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

• Y2SiO5/SiC coating was prepared by pack cementation and supersonic plasma spraying.
• Ablation behavior of Y2SiO5/SiC coating was investigated under oxyacetylene torch.
• Ablation resistant property of C/C composites was improved greatly under 2.38 MW/m2.
• A glassy layer of SiO2 + Y2O3 coated on the surface with the heat flux of 2.38 MW/m2.

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 2.38 MW/m2, and the linear and mass ablation rates were reduced by 56% and 90% after ablation for 60 s, 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 4.18 MW/m2, increase of mechanical denuding and chemical erosion resulted in the degradation of the ablation resistance.