Recrystallization mechanisms of low stacking fault energy metals as characterized on model silver single crystals
Résumé
The microstructural evolution during light annealing of a representative low stacking fault energy metal has been characterized by detailed electron microscopy orientation measurements. High-purity silver single crystals with initial C(112)[111]orientation were channel-die deformed to reductions of 32% and 67%; the crystals first developed twin–matrix layers and then compact clusters of shear bands. The latter are the nucleation sites for recrystallization. Microtexture analysis of partially recrystallized samples indicates a simple 25–40°relation between isolated nuclei and one of the two as-deformed groups of components (twins or matrix). This implies the existence of a second misorientation with respect to the other component, usually described as 50–55°. During the rapid growth stage, recrystallization twinning radically increases. This twinning is considered to operate after the formation of the primary nuclei and, in C-oriented crystals, also plays a critical role in the formation of the cube orientation.