Ablation Behavior of HfC Coating Prepared by Supersonic Plasma Spraying for SiC-Coated C/C Composites

In order to improve the ablation resistance of C/C composites HfC coating was deposited on the surface of SiC-coated C/C composites by supersonic atmospheric plasma spraying. The microstructure and morphology of the different coatings were characterized by Scanning Electron Microscopy, X-ray diffraction. The ablation test of samples was carried out with an oxyacetylene torch. The coating exhibits dense structure and good ablation resistance. After ablation for 30s, the linear and mass ablation rates of the coating are 0.59 μm/s and 0.6 mg/s, respectively. In ablation centre region, a HfO2 layer is formed on the surface of sample after 30s ablation, and it can protect C/C composites from ablation.