Asymmetric and symmetric rolling of magnesium: Evolution of microstructure, texture and mechanical properties

Abstract

► Room temperature asymmetrically rolled sample has the grain size 2.3 μm. ► Basal texture forms along the normal direction after symmetric rolling. ► For asymmetric rolling, basal texture is ∼5–10° shifted from the ND. ► A small shear component, if introduced during rolling, increases the ductility. In the present study, asymmetric rolling was carried out for incorporating a shear component during the rolling at different temperatures, and was compared with conventional (symmetric) rolling. The microstructures were investigated using electron back-scatter diffraction (EBSD). The strain incorporated was compared with the help of grain orientation spread (GOS). GOS was eventually used as a criterion to partition the microstructure for separating the deformed and the dynamically recrystallized (DRX) grains. The texture of the partitioned DRX grains was shifted by ∼30° along the c -axis from the deformed grains. The mechanism of dynamic recrystallization (DRX) has been identified as continuous dynamic recovery and recrystallization (CDRR). The partitioned deformed grains for the higher temperature rolled specimens exhibited a texture similar to the room temperature rolled specimen. The asymmetric rolling introduces a shear component which shifts the texture fibre by ∼5–10° from the conventional rolling texture. This led to an increase in ductility with little compromise on strength.