Role of [formula omitted] twinning in the anisotropy and asymmetry of AZ31 magnesium alloy under high strain rate deformation

Abstract

In order to investigate the role of {101‾2} extension twinning in anisotropy and asymmetry of highly textured magnesium alloy under high strain rate deformation, tensile and compression deformation were conducted by Split Hopkinson Tension and Pressure Bar under the strain rate of 1800s−1. With the help of theoretical calculated Schmid Factors (SFs), the dynamic tensile and compression behavior and deformation mechanism of extruded AZ31 magnesium alloy along extrusion direction (ED) and transverse direction (TD) were analyzed in the present paper. The results demonstrated that extruded AZ31 magnesium alloy shows obvious anisotropic and asymmetric behaviors under high strain rate deformation and the anisotropic and asymmetric behaviors are arisen from the different role of {101‾2} extension twinning. The Schmid Factor calculation results of six extension twinning variants revealed that the six variants have the same opportunity to activate under tensile loading along TD, while for compression along ED, only two variants have the opportunity of operating due to the highest SF among the six variants. When high strain rate tensile loading was applied along ED and compression loading along TD, {101‾2} extension twinning is not favored.