Ablation behaviour of the CVD-(ZrC/SiC)3 alternate coating on C/C composites under oxyacetylene torch with different heat fluxes

Abstract

The (ZrC/SiC)3 alternate coating prepared on C/C composites by CVD were tested using an oxyacetylene torch with the heat fluxes of 2.38 and 4.18 MW/m2. Results showed that the coating exhibited great ablation resistance under both low and high heat fluxes. Under heat flux of 2.38 MW/m2, the ablation and oxidation occurred layer by layer, while the six layers of coating were reserved after ablation. The SiO2 phase and transitional ZrCxOy layer were formed, providing an effective protection. As the heat flux increased to 4.18 MW/m2, the ablation became more serious while the oxide layer still kept intact on C/C substrate after ablation. Dense and stable layered ZrO2 layers covered on C/C composites after the rapid consumption of SiC layers, which could resist the flame scouring. The (ZrC/SiC)3 alternate coating was demonstrated to have potential in applications under different ablation conditions.