TY - JOUR A1 - Epishin, A. A1 - Fedelich, Bernard A1 - Nolze, Gert A1 - Schriever, Sina A1 - Feldmann, Titus A1 - Farzik Ijaz, M. A1 - Viguier, B. A1 - Poquillon, D. A1 - Le Bouar, Y. A1 - Ruffini, A. A1 - Finel, A. T1 - Creep of single crystals of nickel-based superalloys at ultra-high homologous temperature N2 - The creep behavior of single crystals of the nickel-based superalloy CMSX-4 was investigated at 1288 °C, which is the temperature of the hot isostatic pressing treatment applied to this superalloy in the industry. It was found that at this super-solvus temperature, where no gammaPrime-strengthening occurs, the superalloy is very soft and rapidly deforms under stresses between 4 and 16 MPa. The creep resistance was found to be very anisotropic, e.g., the creep rate of [001] crystals was about 11 times higher than that of a [111] crystal. The specimens of different orientations also showed a very different necking behavior. The reduction of the cross-sectional area psi of [001] crystals reached nearly 100 pct, while for a [111] crystal psi = 62 pct. The EBSD analysis of deformed specimens showed that despite such a large local strain the [001] crystals did not recrystallize, while a less deformed [111] crystal totally recrystallized within the necking zone. The recrystallization degree was found to be correlated with deformation behavior as well as with dwell time at high temperature. From the analysis of the obtained results (creep anisotropy, stress dependence of the creep rate, traces of shear deformation, and TEM observations), it was concluded that the main strain contribution resulted from <01-1>{111} octahedral slip. T2 - 3rd European Conference on Superalloys (‘Eurosuperalloys 2018’) CY - Oxford, UK DA - 9.9.2018 KW - Single-crystal KW - Superalloy KW - Creep KW - Isostatic hot pressing (HIP) PY - 2018 DO - https://doi.org/10.1007/s11661-018-4729-6 SN - 1073-5623 SN - 1543-1940 VL - 49A IS - 9 SP - 3973 EP - 3987 PB - Springer Sciences & Business Media CY - New York, NY AN - OPUS4-45660 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Röhsler, Andreas A1 - Sobol, Oded A1 - Nolze, Gert A1 - Unger, Wolfgang A1 - Böllinghaus, Thomas T1 - Use of time-of-flight secondary ion mass spectrometry for the investigation of hydrogen-induced effects in austenitic steel AISI 304L N2 - During the energy transformation from fossil fuels to renewable energy sources, the use of hydrogen as fuel and energy storage can play a key role. This presents new challenges to industry and the scientific community alike. The storage and transport of hydrogen, which is nowadays mainly realized by austenitic stainless steels, remains problematic, which is due to the degradation of mechanical properties and the possibility of phase transformation by hydrogen diffusion and accumulation. The development of materials and technologies requires a fundamental understanding of these degradation processes. Therefore, studying the behavior of hydrogen in austenitic steel contributes to an understanding of the damage processes, which is crucial for both life assessment and safe use of components in industry and transportation. As one of the few tools that is capable of depicting the distribution of hydrogen in steels, time-of-flight secondary ion mass spectrometry was conducted after electrochemical charging. To obtain further information about the structural composition and cracking behavior, electron-backscattered diffraction and scanning electron microscopy were performed. Gathered data of chemical composition and topography were treated employing data fusion, thus creating a comprehensive portrait of hydrogen-induced effects in the austenite grade AISI 304L. Specimens were electrochemically charged with deuterium instead of hydrogen. This arises from the difficulties to distinguish between artificially charged hydrogen and traces existing in the material or the rest gas in the analysis chamber. Similar diffusion and permeation behavior, as well as solubility, allow nonetheless to draw conclusions from the experiments. T2 - 21st International Conference on Secondary Ion Mass Spectrometry CY - Kraków, Poland DA - 10.09.2017 KW - AISI 304L KW - Hydrogen KW - ToF-SIMS KW - Austenitic stainless steel PY - 2018 DO - https://doi.org/10.1116/1.5013931 SN - 1071-1023 VL - 36 IS - 3 SP - Article 03F103, 1 EP - 6 PB - American Vacuum Society (AVS) AN - OPUS4-44840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Wagner, G. A1 - Saliwan Neumann, Romeo A1 - Skála, R. A1 - Geist, V. T1 - Orientation relationships of carlsbergite in schreibersite and kamacite in the north Chile iron meteorite N2 - The crystallographic orientation of carlsbergite (CrN) in the north Chile meteorite (hexahedrite) was investigated using electron backscatter diffraction and transmission electron microscopy. These studies examined the CrN crystals in the rhabdites (idiomorphic schreibersite) and in kamacite. It was found that the CrN crystals embedded in rhabdite show a number of different orientation relationships with the host crystals. These orientations can be explained based on the lattice dimensions of both coexisting crystalline materials. It was also found that both carlsbergite and kamacite are characterized by a high dislocation density (109 cm–2) while rhabdite is free of dislocations. It is supposed that in spite of the deformed metallic matrix, a general connection between the orientation relation of all the phases involved exists. KW - EBSD KW - Phosphides KW - Carlsbergite KW - Orientation relationship KW - Iron meteorites PY - 2006 DO - https://doi.org/10.1180/0026461067040342 SN - 0026-461x SN - 1471-8022 VL - 70 IS - 4 SP - 373 EP - 382 PB - Mineralogical Society of Great Britain and Ireland CY - London AN - OPUS4-14424 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard A1 - Feldmann, Titus A1 - Haftaoglu, Cetin A1 - Nolze, Gert A1 - Schriever, Sina A1 - Epishin, A. A1 - Camin, B. A1 - Lopez-Galilea, I. A1 - Ruttert, B. A1 - Theisen, W. T1 - Untersuchung des Kriechverhaltens einer Nickelbasis-Superlegierung bei ultrahohen homologen Temperaturen und Anwendung auf das heiß-isostatische Pressen (HIP) N2 - Mit Hilfe des HIP-Verfahrens („Hot Isostatic Pressing“) werden Poren in der einkristallinen Nickel-Basis Superlegierung CMSX-4 kontinuierlich geschrumpft und dadurch die nach der Erstarrung und der Wärmebehandlung vorhandene Porosität stark reduziert. In diesem Beitrag werden experimentelle und numerische Untersuchungen zu den Mechanismen der Porenschrumpfung zusammengefasst. Es zeigt sich, dass das Verformungsverhalten während Kriechversuchen bei der HIP-Temperatur durch Versetzungsgleitung auf oktaedrischen Ebenen dominiert wird. Dagegen zeigen Messungen der Porositätsabnahme und Simulationen des Porenschließens, dass die Kinetik der Porenschrumpfung durch das Phänomen der Leerstellendiffusion zwischen Poren und Kleinwinkelkorngrenzen („Low Angle Boundary“, LAB) bestimmt wird. Im Gegensatz führt die klassische Kristallviskoplastizität zu einer systematischen Überschätzung dieser Kinetik. Der scheinbare Widerspruch lässt sich auflösen, wenn man bedenkt, dass auf der Skala der Poren Versetzungsquellen nicht gleichmäßig verteilt sind, wie in der konventionellen Kristallplastizität implizit angenommen wird. Stattdessen wird in einem weiterführenden Modell davon ausgegangen, das Kleinwinkelkorngrenzen (LABs) als Versetzungsquellen fungieren, während die Scherspannungen sehr stark in der Nähe der Poren lokalisiert sind, was die Emission von Versetzungen deutlich reduziert. T2 - Langzeitverhalten warmfester Stähle und Hochtemperaturwerkstoffe CY - Online meeting DA - 27.11.2020 KW - HIP KW - Superlegierung KW - Kriechen PY - 2020 SN - 978-3-946885-95-5 VL - 2020 SP - 28 EP - 39 PB - Forschungsvereinigung Warmfeste Stähle und Hochtemperaturwerkstoffe AN - OPUS4-51796 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sobol, Oded A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Eliezer, D. A1 - Böllinghaus, Thomas A1 - Unger, Wolfgang T1 - Novel approach to image hydrogen distribution and related phase transformation in duplex stainless steels at the sub-micron scale N2 - The effect of electrochemical charging of hydrogen on the structure of a lean duplex stainless steel LDX 2101® (EN 1.4162, UNS S32101) was examined by both Time-of-Flight secondary ion mass spectrometry and electron back-scatter diffraction. The goal is to correlate hydrogen concentration and induced structural changes. Chemical and structural characterizations were done for the same region at the sample's surface with sub-micron spatial resolution. Regions of interest were varying in size between 50 × 50 μm and 100 × 100 μm. The results show a phase transformation of austenite to mainly a defect-rich BCC and scarcely a HCP phase. The phase transformation occurred in deuterium rich regions in the austenite. KW - Time-of-flight secondary ion mass spectrometry KW - ToF-SIMS KW - Electron backscatter diffraction KW - EBSD KW - Hydrogen-assisted cracking KW - Data fusion KW - Lean duplex stainless steel PY - 2017 DO - https://doi.org/10.1016/j.ijhydene.2017.08.016 SN - 0360-3199 VL - 42 IS - 39 SP - 25114 EP - 25120 AN - OPUS4-42022 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Winkelmann, A. A1 - Britton, T. B. T1 - Constraints on the effective electron energy spectrum in backscatter Kikuchi diffraction N2 - Electron backscatter diffraction (EBSD) is a technique to obtain microcrystallographic information from materials by collecting large-angle Kikuchi patterns in the scanning electron microscope (SEM). An important fundamental question concerns the scattering-angle dependent electron energy distribution, which is relevant for the formation of the Kikuchi diffraction patterns. Here we review the existing experimental data and explore the effective energy spectrum that is operative in the generation of backscatter Kikuchi patterns from silicon. We use a full pattern comparison of experimental data with dynamical electron diffraction simulations. Our energy-dependent cross-correlation based pattern matching approach establishes improved constraints on the effective Kikuchi pattern energy spectrum, which is relevant for high-resolution EBSD pattern simulations and their applications. KW - EBSD KW - Kikuchi pattern KW - Simulation KW - Energy distribution KW - Electron energy PY - 2019 SN - 2469-9950 SN - 2469-9969 VL - 99 IS - 6 SP - 064115-1 EP - 064115-13 PB - AIP AN - OPUS4-47635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Heide, K. T1 - Roaldite in the iron-meteorite São Julião de Moreira N2 - Roaldite – Fe4N – has been identified in the São Julião de Moreira iron meteorite using electron backscatter diffraction (EBSD) and simultaneously acquired energy-dispersive x-ray spectroscopy (EDS). Mean-periodic-number images derived from raw EBSD patterns confirm this phase by an even higher spatial resolution compared to EDS. Roaldite appears in the form of systematically and repetitively aligned plates. Despite the locally heavy plastic deformation, it is shown that the origin of the oriented precipitation of roaldite is linked to the orientation of the kamacite matrix. Roaldite can be considered to be precipitated from kamacite using an inverse Kurdjumov-Sachs (K-S) or Nishiyama-Wassermann (N-W) orientation relationship. A more accurate discrimination is impossible due to the accumulated shock deformation, which blurs the local reference orientation of kamacite. The habit plane of roaldite is found to be {112}R, which is most likely parallel to {120}K of kamacite. Some of the roaldite plates contain two orientation variants which repeatedly alternate. Their misorientation angle is about 12°. KW - Plastic deformation KW - Iron meteorite KW - Corrosion KW - Nitride KW - Orientation relationship PY - 2019 DO - https://doi.org/10.1016/j.chemer.2019.125538 VL - 79 IS - 4 SP - 125538 PB - Elsevier AN - OPUS4-50338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Singh, Shobhit Pratap A1 - Löwe, Peter A1 - Schriever, Sina A1 - Olbricht, Jürgen A1 - Rehmer, Birgit A1 - Nolze, Gert A1 - Skrotzki, Birgit T1 - High-throughput creep evaluation of IN738LC in bending using digital image correlation at 850 °C N2 - High-temperature alloys, when used in structural applications, undergo slow time-dependent deformation known as creep. Assessing creep behavior is critical for estimating the in-service life of these alloys. Conventionally, uniaxial creep tests are widely conducted at elevated temperatures to determine creep rates. In recent years, bending creep of cantilevers, when combined with digital image correlation (DIC), has emerged as a promising high-throughput technique for rapidly estimating creep life. However, the applicability of bending creep above 700 ◦C for high-temperature alloys using DIC has not been fully established. In this work, we compare uniaxial creep rates of the nickel-based superalloy IN738LC with bending creep rates measured at 850 ◦C using high-temperature DIC. The bending creep data show excellent agreement with uniaxial creep results in the stress range of 240–360 MPa. The measured creep xponent, a critical rate-determining parameter, is found to be ~8 for both uniaxial and bending creep, with the rate data scattered within a factor of two. An in-house experimental setup was developed to perform bending creep tests at high temperatures, with strain monitored through DIC. Our results demonstrate that bending creep, combined with DIC, provides a reliable and efficient method for creep testing of high-temperature alloys. Compared to conventional uniaxial creep experiments, this approach requires significantly less time and material, thereby reducing effort, energy, and cost. We anticipate that this technique will serve as a foundation for testing precious high-temperature materials. For instance, in ongoing rapid discoveries of advanced alloys, in-service creep life can be evaluated much faster with reduced material requirements. Moreover, this method holds strong potential for application to high-entropy alloys and additively manufactured alloys designed for demanding high-temperature environments. KW - Digital image correlation KW - Bending creep KW - Nickel-based superalloys KW - High throughput testing KW - High-temperature materials PY - 2025 UR - https://www.sciencedirect.com/science/article/pii/S0921509325017034?via%3Dihub DO - https://doi.org/10.1016/j.msea.2025.149479 VL - 950 SP - 1 EP - 12 PB - Elsevier B.V. AN - OPUS4-64814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano-Munoz, Itziar A1 - Mishurova, Tatiana A1 - Thiede, Tobias A1 - Sprengel, Maximilian A1 - Kromm, Arne A1 - Nadammal, Naresh A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Evans, Alexander A1 - Bruno, Giovanni T1 - The residual stress in as‑built Laser Powder Bed Fusion IN718 alloy as a consequence of the scanning strategy induced microstructure N2 - The effect of two types of scanning strategies on the grain structure and build-up of Residual Stress (RS) has been investigated in an as-built IN718 alloy produced by Laser Powder Bed Fusion (LPBF). The RS state has been investigated by X-ray diffraction techniques. The microstructural characterization was performed principally by Electron Backscatter Diffraction (EBSD), where the application of a post-measurement refinement technique enables small misorientations (< 2°) to be resolved. Kernel average misorientation (KAM) distributions indicate that preferably oriented columnar grains contain higher levels of misorientation, when compared to elongated grains with lower texture. The KAM distributions combined with X-ray diffraction stress maps infer that the increased misorientation is induced via plastic deformation driven by the thermal stresses, acting to self-relieve stress. The possibility of obtaining lower RS states in the build direction as a consequence of the influence of the microstructure should be considered when envisaging scanning strategies aimed at the mitigation of RS. KW - Additive manufacturing KW - LPBF KW - Residual stress KW - Inconel 718 KW - Kernel average misorientation KW - Texture PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511769 DO - https://doi.org/10.1038/s41598-020-71112-9 VL - 10 IS - 1 SP - 14645 AN - OPUS4-51176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Nolze, Gert A1 - Roohbakhshan, Farshad A1 - Fedelich, Bernard A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit T1 - Cyclic operation performance of 9-12% Cr ferritic-martensitic steels part 2: Microstructural evolution during cyclic loading and its representation in a physically-based micromechanical model N2 - The current competitive situation on electricity markets forces conventional power plants into cyclic operation regimes with frequent load shifts and starts/shutdowns. In the present work, the cyclic mechanical behavior of ferritic-martensitic 9-12 % Cr steels under isothermal and thermomechanical loading was investigated for the example of grade P92 material. A continuous softening was observed under all loading conditions. The introduction of hold periods to the applied cycles reduced material lifetime, with most prominent effects at technologically relevant small strain levels. The microstructural characterization reveals a coarsening of the original “martensitic” lath-type microstructure to a structure with polygonal subgrains and reduced dislocation density. The microstructural data forms the input for a physically-based modelling approach. T2 - 45. MPA-Seminar CY - Leinfelden-Echterdingen, Germany DA - 01.10.2019 KW - Tempered Martensite Ferritic Steels KW - P92 KW - TEM KW - EBSD KW - Micromechanical model PY - 2019 SP - 80 EP - 85 PB - MPA (Materialprüfungsanstalt Universität Stuttgart) CY - Stuttgart AN - OPUS4-50052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Saliwan Neumann, Romeo A1 - Reith, F. A1 - Etschmann, B. A1 - Kilburn, M. R. A1 - Brugger, J. T1 - Unravelling the formation histories of placer gold and platinum-group mineral particles from Corrego Bom Successo, Brazil: A window into noble metal cycling N2 - Gold and platinum-group-metals (PGM) are cycled through Earth's environments by interwoven geological, physical, chemical and biological processes leading to the trans/neoformation of metallic particles in placers. The placer deposit at Corrego Bom Successo (CBS, Brazil) is one of the few localities worldwide containing secondary gold- and PGM-particles. Placer gold consists of detrital particles from nearby hydrothermal deposits that were transformed in the surface environment. Processes that have affected these particles include shortdistance transport, chemical de-alloying of the primary Gold silver, and (bio)geochemical dissolution/reprecipitation of Gold leading to the formation of pure, secondary gold and the Dispersion of gold nanoparticles. The latter processes are likely mediated by non-living organic matter (OM) and bacterial biofilms residing on the particles. The biofilms are largely composed of metallophillic β- and γ-Proteobacteria. Abundant mobile gold and platinum nanoparticles were detected in surface waters, suggesting similar mobilities of these metals. Earlier hydrothermal processes have led to the formation of coarsely-crystalline, arborescent dendritic potarite (PdHg). On potarite surfaces, biogeochemical processes have then led to the formation of platinum- and palladium-rich micro-crystalline layers, which make up the botryoidal platinum palladium aggregates. Subsequently potarite was dissolved from the core of many aggregates leaving voids now often filled by secondary anatase (TiO2) containing biophilic elements. The presence of fungal structures associated with the anatase suggests that fungi may have contributed to ist formation. For the first time a primary magmatic PGM-particle comprising a mono-crystalline platinum palladium-alloy with platinum iridium osmium inclusions was described from this locality, finally defining a possible primary source for the PGM mineralisation. In conclusion, the formation of modern-day placer gold- and PGM-particles at CBS began 100s ofmillions of years ago bymagmatic and hydrothermal processes. These provided the metal sources for more recent biogeochemical cycling of PGEs and gold that led to the trans/neoformation of gold- and PGM-particles. KW - Gold KW - Platinum-group-metals KW - Biogeochemical cycling KW - Magmatic and hydrothermal processes KW - Biomineralisation PY - 2019 DO - https://doi.org/10.1016/j.gr.2019.07.003 SN - 1342-937X VL - 76 SP - 246 EP - 259 PB - Elsevier AN - OPUS4-48657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Winkelmann, A. A1 - Britton, T. B. A1 - Nolze, Gert T1 - EBSD Kikuchi Pattern Analysis, Silicon 15kV N2 - Supplementary data and images for Si EBSD pattern analysis as presented in: A. Winkelmann, T.B. Britton, G. Nolze "Constraints on the effective electron energy spectrum in backscatter Kikuchi diffraction", Physical Review B (2019). KW - EBSD KW - Electron energy KW - Energy distribution KW - Kikuchi pattern KW - Simulation PY - 2019 DO - https://doi.org/10.5281/zenodo.2565061 PB - Zenodo CY - Geneva AN - OPUS4-51907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -