Effect of effective strain gradient on texture and mechanical properties of Mg-3Al-1Zn alloy sheets produced by asymmetric extrusion

In the present study, Mg-3Al-1Zn (A231) alloy sheets were fabricated by conventional extrusion (CE) and asymmetric extrusion (AE) processes. The microstructures, textures and mechanical properties of the AE and CE AZ31 sheets were examined and compared. The results showed that a tilted weak basal texture and microstructure refinement were obtained in the AE AZ31 sheet compared with the CE AZ31 sheet. The reason for the texture weakening and microstructure refinement was ascribed to an introduction of large effective strain gradient throughout the normal direction during the AE process. In addition, the AE AZ31 sheet exhibited lower yield strength and r-value, but larger ductility and n-value. Improving mechanical properties for extruded AZ31 sheet were achieved by the AE process.