On the deformation, recrystallization and texture of hot-rolled Mg–2.9Y and Mg–2.9Zn solid solution alloys—A comparative study

Abstract

Abstract The microstructure and texture evolution during hot rolling (350 °C) and subsequent annealing are compared in Mg–2.9Y and Mg–2.9Zn (in wt%) solid solution alloys. It is shown that Y in solid solution, unlike Zn, suppresses dynamic recrystallization. Nevertheless, the two alloys exhibit similar, strong basal textures. Upon isothermal annealing of the rolled material at 400 °C, the texture is weakened only in the Mg–2.9Y alloy. The texture weakening is attributed to static recrystallization in basal parent grains. During rolling of Mg–2.9Y, basal parent grains store a high amount of basal dislocations that are organized in a very fine substructure. Such a highly energetic configuration gives rise to fine recrystallized grains with a wide orientation spread during annealing. On the other hand, off-basal parent grains with c-axes close to the RD–TD plane develop coarser substructure accommodating prismatic slip during rolling. The energy stored in these grains is significantly lower than that in basal ones (∼20 times smaller). Static recrystallization at off-basal parent grains leads to coarse new grains and involves rotations about c-axis. The texture weakening induced by static recrystallization in Mg–2.9Y was found to result in higher ductility and lower anisotropy when compared to Mg–2.9Zn.