Grain refinement and texture evolution in AZ31 Mg alloys sheet processed by differential speed rolling

摘要

In AZ31 (Mg-3AI-1wt% Zn) magnesium alloy sheets rolled by differential speed rolling (DSR) at 423 K, many twins appeared at a low reduction rate of 25%, and fine grains (～1 μm) having approximately the same size dominate at a high reduction rate of 55%. In addition to these microstructural changes, the rolled sheets showed a strong texture characterized by (0002) pole tilting about 7 degree from the normal direction (ND) towards the rolling direction (RD) throughout the whole thickness of the DSR sheets. The (1011) pole figure as well as TEM images of the specimen prepared at a reduction rate of 55% indicated that the activation of a prismatic slip played an important role in bringing about dynamical re-crystallization.