中文摘要：

通过快速凝固和变质处理的综合作用，在铸态铝硅亚共晶合金中原位获得了纤维硅相组织。讨论了各种因素对硅相形态及其演化的影响，重点讨论变质处理对合金组织的改性机制，同时还详细讨论了冷却速率对硅相形态演化的影响。此外，本研究提供了一种制造直纤维增强铝基复合材料的新方法。

英文摘要：

The in-situ fibrous Si phase microstructure was obtained in as-cast Al-Si hypoeutectic alloy under the combined effects of rapid solidification and modification. The evolution of Si-phase morphology under such effects was discussed. Focus was based on the modification mechanism of the alloy. Furthermore, the effect of cooling rate on the morphology evolution of Si was discussed. This paper introduced a new approach of fabricating the straight fiber-reinforced Al-based composite.