Observation of recovery and recrystallization in high-purity aluminum measured with forward modeling analysis of high-energy diffraction microscopy

High-energy X-ray diffraction microscopy is a non-destructive materials characterization technique that is capable of tracking the evolution of three-dimensional microstructures as they respond to external stimuli. We present measurements of the annealing response of high-purity aluminum using the near-field variant of this technique. The data are analyzed with the forward modeling method which produces orientation maps that exhibit complex intragranular structures. Analysis and verification of results use both reconstructed sample space maps and detector space intensity patterns. Sensitivity to the ordering of the microstructure through both recovery and recrystallization is demonstrated. Sharpening of diffraction peaks and a corresponding reduction in intragranular orientation variations signal recovery processes. The emergence of a new bulk grain (recrystallization) is observed in a disordered region of the microstructure; the new grain has an orientation with no obvious relation to those of grains surrounding the disordered region. (c) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.