三维针刺C/SiC在等离子焰中的烧蚀行为

Plasma Arc Ablation Behavior of 3D Needled C/SiC Composites

采用CVI制备了三维针刺C/SiC复合材料,利用等离子烧蚀对复合材料的烧蚀性能进行了分析。结果表明:复合材料的线烧蚀率和质量烧蚀率分别为131.3μm/s和74.2g/s,对应的标准偏差分别为4.9μm/s和4.7mg/s。微结构观察显示烧蚀表面不同区域其烧蚀机理不同,烧蚀中心以升华烧蚀为主,过渡区主要是升华烧蚀和等离子流的剪切剥蚀为主,而烧蚀边缘则以热氧化为主。

3D needled C/SiC composites were prepared by chemical vapor infiltration process. And the ablation behavior of the composites was investigated by plasma arc. Results showed that the linear ablation rate and mass ablation rate were 131.3 μm/s and 74.2 mg/s,with standard deviations of 4.9 μm/s and 4.7 mg/s respectively. Microstructural observations revealed that the ablation processes were varied at different position. At the ablation center,the ablation of the composites was dominated by sublimation. Between the ablation center and the edge, the ablation of the composites was the coupled result of sublimation and shearing peel-off by plasma flow. At the edge, the ablation of the composites was dominated by thermo-oxidation.