The effects of alloying elements on microstructure and properties of gravity casting Mg–Sn–Al–Si alloy

In the present work, the effect of alloying elements on microstructure and properties of Mg–Sn–Al–Si alloy has been investigated. The microstructures of the alloys were mainly consisted of α-Mg, Mg17Al12, Mg2Si and Mg2Sn phases. To improve the corrosion and mechanical properties by modifying the shape of precipitates in the matrix, trace amounts of Sr and Zn were added to these alloys. Analysis of the mechanical properties indicated that Sr and Zn addition improved tensile strength. On the other hand, for the corrosion resistance of the TAS652 alloy, the addition of small amount Sr was beneficial but the Zn addition was detrimental.

► TAS652, TAS652-Sr and TAS652-Zn alloy were fabricated by gravity casting.
► The microstructures of TAS652 alloy were mainly consisted of α-Mg, Mg17Al12, Mg2Si and Mg2Sn phases.
► Sr addition to TAS652 alloy leads to morphology modification of Mg2Si phase and it induces positive effects on mechanical and corrosion properties.