TY - CONF A1 - Ávila Calderón, Luis T1 - Low-cycle-fatigue behavior of stainless steel 316L manufactured by laser powder bed fusion N2 - This contribution presents the results of an experimental study on the LCF behavior of an austenitic 316L stainless steel produced by laser powder bed fusion featuring a low defect population, which allows for an improved understanding of the role of other typical aspects of a PBF‑LB microstructure. The LCF tests were performed between room temperature and 600 °C. A hot‑rolled 316L variant was tested as a reference. The mechanical response is characterized by strain-life curves, a Coffin‑Manson‑Basquin fitting, and cyclic deformation curves. The damage and deformation mechanisms are studied with X-ray computed tomography, optical and electron microscopy. The PBF‑LB/M/316L exhibits lower fatigue lives at lower strain amplitudes. The crack propagation is mainly transgranular. The solidification cellular structure seems to be the most relevant underlying microstructural feature determining the cyclic deformation behavior. T2 - TMS 2024 Annual Meeting & Exhibition CY - Orlando, Florida, US DA - 03.03.2024 KW - AGIL KW - Additive Fertigung KW - Mikrostruktur KW - LCF KW - 316L PY - 2024 AN - OPUS4-59782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Han, Ying T1 - High cycle fatigue behavior of alloy EN AW-2618A N2 - The presentation shows the results of high cycle fatigue (HCF) tests from the aluminium alloy EN AW-2618A. This study investigates the mean stress influence in the T61 condition and the effect of overaging. For this purpose, axial HCF tests were carried out at room temperature and different stress ratios (R=-1, R=0.1) as well as with overaged conditions (T61+10h@230°C, T61+1000h@230°C). After completion of the tests, the fracture surfaces were examined to study crack initiation. T2 - The 18th International Conference on Aluminium Alloys CY - Toyama, Japan DA - 04.09.2022 KW - High Cycle Fatigue KW - Aluminium Alloy KW - EN AW-2618A PY - 2022 AN - OPUS4-55865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Skrotzki, Birgit T1 - Brinell-Hardness (HBW 2.5/62.5) of Al-alloy EN AW-2618A after different aging times and temperatures N2 - The dataset contains data from Brinell hardness measurements of Al-alloy EN AW-2618A after aging for different times and temperatures. Aging was either load free or with applied tensile load (creep). KW - Aluminium alloy KW - EN AW-2618A KW - Brinell hardness KW - Aging KW - Creep PY - 2022 UR - https://doi.org/10.5281/zenodo.6787085 UR - https://doi.org/10.5281/zenodo.10396823 DO - https://doi.org/10.5281/zenodo.6787084 PB - Zenodo CY - Geneva AN - OPUS4-55158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd T1 - Adopting FAIR data practices in materials science: Semantic representation of a quantitative precipitation analysis N2 - Many metallic materials gain better mechanical properties through controlled heat treatments. For example, in age-hardenable aluminium alloys, the strengthening mechanism is based on the controlled formation of nanometre-sized precipitates, which represent obstacles to dislocation movement and consequently increase the strength. Precise tuning of the material microstructure is thus crucial for optimal mechanical behaviour under service condition of a component. Therefore, analysis of the microstructure, especially the precipitates, is essential to determine the optimum parameters for the interplay of material and heat treatment. Transmission electron microscopy (TEM) is utilized to identify precipitate types and orientations in the first step. Dark-field imaging (DF-TEM) is often used to image the precipitates and thereafter quantify their relevant dimensions. Often, these evaluations are still performed by manual image analysis, which is very time-consuming and to some extent also poses reproducibility problems. Our work aims at a semantic representation of an automatable digital approach for this material specific characterization method under adaption of FAIR data practices. Based on DF-TEM images of different precipitation states of a wrought aluminium alloy, the modularizable, digital workflow of quantitative analysis of precipitate dimensions is described. The integration of this workflow into a data pipeline concept will also be discussed. Using ontologies, the raw image data, their respective contextual information, and the resulting output data of the quantitative image analysis can be linked in a triplestore. Publishing the digital workflow and the ontologies will ensure data reproducibility. In addition, the semantic structure enables data sharing and reuse for other applications and purposes, demonstrating interoperability. T2 - FEMS EUROMAT 2023 CY - Frankfurt a. M., Germany DA - 03.09.2023 KW - Semantic Representation KW - FAIR data management KW - Quantitative Precipitation Analysis KW - Knowledge graph and ontologies PY - 2023 AN - OPUS4-58199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Han, Ying A1 - Radners, J. A1 - von Hartrott, P. A1 - Skrotzki, Birgit T1 - Aluminium high temperature fatigue N2 - The studied aluminium alloy is EN AW-2618A (2618A). It is very widely used for exhaust gas turbo-charger compressor wheels. Due to long operating times, high cycle fatigue (HCF) and material aging under the influence of temperatures up to 230 °C is particularly relevant for the wheels. The wheels are typically milled from round wrought blanks. From such round blanks, different testpieces are extracted and a comprehensive series of HCF tests is conducted at room temperature. The tests investigate the materials fatigue performance in the T61 state for two load-ratios, namely R = -1 and R = 0.1. Additionally, two overaged material states are tested, accounting for the aging process the material undergoes during long operating times at high temperatures. The experimental results are evaluated and compared to each other. Furthermore, the design process of notched specimens is presented. With the notched specimens, it is aimed to quantify the notch sensitivity of the material. Relating thereto, two potential model parameters for the fatigue lifetime model are introduced. Finally, the extended research data management in this project is highlighted and its advantages for sustainable use in material science and engineering applications are shown. N2 - In diesem Projekt wird die Aluminiumlegierung EN AW-2618A (2618A) untersucht, welche sehr verbreitet in Verdichterrädern von Abgasturboladern zum Einsatz kommt. Hochzyklische Ermüdung und Werkstoffalterung bei Temperaturen von bis zu 230 °C ist bei Abgasturboladern aufgrund der langen Einsatzzeiten besonders relevant. Die Verdichterräder werden typischerweise aus geschmiedeten Rohlingen gefräst. Aus entsprechenden Rohlingen werden im Rahmen des Projekts eine Vielzahl von Proben mit unterschiedlichen Geometrien entnommen. Die Proben werden unter verschiedenen Prüfbedingungen in hochzyklischen Ermüdungsversuchen bei Raumtemperatur getestet. Zum einen wird das Ermüdungsverhalten des Werkstoffs im T61-Zustand für die zwei Belastungsverhältnisse R = -1 und R = 0,1 untersucht. Zum anderen werden zwei überalterte Materialzustände getestet. Damit soll dem Alterungsprozess Rechnung getragen werden, den das Material während langer Betriebszeiten bei hohen Temperaturen durchläuft. Die experimentellen Ergebnisse werden evaluiert und miteinander verglichen. Darüber hinaus wird der Entwurfsprozess von gekerbten Probengeometrien dokumentiert. Die gekerbten Proben sollen Aufschluss über die Kerbempfindlichkeit des Werkstoffs geben. In diesem Zusammenhang werden zwei mögliche Modellparameter für das zu entwickelnde Lebensdauermodell vorgestellt. Abschließend wird das erweiterte Forschungsdatenmanagement des Projekts beleuchtet und seine Vorteile für die nachhaltige Nutzung in materialwissenschaftlichen und ingenieurtechnischen Anwendungen aufgezeigt. T2 - FVV Frühjahrstagung 2022 CY - Würzburg, Germany DA - 31.03.2022 KW - EN AW-2618A KW - High cycle fatigue KW - Aluminium alloy PY - 2022 IS - FVV Publikationen Heft R602 SP - 617 EP - 634 PB - Forschungsvereinigung Verbrennungskraftmaschinen (FVV) CY - Frankfurt am Main AN - OPUS4-54622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beygi Nasrabadi, Hossein T1 - Nb and Cr coating the CuNi3SiCr powders for low-power laser-based powder bed fusion processing of copper alloys N2 - The laser-based powder bed fusion (PBF-LB/M) processing of high-density copper components is mainly performed with high laser powers due to the low laser absorption of copper powders [1-2]. Metal coating the copper particles has been investigated in this research as an approach for increasing the laser absorption of the feedstock and processing of highly dense copper alloys with low-power lasers. CuNi3SiCr powders were coated with the thin and uniform metallic shells of Nb (60 ± 10 nm) using a rotating Direct Current Magnetron Sputtering Physical Vapor Deposition (DCMS-PVD) reactor. Using such metal-coated particles, copper parts of 98.14% relative density were printed with the PBF-LB/M parameters of 200 W laser powers, 800 mm/s scanning speed, 55 µm hatch distance, and 25 µm layer thickness. The X-ray computed tomography (XCT), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS) investigations show that partial oxidation of Nb-coated particles is responsible for the development of lack-of-fusion holes between the printed layers. An approach based on the nanoindentation and electron backscattered diffraction (EBSD) measurements was utilized to evaluate the correlation between the crystallographic orientations and mechanical properties of the produced samples. In this approach, arrays of indentations (Fig. 1a) were applied on four planes of the samples trimmed in different directions. The EBSD images of these indentation regions reveal the location of each indent in colored grains of different orientations. Here, a microstructure with columnar grains and a high texture intensity of 9.2 has been observed in the plane perpendicular to the building direction. This plane comprises a mixture of red-, green-, and blue-colored grains, while the measured average hardness (H) and indentation modulus (Er) were increased from red grains to green and blue ones, respectively (Fig. 1b). Eventually, the nanoindentation load-displacement curves of [001], [101], and [111] grains (Fig. 1c) were utilized for modeling the elastoplastic features of the produced samples. T2 - MSE2024 CY - Darmstadt, Germany DA - 24.09.2024 KW - Coating KW - Laser-based powder bed fusion processing KW - Copper PY - 2024 AN - OPUS4-61149 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Beygi Nasrabadi, Hossein A1 - Skrotzki, Birgit T1 - Vickers test ontology (VTO) N2 - Vickers Test Ontology (VTO) has developed for representing the Vickers testing process, testing equipment requirements, test pieces charactristics, and related testing parameters and their measurement procedure according to DIN EN ISO 6507-1 standard. Versions info: V2 developed using BFO+CCO top-level ontologies. Repositories: GitLab: https://gitlab.com/kupferdigital/process-graphs/vickers-hardness-test GitHub: https://github.com/HosseinBeygiNasrabadi/Vickers-Test-Ontology-VTO- MatPortal: https://matportal.org/ontologies/VTO IndustryPortal: https://industryportal.enit.fr/ontologies/VTO KW - Ontology KW - Knowledge graph KW - Data mapping KW - Vickers hardness KW - FAIR data. PY - 2024 UR - https://gitlab.com/kupferdigital/process-graphs/vickers-hardness-test UR - https://github.com/HosseinBeygiNasrabadi/Vickers-Test-Ontology-VTO- UR - https://matportal.org/ontologies/VTO UR - https://industryportal.enit.fr/ontologies/VTO PB - GitLab CY - San Francisco, CA, USA AN - OPUS4-60544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Rosalie, Julian M. A1 - Pauw, Brian R. A1 - Hohenwarter, Anton T1 - Precipitate size evolution in an ultrafine-grained magnesium-manganese alloy N2 - Precipitate size evolution during room temperature high-pressure torsion (HPT) of a Mg-1.35wt.%Mn alloy was studied using scanning transmission electron microscopy (STEM) and Small-/Wide-angle X-ray scattering (SAXS/WAXS). The volume fraction of the nm-scale α-Mn particles increased with applied strain, however small angle X-ray scattering (SAXS) indicated that the majority of manganese remained in solution even after 10 HPT rotations, indicating that the reaction progress is still limited by the diffusivity of Mn. Analysis of the precipitate size distribution determined that the mean particle size did not increase over the course of HPT. This, in combination with the precipitate size distribution suggested that precipitate growth was subject to interfacial rather than diffusional control. KW - Severe plastic deformation KW - High-pressure torsion KW - Ultrafine-grained alloys KW - Magnesium KW - Grain-boundary pinning KW - Precipitate growth KW - Interface control KW - Diffusional control PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653422 DO - https://doi.org/10.48550/arXiv.2601.05619 SP - 1 EP - 15 AN - OPUS4-65342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. A1 - Bock, Robert A1 - Günzel, Stephan A1 - Gesell, Stephan T1 - Monte-Carlo-Analysis of Minimum Burst Requirements for Composite Cylinders for Hydrogen Service N2 - For achieving Net Zero-aims hydrogen is an indispensable component, probably the main component. For the usage of hydrogen, a wide acceptance is necessary, which requires trust in hydrogen based on absence of major incidents resulting from a high safety level. Burst tests stand for a type of testing that is used in every test standard and regulation as one of the key issues for ensuring safety in use. The central role of burst and proof test is grown to historical reasons for steam engines and steel vessels but - with respect for composite pressure vessels (CPVs) - not due an extraordinary depth of outcomes. Its importance results from the relatively simple test process with relatively low costs and gets its importance by running of the different test variations in parallel. In relevant test und production standards (as e. g. ECE R134) the burst test is used in at least 4 different meanings. There is the burst test on a) new CPVs and some others b) for determining the residual strength subsequent to various simulations of ageing effects. Both are performed during the approval process on a pre-series. Then there is c) the batch testing during the CPVs production and finally d) the 100% proof testing, which means to stop the burst test at a certain pressure level. These different aspects of burst tests are analysed and compared with respect to its importance for the resulting safety of the populations of CPVs in service based on experienced test results and Monte-Carlo simulations. As main criterial for this the expected failure rate in a probabilistic meaning is used. This finally ends up with recommendations for relevant RC&S especially with respect to GTR 13. T2 - 9th International Conference on Hydrogen Safety CY - Online meeting DA - 21.09.2021 KW - Hydrogen KW - Burst test KW - Composite pressure vessels KW - Net zero KW - Monte-Carlo-Analysis PY - 2021 SP - 133 EP - 146 PB - IGEM AN - OPUS4-55668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winckelmann, Alexander T1 - Investigation of degradation of the aluminum current collector in lithium-ion batteries by glow-discharge optical emission spectroscopy N2 - Lithium-ion batteries (LIBs) are one technology to overcome the challenges of climate and energy crisis. They are widely used in electric vehicles, consumer electronics, or as storage for renewable energy sources. However, despite innovations in batteries' components like cathode and anode materials, separators, and electrolytes, the aging mechanism related to metallic aluminum current collector degradation causes a significant drop in their performance and prevents the durable use of LIBs. Glow-discharge optical emission spectroscopy (GD-OES) is a powerful method for depth-profiling of batteries' electrode materials. This work investigates aging-induced aluminum deposition on commercial lithium cobalt oxide (LCO) batteries' cathodes. The results illustrate the depth-resolved elemental distribution from the cathode surface to the current collector. An accumulation of aluminum is found on the cathode surface by GD-OES, consistent with results from energy-dispersive X-ray spectroscopy (EDX) combined with focused ion beam (FIB) cutting. In comparison to FIB-EDX, GD-OES allows a fast and manageable depth-profiling. Results from different positions on an aged cathode indicate an inhomogeneous aluminum film growth on the surface. The conclusions from these experiments can lead to a better understanding of the degradation of the aluminum current collector, thus leading to higher lifetimes of LIBs. T2 - Adlershofer Forschungsforum 2022 CY - Berlin, Germany DA - 11.11.2022 KW - Lithium Ion Batteries KW - GD-OES KW - FIB KW - SEM KW - EDX PY - 2022 AN - OPUS4-56246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -