Effect of PyC-SiC double-layer interface on ablation behaviour of impacted CVD-SiC_nws/HfC coating

To optimize the impact-ablation resistance of SiC_nws@PyC/HfC coating, PyC-SiC double-layer interface phase was introduced. After impacting test, the crack widths of SiC_nws@PyC-SiC/HfC were much lower than that of SiC_nws@PyC/HfC coating. The impact-ablation resistance of SiC_nws@PyC-SiC/HfC coating was better than that of SiC_nws@PyC/HfC coating. The good impact-ablation resistance SiC_nws@PyC-SiC/HfC coating attributed to the two-grade pull-out reinforcement effect, self-sealing function of Hf-Si-O glass generated from oxidation of SiC_nws@PyC-SiC core-shell structure and the precipitation of HfO₂ grains from Hf-Si-O glass under ablation environment.