用扫描电镜、透射电镜和 X 射线衍射研究了 Si_3N_4-TiC-Co 系复合材料的相组成、显微结构和力学性能。发现 TiC 以 TiC 和 TiN 形式存在,Co 以 CoSi 形式存在。加入 TiC 和 Co 后,复合材料的力学性能得到明显改善,断裂韧性达到7.2MPa·m~(1/m),并且用 Y_2O_3作为助烧剂时,Si_3N_4晶粒成纤维状。 The phase composition, microstructure and mechanical properties of Si_3N_4-TiC-Co composites were investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. It is found that TiC exists in the form of TiC and TiN, and Co exists in the form of CoSi. The mechanical properties of the composites were improved obviously with the addition of TiC and Co, the fracture toughness reached 7.2MPa · m ~ (1 / m), and the Y_2O_3 as sintering aids, the Si_3N_4 grains became fibrous.