TY - JOUR A1 - Scheffler, Franziska A1 - Fleck, Mirjam A1 - Busch, Richard A1 - Casado, Santiago A1 - Gnecco, Enrico A1 - Tielemann, Christopher A1 - Brauer, Delia S. A1 - Müller, Ralf T1 - Surface Crystallization of Barium Fresnoite Glass: Annealing Atmosphere, Crystal Morphology and Orientation JF - Crystals N2 - Controlled oriented crystallization of glass surfaces is desired for high precision applications, since the uppermost crystal layer significantly influences the properties of the material. In contrast to previous studies, the data presented here deal with separated crystals growing at defect-free surfaces in four atmospheres with different degrees of humidity (ambient/dry air, argon and vacuum). A glass with the composition 2 BaO–TiO2–2.75 SiO2 was heat-treated at 825 °C until fresnoite (Ba2TiSi2O8) grew to a significant size. The crystal growth rate is found to increase with increasing humidity. The morphology of the crystals changes from highly distorted dendrites in the driest atmosphere (vacuum) to circular/spear-head-shaped crystals in the wettest atmosphere (ambient air), which we attribute to a decrease in viscosity of the glass surface due to water uptake. The least distorted crystals appear in the form of depressions of up to 6 µm. This has an influence on the observed crystal orientation, as measured by electron backscatter diffraction (EBSD). The pulled-in crystals change the orientation during growth relative to the flat glass surface due to an enrichment in SiO2 at the crystal fronts. This confirms that the orientation of crystals is not fixed following nucleation. KW - Fresnoite KW - Surface crystallization KW - Crystal growth KW - Crystal morphology KW - Crystal orientation KW - EBSD PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587230 DO - https://doi.org/10.3390/cryst13030475 VL - 13 IS - 3 SP - 1 EP - 17 PB - MDPI AG CY - Basel AN - OPUS4-58723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Quantitative Microstructural Analysis - VAMAS TWA 37 & Liaison with ISO/TC 202 Microbeam Analysis N2 - The progress in activities on Microbeam Analysis under VAMAS/TWA 37 is reviewed. Particularly the liaison with the new projects within the ISO technical committee TC 202 is presented and discussed with respect to the identification and launching corresponding VAMAS projects. The ongoing project "FIB sample processing for TEM" is presented in detail. T2 - Versailles Project on Advanced Materials and Standards (VAMAS) 48th Steering Committee Meeting CY - New Delhi, India DA - 9.10.2023 KW - TEM KW - FIB KW - EBSD KW - Sample preparation KW - VAMAS KW - Standardisation KW - Interlaboratory comparisons PY - 2023 UR - https://www.nplindia.org/index.php/amcsnzt_2023/ AN - OPUS4-58538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cios, G. A1 - Winkelmann, A. A1 - Nolze, Gert A1 - Tokarski, T. A1 - Rychlowski, L. A1 - Dan, L. A1 - Bala, P. T1 - Mapping of lattice distortion in martensitic steel—Comparison of different evaluation methods of EBSD patterns JF - Ultramicroscopy N2 - To visualize the varying tetragonal distortions in high carbon martensitic steels by EBSD, two different approaches have been applied on backscattered Kikuchi diffraction (BKD) patterns. A band-edge refinement technique called Refined Accuracy (RA) (Oxford Instruments) is compared with a technique called Pattern Matching (PM), which optimizes the fit to a simulated BKD signal. RA distinguishes between hypothetical phases of different fixed 𝑐∕𝑎, while PM determines a best fitting continuous 𝑐∕𝑎 by projective transformation of a master pattern. Both techniques require stored BKD patterns. The sensitivity of the 𝑐∕𝑎-determination was tested by investigating the microstructure of a ferritic steel with an expected 𝑐∕𝑎 = 1. The influence of the Kikuchi pattern noise on 𝑐∕𝑎 was compared for a single or 40 averaged frames per measuring point, and turned out to be not significant. The application of RA and PM on the martensitic microstructure delivered qualitatively similar maps of 𝑐∕𝑎. The comparison of RA and PM shows that RA is suitably fast and precise during mapping the martensite 𝑐∕𝑎 ratio in analyses of high carbon martensite, especially for fast initial surveys. As RA leads quantitatively to higher noise in 𝑐∕𝑎, the PM analysis can be used for higher precision results. KW - EBSD KW - Steel KW - Martensite KW - Tetragonality KW - Strain PY - 2023 DO - https://doi.org/10.1016/j.ultramic.2023.113824 VL - 253 SP - 1 EP - 11 AN - OPUS4-58158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - (Pre)Standardisation and Metrology in Microbeam Analysis – Ongoing Activities and Opportunities N2 - The presentation addresses the current ongoing projects as well as the gaps and opportunities in microbeam analysis within ISO/TC 202 Microbeam Analysis standardisation body and in-liaison Technical Working Areas (TWAs) at the pre-standardization platform of VAMAS (Versailles Project on Advanced Materials and Standards). T2 - EMAS 2023 - 17th European Workshop on Modern Developmennts and Applications in Microbeam Analysis - General Assembly CY - Krakow, Poland DA - 07.05.2023 KW - Microbeam analysis KW - EDS KW - Electron microscopy KW - Inter-laboratory comparison KW - EBSD KW - Standardisation PY - 2023 AN - OPUS4-57483 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -