TY - CONF A1 - Miliūtė, Aistė A1 - Bustamante, Joana A1 - Mieller, Björn A1 - Stawski, Tomasz A1 - George, Janine A1 - Knoop, F. T1 - High-quality zirconium vanadate samples for negative thermal expansion (NTE) analysis N2 - Zirconium vanadate (ZrV2O7) is a well-known negative thermal expansion (NTE) material which exhibits significant isotropic contraction over a broad temperature range (~150°C < T < 800°C). The linear thermal expansion coefficient of ZrV2O7 is −7.1×10-6 K-. Therefore, it can be used to create composites with controllable expansion coefficients and prevent destruction by thermal shock. Material characterization, leading to application, requires pure, homogenous samples of high crystallinity via a reliable synthesis route. While there is a selection of described syntheses in the literature, it still needs to be addressed which synthesis route leads to truly pure and homogenous samples. Here, we study the influence of the synthesis methods (solid-state, sol-gel, solvothermal) and their parameters on the sample's purity, crystallinity, and homogeneity. The reproducibility of results and data obtained with scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetric analysis (DSC/TGA) were analyzed extensively. The sol-gel method proves superior to the solid-state method and produces higher-quality samples over varying parameters. Sample purity also plays an important role in NTE micro and macro-scale characterizations that explain the impact of porosity versus structural changes. Moreover, we implement ab-initio-based vibrational computations with partially treated anharmonicity (quasi-harmonic approximation, temperature-dependent effective harmonic potentials) in combination with experimental methods to follow and rationalize the negative thermal expansion in this material, including the influence of the local structure disorder, microstructure, and defects. Khosrovani et al. and Korthuis et al., in a series of diffraction experiments, attributed the thermal contraction of ZrV2O7 to the transverse thermal motion of oxygen atoms in V-O-V linkages. In addition to previous explanations, we hypothesize that local disorder develops in ZrV2O7 crystals during heating. We are working on the experimental ZrV2O7 development and discuss difficulties one might face in the process as well as high-quality sample significance in further investigation. The obtained samples are currently used in the ongoing research of structure analysis and the negative thermal expansion mechanism. T2 - 4th International Symposium on Negative Thermal Expansion and Related Materials (ISNTE-4) CY - Padua, Italy DA - 04.07.2023 KW - NTE KW - Sol-gel KW - Solid-state KW - Ab-initio KW - TDEP PY - 2023 AN - OPUS4-58132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miliūtė, Aistė A1 - Bustamante, Joana A1 - Mieller, Björn A1 - Stawski, Tomasz A1 - George, Janine A1 - Knoop, F. T1 - High-quality zirconium vanadate samples for negative thermal expansion (NTE) analysis N2 - Zirconium vanadate (ZrV2O7) is a well-known negative thermal expansion (NTE) material which exhibits significant isotropic contraction over a broad temperature range (~150°C < T < 800°C). The linear thermal expansion coefficient of ZrV2O7 is −7.1×10-6 K-. Therefore, it can be used to create composites with controllable expansion coefficients and prevent destruction by thermal shock. Material characterization, leading to application, requires pure, homogenous samples of high crystallinity via a reliable synthesis route. While there is a selection of described syntheses in the literature, it still needs to be addressed which synthesis route leads to truly pure and homogenous samples. Here, we study the influence of the synthesis methods (solid-state, sol-gel, solvothermal) and their parameters on the sample's purity, crystallinity, and homogeneity. The reproducibility of results and data obtained with scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetric analysis (DSC/TGA) were analyzed extensively. The sol-gel method proves superior to the solid-state method and produces higher-quality samples over varying parameters. Sample purity also plays an important role in NTE micro and macro-scale characterizations that explain the impact of porosity versus structural changes. Moreover, we implement ab-initio-based vibrational computations with partially treated anharmonicity (quasi-harmonic approximation, temperature-dependent effective harmonic potentials) in combination with experimental methods to follow and rationalize the negative thermal expansion in this material, including the influence of the local structure disorder, microstructure, and defects. Khosrovani et al. and Korthuis et al., in a series of diffraction experiments, attributed the thermal contraction of ZrV2O7 to the transverse thermal motion of oxygen atoms in V-O-V linkages. In addition to previous explanations, we hypothesize that local disorder develops in ZrV2O7 crystals during heating. We are working on the experimental ZrV2O7 development and discuss difficulties one might face in the process as well as high-quality sample significance in further investigation. The obtained samples are currently used in the ongoing research of structure analysis and the negative thermal expansion mechanism. T2 - 16th International conference on materials chemistry (MC16) CY - Dublin, Ireland DA - 03.07.2023 KW - NTE KW - Sol-gel KW - Solid-state KW - Ab-initio KW - TDEP PY - 2023 AN - OPUS4-58134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miliūtė, Aistė A1 - Bustamante, Joana A1 - Mieller, Björn A1 - Stawski, Tomasz A1 - George, Janine A1 - Knoop, F. T1 - High-quality zirconium vanadate samples for negative thermal expansion (NTE) analysis N2 - Zirconium vanadate (ZrV2O7) is a well-known negative thermal expansion (NTE) material which exhibits significant isotropic contraction over a broad temperature range (~150°C < T < 800°C). The linear thermal expansion coefficient of ZrV2O7 is −7.1×10-6 K-1. Therefore, it can be used to create composites with controllable expansion coefficients and prevent destruction by thermal shock. Material characterization, leading to application, requires pure, homogenous samples of high crystallinity via a reliable synthesis route. While there is a selection of described syntheses in the literature, it still needs to be addressed which synthesis route leads to truly pure and homogenous samples. Here, we study the influence of the synthesis methods (solid-state, sol-gel, solvothermal) and their parameters on the sample's purity, crystallinity, and homogeneity. The reproducibility of results and data obtained with scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry, and thermogravimetric analysis (DSC/TGA) were analyzed extensively. The sol-gel method proves superior to the solid-state method and produces higher-quality samples over varying parameters. Sample purity also plays an important role in NTE micro and macro-scale characterizations that explain the impact of porosity versus structural changes. Moreover, we implement ab-initio-based vibrational computations with partially treated anharmonicity (quasi-harmonic approximation, temperature-dependent effective harmonic potentials) in combination with experimental methods to follow and rationalize the negative thermal expansion in this material, including the influence of the local structure disorder, microstructure, and defects. Khosrovani et al. and Korthuis et al., in a series of diffraction experiments, attributed the thermal contraction of ZrV2O7 to the transverse thermal motion of oxygen atoms in V-O-V linkages. In addition to previous explanations, we hypothesize that local disorder develops in ZrV2O7 crystals during heating. We are working on the experimental ZrV2O7 development and discuss difficulties one might face in the process as well as high-quality sample significance in further investigation. The obtained samples are currently used in the ongoing research of structure analysis and the negative thermal expansion mechanism. T2 - TDEP2023: Finite-temperature and anharmonic response properties of solids in theory and practice CY - Linköping, Sweden DA - 21.08.2023 KW - NTE KW - Sol-gel KW - Solid-state KW - Ab-initio KW - TDEP PY - 2023 AN - OPUS4-58135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria A1 - Mohring, W. A1 - Karafiludis, Stephanos A1 - Schneider, M. A1 - Laplanche, G. A1 - Stephan-Scherb, C. T1 - Effect of a mixed atmosphere H2O-O2-SO2 on the oxidation kinetics and phase formation on CrMnFeCoNi and CrCoNi N2 - The high-temperature corrosion behaviors of the equimolar CrCoNi medium- and CrMnFeCoNi high-entropy alloy were studied in a gas atmosphere consisting of a volumetric mixture of 10% H2O, 2% O2, 0.5% SO2, and 87.5% Ar at 800 °C for up to 96 h. Both alloys were initially single-phase fcc structured and showed a mean grain size of ~50 µm and a homogeneous chemical composition. The oxide layer thickness of the Cantor alloy CrMnFeCoNi increased linearly with exposure time while it remained constant at ~1 µm for CrCoNi. A Cr2O3 layer and minor amounts of (Co,Ni)Cr2O4 developed on CrCoNi while three layers were detected on the Cantor alloy. These layers were a thin and continuous chromium rich oxide layer at the oxide/alloy interface, a dense (Mn,Cr)3O4 layer in the center and a thick and porous layer of Mn3O4 and MnSO4 at the gas/oxide interface. Additionally, a few metal sulfides were observed in the CrMnFeCoNi matrix. These results were found to be in reasonable agreement with thermodynamic calculations. T2 - ICHEM 2023 CY - Knoxville, TN, USA DA - 18.06.2023 KW - High entropy alloys KW - Chemically complex alloys KW - Corrosion KW - Mixed gas atmosphere PY - 2023 AN - OPUS4-57776 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Anker, A. S. A1 - Annadurai, V. A1 - Balazs, D. M. A1 - Bienert, Ralf A1 - Bouwman, W. G. A1 - Breßler, Ingo A1 - Breternitz, J. A1 - Brok, E. S. A1 - Bryant, G. A1 - Clulow, A. J. A1 - Crater, E. R. A1 - De Geuser, F. A1 - Del Giudice, A. A1 - Deumer, J. A1 - Disch, S. A1 - Dutt, S. A1 - Frank, K. A1 - Fratini, E. A1 - Garcia, P. R. A. F. A1 - Gilbert, E. P. A1 - Hahn, Marc Benjamin A1 - Hallett, J. A1 - Hohenschutz, M. A1 - Hollamby, M. A1 - Huband, S. A1 - Ilavsky, J. A1 - Jochum, J. K. A1 - Juelsholt, M. A1 - Mansel, B. W. A1 - Penttilä, P. A1 - Pittkowski, R. K. A1 - Portale, G. A1 - Pozzo, L. D. A1 - Rochels, L. A1 - Rosalie, Julian M. A1 - Saloga, Patrick E. J. A1 - Seibt, S. A1 - Smith, A. J. A1 - Smith, G. N. A1 - Spiering, G. A. A1 - Stawski, Tomasz M. A1 - Taché, O. A1 - Thünemann, Andreas A1 - Toth, K. A1 - Whitten, A. E. A1 - Wuttke, J. T1 - The human factor: results of a small-angle scattering data analysis round robin JF - Journal of Applied Crystallography N2 - A round-robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5% and half of the population width entries within 40%. Due to the added complexity of the structure factor, far fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 and 86%, respectively. This round-robin experiment highlights several causes for the discrepancies, for which solutions are proposed. KW - Round Robin KW - Data analysis KW - Small-angle scattering KW - Nanomaterials KW - Interlaboratory comparability KW - Nanostructure quantification KW - Methodology KW - MOUSE PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587091 DO - https://doi.org/10.1107/S1600576723008324 VL - 56 IS - 6 SP - 1618 EP - 1629 PB - International Union of Crystallography (IUCr) AN - OPUS4-58709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Anker, A. S. A1 - Balazs, D. M. A1 - Beyer, F. L. A1 - Bienert, Ralf A1 - Bouwman, W. G. A1 - Breßler, Ingo A1 - Breternitz, J. A1 - Brok, E. S. A1 - Bryant, G. A1 - Clulow, A. J. A1 - Crater, E. R. A1 - De Geuser, F. A1 - Giudice, A. D. A1 - Deumer, J. A1 - Disch, S. A1 - Dutt, S. A1 - Frank, K. A1 - Fratini, E. A1 - Gilbert, E. P. A1 - Hahn, Marc Benjamin A1 - Hallett, J. A1 - Hohenschutz, Max A1 - Hollamby, M. J. A1 - Huband, S. A1 - Ilavsky, J. A1 - Jochum, J. K. A1 - Juelsholt, M. A1 - Mansel, B. W. A1 - Penttilä, P. A1 - Pittkowski, R. K. A1 - Portale, G. A1 - Pozzo, L. D. A1 - Ricardo de Abreu Furtado Garcia, P. A1 - Rochels, L. A1 - Rosalie, Julian M. A1 - Saloga, P. E. J. A1 - Seibt, S. A1 - Smith, A. J. A1 - Smith, G. N. A1 - Annadurai, V. A1 - Spiering, G. A. A1 - Stawski, Tomasz A1 - Taché, O. A1 - Thünemann, Andreas A1 - Toth, K. A1 - Whitten, A. E. A1 - Wuttke, J. T1 - The human factor: results of a small-angle scattering data analysis Round Robin T2 - arXiv.org N2 - A Round Robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions, and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5 % and half of the population width entries within 40 %, respectively. Due to the added complexity of the structure factor, much fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 % and 86 % respectively. This Round Robin experiment highlights several causes for the discrepancies, for which solutions are proposed. KW - Round Robin KW - Sall-angle scattering KW - Nanostructure quantification KW - Nanostructure KW - SAXS KW - MOUSE KW - X-ray scattering KW - Size distribution KW - Nanoparticles PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571342 DO - https://doi.org/10.48550/arXiv.2303.03772 SP - 1 EP - 23 PB - Cornell University CY - New York AN - OPUS4-57134 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis Alexander A1 - Hammerschmidt, T. A1 - Gedsun, A. A1 - Forti, M. A1 - Olbricht, Jürgen A1 - Stotzka, R. A1 - Skrotzki, Birgit A1 - Shakeel, Y. A1 - Hunke, S. A1 - Tsybenko, H. A1 - Aversa, R. A1 - Chmielowski, M. A1 - Hickel, T. T1 - IUC02 Framework for Curation and Distribution of Reference Datasets using Creep Data of Ni-Base Superalloys as an Example N2 - In our current view, reference datasets in the MSE domain represent specific material properties, e.g., structural, mechanical, … characteristics. A reference dataset must fulfill high-quality standards, not only in precision of measurement but also in a comprehensive documentation of material, processing, and testing history (metadata). This Infrastructure Use Case (IUC) aims to develop a framework for generating reference material datasets using creep data of a single crystal Ni-based superalloy as a best practice example. In a community-driven process, we aim to encourage the discussion and establish a framework for the creation and distribution of reference material datasets. In this poster presentation, we highlight our current vision and activities and intend to stimulate the discussion about the topic reference datasets and future collaborations and work. T2 - NFDI-MatWerk Conference CY - Siegburg, Germany DA - 27.06.2023 KW - Referenzdaten KW - Reference data KW - Syngle Crystal alloy KW - Creep KW - Metadata schema PY - 2023 AN - OPUS4-57923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis Alexander A1 - Hammerschmidt, T. A1 - Stotzka, R. A1 - Forti, M. A1 - Olbricht, Jürgen A1 - Skrotzki, Birgit A1 - Lenze, A. A1 - Gedsun, A. A1 - Hickel, Tilmann A1 - Tsybenko, H. A1 - Chmielowski, M. A1 - Hunke, S. A1 - Shakeel, Y. T1 - Demonstration of the Infrastructure Use Case 02: Framework for curation and distribution of reference datasets N2 - In our current view, reference datasets in the MSE domain represent specific material properties, e.g., structural, mechanical, … characteristics. A reference dataset must fulfill high-quality standards, not only in precision of measurement but also in a comprehensive documentation of material, processing, and testing history (metadata). This Infrastructure Use Case (IUC) aims to develop a framework for generating reference material datasets using creep data of a single crystal Ni-based superalloy as a best practice example. In a community-driven process, we aim to encourage the discussion and establish a framework for the creation and distribution of reference material datasets. In this poster presentation, we highlight our current vision and activities and intend to stimulate the discussion about the topic reference datasets and future collaborations and work. T2 - NFDI-MatWerk Conference CY - Siegburg, Germany DA - 27.06.2023 KW - Referenzdaten KW - Reference data KW - Creep KW - Metadata schema KW - Syngle Crystal alloy PY - 2023 AN - OPUS4-57924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fareed, Adnan A1 - Rosalie, Julian M. A1 - Kumar, Sourabh A1 - Kar, S. A1 - Hickel, Tilmann A1 - Fähler, S. A1 - Maaß, Robert T1 - Constrained incipient phase transformation in Ni-Mn-Ga films: A small-scale design challenge JF - Materials & Design N2 - Ni-Mn-Ga shape-memory alloys are promising candidates for large strain actuation and magnetocaloric cooling devices. In view of potential small-scale applications, we probe here nanomechanically the stress-induced austenite–martensite transition in single crystalline austenitic thin films as a function of temperature. In 0.5 μm thin films, a marked incipient phase transformation to martensite is observed during nanoindentation, leaving behind pockets of residual martensite after unloading. These nanomechanical instabilities occur irrespective of deformation rate and temperature, are Weibull distributed, and reveal large spatial variations in transformation stress. In contrast, at a larger film thickness of 2 μm fully reversible transformations occur, and mechanical loading remains entirely smooth. Ab-initio simulations demonstrate how an in-plane constraint can considerably increase the martensitic transformation stress, explaining the thickness-dependent nanomechanical behavior. These findings for a shape-memory Heusler alloy give insights into how reduced dimensions and constraints can lead to unexpectedly large transformation stresses that need to be considered in small-scale actuation design. KW - Shape-memory alloys KW - Nanoindentation KW - Incipient plasticity KW - NiMaGa PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581422 DO - https://doi.org/10.1016/j.matdes.2023.112259 VL - 233 SP - 1 EP - 8 PB - Elsevier B.V. AN - OPUS4-58142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miliūtė, Aistė A1 - George, Janine A1 - Mieller, Björn A1 - Stawski, Tomasz T1 - ZrV2O7 negative thermal expansion (NTE) material N2 - Zirconium vanadate (ZrV2O7) is a well-known negative thermal expansion (NTE) material that exhibits significant isotropic contraction over a broad temperature range (~150°C < T < 800°C). Therefore, it can be used to create composites with controllable expansion coefficients and prevent thermal stress, fatigue, cracking, and deformation at interfaces. We implement interdisciplinary research to analyze such material. We study the influence of the synthesis methods and their parameters on the sample's purity, crystallinity, and homogeneity. Moreover, we implement ab initio-based vibrational computations with partially treated anharmonicity in combination with experimental methods to follow temperature-induced structural changes and rationalize the negative thermal expansion in this material, including the influence of the local structure disorder. T2 - SALSA Make and Measure Conference CY - Berlin, Germany DA - 13.09.2023 KW - NTE KW - Composites KW - TEM PY - 2023 AN - OPUS4-58367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pauw, Brian Richard A1 - Smales, Glen Jacob A1 - Rosalie, Julian T1 - Small-angle Scattering Data Analysis Round Robin: anonymized results, figures and Jupyter notebook N2 - The intent of this round robin was to find out how comparable results from different researchers are, who analyse exactly the same processed, corrected dataset. This zip file contains the anonymized results and the jupyter notebook used to do the data processing, analysis and visualisation. Additionally, TEM images of the samples are included KW - Round Robin KW - Small-angle Scattering KW - Data analysis PY - 2023 DO - https://doi.org/10.5281/zenodo.7509710 PB - Zenodo CY - Geneva AN - OPUS4-56803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zocca, Andrea A1 - Müller, Bernd R. A1 - Laquai, René A1 - Kupsch, Andreas A1 - Wieder, Frank A1 - Benemann, Sigrid A1 - Wilbig, Janka A1 - Günster, Jens A1 - Bruno, Giovanni T1 - Microstructural characterization of AP40 apatite-wollastonite glass-ceramic JF - Ceramics international N2 - The microstructure of an apatite-wollastonite (code name AP40) glass-ceramic is analyzed in this study by combining 2D microscopy, phase analysis, X-ray absorption and synchrotron X-ray refraction computed tomography (XCT and SXRCT, respectively). It is shown that this combination provides a useful toolbox to characterize the global microstructure in a wide scale range, from sub-micrometer to millimeter. The material displays a complex microstructure comprising a glassy matrix with embedded fluorapatite and wollastonite small crystals. In this matrix, large (up to 200 μm) spike-shaped structures are distributed. Such microstructural features are oriented around a central sphere, thereby forming a structure resembling a sea urchin. A unique feature of SXRCT, in contrast to XCT, is that internal interfaces are visualized; this allows one to show the 3D distribution of these urchins with exceptionally good contrast. Furthermore, it is revealed that the spike-shaped structures are not single crystals, but rather composed of sub-micrometric crystals, which are identified as fluorapatite and diopside phases by SEM-EDX analysis. KW - Glass-ceramic KW - X-ray refraction KW - Computed tomography KW - Microstructure PY - 2023 DO - https://doi.org/10.1016/j.ceramint.2022.12.130 SN - 0272-8842 VL - 49 IS - 8 SP - 12672 EP - 12679 PB - Elsevier Science CY - Amsterdam AN - OPUS4-57452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria A1 - Mohring, W. A1 - Karafiludis, Stephanos A1 - Schneider, M. A1 - Haas, S. A1 - Hagen, S. A1 - Glatzel, U. A1 - Laplanche, G. A1 - Stephan-Scherb, C. T1 - Corrosion in the Co-Cr-Fe-Ni high entropy alloy family N2 - While a lage amount of research on high entropy alloys is oriented towards mechanical properties and the microstructural improvement it is also necessary to keep an eye on the environment that potential application materials will be submitted to. The Co-Cr-Fe-Ni based high entropy family has shown great potential over the years of high entropy research and some candidate alloys are chosen for an insight into their corrosion behaviour. Several atmospheres are studied, i.e. O2, H2O, SO2 and a mix thereof in argon as well as synthetic air. Just as for classic alloys, the chromium is the most important element in terms of protection agains further corrosion. The addition of manganese, as in case of the “Cantor alloy” CrMnFeCoNi, overpasses Cr when it comes to oxygen affinity and thus counteracts the layer formation of Cr2O3. Even without Mn, a temperature chosen too high will also affect the formation of the chromium oxide layer and spall it off, annulling its protective potential. We can also observe how trace elements influence the layer formation. These effects and their mechanisms will be discussed for the alloys CrFeNi, CoCrNi, CrMnFeCoNi and variations of Al10Co25Cr8Fe15Ni36Ti6 using a combination of electron microscopy, thermodynamic calculations and x-ray diffraction. T2 - MRS-T International Conference CY - Hsinchu, Taiwan DA - 17.11.2023 KW - Corrosion KW - Scanning electron microscopy KW - Mixed gas atmosphere PY - 2023 AN - OPUS4-58980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Altmann, Korinna A1 - Marzik, Julian T1 - Roving-Alterung und mechanische Eigenschaften N2 - Im statistischen Mittel steht eine Windkraftanlage (WKA) in Deutschland alle 6 Jahre wegen eines Schadens an den Rotorblättern und verursacht Kosten von 20k€-40k€ infolge Ertragsausfall und Reparaturkosten. Bei über 30.000 WKA in Deutschland verursacht dies jährlichen Kosten von 100-200 Mio. €. Zu 70% sind die Ursachen Fertigungsfehler. Diesem Themenkomplex widmet sich FB-5.3 in Kooperation mit FBs der Zerstörungsfreien Prüfung (Abt. 8) schon seit Jahren. Im aktuellen Projekt geht es um einen vorzeitigen Verschleiß der Rotorblätter infolge der Verwendung gealterter Glasfaser-Rovings. (GF). Die Entwicklung moderner Windkraftanlagen hatte in Europa seinen Ursprung in den 90er Jahren. OEMs und GF-Hersteller waren dicht beisammen. Die Globalisierung des Marktes führt heute zu einer weltweiten Verschiffung der GF in feucht-warmen Containern. Je nach Beschaffenheit (Chemie) der Schlichten (Oberflächenbehandlung) von GF können diese stark altern (Hydrolyse-Effekte) und die Festigkeit kann im Bauteil um bis zu 50% abgemindert sein. In einer Kooperation mit der Rotorblattallianz, einem Zusammenschluss der OEMs, Halbzeugherstellern und Forschungsinstituten, wurden schon vor 5 Jahren in einem Forschungsprojekt (FB-5.3; VH 5538) die chemischen Mechanismen der Alterung exemplarisch für eine Glasfaser-Roving-Type aufgeklärt. Im aktuellen Projekt (FB-5.3; VH 5304) wird ein beschleunigtes Alterungsverfahren (erhöhte Temperatur und Feuchte) am Roving im un-impregnierten Zustand entwickelt und die Festigkeit nachfolgend nach Einbettung in eine Epoxid-Harz-Matrix bestimmt. Je nach Alterungszustand zeigt sich eine Abnahme der Zwischenfaserbruchfestigkeit von bis zu 50%. Nicht alle Glasfaser-Roving-Typen zeigen diesen Effekt. Es ist gelungen für OEMs und Halbzeughersteller ein handhabbares Verfahren zur innerbetrieblichen Qualitätssicherung zu entwickeln, da die wenigsten Firmen über komplexe Analyseverfahren, wie an der BAM, verfügen. T2 - Composite United - AG Faserverbund in der Windenergie CY - Braunschweig, Germany DA - 09.05.2023 KW - Faserkunststoffverbunde KW - Windenergie KW - Alterung PY - 2023 AN - OPUS4-58409 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -