C/SiC 复合材料碳纤维氧化烧蚀机理研究

With the advantages of high strength and high temperature resistance, C/SiC composites have been widely used in aerospace field. In this paper, the oxidative ablation in C/SiC composites is studied experimentally and simulatively. Therefore, oxidation kinetics mechanism of carbon fiber is researched by both simulation and experimental in this article. Firstly, the oxidation weight loss rate of carbon fiber at different temperature and oxygen partial pressure is measured experimentally, and the calculation relation is fitted. Secondly, based on calculation relation and lattice Boltzmann method (LBM), the oxidation ablation model of carbon fiber is established. Finally, the oxidation ablation characteristics of C/SiC composites are simulated. The results show that with the increase of temperature, the controlling factor of ablation rate will gradually change from the chemical reaction rate to the diffusion rate of gas. The ablation rate of pure carbon fiber is about 3-27 times that of carbon fiber in C/SiC composites, and the higher the temperature, the greater the difference is. This study provides a theoretical basis for improving the oxidation resistance of C/SiC composites under high temperature oxygen atmosphere.