Effects of cerium on as-cast microstructure and mechanical properties of Mg–3Sn–2Ca magnesium alloy

Abstract

The Mg–3Sn–2Ca– xCe ( x = 0–2.0 wt.%) alloys were prepared by permanent mould casting method, the effects of Ce on the as-cast microstructure and mechanical properties of the alloys were investigated. The results indicated that the volume fraction and size of CaMgSn phase in the Mg–3Sn–2Ca alloy respectively were decreased by adding 0.5–2.0 wt.%Ce, and the average size of CaMgSn phase in the Mg–3Sn–2Ca alloys added 1.5 or 2.0 wt.%Ce was relatively smaller. The main phases in the as-cast Mg–3Sn–2Ca alloys with and without adding Ce were α-Mg, CaMgSn and Mg 2Ca phases, and Mg 12Ce phase were found in the alloys added more than 1.0 wt.%Ce. The addition of Ce improved the tensile and creep properties of Mg–3Sn–2Ca alloy, and the mechanical properties of Mg–3Sn–2Ca alloys added 1.5 or 2.0 wt.%Ce were relatively higher. The strengthening mechanism of Ce-containing Mg–3Sn–2Ca alloys was mainly attributed to the refinement of CaMgSn phase.