Nanowire-toughened CVD-SiC coating for C/C composites with surface pre-oxidation

A combination method of surface pre-treatment and SiC nanowire toughening was proposed to solve the problems of easy cracking and peeling of the SiC coating on carbon/carbon composites. The composition and microstructure of the as-prepared coating were analysed by XRD and SEM. After introducing the buffer layer toughened by SiC nanowire, the bonding force between substrate and coating increased from 6.0 to 18.5 N. After thermal shock between room temperature and 1773 K for 15 cycles, the mass loss of the sample decreased by 67%. The enhancements of interface bonding and thermal shock resistance of the CVD-SiC coating are mainly due to the formation of the nanowire-toughened buffer layer, which could improve the matching compatibility between C/C substrate and CVD-SiC coating.