Microstructural evolution in recrystallized and unrecrystallized Al-Mg-Sc alloys during superplastic deformation

► Microstructural evolution of extruded Al-Mg-Sc was divided into three stages. ► Subgrain rotation and coalescence occurred in early strain hardening stage. ► Dynamic recrystallization in the middle stage resulted in strain softening. ► Grain boundary sliding and dynamic grain growth occurred in final deformation stage. ► Friction stir processed alloy remained a random grain distribution at various strains.