Texture and microstructure evolution during the symmetric and asymmetric rolling of AZ31B magnesium alloys

Differential speed warm-rolling (DSR) of AZ31B magnesium alloys was carried out, and the microstructure and tensile properties were systematically investigated at various working temperatures and reduction in area. Conventional rolling followed by DSR as a finishing pass revealed low basal intensity and effectively enhanced the mechanical properties. Asymmetric rolling resulted in lower basal intensity compared to symmetric rolling. The intensity of the basal texture decreased with an increase in the rolling temperature. During warm-rolling, fine and equiaxed grains created by dynamic recrystallization were observed. A shear band which formed during warm-rolling contained many twins and displayed an off-basal texture, with the overall grain size in this region smaller than that of other regions. The off-basal texturing and a fine grain size contributed to enhanced elongation. The double twinning strongly hindered the elongation of the AZ31B sheets.