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通过制备Al-10Er-5Sr中间合金并分析其微观组织和相成分,以研究Er和Sr共同作用对A356铝合金微观组织和力学性能的影响.根据微观组织的发展和力学性能的变化,确定了Al-10Er-5 Sr中间合金在A356铝合金中的最佳含量.研究结果表明:Al-10Er-5Sr中间合金主要由α-Al,Al4Sr和Al3Er相组成.A356铝合金中加入质量分数0.6％的Al-10Er-5Sr合金后展示了最优的组织和力学性能,其中合金的二次枝晶臂间距减小到20.2 μm,针状共晶硅向纤维状共晶硅转变.由于微观组织的改善,加入0.6％的Al-10Er-5Sr的A356合金抗拉强度提高到了203.5 MPa,与未添加中间合金相比,性能明显提高.对晶粒细化和变质机理进行了分析和讨论.“,”In order to investigate the combing effect of Er and Sr on the microstructure and mechanical properties of A356 alloy,Al-10Er-SSr master alloy was fabricated and its microstructure and phase compositions were investigated.The optimal content of Al-10Er-5Sr in A356 alloy was obtained according to the evolution of microstructure and mechanical properties.The results show that α-Al,Al4Sr and Al3Er are the main phases in Al-10Er-SSr.In addition,the aluminum alloy with 0.6wt％ Al-10Er-SSr exhibits optimal microstructure and mechanical properties,with the secondary dendrite arm spacing (SDAS) decreasing to 20.2 μm and acicular-like eutectic silicon transforming to fibrous.Due to the improved microstructure,the ultimate tensile strength of the alloy (with 0.6wt％ Al-10Er-SSr) increases to 203.5 MPa,which is much better than that of untreated A356 aluminum alloy.Finally,the grain refinement and modification mechanisms were discussed.