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

Abstract

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 TaB2–SiC outer layer. The TaB2–SiC/TaB2–SiC–Si/SiC–Si coating could protect the C/C substrate from oxidation at 1773K for 1360h. 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.