Effect of SiC_nws@BN core shell upon impact-ablation performance of HfC coating on C/C composites

To improve the thermal protection performance of HfC coating subject to impact, SiC_nws@BN core-shell nanowire reinforced HfC coating was fabricated by chemical vapor deposition and compared to the SiC_nws@PyC/HfC coating. The experiments showed that the ablation resistance of SiC_nws@PyC/HfC coating decreased significantly. In comparison, the ablation resistance of SiC_nws@BN/HfC coating was barely affected by impact. A dense oxide layer was formed on the surface of SiC_nws@BN/HfC coating after impact and ablation. The shrinking and self-healing effect of SiC_nws@BN during oxidation process was investigated, which explained the formation process of dense oxide layer.