The second phases of Mg–xAl–ySi–Ca alloys and their influences on properties

The types and changes of the second phases in the Mg–xAl–ySi–0.3Ca alloys and their effects on the properties of the alloys were studied. The results showed that within a certain range of Si and Al content, Si had the greatest influence on the size of the Mg 2 Si phase, while Al content affected the size and morphology of Mg 17 Al 12 and Mg 2 Si phases. The CaMgSi phases were less affected by the Al and Si content. In a tensile test, the as-cast alloy had the best performance when it contained small Mg 17 Al 12 and Mg 2 Si phases, and the Mg 17 Al 12 phase was more likely to become the fracture source. The alloy we tested with the best corrosion resistance was Mg–4Al–0.7Si–0.3Ca alloy, the worst was Mg–6Al–0.7Si–0.3Ca alloy.