EBSD patterns simulation of dislocation structures based on electron diffraction dynamic theory

Abstract

Electron backscatter diffraction (EBSD) technology is a powerful tool for materials characterization including crystal orientation mapping, phase identification, and strain analysis. However, it is still challenging for using EBSD to identify crystallographic defects due to the insufficient understanding of the diffraction patterns of different defect structures. In the present work, EBSD patterns of FCC-Fe with 1/2 < 110 > edge dislocation dipole and 1/6 < 11̅2 > screw dislocation quadrupole structures are simulated by the revised real space (RRS) method. Our results showed that the presence of dislocations deteriorates the overall quality of the diffraction pattern and have different effects on different Kikuchi bands and Kikuchi poles. The edges of the Kikuchi band corresponding to the edge dislocation glide plane are sharp and the diffraction details within the band are clear. The sharpness of the edges of the Kikuchi band corresponding to the crystal plane normal to the dislocation Burgers vector is reduced, but the intra-band diffraction details are clear. Other Kikuchi bands show obvious anisotropic blurring. The diffraction details of the Kikuchi pole corresponding to the screw dislocation Burgers vector are clear, the edges of the Kikuchi bands across this pole are sharp, and the diffraction details within the bands are clear in the segments close to this pole and blurred in the segments far away from it. Other Kikuchi bands and Kikuchi poles are blurred. Our results indicate that the EBSD pattern can be simulated based on the electron diffraction dynamic theory and the correlation between dislocation structure and EBSD pattern is revealed, which provides theoretical guidance for the resolution of dislocation structures by the EBSD technique.

Keywords: Dislocation structure; EBSD pattern; Electron diffraction dynamic theory; Multi-slice method.