Evolution of microstructure and mechanical properties of WE43 magnesium alloy during multi-pass hot rolling

The evolution of microstructure and mechanical properties of WE43 magnesium alloy during multi-pass hot rolling was investigated. Results revealed that multi-pass hot rolling promoted the formation of small second phases and this was conducive to the multiple dynamic recrystallization, consequently improving the microstructure homogeneity and refining the average grain size to 8.83 μm from 34.3 μm of the initial material. Meanwhile, the rolling deformation rotated abundant grain c-axes toward the normal direction and one strong fiber texture developed. Owing to the fine-grained strengthening, second phase strengthening, and texture modification, the yield strength along the rolling direction (RD) was improved to 324 MPa in the Pass 3 sheet from 164 MPa in the initial material. In addition, the deformation mechanism distribution maps indicated that the yield strength anisotropy between the RD and the transverse direction (TD) was attributed to the effects of the texture component on the dominant mechanisms. During the tensile test, the dominant deformation mechanism was the prismatic slip affected by RD strong basal texture, while was less proportion of prismatic slip under the influence of TD weak basal texture. Compared to the basal slip, the higher critical resolved shear stress of prismatic slip made the increase in yield strength along the RD higher about 51MPa than that along the TD (RD: 160 MPa, TD: 109 MPa).