Effect of surface ablation products on the ablation resistance of C/C–SiC composites under oxyacetylene torch

Single and cyclic ablations under oxyacetylene torch with 2380 ± 10% kW/m2 heat flux were performed to evaluate the effect of ablation products on the ablation resistance of carbon/carbon – silicon carbide (C/C–SiC) composites separately. As a result of the accumulation of noncrystalline SiO2 enwrapped SiC, ablation resistance of prepared composites was enhanced with time prolonging under single ablation while it was improved more significantly under cyclic ablation. The ablation products played several key roles during ablation: decreasing surface temperature, acting a barrier to oxidizing species attack and conglutinating defective ablated carbon fibers.

► Single and cyclic ablation tests were used to evaluate the effect of ablation products. ► C/C–SiC composites displayed better ablation resistance under cyclic ablation. ► Ablation products of C/C–SiC composites could decrease the surface temperature. ► Ablation products accumulated faster under cyclic ablation. ► Bond between ablation products and sample surface was good.