Automatic idexing of electron-backscatter diffraction patterns

1994 ◽  
Vol 52 ◽  
pp. 598-599
Author(s):  
S. I. Wright
Keyword(s):  
Feature Detection ◽  
Electron Backscatter Diffraction ◽  
Video Camera ◽  
Light Level ◽  
Lattice Orientation ◽  
Low Light ◽  
Diffraction Patterns ◽  
Digital Image Enhancement ◽  
Backscatter Diffraction

A typical Backscatter Kikuchi Diffraction pattern (BKD, also referred to in the literature as an EBSP or a BEKP) is shown in figure 1. Since the bands in the pattern represent planes in the diffracting volume, the lattice orientation can be determined from their geometrical arrangement. The task of correctly orienting a BKD can be broken into two parts: 1) finding the salient features in the pattern (either the diffraction bands or the intersections of the bands) and 2) using these features to determine the lattice orientation. Recent advances in feature detection in BKDs along with methods for digital image enhancement will be described in some detail. The determination of orientation from a set of detected bands (or intersections of bands) will also be discussed.Dingley has demonstrated that lattice orientation can be practically obtained from BKDs by imaging the diffraction patterns using a low light level video camera and indexing the patterns with the aid of an online computer.

Advances in strain measurement using electron-backscatter diffraction in the Scanning Electron Microscope

1994 ◽  
Vol 52 ◽  
pp. 602-603
Author(s):  
D. J. Dingley
Keyword(s):  
Strain Measurement ◽  
Electron Backscatter Diffraction ◽  
Light Level ◽  
Electron Back Scatter Diffraction ◽  
Photographic Film ◽  
Low Light ◽  
Television Camera ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

The technique of electron back scatter diffraction, EBSD, is well established for measurement of crystal orientation in bulk polycrystalline samples. Analytical procedures for determining crystal phase from them have also been established. In addition several papers have been published describing the application of the method for strain measurement. In these latter studies the EBSPs were recorded on photographic film and all measurements made after digitising the patterns and transferring the data to a SEMPER image processing package. Strain measurement was based on determination of the diffuseness of the diffraction pattern. In the present studies analysis was carried out on digitised television images of the diffraction patterns imaged live on a phosphor screen.EBSPs were obtained in a JEOL 6400 SEM fitted with a tungsten filament. The patterns were imaged on a P20/P40 phosphor directly coupled through a coherent fibre optic bundle to a SIT low light level television camera with 700 line resolution.

The Construction of an EBSD Stage for the Electroscan E3 SEM

2000 ◽  
Vol 6 (S2) ◽  
pp. 796-797
Author(s):  
Peter Yurek ◽  
Stuart McKernan ◽  
Kyung-Ho Lee
Keyword(s):  
Electron Backscatter Diffraction ◽  
Light Level ◽  
Environmental Scanning ◽  
Geological Samples ◽  
Low Light ◽  
Insulating Materials ◽  
Computing Power ◽  
Backscatter Diffraction ◽  
Application Specific ◽  
Environmental Sem

With recent advances in computing power and application specific software it has become practical for smaller microcopy labs to either purchase or build a electron backscatter diffraction (EBSD) systems. This system can be used to probe the crystallography and microstructure of many different materials. One set of such materials is geological samples from deep within the earth's crust. In collaboration with the Geology and Geophysics department an EBSD system has been built to function with the Philips Electroscan E3 Environmental Scanning Electron Microscope (ESEM). Using an existing low light level SIT camera, the system was completed with the addition of a phosphor screen and appropriate software and acquisition cards.One main advantage of the ESEM for EBSD is that since it is an environmental SEM samples can be imaged without coating. For insulating materials this is means that the sample can be imaged without coating.

scholarly journals Determination of Local Strains in a Neighborhood of Cracks in a Welded Seam of Ni-Cr-Fe According to the Power Fourier Spectrum of Kikuchi Patterns

2018 ◽  
Vol 19 (4) ◽  
pp. 307-312 ◽  
Author(s):  
M.D. Borcha ◽  
M.S. Solodkyi ◽  
S.V. Balovsyak ◽  
I.M. Fodchuk ◽  
A.R. Kuzmin ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Gaussian Noise ◽  
Fourier Spectrum ◽  
Electron Backscatter Diffraction ◽  
Two Dimensional ◽  
Electron Backscatter ◽  
Diffraction Patterns ◽  
Welded Seam ◽  
Backscatter Diffraction

A discrete two-dimensional Fourier transform and the power Fourier spectrum are used for determination of average strains near cracks in a welded seam of Ni-Cr-Fe alloy. The alignment of Kikuchi images with the help of genetic algorithms and subtraction of white Gaussian noise made it possible to more fully take into account the influence of instrumental factors on the formation of electron backscatter diffraction patterns.

scholarly journals Determination of Crystal Structure from Electron Backscatter Diffraction Patterns

2009 ◽  
Vol 15 (S2) ◽  
pp. 766-767 ◽  
Author(s):  
SI Wright ◽  
DJ Dingley ◽  
MM Nowell
Keyword(s):  
Crystal Structure ◽  
Electron Backscatter Diffraction ◽  
Electron Backscatter ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

Electron backscatter diffraction determination of grain orientation and constituent phases

1999 ◽  
Vol 4 (2) ◽  
pp. 174-174
Author(s):  
Chen Xiaomei ◽  
Liu Jing ◽  
Wang Jianbo ◽  
Zhang Ruikang ◽  
Wang Dahai ◽  
...  
Keyword(s):  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Diffraction Determination ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Application of Electron Backscatter Diffraction for Crystallographic Characterization of Tin Whiskers

2012 ◽  
Vol 18 (4) ◽  
pp. 876-884 ◽  
Author(s):  
Joseph R. Michael ◽  
Bonnie B. McKenzie ◽  
Donald F. Susan
Keyword(s):  
Electron Backscatter Diffraction ◽  
Growth Direction ◽  
Tin Whiskers ◽  
Physical Growth ◽  
Final Choice ◽  
Advantages And Disadvantages ◽  
Electron Backscatter ◽  
Backscatter Diffraction

AbstractUnderstanding the growth of whiskers or high aspect ratio features on substrates can be aided when the crystallography of the feature is known. This study has evaluated three methods that utilize electron backscatter diffraction (EBSD) for the determination of the crystallographic growth direction of an individual whisker. EBSD has traditionally been a technique applied to planar, polished samples, and thus the use of EBSD for out-of-surface features is somewhat more difficult and requires additional steps. One of the methods requires the whiskers to be removed from the substrate resulting in the loss of valuable physical growth relationships between the whisker and the substrate. The other two techniques do not suffer this disadvantage and provide the physical growth information as well as the crystallographic growth directions. The final choice of method depends on the information required. The accuracy and the advantages and disadvantages of each method are discussed.

scholarly journals Deep Neural Network Enabled Space Group Identification in EBSD

2020 ◽  
Vol 26 (3) ◽  
pp. 447-457 ◽  
Author(s):  
Kevin Kaufmann ◽  
Chaoyi Zhu ◽  
Alexander S. Rosengarten ◽  
Kenneth S. Vecchio
Keyword(s):  
Machine Learning ◽  
Electron Backscatter Diffraction ◽  
Group Identification ◽  
Point Group ◽  
Phase Identification ◽  
Space Group ◽  
Multiple Length Scales ◽  
Analysis Technique ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

AbstractElectron backscatter diffraction (EBSD) is one of the primary tools in materials development and analysis. The technique can perform simultaneous analyses at multiple length scales, providing local sub-micron information mapped globally to centimeter scale. Recently, a series of technological revolutions simultaneously increased diffraction pattern quality and collection rate. After collection, current EBSD pattern indexing techniques (whether Hough-based or dictionary pattern matching based) are capable of reliably differentiating between a “user selected” set of phases, if those phases contain sufficiently different crystal structures. EBSD is currently less well suited for the problem of phase identification where the phases in the sample are unknown. A pattern analysis technique capable of phase identification, utilizing the information-rich diffraction patterns potentially coupled with other data, such as EDS-derived chemistry, would enable EBSD to become a high-throughput technique replacing many slower (X-ray diffraction) or more expensive (neutron diffraction) methods. We utilize a machine learning technique to develop a general methodology for the space group classification of diffraction patterns; this is demonstrated within the $\lpar 4/m\comma \;\bar{3}\comma \;\;2/m\rpar$ point group. We evaluate the machine learning algorithm's performance in real-world situations using materials outside the training set, simultaneously elucidating the role of atomic scattering factors, orientation, and pattern quality on classification accuracy.

scholarly journals Crystal orientation and detector distance effects on resolving pseudosymmetry by electron backscatter diffraction

2021 ◽  
Vol 54 (2) ◽  
pp. 513-522
Author(s):  
Edward L. Pang ◽  
Christopher A. Schuh
Keyword(s):  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Detector Distance ◽  
Recent Emergence ◽  
Distance Effects ◽  
Electron Backscatter ◽  
Sample Position ◽  
Position And Orientation ◽  
Diffraction Patterns ◽  
Backscatter Diffraction

Accurately indexing pseudosymmetric materials has long proven challenging for electron backscatter diffraction. The recent emergence of intensity-based indexing approaches promises an enhanced ability to resolve pseudosymmetry compared with traditional Hough-based indexing approaches. However, little work has been done to understand the effects of sample position and orientation on the ability to resolve pseudosymmetry, especially for intensity-based indexing approaches. Thus, in this work the effects of crystal orientation and detector distance in a model tetragonal ZrO2 (c/a = 1.0185) material are quantitatively investigated. The orientations that are easiest and most difficult to correctly index are identified, the effect of detector distance on indexing confidence is characterized, and these trends are analyzed on the basis of the appearance of specific zone axes in the diffraction patterns. The findings also point to the clear benefit of shorter detector distances for resolving pseudosymmetry using intensity-based indexing approaches.

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