Growth mechanism and ablation behavior of CVD-HfC coating on the surface of C/C composites and CVD-SiC coating

HfC coatings were deposited on the surface of carbon/carbon (C/C) composites and CVD-SiC coating by low-pressure chemical vapor deposition (CVD), respectively. The effects of two substrates on the microstructure, phase composition and preferred orientation of HfC coatings were investigated in detail. Results showed that HfC coatings deposited on two substrates inherit their own substrate surface characteristics. After ablation for 90 s, the HfC coating prepared on CVD-SiC coating has better ablation resistance under oxyacetylene flame with heat flux of 2.4 MW/m(2), because the transition layer can effectively relieve the damage caused by thermal stress.

Automated summary

The HfC coatings deposited on the two substrates inherit their own substrate surface characteristics, with the HfC coating prepared on CVD-SiC coating showing better ablation resistance after ablation for 90 s under an oxyacetylene flame with heat flux of 2.4 MW/m(2), thanks to the transition layer effectively relieving thermal stress-induced damage.