关键词: 微观结构, TiSi₂, 原位反应, SPS, 复合材料

Abstract: TiSi₂-SiC and TiSi₂-SiC-Ti₃SiC₂ composites were in situ fabricated by spark plasma sintering using commercially available Si, Ti, C and TiC as starting materials. The phase constitutes and microstructures of the composites were analyzed by XRD, FESEM and TEM. It shows that the TiSi₂ grains are larger than 1μm and SiC particles in the range of 200--300nm uniformly distribute
in the TiSi₂ matrix. The hardness, fracture toughness and bending strength of TiSi₂-SiC composites increase with the SiC contents increasing. The introduction of Ti₃SiC₂ enhances the mechanical properties of
TiSi₂-SiC-Ti₃SiC₂ composite greatly. In addition, the introduction
of SiC and Ti₃SiC₂ have little effect on the electrical conductivity and thermal conductivity of TiSi₂ -SiC composites tested at the elevated temperature.

Key words: microstructure, TiSi₂, in situ reaction, SPS, composite