Investigation on the ablation performance and mechanism of HfC coating modified with TaC

Abstract HfC coatings modified with different TaC contents were designed and successfully deposited on SiC-coated carbon/carbon (C/C) composites by supersonic atmosphere plasma spraying. The phase composition, morphology, and ablation resistance were surveyed, and the structural evolution of the oxide layer was studied as well. Results indicated that HfC coating with 10 vol.% TaC exhibited superior ablation resistance compared with the other compositions, as proved by the ablation rates and surface morphologies. The optical HfC/TaC volume fraction offers an oxide layer with adequate unmelted particles (HfO2 and Hf6Ta2O17) withstanding airflow scouring and moderate liquid phase (Ta2O5) impeding oxygen infiltration.