Damage analysis of hot-rolled AZ31 Mg alloy sheet during uniaxial tensile testing under different loading directions

Uniaxial tensile loading was applied to study the mechanical anisotropy of the hot-rolled AZ31 Mg alloy sheet at room temperature. Tensile direction was varied in the transverse plane and in the angles of 0°, 10°, 20° and 45° from the rolling direction. The tensile tests showed an unexpected result that the 10° sample had the best combination of strength and ductility. To clearly explain the anisotropic behaviors, the damage evolution assisted by crystal plasticity finite element model was successfully employed. The simulated results showed that the prismatic and pyramidal slips induced heavy damage in the 0° sample. Also, the pyramidal slip caused the premature failure in the 20° sample. The high-density basal dislocations led to high ductility and low strength in the 45° sample. A new perspective was thus obtained in which the 10° sample sustained slight damage and had the best combination of strength and ductility.