Ablation resistance of ZrC/SiC gradient coating for SiC-coated carbon/carbon composites prepared by supersonic plasma spraying

A novel SiC/SiC–ZrC gradient coating system was prepared on the surface of carbon/carbon (C/C) composites by supersonic plasma spraying. The microstructure and ablation resistance of the gradient coating were studied. The results show that strong bond was formed between SiC inner coating and SiC–ZrC gradient coating. The coating system exhibits good ablation resistance under oxyacetylene ablation for 60 s. Compared with the single SiC-coated C/C composites, the linear and mass ablative rate decrease 54.2% and 62.5%, respectively. The chemical ablation and mechanical denudation are dominating on the central region and chemical ablation is dominating on the transition region and border region.