Ablation behavior of HfC protective coatings for carbon/carbon composites in an oxyacetylene combustion flame

HfC protective coatings with different structures were deposited on C/C composites by CVD. The microstructures, ablation properties and ablation behavior of the HfC coatings are investigated. Results show that the HfC coating with particle-stacked structure exhibits the favorable ablation resistance. The higher mass ablation rates of HfC coatings with columnar-arranged structure are contributed to the peeling of coatings. In different stages of ablation, the ablation rate of HfC coating is controlled by various mechanisms. The formation of porous HfO2, HfCxOy layer and molten HfO2, as well as the consumption of heat, are all beneficial to the protection for C/C composites.

The HfC coatings can improve the ablation resistance of C/C composites effectively, and the HfC coatings with particle-stacked structure exhibit the favorable ablation resistance.Figure optionsDownload as PowerPoint slideHighlights
► HfC coatings with different structures were deposited on C/C composites by CVD.
► HfC coatings with particle-stacked structure have the favorable ablation resistance.
► The ablation rate of HfC coating is controlled by various mechanisms.