TY - JOUR A1 - Nolze, Gert A1 - Payton, E. A1 - Winkelmann, Aimo T1 - Advanced EBSD Pattern Interpretation through Iterative Post-Processing N2 - Since the BSE signal depends on many factors, like the chemistry of the phase and the acceleration voltage, the size and position of the detector array is (slightly) different from phase to phase so that an (iterative) post-processing of the stored patterns is highly recommended. The derived BSE signal can be used for phase assignment in high resolution and high speed maps when EBSD fails and/or EDS (energy dispersive spectroscopy) needs too much time for a suitable and parallel signal acquisition. KW - Electron backscatter diffraction KW - Phase identification KW - Microstructure KW - SEM PY - 2013 DO - https://doi.org/10.1017/S1431927613005631 VL - 19 IS - Suppl. 2 SP - 728 EP - 729 AN - OPUS4-37986 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Campos de Oliveira, Paula T1 - Advancing microstructural characterisation of ceramic cores for aerospace: from state-of-the-art to in-situ synchrotron X-ray computed tomography N2 - Ceramic cores are crucial for manufacturing turbine blades in aircraft engines, creating intricate cooling channels that improve engine efficiency and reduce emissions. During high-temperature casting, the cores undergo significant microstructural changes, including phase transitions, particle rearrangements, and porosity transformations, which can affect their properties and must be carefully controlled. State-of-the-art characterisation techniques for ceramic cores mostly rely on 2D methods, such as scanning and transmission electron microscopy. While valuable, these methods are limited in capturing the 3D complexity of the material. Advances in X-ray computed tomography (XCT) offer a more comprehensive perspective on 3D microstructures, but conventional XCT often lacks the resolution and in-situ capabilities to study microstructural evolution under casting conditions. Synchrotron XCT (SXCT) addresses these limitations, offering high spatial and temporal resolution with features down to 1 µm, enabling in-situ investigations. This study highlights the potential of SXCT, revealing previously unseen 3D microstructural features in ceramic cores, such as agglomeration, porosity evolution, surface reactions, microcracking, and particle orientation. These findings provide a more realistic view of dynamic changes during casting, advancing the understanding of core behaviour. Despite its advantages, SXCT is still rarely used in the field due to challenges such as limited access to synchrotron facilities and sample movement artifacts. Future developments, including high-temperature and vacuum compatible CT setups, could enhance this technique, leading to a better optimisation of ceramics performance. T2 - XIXth Conference of the European Ceramic Society (ECERS 2025) CY - Dresden, Germany DA - 31.08.2025 KW - Synchrotron KW - X-ray Computed Tomography KW - Ceramic core KW - Aerospace KW - Microstructure PY - 2025 AN - OPUS4-64050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis T1 - Assessing the low cycle fatigue behaviour of additively manufactured Ti-6Al-4V: Challenges and first results N2 - The understanding of process-microstructure-property-performance (PMPP) relationships in additive manufacturing (AM) of metals is highly necessary to achieve wide-spread industrial application and replace conventionally manufactured parts, especially regarding safety-relevant applications. To achieve this understanding, reliable data and knowledge regarding material’s microstructure-property relationships (e.g. the role of defects) is needed, since it represents the base for future more targeted process optimizations and more reliable calculations of performance. However, producing reliable material data and assessing the AM material behaviour is not an easy task: big challenges are e.g. the actual lack of standard testing methods for AM materials and the occasional difficulties in finding one-to-one comparable material data for the conventional counterpart. This work aims to contribute to end this lack of reliable material data and knowledge for the low cycle fatigue behaviour of the most used titanium alloy in aerospace applications (Ti-6Al-4V). For this purpose, two sets of test specimens were investigated. The first set was manufactured from cylindrical rods produced by an optimized DED-L process and the second was manufactured from a hot formed round bar. The test specimens were cyclically loaded until failure in the low-cycle-fatigue (LCF) regime. The tests were carried out according to ISO 12106 between 0.3 to 1.0 % axial strain amplitude from room temperature up to 400°C. The LCF behaviour is described and compared between materials and with literature values based on cyclic deformation curves and strain-based fatigue life curves. Besides, the parameters of Manson-Coffin-Basquin relationship were calculated. The microstructures (initial and after failure) and fracture surfaces were comparative characterized. Thereby, the focus lied on understanding the role of grain morphology and defects on the failure mechanisms and fatigue lifetimes. For this latter characterization, optical microscopy (OM), scanning electron microscopy (SEM) and micro computed tomography (µCT) were used. T2 - 4th International Symposium on Fatigue Design and Material Defects CY - Online meeting DA - 26.05.2020 KW - Ti-6Al-4V KW - Additive manufacturing KW - Low cycle fatigue KW - Micro computed tomography KW - Microstructure PY - 2020 AN - OPUS4-50893 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Assessing the safety of new technologies: Summary of Project AGIL N2 - In Additive Manufacturing everybody is talking about Free Form, Unconventional Design, Re-thinking Components, “Think out of the box”. However, there are a few outstanding question: a) What are the material properties ? They certainly differ from literature values for conventional materials; b) How about the microstructure? It is different from conventional materials. Does it stay so with ageing? How does it form? c) Do we properly take residual stress into account? We often blame them for our ignorance about failure scenarios. d) Do we apply tailored heat treatments? Very often, we follow conventional schedules… This talk describes the summary of the efforts carried out within the BAM Project AGIL. At BAM, we aimed to thoroughly investigate the microstructure and how it evolves as a function of load and temperature (service), to determine the material properties after different process and service conditions, to properly determine residual stress and the way it impacts mechanical properties and component performance, to properly quantify the impact of (unavoidable?) defects, and to determine heat treatments tailored to the process-specific material (stress relieve, microstructure homogenization etc.). The Project AGIL was and is intimately coupled with the project ProMoAM, dealing with online monitoring of AM processes. T2 - Workshop In-situ Monitoring and Microstructure Development in Additive Manufactured Alloys CY - Online meeting DA - 19.04.2021 KW - Mechanical properties KW - Additive manufacturing KW - Residual Stress KW - Microstructure KW - Fatigue KW - Creep PY - 2021 AN - OPUS4-52581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, Lei A1 - Kannengießer, Thomas T1 - Austenite grain growth and microstructure control in simulated heat affected zones of microalloyed HSLA steel N2 - The roles of microalloying niobium, titanium and vanadium for controlling austenite grain growth, microstructure evolution and hardness were investigated at different simulated heat affected zones (HAZ) for high strength low alloy (HSLA) S690QL steel. High resolution FEG-SEM has been used to characterize fine bainitic ferrite, martensite and nanosized second phases at simulated coarse and fine grain HAZs. It was found that for Ti bearing steel (Ti/N ratio is 2) austenite grain had the slowest growth rate due to the presence of most stable TiN. The fine cuboidal particles promoted intragranular acicular ferrite (IGF) formation. Nb bearing steel exhibited relatively weaker grain growth retardation compared with titanium bearing steels and a mixed microstructure of bainite and martensite was present for all simulated HAZs. IGF existed at coarse grain HAZ of Ti+V bearing steel but it was totally replaced by bainite at fine grain HAZs. Hardness result was closely related to the morphology of bainitic ferrite, intragranular ferrite and second phases within ferrite. The microstructure and hardness results of different simulated HAZs were in good agreement with welded experimental results. KW - Hardness measurement KW - Microstructure KW - Microalloyed steel KW - Welding KW - Grain growth PY - 2014 DO - https://doi.org/10.1016/j.msea.2014.06.106 SN - 0921-5093 VL - 613 SP - 326 EP - 335 PB - Elsevier B.V. AN - OPUS4-36520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bruno, Giovanni T1 - Avoid living dangerously: non-destructive characterization of AM parts from powder to end-of-life N2 - The freeform and the revolutionary design possibilities offered by additive manufacturing have skyrocketed the amount of optimization studies in the realm of engineering, and metallic additive manufactured parts are becoming a reality in industry. Not surprisingly, this has not been paralleled by a similar enthusiastic wave in the realm of materials science, and still very little is known about AM materials properties. This has the consequence that, typically, conventional materials properties are still used in design and even in simulations. lt is necessary to dig a lot deeper than at present, in order to understand these new materials classes, and in particular their microstructure and their intemal stresses, largely different from their cast or wrought companions. T2 - ISAM Konferenz 2019 CY - Dresden, Germany DA - 29.01.2019 KW - Computed Tomography KW - Microstructure KW - Metals KW - Additive Manufacturing PY - 2019 AN - OPUS4-47331 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bäßler, Ralph T1 - Book review: Materials and processes for CO2 capture, conversion and sequestration N2 - This book provides an overview on research‐topics who need to be investigated when dealing with this topic, basing on the symposium in 2014. It addresses the key challenges involved in CCS materials design, processing and modelling. Readers can get an overview on topics one should consider when working in these field and selecting current Journal articles. KW - CCS KW - CO2-Corrosion KW - Microstructure PY - 2019 DO - https://doi.org/10.1002 maco.201970044 SN - 0947-5117 SN - 1521-4176 VL - 70 IS - 04 SP - 751 EP - 752 PB - WILEY-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-47909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meng, Birgit A1 - Simon, Sebastian T1 - Characterization of Alkali-Silica Reaction Products by means of Raman Spectroscopy before and after Application of Accelerated Tests N2 - Alkali silica reaction (ASR) is a major concrete durability problem resulting in significant maintenance and reconstruction costs for concrete infrastructures all over the world. To determine whether an aggregate is potentially reactive, accelerated concrete tests are used. Aim of this study is the chemical and microstructural characterization of ASR-products formed under the performance conditions of motorway pavements and during subsequent tests on the remaining ASR susceptibility. Samples were taken from concrete motorway pavements. Some of the samples already showed first indications for beginning damages whereas others showed deteriorations only after applying a performance testing procedure for the estimation of future risk of ASR damage. In a first step ASR-products were identified by polarized light microscopy in thin sections. The reaction products where then analyzed by Raman Spectroscopy and finally the chemical composition of the ASR-products was identified by SEM with EDX. The results indicate that most reaction products show an increasing Ca/Si-ratio with progressive crack length. If an ASR-product develops inside an aggregate and moves through the cement paste, it has a high (Na+K)/Si-ratio at the beginning which decreases with increasing distance from its place of origin. The Raman spectra of the ASR-products are characterized by two broad bands indicating specific Q-species of different amorphous gel networks. Within the scope of the analysis distinctions in the microstructure and the chemical composition of the ASR-gels were detected relating to various conditions of accelerated testing. T2 - 15th International Congress on Chemistry of Cement CY - Prague, Czech Republic DA - 16.09.2019 KW - Alkali-silica reaction KW - Raman microscopy KW - Microstructure KW - Concrete motorway pavements KW - Performance test PY - 2019 AN - OPUS4-49527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia A1 - Fontana, P. A1 - Hoppe, Johannes A1 - Bilgin, S. A1 - Meng, Birgit ED - Serrat, C. ED - Casas, J. R. ED - Gibert, V. T1 - Composite Facade Elements with Self-Cleaning Surface made of Ultra-High-Performance Concrete (UHPC) N2 - In the framework of the European project H-House various concrete façade elements were developed with the aim to ensure a long service life by combining a very durable material with self-cleaning properties. The façade elements presented are made of a shell of UHPC filled with blocks of aerated autoclaved concrete as insulating material. Self-cleaning properties were realized amongst others by imprinting a microstructure into the surface during casting. The paper focuses on selected technological aspects of the manufacturing process of prototypes which had to be performed in two concreting sections. Furthermore the challenges faced when upscaling the self-cleaning properties are addressed and the strategy to assess the self-cleaning properties by measuring the contact and the roll-off angel is presented. The results show that a successfull upscalaing process requires detailed planning and that the best results can often be achieved with a moderate work effort or material use. T2 - XV International Conference on Durability of Building Materials and Components (DBMC 2020) CY - Online meeting DA - 20.10.2020 KW - Ultra-High-Performance Concrete KW - Facade Elements KW - Self-Cleaning Properties KW - Adhesive Pull-Strength KW - Microstructure KW - Architectural Concrete PY - 2020 SN - 978-84-121101-8-0 SP - 1289 EP - 1297 PB - International Center for Numerical Methods in Engineering (CIMNE) CY - Spain AN - OPUS4-51967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Werder, Julia T1 - Composite Facade Elements with Self-Cleaning Surface made of Ultra-High-Performance Concrete (UHPC) N2 - In the framework of the European project H-House various concrete façade elements were developed with the aim to ensure a long service life by combining a very durable material with self-cleaning properties. The façade elements presented are made of a shell of UHPC filled with blocks of aerated autoclaved concrete as insulating material. Self-cleaning properties were realized amongst others by imprinting a microstructure into the surface during casting. The paper focuses on selected technological aspects of the manufacturing process of prototypes which had to be performed in two concreting sections. Furthermore the challenges faced when upscaling the self-cleaning properties are addressed and the strategy to assess the self-cleaning properties by measuring the contact and the roll-off angel is presented. The results show that a successfull upscalaing process requires detailed planning and that the best results can often be achieved with a moderate work effort or material use. T2 - XV International Conference on Durability of Building Materials and Components (DBMC 2020) CY - Online meeting DA - 20.10.2020 KW - Ultra-High-Performance Concrete KW - Facade Elements KW - Self-Cleaning Properties KW - Adhesive Pull-Strength KW - Microstructure KW - Architectural Concrete PY - 2020 AN - OPUS4-51968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -