采用螺旋测试装置及球形试样装置,研究了不同的Bi添加量对Al-18%Si、Al-22%Si、Al-26%Si合金铸造流动性及体收缩性的影响。结果表明:2%~3%Bi的加入量(质量分数)对18%Si和22%Si的过共晶铝硅合金能起到良好变质作用,有效改善合金流动性,继续增加硅的含量会降低铸造流动性,对铸造性能影响较大。添加2%Bi对Al-18%Si合金体收缩性改善最佳,达到0.46%;添加1%Bi对Al-22%Si、Al-26%Si合金体收缩性改善最明显。 The effects of different Bi additions on the casting fluidity and bulk shrinkage of Al-18% Si, Al-22% Si and Al-26% Si alloys were investigated by using a helical test device and a spherical sample device. The results show that the addition of 2% ~ 3% Bi can improve the fluidity of the alloy and increase the content of silicon in the hypereutectic Al-Si alloy with 18% Si and 22% Si Reduce the casting fluidity, a greater impact on the casting performance. The best shrinkage of Al-18% Si alloy with addition of 2% Bi was 0.46%. The most significant improvement of shrinkage of Al-22% Si and Al-26% Si alloys with addition of 1% Bi was observed.