在铝硅合金熔体中加入Ｔｉ和Ｂ成理想配比的反应剂，原位生成颗粒增强铸造复合材料ＴｉＢ２／ＡｌＳｉ。对该复合材料的显微观测表明：原位生成的ＴｉＢ２颗粒均匀弥散分布在αＡｌ基体中，其平均尺寸＜１μｍ，呈接近等轴的多面体，能保证在凝固过程中不沉淀，但在αＡｌ与共晶硅交界处存在ＴｉＢ２颗粒的微观偏聚现象；初生αＡｌ晶粒细化，形状由树枝状转变为等轴状或菊花状；复合材料的弹性模量比基体铝硅合金的高 In the Al-Si alloy melt Ti and B into the ideal ratio of reactants, in-situ particle reinforced cast composite TiB2 / Al Si. The microscopic observation of the composite shows that the in-situ TiB2 particles are uniformly dispersed in the α-Al matrix and have an average size of less than 1μm, and are close to the equiaxed polyhedron, which ensures no precipitation during solidification. However, αAl and eutectic silicon at the junction of TiB2 particles microscopic segregation phenomena; primary αAl grain refinement, the shape from the dendritic to equiaxed or chrysanthemum-like; composite material modulus of elasticity than the matrix Al-Si alloy height of