The effect of pattern overlap on the accuracy of high resolution electron backscatter diffraction measurements

Vivian Tong; Jun Jiang; Angus J Wilkinson; T Ben Britton

doi:10.1016/j.ultramic.2015.04.019

The effect of pattern overlap on the accuracy of high resolution electron backscatter diffraction measurements

Ultramicroscopy. 2015 Aug:155:62-73. doi: 10.1016/j.ultramic.2015.04.019. Epub 2015 Apr 28.

Authors

Vivian Tong¹, Jun Jiang², Angus J Wilkinson³, T Ben Britton²

Affiliations

¹ Department of Materials, Imperial College London, Prince Consort Road, London SW7 2AZ, UK. Electronic address: v.tong13@imperial.ac.uk.
² Department of Materials, Imperial College London, Prince Consort Road, London SW7 2AZ, UK.
³ Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK.

PMID: 25957534
DOI: 10.1016/j.ultramic.2015.04.019

Abstract

High resolution, cross-correlation-based, electron backscatter diffraction (EBSD) measures the variation of elastic strains and lattice rotations from a reference state. Regions near grain boundaries are often of interest but overlap of patterns from the two grains could reduce accuracy of the cross-correlation analysis. To explore this concern, patterns from the interior of two grains have been mixed to simulate the interaction volume crossing a grain boundary so that the effect on the accuracy of the cross correlation results can be tested. It was found that the accuracy of HR-EBSD strain measurements performed in a FEG-SEM on zirconium remains good until the incident beam is less than 18 nm from a grain boundary. A simulated microstructure was used to measure how often pattern overlap occurs at any given EBSD step size, and a simple relation was found linking the probability of overlap with step size.

Keywords: Cross-correlation; Grain boundary; High-resolution EBSD; Pattern overlap.

Publication types

Research Support, Non-U.S. Gov't