Modification of hypereutectic Al-Si alloy by Sr and PM was conducted.The addition sequence

addition and long effectiveness of the compound modifier were investigated.The results show that addition sequence of the compound modifier obviously affects the dimension of Si phase.Adding PM modifier before adding Al-Sr master alloy

the shape of primary silicon is rosset-like in which the fine round-point eutectic silicon appears in the aluminum alloy.On the contrary

the dimension of the primary silicon in A390 alloy is obviously smaller than that of the modified alloy with single PM modifier.The average size of the primary silicon can be reduced to 35μm with modification of 1%PM addition and 0.4% of the alloy weight for Al-10Sr master alloy addition.Moreover

the PM and Sr compound modification has a better long effectiveness.