A framework for generating synthetic diffraction images from deforming polycrystals using crystal-based finite element formulations

A framework for generating synthetic diffraction images on X-ray detectors from individual grains within polycrystals under in situ loading is described. Crystal plasticity-based finite element simulations of three-dimensional (3D) polycrystalline aggregates undergoing deformation were utilized to mimic a far-field High Energy Diffraction Microscopy (HEDM) experiment. The smearing of the diffraction spots on a two-dimensional (2D) area detector was consistent between the experiment and simulation for a target grain within a polycrystalline sample of a Cu-Cr-Zr alloy. The influence of crystallographic neighborhood and grain shape on the diffracted intensity distributions of the diffraction spots, the stress distribution and the misorientation distribution within a grain is also investigated. Key features of the diffraction spots are examined, differentiating between changes with applied stress and changes due to lattice misorientation associated with plastic straining.