Effects of trace Gd concentration on texture and mechanical properties of hot-rolled Mg–2Zn–xGd sheets

The effects of Gd concentration（0.1, 0.3, 0.7 wt%） on the microstructure, texture and mechanical properties of rolled and annealed Mg–2Zn– x Gd sheets have been investigated aiming to develop low cost and high ductile Mg–Zn–Gd sheets. Dynamic recrystallization, static recrystallization and grain growth during hot rolling process and annealing process were delayed with increase of Gd concentration, leading to fine grain microstructure. The rolled 0.1 wt% Gd sheet showed strong basal texture which remained stable after annealing process and exhibited medium elongation of about 25%. In contrast, the rolled 0.3 wt% Gd sheet had weak basal texture which transformed to non-basal texture with double peaks tilted about ±48° to the transverse direction due to the static recrystallization during annealing process. Consequently, the annealed sheets exhibited higher elongation of 40% along the rolling direction and 50% along the transverse direction due to the existence of non-basal texture. It is suggested that the minimum effective concentration for texture randomization in the Mg–2Zn– x Gd alloy is about 0.3 wt%.