Abstract
An aluminum bicrystal specimen with a twin boundary was deformed in tension to 20%. During the deformation, the specimen developed two different areas inhomogeneously deformed, which were the area with delta-shape along the boundary and the special band of secondary slip (SBSS) inside the component crystals. The misorientation angle between the component crystals changed from 49.0 degrees to 57.3 degrees along the boundary due to the piled-up dislocations.
Two recrystallization mechanisms were recognized at two kinds of inhomogeneously deformed areas in annealing. The strain induced boundary migration (SIBM) nucleated at the inhomogeneously deformed area with delta-shape adjoining to the boundary. The SIBM resulted in the exchange of the component crystal orientations, because the high angle SIBM boundary invading the component crystal had much higher mobility than the original boundary with almost zero misorientation. Recrystallized grains with island-shape were observed at the SBSS. The crystal orientations did not correspond with those before and after the deformation. The present mechanism which generated the recrystallized orientations not in the deformation structure was considered to be an important recrystallization mechanism at low strain.
