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以碳毡为骨架,采用CH_3SiCl_3—C_2H_2—N_2—H_2,用共沉积方法制备了C-SiC纳米基复合材料,并研究了其结构与氧化性能。Si在基体中分布是不均匀的,在偏光下纳米基体由一些不同亮度的环组成,Si在暗层和亮层中的浓度分别为0.6at%和1.8at%。由于Si的加入,热解碳的晶体尺寸Lc从11.6nm降到3.31nm。在800℃、1000℃和1200℃分别氧化1小时后,C-SiC纳米基复合材料抗氧化性能明显优于高纯石墨。
C-SiC nanocomposites were prepared by coprecipitation method using CH 3 SiCl 3 -Cl 2 C 2 H 2 -N 2 -H 2 as carbon fiber matrix. The structure and oxidation properties of C-SiC nanocomposites were also studied. The distribution of Si in the matrix is inhomogeneous. Under polarized light, the nano-matrix consists of rings with different brightness. The concentrations of Si in dark and bright layers are 0.6at% and 1.8at%, respectively. Due to the addition of Si, the crystal size Lc of pyrolytic carbon dropped from 11.6 nm to 3.31 nm. After oxidation at 800 ℃, 1000 ℃ and 1200 ℃ for 1 hour respectively, the oxidation resistance of C-SiC nano-matrix composites is obviously better than that of high purity graphite.