In this study, hypoeutectic and eutectic Al–Si alloys were processed through rolling and friction stir processing (FSP), and the effects of deformation routes on the microstructures and mechanical properties of Al–Si alloys were studied. FSP led to the fragmentation and uniform distribution of Si phases in the Al matrix and then eliminated the preferential crack propagation channels of Al–Si alloys during tensile tests. The optimized crack propagation path and high work hardening rate led to a tensile elongation of as high as 39% in FSP Al–7Si alloys. Further rolling refined the Al grains and introduced dislocations into the Al–Si alloys. The fine Si phases, tens of nanometers is size, in the FSP samples promoted grain refinement after rolling. Compared with the Al–Si alloys subjected to warm rolling only, the alloys subjected to FSP and warm rolling exhibited higher strength and ductility. FSP alloys with the highest strength were achieved through cold rolling because of high grain boundaries and dislocation-strengthening effects. This work provided a method for fabricating Al–Si alloys with excellent mechanical properties by combining FSP and rolling.

在这项研究中，通过轧制和搅拌摩擦加工（FSP）加工了亚共晶和低共熔的Al-Si合金，并研究了变形路径对Al-Si合金的显微组织和力学性能的影响。FSP导致Al基体中Si相的破碎和均匀分布，然后在拉伸试验中消除了Al-Si合金的优先裂纹扩展通道。优化的裂纹扩展路径和较高的加工硬化率导致FSP Al-7Si合金的拉伸伸长率高达39％。进一步的轧制细化了Al晶粒，并向Al-Si合金中引入了位错。FSP样品中的细硅相尺寸为几十纳米，促进了轧制后的晶粒细化。与仅进行热轧的Al-Si合金相比，经过FSP和热轧的合金具有更高的强度和延展性。由于高的晶界和位错强化效应，通过冷轧获得了强度最高的FSP合金。这项工作提供了一种通过结合FSP和轧制来制造具有优异机械性能的Al-Si合金的方法。