Effect of TiB₂ on the self-crack-healing ability of SiC-Si coating at 1300 °C

TiB₂-SiC-Si coating was prepared on the surface of C/C composites by slurry immersion pyrolysis combined with gas-phase silicon infiltration method. The influence of the addition of TiB₂ on the oxidation resistance of Si-SiC coating was studied. TiB₂ significantly increases the oxidation protection time of the SiC-Si coating at 1300 °C. The TiB₂ modified Si-SiC coating displayed a weight increase (0.03%) after oxidation at 1300 °C for 300 h, while the unmodified coating had a weight loss of 0.84% after oxidation at 1300 °C for 100 h. It is found through experiments that doping TiB₂ produces more molten glass phases when the ceramic coating is oxidized at 1300 °C, which effectively heals cracks and plays a good protective performance.