Coupled grain-boundary migration and sliding were observed in situ in Al bicrystals, with <112>- and <100>- symmetrical tilt grain boundaries, by using X-ray diffraction. The motion of the grain boundaries was induced by a shear stress that permitted the grain boundaries to move parallel, as well as perpendicular, to the applied stress. The activation parameters for the coupled motion were determined and were compared with experimental results on the pure migration process under the influence of a mechanical stress. The measured ratios of the displacements of migration and sliding were also compared with the results of simulations of coupled grain-boundary motion.

In situ Observations of Coupled Grain Boundary Motion. M.Winning: Philosophical Magazine, 2007, 87[32], 5017-31