Effects of minor additions of Ce and Y on as cast microstructure of Mg–3Sn–2Ca magnesium alloy

The effects of minor additions of Ce and Y on the as cast microstructure of Mg–3Sn–2Ca (wt-) magnesium alloy are investigated and compared. Results indicate that adding minor Ce or Y to Mg–3Sn–2Ca alloy does not cause formation of any new phases in the alloy. The as cast Mg–3Sn–2Ca alloy with addition of 0·5 wt-Ce or Y is still composed of α-Mg, CaMgSn and Mg₂Ca phases. However, after adding 0·5 wt-Ce or Y to Mg–3Sn–2Ca alloy, not only the formation of CaMgSn phase in the alloy is suppressed but also the CaMgSn phases in the alloy are effectively refined. In addition, adding 0·5 wt-Ce to Mg–3Sn–2Ca alloy exhibits higher refinement efficiency to the CaMgSn phase in the alloy than adding 0·5 wt-Y. Further investigations need to be considered in order to understand the difference of minor Ce and Y with regard to the refinement of CaMgSn phase in the Mg–3Sn–2Ca alloy.