Deformation Behavior and Texture Formation in AZ80 Magnesium Alloy during Uniaxial Compression Deformation at High Temperatures

Abstract

High temperature uniaxial compression deformation is conducted on AZ80 magnesium alloy at 673 and 723 K by varying the strain rates ranging from 1.0 × 10⁻⁴ to 5.0 × 10⁻² s⁻¹ in order to investigate the behaviors of deformation and texture formation. Particular attention is paid to the development of basal texture. Under the deformation conditions of this study, work softening is observed in all the stress–strain curves without exception. The results of the microstructure observation reveal occurrence of dynamic recrystallization. Formation of fiber texture during the deformation is confirmed. The main component is (0001) when the peak stresses appearing in the stress–strain curves are more than 15–20 MPa, and it develops together with an increase in the peak stress. In contrast, weak fiber textures having a main component at a position 29° away from the basal plane are formed with deformation conditions giving peak stresses of less than 15 MPa. The stress exponent changes at a peak stress near 20 MPa, suggesting that change in the texture corresponds to the change in the deformation mechanism. It is concluded that the formation of basal texture is due to the continuous dynamic recrystallization resulting from the growth of the subgrains formed by the deformation.