Texture and weak grain size dependence in friction stir processed Mg–Al–Zn alloy

The Mg–Zn–Al alloy processed by hot extrusion typically exhibits strong grain size dependence of yield stress. However, the same friction stir processed Mg–Zn–Al alloy samples exhibited much weaker grain size dependence. The high Schmid factor of around 0.3 of the friction stir processed samples is responsible for the low parameters in the Hall–Petch relationship.