研究了过共晶铝硅合金在熔体混合处理时高、低温熔体的成分及配比对初生硅相细化的影响, 探讨了熔体混合工艺的长效性和重熔稳定性。结果表明:混合前高、低温熔体的硅含量差异越大, 则混合后合金中初生硅相越细小; Al-30%Si与Al-10%Si合金熔体按质量比1∶1混合可获得最佳的细化效果, 其初生硅尺寸为36.9 μm;混合熔体炉外停放有效期小于5 min, 而在830 ℃的炉内保温100 min以内, 初生硅的尺寸均在36 μm左右;熔体混合处理具有较好的一次重熔稳定性, 但其细化效果随着二次重熔保温时间的延长而逐渐丧失。

Influences of composition and proportion of high and low temperature melt on the primary Si phase refinement of hypereutectic Al-Si alloy during melt mixing treatment were investigated. The long lasting effectiveness and re-melting stability of the melt mixing treatment were also discussed. It is found that the larger the difference of Si content between the high and low temperature melts before mixing, the smaller the grain size of primary Si phase in the mixing alloy. Mixing Al-30%Si melt and Al-10%Si malt in a weight proportion of 1∶1 could obtain the optimal refining effect that the primny Si phase size was 36.9 μm. The validity of the mixing melt was less than 5 min when holding outside the furnace directly, while holding at 830 ℃ inside the furnace, the size of primary Si was about 36 μm within 100 min. Melt mixing treatment had a good first time re-melting stability, but its refinement effect gradually lost with the prologation of second time re-melting.