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 TaB2-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. (C) 2014 Elsevier Ltd. All rights reserved.