TY - CONF A1 - Günster, Jens A1 - Zocca, Andrea T1 - Dense Powder Beds for the Additive Manufacturing of Ceramics N2 - Many of the most successful and precise additive manufacturing (AM) technologies are based on the deposition layer-by-layer of a flowable powder. Since the first pioneering work at the end of the 1980th many developments have been introduced, greatly extending the use of different materials, improving the physical properties of the components built and enhancing the accuracy of the process. Still very important issues remain nowadays, hampering a completely autonomous production of parts and even restricting the freedom of design by means of these technologies. One of the major issues is the low density and stability of the parts during the building process, which implies the need of support structures: The powder bed surrounding the part has an essential role, since it should support the structure during building, until it’s ready for removal. Moreover, the microstructure of the powder bed is a template for the microstructure of the part produced. In this context, the use of submicron ceramic powders is still a challenge. Three approaches for the stabilization and densification of powder beds will be presented: The Layerwise Slurry Deposition process LSD, the gas flow assisted powder deposition and the Laser Induced Slipcasting (LIS) of ceramic powder compacts. T2 - 43rd International Conference and Exposition on Advanced Ceramics and Composites (ICACC 2019) CY - Daytona Beach, FL, USA DA - 27.01.2019 KW - Ceramics KW - Additive Manufacturing PY - 2019 AN - OPUS4-49627 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 - Kiefer, P. A1 - Deubener, J. A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Behrens, H. A1 - Balzer, R. T1 - Density, microhardness and elastic moduli of hydrous soda-lime silicate glasses N2 - The effect of structural water on density, elastic constants and microhardness of water-bearing soda-lime-silica glasses of up to 21.5 mol% total water is studied. T2 - 25th International Congress on Glass (ICG2019) CY - Boston, MA, USA DA - 09.06.2019 KW - Elastic constants KW - Soda-lime-silica glass KW - Water content KW - Microhardness PY - 2019 AN - OPUS4-49537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wallis, Theophilus A1 - Darvishi Kamachali, Reza T1 - Density-based phase field modelling of the interplay between grain boundary segregation transition and structure N2 - Grain boundary (GB) chemical and structural variations can significantly influence materials performance. The former is generally ascribed to the structural gradient between the grain and GB. While GB segregation may be accompanied by chemical and structural variations, clear insights about the GB’s thermodynamic phase behaviour upon coupling between its chemistry and structure is lacking. Using the CALPHAD integrated density-based phase field model, we study the co-evolution of GB’s structure and segregation in Fe-Mn alloys. We found that the GB segregation transition is amplified if its structure can respond to chemical variation. Additionally, the coupling between GB structural and segregation evolution was found to enable co-existence of the spinodally formed low- and high-Mn phases within the GB. In the light of atomistic simulations, we expand on investigating the correlation between the parameters that characterise the GB density map with GB properties. T2 - TMS 2023 CY - San Diego, California, USA DA - 19.03.2023 KW - Grain boundary engineering KW - Density-based phase-field modelling KW - Microstructure design PY - 2023 AN - OPUS4-57970 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 - CONF A1 - Mieller, Björn A1 - Rabe, Torsten T1 - Design and fabrication of ceramic springs N2 - Ceramic springs offer versatile possibilities for load bearing or sensor applications in challenging environments. Although it may appear unexpected, a wide range of spring constants can be implemented by material selection and especially by the design of the spring. Based on a rectangular cross-section of the windings, it is possible to design a spring geometry that generates the desired spring constant simply by choosing appropriate diameter, height, widths, and number of windings. In a recent research project the calculation of helical compression springs made of rectangular steel (German standard DIN 2090) was applied for the design of ceramic springs. A manufacturing technology has been worked out to fabricate such springs from hollow cylinders of several highly dense technical ceramics by milling. Ceramic springs with precise rectangular section, without edge damage, and mean surface roughness smaller than 0.2 µm were produced after parameter optimization. Tolerances of less than 10 µm were achieved regarding spring diameter, height, and width of cross section. It is shown that the calculations outlined in the standard are valid for a variety of ceramic materials as well. Demonstrator springs with a wide range of spring constants have been fabricated, including zirconia springs with 0.02 N/mm, alumina springs with 1 N/mm and Si3N4 springs with 5 N/mm. A reproducibility study of six zirconia springs with a constant of 0.3 N/mm showed a relative difference in spring constants of less than +/- 1 %. This combination of a valid calculation approach for spring geometry and a reliable manufacturing technology allows for purposeful development and fabrication of ceramic springs with precise mechanical properties and superior chemical stability. T2 - EUROMAT 2019 CY - Stockholm, Sweden DA - 01.09.2019 KW - Ceramic spring KW - Hard machining KW - Spring constant PY - 2019 AN - OPUS4-48870 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn A1 - Eddah, Mustapha A1 - Bajer, Evgenia A1 - Markötter, Henning A1 - Kranzmann, Axel T1 - Destructive and non-destructive 3D-characterization of inner metal structures in ceramic packages N2 - Ceramic multilayer packages provide successful solutions for manifold applications in telecommunication, microsystem, and sensor technology. In such packages, three-dimensional circuitry is generated by combination of structured and metallized ceramic layers by means of tape casting and multilayer technology. During development and for quality assurance in manufacturing, characterization of integrity, deformation, and positioning of the inner metal features is necessary. Visualization with high resolution and material contrast is needed. Robot-assisted 3D-materialography is a useful technique to characterize such multimaterial structures. In that, many sections of the specimen are polished and imaged automatically. A three-dimensional representation of the structure is created by digital combination of the image stack. A quasi non-destructive approach is to perform X-ray computer tomography (CT) with different beam energies. The energies are chosen to achieve a good imaging of either the metal features, or the ceramic matrix of the structure. The combination of the respective tomograms results in a high contrast representation of the entire structure. Both methods were tested to characterize Ag and Ag/Pd conductors in a ceramic multilayer package. The results were compared in terms of information content, effort, and applicability of the methods. T2 - 98th DKG Annual Meeting - CERAMICS 2023 CY - Jena, Germany DA - 27.03.2023 KW - Ceramics KW - Synchrotron CT KW - 3D materialography PY - 2023 AN - OPUS4-57268 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Butz, Adam A1 - Fedelich, Bernard A1 - Rehmer, Birgit A1 - Mäde, L. 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 - Goedecke, Caroline A1 - Altmann, Korinna A1 - Bannick, C. G. A1 - Kober, E. A1 - Ricking, M. A1 - Schmitt, T. A1 - Braun, Ulrike T1 - Detection of polymers in treated waste water using TED-GC-MS N2 - The presence of large quantities of plastic waste and its fragmentation in various environmental compartments are an important subject of current research. In the environment, (photo ) oxidation processes and mechanical abrasion lead to the formation of microplastics. However, until now, there are no established quality assurance concepts for the analysis of microplastic (<5 mm) in environmental compartments, including sampling, processing and analysis. The aim of the present work is the development of suitable examination methods and protocols (sampling, sample preparation and detection) to qualify and quantify microplastic in urbane water management systems. At first a fractional filtration system for sampling and the analytical tool, the so-called TED-GC-MS (thermal desorption gas chromatography mass spectrometry) were developed. The TED-GC-MS method is a two-step analytical procedure which consists of a thermal extraction where the sample is annealed and characteristic decomposition products of the polymers are collected on a solid phase. Afterwards these products are analysed using GC-MS. The developed fractional filtration for sampling and the TED-GC-MS for detection were used for quantitative analysis to screen the waste water influent and effluent of a Berlin waste water treatment plant for the most relevant polymers, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and polyamide (PA). The results of the study revealed that the polymeres PE, PS and PP were detected in the effluent, and PE and PS were find in the raw waste water of the sewage treatment plant in Ruhleben, Berlin. Differences in polymer types and amounts were detected at different sampling dates and within different sieve fractions. Much higher amounts of polymers were observed in the raw waste water. The peak areas of the decomposition products, used for quantification of the polymers, were adjusted using so-called response factors since the TED-GC-MS method is more sensitive for PP and PS than for PE. It has been shown that PE is the most dominant polymer in the samples. Comparing the masses of polymers in the effluent and in the raw sewage, a removal of 99 % of the polymers in the water treatment plant can be assumed. These results are consistent with the literature where removal rates between 98-99 % were described. T2 - SETAC Europe CY - Rom, Italy DA - 13.05.2018 KW - Microplastics KW - Thermogravimetry KW - Waste water KW - Chromatography PY - 2018 AN - OPUS4-44968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wang, Bin A1 - Mair, Georg A1 - Gesell, Stephan T1 - Determination of Distribution Function used in MCS on Safety Analysis of Hydrogen Pressure Vessel N2 - The test data of static burst strength and load cycle strength of composite pressure vessels are often described by GAUSSian normal or WEIBULL distribution function to perform safety analyses. The goodness of assumed distribution function plays a significant role in the inferential statistics to predict the population properties by using limited test data. Often, GAUSSian and WEIBULL probability nets are empirical methods used to validate the distribution function; Anderson-Darling and KolmogorovSmirnov tests are the mostly favorable approaches for Goodness of Fit. However, the different approaches used to determine the parameters of distribution function lead mostly to different conclusions for safety assessments. In this study, six different methods are investigated to show the variations on the rates for accepting the composite pressure vessels according to GTR No. 13 life test procedure. The six methods are: a) NormLog based method, b) Least squares regression, c) Weighted least squares regression, d) A linear approach based on good linear unbiased estimators, e) Maximum likelihood estimation and f) The method of moments estimation. In addition, various approaches of ranking function are considered. In the study, Monte Carlo simulations are conducted to generate basic populations based on the distribution functions which are determined using different methods. Then the samples are extracted randomly from a population and evaluated to obtain acceptance rate. Here, the “populations” and “samples” are corresponding to the burst strength or load cycle strength of the pressure vessels made from composite material and a plastic liner (type 4) for the storage of hydrogen. To the end, the results are discussed, and the best reliable methods are proposed. T2 - ICHS2019 Conference CY - Adelaide, Australia DA - 24.09.2019 KW - Monte-Carlo Simulation KW - Distribution function KW - Weibull Distribution PY - 2019 AN - OPUS4-49652 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wang, Bin A1 - Mair, Georg A1 - Gesell, Stephan T1 - Determination of Distribution Function used in MCS on Safety Analysis of Hydrogen Pressure Vessel N2 - The test data of static burst strength and load cycle strength of composite pressure vessels are often described by GAUSSian normal or WEIBULL distribution function to perform safety analyses. The goodness of assumed distribution function plays a significant role in the inferential statistics to predict the population properties by using limited test data. Often, GAUSSian and WEIBULL probability nets are empirical methods used to validate the distribution function; Anderson-Darling and Kolmogorov-Smirnov tests are the mostly favorable approaches for Goodness of Fit. However, the different approaches used to determine the parameters of distribution function lead mostly to different conclusions for safety assessments. In this study, six different methods are investigated to show the variations on the rates for accepting the composite pressure vessels according to GTR No. 13 life test procedure. The six methods are: a) Norm-Log based method, b) Least squares regression, c) Weighted least squares regression, d) A linear approach based on good linear unbiased estimators, e) Maximum likelihood estimation and f) The method of moments estimation. In addition, various approaches of ranking function are considered. In the study, Monte Carlo simulations are conducted to generate basic populations based on the distribution functions which are determined using different methods. Then the samples are extracted randomly from a population and evaluated to obtain acceptance rate. Here, the “populations” and “samples” are corresponding to the burst strength or load cycle strength of the pressure vessels made from composite material and a plastic liner (type 4) for the storage of hydrogen. To the end, the results are discussed, and the best reliable methods are proposed. T2 - ICHS International Conference on Hydrogen Safety) 2019 CY - Adelaide, Australia DA - 24.09.2019 KW - Monte-Carlo Simulation KW - Distribution function KW - Weibull Distribution PY - 2019 SP - 103-1 EP - 103-16 AN - OPUS4-50383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kling, I. C. S. A1 - Pauw, Brian Richard A1 - Agudo Jácome, Leonardo A1 - Archanjo, B. S. A1 - Simão, R. A. T1 - Development and characterization of starch film and the incorporation of silver nanoparticles N2 - Starch is one of the biopolymers being used for bioplastic synthesis. For production, starch can be combined with different plasticizers, starches from different plant sources and even with nanomaterials to improve or to add film properties. The challenge of adding these, e.g. in the form of silver nanoparticles (AgNp) is to determine the concentration so as to avoid impairing the properties of the film, agglomeration or altering the visual characteristics of the film. In this study, a starch film synthesis route and the incorporation of silver nanoparticles has been proposed in order not to alter the properties of the film while maintaining the transparency and a clear colour of the starch film. The results showed that the proposed synthesis route is promising, efficient, reproducible, fast and the film has good mechanical properties. T2 - Semana MetalMat & Painal PEMM 2020 CY - Online meeting DA - 23.11.2020 KW - Biofilm KW - Starch KW - Starch nanoparticle KW - Silver nanoparticle PY - 2020 AN - OPUS4-51828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cornelsen Sampaio Kling, I. A1 - Pauw, Brian Richard A1 - Jacome, Leonardo A. A1 - Archanjo, B. S. A1 - Simão, R. A. T1 - Development and characterization of starch film and the incorporation of silver nanoparticles N2 - Starch is one of the biopolymers being used for bioplastic synthesis. For production, starch can be combined with different plasticizers, starches from different plant sources and even with nanomaterials to improve or to add film properties. The challenge of adding these, e.g. in the form of silver nanoparticles (AgNp) is to determine the concentration so as to avoid impairing the properties of the film, agglomeration or altering the visual characteristics of the film. In this study, a starch film synthesis route and the incorporation of silver nanoparticles has been proposed in order not to alter the properties of the film while maintaining the transparency and a clear colour of the starch film. The results showed that the proposed synthesis route is promising, efficient, reproducible, fast and the film has good mechanical properties. T2 - Semana MetalMat & Painal PEMM 2020 CY - Online meeting DA - 23.11.2020 KW - Biofilm KW - Silver nanoparticle KW - Starch KW - Starch nanoparticle PY - 2020 SP - 1 EP - 2 AN - OPUS4-51940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lemiasheuski, Anton A1 - Bajer, Evgenia A1 - Oder, Gabriele A1 - Göbel, Artur A1 - Hesse, Rene A1 - Bettge, Dirk T1 - Development of an Automated 3D Metallography System (RASI) and its Application in Microstructure Analysis N2 - Many microstructural features exhibit non-trivial geometries, which can only be derived to a limited extent from two-dimensional images. E.g., graphite arrangements in lamellar gray cast iron have complex geometries, and the same is true for additively manufactured materials and three-dimensional conductive path structures. Some can be visualized using tomographic methods, but some cannot be due to weak contrast and/or lack of resolution when analyzing macroscopic objects. Classic metallography can help but must be expanded to the third dimension. The method of reconstructing three-dimensional structures from serial metallographic sections surely is not new. However, the effort required to manually assemble many individual sections into image stacks is very high and stands in the way of frequent application. For this reason, an automated, robot-supported 3D metallography system is being developed at BAM, which carries out the steps of repeated preparation and image acquisition on polished specimen. Preparation includes grinding, polishing and optionally etching of the polished surface. Image acquisition comprises autofocused light microscopic imaging at several magnification levels. The image stacks obtained are then pre-processed, segmented, and converted into 3D models, which in the result appear like microtomographic models, but with high resolution at large volume. Contrasting by classical chemical etching reveals structures that cannot be resolved using tomographic methods. The integration of further imaging and measuring methods into this system is underway. Some examples will be discussed in the presentation. T2 - Euromat 2023 CY - Frankfurt a. M., Germany DA - 04.07.2023 KW - Metallography KW - 3D Reconstruction KW - Roboter KW - Automation KW - Microstructure PY - 2023 AN - OPUS4-58202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisenbart, M. A1 - Bauer, F. A1 - Klotz, U. A1 - Weber, M. A1 - Beygi Nasrabadi, Hossein A1 - Skrotzki, Birgit A1 - Klengel, R. A1 - Steinmeier, L. A1 - Parvez, A. A1 - Hanke, T. A1 - Dziwis, G. A1 - Meissner, R. A1 - Tikana, L. A1 - Heisterkamp, J. 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 - Rabe, Torsten A1 - Schulz, Bärbel A1 - Paulick, C. T1 - Development of ceramic helical springs for sensor applications N2 - At high temperatures and in harsh environments ceramic springs are often superior to metallic ones and allow for innovative solutions. A further application was proposed by using ceramic springs as capacitive force sensor. Lower and upper coil surfaces are coated by electrically conducting layers. Deformation of such spring results in a change of capacity. Sensor application calls for helical springs with rectangular cross-section, a linear stress-strain characteristic over entire deformation range and low manufacturing tolerances relating to inner and outer diameter, coil cross section and spring pitch. Furthermore, complex spring design with integrated connecting elements has to be realized. Alumina, zirconia (Y-TZP) and silicon nitride springs were produced by hard machining starting from sintered hollow cylinders. After external and internal cylindrical grinding the hollow cylinders were filled with hard wax, followed by multi-stage cutting of spring coils with custom-made cutting discs. Finally, hard wax was removed by melting and burnout. Best surface and edge qualities of springs were reached using Y-TZP material and hot isostatic pressed alumina. Y-TZP springs produced with material-specifically selected cutting discs and optimized process parameters show sharp coil edges without spallings and mean roughness values of inner surfaces < 0.2 μm. Manufacturing tolerances of spring diameters, spring pitch, height and width of coil cross section are in the range of ± 10 microns. Good reproducibility of spring geometry by optimized hard machining technology allows for production of Y-TZP springs with spring constants differing less than ± 1 % within a series. According to DIN 2090 spring constant for rectangular coil cross section is proportional to the square of height and width of coil cross section and indirectly proportional to number of active coils and to the cube of the mean spring diameter. Hence, spring constants can be tailored over a range of many orders of magnitude by changing the spring dimensions. Good agreement was reached between calculated target spring constants and measured values on produced springs. Alumina and zirconia springs were characterized relating to deformation behavior under dynamic compression load with various deformation speeds and under static tensile loads over long periods of time. Contrary to alumina springs, a non-linear stress-strain behavior of TZP springs was proved in both test series. It is supposed, that pseudoelasticity caused by stress-induced transformation of tetragonal to monoclinic phase is responsible for this special feature of TZP springs. Therefore, TZP material cannot be used for capacitive spring sensors. T2 - European Ceramic Society Conference (ECerS) CY - Torino, Italy DA - 16.06.2019 KW - Ceramic spring KW - Sensor KW - Spring constant KW - Failure test KW - Microstructure PY - 2019 AN - OPUS4-48610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie A1 - Mieller, Björn A1 - Stargardt, Patrick A1 - Töpfer, Jörg A1 - Moos, Ralf A1 - Rabe, Torsten T1 - Development of textured multilayer thermoelectric generators based on calcium cobaltite N2 - Thermoelectric generators can be used as energy harvesters for sensor applications. Multilayer thermoelectric generators (ML-TEGs) are a promising alternative to conventional π-type generators due to their high filling factor, high capability of automated production and the texturing potential during the production process. Calcium cobaltite is a promising thermoelectric oxide (p-type) with highly anisotropic properties. The following study shows the development of a textured unileg ML-TEG using ceramic multilayer technology. Tape-casting and pressure assisted sintering are applied to fabricate textured calcium cobaltite. Compared to conventional sintering, pressure assisted sintering increases the strength by the factor 10. Thermoelectric properties can be tuned either towards maximum power factor or towards maximum figure of merit depending on the pressure level. As electrical insulation material, a screen-printable glass-ceramic with high resistivity and adapted coefficient of thermal expansion is developed. From various commercial pastes a metallization with low contact resistance is chosen. The unileg ML-TEG is co-fired in one single step. The demonstrators reach 80% of the simulated output power and the power output is highly reproducible between the different demonstrators (99%). These results provide the first proof-of-concept for fabricating co-fired multilayer generators based on textured calcium cobaltite with high power factor, high density, and high strength. T2 - Virtual Conference on Thermoelectrics 2021 (VCT) CY - Online meeting DA - 20.07.2021 KW - Thermoelectrics KW - Multilayertechnik KW - Screen printing PY - 2021 AN - OPUS4-52993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stargardt, Patrick A1 - Junge, P. A1 - Greinacher, M. A1 - Kober, D. A1 - Mieller, Björn T1 - Dielectric properties of plasma sprayed coatings for insulation application N2 - Thermal spraying provides a rapid method for additive deposition of various ceramics as electrical insulation in applications where polymers are not suitable. New applications in complex shaped additive manufactured metal parts are emerging for example in large scale electrical devices. Microstructural and dielectric evaluation of coatings is crucial to the employment of such free-form processes. The properties and microstructure of the plasma sprayed alumina coatings are compared with dense reference samples of the same powder produced by spark plasma sintering (SPS). To obtain dense bulk samples from the coarse alumina powder for spray coating, SPS is used. Samples are fabricated by atmospheric plasma spraying (APS) of commercially available alumina powder (d50 = 33 µm) on copper substrates and by SPS of the same powder. Microstructure and porosity were analyzed by optical microscopy and scanning electron microscopy (SEM). Phase compositions were determined by X-ray diffraction (XRD). Dielectric properties such as DC resistance, dielectric strength, dielectric loss, and relative permittivity were determined according to the standards. The microstructure and dielectric properties of the coating and bulk material are compared to assess whether the coating is suitable for use in electrical insulation application. T2 - Ceramics in Europe 2022 CY - Krakow, Poland DA - 10.07.2022 KW - Dielectric characterization KW - Atmospheric plasma spraying KW - Spark plasma sintering KW - Electrical insulation PY - 2022 AN - OPUS4-55328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröder, Jakob A1 - Heldmann, Alexander A1 - Hofmann, Michael A1 - Evans, Alexander A1 - Petry, Winfried A1 - Bruno, Giovanni T1 - Diffraction and Single-Crystal Elastic Constants of Laser Powder Bed Fused Inconel 718 N2 - In this presentation, the results of the determination of the diffraction and single-crystal elastic constants of laser powder bed fused Inconel 718 are presented. The analysis is based on high-energy synchrotron diffraction experiments performed at the Deutsches Elektronen-Synchrotron. It is shown that the characteristic microstructure of laser powder bed fused Inconel 718 impacts the elastic anisotropy and therefore the diffraction and single-crystal elastic constants. Finally, the consequences on the diffraction-based residual stress determination of laser powder bed fused Inconel 718 are discussed. T2 - AWT-Fachausschuss 13 "Eigenspannungen" CY - Wolfsburg, Germany DA - 19.03.2024 KW - Additive Manufacturing KW - Laser Powder Bed fusion KW - Diffraction KW - In-Situ Testing KW - Diffraction Elastic Constants PY - 2024 AN - OPUS4-59900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröder, Jakob A1 - Evans, Alexander A1 - Heldmann, A. A1 - Hofmann, M. A1 - Polatidis, E. A1 - Čapek, J. A1 - Petry, W. A1 - Serrano-Munoz, Itziar A1 - Bruno, Giovanni T1 - Diffraction and Single-Crystal Elastic Constants of Laser Powder Bed Fused Inconel 718 N2 - Laser powder bed fusion (PBF-LB/M) of metallic alloys is a layer-wise additive manufacturing process that provides significant scope for more efficient designs of components, benefiting performance and weight, leading to efficiency improvements for various sectors of industry. However, to benefit from these design freedoms, knowledge of the high produced induced residual stress and mechanical property anisotropy associated with the unique microstructures is critical. X-ray and neutron diffraction are considered the benchmark for non-destructive characterization of surface and bulk internal residual stress. The latter, characterized by the high penetration power in most engineering alloys, allows for the use of a diffraction angle close to 90° enabling a near cubic sampling volume to be specified. However, the complex microstructures of columnar growth with inherent crystallographic texture typically produced during PBF-LB/M of metallics present significant challenges to the assumptions typically required for time efficient determination of residual stress. These challenges include the selection of an appropriate set of diffraction elastic constants and a representative lattice plane suitable for residual stress analysis. In this contribution, the selection of a suitable lattice plane family for residual stress analysis is explored. Furthermore, the determination of an appropriate set of diffraction and single-crystal elastic constants depending on the underlying microstructure is addressed. In-situ loading experiments have been performed at the Swiss Spallation Neutron Source with the main scope to study the deformation behaviour of laser powder bed fused Inconel 718. Cylindrical tensile bars have been subjected to an increasing mechanical load. At pre-defined steps, neutron diffraction data has been collected. After reaching the yield limit, unloads have been performed to study the accumulation of intergranular strain among various lattice plane families. T2 - 11th European Conference on Residual Stresses CY - Prag, Czech Republic DA - 03.06.2024 KW - Additive Manufacturing KW - Laser Powder Bed fusion KW - Diffraction Elastic Constants KW - Microstructure KW - Electron Backscatter Diffraction PY - 2024 AN - OPUS4-60289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - de Camargo, Andréa A1 - Contreras, A. A1 - Niebergall, R. A1 - Schottner, G. A1 - Kilo, M. A1 - Diegeler, A. A1 - Kempf, S. A1 - Puppe, F. A1 - Arendt, F. A1 - Chen, Y.-F. A1 - Sierka, M. A1 - Limbach, R. A1 - Pan, Z. A1 - Wondraczek, L. A1 - Gogula, S. A1 - Bornhöft, H. A1 - Deubener, J. T1 - Digital infrastructure for accelerated glass development N2 - Glasses stand out by their wide and continuously tunable chemical composition and large variety of unique shaping techniques making them a key component of modern high technologies. Glass development, however, is still often too cost-, time- and energy-intensive. The use of robotic melting systems embedded in an ontology-based digital environment is intended to overcome these problems in future. For this purpose, a robotic high throughput glass melting system is equipped with novel inline sensors for process monitoring, machine learning (ML)-based, adaptive algorithms for process monitoring and optimization, novel tools for high throughput glass analysis and ML-based algorithms for glass design. This includes software tools for data mining as well as property and process modelling. The presentation provides an overview of how all these tools merge into a digital infrastructure and illustrates their usability using examples. All infrastructural parts were developed by a consortium consisting of the Fraunhofer ISC in Würzburg, the Friedrich-Schiller-University Jena (OSIM), the Clausthal University of Technology (INW) and the Federal Institute for Materials Research and Testing (BAM, Division Glasses) as part of a joint project of the German research initiative MaterialDigital. T2 - 97. Glass-Technology Conference CY - Aachen, Germany DA - 27.05.2024 KW - Glass KW - Robotic melting KW - Ontologie KW - Simulation KW - Workflow KW - Data Space KW - Digital Twin PY - 2024 AN - OPUS4-60387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rockenhäuser, Christian A1 - von Hartrott, P. A1 - Metzger, M. A1 - Skrotzki, Birgit T1 - Digital material representation of alloy 2618A for the lifetime assessment of radial compressor wheels N2 - The concept of digital material representation is introduced and the aluminium alloy 2618A is discussed as an example of this concept regarding the simulation of material ageing based on nanoscaled precipitates. T2 - Microscopy Conference 2019 (MC2019) CY - Berlin, Germany DA - 01.09.2019 KW - Alloy 2618A KW - Degradation KW - Coarsening KW - Transmission electron microscopy KW - Digital material representation PY - 2019 AN - OPUS4-48954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rockenhäuser, Christian A1 - von Hartrott, P. A1 - Metzger, M. A1 - Skrotzki, Birgit T1 - Digital material representation of precipitation coarsening in alloy 2618A for the lifetime assessment of radial compressor wheels N2 - The concept of digital material representation is introduced and the aluminium alloy 2618A is discussed as an example of this concept regarding the simulation of material ageing based on nanoscaled precipitates. T2 - Microscopy Conference 2019 (MC2019) CY - Berlin, Germany DA - 01.09.2019 KW - Alloy 2618A KW - Aluminium KW - Digital material representation KW - Transmission electron microscopy KW - Material degradation PY - 2019 SP - 183 EP - 184 AN - OPUS4-48885 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beygi Nasrabadi, Hossein A1 - Skrotzki, Birgit T1 - Digital representation of materials testing data for semantic web analytics: Tensile stress relaxation testing use case N2 - This study aims to represent an approach for transferring the materials testing datasets to the digital schema that meets the prerequisites of the semantic web. As a use case, the tensile stress relaxation testing method was evaluated and the testing datasets for several copper alloys were prepared. The tensile stress relaxation testing ontology (TSRTO) was modeled following the test standard requirements and by utilizing the appropriate upper-level ontologies. Eventually, mapping the testing datasets into the knowledge graph and converting the data-mapped graphs to the machine-readable Resource Description Framework (RDF) schema led to the preparation of the digital version of testing data which can be efficiently queried on the web. T2 - ICMDA 2024: 7th International Conference on Materials Design and Applications CY - Tokyo, Japan  DA - 09.04.2024 KW - Digitalization KW - Tensile stress relaxation KW - Ontology KW - Mechanical testing KW - Semantic web PY - 2024 AN - OPUS4-59979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus A1 - Bayerlein, Bernd A1 - Birkholz, H. T1 - Digital Transformation in Materials Science: Insights from Platform MaterialDigital (PMD), Tensile Test Ontology (TTO), Electronic Lab Notebooks (ELN) N2 - The digital era has led to a significant increase in innovation in scientific research across diverse fields and sectors. Evolution of data-driven methodologies lead to a number of paradigm shifts how data, information, and knowledge is produced, understood, and analyzed. High profile paradigm shifts in the field of materials science (MS) include exploitative usage of computational tools, machine learning algorithms, and high-performance computing, which unlock novel avenues for investigating materials. In these presentations, we highlight prototype solutions developed in the context of the Platform MaterialDigital (PMD) project that addresses digitalization challenges. As part of the Material Digital Initiative, the PMD supports the establishment of a virtual materials data space and a systematic handling of hierarchical processes and materials data using a developed ontological framework as high priority work items. In particular, the mid-level ontology PMDco and its augmentation through application-specific ontologies are illustrated. As part of the conclusion, a discussion encompasses the evolutionary path of the ontological framework, taking into account standardization efforts and the integration of modern AI methodologies such as natural language processing (NLP). Moreover, demonstrators illustrated in these presentations highlight: The integration and interconnection of tools, such as digital workflows and ontologies, Semantic integration of diverse data as proof of concept for semantic interoperability, Improved reproducibility in image processing and analysis, and Seamless data acquisition pipelines supported by an ontological framework. In this context, concepts regarding the application of modern research data management tools, such as electronic laboratory notebooks (ELN) and laboratory information management systems (LIMS), are presented and elaborated on. Furthermore, the growing relevance of a standardized adoption of such technologies in the future landscape of digital initiatives is addressed. This is supposed to provide an additional basis for discussion with respect to possible collaborations. T2 - NIST Seminar Series CY - Gaithersburg, MD, USA DA - 11.06.2024 KW - Semantic Data KW - Plattform Material Digital KW - Digitalization KW - Data Interoperability KW - NIST KW - Tensile Test Ontology KW - Elctronic Lab Notebook PY - 2024 AN - OPUS4-60392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bayerlein, Bernd A1 - Schilling, Markus A1 - Birkholz, Henk T1 - Digital Transformation in Materials Science: Insights From the Platform MaterialDigital (PMD) N2 - The digital era has led to a significant increase in innovation in scientific research across diverse fields and sectors. Evolution of data-driven methodologies lead to a number of paradigm shifts how data, information, and knowledge is produced, understood, and analyzed. High profile paradigm shifts in the field of materials science (MS) include exploitative usage of computational tools, machine learning algorithms, and high-performance computing, which unlock novel avenues for investigating materials. In these presentations, we highlight prototype solutions developed in the context of the Platform MaterialDigital (PMD) project that addresses digitalization challenges. As part of the Material Digital Initiative, the PMD supports the establishment of a virtual materials data space and a systematic handling of hierarchical processes and materials data using a developed ontological framework as high priority work items. In particular, the mid-level ontology PMDco and its augmentation through application-specific ontologies are illustrated. As part of the conclusion, a discussion encompasses the evolutionary path of the ontological framework, taking into account standardization efforts and the integration of modern AI methodologies such as natural language processing (NLP). Moreover, demonstrators illustrated in these presentations highlight: The integration and interconnection of tools, such as digital workflows and ontologies, Semantic integration of diverse data as proof of concept for semantic interoperability, Improved reproducibility in image processing and analysis, and Seamless data acquisition pipelines supported by an ontological framework. In this context, concepts regarding the application of modern research data management tools, such as electronic laboratory notebooks (ELN) and laboratory information management systems (LIMS), are presented and elaborated on. Furthermore, the growing relevance of a standardized adoption of such technologies in the future landscape of digital initiatives is addressed. This is supposed to provide an additional basis for discussion with respect to possible collaborations. T2 - NIST Seminar on Digital Transformation CY - Gaithersburg, MD, USA DA - 11.06.2024 KW - Digital Transformation KW - Research Data Management KW - Ontology KW - Reusability KW - FAIR PY - 2024 AN - OPUS4-60381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruns, Sebastian A1 - Bayerlein, Bernd A1 - Grönewald, Mathias A1 - Kryeziu, Jeonna A1 - Schilling, Markus A1 - Waitelonis, Jörg A1 - Portella, Pedro Dolabella A1 - Durst, Karsten T1 - Digitalizing a lab course for undergraduate students: ELN, ontology, data management N2 - We report about a joint project aiming at the digitalization of a lab course in materials testing. The undergraduate students were asked to prepare samples of a precipitation hardened aluminum alloy and characterize them using hardness and tensile tests. In a first step, we developed the frames for the digital labor notebook using eLabFTW. The primary data and the relevant metadata of each run were saved in a central database and made available for analysis and report issues. The whole set of results produced in a course was made available in the database. This database can be improved and serve as an open repository for data on this specific alloy. The logical frame for the joint project was provided by the PMD Core Ontology (PMDco), a mid-level ontology that enables the representation and description of processes and process chains in an MSE-specific manner, ensuring full traceability of generated data. For the digitalization of this lab course, the tensile test ontology (TTO) was applied which is designed as a module of the PMDco using strongly related semantic concepts. T2 - FEMS EUROMAT 2023 CY - Frankfurt a. M., Germany DA - 03.09.2023 KW - Electronic Lab Notebook KW - FAIR data management KW - Digtial Representation KW - Knowledge graph and ontologies PY - 2023 AN - OPUS4-58207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Roohbakhshan, Farshad A1 - Olbricht, Jürgen A1 - Fedelich, Bernard A1 - Skrotzki, Birgit T1 - Dislocation-based modeling of high temperature deformation and fatigue in P92 ferritic-martensitic steels N2 - The employment of renewable energy resources, which are naturally intermittent, for electricity generation has altered the working conditions of conventional power plants from continuous (baseload) to cyclic or flexible operation. For a long time, 9-12% Cr ferritic-martensitic stainless steels have been widely used in power plants due to their favorable characteristics such as high creep strength at high temperatures and oxidation and corrosion resistance. The components of power plants are subjected to long term cyclic loadings including fatigue and creep-fatigue at high temperatures. As ferritic-martensitic steels are known to exhibit cyclic softening when subjected to such loading scenarios, it is crucial to study the material response in such conditions. Since it is impossible to test the material behavior exactly as the operation conditions of power plants, due to technical difficulties and cost issues, it is necessary to develop physically-based material models that can predict the material behavior in more realistic situations. In recent years, many material models have been proposed to describe the behavior of 9-12% Cr ferritic-martensitic stainless steels, which follow phenomenological or physically-based approaches. Phenomenological models provide a stress-strain relation based on empirical observations although they usually lack physical background. To alleviate this drawback and to allow for more flexibility and wider ranges of strain-rate and temperature, physically-based models are suggested. In this approach, microstructural evolution, dislocation movement and/or kinetics of plastic deformation processes are included. The physically-based models allow for a better extrapolation from the experiment results to other operation conditions and their material constants can be interpreted physically. Compared to the former approach, the material behavior can be described more accurately and flexibly and the number of material constants is less in general. In the presented work, the existing micromechanical models developed for P92 steel are compared and extended to allow for new dislocation-based strengthening/cyclic mechanisms. Their performance is assessed in the light of mechanical test data from creep-fatigue and thermo-mechanical fatigue experiments and detailed characterizations of the microstructure evolution in the fatigued material. T2 - 12th International Fatigue Congress CY - Poitiers, France DA - 27.05.2018 KW - 9-12% Cr ferritic-martensitic steels KW - Cyclic softening KW - Micromechanical model KW - Microstructural evolution KW - P92 steels PY - 2018 AN - OPUS4-47101 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beygi Nasrabadi, Hossein A1 - Chen, Yue A1 - Hanke, T. A1 - von Hartrott, P. A1 - Skrotzki, Birgit T1 - Domain-level ontology formulation based on the Platform Material Digital (PMD) ontology: case study Brinell hardness N2 - A large amount of publicly available data is reproduced every day in the field of materials science, while these kind of material data can have different formats and types like paper-type publications, standards, datasheets or isolated datasets in repositories. However, gathering a specific library from such extensive and diverse material data is always challenging for the materials scientists and engineers, since the time-related limitations are not allowed to fully access the large publicly available databases; search across these disparate databases, manage the large volumes of heterogeneous datasets, and integrate data from multiple sources. To address these challenges and make data findable, accessible, interoperable, and reusable (FAIR), an efficient data management system is necessary to build comprehensive, documented, and connected data spaces in the future. A formal standardized knowledge representation through an ontology can address such problems and make data more available and interoperable between related domains. Ontology can also rich machine processable semantic descriptions that increases the performance of scientific searches. In this regard, the Platform MaterialDigital (PMD) is currently working on developing a high-level ontology for the materials and material related processes. For example, in one of the PMD projects of “KupferDigital”, we will try to develop a data ecosystem for digital materials research based on ontology-based digital representations of copper and copper alloys. As a case study, this paper describes the methodology for ontology development of Brinell hardness, based on PMD core ontology. The methodology we describe includes the following steps; gathering the required domain terminology from different resources like standards (DIN EN ISO 6506-1) and test reports, representing the performance of a standard-conformant hardness test and the treatment of the recorded values up to a “reportable” hardness value for a material, designing the process chain according to the semantic technologies, and developing a domain-level ontology of Brinell hardness based on PMD ontology semantic formalization. Apart the mentioned methodology, some interesting tools and methods were introduced and ontology design challenges and possible solutions for modelling materials and processes were discussed. Furthermore, a dataset from the Brinell hardness measurement of cast copper samples is prepared for testing the query process. T2 - MSE 2022 CY - Darmstadt, Germany DA - 27.09.2022 KW - Copper KW - Materials Science KW - Ontology KW - Platform MaterialDigital (PMD) KW - Brinell hardness PY - 2022 AN - OPUS4-56092 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Kratzig, Andreas A1 - Bettge, Dirk A1 - Kranzmann, Axel A1 - Knauer, S. T1 - Droplet corrosion of CO2 transport pipeline steels N2 - In this work, the focus was set on the corrosion process of condensate as drops on the surface of carbon steels (X52, X70), martensitic steel UNS S41500, and superaustenite UNS 08031 in CO2 atmosphere with impurities at 278 K (to simulate the transportation condition in a buried pipeline). Exposure tests were performed at both normal pressure and high pressure where CO2 is supercritical or in dense phase. The drop, 1 ‑ 10 µL in volume, was prepared by dropping CO2 saturated ultra-pure water onto the surface of steel coupons in a one-liter-autoclave. The CO2 gas stream, simulating the oxyfuel flue gas with varying concentration of impurities (SO2 and O2), was then pumped into the autoclave to observe the condensation and corrosion impacts of impurities. Comparable exposure tests were carried out with the same gas mixture and the same volume of water as vapor to observe the drop formation and the corrosion process that follows. The wettability and stability of drops on the surface of steel coupons in CO2 supercritical/dense phase environment was evaluated additionally by contact angle measurement. T2 - NACE International Annual Corrosion Conference CY - Phoenix, AZ, USA DA - 15.04.2018 KW - CCUS KW - Supercritical/dense phase CO 2 KW - Carbon steels KW - Martensitic steel KW - Superaustenite steel KW - Droplet corrosion PY - 2018 AN - OPUS4-44922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Knauer, S A1 - Kratzig, Andreas A1 - Bettge, Dirk A1 - Kranzmann, Axel T1 - Droplet corrosion of CO2 transport pipeline steels N2 - This work examined the droplet corrosion of CO2 pipeline steels caused by impurities in CO2 supercritical/dense phase at 278 K, simulating the underground transport condition. The wetting properties of carbon steels (X52 and X70) as well as martensitic steel UNS S41500, and superaustenite UNS N08031 were studied by contact angle measurement, revealing reactive wetting behavior of carbon steels. Exposure tests with CO2 saturated water droplet on steel surface showed that the impurities (220 ppmv SO2 and 6700 ppmv O2) diffused into the droplet and then reacted with metal coupons in supercritical/dense phase condition, forming the corrosion product instantly during pumping process. Due to the active wetting behavior, the carbon steels suffered from heavily attack, while negligible corrosion product was observed in cases of martensitic steel UNS S41500 and superaustenite UNS 08031 coupons. Condensation experiments that were carried out on fresh polished coupons in CO2 with 1200 ppmv H2O showed that the formation and aggregation of droplet is dependent on the presence of impurities. Without SO2 and O2, the same concentration of H2O did not cause observable corrosion process after a week of exposure. With 220 ppmv SO2 and 6700 ppmv O2 even low water concentration (5-30 ppmv) still resulted in heterogeneous nucleation and subsequent growth of droplets, leading to corrosive process on carbon steel surface albeit to a lesser extent. T2 - CORROSION 2018 CY - Phoenix, AZ, USA DA - 15.04.2018 KW - CCUS KW - Supercritical/dense phase CO2 KW - Carbon steels KW - Martensitic steel KW - Superaustenite steel KW - Droplet corrosion PY - 2018 SP - Paper 10845, 1 EP - 11 PB - NACE International Publications Division CY - Houston, Texas, USA AN - OPUS4-44798 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Knauer, S. A1 - Kratzig, Andreas A1 - Bettge, Dirk A1 - Kranzmann, Axel T1 - Droplet corrosion of CO2 transport pipeline steels N2 - In this work, the focus was set on the corrosion process of condensate as drops on the surface of carbon steels (X52, X70), martensitic steel UNS S41500, and superaustenite UNS 08031 in CO2 atmosphere with impurities at 278 K (to simulate the transportation condition in a buried pipeline). Exposure tests were performed at both normal pressure and high pressure where CO2 is supercritical or in dense phase. The drop, 1 ‑ 10 µL in volume, was prepared by dropping CO2 saturated ultra-pure water onto the surface of steel coupons in a one-liter-autoclave. The CO2 gas stream, simulating the oxyfuel flue gas with varying concentration of impurities (SO2 and O2), was then pumped into the autoclave to observe the condensation and corrosion impacts of impurities. Comparable exposure tests were carried out with the same gas mixture and the same volume of water as vapor to observe the drop formation and the corrosion process that follows. The wettability and stability of drops on the surface of steel coupons in CO2 supercritical/dense phase environment was evaluated additionally by contact angle measurement. T2 - NACE 2018 CY - Phoenix, Arizona, USA DA - 15.04.2018 KW - Droplet corrosion KW - CCUS KW - Supercritical/dense phase CO2 KW - Carbon steels KW - Martensitic steel KW - Superaustenite steel PY - 2018 AN - OPUS4-44767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Le, Quynh Hoa A1 - Bäßler, Ralph A1 - Kratzig, Andreas A1 - Bettge, Dirk A1 - Kranzmann, Axel A1 - Knauer, S. T1 - Droplet corrosion of CO2 transport pipeline steels N2 - In this work, the focus was set on the corrosion process of condensate as drops on the surface of carbon steels (X52, X70), martensitic steel UNS S41500, and superaustenite UNS N08031 in CO2 atmosphere with impurities at 278 K (to simulate the transportation condition in a buried pipeline). Exposure tests were performed at both normal pressure and high pressure where CO2 is supercritical or in dense phase. The drop, 1 ‑ 10 μL in volume, was prepared by dropping CO2 saturated ultra-pure water onto the surface of steel coupons in a one-liter-autoclave. The CO2 gas stream, simulating the oxyfuel flue gas with varying concentration of impurities (SO2 and O2 ), was then pumped into the autoclave to observe the condensation and corrosion impacts of impurities. Comparable exposure tests were carried out with the same gas mixture and the same volume of water as vapor to observe the drop formation and the corrosion process that follows. The wettability and stability of drops on the surface of steel coupons in CO2 supercritical/dense phase environment was evaluated additionally by contact angle measurement. T2 - NACE International Annual Corrosion Conference CY - Phoenix, AZ, USA DA - 15.04.2018 KW - Geothermal KW - Coating KW - SiO2 KW - Polyaniline KW - Corrosion PY - 2018 SP - 10845, 1 EP - 11 PB - Omnipress CY - Houston AN - OPUS4-44917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sonntag, Nadja A1 - Jürgens, Maria A1 - Roohbakhshan, Farshad A1 - Agudo Jácome, Leonardo A1 - Olbricht, Jürgen T1 - Dwell-Fatigue and Cyclic Softening of Grade P92 Steel under LCF and TMF Conditions N2 - Tempered martensite-ferritic steels, such as the grade P92 steel studied in this contribution, exhibit pronounced macroscopic cyclic softening under isothermal low-cycle fatigue (LCF) and non-isothermal thermomechanical fatigue (TMF) conditions, which is considered to be the predominant degradation mechanism in high-temperature fatigue in this and other material groups. However, such softening processes are highly complex since microscopic (e.g., recovery) and macroscopic (e.g., crack initiation and growth), as well as global and local effects superimpose, especially under creep-fatigue conditions. In this contribution, we discuss the cyclic deformation and softening behavior of P92 in strain-controlled LCF, in-phase (IP) TMF, and out-of-phase (OP) TMF tests with and without dwell times in the temperature range from 300 °C to 620°C. EBSD-based dislocation analysis on various fatigued material states confirms the continuous redistribution and annihilation of geometrically necessary dislocations in all studied states, which can be quantitatively correlated with macroscopic softening despite different damage mechanisms for different test types. Deviations from this correlation are observed for OP TMF and LCF with dwell times, i.e., for conditions where optical microscopy reveals pronounced crack-oxidation interactions at the specimen surfaces. T2 - LCF9 - Ninth International Conference on Low Cycle Fatigue CY - Berlin, Germany DA - 21.06.2022 KW - LCF KW - TMF KW - EBSD PY - 2022 DO - https://doi.org/10.48447/LCF9-2022-111 AN - OPUS4-55128 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Ralf A1 - Reinsch, Stefan T1 - Dynamic Mechanical Analysis (DMA): Viscoelasticity N2 - Der Vortrag gibt einen Überblick über die am FB 56 der BAM betriebene Dynamisch-Mechanische Analyse mit dem Schwerpunkt auf Anwendungen für Glas N2 - The talk presents an overview over the method of Dynamic Mechanical Analysis used at the BAM division 5.6 Glass mainly focussed on glasses. T2 - Seminar Instrumentelle Analytik, Fakultät III Prozesswissenschaften, Lehrstuhl Keramik TU Berlin CY - Berlin, Germany DA - 25.01.2019 KW - Dynamisch Mechanische Analyse KW - Dynamic mechanical analysis KW - Glas PY - 2019 AN - OPUS4-50436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Sachs, Patrick T1 - Dynamic mechanical analysis of epoxy-matrix cross linking measured in-situ using an elastomer container N2 - A new patented dynamic mechanical analysis (DMA) is presented, where the tensile, bending- or torsional stiffness of a media can be characterized in-situ during the phase transition from liquid to solid. An epoxy system, e.g. Hexion L285/H287, is filled into an elastomer container, such as a silicone tube. This can be mounted into a conventional DMA and, based on a linear viscoelastic approach, the storage modulus (E’;G’), the loss modulus (E’’;G’’) and the loss angle tan(delta) can be measured at constant temperature as a function of time in order to investigate the liquid to sol-gel to solid transition. With this new method, the stiffness increase as a result of the cure process can be directly measured more precisely than with a rheometer in a shear plate set-up, because using an elastomer container gives a defined cross section for calculating the Young’s modulus. T2 - 20th European Conference on Composite Materials, ECCM20 CY - Lausanne, Switzerland DA - 26.06.2022 KW - Dynamic mechanical analysis (DMA) KW - Thermoset polymers KW - Cure process KW - Cross linking PY - 2022 AN - OPUS4-55213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trappe, Volker A1 - Sachs, Patrick ED - Vassilopoulos, A. P. ED - Michaud, V. T1 - Dynamic mechanical analysis of epoxy-matrix cross linking measured in-situ using an elastomer container N2 - A new patented dynamic mechanical analysis (DMA) is presented, where the tensile, bending- or torsional stiffness of a media can be characterized in-situ during the phase transition from liquid to solid. An epoxy system, e.g. Hexion L285/H287, is filled into an elastomer container, such as a silicone tube. This can be mounted into a conventional OMA and, based on a linear viscoelastic approach, the storage modulus (E';G'), the loss modulus (E'';G'') and the loss angle tan(δ) can be measured at constant temperature as a function of time in order to investigate the liquid to sol-gel to solid transition. With this new method, the stiffness increase as a result of the cure process can be directly measured more precisely than with a rheometer in a shear plate set-up, because using an elastomer container gives a defined cross section for calculating the Young's modulus. T2 - 20th European Conference on Composite Materials CY - Lausanne, Switzerland DA - 26.06.2022 KW - Cross linking KW - Dynamic mechanical analysis (DMA) KW - Thermoset polymers KW - Cure process PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569651 UR - https://infoscience.epfl.ch/record/298799 SN - 978-2-9701614-0-0 VL - Vol. 5 - Applications and structures SP - 181 EP - 186 PB - Composite Construction Laboratory (CCLab) CY - Lausanne AN - OPUS4-56965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria A1 - Mohring, W. A1 - Hesse, René A1 - Agudo Jácome, Leonardo A1 - Stephan-Scherb, C. T1 - Early Material Damage in Equimolar CrMnFeCoNi in Mixed Oxidizing/Sulfiding Hot Gas Atmosphere N2 - The challenges to use more varied fuels at medium and high temperatures above 500 °C need to be addressed by tuning the materials towards a better resistance against increased corrosion. As a first step the corrosion processes need to be better understood, especially in the case of the unavoidable and highly corrosive sulfur-based gases. In this work oxidation/sulfidation of an equimolar CrMnFeCoNi high entropy alloy is studied at an early stage after hot gas exposure at 600 °C for 6 h in 0.5% SO2 and 99.5% Ar. The oxidation process is studied by means of x-ray diffraction, scanning and transmission electron microscopy and supported by thermodynamic calculations. It is found that the sulfur does not enter the bulk material but interacts mainly with the fast-diffusing manganese at grain boundary triple junctions at the alloy surface. Sub-micrometer scaled Cr-S-O rich phases close to the grain boundaries complete the sulfur-based phase formation. The grains are covered in different Fe, Mn and Cr based spinels and other oxides. T2 - Priority Programme (Schwerpunktprogramm) Compositionally Complex Alloys - High Entropy Alloys (SPP CCA - HEA) CY - Bayreuth, Germany DA - 12.07.2022 KW - High entropy alloy KW - Corrosion KW - Sulfiding KW - Cantor alloy KW - Transmission electron microscopy PY - 2022 AN - OPUS4-55395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Manzoni, Anna Maria A1 - Mohring, W. A1 - Hesse, René A1 - Agudo Jácome, Leonardo A1 - Stephan-Scherb, C. T1 - Early Material Damage in Equimolar CrMnFeCoNi in Mixed Oxidizing/Sulfiding Hot Gas Atmosphere N2 - The use of more and more varied fuels implies an increased list of criteria that need to be addressed when choosing a material for a combustion chamber and its supply pipes. The materials must be very resistant against corrosion, especially when the process takes place at temperatures above 500°C. In this work the influence of SO2 on the surface of the “Cantor alloy” is investigated. T2 - HEA-Symposium "Potential for industrial applications" CY - Dresden, Germany DA - 12.05.2022 KW - High entropy alloy KW - Corrosion KW - Sulfiding KW - Transmission electron microscopy PY - 2022 AN - OPUS4-55397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Menneken, Martina A1 - Falk, Florian A1 - Stephan-Scherb, Christiane T1 - Early stages of corrosion in hot, aggressive environments N2 - We investigated the effect of water vapor in the initial stages of SO2 corrosion of an Fe-9Cr-0.5Mn model alloy at 650 °C. Two separate experiments were run, one with 99.5%-Ar + 0.5%-SO2 and one with 69.5%-Ar + 0.5%-SO2 with 30%-H2O atmosphere. During the experiment the scale growth was observed in-situ, using energy dispersive X-ray diffraction (EDXRD). Our results confirm an increased speed of oxygen transport into the material, with the addition of water, while the transport of sulfur appears to be less affected. T2 - Sektionstreffen der DMG Sektionen "Angewandte Mineralogie in Umwelt & Technik" und "Chemie, Physik und Kristallographie der Minerale" CY - Bad Windsheim, Germany DA - 28.02.2018 KW - Corrosion KW - In-situ KW - EDXRD PY - 2018 AN - OPUS4-45369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stephan-Scherb, Christiane A1 - Menneken, Martina A1 - Nützmann, Kathrin A1 - Falk, Florian A1 - de Oliveira Guilherme Buzanich, Ana A1 - Witte, Steffen A1 - Radtke, Martin T1 - Early stages of high temperature oxidation/sulfidation studied by synchrotron x-ray diffraction and spectroscopy N2 - Ferritic high temperature alloys are widely used as boiler tube and heat exchanger materials in coal, biomass and co-fired power plants. All technologies have in common that the applied materials are exposed to different temperatures, process pressures and reactive atmospheres that lead to a change of the material properties and a further degradation of the material. Material changes caused by aging in highly corrosive and toxic gases such as SO2 are mainly studied ex situ after the reaction is finished. The solid material is deposited in the atmosphere for a certain period of time, and material changes are then examined by various microscopic techniques such as optical microscopy (OM), electron microprobe analysis (EMPA), scanning electron microscopy (SEM and TEM) and X-ray diffraction (XRD). Nevertheless, extensive efforts were made to study material changes of high temperature alloys under oxidizing and reducing atmospheres by environmental scanning electron microscopy or in situ TEM techniques However, the possibilities of microscopic in situ techniques are very limited for the use of highly corrosive and toxic gases such as SO2. Since Sulfur induced corrosion at temperatures relevant for coal and biomass fired power plants, which is causing breakaway oxidation and sulfide precipitation at grain boundaries, is still of scientific interest, the current work focuses on the effect of SO2 in an initial stage of corrosion of ferritic alloys. For the analysis of early stages of combined oxidation and sulphidation processes of Fe-Cr model alloys the usage of a light furnace to conduct a rapid reactive annealing experiment is feasible. Previous studies presented distinct results of the influence of chromium on early high temperature corrosion by SO2 by this technique and subsequent classical metallographic analyses. However, it is still not possible to trace the corrosion mechanism in real time by conducting single aging experiments. The current work introduces two different approaches to study the initial stages of high temperature oxidation processes by applying above state of the art X-ray diffraction and spectroscopy methods. One part focuses on the real time observation of the formation of corrosion products such as oxides and sulfides by energy dispersive X-ray diffraction (EDXRD). The potential of this technique to study crystallization and growth processes of thin films in a reactive environment in real time was previously shown for different compound semiconductors. This approach was now applied to follow oxidation and sulphidation processes of ferritic model alloys in SO2 and SO2/H2O environments. The diffraction signals of the X-rays were detected during the corrosion process and the peak area and positions were analyzed as a function of time. This procedure enables monitoring external oxide growth and material loss in real time in an early stage of corrosion. The other part of the current work presents the possibilities of X-ray absorption near edge structure spectroscopy (XANES) to characterize oxide scales and their growth mechanisms. Precise phase identification and quantification of corrosion products in a multi-phase oxide/sulfide scale is a pre-requisite to understand diffusion paths of metal ions and gas components. It is a challenging task to distinguish structurally similar reaction products such as Fe3O4 and FeCr2O4 especially in thin films with texture effects by diffraction. To illustrate for example Cr-out diffusion of an alloy throughout an inner and external oxide scale the differentiation of Fe3O4 and FeCr2O4 is indispensable. XANES uses the photoionization effect at the metal absorption edge in an aging product and accesses by this structural and chemical information. The current work uses XANES at the Fe-K and Cr-K absorption edge to identify various aging products grown as thin layers on alloys after short time aging experiments. A reaction chamber for combining high temperature oxidation experiments with surface sensitive X-ray absorption near edge structure spectroscopy will be introduced and first results of XANES on scales at high temperatures will be presented. T2 - ISHOC 2018 CY - Matsue, Japan DA - 22.10.2018 KW - Corrosion KW - Sulfidation KW - In situ KW - Diffraction KW - XANES PY - 2018 AN - OPUS4-47278 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 - TY - GEN A1 - López de Ipina, J.-M. A1 - Arevalillo, A. A1 - Martín, A. A1 - Caillard, B. A1 - Marcoulaki, E. A1 - Aguerre- Charol, O. A1 - van Duuren-Stuurman, B. A1 - Hodoroaba, Vasile-Dan A1 - Viitanen, A.-K. A1 - Witters, H. A1 - Vercauteren, S. A1 - Persson, K. A1 - Bard, D. A1 - Evans, G. A1 - Jensen, K.A. A1 - Himly, M. A1 - Scalbi, S. A1 - Papin, A. A1 - Le Bihan, O. A1 - Kanerva, T. A1 - Tirez, K. A1 - Frijns, E. A1 - Niga, P. A1 - Eleftheriadis, K. A1 - Travlos, A. A1 - Geppert, M. A1 - Himly, M. A1 - Radnik, Jörg A1 - Kuchenbecker, Petra A1 - Resch-Genger, Ute A1 - Fraboulet, I. A1 - Bressot, C. A1 - Rissler, J. A1 - Gaucher, R. A1 - Binotto, G. A1 - Krietsch, Arne A1 - Braun, A. A1 - Abenet, S. A1 - Catalan, J. A1 - Verstraelen, S. A1 - Manier, N. A1 - Manzo, S. A1 - Fransman, S. A1 - Queron, J. A1 - Charpentier, D. A1 - Taxell, D. A1 - Säämänen, A. A1 - Brignon, J.-M. A1 - Jovanovic, A. A1 - Bisson, M A1 - Neofytou, P. T1 - EC4Safenano - Catalogue of Services N2 - The publicly available document encapsulates the first version of the Catalogue of Services of the future EC4Safenano Centre (CoS 2019). The CoS 2019 is structured in 12 Service Categories and 27 Service Topics, for each of the 12 categories considered. This architecture configures a 12 x 27 matrix that allows ordering the potential EC4Safenano offer in 324 types of services/groups of services. Each type of service/group of services is described, in a simple and friendly way, by means of a specific service sheet: the EC4Safenano - Service Data Sheet (EC4-SDS). These EC4-SDSs allow structuring and summarizing the information of each service, providing the customer with a concise view of characteristics of the service and also the contact details with the service provider. The CoS 2019 deploys a map of services consisting of a set of 100 EC4-SDSs, covering 7 of the 12 Service Categories and 17 of the 27 Service Topics. The harmonization of services is visualized as a future necessary step in EC4Safenano, in order to strengthen the offer and provide added value to customers with a growing offer of harmonized services in future versions of the CoS. The information contained in this document is structured in 3 main sections, as follows: • Catalogue structure. This section describes in short the main characteristics of the CoS 2019. • Catalogue content. This section represents the core part of the document and encapsulates the set of 100 SDSs displaying the offer proposed by the CoS 2019. • Online Catalogue. This section describes the resources implemented by EC4Safenano to facilitate the on-line consultation of the CoS 2019 by customers and other interested parties. KW - Nano-safety KW - Analytical services KW - Nanomaterials KW - Catalogue of services KW - EC4SafeNano KW - European Centre PY - 2021 UR - https://ec4safenano.eu-vri.eu/Public/Guidance SP - 1 EP - 72 PB - EU-VRi – European Virtual Institute for Integrated Risk Management CY - Stuttgart, Germany AN - OPUS4-52943 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Franchin, G. A1 - Zocca, Andrea A1 - Karl, D. A1 - Yun, H. A1 - Tian, X. T1 - Editorial: Advances in additive manufacturing of ceramics N2 - Recently, additive manufacturing of ceramics has achieved the maturity to be transferred from scientific laboratories to industrial applications. At the same time, research is progressing to expand the boundaries of this field into the territory of novel materials and applications. This feature issue addresses current progress in all aspects of additive manufacturing of ceramics, from parts design to feedstock selection, from technological development to characterization of printed components. KW - Additive manufacturing KW - Ceramic PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549361 DO - https://doi.org/10.1016/j.oceram.2022.100277 SN - 2666-5395 VL - 10 SP - 1 EP - 2 PB - Elsevier CY - Amsterdam AN - OPUS4-54936 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 - CONF A1 - Stephan-Scherb, Christiane A1 - Schulz, Wencke A1 - Karafiludis, Stephanos A1 - Schneider, Mike A1 - Laplanche, Guillaume T1 - Effect of a mixed atmosphere H2O-O2-SO2 on the oxidation kinetics and phase formation on CrMnFeCoNi and CrCoNi N2 - The high-entropy alloy (HEA) CrMnFeCoNi and the medium-entropy alloy (MEA) CrCoNi with a face-centered cubic (fcc) structure have excellent mechanical properties and are considered for high-temperature applications. Both materials were exposed under several oxidized atmospheres in a wide temperature range/regime. Mn-oxide (Mn3O4, Mn2O3) was mainly formed on the HEA and Cr2O3 on the MEA. The fast diffusion of manganese prevents the formation of a continuous chromia layer on CrMnFeCoNi in Ar-O2, Ar-H2O and Ar-SO2 at 800°C. The Cantor alloy and his ternary subsystem CrCoNi were exposed in Ar-O2-H2O-SO2 at 800°C up to 96 h to clarify their oxidation behavior in a mixed atmosphere. The oxidized samples were analyzed by weight measurement, scanning electron microscopy (SEM), and X-ray diffraction analysis (XRD). It was found that mass gain of all samples increased with increasing exposure time. The oxidation rate of the Cantor alloy is significantly higher than that of the ternary alloy system. T2 - International Conference on High Entropy Materials CY - Berlin, Germany DA - 27.09.2020 KW - High Entropy Alloys KW - Medium Entropy Alloys KW - High temperature corrosion KW - Oxidation KW - Sulfidation PY - 2020 AN - OPUS4-51488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cysne Barbosa, Ana Paula A1 - Azevedo do Nascimento, Allana A1 - Pavasarytė, Lina A1 - Trappe, Volker A1 - Melo, D. T1 - Effect of addition of thermoplastic self-healing agent on fracture toughness of epoxy N2 - Self-healing agents have the potential to restore mechanical properties and extend service life of composite materials. Thermoplastic healing agents have been extensively investigated for this purpose in epoxy matrix composites due to their strong adhesion to epoxy and their ability to fill in microcracks. One of the most investigated thermoplastic additives for this purpose is poly(ethylene-co-methacrylic acid) (EMAA). Despite the ability of thermoplastic healing agents to restore mechanical properties, it is important to assess how the addition of thermoplastic healing agents affect properties of the original epoxy material. In this work, EMAA was added to epoxy resin and the effect of the additive on fracture toughness of epoxy was evaluated. Results indicate that although added in low concentrations, EMAA can affect fracture toughness. T2 - 6th Brazilian Conference on Composite Materials CY - Tiradentes, Minas Gerais, Brazil DA - 14.08.2022 KW - Epoxy KW - Self-healing KW - Thermoplastic KW - Fracture PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572707 SN - 978-65-00-49386-3 DO - https://doi.org/10.29327/566492 SN - 2316-1337 SP - 219 EP - 222 AN - OPUS4-57270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aristia, Gabriela A1 - Le, Quynh Hoa A1 - Bäßler, Ralph T1 - Effect of CO2 gas on carbon steel corrosion in an acidic-saline based geothermal fluid N2 - Geothermal energy is one of the most promising energy resources to replace fossil fuel. To extract this energy, hot fluids of various salts and gases are pumped up from a geothermal well having a certain depth and location. Geothermal wells in volcanic regions often contain highly corrosive CO2 and H2S gases that can be corrosive to the geothermal power-plants, which are commonly constructed of different steels, such as carbon steel. This research focuses on the corrosion behaviour of carbon steel exposed to an artificial geothermal fluid containing CO2 gas, using an artificial acidic-saline geothermal brine as found in Sibayak, Indonesia. This medium has a pH of 4 and a chloride content of 1,500 mg/L. Exposure tests were conducted for seven days at 70 °C and 150 °C to simulate the operating temperatures for low and medium enthalpy geothermal sources. Surface morphology and cross-section of the specimens from the above experiments were analysed using scanning electron microscope (SEM) and energy dispersive X-ray (EDX). Electrochemical tests via open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) were performed to understand the corrosion processes of carbon steel in CO2-containing solution both at 70 °C and 150 °C. Localized corrosion was observed to a greater extent at 70 °C due to the less protectiveness of corrosion product layer compared to that at 150 °C, where FeCO3 has a high corrosion resistance. However, a longer exposure test for 28 days revealed the occurrence of localized corrosion with deeper pits compared to the seven-day exposed carbon steel. In addition, corrosion product transformation was observed after 28 days, indicating that more Ca2+ cations incorporate into the FeCO3 structure. T2 - EUROCORR 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Carbon steel KW - CO2 KW - EIS KW - Geothermal KW - Corrosion PY - 2019 SP - Paper 200245, 1 EP - 5 CY - Madrid, Spain AN - OPUS4-49099 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfennig, A. A1 - Kranzmann, Axel T1 - Effect of CO2, atmosphere and pressure on the stability of C35CrMo17 stainless steel in laboratory CCS-environment N2 - During carbon sequestration the CO2-induced corrosion of injection pipe steels is a relevant safety issue when emission gasses are compressed into deep geological layers. The reliability of the high alloyed steel X35CrMo17 suitable as injection pipe for the geological onshore CCS-site (Carbon Capture and Storage) in the Northern German Basin, is demonstrated in laboratory experiments in equivalent corrosive environment (T = 60 °CC, p = 1–100 bar, aquifer water, CO2-flow rate of 9 L/h, 700–8000 h exposure time). Corrosion kinetics and microstructure were characterized and compared to other potential injection pipe steels (42CrMo4, X46Cr13, X20Cr13 and X5CrNiCuNb16-4). T2 - 14th Greenhouse Gas Control Technologies Conference CY - Melbourne, Australia DA - 21.10.2018 KW - Steel KW - Supercritical CO2 KW - Pipeline KW - Corrosion KW - CO2-storage PY - 2019 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-50382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Wencke A1 - Laplanche, G. A1 - Schneider, M. A1 - Stephan-Scherb, Christiane T1 - Effect of corrosive atmosphere on the oxidation behavior of CrMnFeCoNi and CrCoNi alloys N2 - High- and medium-entropy alloys (HEAs and MEAs) constitute a new class of materials. Those with a face-centered cubic (fcc) structure from the Cr-Mn-Fe-Co-Ni system have excellent mechanical properties and are considered for high-temperature applications since diffusion in these alloys was reported to be sluggish. However, their corrosion resistance at high temperatures must still be evaluated to further qualify them for such kinds of applications. Various groups studied the oxidation behavior of HEAs and MEAs under (dry) laboratory and artificial air as well as CO2/CO mixtures in different temperature ranges. Adomako et al. carried out oxidation tests in dry air between 800 °C and 1000 °C for 24 h in equiatomic CrCoNi, CrMnCoNi, and CrMnFeCoNi alloys. The authors showed that CrCoNi exhibits the best corrosion resistance at 800 °C due to the formation of a protective Cr2O3 layer. The matrix below the oxide scale was reported to be correspondingly depleted in Cr. It was further shown that the addition of Mn and Fe to CrCoNi changes the phase composition of the oxide scale at 800 °C. A Mn2O3 layer was grown during oxidation on CrMnCoNi and CrMnFeCoNi and a Cr2O3 scale was formed at the matrix/oxide scale interface. Beneath these oxide layers, Mn- and Cr-depleted zones were detected. These phase morphologies demonstrate the inward diffusion of oxygen and outward diffusion of Cr and Mn resulting in the formation of Cr2O3 and Mn2O3. In the present study, the corrosion resistance of CrMnFeCoNi and CrCoNi were confirmed and additionally characterized under further oxidizing atmospheres at 800 °C including Ar-2 Vol.% O2, Ar-2 Vol.% H20, and Ar-2 Vol.% SO2 mixtures. T2 - 10th International Symposium on High-Temperature Corrosion and Protection of Materials CY - Online meeting DA - 28.03.2021 KW - High-entropy alloys KW - High-temperature corrosion KW - Chromium oxide KW - Manganese oxide PY - 2021 AN - OPUS4-53143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -