Effect of differential speed rolling on the anisotropy of mechanical properties and texture evolution of AZ31 Mg alloys

We herein report a significant improvement of the ductility of AZ31 (Al: 3 wt%, Zn: 1 wt%, balance Mg) sheets processed by differential speed rolling (DSR). The DSR sheets under tension in the rolling direction exhibited a plastic strain more than 1.5 times larger than the sheets prepared by conventional rolling (CR), and simultaneous improvements of in-plane isotropy. The origin of these changes has been examined by texture and structural characterizations. The (0 0 0 2) pole intensity of the as-rolled DSR sheet is strongly accumulated in the normal direction, which is preserved after deformation regardless of tensile directions; while that of as-rolled CR sheet show clear splitting, which further broadens after tensile tests. It is suggested that these changes are brought about by the application of a large shear strain to DSR sheets, which resulted in the clear (0 0 0 2) texture, and subsequent ease of the activation of prismatic slip during the deformation.