TY - CONF A1 - Schilling, Markus T1 - Towards digitalization of materials in PMD: An application ontology of the tensile test N2 - Due to the diversity of materials and the processes associated with their production and use, the complexity of the lifecycles of materials and the multitude of academic and industrial researchers participating in generation of data for material design impose a huge challenge. The topical goal of digitalizing materials and processes can only be adequately addressed by consolidating the efforts of all stakeholders in this field. There are many scattered activities, but there is a demand for an elimination of redundancies as well as an advance in acceptance and a common basis in the digitalization of materials. Furthermore, data analysis methods play an important role in both, the experimental and simulation-based digital description of materials, but they have been poorly structured so far. Therefore, the two joint projects Platform Material Digital (PMD, materialdigital.de) and Materials open Laboratory (Mat-o-Lab, matolab.de) aim to contribute to a standardized description of data processing methods in materials research. Besides stimulating the formation of a collaborative community in this respect, their main technical goals are the quality assurance of the processes and the output data, the acquisition and definition of their accuracy as well as the interoperability between applications. In this regard, data management in accordance with the FAIR (findability, accessibility, interoperability, reuseability) principles is addressed. There is a common agreement in the scientific community following current discussions that data is supposed to be conform to these principles. This includes storage, processing and querying of data in a preferably standardized form. To meet the challenge to contextualize material data in a way that is consistent with all stakeholders, all necessary information on the condition of the material including production and application-related changes have to be made available via a uniform, machine-readable description. For this purpose, ontologies are to be used since they allow for machine-understandable knowledge representations and conceptualizations that are needed for data management and the digitalization in the field of materials science. As first efforts in PMD and Mat-o-Lab, application ontologies are created to explicitly describe processes and test methods. Thereby, the well-known tensile test of metals at room temperature was described ontologically in accordance with the respective ISO standard 6892-1:2019-11. The efforts in creating this tensile test application ontology are shown in this presentation. Especially, the path of ontology development based on standards to be pursued is focused, which is in accordance with the generic recommendations for ontology development and which is supposed to be exemplary for the creation of other application ontologies. T2 - VirtMet: 1st International Workshop on Metrology for Virtual Measuring Instruments and Digital Twins CY - Online meeting DA - 21.09.2021 KW - Platform Material Digital (PMD) KW - Ontology KW - Tensile test KW - Standard KW - Ontology development PY - 2021 AN - OPUS4-53481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chen, Yue T1 - Ontopanel: a diagrams.net plugin for graphical semantic modelling N2 - Ontologies that represent a map of the concepts and relationships between them, are becoming an effective solution for data standardization and integration of different resources in the field of materials science, as efficient data storage and management is the building block of material digitization. However, building a domain ontology is not a simple task. It requires not only a collaborative effort between ontologists and domain experts, but also the modeling approaches and tools play a key role in the process. Among all approaches, graphical representation of domain ontologies based on standard conceptual modeling languages is widely used because of its intuitiveness and simplicity. Various tools have been developed to realize this approach in an intuitive way, such as Protégé plugins and web visualization tools. The Materials-open-Lab (MatOLab) project, which aims to develop ontologies and workflows in accordance with testing standards for the materials science and engineering domains, adopted a UML (Unified Modeling Language) approach based on the diagrams.net. It is a powerful, popular, open-source graphical editor. In practical case studies, however, many users’ needs could not be met, such as reusing ontology, conversion, and data mapping. Users must switch between different tools to achieve a certain step, and thereby invariably increase learning cost. The lack of validation also leads to incorrect diagrams and results for users who are not familiar with the ontology rules. To address these issues, we designed Ontopanel, a diagrams.net-based plugin that includes a set of pipeline tools for semantic modeling: importing and displaying protégé-like ontologies, converting diagrams to OWL, validating diagrams by OWL rules, and mapping data. It uses diagrams.net as the front-end for method modeling and Django as the back-end for data processing. As a web-based tool, it is very easy to expand its functionality to meet changing practical needs. T2 - MSE 2022 CY - Darmstadt, Germany DA - 27.09.2022 KW - Ontology KW - Tools KW - Material digital KW - Mat-o-lab KW - Graphic design KW - Ontology development KW - Data mapping KW - FAIR KW - Materials testing PY - 2022 AN - OPUS4-55884 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Han, Ying T1 - The influence of aging and mean stress on fatigue of Al-alloy EN AW-2618A N2 - In this study, the influence of aging and mean stress on fatigue of the aluminium-alloy EN AW-2618A is investigated. Therefore axial fatigue tests are carried out on smooth specimens. The experiments show that the fatigue life decreases with increasing mean stress. Furthermore, the tests with the overaged specimens demonstrate that the number of cycles to failure is decreasing with increasing aging time. T2 - LCF9 CY - Berlin, Germany DA - 21.06.2022 KW - Fatigue KW - Aluminium alloy KW - EN AW-2618A KW - Damage Behavior PY - 2022 AN - OPUS4-55125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abel, Andreas A1 - Zapala, P. A1 - Michels, H. A1 - Skrotzki, Birgit T1 - Materials applications of iron aluminide (FeAl), (WAFEAL) T1 - Werkstoffanwendungen für Eisenaluminide (FeAl), (WAFEAL) N2 - The increasing importance of resource availability and closed-loop material cycles are driving materials research to reduce alloying content in conventional materials or even substitute them with more sustainable alternatives. Intermetallic iron aluminide alloys (FeAl) present a potential alternative. Many alloy concepts for improved high-temperature properties or ductility have already been successfully implemented in casting technologies on a laboratory scale. However, successful testing of FeAl alloys on an industrial scale was still pending at the beginning of the project. Therefore, the aim of the project was to develop simulation based casting concepts for industrial casting processes using the base alloy Fe-26Al-4Mo-0.5Ti-1B and to narrow down process limits by means of hot cracking tests. Findings were transferred into practice-oriented guidelines for casting of iron aluminides, which is accessible to future applicants in SMEs. The focus was placed on centrifugal casting combined with investment casting or die casting. In addition to numerous design and casting process parameters, heat treatments and alloying additions (Al, Mo, B) were varied to determine the influence of alloying elements on castability, microstructure and mechanical properties. Data from microstructure analyses (microscopic imaging, determination of grain sizes as well as phase compositions and volume fractions, fractography), mechanical tests (hardness measurements, compression tests, ambient and high-temperature tensile tests, creep tests) as well as measurements of thermophysical properties could be generated on the base alloy. Correlations of materials data with process variables allowed conclusions to be drawn on strengthening mechanisms and ductility of the alloy and how they can be controlled in terms of processing and component design. Successful casting of highly complex components with thin wall thicknesses and optimised alloy compositions points out prospects for new fields of application. 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 Hochtemperatureigenschaften 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 bestimmen. 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. T2 - FVV Transfer + Netzwerktreffen | Informationstagung – Frühjahr 2023 CY - Würzburg, Germany DA - 29.03.2023 KW - Fe-Al alloys KW - Intermetallics KW - Iron aluminides KW - Microstructure-property-correlation KW - High temperature mechanical properties KW - Creep data KW - Tensile data KW - Fractography KW - Casting PY - 2023 VL - R604 SP - 1 EP - 32 PB - FVV e. V. CY - Frankfurt a.M. AN - OPUS4-57247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisenbart, M. T1 - Development of an ontology for the lifecycle of copper and copper alloys N2 - Efforts towards digitalization in the material science and technology community have enhanced in the last years. In 2019 the German digitalization initiative platform „MaterialDigital“1 (MD) has been started. Numerous projects concerning digitalization, including the copper related project „KupferDigital“ (copper digital) have been initiated under the umbrella of MD. The initiative strives to address numerous issues concerning data access, exchange, security, provenance and sovereignty. Heterogeneous data origin, storage and evaluation often result in problems concerning comparability and reproducibility of scientific and technological results. In many cases material data are recorded, but the methods of testing are insufficiently described, or such information is not communicated along with the raw data. The material data can also have numerous different formats such as paper printouts, pdfs, excel sheets or csv-files. Hence, gathering and integrating material data from different sources is challenging for potential users like materials scientists and engineers, especially if there are contradictory data where the reasons for contradictions is not clear due their vague description. In order to address these problems, data should comply to the so called „FAIR“ principle which calls for data to be findable, accessible, interoperable, and reusable (FAIR)2 and hence be accessible via so-called decentralized but interconnected data spaces. By using knowledge representation withontologies, data can be enriched with meaning and the methods of the testing procedures can be accurately provided. In this presentation we want to introduce our approach to such knowledge representation based on a high-throughput alloy development process for Cu-based alloys³ along with characterization techniques such as hardness testing and microstructural characterization (e.g. EBSD – Electron Backscattered Diffraction). T2 - Copper Alloys Conference CY - Dusseldorf, Germany DA - 22.11.2022 KW - Copper KW - Life cycle KW - Ontology PY - 2022 AN - OPUS4-56406 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd 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 - Shakeel, Y. T1 - NFDI-MatWerk - Reference Datasets N2 - Within NFDI-MatWerk (“National Research Data Infrastructure for Material Sciences”/ “Nationale Forschungsdateninfrastruktur für Materialwissenschaften und Werkstofftechnik“), the Task Area Materials Data Infrastructure (TA-MDI) will provide tools and services to easily store, share, search, and analyze data and metadata. Such a digital materials environment will ensure data integrity, provenance, and authorship. The MatWerk consortium aims to develop specific solutions jointly with Participant Projects (PPs), which are scientific groups or institutes covering different domains, from theory and simulations to experiments. The Data Exploitation Methods group of the Karlsruhe Institute of Technology-Steinbuch Centre of Computing, as part of TA-MDI, is developing specific solutions in close collaboration with three PPs. PP07, together with the University of Stuttgart, aims at the image-based prediction of the material properties of stochastic microstructures using large-scale supercomputers. PP13, in cooperation with the University of Saarland, focuses on tomographic methods at various scales in materials research. PP18, together with the Federal Institute for Materials Research and Testing (“Bundesanstalt für Materialforschung und -prüfung”), aspires to define the criteria for materials reference datasets and usage analytics. The requirements and goals are comparable for each PP: their research outputs, which are scientific datasets, should conform to the FAIR (Findable, Accessible, Interoperable, Reusable) principles. We aim to shape them from a data management perspective making use of the FAIR Digital Object concept, including structured metadata and storage solutions. The results will be a blueprint which will act as a reference for future datasets. Even though the collaboration is in an early stage, the initial steps already show the added value of this approach. This research has been supported by the Federal Ministry of Education and Research (BMBF) – funding code M532701 / the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - project number NFDI 38/1, project no. 460247524. T2 - HMC Conference 2022 CY - Online meeting DA - 05.10.2022 KW - NFDI KW - NFDI-MatWerk KW - Reference Data KW - FAIR KW - Creep PY - 2022 AN - OPUS4-56611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Sonntag, Nadja A1 - Jürgens, M. A1 - Uhlemann, Patrick A1 - Skrotzki, Birgit A1 - Olbricht, Jürgen T1 - Datasets for Service-Like Creep-Fatigue Experiments on Grade P92 Steel N2 - The dataset contains experimental mechanical data from complex service-like creep-fatigue experiments performed isothermally at 620 °C and a low strain amplitude of 0.2 % on tempered martensite-ferritic grade P92 steel. The data sets in text file format provide cyclic deformation (min. and max. stresses) and the total (hysteresis) data of all recorded fatigue cycles for three different creep-fatigue experiments: 1) a standard relaxation fatigue (RF) test with symmetrical dwell times of three minutes introduced at minimum and maximum strain, 2) a fully strain-controlled service-like relaxation (SLR) test combining these three-minute peak strain dwells with a 30-minute dwell in between at zero strain, and 3) a partly stress-controlled service-like creep (SLC) test combining the three-minute peak strain dwells with 30-minute dwells at constant stress. Further information on data and data acquisition, analysis, and experimental details are given in “Experimental Data from Service-Like Creep-Fatigue Experiments on Grade P92 Steel”, submitted to Data in Brief. Additional analyses of these datasets, as well as experimental findings and discussions are presented in “Creep-Fatigue of P92 in Service-Like Tests with Combined Stress- and Strain-Controlled Dwell Times”, submitted to International Journal of Fatigue. KW - Creep-fatigue KW - Stress relaxation KW - Dwell-Fatigue KW - Tempered martensite-ferritic steel PY - 2022 DO - https://doi.org/10.5281/zenodo.7198218 PB - Zenodo CY - Geneva AN - OPUS4-55995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radners, Jan T1 - Aluminum High Temperature Fatigue N2 - The high operating temperatures of radial compressor wheels in exhaust gas turbochargers lead to abchange in the original microstructure of the heat-resistant aluminum alloy EN AW-2618A (overaging). This is caused by thermal loads that are close to the age hardening temperature and can even exceed it for a short time. The aging mechanisms have been investigated together with low cycle fatigue (LCF), thermomechanical fatigue (TMF) and creep up to max. 190 °C in previous research projects. The behavior of the alloy under high cycle fatigue (HCF) and the influence of load spectra have hardly been investigated. Since the operating temperatures of centrifugal compressors are expected to increase in the future, this research project investigated the HCF behavior at 230 °C, a test temperature significantly higher than the age hardening temperature. The objectives of the project were to establish a suitable experimental database, to understand the relevant microstructural processes, and to further develop and adapt suitable models and evaluation methods. In addition to a basic characterization of the HCF behavior in the initial condition T61, the experimental investigation program included targeted mechanical tests to isolate the influencing factors of mean stress (𝑅 = −1, 𝑅 = 0.1), material overaging (T61, 10 h/230 °C, 1000 h/230 °C), test temperature (20 °C, 230 °C), test frequency (0.2 Hz, 20 Hz) as well as variable amplitudes. On this basis, the models and evaluation methods developed in the previous projects were adapted and further developed to reflect thermal and mechanical loads in the lifetime assessment. T2 - The FVV Transfer + Networking Event (Herbst 2023) CY - Würzburg, Germany DA - 04.10.2023 KW - Aluminum alloys KW - Fatigue KW - EN AW-2618A PY - 2023 AN - OPUS4-58537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus 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 - JOUR A1 - Eddah, Mustapha A1 - Markötter, Henning A1 - Mieller, Björn A1 - Widjaja, Martinus Putra A1 - Beckmann, Jörg A1 - Bruno, Giovanni T1 - Multi-energy high dynamic range synchrotron X-ray computed tomography N2 - Synchrotron X-ray computed tomography (SXCT) is regularly used in materials science to correlate structural properties with macroscopic properties and to optimize manufacturing processes. The X-ray beam energy must be adapted to the sample properties, such as size and density. If both strongly and weakly absorbing materials are present, the contrast to the weakly absorbing materials is lost, resulting in image artifacts and a poor signal-tonoise ratio (SNR). One particular example is a low-temperature co-fired ceramics (LTCC), in which metal connections are embedded in a ceramic matrix and form 3-dimensional conducting structures. This article describes a method of combining SXCT scans acquired at different beam energies, significantly reducing metal artifacts, and improving image quality. We show how to solve the difficult task of merging the scans at low and high beam energy. Our proposed merging approach achieves up to 35 % improvement in SNR within ceramic regions adjacent to metallic conductors. In this way, previously inaccessible regions within the ceramic structure close to the metallic conductors are made accessible. The paper further discusses methodological requirements, limitations, and potential extensions of the presented multi-energy SXCT merging technique. KW - Synchrotron computed tomography KW - Reconstruction algorithm KW - High dynamic range KW - Data merging KW - Low-temperature cofired ceramics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652339 DO - https://doi.org/10.1016/j.tmater.2025.100079 SN - 2949-673X VL - 9 SP - 1 EP - 10 PB - Elsevier CY - Amsterdam AN - OPUS4-65233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens T1 - Binder Jetting of Advanced Ceramics N2 - The Binder Jetting BJ process is one of the most versatile additive manufacturing technologies in use. In this process a binder is locally jetted into a powder bed for the consolidation of a 3D structure, layer by layer. Basically, all materials which can be provided as a flowable powder and, thus, spreadable to a thin layer, can be processed. Metals, ceramics and polymers are processable, but also materials from nature, such as sand, wood sawdust and insect frass. Moreover, the BJ technology is adapted to large building volumes of some cubic meters easily. Besides these striking advantages, the manufacture of ceramic parts by BJ is still challenging, as the packing density of the powder bed is generally too low and the particle size of a flowable powder too large for a successful densification of printed parts in a subsequent sintering step to an advanced ceramic product. After an introduction of binder jetting in general and highlighting some examples, strategies for obtaining dense ceramic parts by BJ will be introduced. T2 - yCAM 2022 CY - Barcelona, Spain DA - 08.11.2022 KW - Additive Manufacturing KW - Ceramics PY - 2022 AN - OPUS4-59887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rütters, H. A1 - Fischer, S. A1 - Le, Quynh A1 - Bettge, Dirk A1 - Bäßler, Ralph A1 - Maßmann, J. A1 - Ostertag-Henning, C. A1 - Wolf, J. Lennard A1 - Pumpa, M. A1 - Lubenau, U. A1 - Knauer, S. A1 - Jaeger, P. A1 - Neumann, A. A1 - Svensson, K. A1 - Lempp, C. A1 - Menezes, F. A1 - Hagemann, B. T1 - Towards defining reasonable minimum composition thresholds – impacts of variable CO2 stream compositions on transport, injection and storage N2 - The collaborative project “Impacts of impurities in CO2 streams captured from different emitters in a regional cluster on transport, injection and storage (CLUSTER)” aimed to set up recommendations on how to define “reasonable minimum composition thresholds” that CO2 streams should meet when accessing CO2 transport pipeline networks. Within CLUSTER, we investigated potential impacts of CO2 streams with different and temporally variable compositions and mass flow rates along the whole CCS chain. Investigations included, amongst others, impacts on: Corrosion of pipeline steel, pipeline network design and related transport costs, alteration of well bore cements, pressure development and rock integrity, geochemical reactions, and petrophysical and geomechanical rock properties. All investigations are based on a generic CCS chain scenario. In this scenario, CO2 streams are captured from a spatial cluster of eleven emitters and collected in a regional pipeline network. Emitters comprise seven fossil fuel-fired power plants equipped with different capture technologies, two cement plants, one refinery and one integrated iron and steel plant. In total, 19.78 Mio t CO2 (including impurities) are captured in the emitter cluster annually. The combined CO2 stream is transported in a trunk line with a length of 400 km (100 km of these offshore) and is injected into five generic storage structures. The storage reservoirs are saline aquifers of the Buntsandstein. The investigations revealed beneficial and deteriorating impacts of different impurities and combinations thereof. Overall, no fundamental technical obstacles for transporting, injecting and storing CO2 streams of the modelled variable compositions and mass flow rates were observed. Based on the results, the CLUSTER project team recommends not to define “minimum composition thresholds” for CO2 streams as strict threshold values for each individual impurity in the stream. Instead, CO2 stream compositions and variabilities for specific CCS projects should be constrained with regard to a set of parameters including i) the overall CO2 content, ii) maximum contents of relevant impurities or elements, iii) acceptable variability of CO2 stream composition, and iv) impurity combinations to be avoided. T2 - 15th International Conference on Greenhouse Gas Control Technologies, GHGT-15 CY - Online meeting DA - 15.03.2021 KW - Corrosion KW - Impurities KW - CO2 quality KW - Pipeline network KW - Whole-chain CCS scenario KW - Recommendations PY - 2021 DO - https://doi.org/10.2139/ssrn.3816427 SP - 1 EP - 18 AN - OPUS4-52418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Suitability of Metallic Materials in CC(U)S Applications N2 - Commercially available carbon steels are suitable for compression and pipelines as long as moisture content and impurities are limited. (water 50 to 100 ppmv, SO2 and NO2 ca. 100 ppmv). Corrosion rates increase with increasing water content. (0.2 – 20 mm/a). Condensation of acids and therefore droplet formation is always possible, even at low water contents. A low SO2 content within the CO2-stream might be more important than a low water content. Cr13-steels showed a general susceptibility to shallow pitting and pitting. So, they seem to be not suitable for CCUS applications. Low alloyed steels showed better corrosion behavior. � (predictable uniform corrosion) For direct contact with saline aquifer fluids only high alloyed steels shall be used. T2 - EUROCORR 2021 CY - Budapest, Hungary DA - 20.09.2021 KW - Carbon capture storage KW - Corrosion KW - Steel KW - CCS KW - CCU KW - CO2 PY - 2021 AN - OPUS4-53461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea T1 - Combination of layerwise slurry deposition and binder jetting (lsd-print) for the additive manufacturing of advanced ceramic materials N2 - Powder bed technologies are amongst the most successful Additive Manufacturing (AM) techniques. Powder bed fusion and binder jetting especially are leading AM technologies for metals and polymers, thanks to their high productivity and scalability. The application of these techniques to most ceramics has been difficult so far, because of the challenges related to the deposition of homogeneous powder layers when using fine powders. In this context, the “layerwise slurry deposition” (LSD) has been developed as a layer deposition method which enables the use of powder bed AM technologies also for advanced ceramic materials. The layerwise slurry deposition consists of the layer-by-layer deposition of a ceramic slurry by means of a doctor blade, in which the slurry is deposited and dried to achieve a highly packed powder layer. This offers high flexibility in the ceramic feedstock used, especially concerning material and particle size. The LSD technology can be combined with binder jetting to develop the so-called “LSDprint” process for the additive manufacturing of ceramics. The LSDprint technology combines the high-speed printing of binder jetting with the possibility of producing a variety of high-quality ceramics with properties comparable to those achieved by traditional processing. In this presentation, the LSD process will be introduced and several examples of application ranging from silicate to high-performance ceramics will be shown. Recent developments towards the scale-up and industrialization of this process will be discussed, alongside future perspectives for the multi-material additive manufacturing. T2 - Shaping 8 CY - Dübendorf, Switzerland DA - 14.09.2022 KW - Additive Manufacturing KW - 3D printing KW - Ceramics PY - 2022 AN - OPUS4-56523 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens T1 - Ceramic Processing with Light N2 - In order to be able to manipulate ceramic powder compacts and ceramic suspensions (slurries) in their volume with light, a minimum transparency of the materials is required. Compared to polymers and metals, ceramic materials are characterized by the fact that they have a wide electronic band gap and therefore a wide optical window of transparency. The optical window generally ranges from less than 0.3 µm to 5 µm wavelength. Therefore, to focus light into the volume of a ceramic powder compact, its light scattering properties need to be tailored. In this study, we present the physical background and material development strategies for the application of two-photon polymerization (2PP), Xolography and selective volumetric sintering for the additive manufacturing of structures in the volume of ceramic slips and green compacts. T2 - CMCEE 14 CY - Budapest, Hungary DA - 18.08.2024 KW - Ceramic KW - Additive manufacturing KW - Light PY - 2024 AN - OPUS4-60892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolsch, Nico T1 - Enabling online quality control of powder deposition for 3d printing in microgravity N2 - 3D printing or additive manufacturing in space is of great value for long-term human spaceflight missions and space stations, conveniently offering access to a ‘virtual warehouse’ of tools and spare parts on the push of a button. The process only needs one type of feedstock such as powder or filament and only as much material as the final part requires, giving it a huge weight benefit over traditional subtractive methods. While 3D printers are already operational on the ISS since 2014, the utilized processes are only capable of manufacturing relatively low strength parts from polymers not suitable for many tools or critical components. To gain access to high quality metal prints, a modified Laser Powder Bed Fusion (LPBF) process was developed to stabilize the critical powder bed in microgravity through a gas flow [2]. This setup was able to generate a (miniature) steel wrench during parabolic flights, but a reliable layer deposition has raised challenges due to the combination of gas flow parameters with microgravity conditions. Furthermore, the quality and density of the powder bed, which is critical for the process, cannot be examined afterward on the ground. This is due to hyper gravity phases during the flight that are influencing the properties of the powder bed. In this paper, the challenges of the layer deposition are revised, and the subsequent evolution of the recoating system explained. Later, the challenges of an in-situ quality control, evaluation, and quantification of the properties of the powder bed are examined. As a solution, a high-resolution line-scanner is proposed and its implementation int the compact LPBF system demonstrated. Its ability to measure common defects such as ridges in the deposited layer is shown in experiments at normal gravity. As an illustration, Figure 1 shows an extreme case of the formation of ridges. T2 - European Conference on Spacecraft Structures Materials and Environmental Testing CY - Toulouse, France DA - 28.03.2023 KW - Additive manufacturing KW - In-space manufacturing KW - Online quality control KW - Microgravity KW - Powder deposition PY - 2023 AN - OPUS4-57249 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Melo Bernardino, Raphael A1 - Valentino, S. A1 - Franchin, G. A1 - Günster, Jens A1 - Zocca, Andrea T1 - Manufacturing of ceramic components with internal channels by a novel additive/subtractive hybridizazion process N2 - A new approach for fabrication of ceramic components with inner channels is proposed, as a result of the combination of two additive and one subtractive manufacturing processes. In this project, porcelain parts are manufactured by the Layerwise Slurry Deposition (LSD) process, meanwhile end milling and Direct Ink Writing (DIW) are applied to create channels on the surface of the deposited ceramic. Unique to the LSD process is the Formation of a freestanding powder bed with a mechanical strength comparable to conventional slip casted ceramic green bodies. Combining these three processes allows the manufacturing of ceramic objects containing an internal path of ink, which in this case was a graphite-based ink that can be further eliminated by heat treatment to obtain a porcelain object embedded with channels. The results show the capabilities of this method and its potential to fabricate not only parts with inner channels, but also multi-material and multi-functional components (such as integrated electronic circuits). KW - Additive Manufacturing KW - Layerwise Slurry Deposition KW - Hybrid Manufacturing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510012 UR - https://www.sciencedirect.com/science/article/pii/S2666539520300109?via%3Dihub DO - https://doi.org/10.1016/j.oceram.2020.100010 VL - 2 SP - 100010 PB - Elsevier Ltd. AN - OPUS4-51001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilbig, Janka A1 - Borges de Oliveira, F. A1 - Obaton, A.-F. A1 - Schwentenwein, M. A1 - Rübner, Katrin A1 - Günster, Jens T1 - Defect detection in additively manufactured lattices N2 - This paper investigates fast and inexpensive measurement methods for defect detection in parts produced by Additive Manufacturing (AM) with special focus on lattice parts made of ceramics. By Lithography-based Ceramic Manufacturing, parts were built both without defects and with typical defects intentionally introduced. These defects were investigated and confirmed by industrial X-ray Computed Tomography. Alternative inexpensive methods were applied afterwards on the parts such as weighing, volume determination by Archimedes method and gas permeability measurement. The results showed, that defects resulting in around 20% of change in volume and mass could be separated from parts free of defects by determination of mass or volume. Minor defects were not detectable as they were in the range of process-related fluctuations. Permeability measurement did not allow to safely identify parts with defects. The measurement methods investigated can be easily integrated in AM process chains to support quality control. KW - Additive manufacturing KW - Quality assurance KW - Defect detection KW - Lattices KW - Ceramics PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513547 DO - https://doi.org/10.1016/j.oceram.2020.100020 VL - 3 SP - 100020 PB - Elsevier Ltd. AN - OPUS4-51354 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sänger, Johanna A1 - Riechers, Birte A1 - Pauw, Brian Richard A1 - Günster, Jens T1 - Transparent feedstocks for photon-based additve manufacturing technologies for powder processing of ceramics N2 - Photon-based additive manufacturing technologies such as SLA, DLP, LCM, moreover volumetric two-photon-polymerization, Xolography and holographic technologies promise the highest accuracy and dimensional freedom. But to transfer the light through the feedstock it needs sufficient transparency at the used light wavelength. Ceramic particles used for powder processing routes act as scattering sites and therefore hinder the light transmission, unless… The particle size and particle size distribution are chosen small and narrow enough. Particles which are smaller than roughly 1/10th of the light wavelength, mostly nanoparticles around 5nm size, decrease scattering vastly. This turns resins even with homogeneously distributed ceramic weight fraction of up to 80% transparent again. Feedstocks could be prepared for the highly accurate two-photon-polymerization gaining the smallest yttria stabilized zirconia structures with a resolution of 500nm and unique mechanical properties. The same feedstocks could be applied to DLP and LCM as layer-by-layer AM-technologies for bigger parts. Hybridizing both technologies lead to ceramic parts with microscopic accuracy at macroscopic dimensions. The feedstock was even applied to the volumetric Xolography with the highest transparency requirement so far and to versatile and flexible holographic AM. Highly filled nano-particle containing transparent ceramic feedstocks open the way for technical ceramics in high precision manufacturing where the performance and durability and accessibility are increased and created by the unique ceramic properties such as mechanical strength, chemical and thermal resistance and biocompatibility T2 - 14th International Conference on Ceramic Materials and Components for Energy and Environmental Systems CY - Budapest, Hungary DA - 18.08.2024 KW - Transparent KW - Ceramic KW - Additive manufacturing PY - 2024 AN - OPUS4-60891 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Diener, S. A1 - Zocca, Andrea A1 - Günster, Jens T1 - Literature review: Methods for achieving high powder bed densities in ceramic powder bed based additive manufacturing N2 - In additive manufacturing the powder bed based processes binder jetting and powder bed fusion are increasingly used also for the production of ceramics. Final part properties depend to a high percentage on the powder bed density. Therefore, the aim is to use the best combination of powder deposition method and powder which leads to a high packing of the particles. The influence of flowability, powder properties and deposition process on the powder bed density is discussed and the different deposition processes including slurry-based ones are reviewed. It turns out that powder bed density reached by slurry-based layer deposition exceeds conventional powder deposition, however, layer drying and depowdering are extra steps or more time-consuming for the slurry route. Depending on the material properties needed the most suitable process for the part has to be selected. KW - Additive Manufacturing KW - Powder-based processes KW - Powder bed density PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534992 DO - https://doi.org/10.1016/j.oceram.2021.100191 VL - 8 SP - 100191 PB - Elsevier Ltd. AN - OPUS4-53499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Seamless Science in Platform MaterialDigital (PMD): Demonstration of Semantic Data Integration as Good Practices 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) 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 on a prototypical basis 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 poster presentation illustrates demonstrators developed and deployed within the PMD project. Semantically anchored using the mid-level PMD Core Ontology (PMDco), they address data transformation leading to a novel data management which is based on semantic integrated data. The PMD data acquisition pipeline (DAP), which is fueled by traditional, diverse data formats, and a pipeline applying an electronic laboratory notebook (ELN) as data source are displayed. Additionally, the efficient combination of diverse datasets originating from different sources is demonstrated by the representation of a use case dealing with the well-known Orowan relation. T2 - Materials Science and Engineering Congress 2024 CY - Darmstadt, Germany DA - 24.09.2024 KW - Semantic Data KW - Data Integration KW - Digitalization KW - Demonstrators PY - 2024 AN - OPUS4-61136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - Structural dynamics in metallic glasses due to Thermal and Mechanical Stress N2 - This talk addresses aging induced property changes of metallic glasses. Priority is given thermally and mechanically induced structural changes, of which the time-dependent dynamics is tracked using coherent scattering. Strong intermittency is observed and accelerated transport is seen at the smallest applied stresses. These findings have significant implications for how metallic glass components respond in realistic service conditions. T2 - Seminar Universität Münster 2020 CY - Münster, Germany DA - 01.12.2020 KW - Metallic glasses KW - Structure PY - 2020 AN - OPUS4-60714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holzer, Marco T1 - Glass fracture surface energy calculated from crystal structure and bond-energy data N2 - Enhancing the fracture toughness is still one of the major challenges in the field of oxide glasses. To screen different glass systems for promising candidates, a theoretical expression for the fracture surface energy, G, linked to the fracture toughness, KIc, is thus of interest. Extending our earlier work on nucleation and surface energies [1], we present a simple approach for predicting the fracture surface energy of oxide glasses, G using readily available crystallographic structure data and diatomic bond energies. The proposed method assumes that G of glass equals the surface fracture energy of the weakest fracture (cleavage) plane of the isochemical crystal. For non-isochemically crystallizing glasses, an average G is calculated from the weighed fracture energy data of the constitutional crystal phases according to Conradt [2]. Our predictions yield good agreement with the glass density- and chemical bond energy-based prediction model of Rouxel [3] and with experimentally obtained G values known at present. [1] C. Tielemann, S. Reinsch, R. Maass, J. Deubener, R. Müller, J. Non-Cryst. Solids 2022, 14, 100093 [2] R. Conradt, J. Non-Cryst. Solids 2004, 345-346, 16 [3] R., Tanguy, Scripta Materialia 2017, 109-13, 137 T2 - DPG Spring Meeting of the Condensed Matter Section CY - Dresden, Germany DA - 26.03.2023 KW - Fracture Toughness KW - Oxide Glasses KW - Surface Energy PY - 2023 AN - OPUS4-58414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hickel, Tilmann A1 - Richter, Silke A1 - Bitzek, E. A1 - Ávila Calderón, Luis A1 - Gedsun, A. A1 - Forti, M. A1 - Hammerschmidt, T. A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit T1 - NFDI-MatWerk/IUC02 Definition for Reference Data of Materials N2 - This definition was agreed within the infrastructure use case IUC02 “Framework for curation and distribution of reference datasets” of the consortium NFDI-MatWerk. It is broadly formulated to cover experimental and simulation MSE data and will be developed further in agreement with the MSE community. KW - Referenzdaten KW - Digitalisierung KW - NFDI-MatWerk KW - Research Data Management KW - Reference Data PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611688 DO - https://doi.org/10.5281/zenodo.11667673 PB - Zenodo CY - Geneva AN - OPUS4-61168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Günster, Jens T1 - Research and carrier in governmental research institute in Japan and Germany N2 - Being invited to Japan in 1996 as a Humboldt/STA was on of the most exciting things in my life. Not that it is on an absolute scale the most exciting thing still, but at that time, just after finalizing my PhD and thinking what is coming next, it was. KW - Networking PY - 2022 DO - https://doi.org/10.11470/oubutsu.91.2_115 SN - 0369-8009 VL - 91 IS - 2 SP - 115 EP - 117 PB - Gakkai CY - Tōkyō AN - OPUS4-54462 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Study of Polyaniline/Silicon Dioxide based Coating on Carbon Steel in Artificial Geothermal Brine N2 - By using the available resources in Indonesia, such as silicon dioxide and marine coating base, the PANI/SiO2 modified alkyd coating was able to protect carbon steel in a deaerated artificial geothermal water. The screening of coatings shows that the modification by adding individual pigment was not sufficient to protect carbon steel even during a short-term exposure, indicated by the discoloration after only seven days of exposure. Electrochemical tests indicated that there was no significant change in the Ecorr between the coated and uncoated carbon steel at room temperature. At 150 °C, the coated carbon steel has a lower potential than that of carbon steel, indicating that the coating is protecting carbon steel cathodically or slowing down the corrosion reaction. Finally, a long-term exposure test confirmed that the PANI/SiO2 modified coating successfully protects the carbon steel in the Sibayak artificial geothermal water up to 150 °C for 6 months. T2 - World Geothermal Congress CY - Online meeting DA - 15.06.2021 KW - Coatings KW - Corrosion KW - Polyaniline KW - Sibayak KW - SiO2 KW - Geothermal PY - 2021 AN - OPUS4-52831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea T1 - Continuous layer deposition for the Additive Manufacturing of ceramics by Layerwise Slurry Deposition (LSD-print) N2 - Powder bed technologies are amongst the most successful Additive Manufacturing (AM) techniques. The application of these techniques to most ceramics has been difficult so far, because of the challenges related to the deposition of homogeneous powder layers when using fine powders. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method enabling the use of powder bed AM technologies also for advanced ceramic materials. The layerwise slurry deposition consists of the layer-by-layer deposition of a ceramic slurry by means of a doctor blade, in which the slurry is deposited and dried to achieve a highly packed powder. Not only very fine, submicron powders can be processed with low organics, but also the dense powder bed provides excellent support to the parts built. The LSD technology can be combined with binder jetting to develop the so-called “LSD-print” process. LSD-print combines the high-speed printing of binder jetting with the possibility of producing a variety of high-quality ceramics with properties comparable to traditional processing. The latest development of this technology shows that it is possible to print ceramic parts in a continuous process by depositing a layer onto a rotating platform, growing a powder bed following a spiral motion. The unique mechanical stability of the layers in LSD-print allows to grow a powder bed several centimeters thick without any lateral support. The continuous layer deposition allows to achieve a productivity more than 10X higher compared to the linear deposition, approaching a build volume of 1 liter/hour. T2 - 3rd Global Conference and Exhibition on Smart Additive Manufacturing, Design & Evaluation Smart MADE CY - Osaka, Japan DA - 10.04.2024 KW - Additive Manufacturing KW - Ceramic KW - Layerwise slurry deposition KW - LSD-print KW - Slurry KW - Binder jetting PY - 2024 AN - OPUS4-60055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens A1 - Sänger, Johanna A1 - Pauw, Brian Richard T1 - Two-Photon-Polymerization for Ceramics Powder Processing N2 - Manipulating ceramic powder compacts and ceramic suspensions (slurries) within their volume with light requires a minimum transparency of the materials. Compared to polymers and metals, ceramic materials are unique as they offer a wide electronic band gap and thus a wide optical window of transparency. The optical window typically ranges from below 0.3 µm up to 5µm wavelength. Hence, to penetrate with laser light into the volume of a ceramic powder compound its light scattering properties need to be investigated and tailored. In the present study we introduce the physical background and material development strategies to apply two-photon-polymerization (2PP) for the additive manufacture of filigree structures within the volume of ceramic slurries. T2 - DKG Jahrestagung 2023 CY - Jena, Germany DA - 27.03.2023 KW - Additive Manufacturing KW - Transparent ceramics PY - 2023 AN - OPUS4-59880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens T1 - Continuous layer deposition for the Additive Manufacturing of ceramics by Layerwise Slurry Deposition N2 - Powder bed technologies are among the most successful additive manufacturing (AM) techniques. The application of these techniques to most ceramics has been difficult due to the challenges associated with the deposition of homogeneous powder layers when using fine powders. In this context, layerwise slurry deposition (LSD) has been developed as a deposition method that enables the use of powder bed AM technologies for advanced ceramic materials. In layerwise slurry deposition, a ceramic slurry is deposited in layers using a doctor blade and dried to produce a highly compacted powder. Not only can very fine submicron powders with low organic content be processed, but the dense powder bed also provides excellent support for the manufactured parts. The latest development of this technology shows that it is possible to print ceramic parts in a continuous process by depositing a layer on a rotating platform on which a powder bed grows in a spiral motion. The unique mechanical stability of the layers in LSD printing makes it possible to build up a powder bed several centimeters thick without lateral support. Continuous layer deposition achieves more than 10 times the productivity of linear deposition, approaching a build volume of 1 liter per hour. T2 - International Conference on Additive Manufacturing Technology Frontiers CY - Xi’an, China DA - 11.04.2025 KW - Ceramic KW - advanced ceramics PY - 2025 AN - OPUS4-63963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - A unique authenticator for additively manufactured parts derived from their microstructure N2 - In the field of additive manufacturing, the ability to uniquely identify and authenticate parts is crucial for certification, logistics, and anti-counterfeiting efforts. This study introduces a novel methodology that leverages the intrinsic microstructural features of additively manufactured components for their identification, authentication, and traceability. Unlike traditional tagging methods, such as embedding QR codes on the surface [1] or within the volume of parts, this approach requires no alteration to the printing process, as it utilizes naturally occurring microstructural characteristics. The proposed workflow [2] involves the analysis of 3D micro-computed tomography data to identify specific voids that meet predefined identification criteria. This method is demonstrated on a batch of 20 parts manufactured with identical process parameters, proving capable of achieving unambiguous identification and authentication. By establishing a tamper-proof link between the physical part and its digital counterpart, this methodology effectively bridges the physical and digital realms. This not only enhances the traceability of additively manufactured parts but also provides a robust tool for integrating digital materials, parts databases, and product passports with their physical counterparts. T2 - Artificial Intelligence in MSE CY - Bochum, Germany DA - 18.11.2025 KW - Authentication KW - Additive Manufacturing KW - Non-destructive testing PY - 2025 AN - OPUS4-65204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rashidi, Reza A1 - Vaerst, Olivia A1 - Riechers, Birte A1 - Rösner, Harald A1 - Wilde, Gerhard A1 - Maaß, Robert T1 - Atomic-scale strain fluctuations as an origin for elastic microstructures in metallic glasses N2 - Metallic glasses (MGs) exhibit an elastic microstructure that spans from a few to hundreds of nanometers, the origin of which continues to remain poorly understood. Here we employ four-dimensional scanning transmission electron microscopy (4D-STEM) on a Zr65Cu25Al10 (at. %) bulk MG. Mapping local diffraction patterns over representative areas also probed elastically with automated nanoindentation, two comparable correlation length scales have been identified. Specifically, local diffraction patterns are analyzed with respect to their ellipticity, revealing systematic fluctuations between positive and negative volumetric strains. A power spectrum analysis of the strain fluctuations returns a dominant length scale of the order of 100 nm, which is very much compatible with what elastic property mapping indicates. Annealing reduces the magnitude of the statistical strain fluctuations, without strongly affecting the associated fluctuation length scale. These findings demonstrate that atomic-scale strains are very likely the origin of the structurally unexpected large elastic fluctuations obtained in nanoscale contact mechanics experiments. KW - Metallic glass KW - 4D-STEM KW - Strain anisotropy KW - Nanoindentation KW - Elastic microstructure KW - Heterogeneities PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654991 DO - https://doi.org/10.1016/j.actamat.2026.121982 SN - 1359-6454 VL - 308 SP - 1 EP - 8 PB - Elsevier Inc. AN - OPUS4-65499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Bettge, Dirk T1 - Electrochemical behaviors of casing steel/mortar interface in CO2 saturated aquifer fluid N2 - To reveal the corrosion resistance of casing steel/mortar interface in CO2 injection condition, sandwich samples were prepared and exposed up to 20 weeks in aquifer fluid under 10 MPa and 60 °C. Cross section analysis revealed the crevice corrosion as main mechanism instead of pitting corrosion, which would be expected to happen in the extremely high Chloride concentration. Detailed analysis using EDS line scan shown the slow diffusion of Chloride, suggesting why pitting did not happen after 20 weeks. To mimic the passivated steel surface, the steel coupon was passivated in simulated pore solution having pH 13.5 for 42 days. The passivated coupon was further exposed to NGB solution for 28 days. Electrochemical characterization was performed along the exposure processes to reveal the change in impedance, indicating the corrosion resistance of steel casing/mortar interface. T2 - EUROCORR 2022 CY - Berlin, Germany DA - 28.08.2022 KW - Corrosion KW - CO2 quality KW - Pipeline network KW - CCS PY - 2022 SP - 859 EP - 865 PB - European Federation of Corrosion AN - OPUS4-55622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Lena T1 - Laser beam melting additive manufacturing at μ-gravity N2 - In-space manufacturing (ISM) provides the opportunity to manufacture and repair critical components on future human spaceflight missions. For explorations to Mars and beyond, ISM is a key strategy not only due to the long travel distances and high costs of supply from earth but also to be able to safely work in space for years. Human spaceflight is still dependent on shipments from earth that can fail for several reasons. ISM is a valuable alternative to ensure the timely and safe resupply of space missions. With additive manufacturing (AM) technologies, components are built directly from a 3D computer-aided-design (CAD) model which offers the advantages of freedom of design and the production of complex and ready-to-use parts. A virtual tool box with 3D models in space or the supply of information instead of components from earth to space can strongly benefit future missions. For industrial use, most research has focused on laser based additive manufacturing processes such as laser beam melting (LBM) where metallic powder particles are spread into a uniform powder bed and melted by a laser to the desired shape. In the absence of gravity, the handling of metal powders, which is essential for the process, is challenging. We present an evolution of an AM system, where a gas flow throughout the powder bed is applied to stabilize the powder bed. This is needed to compensate for the missing gravitational forces in microgravity experiments on parabolic flight campaigns. The system consists of a porous building platform acting as a filter for the fixation of metal particles in a gas flow. It is driven by reduced pressure established by a vacuum pump underneath the platform. The system creates a drag force that directs the particles towards the porous building platform, similar to the effect of the gravitational force. The AM system with its gas-flow-assisted powder deposition has been tested in several parabolic flight campaigns, and stainless-steel powder has successfully been processed during microgravity conditions. Different powder recoating mechanisms have been investigated to assess the homogeneous distribution of the powder as well as the attachment of the next layer to the powder bed. These mechanisms included different container designs with parallel double blades and with a V-shape at the bottom, and a roller recoating system. The samples presented are the first metal parts ever manufactured using LBM in μ-gravity. In addition to manufacturing in a μ-gravity environment, the experiments have shown the feasibility to manufacture components at different accelerations during the parabolic flight: hyper gravity (1.8 g), μ-gravity (< 0.01 g) and 1 g. Recent results will also be presented describing the application of this LBM setup in a parabolic flight campaign with mixed lunar, martian and µ-gravity acceleration, during which the processing of a lunar regolith simulant powder was tested. For ISM, the development and testing of the proposed AM system demonstrates that LBM can be considered a viable technology for the manufacturing of metal and ceramic parts in a μ-gravity or reduced-gravity environment. T2 - International Conference on Advanced Manufacturing CY - Online meeting DA - 07.03.2022 KW - μ-gravity KW - In-space manufacturing KW - Additive manufacturing KW - Laser beam melting KW - Microgravity KW - Stainless steel KW - Lunar regolith simulant PY - 2022 AN - OPUS4-54450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Lena T1 - Powder based Additive Manufacturing in Space N2 - Abstract of the event: 'The area of New Space is a vastly growing and dynamic field with a high innovative potential and many exciting ideas. After decades where activities in space were dominated and funded mainly by governmental agencies, a new industry is forming and new business models are being developed around ideas like satellite-based internet, space travel, space mining, geo-monitoring etc. For space applications, lightweight design is crucial to keep the costs at a minimum. This Innovation Day will introduce the field of New Space and present the variety of exciting opportunities that arise for composites based on their excellent lightweight potential.' Another research area is now arising in the field of 3D printing or additive manufacturing of fiber composite materials in space. At the event, we presented on the opportunities and our experiences of using a powder based additive manufacturing process for in-space manufacturing applications. T2 - CU Innovation Day - New opportunities and applications in space with composites CY - Online meeting DA - 29.03.2022 KW - μ-gravity KW - In-space manufacturing KW - Additive manufacturing KW - Microgravity KW - Powder PY - 2022 AN - OPUS4-54559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller-Elmau, Johanna T1 - 2PP of ceramic – What’s next? N2 - Photon-based additive manufacturing technologies such as SLA, DLP, LCM, moreover volumetric two-photon-polymerization (2PP), Xolography and holographic technologies promise the highest accuracy and dimensional freedom. To transfer the light through the feedstock it needs sufficient transparency. Ceramic particles used for powder processing routes act as scattering sites and therefore hinder the light transmission, unless… The particle size and particle size distribution are chosen small and narrow enough. Particles smaller than roughly 1/10th of the light wavelength, mostly nanoparticles around 5nm size, decrease scattering vastly. This turns resins even with homogeneously distributed ceramic weight fraction of up to 80% transparent again. Feedstocks were prepared for the highly accurate two-photon-polymerization gaining the smallest yttria stabilized zirconia structures with a resolution of 500nm and unique mechanical properties. The same feedstock was applied to DLP and LCM as layer-by-layer AM-technologies for bigger parts. Hybridizing both technologies enables ceramic parts with microscopic accuracy at macroscopic dimensions. The feedstock was even applied to the volumetric Xolography with the highest transparency requirement so far and to versatile and flexible holographic AM. What are the next steps? Can those proof-of -concept studies be transferred to industrial applications and what are the hurdles on the way? How to make the stretch between fundamental research and application-oriented development? T2 - ECERS CY - Dresden, Germany DA - 31.08.2025 KW - Tranparent KW - Ceramic KW - Two-photon-polymerization PY - 2025 AN - OPUS4-64939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chinellato, Fabio A1 - Wilbig, Janka A1 - Al-Sabbagh, Dominik A1 - Colombo, P. A1 - Günster, Jens T1 - Gas flow assisted powder deposition for enhanced flowability of fine powders: 3D printing of alpha-tricalcium phosphate N2 - The possibility of creating patient-specific individual implants makes Additive Manufacturing technologies of special interest for the medical sector. For substitution of bone defects, powder based Additive Manufacturing by Binder Jetting is a suitable method to produce complex scaffold-like structures made of bioceramics with easily adapted geometries and controlled porosity. The process inherent residual porosity in the printed part, even though desired as it supports bone ingrowth, also leads to limited mechanical strength. Currently, bioceramic scaffolds made by Binder Jetting feature suitable biocompatible and biodegradable properties, while a sufficient mechanical stability is rather challenging. The purpose of this work is to apply the gas flow assisted powder deposition introduced in 2014 by Zocca et al., to the powder bed during printing of bioceramic tablets and scaffolds using α-TCP powder as feedstock. This enables exploiting the advantages of an increased powder bed density, thereby improving the mechanical properties of the printed parts. KW - Additive Manufacturing KW - Binder Jetting KW - Gas flow assisted powder deposition KW - Alpha-tricalcium phosphate KW - Scaffold PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510138 DO - https://doi.org/10.1016/j.oceram.2020.100003 SN - 2666-5395 VL - 1 SP - 100003 PB - Elsevier Ltd. AN - OPUS4-51013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Preliminary Study on Al2O3 Sol-Gel Coating for Corrosion Protection of Martensitic Stainless Steel in Artificial Geothermal Water N2 - Al2O3 coatings are often used as protective layers on steels against electrochemical and high-temperature corrosion because they are chemically inert and stable at elevated temperatures. This study presents preliminary work on the possibilities of using Al2O3 sol-gel coatings for corrosion protection of martensitic stainless steels in geothermal environments. Al2O3 sol-gel coatings were applied on UNS S42000, which is known to be susceptible to uniform and localized corrosion. The coated steel specimens were then tested in two types of artificial geothermal water, which simulate the geothermal fluids found in Sibayak (SBY), Indonesia, and North German Basin (NGB), Germany, respectively. SBY has pH 4 and 1.5 g/L of chloride ions, whereas NGB has a pH of 6 and 166 g/L of chloride ions. All experiments were carried out in autoclaves at 150 °C and 1 MPa under the deaerated condition. Evaluations were performed by investigating the surface profiles of both uncoated and coated steels before and after the corrosion test using a Laser Scanning Microscope (LSM) and Scanning Electron Microscope (SEM). Finally, Electrochemical Impedance Spectroscopy (EIS) was performed to compare the corrosion resistance of Al2O3 coated steels in SBY and NGB solutions. It was observed from the corrosion test that Al2O3 coatings are more suitable for use in the geothermal water with a higher pH. T2 - AMPP Annual International Corrosion Conference 2021 CY - Online Meeting DA - 19.04.2021 KW - Protective coating KW - Sol-gel coating KW - Geothermal KW - Martensitic steel KW - Corrosion PY - 2021 AN - OPUS4-52500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rütters, H. A1 - Fischer, S. A1 - Le, Quynh Hoa A1 - Bettge, Dirk A1 - Bäßler, Ralph A1 - Maßmann, J. A1 - Ostertag-Henning, C. A1 - Lennard Wolf, J. A1 - Pumpa, M. A1 - Lubenau, U. A1 - Knauer, S. A1 - Jaeger, P. A1 - Neumann, A. A1 - Svensson, K. A1 - Pöllmann, H. A1 - Lempp, C. A1 - Menezes, F. A1 - Hagemann, B. T1 - Towards Defining Reasonable Minimum Composition Thresholds – Impacts of Variable CO2 Stream Compositions on Transport, Injection and Storage N2 - The collaborative project “Impacts of impurities in CO2 streams captured from different emitters in a regional cluster on transport, injection and storage (CLUSTER)” aimed to set up recommendations on how to define “reasonable minimum composition thresholds” that CO2 streams should meet when accessing CO2 transport pipeline networks. Within CLUSTER, we investigated potential impacts of CO2 streams with different and temporally variable compositions and mass flow rates along the whole CCS chain. Investigations included, amongst others, impacts on: • corrosion of pipeline steel, • pipeline network design and related transport costs, • alteration of well bore cements, • pressure development and rock integrity, • geochemical reactions, and • petrophysical and geomechanical rock properties. All investigations are based on a generic CCS chain scenario. In this scenario, CO2 streams are captured from a spatial cluster of eleven emitters and collected in a regional pipeline network. Emitters comprise seven fossil fuel-fired power plants equipped with different capture technologies, two cement plants, one refinery and one integrated iron and steel plant. In total, 19.78 Mio t CO2 (including impurities) are captured in the emitter cluster annually. The combined CO2 stream is transported in a trunk line with a length of 400 km (100 km of these offshore) and is injected into five generic storage structures. The storage reservoirs are saline aquifers of the Buntsandstein. The investigations revealed beneficial and deteriorating impacts of different impurities and combinations thereof. Overall, no fundamental technical obstacles for transporting, injecting and storing CO2 streams of the modelled variable compositions and mass flow rates were observed. Based on the results, the CLUSTER project team recommends not to define “minimum composition thresholds” for CO2 streams as strict threshold values for each individual impurity in the stream. Instead, CO2 stream compositions and variabilities for specific CCS projects should be constrained with regard to a set of parameters including i) the overall CO2 content, ii) maximum contents of relevant impurities or elements, iii) acceptable variability of CO2 stream composition, and iv) impurity combinations to be avoided. T2 - The 15th Greenhouse Gas Control Technologies Conference CY - Online meeting DA - 15.03.2021 KW - Corrosion KW - Impurities KW - CO2 quality KW - Pipeline network KW - Whole-chain CCS scenario KW - Recommendations PY - 2021 DO - https://doi.org/10.2139/ssrn.3816427 SP - 1 EP - 18 PB - Elservier AN - OPUS4-52940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brandić Lipińska, M. T1 - PAVER - Contextualizing laser sintering within a lunar technology roadmap N2 - The Global Exploration Strategy of the International Space Exploration Coordination Group (ISECG) describes a timeframe of 2020 and beyond with the ultimate aim to establish a human presence on Mars towards the 2040ies. The next steps lie on the Moon with a focus on the coming 10 years. Early lunar surface missions will establish a capability in support of lunar science and prepare and test mission operations for subsequent human exploration of Mars and long-duration human activities on the Moon. Given the extreme costs involved in the shipping of material from Earth, a prerequisite for future human exploration is the manufacturing of elements directly on the Moon’s surface. Unlike the equipment, which at the beginning will have to be brought from Earth, raw materials and energy could be available following the concept of In-Situ Resource Utilization. The ESA OSIP PAVING THE ROAD (PAVER) study investigates the use of a laser to sinter regolith into paving elements for use as roadways and launch pads thus mitigating dust issues for transport and exploration vehicles. The ESA-funded study examines the potential of using a laser (12 kW CO2 laser with spot beam up to 100 mm) for layer sintering of lunar and martian regolith powders to manufacture larger 3D elements and provide know-how for the automatic manufacture of paving elements in the lunar environment. The project contributes to the first step toward the establishment of a lunar base and will lead to the construction of equipment capable of paving areas and manufacturing 3D structures. PAVER project sets the starting point for an examination of the larger context of lunar exploration. Mission scenarios will look at different phases of lunar exploration: Robotic Lunar Exploration, Survivability, Sustainability, and Operational Phase. A proposed Technology Roadmap investigates the mission scenario and analyses how, and to which extent, laser melting/sintering will play a role in the various phases of exploration. The paper contextualizes laser sintering within selected mission scenarios and discusses the different kinds of infrastructure that can be produced at each phase of the mission. The outcome of the study includes the detailing of the TRL steps in the project and an outline of a timeline for the different elements. Covered aspects include terrain modelling such as operation pads, roadways, or towers, non-pressurized building structures to protect machinery, and habitat envelopes, to protect and shield humans against dust, micrometeoroids, and radiation. T2 - 73rd International Astronautical Congress (IAC) CY - Paris, France DA - 18.09.2022 KW - Additive manufacturing KW - ISRU KW - Infrastructure KW - Lunar habitat KW - Paving KW - Solar sintering PY - 2022 AN - OPUS4-56529 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea T1 - Additive Manufacturing for dental restorations by layerwise slurry deposition (LSD-print) technology N2 - The growing market of custom-made dental restorations offers a major potential for an application of ceramic additive manufacturing (AM). The possibility to individualize patient specific design and to establish new efficient workflows, from model generation to manufacturing, can be fully exploited by AM technologies. However, for mass customization to be truly envisioned, ceramic AM needs to achieve a level of maturity, aesthetic quality, and productivity comparable to established manufacturing processes. In this presentation, the potential of the “layerwise slurry deposition” LSD-print technology for dental applications will be explored. It has been shown in the past years that the LSD-print can be applied to advanced ceramic materials such as alumina and silicon-infiltrated silicon carbide. For these materials, the LSD-print technology combines the high-speed printing of binder jetting with the possibility of producing a variety of high-quality ceramics. The current development deals with the challenges of applying this technology to a feldspar dental material, comparing the quality of AM restorations with the equivalent material for an established CAD/CAM workflow. Preliminary results not only indicate that the AM material produced by LSD-print can be competitive in terms of mechanical properties, but also that aesthetically satisfactory restorations can be manufactured for veneers, inlays and onlays as well as single unit fixed dental prostheses (FDPs). The presentation focuses on the material and technological challenges alongside the process chain, from the printing process, to debinding, firing and finishing the restorations. T2 - XVIIIth Conference of the European Ceramic Society CY - Lyon, France DA - 02.07.2023 KW - Additive Manufacturing KW - Layerwise slurry deposition KW - dental KW - ceramic PY - 2023 AN - OPUS4-58469 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens A1 - Sänger, Johanna A1 - Pauw, Brian Richard T1 - Tailoring powder properties for the light based volumetric additive manufacture of Ceramics N2 - Manipulating ceramic powder compacts and ceramic suspensions (slurries) within their volume with light requires a minimum transparency of the materials. Compared to polymers and metals, ceramic materials are unique as they offer a wide electronic band gap and thus a wide optical window of transparency. The optical window typically ranges from below 0.3 µm up to 5µm wavelength. Hence, to penetrate with light into the volume of a ceramic powder compound, its light scattering properties need to be investigated and tailored. In the present study we introduce the physical background and material development strategies to apply two-photon-polymerization (2PP), and other volumetric methods for the additive manufacture of filigree structures within the volume of ceramic slurries. T2 - ICACC 2024 CY - Daytona Beach, Florida, USA DA - 28.01.2024 KW - Additive Manufacturing KW - Two Photon Polymerization KW - Advanced ceramics PY - 2024 AN - OPUS4-59889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Kuchenbecker, Petra A1 - Lindemann, Franziska T1 - Final report proficiency test LS BAM-5.5-2021: Measurement of the particle size distribution of ceramic powders by laser diffraction in accordance with ISO 13320 N2 - This is the final report on the proficiency test (PT) „Measurement of the particle size distribution of ceramic powders by laser diffraction”. The PT was organized by the Federal Institute for Materials Research and Testing (BAM), division 5.5 “Advanced technical ceramics”. The measurements took place from 12/2021 to 03/2022. The aim of the interlaboratory comparison was the proficiency assessment of the participating laboratories. Management and realization of PT were performed in accordance with DIN EN ISO/IEC 17043:2010. The basis of the harmonized measuring procedure and the instructions for the interlaboratory comparison was the standard ISO 13320:2020. The statistical analysis was performed in accordance with DIN ISO 13528:2020 by use of the software PROLab Plus (QuoData GmbH, Dresden, Germany). A group of 44 laboratories from 17 countries participated in the PT. Laser diffraction analyzers produced by 7 different manufacturers were used. The three test materials were commercial products. Overall, the measured characteristic values of the particle distributions (d10, d50 and d90) were in the size range between 0.5 and 25 μm. The final report contains all individual results in an anonymous way. KW - Proficiency test KW - Particle size KW - Laser light scattering PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548640 DO - https://doi.org/10.26272/opus4-54864 SP - 1 EP - 33 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-54864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Kuchenbecker, Petra A1 - Lindemann, Franziska T1 - Final report proficiency test LS BAM-5.4-2024 - Measurement of the particle size distribution of ceramic powders by laser diffraction N2 - This publication is the final report on the proficiency test (PT) LS BAM-5.4-2024 „Measurement of the particle size distribution of ceramic powders by laser diffraction”. The PT was organized by the Federal Institute for Materials Research and Testing (BAM), division 5.4 “Advanced Multi-materials Processing”, Germany. The measurements took place from 2024/05 to 2024/07. The aim of the interlaboratory comparison was the proficiency assessment of the participating laboratories. The PT was performed in accordance with DIN EN ISO/IEC 17043:2010. The harmonized measurement procedure was based on ISO 13320:2020The statistical analysis was performed in accordance with DIN ISO 13528:2020 by use of the software PROLab (QuoData GmbH, Dresden, Germany). A group of 35 laboratories from 14 countries participated in the PT. Laser diffraction analyzers produced by 7 different manufacturers were used. The three test materials were commercial ceramic powders. Overall, the measured characteristic values of the particle size distributions (d10,3, d50,3 and d90,3) were in the size range between 1 and 35 μm. The final report contains all individual results in an anonymous form. KW - Proficiency test KW - Particle size determination KW - Laser diffraction PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610602 DO - https://doi.org/10.26272/opus4-61060 SP - 1 EP - 33 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-61060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard T1 - On the cubic slip effect and creep anisotropy modeling of single crystal superalloys at intermediate temperatures (IT) N2 - Low-Temperature High Stress (LTHS) creep plays a crucial role in Ni-base Superalloys, particularly affecting components like blades near the root. Below 850°C, the precipitate microstructure remains stable, characterized by periodically arranged ’ cubic precipitates surrounded by the -matrix. In these conditions, macroscopic traces of cubic slip have been observed in <111> oriented tensile specimens, whereas their microscopic origin has been a topic of debate. Furthermore, in LTHS conditions, Superlattice Intrinsic, Extrinsic Stacking Faults (SISF/SESF), or micro-twins are also frequently reported in crept specimens. Usually, these mechanisms are investigated separately, so that a unified picture and a detailed understanding of these mechanisms and their activation conditions have only recently emerged in the literature, despite the intensive investigations of the last decades. The objective of this work is to develop a dislocation-based constitutive law that includes these recent developments. In particular, the pseudo-cubic slip mechanism is considered as resulting from the lack of hardening in <111> oriented tensile specimens and is represented by a novel estimate of the back-stresses based on the spectral decomposition of a tensorial representation of the back-stress. An additional novelty is that SISF- and SESF-related slip systems are accounted for as distinct slip systems with corresponding dislocation densities. The model has been implemented as a user-defined constitutive law for commercial Finite Element codes and identified as well as validated with data from the literature obtained with <001>, <011> and <111> oriented crystals tested in tension and compression creep. T2 - International Conference on Material Modelling (8) CY - London, GB DA - 15.07.2024 KW - Creep KW - Superalloy KW - Crystal plasticity KW - Single crystal PY - 2024 AN - OPUS4-60744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Mechanical behaviour of AM metals: Creep of LPBF 316L and low-cycle-fatigue of LMD Ti-6Al-4V N2 - Additively manufactured metallic materials have already started to find application in safety-relevant components. However, this has only happened for certain materials and specific applications and loading conditions, since there is still an extensive lack of knowledge as well as of historical data regarding their mechanical behaviour. This contribution aims to address this lack of understanding and historical data concerning the creep behaviour of the austenitic stainless steel 316L manufactured by Laser-Powder-Bed-Fusion (L-PBF) and the low-cycle-fatigue behaviour of the titanium alloy Ti-6Al-4V manufactured by Laser-Metal-Deposition (LMD). Furthermore, it aims to assess their mechanical behaviour against their conventional counterparts. With that in mind, specimens from conventional and additive materials are tested and their mechanical behaviour analysed based on characteristic curves. To understand the damage behaviours the materials are characterized by destructive and non-destructive techniques before and after failure. T2 - 1st Workshop on In-situ Monitoring and Microstructure Development in Additive Manufacturing CY - Online Meeting DA - 10.12.2020 KW - Ti-6Al-4V KW - 316L KW - Additive manufacturing KW - Creep behaviour KW - Low-cycle-fatigue behaviour PY - 2020 AN - OPUS4-51879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - Liquid Metal Embrittlement in High-Strength Steels N2 - One contribution of materials science to energy efficiency is the continuous development of novel high-performance structural materials that push the strength-ductility envelope. A prominent example are modern advanced high-strength steels (AHSSs), which have enabled considerable weight reductions in the automotive sector, thereby enabling greenhouse emission reductions. To protect such advanced alloys from property degradation via corrosion, zinc (Zn) coatings are often applied through galvanization. Whilst protective, a Zn-coating comes with problems – the AHSS substrate becomes susceptible for liquid-metal embrittlement (LME) than can be the origin of significant mechanical property degradation when liquified Zn infiltrates into the steel substrate. Being for from understood, we focus here on non-cracked environments to capture the early stages of LME. This approach revealed the nucleation and growth of nano-scale intermetallic phases inside uncracked GBs (Materials Today Advances 13, 100196, 2022), highlighting the complex multi-phase microstructure developing before cracking occurs. To shed further light on the early stages of LME in AHSSs, we also consider the microstructural evolution of interrupted welds. We discuss our findings in the context of the time-resolved substructure evolution right beneath the interface between the AHSS and the Zn-based coating and track how Zn progressively infiltrates the substrate along phase and grain boundaries. The experimental results are further corroborated with thermodynamic simulations. T2 - ASATM CY - Singapore DA - 10.01.2023 KW - Liquid-metal embrittlement KW - Steels KW - Grain boundaries KW - Micro-cracking PY - 2023 AN - OPUS4-60647 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marschall, Niklas T1 - Spinodal Decomposition in FeMnNiCoCu: Alloying effects N2 - Spinodal decomposition in multi-component alloys remains insufficiently understood, particularly when multiple driving forces govern phase evolution. Chemical thermodynamics provides reliable predictions of spinodal instabilities, but elastic energy contributions can significantly alter the boundaries of phase stability. In this work, we establish a framework to analyze phase stability in high-entropy alloys by combining Hessian-based spinodal analysis with convex hull constructions that capture miscibility gaps. This approach allows us to disentangle the roles of chemical, elastic, and kinetic factors in early-stage decomposition. Our results highlight how elastic contributions can extend the effective spinodal region beyond chemically predicted boundaries, thereby influencing microstructural pathways. This combined stability analysis offers new insights into the mechanisms governing decomposition and advancing the theoretical understanding of phase evolution in high-entropy alloys. T2 - FEMS EUROMAT 2025 CY - Granada, Spain DA - 14.09.2025 KW - High-entropy alloy KW - Elasticity KW - Phase stability KW - Hessian KW - Convex hull PY - 2025 AN - OPUS4-64263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane T1 - Elucidation of competitive oxidation/sulfidation reactions on binary ferritic alloys N2 - Ferritic-austenitic chromia-forming alloys are frequently used as boiler tubes and heat exchanger materials for fossil-,biomass, and co-fired power plants. In all applied environments several strongly corrosive gaseous species such as CO2, SO2, SO3, H2O, O2 exist, causing materials degradation by high-temperature corrosion. The elucidation of degradation mechanisms introduced by multiple gases is challenging due to the presence of different oxidizing agents contributing to the competing reactions for oxidation, sulfurization or carburization. The degradation processes can be divided into initial stages, a transitional stage and the further proceeding steady-state oxidation reaction. Especially the long-term steady-state oxidation and further materials’ life-time are strongly dependent on the initial stages. The adsorption and absorption of the reactive species at the alloy surface and the growing oxide in the initial reaction is further influenced by dissociation and re-reactions of the gas phase molecules. To understand these mechanisms from a fundamental point of view in more detail, dedicated experiments and advanced characterization techniques on various length scale need to be applied. Real-time approaches using highly energetic synchrotron X-ray diffraction showed a high potential to enlighten competitively mechanisms by following the corrosion reactions in-situ in the environment they occur. Despite various other thin film characterization techniques, time of flight secondary ion mass spectroscopy (ToF-SIMS) is a powerful tool to visualize light atoms or labeled isotopes enabling the Differentiation between different oxidizing species. It was especially shown to be applicable in challenging atmospheres containing KCl deposits or in CO/CO2/O2 environments. The present study analyses the competing oxidation/sulfidation process in a humid atmosphere on two ferritic alloys with 2 and 9 % in weight chromium by in situ energy dispersive X-ray diffraction (EDXRD) and comparative tube furnace exposure using S16O2 and H2 18O atmosphere. T2 - Conference on High Temperature Corrosion and Protection of Materials HTCPM 2021 CY - Online Meeting DA - 29.03.2021 KW - Oxidation KW - High Temperature Corrosion KW - Ferritic Alloys KW - SIMS KW - EDXRD PY - 2021 AN - OPUS4-52363 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Fedelich, Bernard ED - Cailletaud, G. ED - Cormier, J. ED - Eggeler, G. ED - Maurel, V. ED - Nazé, L. T1 - Crystal plasticity models: dislocation based N2 - The large number of TEM investigations and the regular microstructure of single-crystal nickel-base superalloys has boosted the development of a number of physically motivated constitutive laws. In contrast to the more phenomenological models discussed in the next chapter, these models use dislocation densities as internal variables. Obvious advantages are that the computed densities can be compared to TEM observations and the Deformation mechanisms can be easier translated into mathematical equations. KW - Nickel-base superalloys KW - Creep KW - Plasticity PY - 2022 SN - 978-0-12-819357-0 SP - 401 EP - 427 PB - Elsevier Inc. ET - 1 AN - OPUS4-53436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenberg, Rainer T1 - Modelling of hydrogen-induced ductility loss in titanium-based hydrogen storage N2 - One promising solution for decarbonisation is the use of hydrogen as energy carrier. Besides its exceptional advantages like high calorific value, better safety and non-existent harmful emissions, one major challenge is still hydrogen embrittlement of Ttitanium alloys used as a hydrogen storage. In this work, a method is presented that can numerically model and determine a threshold concentration of hydrogen in solid solution responsible for a sudden ductile-to-brittle transition. The origin of this sudden loss of ductility lies in the segregation kinetics thermodynamics that is modelled together with an elastoplastic fracture mechanics model. Starting from experimental fracture mechanics test data, a meaningful coupling mechanism was found for the fracture mechanics cohesive zone model in the form of a segregation-modified cohesive energy that triggers an acceleration of crack extension above defined concentration values. It can be demonstrated that above a threshold of only few atomic percent hydrogen in the solid solution, the segregated hydrogen concentration exceeds 20 at.%. The current results present a mechanism that enables the modelling of the sudden ductility loss triggered by a segregation-affected crack energy expression in titanium alloys exposed to hydrogen. This method is not only applicable to other various materials but can also be a substantial benefit for the safety assessment of hydrogen storage devices. T2 - 5th EMMC International Workshop 2025 CY - Vienna, Austria DA - 08.04.2025 KW - Segregation Transition KW - Hydrogen Embrittlement KW - Titanium Alloys KW - Crack Propagation KW - Ductile-to-Brittle Transition PY - 2025 AN - OPUS4-63177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard T1 - Experimental and analytical investigation of Low Cycle Fatigue Damage at notches in a polycrystalline Nickel base superalloy N2 - Turbine blades often contain cylindric holes used to generate an air film that protects the blade alloy from the hot gases. These cooling holes of diameter around one mm are drilled by laser through the thickness of the blades. Unfortunately, the resulting stress concentration and the drilling-induced damage are known to favor crack initiation from the holes. It is thus necessary to assess the impact of these cooling holes on the structural integrity of the blades. Since cracks initiate very readily, the fatigue life of the components is mainly controlled by the propagation of the cracks in the stress gradient induced by the holes. For this purpose, displacement controlled high-temperature LCF (Low-Cycle-Fatigue) tests were performed with center hole specimens of a coarse-grained Nickel base Superalloy. The tests were stopped after a defined load drop. In addition, crack propagation tests with Double Edge Notch specimens were performed. Moreover, specimens with different hole surface finishes were investigated, which showed a detrimental effect of the hole surface roughness. In parallel, an evaluation of the LCF tests based on a fracture mechanics-based model (Madia et al., Eng. Fract. Mech., 2018) has been applied. Thereby, the specimen life is controlled by the crack propagation time until failure. Crack growth is controlled by a modified NASGRO equation accounting for large-scale yielding and a progressive build-up of crack closure. The initial crack size has been derived from the measurements of defects around the borehole. A reasonable agreement between predicted and measured lifetimes is observed if one keeps in mind the large uncertainty regarding the effective shape of the cracks. T2 - 23rd European Conference on Fracture CY - Funchal, Madeira, Portugal DA - 27.06.2022 KW - Nickel-base superalloys KW - Notches KW - LCF PY - 2022 AN - OPUS4-55338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Murugan, Jegatheesan T1 - Extending Grain Boundary Phase Diagrams to Multi-Phase Boundary Diagrams N2 - Phase diagrams serve as fundamental blueprints for comprehending material behaviour and guiding material design. However, the phase diagrams are largely available only for the bulk phases. The thermodynamic properties and phase behaviour of defects, such as grain boundaries (GBs) and phase boundaries (PBs), are equally important for the safe design of materials. Recently, we developed CALPHAD-integrated density-based phase field model (DPF) to calculate the thermodynamic data of GBs. In the model, the GB was represented by a continuous relative atomic density field with reference to a single bulk density and a Gibbs free energy functional was derived. In this work, we extend the DPF model by re-deriving the Gibbs free energy functional for PBs lying between heterogeneous bulk phases of different atomic densities. Here, we use phase-specific atomic densities to normalize the phase properties on either side of the PB such that the relative density fields are continuous across the interface. Using the model, the multi-phase interfacial thermodynamic data are obtained and related phase boundary diagrams are constructed. We study binary and ternary Fe-Mn-X alloy systems. In the Fe-Mn multi-phase boundary diagram, a shrinkage in the α-ferrite region is observed. Integrated with CALPHAD databases, the developed model may be used to calculate the segregation of solute to the PBs, paving way to manipulate segregation behaviour for microstructure design. T2 - FEMS 2025 EUROMAT CY - Granada, Spain DA - 14.09.2025 KW - Phase boundary diagrams KW - Interface thermodynamics KW - CALPHAD PY - 2025 AN - OPUS4-64425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Darvishi Kamachali, Reza T1 - Co-segregation phenomena and stability issues in high-entropy alloys using density-based phase-field modelling N2 - Several recent studies have revealed that the phase decomposition in medium- and high-entropy alloys is triggered by solute segregation at grain boundaries. The chemically complex nature of these alloys already clues that such segregation in materials should be something more than the interaction between solutes and grain boundary, but also affected by the solute-solute interactions during the segregation. In fact, experiments indicate the significance of such solute-solute interaction. Yet, the mechanisms of co-segregation in multi-component alloys are rather challenging to explore and rarely studied quantitatively. Recently, a CALPHAD-integrated density-based phase-field model has been proposed for studying grain boundary phenomena. Several applications of this model have shown its expansive capacity for investigating grain boundary segregation and phase behavior. In this talk, the applications of this model to studying co-segregation phenomena and grain boundary phase diagrams in multi-component alloys are presented ––the term ‘co-segregation’ here refers to co-evolution and any mutual interplay among the solutes and grain boundary during the segregation. In particular, the iron-based ternary and quaternary alloys are discussed. I show how a grain boundary may have its own miscibility gap and how this immiscibility can influence the co-segregation behavior. As an alternative to grain boundary phase diagrams, rather suited for binary and ternary alloys, a new concept of co-segregation maps for screening and segregation design in multi-component alloys is presented. Applying the co-segregation maps, the nonlinear Mn and Cr co-segregation in Fe-Co-Mn-Cr is discussed. T2 - 19th International Conference on Diffusion in Solids and Liquids (DSL-2023) CY - Crete, Greece DA - 26.06.2023 KW - CALPHAD KW - Co-segregation KW - Phase-field Simulation PY - 2023 AN - OPUS4-57965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard T1 - On the modeling of creep anisotropy of single Crystal Superalloys at low temperatures and high stresses N2 - Low-Temperature High Stress (LTHS) creep plays a crucial role in Ni-base Superalloys, particularly affecting components like blades near the root. Below 850°C, the precipitate microstructure remains stable, characterized by periodically arranged ’ cubic precipitates surrounded by the -matrix. In these conditions, macroscopic traces of cubic slip have been observed in <111> oriented tensile specimens, whereas their microscopic origin has been a topic of debate [1]. Later, it was shown by Discrete Dislocations simulations [2] that the apparent cubic slip is rather due to a lack of hardening in <111> specimens, which is related to the special dislocation structures that develop in this case. Furthermore, in LTHS conditions, Superlattice Intrinsic, Extrinsic Stacking Faults (SISF/SESF), or micro-twins are also frequently reported in crept specimens. Usually, these mechanisms are investigated separately, so that a unified picture and a detailed understanding of these mechanisms and their activation conditions have only recently emerged in the literature, despite the intensive investigations of the last decades [3-5]. The objective of this work is to develop a dislocation-based constitutive law that includes these recent developments. In particular, the pseudo-cubic slip mechanism is considered as resulting from the lack of hardening in <111> oriented tensile specimens and is represented by a novel estimate of the back-stresses based on the spectral decomposition of a tensorial representation of the back-stress. An additional novelty is that SISF- and SESF-related slip systems are accounted for as distinct slip systems with corresponding dislocation densities. The model has been implemented as a user-defined constitutive law for commercial Finite Element codes and identified as well as validated with data from the literature obtained with <001>, <011> and <111> oriented crystals [3,6]. It can be used in combination with a Representative Volume Element of the grain structure for simulation of creep in polycrystalline superalloys, including additively manufactured materials [7]. T2 - Materials Structure and Micromechanics of Fracture CY - Brno, Czech Republic DA - 23.06.2025 KW - Creep KW - Superalloy KW - Crystal plasticity KW - Single crystal KW - Model PY - 2025 AN - OPUS4-63551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ganesh, Rahul T1 - Numerical calculation of ΔCTOD for thermomechanical fatigue crack growth N2 - The cyclic crack tip opening displacement ΔCTOD is a promising loading Parameter to quantify the crack propagation under thermomechanical fatigue (TMF). In this work, suitable techniques are investigated and compared for an accurate calculation of ΔCTOD under TMF loading using a viscoplastic temperature dependent material model. It turned out that collapsed special crack tip elements give the best results. An efficient FEM-technique is developed to simulate the incremental crack growth by successive remeshing, whereby the deformations and internal state variables are mapped from the old mesh onto the new one. The developed techniques are demonstrated and discussed for two-dimensional examples like TMF-specimens. Recommendations are made regarding important numerical control parameters like optimal size of crack tip elements, length of crack growth increment in relation to plastic zone size and ΔCTOD value. T2 - 53. Tagung des Arbeitskreises "Bruchmechanik und Bauteilsicherheit" CY - Online meeting DA - 18.02.2021 KW - Crack tip opening displacement KW - Thermomechanical fatigue KW - Crack growth PY - 2021 AN - OPUS4-52520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ávila Calderón, Luis A1 - Schriever, Sina T1 - BAM Reference Data: Creep of Single-Crystal Ni-Based Superalloy CMSX-6 N2 - This publication provides comprehensive metadata and test results of constant force creep tests according to DIN EN ISO 204:2019-4 on the single crystal Ni-based superalloy CMSX-6 at T = 980 °C and initial stresses between 140 MPa and 230 MPa. The tests were carried out in an accredited test laboratory using calibrated measuring equipment. The data were audited and are BAM reference data. KW - NFDI-MatWerk KW - Digitalisierung KW - CMSX-6 KW - Creep KW - Reference Data KW - Referenzdaten KW - Ni-Based Superalloy PY - 2024 DO - https://doi.org/10.5281/zenodo.13937986 PB - Zenodo CY - Geneva AN - OPUS4-61649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leo, Reinhold A1 - Sobol, Oded A1 - Hango, Silas Ithete A1 - Saliwan Neumann, Romeo A1 - Askar, Enis A1 - Boellinghaus, Thomas T1 - Ex-situ investigation of the compatibility of Duplex Stainless Steel for high-pressure hydrogen applications N2 - The key to a successful transition into clean energy carriers such as hydrogen requires the construction of safe transportation pipelines made of alloys which are not susceptible to hydrogen assisted cracking. Duplex Stainless Steels (DSS) are considered as a proper class for components because of their many distinctive qualities. As this consideration depends strongly on the susceptibility level to Hydrogen Assisted Cracking (HAC), the DSS class has been broadly investigated under electrochemical charging conditions. In this work, the interplay between several factors controlling the level of HAC, was examined using light microscopy, high-pressure gaseous hydrogen pre-charging, Electron Backscatter Diffraction (EBSD), tensile testing, fractography and hydrogen concentration measurements using Carrier Gas Hot Extraction (CGHE). The effect of gaseous hydrogen on the mechanical properties with the role of hydrogen induced phase transformation have been investigated both in unused material and in high pressure pipeline section. In contrary to the common electrochemical charging described broadly in the literature, no significant martensitic phase transformation of the austenitic phase was observed. On the other hand, the influence of hydrogen on parameters such as elongation at fracture and reduction of area was noticeable. It is concluded based on the performance of DSS in gaseous hydrogen, that this material has a better potential for utilization in hydrogen applications. As for future experiments, the intention is to analyse the impact of high-pressure gaseous hydrogen on the welded components of this grade, and under mechanical load using the hollow specimen technique. T2 - 5th International Conference on Metals and Hydrogen CY - Ghent, Belgium DA - 14.10.2025 KW - High-Pressure Hydrogen KW - Pipelines KW - Duplex Stainless Steels KW - Hydrogen Assisted Cracking KW - Hollow Specimen Technique PY - 2025 SN - 978-9-08179-424-4 SP - 1 EP - 19 AN - OPUS4-64426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Suárez Ocano, Patricia A1 - Agudo Jácome, Leonardo A1 - Lopez-Galilea, I. A1 - Darvishi Kamachali, Reza A1 - Fries, S. G. T1 - Data regarding the experimental findings compared with CALPHAD calculations of the AlMo0.5NbTa0.5TiZr refractory high entropy superalloy N2 - This contribution contains the raw data used to compare experimental results with thermodynamic calculations using the CALPHAD method, which is related to the research article “The AlMo0.5NbTa0.5TiZr refractory high entropy superalloy: experimental findings and comparison with calculations using the CALPHAD method” [1] , and therefore this article can be used as a basis for interpreting the data contained therein. The AlMo0.5NbTa0.5TiZr refractory superalloy was characterized in the cast and annealed condition (1400 °C for 24 h) in order to measure grain size and to identify and measure the size and area fraction of the phases present. The raw data of this article include X-ray diffraction (XRD) measurements, microstructural characterization by scanning and transmission electron microscopy (SEM and TEM), and elemental analysis by energy dispersive X-ray spectroscopy (EDX). XRD includes the determination of phases and the lattice parameters (A2, B2, and hexagonal structure). Microstructural analysis by scanning and transmission electron microscopy includes (1) identification of composition, size, and volume fraction of the present phases and (2) determination of grain size. Based on these experimental data, it is possible to identify similarities and discrepancies with the data calculated using the CALPHAD method for the alloy under study in Ref. [1] , which provides the basis for better and more efficient development of reliable databases. KW - Microstructural characterization KW - Refractory high entropy alloys KW - Scanning electron microscopy KW - Transmission electron microscopy PY - 2023 DO - https://doi.org/10.17632/d742ccty5f.4 PB - Mendeley Data CY - Oxford, UK AN - OPUS4-56861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Elfetni, Seif A1 - Darvishi Kamachali, Reza T1 - Application of deep learning to multi-phase-field modelling and simulation N2 - Recent advances in Deep Learning (DL) have significantly impacted the field of materials modelling. DL tools have been recently considered as promising tools to address the complex relationships among processing, microstructure and property of materials. The thermal stability of polycrystalline materials is a highly interesting and complex problem that could be addressed using DL techniques. The Multi-Phase-Field (MPF) method has emerged as a powerful tool for addressing grain growth phenomena from multiple perspectives. Unlike sharp-interface based methods, the MPF approach bypasses the need for detailed information on individual grains. In this work, we use DL to address issues related to MPF simulations of grain growth including numerical efficiency, computing speed, and resource consumption. This presents specific challenges for high-performance computing (HPC) due to the large datasets and complex computations required by both MPF and DL methods. We study various 3D microstructure settings with the goal of accelerating the simulation process while exploring different physical effects. In particular, the impact of grain boundary and triple junction energies on grain growth are to be investigated. The results will be presented in terms of the evolving size and shape distribution of the grains. T2 - Euromat 2023 CY - Frankfurt a. M., Germany DA - 03.09.2023 KW - Phase-Field Simulation KW - Microstructure Evolution KW - Physics-informed Neural Network KW - Machine Learning PY - 2023 AN - OPUS4-58225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kindrachuk, Vitaliy T1 - Computational investigation of DGG kinetics by phase-field method N2 - Non-equilibrium microstructure evolution in additive manufacturing (AM) is a major barrier for establishing a safe and sustainable application of AM in industrial processes. The constant heat source in the AM continuously affects the just-solidified grains beneath the melting pool, leading to directional grain growth (DGG). While real-time measurements of the non-equilibrium microstructure evolution is challenging, here developing a computational framework to systematically explore DGG becomes imperative. We have advanced a comprehensive approach, integrating mean-field modeling and phase-field simulations, to elucidate the dynamics of DGG under an external driving force. Our simulations unveil a steady-state power-law grain growth kinetics during DGG, characterized by the interplay between curvature-driven dynamics at grain boundary junctions and directional driving forces. T2 - Tagung DGM Additive Fertigung CY - Bremen, Germany DA - 12.06.2024 KW - Directional grain growth KW - Phase-field simulation KW - Additive manufacturing PY - 2024 AN - OPUS4-60750 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Kianinejad, Kaveh T1 - Multiscale Modelling of Creep Anisotropy in Additively Manufactured IN738LC N2 - Excellent creep resistance at elevated temperatures, i.e. T / Tm> 0.5, due to gamma-gamma’ microstructure is one of the main properties of nickel-based superalloys. Due to its great importance for industrial applications, much research has been devoted to understanding the underlying deformation mechanism in a broad spectrum of temperature and loading conditions. Additive Manufactured (AMed) nickel-based superalloys, while being governed by similar \gamma-gamma’ microstructure, exhibit AM-process specific microstructural characteristics, such as columnar grains, firm crystallographic texture (typically <001> fibre texture parallel to build direction) and compositional inhomogeneity, which in turn leads to anisotropic creep response in both stationary and tertiary phases. Despite the recent insights on the correlation between process parameters and the resulting microstructure, these materials' anisotropic creep behaviour and corresponding deformation mechanism are insufficiently understood. One reason is the lack of capable material models that link the microstructure to the mechanical behaviour. Within the present work, a multiscale approach has been developed to overcome this challenge by combining microstructure-based mesoscale and phenomenological macroscale models. The mesoscale model utilizes the Crystal Plasticity Finite Element Method (CPFEM) to include the microstructural characteristics and the relevant deformation mechanism on the polycrystalline scale. The mesoscale model was then used to perform virtual creep experiments required to calibrate the macroscale model. The developed approach has been applied to characterise the creep behaviour of AMed IN738LC. The effect of different slip systems, crystallographical texture, grain morphology, and Grain Boundary Sliding (GBS) on creep anisotropy at 850°C has been investigated. The approach's ability to capture the AM-specific characteristics and link them to the observed macroscale anisotropic response has been demonstrated, and the contribution of primary underlying deformation mechanisms to creep anisotropy has been elucidated. KW - Creep anisotropy KW - Crystal plasticity KW - Addtively manufactured Nickel-based Alloys alloy PY - 2025 SP - 1 EP - 135 PB - RWTH Aachen CY - Aachen AN - OPUS4-64598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard T1 - Experimental and analytical investigation of high temperature fatigue crack growth at notches in a polycrystalline Nickel base superalloy N2 - The scatter of fatigue crack growth data can become significant for coarse grained materials. By using a probabilistic description of crack propagation as the foundation of a lifetime prediction model, lifetime scatter of laboratory specimens can be reproduced. However, the lifetime of real components is subjected to additional scattering factors such as surface condition or uncertainty regarding direction and shape of emerging cracks. These factors need to be addressed in order to exploit the advantages of probabilistic description, i.e. the reduction of unnecessary conservatisms. High temperature LCF (Low-Cycle-Fatigue) tests were performed with center hole specimens of a coarse-grained Nickel base Superalloy. In addition, crack propagation tests with Double Edge Notch specimens were performed. A procedure to detect the shape of the starting crack that combines the potential drop method and induction thermography was developed. The geometry and the number of notches were varied. Moreover, specimen with different hole surface finishes were investigated, which showed a detrimental effect of the roughness of the hole surface. The results have been compared to predictions of a probabilistic tool for the estimation of lcf lifetime that has been calibrated beforehand on laboratory specimens with and without notches. In parallel, a fracture mechanics-based lifetime model was developed, which includes the initial crack size as a critical parameter. Thereby, the influence of the large grain size (>1mm), and the shape of the starting crack at the notch were considered. Acknowledgements The investigations are conducted as part of the joint research program COOREFLEX-Turbo in the frame of AG Turbo. The work is supported by Siemens AG and the Bundesministerium für Wirtschaft und Technologie (BMWi) as per resolution of the German Federal Parliament under grant number 03ET7071E. T2 - Low Cycle Fatigue 9 CY - Berlin, Germany DA - 21.06.2022 KW - Nickel-base superalloys KW - Notches KW - LCF PY - 2022 AN - OPUS4-55335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marschall, Niklas T1 - Phase Decomposition in Magnetic FeMnNiCoCu Alloy System N2 - Phase decomposition in multi-component high-entropy alloys (HEAs) can take complex routes, on the one hand, leading to various safety concerns during their service and, on the other hand, opening vast opportunities for intelligent alloy design. Insights into a controlled decomposition of initially homogeneous HEAs are therefore essential. In this study, we combine the recently developed multi-component elastic energy theory with CALPHAD databases to study potentially magnetic FeMnNiCoCu alloy system. In a first approximation, the elastic energy is added to the Gibbs free energy to reconstruct the thermodynamic phase diagrams and consequent phase decompositions. Our results show that depending on the alloy composition and the temperature, Cu-rich and FeCo-rich phases emerge, which lead to the formation of distinct magnetic phases of different extents. The spatial redistribution of elements is studied through Fourier analysis, auto-, and cross-correlation, revealing the contribution of the thermodynamic, kinetic and elastic driving forces throughout this process. These dissembled analysis methods contribute to a more comprehensive understanding of multi-component alloys and the role of elastic energy in their phase decomposition. T2 - MSE2024 CY - Darmstadt, Germany DA - 23.09.2024 KW - High-Entropy Alloy KW - Elasticity KW - Spinodal Decomposition KW - FeMnNiCoCu PY - 2024 AN - OPUS4-62341 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wang, Lei A1 - Darvishi Kamachali, Reza T1 - Density-based Thermodynamics of Microstructure Defects N2 - Systematic microstructure design requires reliable thermodynamic descriptions and phase diagrams of each and all microstructure elements. While such descriptions are well established for most bulk phases, thermodynamic assessment of crystal defects is greatly challenged by their individualistic aspects. In this talk, we present a density-based thermodynamic concept to describe defects based on available bulk thermodynamic data. Here dealing with grain boundaries (GBs), we apply this concept to compute GB (phase) diagram. Applications to segregation engineering of GBs in bulk and nanocrystalline alloys will be presented. We further develop this model to include the effect of elastic interactions due to atom size mismatch and obtain the corresponding GB (phase) diagram for the ternary Al-Cu-Li system. T2 - TMS 2021 CY - Online meeting DA - 15.03.2021 KW - Microstrucrue Design KW - Density-based Thermodynamics PY - 2021 AN - OPUS4-52337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kianinejad, Kaveh A1 - Czediwoda, Fabian A1 - Glatzel, U. A1 - Völkl, R. A1 - Stöhr, B. A1 - Ávila Calderón, Luis A1 - Schriever, Sina A1 - Saliwan Neumann, Romeo A1 - Fedelich, Bernard A1 - Darvishi Kamachali, Reza T1 - Microstructure-based modelling of the anisotropic creep behaviour in additively manufactured INCONEL 718 N2 - The existing gap in the adequate prediction of the microstructure-property relationships remains a significant barrier to the safe application of the additively manufactured materials. This challenge is fundamentally tied to the intricate microstructural defects that emerge during the processing. Systematic microstructure-based modelling can offer solutions to address this bottleneck. In this work, we utilize a crystal plasticity model, developed for gamma''-strengthened Ni-base alloys and calibrated with single crystal tensile and creep tests of Inconel 718. By systematically refining the representative volume element complexity---from equiaxed to elongated grain morphologies, and from unimodal to bimodal orientation and grain size distributions---we demonstrate how each layer of structural realism contributes to the model’s predictive capacity. Creep tests of laser-based powder bed fusion (PBF-LB/M) manufactured samples in three orientations (with the tensile axis parallel, perpendicular, and 45° tilted relative to the building direction) were performed at 650° C, accompanied by electron backscatter secondary diffraction measurements. The results of our simulations reveal that the bimodal grain morphology and crystallographical texture significantly influence the observed creep anisotropy. We show that the elongated grain structure combined with grain boundary sliding plays a major role in the creep response, specifically in tilted specimens. KW - Additive manufactured Ni-base superalloys KW - Creep Anisotropy KW - Crystal plasticity PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646884 DO - https://doi.org/10.1016/j.msea.2025.149029 VL - 945 SP - 1 EP - 15 PB - Elsevier B.V. AN - OPUS4-64688 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Murugan, Jegatheesan T1 - Thermodynamics of Grain Boundary Segregation in Fe-Ni-Cr Alloy Systems N2 - Phase stability in multi-components alloy systems is still largely unknown, especially at the internal interfaces. Grain boundary (co-)segregation is one of the main causes of instability and therefore safety issues in microstructures. In this work, the segregation in FCC Fe-Ni-Cr alloy system, which is the base for several steels, super-alloys and high entropy alloys, is studied. The density-based phase-field model is advanced to compute the segregation of Fe, Ni and Cr at the grain boundary corresponding to the bulk composition. Here the relative density of the grain boundary to the bulk is the mean-field parameter of the model. The necessary thermodynamic parameters of the bulk are obtained from the CALPHAD database. We performed high-throughput screening of the elemental segregation at the grain boundary across the stable bulk compositions at different temperatures (723 K, 1023 K and 1323 K). The results reveal complex enrichment/depletion of each element depending on the alloy composition and temperature. Opposite segregation of Ni and Cr and co-segregation of Ni and Fe is observed for almost all compositions at 723 K, but a changing trend is observed with increasing temperature. We discuss the origin and consequences of these segregation behaviours in the light of magnetic ordering effects. T2 - Materials Science and Engineering (MSE) 2024 CY - Darmstadt, Germany DA - 24.09.2024 KW - Segregation KW - Grain boundaries KW - CALPHAD PY - 2024 AN - OPUS4-62343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kostenko, Yevgen T1 - Harmonizing Viscoplastic Material Model Application within the BMBF-Project “DigitalModelling” of the Platform Material Digital- Basic Idea, General Strategy and Current Status N2 - For decades, Germany stands for excellent cutting-edge research in the field of so-called higher-value constitutive visco-plastic material models and can draw on a large and globally unique pool of material data. However, both the data and the model structure are extremely heterogeneous and sometimes fundamentally different from research center to research center and from industrial partner to industrial partner. To address the heterogeneity in the material model landscape appropriately, an adaptable material model for the specific application and the specific material is required. The relevant parameters for the adapted material model must be identified as objectively and automatically as possible. To achieve a potentially real-time capable implementation, the material model equation system should be abstracted. The “DigitalModeling” project, organized within the German Platform initiative Material Digital, aims to create a standard and an interface that harmonize the scientific and technical development of constitutive, visco-plastic material models, increase their visibility and maximize the productivity of future research funding. This presentation summarizes the basic idea, the strategy behind it as well as the current status of the project, which was started beginning of 2024. T2 - vgbe Workshop with Technical Exhibition Materials & Quality Assurance CY - Bergen, Norway DA - 07.05.2025 KW - Visco-plastic Material Model KW - Simulation Workflows KW - Ontologies KW - Digitalization PY - 2025 AN - OPUS4-64043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Darvishi Kamachali, Reza T1 - Interfacial Spinodals N2 - Despite their finite spatial extent, interfaces can have profound impacts on microstructure properties. This is because of their distinct phase-like properties distinguishing them from the adjacent homogeneous bulk structure. When noticed by solute atoms, interfaces can experience their own chemical phase changes. In this talk, we investigate the constrained states of chemically decomposed phases at interfaces. A density-based theory of interfaces is proposed to describe the confined chemical decomposition at general grain boundaries. Here the grain boundary is viewed as a lesser dense, defected structure with reference to the corresponding bulk structure. Using this picture, the thermodynamic origins of interfacial spinodal phenomena are revealed. We also show that transient interfacial spinodals can be activated over a large alloy composition range, enabling kinetic engineering of interfacial chemistry. T2 - TMS 2021 CY - Online meeting DA - 15.03.2021 KW - Microstrucrue Design KW - Spinodal Decomposition KW - Interfacial Spinodal PY - 2021 AN - OPUS4-52338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Butz, Adam T1 - Detection and prediction of high temperature fatigue crack growth around notches in polycrystalline nickel base alloy N2 - Im Rahmen eines Vorhabens wurden Methoden zur Reduktion des Versuchsaufwandes bei der Modellerstellung für LCF-Lebensdauervorhersage untersucht. Einige dieser Methoden sind hier kurz vorgestellt. N2 - Methods for reducing the experimental effort necessary for the development of LCF life time prediction models were investigated. Some of these methods are briefly presented here. T2 - 4th International Symposium for Fatigue Design and Material Defects CY - Online meeting DA - 26.05.2020 KW - LCF KW - Mechanistic Modelling KW - Fatigue KW - Data Fusion PY - 2020 AN - OPUS4-50904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Darvishi Kamachali, Reza T1 - Grain Boundary Segregation Design using CALPHAD-integrated Phase-Field Modelling N2 - A main source of current challenges in materials science and engineering is the ever-increasing complexity in materials chemistry and processing resulting in complex microstructures, making the assessment of process-microstructure-property-performance relations difficult, even unmanageable. Here the computational materials science is facing the same situation. In this talk, I share a viewpoint that the complexities in chemistry, processing and microstructures can be circumscribed by integrating existing knowledges of bulk thermodynamics and kinetics to the unknown thermodynamics and kinetics of microstructure elements. To this end, I discuss several successful examples on grain boundary segregation engineering how this scientific advance can be conducted. A roadmap is proposed, beginning to form on generalizing the concept of phase diagrams. T2 - ICAMS Advance Discussions: Advanced models for microstructure evolution – process-microstructure-property relationships CY - Bochum, Germany DA - 26.10.2022 KW - Microstructure Design KW - CALPHAD KW - Phase-Field Simulations KW - Machine Learning KW - Phase Diagrams PY - 2022 AN - OPUS4-56348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Creep behavior and microstructural evolution of LPBF 316L N2 - This presentation shows some experimental results of the characterization of the creep behavior of LPBF 316L, which has been poorly studied and understood to date. The presentation includes results regarding the mechanical properties, the initial microstructural state and its evolution under loading, and the damage mechanism. This work was done within the BAM focus area materials project AGIL. As a benchmark to assess the material properties of the LPBF 316L, a conventionally manufactured variant was also tested. T2 - 2nd Workshop on In-situ Monitoring and Microstructure Development in Additive Manufactured alloys at BAM CY - Online Meeting DA - 19.04.2021 KW - 316L KW - Additive Manufacturing KW - Creep behavior PY - 2021 AN - OPUS4-52682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Darvishi Kamachali, Reza T1 - CALPHAD integrated density-based phase diagrams and opening possibilities for grain boundary engineering N2 - Engineering grain boundaries demands a quantitative description of both their segregation and specific phase behavior. Recently I have proposed a density-based model for grain boundary thermodynamics that enables CALPHAD integrated derivation of grain boundary phase diagrams, broadly applied now in studying various alloys. Combining this model with experimental investigations, in this talk, new aspects of interfacial segregation and phase transformation revealed in polycrystalline alloys are discussed. The effect of elastic interaction on grain boundary phase behavior is incorporated. We consider Al alloys and novel high-entropy alloys and discuss a general strategy for grain boundary engineering. T2 - 18th Discussion Meeting on Thermodynamics of Alloys (TOFA) CY - Krakow, Poland DA - 12.09.2022 KW - CALPHAD KW - Microstructure Design KW - Materials Modelling PY - 2022 AN - OPUS4-56044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Saber, Yassin T1 - Fully Automated 3D Printing of Ceramics for Remote and Decentralized Manufacturing N2 - Manufacturing high-performance ceramic components in remote or decentralized environments – such as in the field, on maritime missions or on isolated offshore platforms – requires solutions that are reliable, low-maintenance, and easy to operate. We present a novel end-to-end manufacturing system designed to produce dense, functional, and geometrically complex ceramic parts using Fused Filament Fabrication (FFF) with minimal human intervention. Our system enables the automated production of yttria-stabilized zirconia (YSZ) components by integrating printing, debinding, and sintering into one streamlined process and thus eliminating the need for multiple specialized machines. Our system combines a dual extrusion filament printer with a porous and heat-resistant ceramic print bed. The porous print bed allows for mechanical interlocking of the first printed layers, ensuring adhesion and structural integrity during FFF. YSZ components are printed onto sacrificial polylactide (PLA) rafts, which serve as a temporary foundation. Once printing is finished, a furnace unit is seamlessly lowered, enclosing the green parts for debinding, and sintering. During firing the PLA raft is disintegrated, enabling unconstrained sintering and easy final part removal. In conclusion, our integrated solution enables localized, on demand fabrication of geometrically complex ceramic components in remote environments with increased efficiency and minimal human handling. T2 - Ceramic AM Summit 2025 CY - Berlin, Germany DA - 30.06.2025 KW - Fused Filament Fabrication KW - Ceramics KW - Metalls KW - Process automation PY - 2025 AN - OPUS4-63623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aristia, Gabriela A1 - Bäßler, Ralph A1 - Nofz, Marianne A1 - Sojref, Regine A1 - Kohl, Anka T1 - Short-term exposure tests of ɣ-Al2O3 Sol-gel coating on X20Cr13 in artificial geothermal waters with different pH N2 - The suitability of an Al2O3 coating for corrosion protection on X20Cr13 was evaluated in various artificial geothermal brines, focusing on the influence of different pH (4, 6 and 8) and their chemical compositions on the coating properties. All experiments were performed in the laboratory using autoclaves at 150 ◦C and 1 MPa in deaerated condition for 1 and 7 days. Results showed that the pH of geothermal waters is the most detrimental factor in the transformation of ɣ-Al2O3 and its protective abilities. Delaminations were found in the Coating exposed to geothermal brines with pH 4. FTIR spectra indicated a transformation of ɣ-Al2O3 to boehmite AlOOH after exposure to pH 4 and 6, and bayerite Al(OH)3 was formed after exposure to pH 8. Different Crystal structures of the hydrated Al2O3 also contribute to the stability of the coatings, observed by the SEM- EDX of the surface and cross-section of coatings. This study indicated that ɣ-Al2O3 sol-gel coating presents a promising aspect of corrosion protection in geothermal environment with a neutral pH. KW - Al2O3 KW - Corrosion KW - Coating KW - Martensitic steel PY - 2021 DO - https://doi.org/10.1016/j.geothermics.2021.102193 SN - 0375-6505 VL - 96 SP - 102193 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-52931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Components in CO2-stream, corrosive to Materials to be Used in CC(U)S Applications N2 - CO2 quality specifications are not only a matter of CO2 purity (i.e. CO2 content). The “rest” also matters, in particular contents of reactive impurities affecting material corrosion (and rock alteration). Also chemical reactions in CO2 stream needs to be considered, in particular when combining CO2 streams of different compositions. T2 - WCO Forum at AMPP Annual International Corrosion Conference 2021 CY - Online Meeting DA - 26.04.2021 KW - Carbon capture storage KW - Corrosion PY - 2021 AN - OPUS4-52502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea T1 - Additive manufacturing of ceramics from water-based feedstocks with low binder content N2 - A major challenge in the current ceramic additive manufacturing is the debinding of the printed parts, which is often associated with long process times and limitations in size and wall thickness. Binder jetting, a powder-based AM technology, can in principle generate thick-walled parts with a low amount of organics and with high productivity. However, this technology is often not capable of handling the fine powders required as raw materials for most technical ceramics. In this context, the "layerwise slurry deposition" (LSD-print) has been developed as a layer deposition method using water-based ceramic slurry feedstocks, enabling binder jetting also for advanced ceramic materials. LSD-print thus combines the high-speed printing of binder jetting with the possibility of producing a variety of high-quality technical ceramics. Perspectives and limitations of the LSD-print will be presented, with focus on achieving short debinding cycles and high productivity. T2 - MS&T CY - Pittsburgh, PA, USA DA - 06.10.2024 KW - Additive Manufacturing KW - Ceramic KW - Binder KW - Slurry KW - Water-based PY - 2024 AN - OPUS4-61882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Saber, Yassin T1 - Fully automated and decentralized fused filament fabrication of ceramics for remote applications N2 - Manufacturing of ceramic components 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 ceramic components with complex geometries. 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. This poster presents an innovative approach: 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 parts are printed onto thin sacrificial rafts, which are built using an interface material with the same binder as the ceramic 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 of the ceramic parts and easy removal of the finished parts. In conclusion, our integrated approach enables significant advancements in the fabrication of complex ceramic components in remote environments with increased efficiency and minimal human handling. T2 - yCAM 2024 CY - Tampere, Finnland DA - 06.05.2024 KW - Fused Filament Fabrication PY - 2024 AN - OPUS4-60057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens A1 - Sänger, Johanna A1 - Zocca, Andrea T1 - Continuous layer deposition for the Additive Manufacturing of ceramics by Layerwise Slurry Deposition N2 - Powder bed technologies are amongst the most successful Additive Manufacturing (AM) techniques. The application of these techniques to most ceramics has been difficult so far, because of the challenges related to the deposition of homogeneous powder layers when using fine powders. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method enabling the use of powder bed AM technologies also for advanced ceramic materials. The layerwise slurry deposition consists of the layer-by-layer deposition of a ceramic slurry by means of a doctor blade, in which the slurry is deposited and dried to achieve a highly packed powder. Not only very fine, submicron powders can be processed with low organics, but also the dense powder bed provides excellent support to the parts built. The latest development of this technology shows that it is possible to print ceramic parts in a continuous process by depositing a layer onto a rotating platform, growing a powder bed following a spiral motion. The unique mechanical stability of the layers in LSD-print allows to grow a powder bed several centimeters thick without any lateral support. The continuous layer deposition allows to achieve a productivity more than 10X higher compared to the linear deposition, approaching a build volume of 1 liter/hour. T2 - DKG Jahrestagung 2024 CY - Höhr-Grenzhausen, Germany DA - 09.09.2024 KW - Ceramic KW - Additive manufacturing PY - 2024 AN - OPUS4-61051 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Lena T1 - How will we explore, work, and live on the moon? N2 - 3D-printed landing pads on the moon: Paving the road for large area sintering of lunar regolith. A prerequisite for lunar exploration and beyond is the manufacturing of objects directly on the moon, given the extreme costs involved in the shipping of material from Earth. Looking at processes, raw materials, and energy sources, equipment will certainly have to be brought from Earth at the beginning. Available on the moon are lunar regolith as raw material and the sun as an energy source. One of the first steps towards the establishment of a lunar base is the creation of infrastructure elements, such as roads and landing pads. We’ll introduce you to the ESA-project PAVER that demonstrates the sintering and melting of lunar regolith simulant material to produce large scale 3D printed elements that could be used during human and robotic lunar explorations. T2 - Berlin Science Week CY - Online meeting DA - 09.11.2022 KW - Additive manufacturing KW - Lunar regolith simulant KW - EAC-1A KW - Space exploration PY - 2022 UR - https://www.youtube.com/watch?v=StfLuVhKkUE AN - OPUS4-56377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Corrosion Effects on Materials Considered for CC(U)S Applications N2 - Commercially available carbon steels are suitable for compression and pipelines as long as moisture content and impurities are limited. (water 50 to 100 ppmv, SO2 and NO2 ca. 100 ppmv) Corrosion rates increase with increasing water content. (0.2 – 20 mm/a) Condensation of acids and therefore droplet formation is always possible, even at low water contents. A low SO2 content within the CO2-stream might be more important than a low water content. Cr13-steels showed a general susceptibility to shallow pitting and pitting. So, they seem to be not suitable for CCUS applications. Low alloyed steels showed better corrosion behavior (predictable uniform corrosion). For direct contact with saline aquifer fluids only high alloyed steels shall be used. T2 - EFC Webinar CY - Online Meeting (Chongqing, China) DA - 18.05.2022 KW - Corrosion KW - CO2 quality KW - CO2 KW - CCS KW - CCU KW - Pipeline PY - 2022 AN - OPUS4-54854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph T1 - Electrochemical behaviors of casing steel/mortar interface in CO2 saturated aquifer fluid N2 - To reveal the corrosion resistance of casing steel/mortar interface in CO2 injection condition, sandwich samples were prepared and exposed up to 20 weeks in aquifer fluid under 10 MPa and 60 °C. Cross section analysis revealed the crevice corrosion as main mechanism instead of pitting corrosion despite very high concentration of Cl in NGB. EDS element line scan analysis of the 20-week-exposed metal/mortar coupon showed Chloride distribution, which still not reached the metal/mortar interface, explaining no pitting was observed. It was confirmed that FeCO3 cannot protect the steel surface in CO2 saturated NGB. To verify the protective possibility of passivation happened on casing steel/mortar interface, simulated pore solution was synthesized and used to passivate the steel for 42 days. OCP and EIS confirmed the formation of passive layer. The 42 day passivated layer was broken during the first minute of exposure in CO2 saturated NGB. However, due to high concentration of Ca2+, a new carbonate CaCO3 dense layer was formed, increased the corrosion resistance of steel surface. T2 - EUROCORR 2022 CY - Berlin, Germany DA - 28.08.2022 KW - Corrosion KW - Geothermal KW - CO2 KW - Mortar PY - 2022 AN - OPUS4-55621 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller-Elmau, Johanna T1 - Transparent feedstocks for photon-based addiTve manufacturing technologies for powder processing of ceramics N2 - Photon-based additive manufacturing technologies such as SLA, DLP, LCM, moreover volumetric two-photon-polymerization, Xolography and holographic technologies promise the highest accuracy and dimensional freedom. But to transfer the light through the feedstock it needs sufficient transparency at the used light wavelength. Ceramic particles used for powder processing routes act as scattering sites and therefore hinder the light transmission, unless… The particle size and particle size distribution are chosen small and narrow enough. Particles which are smaller than roughly 1/10th of the light wavelength, mostly nanoparticles around 5nm size, decrease scattering vastly. This turns resins even with homogeneously distributed ceramic weight fraction of up to 80% transparent again. Feedstocks could be prepared for the highly accurate two-photon-polymerization gaining the smallest yttria stabilized zirconia structures with a resolution of 500nm and unique mechanical properties. The same feedstocks could be applied to DLP and LCM as layer-by-layer AM-technologies for bigger parts. Hybridizing both technologies lead to ceramic parts with microscopic accuracy at macroscopic dimensions. The feedstock was even applied to the volumetric Xolography with the highest transparency requirement so far and to versatile and flexible holographic AM. Highly filled nano-particle containing transparent ceramic feedstocks open the way for technical ceramics in high precision manufacturing where the performance and durability and accessibility are increased and created by the unique ceramic properties such as mechanical strength, chemical and thermal resistance and biocompatibility T2 - 2025 International Conference on Additive Manufacturing Technology Frontiers and Applications CY - Xi'an, China DA - 11.04.2025 KW - Tranparent KW - Ceramic KW - Additive manufacturing PY - 2025 AN - OPUS4-65069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zocca, Andrea A1 - Wilbig, Janka A1 - Waske, Anja A1 - Günster, Jens A1 - Widjaja, Martinus Putra A1 - Neumann, C. A1 - Clozel, M. A1 - Meyer, A. A1 - Ding, J. A1 - Zhou, Z. A1 - Tian, X. T1 - Challenges in the Technology Development for Additive Manufacturing in Space N2 - Instead of foreseeing and preparing for all possible scenarios of machine failures, accidents, and other challenges arising in space missions, it appears logical to take advantage of the flexibility of additive manufacturing for “in-space manufacturing” (ISM). Manned missions into space rely on complicated equipment, and their safe operation is a great challenge. Bearing in mind the absolute distance for manned missions to the Moon and Mars, the supply of spare parts for the repair and replacement of lost equipment via shipment from Earth would require too much time. With the high flexibility in design and the ability to manufacture ready-to-use components directly from a computer-aided model, additive manufacturing technologies appear to be extremely attractive in this context. Moreover, appropriate technologies are required for the manufacture of building habitats for extended stays of astronauts on the Moon and Mars, as well as material/feedstock. The capacities for sending equipment and material into space are not only very limited and costly, but also raise concerns regarding environmental issues on Earth. Accordingly, not all materials can be sent from Earth, and strategies for the use of in-situ resources, i.e., in-situ resource utilization (ISRU), are being envisioned. For the manufacturing of both complex parts and equipment, as well as for large infrastructure, appropriate technologies for material processing in space need to be developed. KW - Additive manufacturing KW - Space KW - Process PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549204 DO - https://doi.org/10.1016/j.cjmeam.2022.100018 SN - 2772-6657 VL - 1 IS - 1 SP - 1 EP - 13 PB - Elsevier Ltd. AN - OPUS4-54920 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zocca, Andrea T1 - Additive Manufacturing of advanced ceramics by layerwise slurry deposition and binder jetting (LSD-print) N2 - Powder bed technologies are amongst the most successful Additive Manufacturing (AM) techniques. Powder bed fusion and binder jetting especially are leading AM technologies for metals and polymers, thanks to their high productivity and scalability. The application of these techniques to most ceramics has been difficult so far, because of the challenges related to the deposition of homogeneous powder layers when using fine powders. In this context, the "layerwise slurry deposition" (LSD) has been developed as a layer deposition method which enables the use of powder bed AM technologies also for advanced ceramic materials. The layerwise slurry deposition consists of the layer-by-layer deposition of a ceramic slurry by means of a doctor blade, in which the slurry is deposited and dried to achieve a highly packed powder layer. This offers high flexibility in the ceramic feedstock used, especially concerning material and particle size. The LSD technology can be combined with binder jetting to develop the so-called “LSDprint” process for the additive manufacturing of ceramics. The LSDprint technology combines the high-speed printing of binder jetting with the possibility of producing a variety of high-quality ceramics with properties comparable to those achieved by traditional processing. In this presentation, the LSD process will be introduced and several examples of application ranging from silicate to high-performance ceramics will be shown. Recent developments towards the scale-up and industrialization of this process will be discussed, alongside future perspectives for the multi-material additive manufacturing. T2 - Ceramics in Europe 2022 CY - Krakow, Poland DA - 10.07.2022 KW - Layerwise slurry deposition KW - Laser induced slipcasting KW - Additive Manufacturing KW - Ceramics PY - 2022 AN - OPUS4-55543 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Günster, Jens A1 - Zocca, Andrea T1 - Dense Powder Beds for the Additive Manufacturing of Ceramics N2 - Regarding feedstocks for the additive manufacturing (AM) of ceramics, two features are most critical in classical powder based AM processes: a high particle packing density (typically >50% TD) must be achieved with very fine particles (typically submicron) in order to ensure sufficient sintering activity. Three innovative approaches will be introduced to overcome this problem: 1. Layer wise slurry deposition: The use of water based ceramic slurries as feedstock for the additive manufacture of ceramics has many advantages which are not fully exploit yet. In the layerwise slurry deposition (LSD) process a slurry with no or low organic content is repetitively spread as thin layers on each other by means of a doctor blade. During the deposition, the ceramic particles settle on the previously deposited and dried material to form thin layers with a high packing density (55-60%). The LSD therefore shares aspects both of tape casting and slip casting. The LSD differentiates from the classical powder-based AM layer deposition, which typically achieves with a flowable coarse grained powder a low packing density (35-50%) only, consequently hindering the ability of sintering ceramic parts to full density. The LSD is coupled with the principles of selective laser sintering (SLS) or binder jetting, to generate novel processes which take advantage of the possibility of achieving a highly dense powder-bed. 2. Laser induced slip casting: Contrary to the LSD process, which requires drying of each individual layer, the direct interaction of ceramic slurries with intense laser radiation, for the laser induced slip casting (LIS), is a promising approach for the additive manufacture of voluminous parts. 3. Gas flow assisted powder deposition: By the application of a vacuum pump a gas flow is realized throughout the powder bed. This gas flow stabilizes the powder bed and results into an enhanced flowability and packing density of the powder during layer deposition. The presentation will provide a detailed discussion of potentialities and issues connected to the mentioned technologies and will describe the most recent developments in their application to technical ceramics. T2 - SmatMade 2022 CY - Osaka, Japan DA - 25.10.2022 KW - Additive Manufacturing KW - Advanced ceramics PY - 2022 AN - OPUS4-59886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Yevtushenko, Oleksandra A1 - Le, Quynh Hoa A1 - Bettge, Dirk T1 - Suitability of Metallic Materials in CC(U)S Applications N2 - Carbon Capture Utilization and Storage (CCUS) is a promising technology to reach the target for reduction of CO2 emissions, e.g. from fossil-fuel operated power plants or cement mills. Crucial points for a sustainable and future-proof CCUS procedure are reliability and cost efficiency of the whole process chain, including separation of CO2 from the source, compression of CO2, its subsequent transportation to the injection site and injection into geological formations, e.g. aquifers. Most components that are in contact with CO2-stream consist of steel. Depending on the operating conditions (e.g. temperature, pressure, and CO2-stream composition) specific suitable steels should be used. The compressed CO2-stream is likely to contain process specific impurities; small amounts of SO2 and NO2 in combination with oxygen and water are most harmful. One approach, as currently preferred by pipeline operators, is to clean the CO2-stream to such levels, acceptable for carbon steel, commonly used as pipeline material. Another consideration would be, to use more corrosion resistant alloys for CO2-streams with higher amounts of impurities. Due to the absence of certified benchmarks for upper limits, systematic experiments with impurities in the CO2-stream were carried out reflecting mainly transport and injection conditions. Within the COORAL project (German acronym for “CO2 purity for capture and storage”) levels of impurities in the CO2-stream, being acceptable when using specific steels, were evaluated. Material exposure to dense or multiphase carbon dioxide (CO2) containing specific amounts of water vapor, oxygen (O2) sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) can be a challenge to steels. In some situations, condensation of impurities and reaction products from the CO2 stream can occur. CO2 saturated brine is supposed to rise in the well when the injection process is interrupted. The material selection shall ensure that neither CO2 nor brine or a combination of both will leak out of the inner tubing. This COORAL-work was extended by a follow-up project, called CLUSTER. Here the additional influence of impurities was investigated when merging CO2 streams from different sources, combined within a “so-called” cluster. Results are summarized within the following table regarding suitability for different parts of the process chain. T2 - EUROCORR 2021 CY - Online meeting DA - 20.09.2021 KW - Carbon capture storage KW - Corrosion KW - Steel KW - CCS KW - CCU KW - CO2 PY - 2021 SP - 1 EP - 2 AN - OPUS4-53460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Abel, Andreas T1 - Microstructural and mechanical characterisation of cast Fe-Al-Mo-Ti-B alloys N2 - With the advent of variable renewable energies, long-term energy storage capacities and flexible power generation technologies will be required for reliable grid stability. Hence, power plant technologies and turbomachinery components will continue to be developed and employed for efficient re-conversion of stored energy. With the introduction of new working fluids for higher thermal efficiencies, the working conditions of exposed components and materials will require higher corrosion resistance, but with the same mechanical performance, manufacturability and cost. Intermetallic iron aluminide alloys with their outstanding oxidation and corrosion resistance and good high-temperature properties depict a possible candidate for use in high-temperature structural applications. A quinary Fe-26Al-4Mo-0.5Ti-1B solid-solution alloy with eutectic particle hardening particularly demonstrated competitive mechanical properties compared to high-alloy P92 steels in previous studies. To derive standard material specifications with industrially relevant casting strategies, centrifugal investment-cast Fe-25Al-3.7Mo-0.4Ti-1B was characterised with respect to microstructure, thermophysical properties and mechanical properties under quasi-static tensile and creep loading up to 700 °C. Compared to P92 steel, the alloy demonstrated superior tensile strength above 550 °C and lower creep rates at 650 °C if stresses increase above 170 MPa. At lower temperatures though, the mechanical properties were inferior to P92 steel and related Fe-Al-Mo-Ti-B alloys, which was correlated to large grain sizes, a high tendency to surface and bulk cracking and a pronounced effect of tension-compression asymmetry. In further studies on alloy composition with varying Al, Mo and B concentration, a non-linear relationship of solid-solution hardening with solute Mo concentration was found. In this regard, halving Mo was the most effective measure for reducing brittleness without decreasing strength at room and elevated temperatures. Higher solidification rates and grain refinement down to 30 µm by die casting had a positive effect on ambient tensile strength, but were not achievable by investment casting. Dilatometry and hardness measurements indicated a low thermal vacancy hardening effect which was less sensitive to low-temperature annealing than in B2 FeAl alloys. Although mechanical properties up to 550 °C could be considerably improved by alloy development and processing, ductility at room temperature generally remained below 1%, necessitating substantial design margins for components from Fe-Al-Mo-Ti-B alloys. Despite the inherent limitations of alloy and casting process, the gained insights will help to prioritise future areas of research to mature cost-effective higher-order Fe Al alloys for high-temperature structural applications. KW - Hardness KW - Iron aluminide alloy KW - Micro structure KW - Tensile strength KW - Creep strength PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632810 DO - https://doi.org/10.5445/IR/1000181739 SP - 1 EP - 179 PB - Karlsruher Institut für Technologie (KIT) CY - Karlsruhe AN - OPUS4-63281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Management of Reference Data of Creep of Ni-Based Superalloys Exemplified for CMSX-6 N2 - The identification of process-structure-property relationships of materials inevitably requires the combination of research data from different measurements. Therefore, the concepts related to FAIR (findable, accessible, interoperable, reusable) data handling, increasingly reported in literature, are particularly important in the materials science and engineering domain. However, they have not yet been integrated into a single, overarching methodological framework, particularly for reference data. Here, we introduce such a framework, which covers data generation, documentation, handling, storage, sharing, data search and discovery, retrieval, and usage. Furthermore, we prototypically implement it using a real dataset with creep data of a single-crystal CMSX-6 Ni-based superalloy. The implementation is traceable and permanently accessible through open repositories. The individual elements considered in the framework ensure the functionality and usability of the data and, thus, the adherence to the FAIR principles. In conjunction with this, we present a definition for reference data of materials. Our definition underlines particularly the importance of a comprehensive documentation, e.g., on material provenance, data processing procedures, and the software and hardware used, including software-specific input parameters, as these details enable data users or independent parties to assess the quality of the datasets and to reuse and reproduce the results. Reference data that is managed according to the proposed framework can be used to advance knowledge in the materials science and engineering domain, e.g., by identifying new process-structure-property relations. T2 - The 20th International Conference on Strength of Materials CY - Kyoto, Japan DA - 02.06.2025 KW - NFDI-MatWerk KW - Referenzdaten KW - Data schema KW - Creep PY - 2025 AN - OPUS4-63428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Crafting High-Quality, Reliable, and FAIR Data: From Metadata, Schema and Ontologies to Data Management and Knowledge Transfer N2 - Following the new paradigm of materials development, design and optimization, digitalization is the main goal in materials sciences (MS) 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 (findability, accessibility, interoperability, reusability) 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. In this respect, the motivation for digital transformation in materials sciences stemming from the need to handle the ever-increasing volume and complexity of data will be elaborated on. By embracing digital tools and methodologies, researchers can enhance the efficiency, accuracy, and reproducibility of their work. The benefits of digital transformation in materials sciences are manifold, including improved data management, enhanced collaboration, and accelerated innovation. Being a core component of this transformation, ensuring data reliability and reproducibility is critical for the advancement of the field, enabling researchers to build on each other's work with confidence. Implementing FAIR data principles facilitates this by making data more accessible and usable across different platforms and studies. Furthermore, Semantic Web technologies (SWT) and ontologies play a crucial role in achieving these goals. Ontologies, typically consisting of the T-Box (terminological component) and A-Box (assertional component), provide a structured framework for representing knowledge. This presentation will outline the path of ontology creation and the formal transformation procedure, highlighting the various ontology levels that organize data into meaningful hierarchies. Real-world use cases presented, such as the Tensile Test Ontology (TTO) and the Orowan Demonstrator, illustrate the practical applications of these technologies. These examples will demonstrate how ontologies can be leveraged to standardize data and facilitate interoperability between different systems and research groups. Finally, in this presentation, Ontopanel is introduced, a tool designed to aid in the creation and management of ontologies. Ontopanel simplifies the process of developing and maintaining ontologies, making it accessible to researchers and practitioners in the field. By integrating these technologies and principles, the materials science community can move towards a more digital, interconnected, and efficient future making the knowledge and education on these topics very valuable. T2 - MaRDA MaRCN FAIR Train Workshop CY - Washington, DC, USA DA - 29.07.2024 KW - FAIR KW - Metadata KW - Digitalization KW - Data Interoperability KW - Ontology KW - Education KW - Workshop PY - 2024 AN - OPUS4-60720 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - On an experimentalist's hard search for free volume N2 - This talk was given in honor of Prof. Frans Spaepen, faculty at Harvard University, at the occasion of his Staudinger Lecture and his honorary doctorate degree reception at ETH Zurich. It covers a 10 year long journey of how an experimentalist probes free-volume effects in metallic glasses. T2 - Symposium in honor of Frans Spaepen Honorary Doctorate ETH Zurich CY - Zurich, Switzerland DA - 08.12.2023 KW - Metallic glass KW - Deformation KW - Shear bands PY - 2023 AN - OPUS4-60717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - Probing internal damage in glassy metals N2 - This talk covers strain localization in metallic glasses and how it can be probed non-destructively using acoustic emission and x-ray methods. The results are compared to other methods and contextualized in the context of shear-band dynamics during inhomogeneous flow of metallic glasses. T2 - Seminar Zerstörungsfreie Prüfung TU München 2023 CY - Online meeting DA - 29.06.2023 KW - Metallic glass KW - Deformation KW - Acoustic emission PY - 2023 AN - OPUS4-60718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - Temperature-dependent intermittent plasticity of Nb microcrystals N2 - Intermittent microplasticity via dislocation avalanches indicates scale-invariance, which is a paradigm shift away from traditional bulk deformation. Recently, we have developed an experimental method to trace the spatiotemporal dynamics of correlated dislocation activity (dislocation avalanches) in microcrystals (Phys. Rev. Mat. 2 (2018) 120601; Phys. Rev. Mat. 3 (2019) 080601). Here we exploit the temperature sensitive deformation of bcc metals. A marked change of the slip-size distribution is observed in the studied microcrystals, with increasingly small event-sizes dominating with decreasing temperature. This shows how a reduction in thermal energy increasingly suppresses the length-scale of dislocation avalanches, indicating how long-range correlations become gradually limited to the scale of the lattice. Our results further show that the stress-strain response is composed of strain-increments that are either thermally activated or essentially athermal. Temperature-dependent small-scale testing in combination with state-of-the-art discrete dislocation dynamics (DDD) simulations of Nb microcrystals are used to reveal these insights. T2 - MS&T20 Virtual CY - Online meeting DA - 02.11.2020 KW - Microcrystals PY - 2020 AN - OPUS4-60700 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maaß, Robert T1 - Tracing structural dynamics in metallic glasses during cryogenic cycling N2 - Highly unrelaxed structural states of metallic glasses have often advantageous mechanical properties. Since metallic glasses continuously relax with time (age) or inherently are well relaxed after processing, methods to uniformly rejuvenate the material are needed. One approach that has received attention is the so-called cryogenic-cycling method, during which a metallic glass is repeatedly immersed into liquid nitrogen. In some cases, cryogenic cycling is truly efficient in increasing the stored excess enthalpy of metallic glasses, but it does not seem to be universally applicable to all alloys and structural states. The origins for these differences remain unclear due to our limited understanding of the underlying structural evolution. In order to shed more light onto the fundamental structural processes of cryogenic cycling, we pursue in-situ x-ray photon correlation spectroscopy (XPCS) to trace the atomic-scale structural dynamics of a Zr-based metallic glass in two different structural states (ribbon and bulk metallic glass). This method allows calculating the relaxation times as a function of time throughout the thermal cycling. It is found that the investigated glasses exhibit heterogeneous structural dynamics at 300 K, which changes to monotonic aging at 78 K. Cryogenic cycling homogenizes the relaxation time distribution for both structural states. This effect is much more pronounced in the ribbon, which is the only structural state that rejuvenates upon cycling. We furthermore reveal how fast atomic-scale dynamics is correlated with long-time average structural relaxation times irrespective of the state, and that the ribbon exhibits unexpected additional fast atomic-scale relaxation in comparison to the plate material. Overall, a picture emerges that points towards heterogeneities in fictive temperature as a requirement for cryogenic energy storage. T2 - MRS Fall 2020 - Invited Talk CY - Boston, MA, USA DA - 27.11.2020 KW - Relaxation metallic glasses PY - 2020 AN - OPUS4-59542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Management of Reference Data of Creep of Ni-Based Superalloys Exemplified for CMSX-6 N2 - The identification of process-structure-property relationships of materials inevitably requires the combination of research data from different measurements. Therefore, the concepts related to FAIR (findable, accessible, interoperable, reusable) data handling, increasingly reported in literature, are particularly important in the materials science and engineering domain. However, they have not yet been integrated into a single, overarching methodological framework, particularly for reference data. Here, we introduce such a framework, which covers data generation, documentation, handling, storage, sharing, data search and discovery, retrieval, and usage. Furthermore, we prototypically implement it using a real dataset with creep data of a single-crystal CMSX-6 Ni-based superalloy. The implementation is traceable and permanently accessible through open repositories. The individual elements considered in the framework ensure the functionality and usability of the data and, thus, the adherence to the FAIR principles. In conjunction with this, we present a definition for reference data of materials. Our definition underlines particularly the importance of a comprehensive documentation, e.g., on material provenance, data processing procedures, and the software and hardware used, including software-specific input parameters, as these details enable data users or independent parties to assess the quality of the datasets and to reuse and reproduce the results. Reference data that is managed according to the proposed framework can be used to advance knowledge in the materials science and engineering domain, e.g., by identifying new process-structure-property relations. T2 - TMS 2025 Annual Meeting & Exhibition CY - Las Vegas, NV, USA DA - 22.03.2025 KW - Referenzdaten KW - Creep KW - Data schema KW - NFDI-MatWerk PY - 2025 AN - OPUS4-62849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Wallis, Theophilus T1 - Density-Based Phase-Field Modeling of Grain Boundary Segregation and Structural Transitions N2 - Polycrystalline materials are central to everyday engineering applications and technological advancements. The mechanical and functional properties of these materials can be influenced either negatively or positively by the presence of grain boundaries (GBs). These properties are interconnected with the structure, chemistry, or a combination of both (referred to as chemo-structure) at the GB. Therefore, an in-depth understanding of GBs, and their associated phenomena is key to tuning these materials properties for desired applications. Nevertheless, the intricate and unique characteristics of GBs impose constraints on their general descriptions in existing models designed for studying and understanding them. In this dissertation, a comprehensive tool, the CALPHAD-integrated density-based phase-field (DPF) model \cite{darvishikamachali2020model}, that harnesses atomic-scale GB characteristics, is employed and extended to reveal a deeper understanding of the GB structure, chemistry, chemo-structural coupling and their potential contributions to GB phenomena such as GB structural (and/or chemo-structural) transitions and liquid metal embrittlement. Although GBs possess distinctive crystallographic properties that render them unique and individualistic, it is important to note that they cannot exist independently; rather, they are made of the same constituents as the corresponding bulk material. To this end, the DPF model uses a continuous atomic density field ($\rho$), derived from atomistic simulations, to characterize the GB with reference to its corresponding homogeneous bulk (grain interior). This perspective allows the DPF model to approximate the GB free energy functional based on available bulk thermodynamic data. The DPF model has been utilized to investigate a variety of systems, form unary to multi-component systems \cite{kamachali2024giant,darvishikamachali2020model,darvishikamachali2020segregation,wang2021density,li2020grain,wang2021incorporating,zhou2021spinodal}. Among several novelties in the elucidation of the thermodynamics and kinetics of GBs, the DPF model has shown that GBs can have their own miscibility gap. It further reveals a temporal co-evolution of low and high segregation levels at the GB, which can act as precursor states for the formation of new phases \cite{kwiatkowskidasilva2018phase, kwiatkowskidasilva2019thermodynamics}. In the recent publication on Fe-Mn \cite{darvishikamachali2020segregation} and in various other works \cite{kamachali2024giant,darvishikamachali2020model,darvishikamachali2020segregation,wang2021density,li2020grain,wang2021incorporating,zhou2021spinodal, ikeda2023segregation, ahmadian2023interstitial} of the DPF model, the variation of atomic density field was allowed normal to the GB plane. At the GB plane, the in-plane GB density $\rho^{GB}$ was treated as a constant average value, representing its intrinsic dependence on the GB nature and misorientation. Although this assumption provides a useful simplification in studying GB phenomena, it does have the drawback of overlooking the significance of the in-plane structure variation. This seems to be particularly central in the view of experimental observations that confirm relatively stable grain boundary composition fluctuation \cite{darvishikamachali2020segregation}. In this thesis, the significance and impact of the atomic structure of GBs on their thermodynamics is investigated. This is achieved in two ways: On one hand, by extending the CALPHAD-integrated density-based free energy functional to account for structural degrees of freedom of GBs, and on the other hand, by deducing and linking density-related GB properties to the GB structure through the results of atomistic simulation of the GBs. Naturally, the structure (atomic density) within the GB plane fluctuates. This variation may also be linked to changes in composition due to solute segregation at the GB. While the fact that the GB structure can undergo transitions (referred to as complexions) \cite{frolov2015segregation, cantwell2020grain, cantwell2014grain} is not entirely new, the quantitative measurements of co-existing GB phases are scarce. Recently, instances were reported where the coexistence of two in-plane GB phases was revealed through the application of high-resolution transmission electron microscopy and atomistic simulation \cite{frommeyer2022dual, meiners2020observations}. To this end, the potential of GB structural variation within the DPF model is introduced in this thesis, where the GB in-plane density $\rho^{GB}$ is described as a field, that can vary both in time and space. This extension enables the in-plane GB density $\rho^{GB}$ to evolve and exhibit two distinct low-energy states, denoted as $\rho^{GB} = \rho_1$ and $\rho^{GB} = \rho_2$, where $\rho_2 > \rho_1$. Separating these two structural states is an in-plane line defect. This way, the model allows the studies of the co-evolution between the chemical and structural states of the GB. As a proof of concept and benchmark study, the extended-DPF model is implemented for studying Fe-Mn system. The results show that the GB structure's capacity to respond to chemical variations, as incorporated in the DPF model, enhances the Mn segregation transition at the GB, even in the absence of any alterations to the GB structure. When the GB structure undergo changes (or is non-uniform), the model reveals a coupling between the GB structure and chemical evolution. The ability of the GB structure to change allows the coexistence of spinodally formed low- and high-Mn phases within the GB during segregation transition. The acquired equilibrium segregation isotherms provides insight into the range of alloy compositions where these GB phases remain stabilised. Moreover, the observations indicate that the tendency of the GB to undergo a structural transition (change) is associated with the energy of the in-plane line defect, between low- and high-density domains within the GB plane. The extended-DPF model is further applied to Zn-coated advanced high strength steels (Fe-Zn systems), where Zn segregation to the GB is known to cause severe performance degradation due to liquid metal embrittlement \cite{razmpoosh2021pathway, ikeda2022early, bhattacharya2018liquid}. The effect of GB type and its chemo-structural coupling on Zn segregation is investigated. The results showed a sharp Zn segregation that is strongly influenced by the nature of the GB itself, as well as the coupling between its chemistry and structure. Additionally, GB phase diagrams were constructed across a wide range of alloy compositions and temperatures. The impact of the GB type and chemo-structural coupling on the miscibility gap of GBs is discussed. The DPF model's ability to incorporate atomic-scale characteristics into the construction of Gibbs free energies at the mesoscale ensures it retains key physical insights when predicting microstructure properties. To this end, a robust investigation of the model’s parameters and outputs in comparison to atomistic simulations of GBs is presented. This not only serves as a gauge for the models reliability, but also provide a new framework in establishing an atomistically-informed density-based description of GBs. First, by examining a large dataset of GBs in BCC-Fe and -Mo from atomistic simulations, a connection between their discrete atomic structure and the continuous atomic density function $\rho$ is established. This is achieved by a systematic coarse-graining approach wherein an atomsitically-obtained density function (delta function) is substituted with a normalised Gaussian function, so that, a smooth and continuous atomic density profile in real space can be obtained, where the minimum is the average atomic density at the GB plane $\rho^{GB}$. The investigation revealed a linear proportional relationship between the GB excess free volume and $\rho^{GB}$. This correlation simplifies the computation of the excess free volume as the integration over the portion of the density profile where the atomic density is less than one. Furthermore, the GB energies calculated by atomistic simulations revealed a correlation with $\rho^{GB}$ for certain classification of GB types, therefore enhancing the model's predictive accuracy. Concurrently, the atomic-scale characteristics of GBs can be further harnessed in the DPF models by replacing the simple functional form of the potential energy as given in the original DPF model formulation with a material specific interatomic potential (expressed as a function of the atomic density $\rho$) from molecular dynamic simulations. This way, a reliable prediction of the atomic density gradient energy coefficient for mesoscale simulations can be obtained. KW - Grain boundary structure KW - Grain boundary chemistry KW - Density-based phase-field modelling KW - Grain boundary thermodynamics KW - Grain boundary segregation transition PY - 2025 SP - 1 EP - 134 CY - Aachen AN - OPUS4-64455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Semantic Technologies in Action: Integrating Mechanical and Microstructure Data in MSE N2 - Semantic technologies (ST) are a powerful tool for storing, processing, and querying data in a contextualized and interoperable manner. They enable machine-actionable and human-readable knowledge representations essential for advanced data management, retrieval, and reuse. As one of the key factors within the frame of the collaborative project platform MaterialDigital (PMD), the establishment of a virtual material data space and the semantic modeling of hierarchical, process-dependent material data is aimed at to serve as best-practice examples of knowledge representation through ontologies and knowledge graphs. In this presentation, the application of ST to a specific use case from the field of materials sciences and engineering (MSE) is demonstrated: the integration and analysis of data related to a 2000 series age-hardenable aluminum alloy. By semantically representing mechanical and microstructural data obtained from tensile tests and dark-field transmission electron microscopy across various aging times, an expandable knowledge graph was constructed that is aligned with the PMD Core Ontology (PMDco) and enriched through the Tensile Test (TTO) and Precipitate Geometry Ontologies. This semantically integrated dataset enables advanced analytical capabilities via SPARQL queries and reveals microstructure–property relationships consistent with the well-known Orowan mechanism. The approach highlights the potential of semantic data integration to support FAIR data principles and to foster a more data-centric and interoperable research infrastructure in MSE. T2 - MSE Research Data Forum 2025 CY - Siegburg, Germany DA - 08.07.2025 KW - Semantic Data KW - Data Integration KW - Digitalization KW - Data Interoperability PY - 2025 AN - OPUS4-63666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - IUC02: Framework for Curation & Distribution of Reference Datasets (On the example of Creep Data of Ni Based superalloys) N2 - A research data management framework to conceptualize & implement a digital infrastructure for the Generation, Distribution, and Utilization of reference datasets of materials is presented. The documentation of the test data is often incomplete. This concerns, e.g., material’s manufacturing process or chemical composition, or test equipment’s description and its calibration status. Our concept addresses this issue by proposing the implementation of a requirements profile. A crucial part of the concept is to reach a community-agreement on the definition of reference data and on the underlying data schema and vocabulary. In this presentation a general workflow overview and the relevance of selected individual subworkflows is presented. T2 - MSE Research Data Forum 2025 CY - Siegburg, Germany DA - 08.07.2025 KW - NFDI MatWerk KW - Referenzdaten KW - Kriechen PY - 2025 AN - OPUS4-64881 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Management of Reference Data of Creep of Ni Based Superalloys Exemplified for CMSX 6 N2 - Research data management (RDM) framework to conceptualize & implement a digital infrastructure for the Generation, Distribution, and Utilization of reference datasets of materials. Documentation of the test data is often incomplete. This concerns, e.g., material’s manufacturing process or chemical composition, or test equipment’s description and its calibration status. Our concept addresses this issue by proposing the implementation of a requirements profile. A crucial part of the concept is to reach a community-agreement on the definition of reference data and on the underlying data schema and vocabulary. T2 - 2. SupERBO Symposium on Superalloys CY - Bochum, Germany DA - 27.02.2025 KW - NFDI MatWerk KW - Referenzdaten KW - Kriechen PY - 2025 AN - OPUS4-64859 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Platform MaterialDigital (PMD) - Knowledge Representation, Interoperability, Reliability N2 - Through collaboration in the materials science and engineering (MSE) community, the PMD is collectively developing common standards and prototype solutions for data acquisition, structuring, storage, and processing. This comprises the development of architectural, standardized and foundational ontologies and workflows. Demonstrators resulting from these developments provide good practice examples. The PMD Core Ontology (PMDco) was created as an anchor that allows implementation of semantic data integration. It provides a common and expanding vocabulary to represent and share knowledge while enabling efficient collaboration and promoting interoperability between diverse domains. T2 - Kupfer-Symposium 2025 CY - Schwäbisch-Gmünd, Germany DA - 12.11.2025 KW - Semantic Data KW - Data Integration KW - Digitalization KW - Data Interoperability KW - PMD Core Ontology PY - 2025 AN - OPUS4-64708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -