Ablation behavior of ZrC and ZrO₂ coatings on SiC coated C/C composites under oxyacetylene torch with different heat fluxes

In this work, ZrC and ZrO₂ coatings were prepared on SiC-coated carbon/carbon (C/C) composites by supersonic atmospheric plasma spraying. Their ablation behavior was investigated and compared under different heat fluxes to design multilayer anti-ablation structural coating. Results shown that ZrO₂ coating exhibited denser oxide layer and lower mass consumption after ablation. According to their microstructure and thermal analysis, possible reasons can be ascribed to higher surface temperature and lower melting point of ZrO₂ coating, which made the scale easier to be sintered during ablation. Moreover, the ablated ZrC coating presented particle accumulation structure at the initial ablation stage, hence causing the consumption from mechanical denudation to occur in these particles preferentially rather than sintering.