以Yb2O3-Al2O3作为烧结助剂,采用烧结-热等静压工艺制备了具有高致密度和优异力学性能的Si3N4-SiCw复合材料,研究了TiO2含量对Si3N4-SiCw复合材料致密化和力学性能的影响.结果表明:TiO2的加入促进了Si3N4-SiCw复合材料的致密化.随着TiO2含量的增加,Si3N4-8％SiCw复合材料的抗弯强度、断裂韧性和Vickers硬度均呈现出先提高后降低的变化趋势.当TiO2含量(质量分数)为3％时,Si3N4-8％SiCw复合材料的相对密度和综合力学性能最佳,其相对密度、抗弯强度、断裂韧性和Vickers硬度分别为(99.5±0.1)％、(1301±87)MPa、(7.8±0.1)MPa·m1/2、(16.2±0.1)GPa.TiO2和Si3N4之间的原位反应生成的SiO2和TiN对Si3N4-SiCw复合材料的界面结合强度及力学性能产生了重要影响.“,”Si3N4-SiCw composites were prepared via a sinter-hot isostatic pressing (sinter-HIP) process with Yb2O3-Al2O3 as sintering additives. The effect of titania (TiO2) addition on the densification and mechanical properties of Si3N4-SiCw composites was investigated. The results show that the addition of titania enhances the densification of Si3N4-SiCw composites. The flexural strength, fracture toughness and Vickers hardness of Si3N4-8％SiCw composites firstly increase and then decrease with increasing titania content. Si3N4-8％SiCw composites containing 3％ TiO2 have a near-theoretical density and optimal mechanical properties (i.e., the relative density of (99.5±0.1)％, the flexural strength of (1301±87) MPa, the fracture toughness of (7.8±0.1) MPa·m1/2, and the Vickers hardness of (16.2±0.1) GPa). The formation of SiO2 and TiN based on the in-situ reaction between TiO2 with Si3N4 contributes to the improvement of the interfacial strength of bonding between SiC whisker and Si3N4 matrix as well as the mechanical behaviors of the composites.