Oxidation protective TaB₂-SiC gradient coating to protect SiC-Si coated carbon/carbon composites against oxidation

To improve the oxidation protection ability of the TaB₂-based coatings, an oxidation protective TaB₂-SiC gradient coating was prepared by in situ reaction method on SiC-Si coated C/C composites, which consists of a TaB₂-SiC-Si middle buffer layer and a TaB ₂-SiC outer layer. The TaB₂-SiC/TaB₂-SiC-Si/ SiC-Si coating could protect the C/C substrate from oxidation at 1773 K for 1360 h. During oxidation, a protective silicate glass layer consisted of an upper Ta-Si-O glass layer and a lower SiO₂ glass layer would gradually formed on the surface of the coated C/C, which is responsible for the excellent oxidation resistance of the coated C/C.