High-temperature erosion resistance of ZrB₂-based ceramic coating for lightweight carbon/carbon composites under simulated atmospheric re-entry conditions by high frequency plasma wind tunnel test

A double-layers ZrB₂-based ceramic coatings containing ZrB₂, MoSi₂, SiCw and borosilicate glass were prepared on lightweight and porous ZrB₂-modified carbon-bonded carbon fiber composites (CBCFs/ZrB₂) by a trace oxygen sintered technology. The high-temperature erosion resistance of the coated CBCFs/ZrB₂ was investigated under simulated atmospheric re-entry conditions by a high frequency plasma wind tunnel test with a heat fluxes of 1.3 MW/m and stagnation pressure of 1.2kPa. The results showed that the coated composites exhibited excellent ablation resistance for 800 s and the different positions of coating exhibit different response temperatures and microstructures. After ablation, the micrographs of marginal position show more compact than central position at sample surface. In addition, the side of the samples exhibits crack region, B₂O₃ precipitates region and virgin coating region.