Effect on BN interphase thickness upon SiC_nws@BN/HfC coating performance under impact and ablation environment

To inhibit the negative influence of impact on ablation performance of HfC coating reinforced by SiC nanowires (SiCnws/HfC coatings), BN interphases were fabricated and introduced into SiCnws/HfC coatings by chemical vapor deposition. The effect on BN interphase thickness upon SiCnws@BN/HfC coatings performance under impact-ablation environment was investigated. The interphase thickness was adjusted by changing the deposition time of BN. Impact and ablation tests were carried out by drop hammer and oxyacetylene ablation devices. Among the prepared coatings, the one with 150 +/- 20 nm thickness interphase possessed a good performance under impact test, of which the crack propagation path exhibited a significant deflection. After ablation, the coating could still maintain intact surface, because the interphase thickness of 150 +/- 20 nm was appropriate to ensure the toughness of the coating and to avoid the porous structure formation.