碳纤维增强C—SiC梯度基复合材料研究

采用ＣＶＩ工艺均热法共沉积技术制备了碳纤维增强Ｃ－ＳｉＣ梯度基复合材料。Ｃ和ＳｉＣ的原料氛分别是Ｃ２Ｈ２ｔ ＣＨ３ＳｉＣｌ３，Ａｒ和Ｈ２分别是载流和稀释气体。基体微观结构的变化通过控制原料气体的成分配比藜得。测试了材料的力学性能、抗氧化性能和摩擦磨损性能。利用金相技术、电子探针成分分析技术、ＴＥＭ和ＳＥＭ技术观察和分析了材料的微观结构。试验结果表明，这种材料的组织结构特点是：在微观上是梯度的，即围

The Studies of C/C-SiC Gradient Matrix Composites

C-SiC Gradient Matrix Composites (GMCs) have been prepared by CVI with C and SiC cedeposition.CH3SiCl3 liquid and C2H2 gas are used as the sources, and Ar and H2 gases are used as the carrier and dilutant gases, respectively. The GMCs have been achieved through the compositions of source gases gradually varying from C2H2 to CH3SiCl3 in the continuous process. Oxidation resistance, wear and mechanical testing are carried out and the microstructures are observed by optical microscopy, electron-probe microanalysis,TEM and SEM. These results show that, macroscopically, this material is homogeneous but microscopically, the matrix composites around each fiber vary continuously, and the oxidation resistance of the material is significantly superior over C/C material because SiC particles are incorporated into carbon matrix as an inhibitor and finally SiC coating is formed on the outside of matrix sheaths to protect carbon surface from oxidation. This is one of the most promising thermostructural materials owing to its lowdensity, better mechanical properties and good resistance to oxidation.