Oxidation protection of CrSi2-HfB2-SiC/SiC coating for graphite in variable-temperature environment

The application of carbon materials in actual environment requires that they can resist oxidation in variable-temperature environment. CrSi2-HfB2-SiC/SiC coating was synthesized on graphite surface to protect it from oxidation at variable temperature. The anti-oxidation properties of the coated samples were tested and analyzed in variable- high-temperature environment from 1700 to 1500 ℃ and a wider variable temperature environment from room temperature to 1700 ℃. Experimental results reflect that the CrSi2-HfB2-SiC/SiC coating can not only protect graphite from oxidation in 1700→1500 ℃, but also protect it reliable service in room temperature→1700 ℃. Pre-oxidation can reduce the oxidation damage of the coating in variable-high-temperature environment.