HR-EBSD, cross-correlation, noise, binning, compression, simulated electron backscatter diffraction
Studies of dislocation density evolution are fundamental to improved understanding in various areas of deformation mechanics. Recent advances in cross-correlation techniques, applied to EBSD data have particularly shed light on geometrically necessary dislocation (GND) behavior. However, the framework is relatively computationally expensive – patterns are typically saved from the EBSD scan and analyzed offline. A better understanding of the impact of EBSD pattern degradation, such as binning, compression, and various forms of noise, is vital to enable optimization of rapid and low cost GND analysis. This paper tackles the problem by setting up a set of simulated patterns that mimic real patterns corresponding to a known GND field. The patterns are subsequently degraded in terms of resolution and noise, and the GND densities calculated from the degraded patterns using cross-correlation ESBD are compared with the known values. Some confirmation of validity of the numerical degradation of patterns by considering real pattern degradation is also undertaken. The results demonstrate that the EBSD technique is not particularly sensitive to lower levels of binning and image compression, but the precision is sensitive to Poisson type noise. Some insight is also gained concerning effects of mixed patterns at a grain boundary on measured GND content.
Original Publication Citation
Hansen, Landon T., et al. "Influence of Noise-Generating Factors on Cross-Correlation Electron Backscatter Diffraction (EBSD) Measurement of Geometrically Necessary Dislocations (GNDs)." Microscopy and Microanalysis (2017): 1-12.
BYU ScholarsArchive Citation
Fullwood, David T.; Hansen, Landon; Jackson, Brian; Wright, Stewart I.; Graef, Marc De; Homer, Eric Richards; and Wagoner, Robert, "Influence of Noise Generating Factors on Cross Correlation EBSD Measurement of GNDs" (2017). All Faculty Publications. 1867.
Microscopy and Microanalysis
Ira A. Fulton College of Engineering and Technology
The final published version can be found via: DOI: https://doi.org/10.1017/S1431927617000204.
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