The improved mechanical properties of Mg–Zn-Nd alloy with Ca addition via grain refinement and nano precipitates.

Micro-alloying of Ca in Mg–1Zn-0.3Nd (wt.%) alloy is found to significantly improve tensile strength and process high ductility simultaneously. It closely correlates with grain refinement and the increased coherent nano Mg 2 Ca and (Mg, Zn) 3 Nd precipitates. Ca addition enhances alloying elements co-segregation at grain boundary and promotes grain refinement. Furthermore, nano Mg 2 Ca particles induced by Ca addition can significantly promote the precipitation of (Mg, Zn) 3 Nd phase via the heterogeneous nucleation mechanism owing to their excellent coherency relationship and ultimately lead to the pronounced strengthening effect. In addition, both fine grains and the coherent characteristics between Mg 2 Ca, (Mg, Zn) 3 Nd, and Mg matrix facilitate strain coordination during deformation and yield relatively high ductility. • Micro-alloying Ca in Mg–Zn-Nd alloy significantly increases tensile strength while keeping high ductility. • Ca addition enhances the co-segregation of alloying elements at grain boundary and refines grain size. • Nano Mg 2 Ca particles and the induced (Mg, Zn) 3 Nd precipitates with excellent coherency relationship lead to the pronounced strengthening effect. [ABSTRACT FROM AUTHOR]