采用真空热压原位合成法制备Al3Ti增强Mg-Al基复合材料。研究了烧结工艺对复合材料显微结构的影响。探讨了Al3Ti的原位合成机制,提出了Ti和Al的微观反应模型。采用XRD、SEM等方法分析了复合材料的相组成及微观结构。结果表明,Mg-Al基复合材料组织致密,原位合成增强相Al3Ti颗粒在基体中均匀分布,尺寸为0.5～2.0μm,与基体界面紧密结合,同时存在少量残余的Ti和中间相Al-Ti。 Preparation of Al3Ti reinforced Mg-Al matrix composites by in-situ vacuum hot-pressing. The effect of sintering process on the microstructure of the composites was studied. In-situ synthesis mechanism of Al3Ti was discussed, and the microscopic reaction model of Ti and Al was proposed. The phase composition and microstructure of the composites were analyzed by XRD, SEM and other methods. The results show that the microstructures of Mg-Al matrix composites are dense and the in-situ synthesized Al3Ti particles are uniformly distributed in the matrix with a size of 0.5-2.0 μm and are intimately bonded to the interface of the matrix with a small amount of residual Ti and Al-Ti .