Shear bands in magnesium alloy AZ31

During deformation of magnesium at low temperatures, cracks always develop at shear bands. The origin of the shear bands is the {10 (1) over bar1} twinning in basal-oriented grains and the mobility of this type of twin boundary is rather low. The most frequent deformation mechanisms in magnesium at low temperature are basal slip and {10 (1) over bar2} twinning all leading to the basal texture and therefore the formation of shear bands with subsequent fracture. The investigation on the influences of initial textures and grain sizes reveals that a strong prismatic initial texture of <0001> parallels to TD and fine grains of less than 5 mum can restrict the formation and expansion of shear bands effectively and therefore improve the mechanical properties and formability of magnesium.