Preparation and Effect Analysis of {10–12} Extension Twins at the Edge of AZ31 Magnesium Alloy Plate

The edge samples of AZ31 magnesium alloy plate after hot rolling and annealing were compressed along the rolling direction (RD) under different deformation conditions. Then, the optimal conditions for the generation of {10–12} extension twins and the microtexture evolution of edge samples were studied by using EBSD. The results show that the texture strength of the hot-rolled AZ31 magnesium alloy plate was significantly greater than that of the middle part. When the compressive strain along the RD was small at the edge of the rolled piece at room temperature, a large number of extension twin layers were generated. Grain matrix and twins coexisted. As the strain increased to 8.19%, the grains completely transformed into extension twins. Along with the generation of extension twins, hard-oriented grains were consumed in large quantities and the weakening effect of the basal texture was proportional to the volume fraction of the extension twins, while at high temperature (250 °C), the slip dominated the plastic deformation process.