Anti-oxidation property of the ZrB₂–SiC–Si-coated low-density C/C composites

ZrB₂–SiC–Si-coated low-density C/C composites were prepared by a low-cost and simple pack cementation. The microstructure, oxidation and ablation resistance of the ZrB₂–SiC–Si-coated low-density C/C composites have been investigated. The ZrB₂–SiC–Si-coated low-density C/C composites exhibited good oxidation, thermal shock and ablation resistance at high temperature. The mass loss of the coated low-density C/C samples was only 0.68% at 1773 K for more than 260 h. The mass gain of the coated low-density C/C samples was 1.5% after 50 thermal cycles. The coated low-density composites could also withstand from ablation at 2573 K for 60 s under oxyacetylene flame. The good oxidation and ablation resistance of the composites are mainly attributed to the interlocking-pattern structure and the protection of the oxide layer.