Abstract: SiC-TiC composite powders were synthesized in argon atmosphere by a carbothermal reduction method using silica sol,glucose and TiO2 as the raw materials.The effects of different reaction temperatures on phase composition,particle size distribution and microstructure of SiC-TiC composite powders were discussed.The synthesized powders were characterized by X-ray diffraction,laser particle size analyzer and scanning electron microscope.Results showed that the suitable conditions for synthesizing SiC-TiC composite powders were at 1550 ℃ for 2 h.The SiC-TiC composite powders synthesized at 1550 ℃ were composed of a small amount of flaky particles,a certain amount of whiskers and a large number of nearly spherical particles.The growth mechanism of SiC whiskers in powder samples followed the vapor-solid (VS) mechanism.

Key words: SiC-TiC composite powders were synthesized in argon atmosphere by a carbothermal reduction method using silica sol,glucose and TiO2 as the raw materials.The effects of different reaction temperatures on phase composition,particle size distribution and microstructure of SiC-TiC composite powders were discussed.The synthesized powders were characterized by X-ray diffraction,laser particle size analyzer and scanning electron microscope.Results showed that the suitable conditions for synthesizing SiC-TiC composite powders were at 1550 ℃ for 2 h.The SiC-TiC composite powders synthesized at 1550 ℃ were composed of a small amount of flaky particles,a certain amount of whiskers and a large number of nearly spherical particles.The growth mechanism of SiC whiskers in powder samples followed the vapor-solid (VS) mechanism.