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

In the paper, the effects of Gd addition on the as-cast microstructure and mechanical properties of the Mg–3Sn–2Ca magnesium alloy were investigated. The results indicate that after adding 0.42–1.79 wt.%Gd to the Mg–3Sn–2Ca alloy the GdMgSn phase is formed, and the primary CaMgSn phases are changed from coarse needle-like net to relatively fine short block and/or particle-like shapes. Furthermore, an increase in Gd amount from 0.42 wt.% to 1.79 wt.% causes the volume fraction of the CaMgSn and Mg2Ca phases to gradually decrease and increase, respectively. In addition, adding 0.42 wt.%, 0.88 wt.% or 1.79 wt.%Gd to the Mg–3Sn–2Ca alloy can improve the tensile and creep properties of the alloy. Among the Gd-containing Mg–3Sn–2Ca alloys, the alloy added 0.42 wt.%Gd exhibits the best tensile properties while the alloy added 1.79 wt.%Gd has the best creep properties.