Orientational analysis of static recrystallization at compression twins in a magnesium alloy AZ31

摘要

In contrast to cubic metals, the dominant recrystallization nucleation site of hexagonal magnesium is compression twins or the shear bands evolved from them. In this paper, we determine the macrotex-tures and microstructures of a magnesium alloy AZ31 during static recrystallization. We interpret these data according to a microtexture analysis performed with the EBSD technique of new grains formed at compression twins in the early stage of static recrystallization. The results show that the orientation characteristics in local regions during nucleation are similar to those of subgrains within compression twins or shear bands. However, the new grains mainly take the orientations of the subgrains, which have been subjected to complicated orientation rotations. This phenomenon is attributed to the large amount of their stored energy. Despite the difference between new grain orientations and those of the deformed matrix, the retained deformation texture after annealing is explained mainly by the incomplete recrystalization of magnesium.