Microstructure, mechanical properties and deformation mechanisms of an as-cast Mg-Zn-Y-Nd-Zr alloy for stent applications

A new Mg-2Zn-0.2Y-0.5Nd-0.4Zr (wt%) alloy designed specially for stent applications has been developed. The as-cast alloy is featured with equiaxed grains with a mean size of about 40 mu m and a small amount of second phase (T phase) distributed discontinuously either at the grain boundaries or inside the grains. This alloy exhibits a tensile elongation of up to 35%, which is much larger than that of most reported other as-cast Mg alloys. The tensile deformation mechanisms have also been investigated. The results show that, besides basal slip, {10 - 12} extension twining and non-basal pyramidal slips can also be observed at initial stage and later stage during tensile deformation, respectively, which are responsible for the good room-temperature ductility. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.