Accuracy and precision of near-field high-energy diffraction microscopy forward-model-based microstructure reconstructions

Abstract

The accuracy of the near-field high-energy diffraction microscopy (nf-HEDM) technique is evaluated by directly comparing an nf-HEDM reconstructed microstructure with an electron backscatter diffraction (EBSD) characterization of the same microstructure. A high-purity gold oligocrystal was chosen for characterization in order to facilitate direct one-to-one comparison between the reconstructions given by each technique. By using the comparatively high spatial resolution of the EBSD reconstruction as the ground truth for the grain-boundary network's morphology, it is determined that nf-HEDM locates internal grain boundaries with an accuracy on average better than the resolution of the imaging detector used or within the reconstruction voxel size, whichever is larger. By taking the intragranular misorientation in well ordered grains as a proxy for orientation resolution, it is determined that standard data collection procedures determine crystallographic orientations to better than 0.1°. The effects of various modified data collection procedures are also examined.