采用熔体混合及等温处理制备半固态过共晶铝硅合金,研究了等温处理参数对Al-20%Si合金中初生硅形态的影响。结果表明,熔体混合可显著细化初生硅组织,在610℃下保温15 min等温循环加热3次后Al-20%Si合金中初生硅球化效果显著,形状因子最高。 The semi-solid hypereutectic Al-Si alloy was prepared by melt mixing and isothermal treatment. The effect of isothermal treatment parameters on the morphology of primary Si in Al-20% Si alloy was studied. The results show that the primary silicon microstructure of Al-20% Si alloy is remarkable and the shape factor is the highest when Al-20% Si alloy is heated by isothermal cycle heating at 610 ℃ for 15 min.