Ultra-fine grained Mg-Zn-Ca-Mn alloy with simultaneously improved strength and ductility processed by equal channel angular pressing

The influence of equal channel angular pressing (ECAP) on the microstructure, texture evolution and mechanical properties of extruded Mg-5.0Zn-0.5Ca-0.3Mn (weight percent) alloy has been systematically investigated in the current study. A typical ultra-fine grained (UFG) structure is obtained in the as-ECAPed alloy for 4 passes, due to a completed recrystallization process. With the increasing ECAP pass, the conventional basal texture can be gradually changed to an asymmetric non-basal texture with its basal plane inclined to normal and transverse directions ∼45°, which is related to the typical shear mode, leading to an obvious increase of Schmid factor for the activation of basal slip system. The room-temperature tensile yield strength, microhardness and ductility of extruded alloy are simultaneously improved by successive ECAP processing, which is derived from the grain refinement and texture modification.