TY - JOUR A1 - Abou-Ras, D. A1 - Gibmeier, J. A1 - Nolze, Gert A1 - Gholinia, A. A1 - Konijnenberg, P. T1 - On the capability of revealing the pseudosymmetry of the chalcopyrite-type crystal structure JF - Crystal Research and Technology N2 - The tetragonal crystal- structure type of chalcopyrites (chemical formula AIBIIICVI2) is a superstructure of sphalerite type. The c/a ratio differs generally from the ideal value 2, i.e., the crystal structure is pseudocubically distorted. For CuInSe2 and CuGaSe2 thin films, simulations demonstrate that it is theoretically possible to reveal the tetragonality in electron backscatter-diffraction (EBSD) patterns for CuGaSe2, whereas it may not be possible for CuInSe2. EBSD experiments on CuGaSe2 thin films using the ”Advanced Fit” band-detection method show that it is possible to extract accurate misorientation-angle distributions from the CuGaSe2 thin film. Pole figures revealing the texture of the CuGaSe2 thin film are shown, which agree well with X-ray texture measurements from the same layer. KW - Pseudosymmetry KW - Chalcopyrite KW - Electron backscatter diffraction KW - Pattern simulation KW - Pattern matching KW - Sphalerite PY - 2008 DO - https://doi.org/10.1002/crat.200711082 VL - 43 IS - 3 SP - 234 EP - 239 PB - WILEY-VCH AN - OPUS4-38003 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. I. A1 - Nolze, Gert T1 - Investigation of the competitive grain growth during solidification of single crystals of nickel-based superalloys JF - Crystallography Reports N2 - The competitive growth of columnar grains in a single-grain selector, which is used for directional solidification of single-crystal blades from nickel-based superalloys, has been investigated by electron backscattered diffraction and local X-ray diffraction analysis. It has been found that the competitive grain growth in a starter block is determined by the crystallographic factor: rapidly growing grains with the axial orientation close to the [001] direction dominate in this part of the casting. For the competitive grain growth in a helicoidal separator, the geometric factor (the position of a grain at the input of the separator) is also important. The results obtained suggest that an appropriate geometry of the single-grain selector was chosen. In addition, the distribution of the orientations of columnar grains obtained by electron backscattered diffraction, can be used for approximate estimation of the yield of suitable (i.e., with the deviation of the axial orientation from the [001] direction within a specified tolerance) single-crystal blades. KW - Electron backscatter diffraction KW - Single crystal KW - Growth competition KW - Nickel alloy PY - 2006 DO - https://doi.org/10.1134/S1063774506040298 SN - 1063-7745 SN - 1562-689X VL - 51 IS - 4 SP - 710 EP - 714 AN - OPUS4-38028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epishin, A. I. A1 - Petrushin, N. V. A1 - Link, T. A1 - Nolze, Gert A1 - Loshchinin, Yu. V. A1 - Gerstein, G. T1 - Thermal stability of the structure of a heat-resistant cobalt alloy hardened with intermetallic γ'-phase precipitates JF - Russian Metallurgy N2 - The thermal stability of the microstructure of a heat-resistant cobalt alloy, which consists of a γ solid solution strengthened with γ'-phase precipitates, has been studied. The temperature behavior of the dissolution of the hardening γ' phase and the kinetics of its coarsening at 700 and 800°C have been determined. It is found that, during prolonged annealing at 800°C, the γ' → β phase transformation occurs. KW - Superalloy KW - Microstructure KW - Hardening KW - Electron backscatter diffraction KW - TEM PY - 2016 DO - https://doi.org/10.1134/S0036029516040078 SN - 0036-0295 VL - 2016 IS - 4 SP - 286 EP - 291 PB - Pleiades Publishing AN - OPUS4-37768 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Glowacka, A. A1 - Nolze, Gert A1 - Swiatnicki, W. A. T1 - EBSD study of corrosion fatigue of austenitic-ferritic steel JF - Archives of Metallurgy and Materials N2 - Fatigue crack propagation investigations have been performed in austenitic-ferritic duplex stainless steel H22N5M3 in air and during hydrogen charging, using various frequencies of loading. Strong differences of crack propagation velocity depending on the test conditions were noticed. Lower frequency with applied hydrogen charging led to the huge increase of crack propagation velocity compared to the tests performed in air. To understand such a behaviour in each case and characterize crack mode, the samples were observed using electron back-scattered diffraction (EBSD). It was shown that in air, the fatigue crack propagation involved plastic deformation and the resulting cracks had ductile character. The presence of hydrogen led to more brittle mode of cracking. This effect was also connected with frequency of loading: lower frequency, which assured longer time for hydrogen-crack tip interaction, resulted in the highest crack propagation velocity and the brittle cracking mode with lower amount of plastic deformation. The performed observations indicated that the path of the crack went mostly transgranularly through both austenite and ferrite phases. Phase and grain boundaries were not the preferred paths for crack propagation. KW - Hydrogen KW - Embrittlement KW - Electron backscatter diffraction KW - Steel PY - 2006 SN - 1733-3490 SN - 0004-0770 SN - 0860-7052 VL - 51 IS - 1 SP - 7 EP - 10 AN - OPUS4-38029 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Glowacka, A. A1 - Wozniak, M. J. A1 - Nolze, Gert A1 - Swiatnicki, W. A. T1 - Hydrogen induced phase transformations in austenitic-ferritic steel JF - Solid State Phenomena N2 - The hydrogen influence on the microstructure of the austenitic-ferritic Cr22-Ni5-Mo3 stainless steel was investigated. Cathodic hydrogen charging was performed electrochemically from aqueous solution of 0.1M H2SO4 with hydrogen entry promoter addition. The aim of this study was to reveal microstructural changes appearing during the hydrogen charging and particularly to clarify the occurrence of phase transformations induced by hydrogen. The specific changes in both phases of steel were observed. In the ferritic phase, strong increase of dislocation density was noticed. Longer time of hydrogen charging leaded also to the strips and twin plates formation in ferrite phase. In the austenitic phase, the generation of stacking faults, followed by the formation of α' martensite was remarked. KW - Steel KW - Hydrogen KW - Embrittlement KW - Electron backscatter diffraction KW - SEM PY - 2006 DO - https://doi.org/10.4028/www.scientific.net/SSP.112.133 SN - 1662-9779 VL - 112 SP - 133 EP - 140 AN - OPUS4-38031 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martin, S. A1 - Walnsch, A. A1 - Nolze, Gert A1 - Leineweber, A. A1 - Léaux, F. A1 - Scheuerlein, C. T1 - The crystal structure of (Nb0.75Cu0.25)Sn-2 in the Cu-Nb-Sn system JF - Intermetallics N2 - During the processing of superconducting Nb3Sn wire, several intermediate intermetallic phases including a previously encountered Cu-Nb-Sn phase show up. The yet unknown crystal structure of this phase is now identified by a combination of different experimental techniques and database search to be of the hexagonal NiMg2 type with a proposed composition of about (Nb0.75Cu0.25)Sn2. The structure determination started from an evaluation of the lattice parameters from EBSD Kikuchi patterns from quenched material suggesting hexagonal or orthorhombic symmetry. A database search then led to the hexagonal NiMg2 type structure, the presence of which was confirmed by a Rietveld analysis on the basis of high energy synchrotron X-ray powder diffraction data. Assuming a partial substitution of Nb in orthorhombic NbSn2 by Cu, the change of the valence electron concentration provokes a structural transformation from the CuMg2 type for NbSn2 to the NiMg2 type for (Nb0.75Cu0.25)Sn2. In the previous literature the (Nb0.75Cu0.25)Sn2 phase described here has occasionally been referred to as Nausite. KW - Electron backscatter diffraction KW - X-ray diffraction KW - Intermetallic compound KW - Structure solution KW - Superconductor PY - 2017 DO - https://doi.org/10.1016/j.intermet.2016.09.008 SN - 0966-9795 SN - 1879-0216 VL - 80 SP - 16 EP - 21 PB - Elsevier Ltd. AN - OPUS4-37874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nolze, Gert T1 - Computational Advances N2 - The EBSD signal provides more information than the used Kikuchi pattern. The presentation discusses several parts of the detected signal and how they can be interpreted. T2 - EBSD 2014 CY - Pittsburgh, Pennsylvania, USA DA - 17.06.2014 KW - Electron backscatter diffraction KW - Simulation KW - Kikuchi pattern KW - Magnetite KW - Maghemite KW - Hematite PY - 2014 AN - OPUS4-37899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nolze, Gert T1 - Microstructure characterization of the Treysa meteorite N2 - Microstructure descripton of heat-affected zone, fusion crust and main metal of the Treysa iron using scanning electron microscopy, EBSD and EDS. T2 - 8. Deutsches Meteoriten Kolloquium, CY - Zella Willingshausen, Germany DA - 02.04.2016 KW - Electron backscatter diffraction KW - EDX KW - Light microscopy KW - Microstructure KW - Oxidation PY - 2016 DO - https://doi.org/10.13140/RG.2.1.3387.8161 AN - OPUS4-37769 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert T1 - Irrational orientation relationship derived from rational orientation relationships using EBSD data JF - Crystal Research and Technology N2 - The determination of the orientation relationship (OR) between α-Fe matrix (bcc) and γ-Fe precipitates (fcc) is discussed using orientation data collected by electron backscatter diffraction (EBSD). The comparatively low accuracy of EBSD is compensated by the high number of measurements what allows a general statement regarding to the mean OR existing in a sample. The representation and discussion is realized on a part of the Bain zone in a {001} pole figure. A discussion of some selected rational OR which are commonly used for the phase boundary characterization between α and γ shows that the pole figures describing a transformation from γ → α are different to those for α → γ. A technique is proposed based on at least three misorientation angles between the experimental OR to the rational OR's as reference. For the misorientation angle distribution a refinement is applied to extract the mean values. They are used to detect the mean OR, what is also possible for only a few or even a single precipitate if the number of measurements describing the phase boundary is sufficiently high. KW - Orientation mapping KW - Orientation relationship KW - Electron backscatter diffraction KW - Kurdjumov-Sachs KW - Nishiyama-Wassermann KW - Misorientation PY - 2008 DO - https://doi.org/10.1002/crat.200711058 VL - 43 IS - 1 SP - 61 EP - 73 PB - WILEY-VCH AN - OPUS4-38009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nolze, Gert T1 - Interphase boundary characterization in duplex steel and iron meteorites using EBSD technique JF - Archives of Metallurgy and Materials N2 - The properties of materials are mainly described by the orientation distribution of the crystalline phases in a material. Beside the so considered anisotropy also the grain as well as phase boundaries are of extreme importance for a whole string of properties, e.g. the strength of a material. On the example of the interface between fcc and bcc iron the discovered and derived models are discussed. Although the common models are based on the crystal lattice description, the atomic configuration on the interface is analysed. Since experimentally a wide spread of orientations data appears the consideration of the frequency distribution is proposed to find at least the main orientation relationship between fcc and bcc. High-indexed pole figures as well as the Euler subspace are introduced in order to increase the accuracy and to compare different measurements. For the sake of simplicity EBSD measurements on iron meteorites are used since they commonly consist of large fcc single crystals which transformed to a low and very specific number of bcc grains. In special cases the described procedure could also be used for steels. KW - Orientation relationships KW - Electron backscatter diffraction KW - Steel KW - Iron meteorites KW - Kurdjumov-Sachs KW - Nishiyama-Wassermann PY - 2006 SN - 1733-3490 SN - 0004-0770 SN - 0860-7052 VL - 51 IS - 1 SP - 15 EP - 22 AN - OPUS4-38030 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -