TY - JOUR A1 - Nolze, Gert A1 - Payton, E. T1 - Messengers from Space: A Scanning Electron Microscopy Investigation N2 - The macro- and microstructure of iron meteorites provide valuable insights into both the inner structure of our planet and the history of our solar system. High speed collision events in the asteroid belt send the meteorites careening toward Earth. The collisions produce unique deformation microstructures. With cooling rates on the scale of a few degrees per million years, iron meteorites can consist of crystal sizes on the order of meters prior to the collision events. These extremely slow cooling rates result in phase transformations occurring at conditions near thermodynamic equilibrium. Preserving meteorite fragments is important for future studies of phase transformations, material behavior at high strain rates, and the origin of the universe. KW - Meteorite KW - Phase identification KW - Hibbingite KW - Orientation relationship KW - Electron backscatter diffraction KW - Energy dispersive x-ray spectroscopy KW - EDX PY - 2013 IS - 3 SP - 2 EP - 4 PB - GIT Verlag AN - OPUS4-37981 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 U6 - 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 - Payton, E. A1 - Nolze, Gert T1 - The BSE signal as an additional tool for phase assignment in EBSD N2 - The presentation demonstrates how the background signal of EBSD patterns can be used for a rough assignment of phases which cannot distinguished by the diffraction signal. T2 - EBSD 2012 CY - Pittsburgh, Pennsylvania, USA DA - 19.06.2012 KW - Electron backscatter diffraction KW - Backscattered electrons KW - Kikuchi pattern KW - Phase distribution KW - Phase separation KW - Phase recognition PY - 2012 AN - OPUS4-37901 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Payton, E. J. A1 - Agudo Jácome, Leonardo A1 - Nolze, Gert T1 - Phase Identification by Image Processing of EBSD Patterns N2 - Automated electron backscatter diffraction (EBSD) is generally unable to distinguish between multiple cubic phases in a specimen without additional information, such as that obtained by simultaneous energy dispersive X-ray spectroscopy (EDS). Small particles of phases with relatively similar compositions push the limits of phase identification using simultaneous EBSD and EDS, and a mismatch exists between the spatial resolutions of these two techniques due to them having different electron interaction volumes. In a recent paper, the present authors explored using backscatter detectors mounted on top of the EBSD detector to obtain atomic number (Z) contrast images that could be used for phase segmentation in cases where the results from the EBSD and EDS signals remain ambiguous. In the present work, we show that similar information can be obtained from the raw EBSD patterns themselves at higher spatial resolution than was obtained from the backscatter detectors, with the additional advantage of having no spatial mismatch between the data collection grids. KW - Phase identification KW - Backscattered electrons KW - EBSD KW - SEM PY - 2013 U6 - https://doi.org/10.1017/S143192761300620X VL - 19 IS - Suppl. 2 SP - 842 EP - 843 AN - OPUS4-37985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Payton, E. A1 - Nolze, Gert T1 - The Backscatter Electron Signal as an Additional Tool for Phase Segmentation in Electron Backscatter Diffraction N2 - The advent of simultaneous energy dispersive X-ray spectroscopy (EDS) data collection has vastly improved the phase separation capabilities for electron backscatter diffraction (EBSD) mapping. A major problem remains, however, in distinguishing between multiple cubic phases in a specimen, especially when the compositions of the phases are similar or their particle sizes are small because the EDS interaction volume is much larger than that of EBSD, and the EDS spectra collected during spatial mapping are generally noisy due to time limitations and the need to minimize sample drift. The backscatter electron (BSE) signal is very sensitive to the local composition due to its atomic number (Z) dependence. BSE imaging is investigated as a complimentary tool to EDS to assist phase segmentation and identification in EBSD through examination of specimens of meteorite, Cu dross, and steel oxidation layers. The results demonstrate that the simultaneous acquisition of EBSD patterns, EDS spectra, and the BSE signal can provide new potential for advancing multiphase material characterization in the scanning electron microscope. KW - Electron backscatter diffraction KW - Energy dispersive x-ray spectroscopy KW - Scanning electron microscopy KW - Multiphase microstructure KW - Phase identification KW - Backscattered electron imaging KW - Meteorite KW - Monte Carlo simulation PY - 2013 U6 - https://doi.org/10.1017/S1431927613000305 VL - 19 IS - 4 SP - 929 EP - 941 AN - OPUS4-37895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -