Comparison of the dislocation density obtained by HR-EBSD and X-ray profile analysis

TL;DR

This paper compares dislocation density measurements obtained by high-resolution EBSD and X-ray profile analysis, demonstrating that EBSD can reliably determine dislocation density through stress distribution analysis.

Contribution

It establishes a direct link between EBSD-derived stress distributions and dislocation density, enabling mesoscale characterization of heterogeneous materials.

Findings

EBSD stress distributions follow an inverse cubic tail consistent with dislocation theory.

Dislocation density can be quantitatively extracted from EBSD data.

Comparison confirms EBSD as a viable method for mesoscale dislocation analysis.

Abstract

Based on the cross correlation analysis of the Kikuchi diffraction patterns high-resolution EBSD is a well established method to determine the internal stress in deformed crystalline materials. In many cases, however, the stress values obtained at the different scanning points have a large (in the order of GPa) scatter. As it was first demonstrated by Wilkinson and co-workers this is due to the long tail of the probability distribution of the internal stress ($P(\sigma)$) generated by the dislocations present in the system. According to the theoretical investigations of Groma and co-workers the tail of $P(\sigma)$ is inverse cubic with prefactor proportional to the total dislocation density $<\rho>$. In this paper we present a direct comparison of the X-ray line broadening and $P(\sigma)$ obtained by EBSD on deformed Cu single crystals. It is shown that $<\rho>$ can be determined from $P(\sigma)$. This opens new perspectives for the application of EBSD in determining mesoscale parameters in a heterogeneous sample.