TY - JOUR A1 - Nolze, Gert A1 - Winkelmann, A. T1 - About the reliability of EBSD measurements: Data enhancement N2 - An extensive set of information about the diffracting volume is carried by EBSD patterns: the crystal lattice, the reciprocal lattice, the crystal structure, the crystal symmetry, the mean periodic number of the diffracting phase, the source point from where it has been projected (projection centre), the crystal orientation, the sample topography (local tilt), the (preparation) quality of defect density of the crystal, and possible pattern overlaps. Some of this information is used regularly in conventional EBSD analyses software while others are still waiting for a more widespread application. Despite the wealth of information available, the accuracy and precision of the data that are presently extracted from conventional EBSD patterns are often well below the actual physical limits. Using a selection of example applications, we will demonstrate the gain in angular resolution possible using relatively low-resolution patterns of approximately 20k pixels in combination with pattern matching (PM) approaches. In this way, fine details in a microstructure can be revealed which would otherwise be hidden in the orientation noise. KW - EBSD KW - Orientation precision KW - Disorientation KW - Grain boundary KW - Phase transformation PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521618 DO - https://doi.org/10.1088/1757-899X/891/1/012018 VL - 891 SP - 012018 PB - IOP Science AN - OPUS4-52161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cios, G. A1 - Nolze, Gert A1 - Winkelmann, A. A1 - Tokarski, T. A1 - Hielscher, R. A1 - Strzalka, R. A1 - Buganski, I. A1 - Wolny, J. A1 - Bala, P. T1 - Approximant-based orientation determination of quasicrystals using electron backscatter diffraction N2 - Orientation mapping of quasicrystalline materials is demonstrated using crystalline approximant structures in the technique of electron backscatter diffraction (EBSD). The approximant-based orientations are symmetrised according to the rotational point group of the quasicrystal, including the visualization of orientation maps using proper colour keys for quasicrystal symmetries. Alternatively, approximant-based orientation data can also be treated using pseudosymmetry post-processing options in the EBSD system software, which enables basic grain size estimations. Approximant-based orientation analyses are demonstrated for icosahedral and decagonal quasicrystals. KW - EBSD KW - Quasicrystal KW - Approximant KW - Chrystal orientation KW - Data processing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514221 DO - https://doi.org/10.1016/j.ultramic.2020.113093 VL - 218 SP - 113093 PB - Elsevier B.V. AN - OPUS4-51422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nolze, Gert T1 - CALM down: Identifying unknown phases N2 - CALM is software for determining the Bravais lattice type and the resulting lattice parameters from a single Kikuchi pattern. It requires the definition of 4 bands and a single bandwidth from which all other band positions as well as bandwidths are derived. For band detection, it uses the Funk transform, which allows detection of twice as many bands as usual. CALM works for any symmetry and requires low-noise patterns of at least 320x240 pixels. The resulting errors are <2% even for such small patterns, assuming good quality. The relative errors are <0.5%. However, this requires a projection centre position best derived from a sample of a cubic phase in CALM. However, this must have been recorded under identical conditions. Hundreds of Kikuchi patterns of phases with different symmetries were examined. T2 - Chemnitz MTEX Workshop 2021 CY - Online meeting DA - 08.03.2021 KW - EBSD KW - Gitterkonstanten KW - Phasenidentifikation PY - 2021 AN - OPUS4-52345 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Svetlov, I. L. A1 - Epishin, A. I. A1 - Petrushin, N. V. A1 - Gerstein, G. A1 - Nolze, Gert A1 - Maier, H. J. T1 - Creep of Directionally Solidified Eutectics Ni/Ni3 Al–NbC under Thermal Cycling N2 - A nickel-based eutectic alloy with a γ/γ'-NbC structure was directionally solidified with a planar front. The specimens were tested for creep under sawtooth thermal cycling in the temperature range from 600 to 1100°C. It has been established that the lifetime under the conditions of thermal cycling is about five times shorter than it is predicted by the linear damage accumulation rule on the basis of results of isothermal creep tests. Faster creep under thermal cycling is caused by the rapid coarsening of the γ/γ' microstructure due to the periodic partial dissolution and reprecipitation of the γ' phase in heating and cooling half-cycles. KW - High temperature nickel-based eutectic alloys KW - γ/γ' matrix KW - Carbide phase NbC KW - In-situ composites KW - Creep under thermal cycling PY - 2022 DO - https://doi.org/10.1134/S2075113322040347 SN - 2075-1133 VL - 13 IS - 4 SP - 1099 EP - 1108 PB - Springer Science + Business Media CY - Dordrecht AN - OPUS4-55163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert A1 - Tokarski, T. A1 - Rychlowski, L. A1 - Cios, G. A1 - Winkelmann, A. T1 - Crystallographic analysis of the lattice metric (CALM) from single electron backscatter diffraction or transmission Kikuchi diffraction patterns N2 - A new software is presented for the determination of crystal lattice parameters from the positions and widths of Kikuchi bands in a diffraction pattern. Starting with a single wide-angle Kikuchi pattern of arbitrary resolution and unknown phase, the traces of all visibly diffracting lattice planes are manually derived from four initial Kikuchi band traces via an intuitive graphical user interface. A single Kikuchi bandwidth is then used as reference to scale all reciprocal lattice point distances. Kikuchi band detection, via a filtered Funk transformation, and simultaneous display of the band intensity profile helps users to select band positions and widths. Bandwidths are calculated using the first derivative of the band profiles as excess-deficiency effects have minimal influence. From the reciprocal lattice, the metrics of possible Bravais lattice types are derived for all crystal systems. The measured lattice parameters achieve a precision of <1%, even for good quality Kikuchi diffraction patterns of 400 x 300 pixels. This band-edge detection approach has been validated on several hundred experimental diffraction patterns from phases of different symmetries and random orientations. It produces a systematic lattice parameter offset of up to ±4%, which appears to scale with the mean atomic number or the backscatter coefficient. KW - Electron backscatter diffraction KW - Kikuchi patterns KW - Lattice parameters KW - Radon transform PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527076 DO - https://doi.org/10.1107/S1600576721004210 SN - 1600-5767 VL - 54 IS - Pt 3 SP - 1012 EP - 1022 AN - OPUS4-52707 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 - Jany, B. R. A1 - Bala, P. T1 - EBSD and TKD analyses using inverted contrast Kikuchi diffraction patterns and alternative measurement geometries N2 - Electron backscatter diffraction (EBSD) patterns can exhibit Kikuchi bands with inverted contrast due to anomalous absorption. This can be observed, for example, on samples with nanoscale topography, in case of a low tilt backscattering geometry, or for transmission Kikuchi diffraction (TKD) on thicker samples. Three examples are discussed where contrast-inverted physics-based simulated master patterns have been applied to find the correct crystal orientation. As first EBSD example, self-assembled gold nanostructures made of Au fcc and Au hcp phases on single-crystal germanium were investigated. Gold covered about 12% of the mapped area, with only two thirds being successfully interpreted using standard Hough-based indexing. The remaining third was solved by brute force indexing using a contrast-inverted master pattern. The second EBSD example deals with maps collected at a non-tilted surface instead of the commonly used 70◦ tilted one. As TKD example, a jet-polished foil made of duplex stainless steel 2205 was examined. The thin part close to the hole edge producing normal-contrast patterns were standard indexed. The areas of the foil that become thicker with increasing distance from the edge of the hole produce contrast-inverted patterns. They covered three times the evaluable area and were successfully processed using the contrast-inverted master pattern. In the last example, inverted patterns collected at a non-tiled sample were mathematically inverted to normal contrast, and Hough/Radon-based indexing was successfully applied. KW - EBSD KW - TKD KW - Contrast inversion KW - Topography KW - Kikuchi diffraction PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613862 VL - 267 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-61386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Winkelmann, A. A1 - Cios, G. A1 - Tokarski, T. A1 - Nolze, Gert A1 - Hielscher, R. A1 - Koziel, T. T1 - EBSD orientation analysis based on experimental Kikuchi reference patterns N2 - Orientation determination does not necessarily require complete knowledge of the local atomic arrangement in a crystalline phase. We present a method for microstructural phase discrimination and orientation analysis of phases for which there is only limited crystallographic information available. In this method, experimental Kikuchi diffraction patterns are utilized to generate a self-consistent master reference for use in the technique of Electron Backscatter Diffraction (EBSD). The experimentally derived master data serves as an application-specific reference in EBSD pattern matching approaches. As application examples, we map the locally varying orientations in samples of icosahedral quasicrystals observed in a Ti40Zr40Ni20 alloy, and we analyse AlNiCo decagonal quasicrystals. KW - EBSD KW - Quasicrystal KW - Crystal orientation KW - Pattern matching PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507611 DO - https://doi.org/10.1016/j.actamat.2020.01.053 VL - 188 SP - 376 EP - 385 PB - Elsevier Ltd. AN - OPUS4-50761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stephan-Scherb, Christiane A1 - Menneken, Martina A1 - Weber, Kathrin A1 - Agudo Jácome, Leonardo A1 - Nolze, Gert T1 - Elucidation of orientation relations between Fe-Cr alloys and corrosionproducts after high temperature SO2 corrosion N2 - The early stages of corrosion of Fe-Cr-model alloys (2 and 9 % Cr) were investigated after exposure at 650 °C in0.5 % SO2containing gas by electron backscattered diffraction (EBSD) and transmission electron microscopy(TEM). The impact of the grain orientation of the base alloy on the orientation relations of the corrosion productsis presented. After 2 min–5 min exposure the formation of a multi-layered corrosion zone was discovered. Aclear orientation relationship between ferrite and the (Fe,Cr)3O4 spinel could be demonstrated. The obtainedresults show the importance of the grain orientation on oxidation resistance. KW - Iron KW - TEM KW - SEM KW - High temperature corrosion PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508911 DO - https://doi.org/10.1016/j.corsci.2020.108809 VL - 174 SP - 1 EP - 11 PB - Elsevier AN - OPUS4-50891 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Treninkov, I. A. A1 - Petrushin, N. V. A1 - Epishin, A. I. A1 - Svetlov, I. L. A1 - Nolze, Gert A1 - Elyutin, E. S. T1 - Experimental Determination of Temperature Dependence of Structural–Phase Parameters of Nickel-Based Superalloy N2 - The temperature dependences of the periods of the crystal lattices of the γ and γ' phases, their dimensional mismatch (misfit), and volume fraction of the γ' phase of an experimental single-crystal hightemperature nickel-based alloy have been determined by X-ray diffraction analysis in the temperature range of 18–1150°C. The temperature ranges in which intense changes in the structural and phase characteristics of the alloy under study take place have been determined. KW - X-ray diffraction analysis KW - High temperatures KW - Nickel-based superalloys KW - Single crystal KW - Crystal lattice period PY - 2022 DO - https://doi.org/10.1134/s2075113322010373 SN - 2075-1133 VL - 13 IS - 1 SP - 171 EP - 178 PB - Springer Science + Business Media CY - Dordrecht AN - OPUS4-54466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tokarski, T. A1 - Nolze, Gert T1 - Exploring Unconventional Uses of Kikuchi Pattern Analysis N2 - The characterization of really unknown phases typically uses 70 to 150 reflectors for lattice metric calculation. The determination of the lattice parameters follows with 4% accuracy. Including a Z correction up to 1% can be reached. The precision of the lattice parameters ratios (a:b:c) is, however, better than 0.1%. T2 - Oxford Users Meeting 2024 CY - Krakow, Poland DA - 14.05.2024 KW - EBSD KW - Kikuchi KW - Lattice parameters KW - Ratio refinement PY - 2024 AN - OPUS4-60086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -