Abstract: The ultra-high-temperature composites C/C-SiC-ZrB₂ were prepared by slurry impregnation method. The composites consist of the carbon fiber as the reinforced phase, C and SiC as the matrix, and the micro-particle ZrB₂ as the ultra high temperature phase. The ablation resistance properties of the composites were assessed by arc wind tunnel testing. The ablation mechanism was studied through XRD, SEM and EDS measurements. The results indicate that compared with C/C-SiC composites, the C/C-SiC-ZrB₂ composites show better ablation resistance properties, and the properties increases with the content of ZrB₂ increase. A ZrO₂-SiO₂ glassy melting layer formed at high temperature plays an important role in antioxidant ablation.

Key words: ultra-high-temperature composites, C/C-SiC-ZrB₂ increase, ablation resistance properties, ablation mechanism