ZrB2-SiC ceramics coating for Cf/SiC composites: Microstructure and anti-ablation mechanism

Highlights: • ZrB₂-SiC coatings were prepared by brushing process. • Anti-ablation mechanism of ZrB₂-SiC coatings coated C_f/SiC composites was studied. • The linear and mass ablation rates were much lower than that of uncoated samples. • ZrB₂-SiC coatings could improve the ablation resistance of C_f/SiC composites. In order to improve the oxidation behavior of C_f/SiC composites in oxygen atmosphere at high temperatures, ZrB₂-SiC ceramics coatings were prepared on C_f/SiC composites by using a brushing process. The composition of the coating and the microstructure of the reaction products were investigated by XRD and SEM; the ratio of ZrB₂: PCS was studied, and the anti-ablation test was used to analyze the stability of coating at higher temperature. The results showed that the coatings were homogenous by this method. The coatings could improve the stability effectively, when the ratio of ZrB₂: PCS was 5:1, the coatings had the best interface combine intensity. Compare with the uncoated C_f/SiC samples, the coated C_f/SiC samples exhibited better anti-ablative property, the coating prevented the matrix from ablation efficiently.