采用挤压铸造法制备Ａｌ２Ｏ３／Ａｌ－Ｓｉ合金复合材料。文章研究了增强体对铝硅合金中硅相形貌的影响。结果表明，氧化铝短纤维和硅相之间存在共格界面。此纤维可为硅相的非自发形核提供适宜的结晶衬底。复合材料中的初生硅可在短纤维表面形核并生长为颗粒状。复合材料中的纤维在Ａｌ－Ｓｉ共晶体的共生生长过程中，可触发硅相中的孪晶，导致纤维附近的共晶硅呈变质形态。 Preparation of Al2O3 / Al-Si Alloy Composites by Squeeze Casting. The effect of reinforcement on the phase morphology of silicon in Al-Si alloy was studied. The results show that there is a coherent interface between the alumina short fibers and the silicon phase. This fiber provides a suitable crystalline substrate for the non-spontaneous nucleation of the silicon phase. Primary silicon in composites can nucleate on the surface of staple fibers and grow into granular form. During the symbiotic growth of Al-Si eutectic, the fibers in the composite can trigger twinning in the silicon phase, resulting in the formation of eutectic silicon near the fiber.