Oxidation and Sublimation Ablation of C/SiC Ceramics in Hypersonic Environments

As a core thermal protection material for hypersonic vehicles, the ablation behavior of C/SiC ceramics in high-temperature air environments has long been a key challenge restricting their engineering applications. To systematically reveal the ablation evolution law of C/SiC in hypersonic environments, this study innovatively constructs a wide-temperature-range ablation theoretical model covering passive oxidation, active oxidation, and sublimation reactions and performs multiparameter coupled numerical simulation analysis. The research finds that an increase in heat flux leads to a synergistic growth trend in material surface temperature and mass ablation rate; an increase in gas flow enthalpy significantly raises the surface temperature, but the mass ablation rate shows an opposite decreasing characteristic; while changes in environmental pressure have a weak effect on surface temperature, they exhibit a significant positive correlation with the mass ablation rate. In addition, the study establishes a dimensionless ablation rate calculation system incorporating oxidation and sublimation processes. The research results provide important theoretical support and data reference for the performance optimization design and engineering application of C/SiC ceramic matrix composites in hypersonic environments.