Shear bands in magnesium alloy AZ31
(1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. The 56th Institute of Chongqing, Chongqing 400039, China)
2. The 56th Institute of Chongqing, Chongqing 400039, China)
Abstract: During deformation of magnesium at low temperatures, cracks always develop at shear bands. The origin of the shear bands is the {101-1} 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 {101-2} 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 μm can restrict the formation and expansion of shear bands effectively and therefore improve the mechanical properties and formability of magnesium.
Key words: magnesium alloy; deformation; texture; microstructure