Estimation of the Plastic Anisotropy of Textured Magnesium Alloy AZ31 Sheets Using a Thermoactivation Model

The dependence of normal anisotropy coefficient R on angle α in the sheet plane (angle α = 0° corresponds to the rolling direction) is determined in terms of a thermoactivation model of plastic deformation using the texture coefficients determined for magnesium alloy AZ31 sheets. The texture coefficients are the coefficients of the expansion of an orientation distribution function into a series in generalized spherical functions. The calculated values of R (α) are compared with the experimental values obtained during tensile tests at a temperature of 180°C. Good agreement between the calculated and experimental results is observed provided that tension at elevated temperatures is ensured by the action of the basal, prismatic, and ⟨c̅ + a̅⟩ pyramidal slip at the ratio of the critical resolving shear stresses of 1 : 2.3 : 2.8, respectively.