Enhancing polycrystalline-microstructure reconstruction from X-ray diffraction microscopy with phase-field post-processing

A novel protocol utilizing a phase-field model was used to process the reconstruction of a polycrystalline microstructure from synchrotron-based high-energy X-ray diffraction microscopy. This approach is an intuitive and standardized alternative to typical image processing routines. It preserves high-confidence regions by deploying a completeness-based mobility parameter in the phase-field model. Phase-field governing equations result in a space-filling grain map that adheres to the physics of the microstructure, i.e., it penalizes high-energy grain shapes and configurations and promotes grain boundary (GB) smoothing. We quantify GB smoothing by measuring, in 2D, the circularity of interior grains and the tortuosity of individual GBs. Results are also presented in 3D. This post-processing protocol can be applied to any X-ray diffraction microscopy reconstruction that consists of a spatial map of grains and corresponding confidence values. Furthermore, it can be adapted to accommodate other types of microstructures, including those that are polyphase.