scholarly journals Refined Calibration Model for Improving the Orientation Precision of Electron Backscatter Diffraction Maps

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2816 ◽  
Author(s):  
Aimo Winkelmann ◽  
Gert Nolze ◽  
Grzegorz Cios ◽  
Tomasz Tokarski ◽  
Piotr Bała
Keyword(s):  
Crystalline Silicon ◽  
Electron Backscatter Diffraction ◽  
Projective Transformation ◽  
Least Square ◽  
Transformation Model ◽  
Polycrystalline Materials ◽  
Calibration Model ◽  
Electron Backscatter ◽  
Projection Center ◽  
Backscatter Diffraction

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.

Application of Electron Backscatter Diffraction to Grain Boundaries

2010 ◽  
Vol 160 ◽  
pp. 39-46 ◽  
Author(s):  
Valerie Randle
Keyword(s):  
Grain Boundary ◽  
Electron Backscatter Diffraction ◽  
Experimental Methodology ◽  
Polycrystalline Materials ◽  
Grain Boundary Engineering ◽  
Network Characteristics ◽  
Grain Boundary Plane ◽  
Electron Backscatter ◽  
Measurement Strategies ◽  
Backscatter Diffraction

The technique of electron backscatter diffraction (EBSD) is ideal for the characterisation of grain boundary networks in polycrystalline materials. In recent years the experimental methodology has evolved to meet the needs of the research community. For example, the capabilities of EBSD have been instrumental in driving forward the topic of ‘grain boundary engineering’. In this paper the current capabilities of EBSD for grain boundary characterisation will be reviewed and illustrated by examples. Topics are measurement strategies based on misorientation statistics, determination of grain boundary plane distributions and grain boundary network characteristics.

Analysis of Multiphase Materials Using Electron Backscatter Diffraction

1997 ◽  
Vol 3 (S2) ◽  
pp. 561-562
Author(s):  
S.I. Wright ◽  
D.P. Field
Keyword(s):  
Crystallographic Orientation ◽  
Electron Backscatter Diffraction ◽  
Computer Control ◽  
Orientation Imaging Microscopy ◽  
Spatial Arrangement ◽  
Polycrystalline Materials ◽  
Orientation Data ◽  
Topological Features ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Image analysis techniques coupled with crystallography computer codes have been used to index electron backscatter diffraction patterns (EBSPs). The ability to automatically obtain the crystallographic orientation from EBSPs coupled with computer control of the electron beam (or stage) in a scanning electron microscope (SEM) provides a much more complete description of the spatial distribution of crystallographic orientation in polycrystalline materials than has been previously attainable using conventional metallography techniques. Orientation data obtained using this technique can be used to form images reflecting the spatial arrangement of crystallographic orientation in a microstructure. Such images enable the topological features of a microstructure to be linked with the orientation characteristics. The formation of these images, as well as the data collection technique, is sometimes termed Orientation Imaging Microscopy (OIM). The utility of this technique for exploring the property/structure relationship in polycrystalline material has been demonstrated by numerous researchers. However, as yet, this technique has almost exclusively been applied to single phase materials.

Electron Backscatter Diffraction

2019 ◽  
Author(s):  
David P. Field ◽  
Mukul Kumar
Keyword(s):  
Electron Microscope ◽  
Friction Stir Welding ◽  
Integrated Circuit ◽  
Electron Backscatter Diffraction ◽  
Local Information ◽  
Polycrystalline Materials ◽  
Friction Stir ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Scanning Electron

Electron backscatter diffraction (EBSD) is a scanning electron microscope (SEM) based technique that is used to obtain local information on the crystallographic character of bulk crystalline and polycrystalline materials. Topics discussed in this article include: EBSD system overview, multiphase analysis, and application to aluminum integrated circuit interconnects, dislocation structure analysis, analysis of grain boundary networks, and application to friction stir welding of aluminum alloys.

Grain Subdivision of a Nb Polycrystal Deformed by Successive Compression Tests

2010 ◽  
Vol 667-669 ◽  
pp. 373-378
Author(s):  
Liang Zhu ◽  
Hugo Ricardo Zschommler Sandim ◽  
Marc Seefeldt ◽  
Bert Verlinden
Keyword(s):  
Grain Boundary ◽  
Grain Orientation ◽  
Electron Backscatter Diffraction ◽  
Small Strain ◽  
The Other ◽  
Polycrystalline Materials ◽  
Historical Evolution ◽  
Compression Tests ◽  
Electron Backscatter ◽  
Backscatter Diffraction

To understand and model grain refinement in severe plastic deformation, some analysis of Nb single crystals has been carried out in previous work. To bridge the gap with normal polycrystalline materials, supplementary experiments on large polycrystals, deformed at moderate strains appear to be necessary to explain the grain subdivision step by step. In the present work, successive uniaxial compression tests have been carried out on a large grained Niobium polycrystal up to height reductions of 30% with small strain increments. Electron backscatter diffraction (EBSD) analysis was done after each compression step to characterize the evolution of orientation and microstructures. It is observed that a “rotation front” forms inside the grain and moves with increasing strain from one side to the other side of the grain. In one grain, this process results in a grain boundary affected zone in the vicinity of the grain boundary. Both static orientation evolution inside the grain and historical evolution of the average orientation have been studied, which indicates that the grain orientation rotates around one of the (110) poles at low strain.

A Dictionary Approach to Electron Backscatter Diffraction Indexing

2015 ◽  
Vol 21 (3) ◽  
pp. 739-752 ◽  
Author(s):  
Yu H. Chen ◽  
Se Un Park ◽  
Dennis Wei ◽  
Greg Newstadt ◽  
Michael A. Jackson ◽  
...  
Keyword(s):  
Electron Backscatter Diffraction ◽  
Orientation Distribution ◽  
Polycrystalline Materials ◽  
Dictionary Matching ◽  
Binary Decision Tree ◽  
Electron Backscatter ◽  
Dense Grid ◽  
The Mean ◽  
Von Mises ◽  
Backscatter Diffraction

AbstractWe propose a framework for indexing of grain and subgrain structures in electron backscatter diffraction patterns of polycrystalline materials. We discretize the domain of a dynamical forward model onto a dense grid of orientations, producing a dictionary of patterns. For each measured pattern, we identify the most similar patterns in the dictionary, and identify boundaries, detect anomalies, and index crystal orientations. The statistical distribution of these closest matches is used in an unsupervised binary decision tree (DT) classifier to identify grain boundaries and anomalous regions. The DT classifies a pattern as an anomaly if it has an abnormally low similarity to any pattern in the dictionary. It classifies a pixel as being near a grain boundary if the highly ranked patterns in the dictionary differ significantly over the pixel’s neighborhood. Indexing is accomplished by computing the mean orientation of the closest matches to each pattern. The mean orientation is estimated using a maximum likelihood approach that models the orientation distribution as a mixture of Von Mises–Fisher distributions over the quaternionic three sphere. The proposed dictionary matching approach permits segmentation, anomaly detection, and indexing to be performed in a unified manner with the additional benefit of uncertainty quantification.

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