Microstructural characterization of high pressure die cast Mg-Zn-Al-RE alloys

► The microstructure of high pressure die cast AE44 alloy was modified by Zn addition. ► Zn addition initially reduces and then increases the amount of externally solidified grains. ► The equiaxed grains were changed into dendritic microstructure with increasing Zn content. ► The Al-RE phases were gradually replaced by Al2REZn2 phase with increasing Zn content.