Anti-oxidation mechanisms of the SiC/ZrB₂-MoSi₂ coating on the carbon/carbon composites

The anti-oxidation coatings of SiC/ZrB₂-MoSi₂ on the carbon/ carbon composites were prepared by pack cementation and slurry painting. The coating microstructure, performance and the anti-oxidation mechanisms were investigated by SEM, XRD, etc. The results show that the inner coating of SiC can eliminate the thermal expansion mismatch between carbon/carbon composites and the outer coating of ZrB₂-MoSi₂. The coating mass loss of ZrB₂-MoSi₂ prepared by slurry painting with a lot of craze cracks is 3.58 % after 10 h in air at 1500 ℃. The coating exhibits self-healing performance, excellent anti-oxidation ability and thermal shock resistance.