Local orientation gradient and recrystallization of deformed copper

The texture and grain boundary structure of recrystallized materials is dependent upon the character of the deformed matrix, and the selective nucleation and growth of crystallites from the deformation structure. Proper description of the deformed matrix includes not only local crystallite lattice orientation, but also dislocation content and gradients in structural features that contribute to the heterogeneity of the nucleation and growth processes. In-situ recrystallization experiments were performed on pure copper deformed by equal channel angular extrusion, and characterization of the structure on the surface of bulk specimens was accomplished using the EBSD technique. The character of the structure where nucleation preferentially occurs is presumed to be in heavily deformed regions as nuclei were first observed in such microstructures. Grain growth is observed to be heavily dependent upon twinning processes.