Understanding deformation with high angular resolution electron backscatter diffraction (HR-EBSD)

15th European Workshop on Modern Developments and Applications in Microbeam Analysis; 7th Meeting of the International union of Microbeam Analysis Societies

材料科学;物理学

Britton, T.B.^1 ; Hickey, J.L.R.^1

Imperial College London, Department of Materials, Exhibition Road, London

SW7 2AZ, United Kingdom^1

关键词: Angular resolution;    Cross correlations;    Degree of sensitivity;    Electron back scatter diffraction;    High angular resolutions;    Lattice orientations;    Orders of magnitude;    Polycrystalline alloys;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/304/1/012003/pdf
DOI  :  10.1088/1757-899X/304/1/012003

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

High angular resolution electron backscatter diffraction (HR-EBSD) affords an increase in angular resolution, as compared to 'conventional' Hough transform based EBSD, of two orders of magnitude, enabling measurements of relative misorientations of 1 x 10-4rads (∼ 0.006°) and changes in (deviatoric) lattice strain with a precision of 1 x 10-4. This is achieved through direct comparison of two or more diffraction patterns using sophisticated cross-correlation based image analysis routines. Image shifts between zone axes in the two-correlated diffraction pattern are measured with sub-pixel precision and this realises the ability to measure changes in interplanar angles and lattice orientation with a high degree of sensitivity. These shifts are linked to strains and lattice rotations through simple geometry. In this manuscript, we outline the basis of the technique and two case studies that highlight its potential to tackle real materials science challenges, such as deformation patterning in polycrystalline alloys.