Effect of unidirectional rolling and cross-rolling on microstructure and mechanical anisotropy of Mg-Gd-Y-Ag-Zr plates

Abstract

Mg-10Gd-2Y-0.4Ag-0.4Zr (wt%) alloy plates are prepared by Unidirectional Rolling (UR) and Cross-Rolling (CR). The effects of these two methods on the microstructure and mechanical anisotropy of the plates are investigated in detail by combining microstructure characterization and room temperature tensile tests. The results show that the UR plate has a finer grain size and obvious dynamic precipitation response, with many dynamically precipitated β phase particles distributed along the rolling direction and forming particle strips. The CR plate has experienced more dynamic recovery, and the driving force of dynamic recrystallization is decreased, resulting in larger grain size. However, the more dynamic recovery reduces the dynamic precipitation response and leads to a more uniform microstructure, and hardly finds dynamic precipitated β phase particles in the CR plate. The texture component of the UR plate is the basal texture and TD-split texture, while that of the CR plate is the basal texture and rare RT-split texture. The TD-split texture and the anisotropic distributed particle strips in the UR plate caused a strong mechanical anisotropy. While the yield anisotropy and elongation anisotropy of the CR plate are reduced simultaneously due to the more uniform microstructure and rare RT-split texture.