过共晶铝硅合金变质工艺研究

本文研究了P、RE、S单独加入及P-RE、P-S、P-Na联合加入对Al-20％Si合金的变质作用，比较了各自的变质效果。考察了联合变质的最佳变质温度及联合变质长效性。结果表明，P-RE、P-S联合变质具有较好的双重变质效果，联合变质后合金机械性能有较大的提高。最佳变质温度为840℃左右，变质效果至少可持续3h.

Study on the Modification Technique for the Hypereutectic Al-Si Alloys

In this paper,the role of P. RE. S or both of P and RE. S, Na in the modification of Al-20%Si alloy has been studied. The results of modification are evaluated synthetically.The best modifying temperature and the effective period of the comodification have been investigated.the results show that the combination of P and RE or P and S has an excellent co-mmodifying effect.The mechanical properties have been sincreased largely.The best modifying tmperature is about 840℃,and the effective period can last longer than 3 hours.