Fabrication of ZK60 magnesium alloy thin sheets with improved ductility by cold rolling and annealing treatment

Thin ZK60 magnesium alloy sheets with ultrafine-grain structure were successfully fabricated by continuous cold rolling with proper intermediate annealing treatments at 503–523 K for 30 min. Meanwhile, microstructure uniformity and planar texture anisotropy were strikingly improved by rolling deformation and static recrystallization, resulting in continuous improvement in the strength anisotropy. Excellent ductility more than 30% in fracture elongation was achieved after further annealing treatment at a lower temperature of 473 K. This was primarily attributed to the significant weakening of the {0 0 0 2} pole intensity and grain refinement during the process. It is shown that mechanical properties of the final sheets could be closely controlled by the present process.

► Thin ZK60 Mg alloy sheets were fabricated by cold rolling and annealing treatment. ► Excellent ductility with strength isotropy was obtained during annealing. ► Fine and homogeneous microstructure was obtained after annealing. ► Grain refinement and basal texture weakening significantly enhanced ductility.