Improving mechanical properties of Al–Si–Cu–Mg alloys by microallying Sc using thermodynamic calculations

The mechanical properties of Al–Si–Mg alloys are largely related to eutectic Si, intermetallics and pores. In this study, the effects of the Sc addition on the eutectic Si, Sc containing precipitates and pores were investigated, and the mechanical properties of the alloy were improved by adding Sc. The Sc addition leads to the formation of Al 3 M (M = Sc, Zr, Ti,V) and reduction of pore size, increasing the yield strength (YTS), ultimate tensile strength (UTS) and elongation (EL) of the alloy after the T6 heat treatment. The formation of thermally stable Al 3 M (M = Sc, Zr, Ti,V) after the T6 heat treatment improves the elevated temperature strength.