The Al-Si-Cu alloy was prepared by permanent mold casting.The microstructure of the alloy was analyzed by SEM and EDS

and the mechanical properties of the alloy prepared were measured under different heat treatment conditions.The properties of the Al-Si-Cu alloy were analyzed by comparing microstructure

and the optimized heat treatment process of Al-Si-Cu alloy was determined by thermal analysis.The results show that Al-Si-Cu cast alloy exhibits good castability and excellent mechanical properties after heat-treatment.With Cu content in range of 0.6%

3.5%

with the increase of Cu content

Al

2

Cu and Q-Al

5

Cu

2

Mg

8

Si

6

phase will be increased

so the alloy exhibits the higher strength and the lower elongation

where the maximal increment of tensile strength reaches up to 17%.