Influence of annealing treatment on microstructure and properties of AZ31 magnesium alloy sheet processed by equal channel angular rolling

Microstructure and properties of AZ31 magnesium alloy sheet processed by equal channel angular rolling(EACE) and then annealing treated were investigated.The results show that the initial non-basal plane orientation is not changed obviously after annealing treatment at the experimental conditions.With increasing of annealing time and temperature,the homogeneous and equiaxed grains begin to form and grow up and twins disappears gradually.At the same time,the strength decreases with improving the ductility and the anisotropy is weakened.These show that the existence of twins and coarsened grains can reduce the ductility and non-basal plane orientation and refined grains are in favor of the ductility.The clearly yield phenomenon,lower yield strength and larger strain hardening is due to weakening of the(0002) basal plane grain orientation.