Individual effect of recrystallisation nucleation sites on texture weakening in a magnesium alloy: Part 2- shear bands

The entire recrystallisation process of a cold-rolled WE43 Mg alloy containing a high density of shear bands was tracked using a quasi-in-situ electron backscatter diffraction method. The results showed the resultant recrystallised texture arose principally from recrystallisation within shear bands rather than from deformation twins, which made a negligible contribution to the final texture. Only a weakened basal texture with scattered weak texture components was observed after annealing at 450 °C and 490 °C. This is in contrast to the widely reported “Rare Earth” textures, believed to come from shear band recrystallisation. The texture appeared during the nucleation of recrystallised grains and was preserved during subsequent grain growth. Simultaneous occurrence of precipitation on grain and twin boundaries during recrystallisation suppressed any potential preferential grain growth. When annealed at 545 °C, at which temperature both solute drag and Zener pinning were eliminated, a non-basal texture was produced after annealing due to orientated grain growth governed by different grain boundary mobility between basal and off-basal grains.