TY - JOUR A1 - Li, L. A1 - Darvishi Kamachali, Reza A1 - Li, Z. A1 - Zhang, Z. T1 - Grain boundary energy effect on grain boundary segregation in an equiatomic high-entropy alloy N2 - Grain boundary (GB) Segregation has a substantial effect on the microstructure evolution and properties of polycrystalline alloys. The mechanism of nanoscale segregation at the various GBs in multicomponent alloys is of great challenge to reveal and remains elusive so far. To address this issue, we studied the GB segregation in a representative equiatomic FeMnNiCoCr high-entropy alloy (HEA) aged at 450 °C. By combining transmission Kikuchi diffraction, atom probe tomography analysis and a density-based thermodynamics modeling, we uncover the nanoscale segregation behavior at a series of well-characterized GBs of different characters. No segregation occurs at coherent twin boundaries; only slight nanoscale segregation of Ni takes place at the low-angle GBs and vicinal \Sigma 29b coincidence site lattice GBs. Ni and Mn show cosegregation of high levels at the general high-angle GBs with a strong depletion in Fe, Cr, and Co. Our density-based thermodynamic model reveals that the highly negative energy of mixing Ni and Mn is the main driving force for nanoscale cosegregation to the GBs. This is further assisted by the opposite segregation of Ni and Cr atoms with a positive enthalpy of mixing. It is also found that GBs of higher interfacial energy, possessing lower atomic densities (higher disorder and free volume), show higher segregation levels. By clarifying the origins of GB segregations in the FeMnNiCoCr HEA, the current work provides fundamental ideas on nanoscale segregation at crystal defects in multicomponent alloys. KW - Thermodynamics KW - High-Entropy Alloys KW - Grain Boundary Segregation PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508827 DO - https://doi.org/10.1103/PhysRevMaterials.4.053603 VL - 4 IS - 5 SP - 053603 PB - American Physical Society AN - OPUS4-50882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhou, X. A1 - Wei, Y. A1 - Kühbach, M. A1 - Zhao, H. A1 - Vogel, F. A1 - Darvishi Kamachali, Reza A1 - Thompson, G. B. A1 - Raabe, D. A1 - Gault, B. T1 - Revealing in-plane grain boundary composition features through machine learning from atom probe tomography data N2 - Grain boundaries (GBs) are planar lattice defects that govern the properties of many types of polycrystalline materials. Hence, their structures have been investigated in great detail. However, much less is known about their chemical features, owing to the experimental difficulties to probe these features at the atomic length scale inside bulk material specimens. Atom probe tomography (APT) is a tool capable of accomplishing this task, with an ability to quantify chemical characteristics at near-atomic scale. Using APT data sets, we present here a machine-learning-based approach for the automated quantification of chemical features of GBs. We trained a convolutional neural network (CNN) using twenty thousand synthesized images of grain interiors, GBs, or triple junctions. Such a trained CNN automatically detects the locations of GBs from APT data. Those GBs are then subjected to compositional mapping and analysis, including revealing their in-plane chemical decoration patterns. We applied this approach to experimentally obtained APT data sets pertaining to three case studies, namely, Ni-P, Pt-Au, and Al-Zn-Mg-Cu alloys. In the first case, we extracted GB specific segregation features as a function of misorientation and coincidence site lattice character. Secondly, we revealed interfacial excesses and in-plane chemical features that could not have been found by standard compositional analyses. Lastly, we tracked the temporal evolution of chemical decoration from early-stage solute GB segregation in the dilute limit to interfacial phase separation, characterized by the evolution of complex composition patterns. This machine-learning-based approach provides quantitative, unbiased, and automated access to GB chemical analyses, serving as an enabling tool for new discoveries related to interface thermodynamics, kinetics, and the associated chemistry-structure-property relations. KW - Machine learning KW - Digitalization KW - Alloy microstructure PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543049 DO - https://doi.org/10.1016/j.actamat.2022.117633 SN - 1359-6454 VL - 226 SP - 1 EP - 15 PB - Elsevier CY - Amsterdam AN - OPUS4-54304 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lin, Y.-Y. A1 - Schleifer, F. A1 - Holzinger, M. A1 - Ta, N. A1 - Skrotzki, Birgit A1 - Darvishi Kamachali, Reza A1 - Glatzel, U. A1 - Fleck, M. T1 - Quantitative Shape-Classification of Misfitting Precipitates during Cubic to Tetragonal Transformations: Phase-Field Simulations and Experiments N2 - The effectiveness of the mechanism of precipitation strengthening in metallic alloys depends on the shapes of the precipitates. Two different material systems are considered: tetragonal γ′′ precipitates in Ni-based alloys and tetragonal θ′ precipitates in Al-Cu-alloys. The shape formation and evolution of the tetragonally misfitting precipitates was investigated by means of experiments and phase-field simulations. We employed the method of invariant moments for the consistent shape quantification of precipitates obtained from the simulation as well as those obtained from the experiment. Two well-defined shape-quantities are proposed: (i) a generalized measure for the particles aspect ratio and (ii) the normalized λ2, as a measure for shape deviations from an ideal ellipse of the given aspect ratio. Considering the size dependence of the aspect ratio of γ′′ precipitates, we find good agreement between the simulation results and the experiment. Further, the precipitates’ in-plane shape is defined as the central 2D cut through the 3D particle in a plane normal to the tetragonal c-axes of the precipitate. The experimentally observed in-plane shapes of γ′′-precipitates can be quantitatively reproduced by the phase-field model. KW - γ″ phase KW - Phase-field simulation KW - Misfitting precipitate KW - Nickel-base alloy KW - Al-Cu alloy KW - θ′ phase KW - Precipitate shape PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522743 DO - https://doi.org/10.3390/ma14061373 VL - 14 IS - 6 SP - 1373 PB - MDPI AN - OPUS4-52274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darvishi Kamachali, Reza A1 - da Silva, A. A1 - McEniry, E. A1 - Gault, B. A1 - Neugebauer, J. A1 - Raabe, D. T1 - Segregation-assisted spinodal and transient spinodal phase separation at grain boundaries N2 - Segregation to grain boundaries affects their cohesion, corrosion, and embrittlement and plays a critical role in heterogeneous nucleation. In order to quantitatively study segregation and low-dimensional phase separation at grain boundaries, here, we apply a density-based phase-field model. The current model describes the grain-boundary thermodynamic properties based on available bulk thermodynamic data, while the grain-boundary-density profile is obtained using atomistic simulations. To benchmark the performance of the model, Mn grain-boundary segregation in the Fe–Mn system is studied. 3D simulation results are compared against atom probe tomography measurements conducted for three alloy compositions. We show that a continuous increase in the alloy composition results in a discontinuous jump in the segregation isotherm. The jump corresponds to a spinodal Phase separation at grain boundary. For alloy compositions above the jump, we reveal an interfacial transient spinodal phase separation. The transient spinodal phenomenon opens opportunities for knowledge-based microstructure design through the chemical manipulation of grain boundaries. The proposed density-based model provides a powerful tool to study thermodynamics and kinetics of segregation and phase changes at grain boundaries. KW - Grain Boundary Spinodal KW - Densty-based Thermodynamics KW - Microstrucrue Design PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519497 DO - https://doi.org/10.1038/s41524-020-00456-7 VL - 6 IS - 1 SP - 191 PB - Nature AN - OPUS4-51949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ta, N. A1 - Bilal, M. U. A1 - Häusler, I. A1 - Saxena, A. A1 - Lin, Y.-Y. A1 - Schleifer, F. A1 - Fleck, M. A1 - Glatzel, U. A1 - Skrotzki, Birgit A1 - Darvishi Kamachali, Reza T1 - Simulation of the θ′ Precipitation Process with Interfacial Anisotropy Effects in Al-Cu Alloys N2 - The effects of anisotropic interfacial properties and heterogeneous elasticity on the growth and ripening of plate-like θ′-phase (Al2Cu) in Al-1.69 at.% Cu alloy are studied. Multi-phase-field simulations are conducted and discussed in comparison with aging experiments. The precipitate/matrix interface is considered to be anisotropic in terms of its energy and mobility. We find that the additional incorporation of an anisotropic interfacial mobility in conjunction with the elastic anisotropy result in substantially larger aspect ratios of the precipitates closer to the experimental observations. The anisotropy of the interfacial energy shows comparably small effect on the precipitate’s aspect ratio but changes the interface’s shape at the rim. The effect of the chemo-mechanical coupling, i.e., the composition dependence of the elastic constants, is studied as well. We show that the inverse ripening phenomenon, recently evidenced for δ’ precipitates in Al-Li alloys (Park et al. Sci. Rep. 2019, 9, 3981), does not establish for the θ′ precipitates. This is because of the anisotropic stress fields built around the θ′ precipitates, stemming from the precipitate’s shape and the interaction among different variants of the θ′ precipitate, that disturb the chemo-mechanical effects. These results show that the chemo-mechanical effects on the precipitation ripening strongly depend on the degree of sphericity and elastic isotropy of the precipitate and matrix phases. KW - Aging KW - Phase-field simulation KW - Interfacial anisotropy KW - Chemo-mechanical coupling KW - Precipitation KW - Elasticity KW - θ′-(Al2Cu) precipitate phase PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522672 DO - https://doi.org/10.3390/ma14051280 VL - 14 IS - 5 SP - 1280 PB - MDPI AN - OPUS4-52267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, Lei A1 - Darvishi Kamachali, Reza T1 - Density-based grain boundary phase diagrams: Application to Fe-Mn-Cr, Fe-Mn-Ni, Fe-Mn-Co, Fe-Cr-Ni and Fe-Cr-Co alloy systems N2 - Phase diagrams are the roadmaps for designing bulk phases. Similar to bulk, grain boundaries can possess various phases, but their phase diagrams remain largely unknown. Using a recently introduced density-based model, here we devise a strategy for computing multi-component grain boundary phase diagrams based on available bulk (CALPHAD) thermodynamic data. Fe-Mn-Cr, Fe-Mn-Ni, Fe-Mn-Co, Fe-Cr-Ni and Fe-Cr-Co alloy systems, as important ternary bases for several trending steels and high-entropy alloys, are studied. We found that despite its solute segregation enrichment, a grain boundary can have lower solubility limit than its corresponding bulk, promoting an interfacial chemical decomposition upon solute segregation. This is revealed here for the Fe-Mn-base alloy systems. The origins of this counter-intuitive feature are traced back to two effects, i.e., the magnetic ordering effect and the low cohesive energy of Mn solute element. Different aspects of interfacial phase stability and GB co-segregation in ternary alloys are investigated as well. We show that the concentration gradient energy contributions reduce segregation level but increase grain boundary solubility limit, stabilizing the GB against a chemical decomposition. Density-based grain boundary phase diagrams offer guidelines for systematic investigation of interfacial phase changes with applications to microstructure defects engineering. KW - Densty-based Thermodynamics KW - Microstrucrue Design KW - Grain Boundary Phase Diagram PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522207 DO - https://doi.org/10.1016/j.actamat.2021.116668 SN - 1359-6454 VL - 207 SP - 116668 PB - Elsevier Ltd. AN - OPUS4-52220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rockenhäuser, Christian A1 - Rowolt, C. A1 - Milkereit, B. A1 - Darvishi Kamachali, Reza A1 - Kessler, O. A1 - Skrotzki, Birgit T1 - On the long-term aging of S-phase in aluminum alloy 2618A N2 - The aluminum alloy 2618A is applied for engine components such as radial compressor wheels which operate for long time at elevated temperatures. This results in coarsening of the hardening precipitates and degradation in mechanical properties during the long-term operation, which is not taken into account in the current lifetime prediction models due to the lack of quantitative microstructural and mechanical data. To address this issue, a quantitative investigation on the evolution of precipitates during long-term aging at 190 °C for up to 25,000 h was conducted. Detailed transmission electron microscopy (TEM) was combined with Brinell hardness measurements and thorough differential scanning calorimetry (DSC) experiments. The results showthat GPB zones and S-phase Al2CuMg grow up to < 1,000 h during which the GPB zones dissolve and S-phase precipitates form. For longer aging times, only S-phase precipitates coarsen, which can be well described using the Lifshitz–Slyozov Wagner theory of ripening. A thorough understanding of the underlying microstructural processes is a prerequisite to enable the integration of aging behavior into the established lifetime models for components manufactured from alloy 2618A. KW - Long-term aging KW - Transmission electron microscopy (TEM) KW - Differential scanning calorimetry (DSC) KW - Microstructure KW - S-phase KW - Ostwald ripening PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519899 DO - https://doi.org/10.1007/s10853-020-05740-x SN - 0022-2461 VL - 56 IS - 14 SP - 8704 EP - 8716 PB - Springer Nature AN - OPUS4-51989 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bayerlein, Bernd A1 - Hanke, T. A1 - Muth, Thilo A1 - Riedel, Jens A1 - Schilling, Markus A1 - Schweizer, C. A1 - Skrotzki, Birgit A1 - Todor, A. A1 - Moreno Torres, Benjami A1 - Unger, Jörg F. A1 - Völker, Christoph A1 - Olbricht, Jürgen T1 - A Perspective on Digital Knowledge Representation in Materials Science and Engineering N2 - The amount of data generated worldwide is constantly increasing. These data come from a wide variety of sources and systems, are processed differently, have a multitude of formats, and are stored in an untraceable and unstructured manner, predominantly in natural language in data silos. This problem can be equally applied to the heterogeneous research data from materials science and engineering. In this domain, ways and solutions are increasingly being generated to smartly link material data together with their contextual information in a uniform and well-structured manner on platforms, thus making them discoverable, retrievable, and reusable for research and industry. Ontologies play a key role in this context. They enable the sustainable representation of expert knowledge and the semantically structured filling of databases with computer-processable data triples. In this perspective article, we present the project initiative Materials-open-Laboratory (Mat-o-Lab) that aims to provide a collaborative environment for domain experts to digitize their research results and processes and make them fit for data-driven materials research and development. The overarching challenge is to generate connection points to further link data from other domains to harness the promised potential of big materials data and harvest new knowledge. KW - Data infrastructures KW - Digital representations KW - Digital workflows KW - Knowledge graphs KW - Materials informatics KW - Ontologies KW - Vocabulary providers PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546729 DO - https://doi.org/10.1002/adem.202101176 SN - 1438-1656 SP - 1 EP - 14 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-54672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schilling, Markus A1 - Marschall, Niklas A1 - Niebergall, Ute A1 - Böhning, Martin T1 - Dataset of comprehensive Full-notch creep tests (FNCT) of selected high-density polyethylene (PE-HD) materials N2 - The dataset provided in this repository comprises data obtained from a series of full-notch creep tests (FNCT) performed on selected high-density polyethylene (PE-HD) materials (for further details, see section 1 Materials in this document) in accordance with the corresponding standard ISO 16770. The FNCT is one of the mechanical testing procedures used to characterize polymer materials with respect to their environmental stress cracking (ESC) behavior. It is widely applied for PE-HD materials, that are predominantly used for pipe and container applications. It is based on the determination of the time to failure for a test specimen under constant mechanical load in a well-defined and temperature controlled liquid environment. The test device used here also allows for continuous monitoring of applied force, specimen elongation and temperature. KW - Polyethylene KW - Environmental Stress Cracking KW - Full-notch creep test KW - PE-HD KW - Crack growth PY - 2023 DO - https://doi.org/10.5281/zenodo.10143351 PB - Zenodo CY - Geneva AN - OPUS4-58835 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd A1 - Zia, Ghezal Ahmad A1 - Schilling, Markus A1 - Waitelonis, J. A1 - v. Hartrott, P. A1 - Hanke, T. A1 - Skrotzki, Birgit T1 - Towards interoperability: Digital representation of a material specific characterization method N2 - Certain metallic materials gain better mechanical properties through controlled heat treatments. In age-hardenable aluminum alloys, the strengthening mechanism is based on the controlled formation of nanometer sized precipitates, which hinder dislocation movement. Analysis of the microstructure and especially the precipitates by transmission electron microscopy allows identification of precipitate types and orientations. Dark-field imaging is often used to image the precipitates and quantify their relevant dimensions. The present work aims at the digital representation of this material-specific characterization method. Instead of a time-consuming, manual image analysis, a digital approach is demonstrated. The integration of an exemplary digital workflow for quantitative precipitation analysis into a data pipeline concept is presented. Here ontologies enable linking of contextual information to the resulting output data in a triplestore. Publishing digital workflow and ontologies ensures the reproducibility of the data. The semantic structure enables data sharing and reuse for other applications and purposes, demonstrating interoperability. T2 - TMS - 7th World Congress on Integrated Computational Materials Engineering (ICME) CY - Orlando, Florida, USA DA - 21.05.2023 KW - Ontology KW - Semantic Interoperability KW - Digtial Representation KW - Data Management KW - Reproducibility KW - FAIR PY - 2023 AN - OPUS4-57548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus A1 - Bayerlein, Bernd A1 - v. Hartrott, P. A1 - Waitelonis, J. A1 - Birkholz, H. A1 - Grundmann, J. A1 - Portella, Pedro Dolabella A1 - Skrotzki, Birgit T1 - FAIR data in PMD: Development of MSE mid-level and standard-compliant application ontologies N2 - The efforts taken within the project ‘platform MaterialDigital’ (PMD, materialdigital.de) to store FAIR data in accordance with a standard-compliant ontological representation (‘application ontology’) of a tensile test of metals at room temperature (ISO 6892-1:2019-11) will be presented. This includes the path from developing an ontology in accordance with the respective standard, converting ordinary data obtained from standard tests into the interoperable RDF format, up to connecting the ontology and data. The semantic connection of the ontology and data leads to interoperability and an enhanced ability of querying. For further reusability of data and knowledge semantically stored, the PMD core ontology (PMDco) was developed, which is a mid-level ontology in the field of MSE. The semantic connection of the tensile test application ontology to the PMDco is also presented. Moreover, Ontopanel, a tool for domain experts facilitating visual ontology development and mapping for FAIR data sharing in MSE, is introduced briefly. T2 - World Congress on Integrated Computational Materials and Engineering (ICME) CY - Orlando, Florida, USA DA - 21.05.2023 KW - Digitalization KW - Semantic Web Technologies KW - FAIR KW - Data Interoperability KW - PMD Core Ontology KW - Tensile Test Ontology PY - 2023 AN - OPUS4-57549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus A1 - Bayerlein, Bernd A1 - Waitelonis, J. 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 - Schilling, Markus T1 - Plattform MaterialDigital in DIN NA 062-01-42 AA N2 - In dieser Präsentation werden die letzten Entwicklungen in der Plattform MaterialDigital (PMD) im DIN Normenausschuss 062-01-42 AA zur Zug- und Duktilitätsprüfung für Metalle vorgestellt. Dabei werden hauptsächlich die Entwicklungen und Neustrukturierung der PMD Core Ontology (PMDco) sowie die entsprechende Anpassung der Zugversuchsontologie (Tensile Test Ontology - TTO) inklusive des Datenmappings adressiert. Für das Datenmapping wurde ein speziell im Zusammenhang mit der PMD erstellter Zugversuchsdatensatz verwendet, welcher frei verfügbar in einem online Zenodo Repository veröffentlicht ist. Weiterhin wird die Weiterentwicklung der Norm in Verbindung mit ihrer folgenden Revision hinsichtlich der Integration von Aspekten zur Digitalisierung in der Materialwissenschaft und Werkstofftechnik sowie der Verwendung von semantischen Technologien, wie unter anderem ontologischen Repräsentationen von Materialien und Prozessen, diskutiert. T2 - DIN NA 062-01-42 AA Meeting CY - Berlin, Germany DA - 14.06.2023 KW - Ontologie KW - Semantic Web Technologies KW - Normung KW - DIN KW - Plattform MaterialDigital KW - Zugversuch KW - Tensile Test KW - Materialcharakterisierung PY - 2023 AN - OPUS4-57803 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Zapala, P. A1 - Abel, Andreas A1 - Michels, H. A1 - Skrotzki, Birgit T1 - Werkstoffanwendungen für Eisenaluminide (FeAl), (WAFEAL) N2 - Die zunehmende geopolitische Bedeutung der Ressourcenverfügbarkeit sowie die Anforderungen an einen geschlossenen Materialkreislauf treiben die Materialforschung voran, um konventionelle Werkstoffe mit weniger kritischen Zusätzen zu legieren oder sogar vollständig mit nachhaltigeren Alternativen zu substituieren. Eine potenzielle Alternative stellen die intermetallischen Eisenaluminid-Legierungen (FeAl) dar. Im Labormaßstab wurden bereits viele Legierungskonzepte für verbesserte Hochtempera- tureigenschaften oder Duktilität erfolgreich gießtechnisch umgesetzt. Eine erfolgreiche Erprobung von FeAl-Legierungen im industriellen Maßstab stand zu Beginn des Projekts aber weiterhin aus. Ziel des Vorhabens war daher die Entwicklung von simulationsgestützten Gießkonzepten in industrienahe Gießprozesse anhand der Modelllegierung Fe-26Al-4Mo-0,5Ti-1B und die Eingrenzung der prozesstechnischen Verfahrensgrenzen durch Warmrissversuche. Erkenntnisse hieraus wurden in einen praxisorientierten, für zukünftige Anwender in KMUs zugänglichen Handlungskatalog für die gießgerechte Auslegung von Bauteilen aus Eisenaluminiden überführt. Fokus wurde insbesondere auf das Feinguss- und Kokillengussverfahren im Schleuderguss gesetzt. Neben zahlreicher Konstruktions- und Gießprozessparameter wurden auch Wärmebehandlungen und Legierungszusätze (Al, Mo, B) variiert, um den Einfluss von Legierungselementen auf Gießbarkeit, Mikrostruktur und mechanische Kennwerte zu be- stimmen. Eine umfangreiche Basis an Daten aus Mikrostrukturanalysen (Mikroskopische Bildgebung, Bestimmung von Korngrößen sowie Phasenzusammensetzungen und -anteilen, Fraktographie), mechanischen Tests (Härtemessungen, Druckversuch, Zugversuch, Warmzugversuch, Kriechversuch) sowie Messungen thermophysikalischer Eigenschaften konnte für die Modelllegierung erzeugt werden. Korrelationen dieser Informationen mit Prozessvariablen erlaubten Schlussfolgerungen zu Härtungsmechanismen und Duktilität in der Legierung und wie sie prozesstechnisch in Gieß- und Bauteilauslegung gesteuert werden können. Der erfolgreiche Abguss von hochkomplexen Bauteilgeometrien mit dünnen Wandstärken sowie optimierte Legierungszusammensetzungen zeigen Perspektiven auf neue Anwendungsfelder auf. Das Ziel des Forschungsvorhabens ist erreicht worden. KW - Simulationsgestützte Gießkonzepte KW - Intermetallische FeAl-Legierungen PY - 2023 IS - 1322 SP - 1 EP - 168 PB - Forschungsvereinigung Verbrennungskraftmaschinen (FVV) CY - Frankfurt am Main AN - OPUS4-56932 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gesell, Stephan A1 - Fedelich, Bernard A1 - Ganesh, Rahul A1 - Kuna, Meinhard A1 - Skrotzki, Birgit A1 - Kiefer, Björn T1 - A CTOD-based crack growth law for thermomechanical fatigue N2 - Due to combined cyclic mechanical and thermal loading during operation, the material of exhaust gas conducting components of combustion engines is exposed to thermomechanical fatigue (TMF). This leads to formation and growth of cracks, especially at the most highly stressed points of these components. In order to better predict the service life of cracked components before failure, it is necessary to identify a crack propagation law for the material used. Isothermal crack propagation tests have been carried out at several temperatures with a typical cast iron to identify such a law. The crack length is measured by the potential drop method. The compliance method, fractography and thermographic camera measurements have been used to validate and calibrate the potential drop measurements. Each of the isothermal tests has been simulated using a specially developed FEM-algorithm based on remeshing and remapping. This algorithm has been implemented in python and ABAQUS. Thereby, the crack tip region is modeled by collapsed Quad8 elements. From the individual simulations, the cyclic crack tip opening displacement (ΔCTOD) is extracted and regarded as a potential fracture mechanics parameter which controls the crack growth rate. By combining the data from the experiments and the simulations, the crack propagation law has been identified. Finally, anisothermal crack propagation tests have been performed for validation of the crack growth law. T2 - European Conference on Fracture 2022 CY - Funchal, Portugal DA - 27.06.2022 KW - Fatigue crack growth KW - Finite elmenet simulation KW - TMF experiments PY - 2022 AN - OPUS4-56934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus A1 - Marschall, Niklas A1 - Bayerlein, Bernd A1 - Chen, Yue A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit A1 - von Hartrott, P. A1 - Portella, Pedro Dolabella A1 - Waitelonis, J. A1 - Birkholz, H. A1 - Grundmann, J. ED - Zimmermann, M. T1 - Zugversuchsdaten FAIR integriert: Von einer normenkonformen Ontologie bis zu interoperablen Daten im Triple Store N2 - Das hochaktuelle Thema der Integration und Wiederverwendung von Wissen und Daten aus Herstellung, Bearbeitung und Charakterisierung von Materialien ('Digitalisierung von Materialien') wird in den Projekten Innovationsplattform MaterialDigital (PMD, materialdigital.de) und Materials-open-Lab (Mat-o-Lab, matolab.org) adressiert. In diesem Beitrag werden die Weiterentwicklungen in diesen Projekten hinsichtlich der Speicherung von Zugversuchsdaten gemäß einer normenkonformen (DIN EN ISO 6892-1:2019-11) ontologischen Repräsentation vorgestellt. Das umfasst den Weg von der Entwicklung einer Ontologie nach Norm, der Konvertierung von Daten aus Standardtests in das interoperable RDF-Format bis hin zur Verknüpfung von Ontologie und Daten. Letztendlich können die entsprechenden Daten in einem Triple Store abgelegt und abgefragt werden. T2 - Werkstoffprüfung 2022 CY - Dresden, Germany DA - 27.10.2022 KW - Ontology KW - Semantic Web KW - Digitalization KW - Knowledge Representation KW - Tensile Test PY - 2022 UR - https://dgm.de/fileadmin/DGM/Veranstaltungen/2022/Werkstoffpruefung/Tagungsband/WP2022-Tagungsband-online.pdf SN - 978-3-88355-430-3 SP - 105 EP - 110 PB - DGM - Deutsche Gesellschaft für Materialkunde e.V CY - Sankt Augustin AN - OPUS4-56836 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Radners, J. A1 - Han, Ying A1 - von Hartrott, P. A1 - Skrotzki, Birgit T1 - Aluminium Hochtemperaturermüdung N2 - Die hohen Betriebstemperaturen während des Einsatzes von Radialverdichterrädern in Abgasturboladern führen zu einer Änderung der ursprünglich eingestellten Mikrostruktur in der warmfesten Aluminiumlegierung EN AW-2618A (Überalterung). Grund dafür sind thermische Belastungen, die nahe der Aushärtetemperatur liegen und diese kurzzeitig sogar überschreiten können. Die Alterungsmechanismen wurden zusammen mit den Themen niederzyklische (LCF) und thermomechanische Ermüdung (TMF) sowie Kriechen bis max. 190 °C in vorangegangenen Forschungsvorhaben untersucht. Kaum untersucht war bisher das Verhalten der Legierung unter hochzyklischer Beanspruchung (HCF) sowie der Einfluss von Kerben und Lastkollektiven. Da zukünftig mit weiter steigenden Betriebstemperaturen für Radialverdichter zu rechnen ist, wurde in diesem Forschungsvorhaben das HCF-Verhalten bei 230 °C untersucht und somit bei einer Prüftemperatur, die deutlich oberhalb der Aushärtetemperatur liegt. Das Ziel des Projektes war der Aufbau einer geeigneten experimentellen Datenbasis, das Verständnis der relevanten mikrostrukturellen Prozesse sowie die Weiterentwicklung und Anpassung geeigneter Modelle und Bewertungsmethoden. Das experimentelle Untersuchungsprogramm umfasste neben einer Basischarakterisierung des HCF-Verhaltens am Ausgangszustand T61 gezielte mechanische Versuche zur Isolierung der Einflussfakto-ren Mittelspannung (𝑅 = −1, 𝑅 = 0,1), Werkstoffüberalterung (T61, 10 h/230 °C, 1000 h/230 °C), Prüftemperatur (20 °C, 230 °C), Prüffrequenz (0,2 Hz, 20 Hz) sowie Kerbwirkung und variable Amplituden. Darauf aufbauend wurden die in den vorangegangenen Projekten entwickelten Modelle und Bewertungsmethoden angepasst und weiterentwickelt, um die genannten thermischen und mechanischen Belastungen in der Lebensdauerbewertung abzubilden. KW - HCF KW - Aluminium KW - EN AW-2618A KW - Ermüdung PY - 2023 SP - 1 EP - 111 CY - Frankfurt am Main AN - OPUS4-57850 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis Alexander A1 - Hammerschmidt, T. A1 - Gedsun, A. A1 - Forti, M. A1 - Olbricht, Jürgen A1 - Stotzka, R. A1 - Skrotzki, Birgit A1 - Shakeel, Y. A1 - Hunke, S. A1 - Tsybenko, H. A1 - Aversa, R. A1 - Chmielowski, M. A1 - Hickel, T. T1 - IUC02 Framework for Curation and Distribution of Reference Datasets using Creep Data of Ni-Base Superalloys as an Example N2 - In our current view, reference datasets in the MSE domain represent specific material properties, e.g., structural, mechanical, … characteristics. A reference dataset must fulfill high-quality standards, not only in precision of measurement but also in a comprehensive documentation of material, processing, and testing history (metadata). This Infrastructure Use Case (IUC) aims to develop a framework for generating reference material datasets using creep data of a single crystal Ni-based superalloy as a best practice example. In a community-driven process, we aim to encourage the discussion and establish a framework for the creation and distribution of reference material datasets. In this poster presentation, we highlight our current vision and activities and intend to stimulate the discussion about the topic reference datasets and future collaborations and work. T2 - NFDI-MatWerk Conference CY - Siegburg, Germany DA - 27.06.2023 KW - Referenzdaten KW - Reference data KW - Syngle Crystal alloy KW - Creep KW - Metadata schema PY - 2023 AN - OPUS4-57923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis Alexander A1 - Hammerschmidt, T. A1 - Stotzka, R. A1 - Forti, M. A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit A1 - Lenze, A. A1 - Gedsun, A. A1 - Hickel, Tilmann A1 - Tsybenko, H. A1 - Chmielowski, M. A1 - Hunke, S. A1 - Shakeel, Y. T1 - Demonstration of the Infrastructure Use Case 02: Framework for curation and distribution of reference datasets N2 - In our current view, reference datasets in the MSE domain represent specific material properties, e.g., structural, mechanical, … characteristics. A reference dataset must fulfill high-quality standards, not only in precision of measurement but also in a comprehensive documentation of material, processing, and testing history (metadata). This Infrastructure Use Case (IUC) aims to develop a framework for generating reference material datasets using creep data of a single crystal Ni-based superalloy as a best practice example. In a community-driven process, we aim to encourage the discussion and establish a framework for the creation and distribution of reference material datasets. In this poster presentation, we highlight our current vision and activities and intend to stimulate the discussion about the topic reference datasets and future collaborations and work. T2 - NFDI-MatWerk Conference CY - Siegburg, Germany DA - 27.06.2023 KW - Referenzdaten KW - Reference data KW - Creep KW - Metadata schema KW - Syngle Crystal alloy PY - 2023 AN - OPUS4-57924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus A1 - Bayerlein, Bernd A1 - Birkholz, H. A1 - von Hartrott, P. A1 - Waitelonis, J. A1 - Sack, H. T1 - PMDco - Platform MaterialDigital Core Ontology: Achieving High-Quality & Reliable FAIR Data 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 poster 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 - DVM Arbeitskreis Betriebsfestigkeit - Potenziale der Betriebsfestigkeit in Zeiten des technologischen und gesellschaftlichen Wandels CY - Munich, Germany DA - 11.10.2023 KW - Digitalization KW - Semantic Web Technologies KW - FAIR KW - Data Interoperability KW - PMD Core Ontology PY - 2023 AN - OPUS4-58602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -