Ablation behavior of Y₂SiO₅/SiC coating for C/C composites under oxyacetylene torch

The ablation behavior of a Y₂SiO₅/SiC coating was investigated under oxyacetylene torch with two different heat fluxes. Applying the Y₂SiO₅/SiC coating, the ablation resistant property of C/C composites was improved obviously with heat flux of 2.38MW/m², and the linear and mass ablation rates were reduced by 56% and 90% after ablation for 60s, respectively. The good ablation resistance is attributed to the glassy protective layer of SiO₂ and Y₂O₃ that reduces heat transfer and oxidizing species transport. As heat flux increased to 4.18MW/m², increase of mechanical denuding and chemical erosion resulted in the degradation of the ablation resistance.