Enhancement of mechanical properties and corrosion resistance of Mg–Ca alloys through microstructural refinement by indirect extrusion

Abstract

The effect of indirect extrusion on microstructural refinement, mechanical properties and corrodibility of the pure Mg and Mg–Ca alloys (up to 3wt.% Ca) in Hank’s solution has been systematically studied. After extrusion, mechanical properties including tensile strength and ductility, and corrosion resistance of the Mg–Ca alloys were greatly enhanced in the Mg–Ca alloys with Ca⩾1%. Effective break-up of (semi-)continuous secondary phase (Mg2Ca) existing along grain boundaries or interdendritic regions during extrusion played a critical role in enhancement of the corrosion resistance of the Mg–Ca alloys with Ca⩾1% compared to the as-cast counterparts.