Influence of Ca Content on Microstructure and Mechanical Properties of Extruded Mg–Al–Ca–Mn Alloys

Herein, the effects of Ca content on microstructure, texture and mechanical properties of extruded Mg–3Al–0.4Mn–xCa (x = 0.4, 0.8 and 1.2  wt%) rods are systematically investigated. The results reveal that the alloy, with Ca content of 0.8 wt%, exhibits the highest strength and ductility, possessing an ultimate tensile strength of 267.57 MPa and elongation (EL) of 16%. This is mainly due to the gradual transformation of typical fiber texture into a texture with a [10-11] component parallel to the extrusion direction (ED), which increases the Schmid factor of pyramidal slip and enhances the activation rate of pyramidal ⟨c + a⟩ slip. Simultaneously, the as-formed spherical phases and segregation of Ca at grain boundaries render a significant influence on the strength and ductility of the alloy.