Ablation mechanism of SiC coated C/C composites at 0° angle in two flame conditions under an oxyacetylene flame

摘要

A SiC coating was prepared on the surface of C/C composites by pack cementation and composites were ablated under an oxyacetylene flame in two flame conditions (HF1 and HF2). The gas fluxes of O_2 and C_2H_2 in HF2 were higher than those in HF1. And the ablation angle was 0° during ablation. The ablation mechanism of composites was analysed. Results showed that SiC coated C/C composites had good ablation resistance in HF1, while SiC coating lost protection in HF2. The influence of oxyacetylene flame on the physico-chemical properties of SiC and SiO_2 was the main reason for different ablation behaviours.