasses sought by NMR, EPR & PL N2 - As the development of optimized glass compositions by traditional trial-and-error methods is laborious, expensive, and time consuming, it is desirable to gather fundamental understanding of structure and to develop structure-property relation models, which allow best and faster choices. Particularly, when it comes to optical applications of glasses doped with emissive trivalent rare earth ions (RE), the chemical environmental around the ions will have a direct influence on the radiative/non-radiative emission probabilities. The vibrational environment and the chemical nature of the bonds in the first coordination sphere of the ions can be tailored, to some extent, based on structural information given by magnetic resonance (NMR and EPR) techniques associated to Raman and photophysical characterization. For the past 5 years, one of the interests of my research group at the University of São Paulo, in Brazil, has been the development of high-density fluoride-phosphate glasses as promising UV and X-ray scintillator materials. The targeted glasses offer a lower vibrational energy, less hygroscopic fluoride environment for the RE ions whereas the phosphate network provides improved mechanical and chemical stability than a purely fluoride glass matrix. Different sets of glasses, based on the compositional system (Ba/Sr)F2-M(PO3)3-MF3-(Sc/Y)F3 where M = Al, In, Ga, and the phosphate component is substituted by the fluoride analogue in 10-30 mol%, were investigated, using Sc3+, Y3+, and the Eu3+ and Yb3+ dopants, as structural probes. Overall, results show that the desired RE coordination by F, at a given F/P ratio, is proportional to the atomic mass of M (In> Ga> Al) and that the Ga- and In- based systems differ from the Al- one by near absence of P-O-P network linkages i.e, the network structures are dominated by Ga-O-P or In-O-P linkages as evidenced by 31P MAS-NMR and Raman. These results are nicely corroborated by observation of decreased intensity in the vibronic band of Eu3+ and significant increase in the excited state lifetime values. Radioluminescence studies were carried out for a series of In-based glasses doped with Ce3+ and Tb3+ yielding intense emissions in the blue and green, respectively, compatible to the spectral region of highest sensitivity of radiation sensor detectors. The aim of the presentation is to show how powerful the combination of NMR, EPR, Raman and PLE spectroscopies can be to provide structural information and to present the perspectives for their introduction in the research agenda of Division 5.6 – Glass, which I now lead, at the Federal Institute for Materials Research and Testing (BAM) in Berlin, Germany. T2 - GOMD 2024 - Glass and Optical Division Meeting, ACerS CY - Las Vegas, NV, USA DA - 19.05.2024 KW - Glass Digital KW - Glasses KW - Robotic melting PY - 2024 AN - OPUS4-60357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Structure-property correlations in RE-doped fluoride-phosphate glasses for scintillation N2 - As the development of optimized glass compositions by traditional trial-and-error methods is laborious, time consuming, and expensive, it is desirable to develop glass compositions based on a fundamental understanding of the glass structure and to establish structure-property relation models. Particularly, when it comes to optical applications of glasses doped with emissive trivalent rare earth ions (RE), the chemical environmental around the ions will have a direct influence on the radiative/non-radiative emission probabilities. The local vibrational environment and the chemical nature of the bonds in the first coordination sphere of the ions can be tailored, to good extent, based on structural information given by magnetic resonance techniques (NMR and EPR), associated to Raman and photophysical characterization. For the past 5 years, while still employed at the University of São Paulo, in Brazil, one of the interests of my research group has been the development of high-density fluoride-phosphate glasses as promising UV and X-ray scintillator materials. The targeted glasses offer a lower vibrational energy, less hygroscopic fluoride environment for the RE ions whereas the phosphate network provides better mechanical and chemical stability than a purely fluoride glass matrix. Different sets of glasses, based on the compositional system (Ba/Sr)F2-M(PO3)3-MF3-(Sc/Y)F3 where M = Al, In, Ga, and the phosphate component is substituted by the fluoride analogue in 10 - 30 mol%, were investigated, using Sc3+, Y3+, and the Eu3+ and Yb3+ dopants, as structural probes. Overall, results show that the desired RE coordination by fluorine, at a given F/P ratio, is proportional to the atomic mass of M (In> Ga> Al) and that the Ga- and In- based systems differ from the Al- one by near absence of P-O-P network linkages. That is, the network structures are dominated by Ga-O-P or In-O-P linkages, as evidenced by 31P MAS-NMR and Raman. These results are nicely corroborated by observation of decreased intensity of the vibronic band in Eu3+-doped glasses and marked increase in excited state lifetime values. Radioluminescence studies were carried out for a series of In-based glasses doped with Ce3+ and Tb3+, yielding intense emissions in the blue and green, respectively, compatible to the spectral region of the highest sensitivity of radiation sensor detectors. The aim of the presentation is to show how powerful the NMR and EPR techniques can be to provide decisive structural information, and to present the research perspectives in my new role as the Head of Division 5.6 – Glass at BAM. T2 - Fachausschusses I „Physik und Chemie des Glases“, DGG CY - Jena, Germany DA - 02.11.2023 KW - Structure-property correlation KW - Fluoride phosphate glasses KW - Scintillators KW - High energy radiation PY - 2024 AN - OPUS4-60360 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Galleani, Gustavo A1 - Lodi, Thiago A1 - Merízio, Leonnam A1 - de Jesus, Vinícius A1 - de Camargo, Andrea Simone Stucchi T1 - Scintillators, persistent luminescent and white light emitters: Progresses on UV and X-ray converting glasses and composites N2 - Recently, detection and conversion of high energy radiation such as ultraviolet and X-rays has gained renewed attention. In part, technological applications in radioimaging and tomography have developed considerably as to allow lower dosages and higher resolutions, which require optimized scintillators and dosimeters. On the other hand, the increasing effort to reduce carbon footprint in energy production has triggered an intensive search for materials that can be excited with sunlight, ranging from photocatalysts to solar concentrators. At LEMAF – Laboratory of Spectroscopy of Functional Materials at IFSC/USP, we have been developing bulk glasses, polycrystalline and composite materials designed to target both challenges and, in this work an overview of recent progresses and of the state of art of these materials will be given. For instance, the few available comercial scintillators are crystalline materials with costly and time consuming growth which hinders the development of new compositions. Glasses and glass ceramics, such as the NaPGaW composition developed in our lab, present high density, very good optical properties and high chemical stability which allow them radioluminescent response when doped with low concentrations of Ce3+, Eu3+ and Tb3+ offering a promise as alternatives to crystal scintillators. On the other hand, phosphor in glass (PiG) composites based on the persistent luminescent polycrystalline material Sr2MgSi2O7:Eu2+,Dy3+ (SMSO) embedded into NaPGa glasses offer interesting perspectives for the of UV light into visible, useful for white light generation (lighting), improved harvesting and conversion of solar light when coupled to c-Si PV cells and photocatalysis. These and other examples will be discussed. The glasses are prepared through the conventional melt quenching technique, followed by controlled heating when glass ceramics are desired. The persistent luminescent phosphor is prepared by the microwave assisted technique (MAS) much faster and with considerable energy consumption reduction than in the usual solid state synthesis. The materials are characterized from the structural, morphological and spectroscopic (optical – UV-Vis, PL, PLE, and structural – NMR, EPR) points of view such that structure-property correlations are constantly sought to feedback synthesis and processing. Fig. 1, illustrates two examples of scintillator glasses doped with Tb3+ and PiG composites doped with Eu2+ and Dy3+. T2 - 11th International Conference on f Elements (ICFE-11) CY - Strasbourg, France DA - 22.08.2023 KW - Scintillators KW - Persistent luminescence KW - White light emitters PY - 2023 AN - OPUS4-60361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Optical properties of dental ceramics: Characterization via UV-Vis and photoluminescence spectroscopies N2 - When it comes to dental treatments, success is not only measured by attained functionality but, to a large extent, the associated aesthetics. This can become challenging for certain restorations and implants due to the complex optical characteristic of a tooth, which reflects, absorbs, diffuses, transmits, and even emits light. Thus, to get acceptable aesthetic results, favourable shade matching of ceramic restorations and implants should be achieved by strict control of optical response, which translates into a materials design question. Optical response is affected by several factors such as the composition, crystalline content, porosity, additives, grain size and the angle of incidence of light on the dental ceramics. The properties to be characterized are colour (and its stability), translucency, opalescence, refractive index, and fluorescence. Several techniques can be applied for the characterization of these properties and in this presentation, an overview will be given. Moreover, particular emphasis will be given on the capacitation of less familiarized public to UV-Vis absorption and photoluminescence (PLE) spectroscopies that are versatile and widely employed for functional and structural characterization of glasses and glass ceramic materials. T2 - 2nd BAYLAT Workshop of CERTEV - FAU CY - Nuremberg, Germany DA - 04.12.2023 KW - Optical properties KW - Dental ceramics KW - Optical spectroscopy PY - 2023 AN - OPUS4-60364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Glass Digitalization: Contributions from BAM N2 - An overview of the Glass Digitalization efforts at BAM, within the framework of the Glass Digital consortium, was given. From the development of the robotic melting device to the ML capabilities, a description of the different stages of the developments and roles of project partner was presented. T2 - GlaCerHub Melting Day CY - Oponice, Slovakia DA - 12.06.2024 KW - Glass Digital KW - Robotic glass melting KW - Digitalization PY - 2024 AN - OPUS4-60365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Gender equality in Sciences: Let´s teach our girls to be brave! N2 - A panorama of the global gender gap scenario in sciences, specially STEM, was given to illustrate the need for urgent actions (and suggestions of them) to correct biased treatment and promote females in their scientific careers. T2 - FunGlass School CY - Oponice, Slovakia DA - 10.06.2024 KW - Gender gap KW - Women in science KW - Female noble prize winners PY - 2024 AN - OPUS4-60366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Spectroscopy Lectures N2 - As a guest professor of FUNGLASS, I delivered 3 lectures on spectroscopy to the Graduate School Program, the postdoctoral fellows and other researchers: 1) Introduction to spectroscopy applied to solid state materials (with focus on glass and glass ceramics); 2) Vibrational spectroscopy (Infrared and Raman); 3) Electron Paramagnetic Resonance T2 - FunGlass CY - Trencín, Slovakia DA - 03.06.2024 KW - Spectroscopy KW - Radiation-matter interaction KW - FT-IR KW - Raman KW - EPR PY - 2024 AN - OPUS4-60367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - From guest scintillators to luminescent host-guest hybrid materials and nanoparticles: Contributions from LEMAF N2 - An overview of the research work conducted at LEMAF - the laboratory of spectroscopy of functional materials in IFSC/USP Brazil under my leadership, before I joined BAM was given. T2 - FunGlass Graduate Program School CY - Oponice, Slovakia DA - 10.10.2023 KW - Multifunctional nanoparticles KW - Structure property correlations KW - Host-guest hybrid materials KW - Scintillators KW - Persistent luminescent KW - Phosphors KW - Composite materials PY - 2024 AN - OPUS4-60368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Gender equality in sciences: Let's teach our girls to be brave! N2 - A global panorama of the Gender Gap in Sciences was presented along with recommendations on how to remediate unequal treatment of females in Science, and to prepare future generations for gender equality. T2 - Lunch Talk - Women@DGM: Gender Mindsets/Bias in an International Context CY - Online meeting DA - 14.06.2024 KW - Gender gap PY - 2024 AN - OPUS4-60369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Optical properties of glasses and ceramics N2 - Optical glasses and glass ceramics are present in many devices often used in our daily routine, such as the mobile phones and tablets. Since the 1960´s with the development of glass lasers, and more recently, within the search for efficient W-LEDs, sensors and solar converters, this class of materials has experienced extreme research progress. In order to tailor a material for such applications, it is very important to understand and characterize optical properties such as refractive index, transmission window, absorption and emission cross sections, quantum yields, etc. These properties can often be tuned by appropriate compositional choice and post-synthesis processing. In this lecture we will discuss the optical properties of glasses and glass ceramics, relevant to that end. T2 - 2nd CeRTEV Glass School CY - São Carlos, SP, Brazil DA - 22.04.2024 KW - Optical properties of glasses and ceramics PY - 2024 AN - OPUS4-60370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Digital Transformation in Materials Science: Insights From the Platform MaterialDigital (PMD) N2 - The digital era has led to a significant increase in innovation in scientific research across diverse fields and sectors. Evolution of data-driven methodologies lead to a number of paradigm shifts how data, information, and knowledge is produced, understood, and analyzed. High profile paradigm shifts in the field of materials science (MS) include exploitative usage of computational tools, machine learning algorithms, and high-performance computing, which unlock novel avenues for investigating materials. In these presentations, we highlight prototype solutions developed in the context of the Platform MaterialDigital (PMD) project that addresses digitalization challenges. As part of the Material Digital Initiative, the PMD supports the establishment of a virtual materials data space and a systematic handling of hierarchical processes and materials data using a developed ontological framework as high priority work items. In particular, the mid-level ontology PMDco and its augmentation through application-specific ontologies are illustrated. As part of the conclusion, a discussion encompasses the evolutionary path of the ontological framework, taking into account standardization efforts and the integration of modern AI methodologies such as natural language processing (NLP). Moreover, demonstrators illustrated in these presentations highlight: The integration and interconnection of tools, such as digital workflows and ontologies, Semantic integration of diverse data as proof of concept for semantic interoperability, Improved reproducibility in image processing and analysis, and Seamless data acquisition pipelines supported by an ontological framework. In this context, concepts regarding the application of modern research data management tools, such as electronic laboratory notebooks (ELN) and laboratory information management systems (LIMS), are presented and elaborated on. Furthermore, the growing relevance of a standardized adoption of such technologies in the future landscape of digital initiatives is addressed. This is supposed to provide an additional basis for discussion with respect to possible collaborations. T2 - NIST Seminar on Digital Transformation CY - Gaithersburg, MD, USA DA - 11.06.2024 KW - Digital Transformation KW - Research Data Management KW - Ontology KW - Reusability KW - FAIR PY - 2024 AN - OPUS4-60381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Advancing Digital Workflows in Materials Science: The Role of PMDco in Data Integration and Semantic Representation N2 - The field of Materials Science and Engineering (MSE) is undergoing a transformative shift towards digitalization, emphasizing the need for structured and interoperable data management. The Platform MaterialDigital Core Ontology (PMDco), now in version 3.0, addresses these challenges by providing a robust mid-level semantic framework. PMDco bridges the gap between abstract high-level ontologies, such as the Basic Formal Ontology (BFO) standardized in ISO/IEC 21838-2, and highly specific domain terminologies to ensure consistency and interoperability across diverse MSE applications. Developed through MSE community-based curation, PMDco facilitates the integration of real-world data from experiments, simulations, and industrial processes. This presentation will explore PMDco's role in enabling advanced digital workflows and its integration into demonstrators within the Platform MaterialDigital (PMD) initiative. Highlighted use cases include the semantic representation of tensile test data in compliance with ISO 6892-1:2019-11, utilizing the corresponding tensile test ontology (TTO) built on PMDco. Through an electronic laboratory notebook (ELN), data from experiments performed by undergraduate students were transformed into machine-actionable knowledge graphs, demonstrating the potential for education and fully digitalized experimental procedures. Additionally, a possible extension of PMDco as a linking point for semantically representing simulation data will be presented, aligning with the focus of VMAP. This includes linking experimental, simulation, and computational datasets to create comprehensive, FAIR-compliant knowledge ecosystems. By showcasing best practices in data acquisition, semantic integration, and knowledge graph generation, this presentation underscores PMDco’s versatility and its critical role in advancing digital MSE workflows. T2 - VMAP User Forum 2025 CY - Sankt Augustin, Germany DA - 18.02.2025 KW - Semantic Data KW - Data Integration KW - Digitalization KW - Data Interoperability KW - PMD Core Ontology PY - 2025 AN - OPUS4-62607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Saber, Yassin A1 - Clague, Leighton T1 - Automated Fused Filament Fabrication of Ceramics and Metals - Remote and in Space N2 - Component manufacturing in remote (i.e., geographically isolated) settings poses significant challenges where access to conventional manufacturing facilities is limited or non-existent. Fused Filament Fabrication (FFF) enables the rapid manufacturing of plastic, metallic and ceramic components with complex geometries. Ceramic and metallic parts formed by FFF require subsequent debinding and sintering to reach full density. Debinding and sintering are typically executed in separate steps with different equipment, necessitating extensive human handling which hinders process automation and may be challenging for the operator in isolated environments. Here an innovative approach is presented: the integration of all process steps into a single, fully automated system, streamlining the process and minimizing human involvement. Our system combines a dual extrusion filament printer with a porous and heat-resistant ceramic print bed. The porous print bed enables mechanical interlocking of the first printed layers, ensuring adhesion and structural integrity during FFF. Ceramic and metallic parts are printed onto thin sacrificial rafts, which are built using an interface material with the same binder as the loaded filament. After the print is completed, the heat-resistant print bed with all parts is transferred seamlessly with a carrier system into a high-temperature furnace for debinding and sintering. During sintering the sacrificial raft is disintegrated, allowing for unconstrained sintering and easy removal of the finished parts. In conclusion, our integrated approach enables significant advancements in the fabrication of complex ceramic or metallic components in remote environments with increased efficiency and minimal human handling. T2 - AM Forum 2025 CY - Berlin, Germany DA - 17.03.2025 KW - Fused Filament Fabrication KW - Ceramics KW - Metalls KW - Process automation PY - 2025 AN - OPUS4-62745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Digital Transformation in Materials Science through Semantic Technologies and Knowledge Graphs N2 - The field of materials science is undergoing a transformative shift driven by digitalization. In this respect, semantic and AI technologies are paving the way for advancements in materials development, design, and optimization while leaping towards an Industry 4.0 environment. Addressing the dual challenges of quality assurance and data interoperability, this presentation examines the integration of semantic technologies and knowledge representation methods. By adhering to FAIR principles, this approach enhances data management, storage, and reuse. That way, both machine-actionable and human-understandable data structures crucial for digital research environments are fostered. This presentation focuses on the ‘platform MaterialDigital’ (PMD) initiative, which aims to support efforts from both industrial and academic sectors to solve digitalization challenges and implement sustainable digital solutions. Besides establishing structures to create virtual material data spaces, PMD develops solutions for systematizing and unifying the handling of hierarchical, process-dependent material data. Semantic technologies play a crucial role in digitalization efforts as they enable the storage, processing, and querying of data in a contextualized form. Therefore, the development and prototypical application of the PMD Core Ontology 3.0 (PMDco 3.0) tailored for materials science is highlighted. This includes the design and documentation of graph patterns that may be compiled into rule-based semantic shapes. Its integration into daily lab life is demonstrated through its application to electronic lab notebooks (ELN). This illustrates potentials of standardized protocols and automation-ready solutions for managing diverse experimental data across different sources. Outlining best practices and illustrating the possibilities that semantic technologies bring to modern labs, examples from materials processing and mechanical testing will underscore how knowledge graphs bridge the gap between data and decision-making in materials science, with potential for increased productivity and streamlined workflows across the field. T2 - Materials Week 2025 CY - Frankfurt am Main, Germany DA - 03.04.2025 KW - Semantic Data KW - Data Integration KW - Digitalization KW - Data Interoperability KW - PMD Core Ontology PY - 2025 AN - OPUS4-62866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rodricks, Carol T1 - Advancing Sustainable Composites: Challenges and innovations N2 - With the increased use of carbon fibre polymer matrix composites comes the important question of their management at the end of their life cycle. Given the high costs associated with carbon fibre production, recycling carbon fibres from composite waste is a desirable source of reinforcing fibres for new applications. However, current recycling methods result in recycled carbon fibres that are short with little to no orientation which can only be used in applications requiring intermediate strength at a fraction of the potential of the continuous, aligned virgin fibres. Thus, a method to recycle fibres with their original length and orientation intact is vital to truly realising a circular economy for carbon fibre polymer composites. Our research introduces a novel hierarchical composite aimed at preserving the length and orientation of carbon fibres on recycling. Virgin carbon fibres are encapsulated in an insoluble epoxy matrix to form tapes that serve as the primary units of the hierarchical structure. The primary epoxy matrix protects the fibres from chemical and environmental elements while maintaining their permanent orientation. The primary tape units are subsequently embedded in a secondary recyclable matrix polymer to make larger composite structures. Elium, a thermoplastic that dissolves in acetone and has mechanical properties comparable to epoxy, was chosen as the secondary matrix of choice in this study. This approach aims to achieve a composite that is mechanical equivalent to thermoset composites while facilitating easy recycling with minimal impact on the fibres in the primary unit. T2 - Materials Week 2025 CY - Frankfurt am Main, Germany DA - 02.04.25 KW - Recycling KW - Carbon fibres KW - Mechanical testing KW - Polymer-matrix composites (PMCs), micromechanics KW - Elium PY - 2025 AN - OPUS4-63004 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago T1 - Short fatigue crack propagation in L-PBF 316L stainless steel N2 - Fracture mechanics is a key to fatigue assessment in AM metal components. Short fatigue cracks are initiated at defects and pronounced surface roughness intrinsic to AM. The subsequent crack-propagation is strongly influenced by microstructural interactions and the build-up of crack-closure. The aim of the present study is to give an insight into short-crack propagation in AM-metals. Fatigue crack propagation resistance curves were determined experimentally for AISI 316L manufactured by Laser Powder Bed Fusion (L-PBF) which was heat treated at three different temperatures. Differences in the build-up of the fatigue-crack propagation threshold in between the L-PBF specimens and compared to wrought material are due to the residual stress states, a pronounced roughness of the crack-faces in the L-PBF specimens and phase transformation in the vicinity of the crack-tip, resulting in increased crack-closure. This, together with crack-branching found along the crack path, enhances the resistance to the propagation of fatigue cracks. T2 - ASTM International Conference on Additive Manufacturing 2020 CY - Online meeting DA - 16.11.2020 KW - Additive Manufacturing KW - Cyclic R-Curve KW - Component assessment KW - L-PBF KW - 316L KW - Residual Stress KW - Fatigue Crack Growth PY - 2020 AN - OPUS4-51585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane T1 - Novel insights into high temperature corrosion phenomena by advanced X-ray methods N2 - A variety of materials of technological interest change their properties through contact with reactive media. Solid-gas reactions lead to a variety of reaction products on the surfaces and internal interfaces. The observation of nucleation and growth processes in the environment where they occur (in situ) from a chemical-structural perspective is especially challenging for aggressive atmospheres. The talk presents innovative approaches to study corrosion mechanisms using advanced X-ray methods. Using energy dispersive X-ray diffraction and X-ray absorption spectroscopy in different tailor made environmental reaction chambers, valuable insights into high temperature oxidation and sulfidation processes were gained. Fe-based alloys were exposed to hot and reactive atmospheres containing gases like SO2, H2O and O2 at 650°C. During the gas exposure the tailor made reaction chambers were connected to a high energy diffraction end station at the synchrotron. The crystallization and growth of oxide and sulfide reaction products at the alloy surfaces were monitored by collecting full diffraction pattern every minute. Careful examination of shape and intensity of phase-specific reflections enabled to a detailed view on growth kinetics. These studies showed, oxides are the first phases occurring immediately after experimental start. As soon as reactive gas media enter the chamber, the conditions change and different reaction products, such as sulfides start to grow. A comparison of different gas environments applied, illustrated the differences in the type of reaction products. The in situ observation of high temperature material degradation by corrosion made it possible to study the contribution of phases, which are not stable at room temperature. For instance, wuestite (Fe1-xO), was frequently observed at high temperatures in humid gases on Fe with 2 wt.% and 9 wt.% chromium, but not at room temperature. The strength of the occurrence of this phase additionally explains why, despite a higher Cr content, ferritic alloys with 9 wt.% Cr in a challenging atmosphere prevent the intrinsic formation of protective layers. The in situ observations were supplemented by careful considerations of thermodynamic boundary conditions and detailed post characterization by classical metallographic analysis. Additionally, the structure and chemistry of the dominant oxide layers were evaluated using X-ray absorption near edge structure spectroscopy. The talk will give an overview about chances and challenges for studying high temperature corrosion phenomena by advanced X-ray methods. T2 - MRS Spring Meeting CT08.02.01 CY - Online Meeting DA - 18.04.2021 KW - XRD KW - Spectroscopy KW - Corrosion KW - High temperature KW - In-situ PY - 2021 AN - OPUS4-52486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Sample Preparation of Nano-Powders for Particle Size Determination N2 - The use of increasingly finer starting powders up to nanopowders can also be observed in the field of ceramics. Their advantages consist, for example, in their lower activation energy, an increase in strength or unique optical properties. However, handling and characterization of the powders are much more difficult. The main reason for this is the very high adhesive forces between the particles and between particles and other surfaces, too. Therefore, submicron and even more so nanoparticles tend to agglomerate and their separation into primary particles during sample preparation prior to particle sizing is of particular challenge. A representative measurement sample is only obtained when it no longer contains agglomerates. The evaluation of the dispersion process and a decision on whether it was successful thus increases in importance for the reliability of the measurement results of particle sizing. The presentation uses examples to show possible approaches and provides information on possible sources of error. It is shown that successful granulometric characterisation of fine powders requires both an improved dispersion technique and very often an effective combination of two or more measurement methods. T2 - 96. Jahrestagung der Deutschen Keramischen Gesellschaft CY - Online Meeting DA - 19.04.2021 KW - Agglomerates KW - Nano-powder KW - Dispersion process PY - 2021 AN - OPUS4-52503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Wencke T1 - High temperature corrosion of high (HEA) and medium (MEA) entropy alloys N2 - The high-temperature corrosion behavior of the medium-entropy alloy Cr33Co33Ni33 (MEA) and the high-entropy alloy Fe20Cr20Co20Ni20Mn20 (HEA) in a mixed gas atmosphere of 10% H2O-2% O2 -0.5% SO2 + Ar as carrier gas [Vol.%] at 800 °C with duration times of t = 24h, 48h and 96h was investigated. Both alloys have a single-phase fcc microstructure. The oxidation kinetics of the HEA-CrMnFeCoNi roughly followed a linear rate law and a slow oxide growth was observable for the MEA-CrCoNi. The scale thickness of the corrosion layer in the quinary alloy increased with exposure time, while the scale thickness in the ternary alloy remained constant at around 1 µm. The MEA-CrCoNi developed a protective Cr2O3 layer with minor buckled parts. Co,Ni-chromite (Co,Ni)Cr2O4 was detected by XRD in minor amounts. The scale on HEA-CrMnFeCoNi displayed a triplex structure of a thin, continuous, inner Cr2O3 layer, a dense, intermediate Mn3O4 layer, and a thick, outer, porous layer consisting of Mn3O4 and MnSO4. Sulphides were only identified in the matrix of HEA-CrMnFeCoNi. Thermodynamic equilibrium calculations with FactSage (Log(S2) vs. Log(O2), ΔG of reactions) are in good agreement with these observations. The intense diffusion of Cr in the ternary alloy leads to an immediate formation of a protective Cr2O3 layer. The fast diffusion of Mn through the bulk HEA material and through the formed Cr2O3 layer compared to the other alloying elements is considered as the rate-limiting process. T2 - DMG Sektionstreffen Angewandte Mineralogie und Kristallographie CY - Online meeting DA - 25.02.2021 KW - Cr2O3 KW - High-Temperature Corrosion KW - HEA KW - MEA PY - 2021 AN - OPUS4-52164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Current and future technological advancement in polymer matrix composites enabled through fundamental discoveries N2 - This presentation is a summary of the work from the past 20 years’ development of PMC-testing at the BAM-FB 5.3 with respect to safety-relevant design of advanced light weight structures in aircraft, wind turbine and automotive applications. The talk begins with wood as an example from nature, and emphasizes that load case, fiber architectural design and the production process and quality have to go hand in hand to generate an advanced light weight structure. Since PMC-relevant basic findings of mankind span across hundreds of years, high-performance composite applications today are based more on long term experiences than on breakthrough inventions of modern days. In the second part of the talk, future plans and projects of FB-5.3 are presented, specifically addressing H2-safety, circular economy, recycling by design and digitalization of PMC-technologies. T2 - Abteilungsseminar CY - Online meeting DA - 07.09.2021 KW - Polymer Matrix Composites KW - Thermo mechanical fatigue PY - 2021 AN - OPUS4-54150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Botsch, B T1 - Classification of fracture surface types based on SEM images N2 - The following work deals with the quantitative fracture surface evaluation in damage analysis. So far, fracture surfaces have almost exclusively been evaluated qualitatively, i.e. the presence of fracture features is documented and their surface proportions are estimated, if necessary. Many years of experience are required, as well as an intensive comparison with defined comparative images from the literature. The aim of this work is the development of classifiers which can recognize fracture mechanisms or fracture features in scanning electron microscope images (SEM). The basis is 46 SEM images, which have been evaluated by fractography experts with regard to fracture features. The existing data set of images is expanded using augmentation methods in order to increase the variability of the data and counteract overfitting. Only convolutional neural networks (CNN) are used to create the classifiers. Various network configurations are tested, with the SegNet achieving the best results. T2 - Materialsweek 2021 CY - Online meeting DA - 07.09.2021 KW - Fractography KW - Fracture surface KW - Deep learning KW - SEM PY - 2021 AN - OPUS4-53418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jentzsch, Stefan T1 - Numerical and experimental investigations on metal shear band formation at high strain rates with a Hopkinson bar setup N2 - The essence of dynamic failure is closely linked to the formation of adiabatic shear bands (ASB), which result from the localization of shear strain under high deformation speeds accompanied by a rapid temperature increase. Understanding this phenomenon is crucial in view of safety issues when impacts of fast rotating machine components (i.e. aircraft turbine blades) may occur. Our contribution addresses both the experimental evidence and characterization of ASBs due to high-speed impact tests at the Split HOPKINSON pressure bar (SHPB) setup and the finite element analysis to determine the parameters of the underlying constitutive model, which is closely related to JOHNSON-COOK (JC) material model. Experimental investigations were performed on notched shear specimens made of the fine -grained structural steel S690QL and the displacements in the regions affected by shear localization were measured with subset-based local Digital Image Correlation (DIC). The displacement fields, obtained in the SHPB tests, were considered as an objective to validate and to identify the constitutive parameters with. The JC model could reasonably reproduce the displacement distribution. In order to overcome the issues with mesh dependency we provide a nonlocal extension based on the implicit gradient model approach. T2 - GAMM Annual Meeting 2023 CY - Dresden, Germany DA - 30.05.2023 KW - Gradient-enhanced damage KW - Adiabatic shear bands KW - Split Hopkinson bar KW - Digital image correlation KW - Viscoplasticity KW - Finite element analysis PY - 2023 AN - OPUS4-57827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruns, Sebastian T1 - Digitalizing a lab course for undergraduate students: ELN, ontology, data management N2 - We report about a joint project aiming at the digitalization of a lab course in materials testing. The undergraduate students were asked to prepare samples of a precipitation hardened aluminum alloy and characterize them using hardness and tensile tests. In a first step, we developed the frames for the digital labor notebook using eLabFTW. The primary data and the relevant metadata of each run were saved in a central database and made available for analysis and report issues. The whole set of results produced in a course was made available in the database. This database can be improved and serve as an open repository for data on this specific alloy. The logical frame for the joint project was provided by the PMD Core Ontology (PMDco), a mid-level ontology that enables the representation and description of processes and process chains in an MSE-specific manner, ensuring full traceability of generated data. For the digitalization of this lab course, the tensile test ontology (TTO) was applied which is designed as a module of the PMDco using strongly related semantic concepts. T2 - FEMS EUROMAT 2023 CY - Frankfurt a. M., Germany DA - 03.09.2023 KW - Electronic Lab Notebook KW - FAIR data management KW - Digtial Representation KW - Knowledge graph and ontologies PY - 2023 AN - OPUS4-58207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Testing the fibre matrix interface of short glass fibre reinforced PMCs with using the push out technique N2 - With this presentation, the push-out technique is explained. The focus of the experimental work is on the characterization of the fiber-matrix interface of short fiber reinforced composites. The reinforcing component was glass fibers and the matrix polymer was PA6.6 and PPA. It is demonstrated for the first time that the push-out technique ca be applied on injection molded short fiber PMC and is sensitive to the mechanical interface properties. Further studies are planned on the influence of multiple processing, the temperature and humidity. T2 - Composirtes United Workshop „Fiber Matrix Interphases“ CY - Online meeting DA - 09.11.2023 KW - Polymer Matrix Composite KW - Glass Fibres KW - PA6.6 KW - PPA KW - Push-out Test KW - Interface Strength PY - 2023 AN - OPUS4-59053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Wencke T1 - High temperature corrosion phenomena of HEAs and MEAs N2 - High- and medium-entropy alloys (HEAs and MEAs) constitute a new class of materials. Those with a face-centered cubic (fcc) structure from the Cr-Mn-Fe-Co-Ni system have excellent mechanical properties and are considered for high-temperature applications since diffusion in these alloys was reported to be sluggish. However, their corrosion resistance at high temperatures must still be evaluated to further qualify them for such kinds of applications. Various groups studied the oxidation behavior of HEAs and MEAs under (dry) laboratory and artificial air as well as CO2/CO mixtures in different temperature ranges. CrCoNi exhibits the best corrosion resistance at 800 °C due to the formation of a protective Cr2O3 layer. The matrix below the oxide scale was reported to be correspondingly depleted in Cr. It was further shown that the addition of Mn and Fe to CrCoNi changes the phase composition of the oxide scale at 800 °C. A Mn2O3 layer was grown during oxidation on CrMnCoNi and CrMnFeCoNi and a Cr2O3 scale was formed at the matrix/oxide scale interface. Beneath these oxide layers, Mn- and Cr-depleted zones were detected. These phase morphologies demonstrate the inward diffusion of oxygen and outward diffusion of Cr and Mn resulting in the formation of Cr2O3 and Mn2O3. In the present study, the corrosion resistance of CrMnFeCoNi and CrCoNi were confirmed and additionally characterized under further oxidizing atmospheres at 800 °C including Ar-2 Vol.% O2, Ar-2 Vol.% H20, and Ar-2 Vol.% SO2 mixtures. T2 - Symposium on Advanced Mechanical and Microstructural Characterization of High-Entropy Alloys CY - Ruhr-Universität Bochum, Germany DA - 03.02.2020 KW - Mn3O4 KW - High-entropy alloy KW - Medium-entropy alloy KW - High-temperature corrosion KW - Chromia PY - 2020 AN - OPUS4-50984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane T1 - Effect of a mixed atmosphere H2O-O2-SO2 on the oxidation kinetics and phase formation on CrMnFeCoNi and CrCoNi N2 - The high-entropy alloy (HEA) CrMnFeCoNi and the medium-entropy alloy (MEA) CrCoNi with a face-centered cubic (fcc) structure have excellent mechanical properties and are considered for high-temperature applications. Both materials were exposed under several oxidized atmospheres in a wide temperature range/regime. Mn-oxide (Mn3O4, Mn2O3) was mainly formed on the HEA and Cr2O3 on the MEA. The fast diffusion of manganese prevents the formation of a continuous chromia layer on CrMnFeCoNi in Ar-O2, Ar-H2O and Ar-SO2 at 800°C. The Cantor alloy and his ternary subsystem CrCoNi were exposed in Ar-O2-H2O-SO2 at 800°C up to 96 h to clarify their oxidation behavior in a mixed atmosphere. The oxidized samples were analyzed by weight measurement, scanning electron microscopy (SEM), and X-ray diffraction analysis (XRD). It was found that mass gain of all samples increased with increasing exposure time. The oxidation rate of the Cantor alloy is significantly higher than that of the ternary alloy system. T2 - International Conference on High Entropy Materials CY - Berlin, Germany DA - 27.09.2020 KW - High Entropy Alloys KW - Medium Entropy Alloys KW - High temperature corrosion KW - Oxidation KW - Sulfidation PY - 2020 AN - OPUS4-51488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nguyen, Ngoc Tam Thi T1 - Reinventing Piping for Hydrogen Applications – A Composite Approach N2 - A key step towards achieving climate neutrality in the European Union (EU) by 2050 is the transition to renewable energy sources. Green hydrogen plays a central role in this shift but remains costly, particularly through the utilization of PEM electrolysis. Currently, around 50% of the costs associated with electrolyser systems are attributed to system peripherals, underscoring the potential for cost savings through standardization and the use of cost-effective materials [Tja17, IRE20]. In the collaborative project "PolyH2Pipe", the Institute of Plastics Processing in Industry and Craft (IKV), the Welding and Joining Institute (ISF) and BAM Division 5.3 are developing media-carrying pipe systems made of continuous fiber-reinforced thermoplastics (TP-FR) for hydrogen applications. The project aims to design these pipes, develop suitable joining techniques and validate the requirements for these piping systems. This research initiative serves as a foundational basis for the subsequent market introduction of large-scale TP-FR pipe systems for electrolysers and fuel cell systems. Initial test results will be presented as a part of the talk during the colloquium. T2 - H2Safety Colloquium - Materials compatibility and properties CY - Online meeting DA - 14.05.2025 KW - Hydrogen KW - Polymer Matrix Composites KW - Electrolyser KW - Piping PY - 2025 AN - OPUS4-63134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weinel, Kristina T1 - Plasmonic Behavior in Assemblies of Disordered Gold Nanoparticles N2 - Plasmons are collective oscillations of the free electron density in metals which can be described by an electromagnetic field. Surface plasmons are longitudinal waves propagating at the surface of the metallic material coupled to an external field. Localized surface plasmons on a nanoparticle reveal the behavior of standing waves with discrete resonance frequencies whose dominating mode is called dipole mode. Coupling of nanoparticles leads eventually to a hybridization of those dipole modes and therefore to spectral and spatial delocalization which was already investigated in ordered systems. In disordered systems, there are a lot of open questions regarding the propagation behavior which changes from delocalization to localization for instance due to the disorder. This phenomenon is then called Anderson localization. To investigate the propagation behavior of plasmonic waves in an assembly of disordered gold NPs, we combine experimental results of electron energy loss spectroscopy in a scanning transmission microscope with simulation results of the self-consistent dipole modelling. We indeed find experimentally localization of plasmon modes and with the simulation we could exclude other localization mechanism such as life-time damping or retardation. In conclusion, we could found Anderson localization of surface plasmons in assemblies of disordered gold nanoparticles which will enhance the understanding of this kind of vector waves to the Anderson localization as a general wave behavior in disordered systems. T2 - PhD seminar Leipniz Institut for solid state and material research (IFW Dresden) CY - Dresden, Germany DA - 19.06.2024 KW - Plasmonic KW - EELS in STEM KW - Self-consistent dipole model KW - Assemblies of gold nanoparticles PY - 2024 AN - OPUS4-60945 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Luminescent multifunctional nanostructures for sensing and theranostics applications N2 - An overview of the work carried out at LEMAF - Laboratory of Spectroscopy of Functional Materials at IFSC/USP was given. The work presented focus on the design, production and functional characterization of multifunctional nanoparticles. T2 - NANOANDES - Latin American School on Nanomaterials and Appllications CY - Araraquara, SP, Brazil DA - 10.10.2023 KW - Multifunctional nanoparticles KW - Upconversion nanoparticles KW - Quantum dots KW - Noble metal nanoparticles PY - 2023 AN - OPUS4-60363 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker T1 - Advanced lightweight applications – recycling versus reliability and fossil energy footprint N2 - Advanced light weight applications like aircrafts and wind turbine blades are made of fibre reinforced plastics (FRP) with continuous fibre reinforcement and must withstand a high thermo-mechanical cyclic loading. The quality of the fibre matrix interface has a high impact on the fatigue life and was continuously improved over the years since the 50th. The fatigue life of glass fibre reinforced plastics (GFRP) used in aircraft industry is 10 to 100 times higher compared to glass fibre non crimp fabrics used for wind turbine blades. To assure a constant and reliable high quality and strength of reinforcement fibres, synthetic fibre production is state of the art (CF, GF). There is a need for recycling GFRP and CFRP waste due to the upcoming use. Pyrolysis and solvolysis are more expensive than the mechanical route however enable a more sustainable recycling. Natural fibres and recycled synthetic fibres have a high scatter in quality and strength. Hence it is a challenge to optimize the production / recycling processes to get a reliable quality for any demanding (second life) application. Chemical routes for using renewables resources and recycling, is going to be a good approach especially for polymer-matrix systems to get 100% quality (back) compared to the state of the art. Finally, a proper design, life-time extension and repair is preferable to recycling to keep the carbon footprint as low as possible. T2 - 27. INTERNATIONALES DRESDNER LEICHTBAUSYMPOSIUM CY - Dresden, Germany DA - 13.06.2024 KW - Polymer Matrix Composites KW - Carbon Fibre KW - Recycling KW - Circular Economy PY - 2024 UR - https://leichtbausymposium.de/deu/ AN - OPUS4-60683 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Camargo, Andrea Simone Stucchi T1 - Luminescent multifunctional nanostructures for sensing and theranostics applications N2 - The research carried out at the Laboratory of Spectroscopy of Functional Materials at IFSC/USP, in Brazil, is focused on the synthesis and structural-property correlation of luminescent materials including rare-earth (RE) doped glasses, ceramics and hybrid host-guest materials. For the past five years, we have been particularly interested in the development of single- and multifunctional nanosystems based on core-shell upconversion nanoparticles (UCNP) associated with dyes, organometallic complexes and other organic molecules, for biophotonic and sensing applications. In these systems, we take advantage of energy transfer between the UCNPs and the molecules to either supress or enhance luminescent response. Examples include the possibility of bioimaging and photodynamic therapy of bacteria and cancer cells, simultaneous magnetothermia and thermometry, localized O2 sensing, fast detection and quantification of biological markers (e.g. kidney disease) and microorganisms. On what concerns the development of luminescent sensors - a recently started project, our aim is to develop paper-based platforms for point-of-care devices. In this presentation, an overview of our contributions for the past years and our future aims will be presented with several examples. T2 - ICL2023 - 20th International Conference on Luminescence CY - Paris, France DA - 27.08.2023 KW - Upconversion KW - Sensing KW - Theranostics KW - Nanoparticles KW - Photodynamic therapy PY - 2023 AN - OPUS4-60362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - Elastic Microstructures in Metallic Glasses N2 - Metallic glasses (MGs) are disordered solids that exhibit a range of outstanding mechanical, thermomechanical, and functional properties. Whilst being a promising class of structural materials, well-defined and exploitable structure-property relationships are still lacking. This offsets them strongly from the crystalline counterparts, for which length-scale based property determination has been key for decades. In recent years, both atomistic simulations and experiments have nurtured the view of heterogeneities that manifest themselves either as a structural partitioning into well-relaxed percolated network components and more frustrated domains in atomistic simulations, or as spatially-resolved property fluctuations revealed with atomic force microscopy. These signatures depend sensitively on the processing history and likely reflect emerging medium-range order fluctuations at the scale of 1-10 nanometers. Here we demonstrate and discuss the emergence of spatially resolved property fluctuations at length scales that are one to two orders of magnitude larger. Such long-range decorrelation length scales are hard to reconcile in a monolithic glass but may offer the perspective of experimentally easy-to-access length-scale based structure-property relationships. Whilst long-range property fluctuations can be seen in both the plastic and elastic response, we focus here on high-throughput elastic nanoindentation mapping across the surface of a Zr-based model glass. After a deconvolution of surface topography and curvature effects, the spatially-resolved elastic response reveals an elastic microstructure with a correlation length of ca. 150-170 nm. Analytical scanning-transmission electron microscopy (STEM) is used to link the elastic property fluctuations to the chemistry and structure of the MG. In concert, nano-elastic mapping and STEM suggests that structural variations in the glass are responsible for the unexpectedly large length scales. We discuss these findings in terms of the materials processing history and the perspective of exploiting nanoindentation-based spatial mapping to uncover structural length scales in atomically disordered solids. T2 - 7th International Indentation Workshop – IIW7 CY - Hyderabad, India DA - 17.12.2023 KW - Metallic glass KW - Nanoindentation KW - Microstructure PY - 2023 AN - OPUS4-60692 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 -