The effects of the squeeze casting process on the microstructure, mechanical properties and wear characteristics of hypereutectic Al–Si–Cu–Mg alloys have been investigated by optical, scanning and transmission electron microscopy and mechanical property test; the wear behaviour was investigated using a pin-on-disc configuration; alloy ingots were prepared by gravity casting, liquid squeeze casting and semisolid squeeze casting. The results show that the Si phase was refined and the α-Al dendrites transformed to rosette grains after semisolid squeeze casting. The peak intensity of the second phase decreased after extrusion, indicating that extrusion promotes the dissolution of solute elements into the matrix. Among the three casting processes, the alloys formed by semisolid squeeze casting had the best mechanical properties. Tensile strength, elongation and Brinell hardness reached 187.67 MPa, 2.33% and 142.5 HB, respectively. After semisolid squeeze casting, the morphology of the wear surface was flat and the number of spalling pits and furrows is less. Meanwhile, the friction coefficient and wear loss of the alloy sample are minima. Due to the uniform distribution of Si phases and equiaxed crystallization of α-Al phase in semisolid squeeze casting Al–Si–Cu–Mg alloys, the wear resistance is markedly enhanced.

通过光学，扫描和透射电子显微镜以及力学性能测试，研究了挤压铸造工艺对过共晶Al-Si-Cu-Mg合金的组织，力学性能和磨损特性的影响。使用销盘结构研究了磨损行为；通过重力铸造，液体挤压铸造和半固态挤压铸造来制备合金锭。结果表明，经过半固态挤压铸造后，Si相得到了细化，α-Al枝晶转变为玫瑰状晶粒。挤出后，第二相的峰强度降低，表明挤出促进了溶质元素溶解到基质中。在这三种铸造工艺中，通过半固态挤压铸造形成的合金具有最佳的机械性能。抗拉强度，伸长率和布氏硬度分别达到187.67 MPa，2.33％和142.5 HB。半固态挤压铸造后，磨损表面的形态是平坦的，剥落坑和沟的数量较少。同时，合金样品的摩擦系数和磨损损失最小。由于半固态挤压铸造Al-Si-Cu-Mg合金中Si相的均匀分布和α-Al相的等轴结晶，耐磨性得到了显着提高。