Anmelden

Open Access

  • Startseite
  • Suchen
  • Browsen
  • Veröffentlichen
  • Hilfe

Filtern

Autor

  • Nolze, Gert (7)
  • Winkelmann, A. (7)
  • Cios, G. (5)
  • Tokarski, T. (5)
  • Bala, P. (2)
  • Britton, T. B. (2)
  • Hielscher, R. (2)
  • Buganski, I. (1)
  • Koziel, T. (1)
  • Strzalka, R. (1)
+ weitere

Erscheinungsjahr

  • 2020 (4)
  • 2019 (2)
  • 2018 (1)

Dokumenttyp

  • Zeitschriftenartikel (6)
  • Forschungsdatensatz (1)

Referierte Publikation

  • ja (6)
  • nein (1)

Schlagworte

  • EBSD (6)
  • Electron backscatter diffraction (2)
  • Electron energy (2)
  • Energy distribution (2)
  • Kikuchi pattern (2)
  • Quasicrystal (2)
  • Scanning electron microscopy (2)
  • Simulation (2)
  • Angle measurement (1)
  • Approximant (1)
+ weitere

Organisationseinheit der BAM

  • 5 Werkstofftechnik (7)
  • 5.1 Materialographie, Fraktographie und Alterung technischer Werkstoffe (7)

7 Treffer

  • 1 bis 7
  • CSV
  • RIS
  • 10
  • 20
  • 50
  • 100

Sortieren nach

  • Jahr
  • Jahr
  • Titel
  • Titel
  • Autor
  • Autor
Mapping of local lattice parameter ratios by projective Kikuchi pattern matching (2018)
Winkelmann, A. ; Nolze, Gert ; Cios, G. ; Tokarski, T.
We describe a lattice-based crystallographic approximation for the analysis of distorted crystal structures via Electron Backscatter Diffraction (EBSD) in the scanning electron microscope. EBSD patterns are closely linked to local lattice parameter ratios via Kikuchi bands that indicate geometrical lattice plane projections. Based on the transformation properties of points and lines in the real projective plane, we can obtain continuous estimations of the local lattice distortion based on projectively transformed Kikuchi diffraction simulations for a reference structure. By quantitative image matching to a projective transformation model of the lattice distortion in the full solid angle of possible scattering directions, we enforce a crystallographically consistent approximation in the fitting procedure of distorted simulations to the experimentally observed diffraction patterns. As an application example, we map the locally varying tetragonality in martensite grains of steel.
EBSD Kikuchi Pattern Analysis, Silicon 15kV (2019)
Winkelmann, A. ; Britton, T. B. ; Nolze, Gert
Supplementary data and images for Si EBSD pattern analysis as presented in: A. Winkelmann, T.B. Britton, G. Nolze "Constraints on the effective electron energy spectrum in backscatter Kikuchi diffraction", Physical Review B (2019).
EBSD orientation analysis based on experimental Kikuchi reference patterns (2020)
Winkelmann, A. ; Cios, G. ; Tokarski, T. ; Nolze, Gert ; Hielscher, R. ; Koziel, T.
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.
Refined Calibration Model for Improving the Orientation Precision of Electron Backscatter Diffraction Maps (2020)
Winkelmann, A. ; Nolze, Gert ; Cios, G. ; Tokarski, T. ; Bala, P.
For the precise determination of orientations in polycrystalline materials, electron backscatter diffraction (EBSD) requires a consistent calibration of the diffraction geometry in the scanning electron microscope (SEM). In the present paper, the variation of the projection center for the Kikuchi diffraction patterns which are measured by EBSD is calibrated using a projective transformation model for the SEM beam scan positions on the sample. Based on a full pattern matching approach between simulated and experimental Kikuchi patterns, individual projection center estimates are determined on a subgrid of the EBSD map, from which least-square fits to affine and projective transformations can be obtained. Reference measurements on single-crystalline silicon are used to quantify the orientation errors which result from different calibration models for the variation of the projection center.
Constraints on the effective electron energy spectrum in backscatter Kikuchi diffraction (2019)
Nolze, Gert ; Winkelmann, A. ; Britton, T. B.
Electron backscatter diffraction (EBSD) is a technique to obtain microcrystallographic information from materials by collecting large-angle Kikuchi patterns in the scanning electron microscope (SEM). An important fundamental question concerns the scattering-angle dependent electron energy distribution, which is relevant for the formation of the Kikuchi diffraction patterns. Here we review the existing experimental data and explore the effective energy spectrum that is operative in the generation of backscatter Kikuchi patterns from silicon. We use a full pattern comparison of experimental data with dynamical electron diffraction simulations. Our energy-dependent cross-correlation based pattern matching approach establishes improved constraints on the effective Kikuchi pattern energy spectrum, which is relevant for high-resolution EBSD pattern simulations and their applications.
Approximant-based orientation determination of quasicrystals using electron backscatter diffraction (2020)
Cios, G. ; Nolze, Gert ; Winkelmann, A. ; Tokarski, T. ; Hielscher, R. ; Strzalka, R. ; Buganski, I. ; Wolny, J. ; Bala, P.
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.
Manual measurement of angles in backscattered and transmission Kikuchi diffraction patterns (2020)
Nolze, Gert ; Tokarski, T. ; Cios, G. ; Winkelmann, A.
A historical tool for crystallographic analysis is provided by the Hilton net, which can be used for manually surveying the crystal lattice as it is manifested by the Kikuchi bands in a gnomonic projection. For a quantitative analysis using the Hilton net, the projection centre as the relative position of the signal source with respect to the detector plane needs to be known. Interplanar angles are accessible with a precision and accuracy which is estimated to be ≤0.3o. Angles between any directions, e.g. zone axes, are directly readable. Finally, for the rare case of an unknown projection-centre position, its determination is demonstrated by adapting an old approach developed for photogrammetric applications. It requires the indexing of four zone axes [uvw]i in a backscattered Kikuchi diffraction pattern of a known phase collected under comparable geometric conditions.
  • 1 bis 7

OPUS4 Logo

  • Kontakt
  • Impressum
  • Sitelinks