Effect of equivalent strain and redundant shear strain on microstructure and texture evolution during hot rolling in Mg–3Al–1Zn alloys

Equivalent strain and redundant shear strain distribution in the roll bite during normal rolling were calculated by a numerical integration method combined with the experimental method. The microstructural parameters, such as length of high-angle grain boundaries (HAGB), length of low-angle grain boundaries (LAGB) per unit area, and (0002) basal texture in surface layer and center layer were measured quantitatively by EBSD or X-ray diffraction. The effect of equivalent strain and redundant shear strain on the microstructure and (0002) basal texture evolution in AZ31 alloy during hot rolling were examined. As a result, it was found that the formation of the HAGB depends on the equivalent strain, while the formation of the LAGB is strongly affected by the redundant shear strain, which restrains the formation of the LAGB. The experimental results also suggest that the redundant shear may have little effect on improving DRX and weakening the (0002) basal texture intensity when the redundant shear strain is in small to moderate range (≤0.8).