Abstract: Continuous fiber reinforced ceramic matrix composites are considered highly promising thermal structural materials due to their low density, excellent mechanical properties, and outstanding oxidation and ablation resistance. In this study, a 2.5D woven carbon fiber preform was used as the reinforcement, and carbon fiber reinforced Zr matrix ceramic composites were fabricated by a hybrid technique utilizing both chemical vapor and reactive melt infiltration. The ablation behavior of the composites was investigated under oxyacetylene and oxy-kerosene environments. The results showed that after 100 s of ablation at 2 200 ℃ in an oxyacetylene flame, the composite structure remained intact, with linear and mass ablation rates of -0.74 μm/s and 1.51 mg/s, respectively. Under oxy-kerosene ablation at 1 300 ℃ for 100 s, the values for the linear and mass ablation rates are -0.99 μm/s and 11.48 mg/s. The ZrO₂+SiO₂ oxide protective layer formed on the surface after oxygen-acetylene ablation can effectively block oxygen diffusion into the matrix, endowing it with good ablation resistance. However, under oxygen-kerosene ablation conditions, the water vapor in the combustion gas reacts with SiO₂ to form gaseous products, resulting in a porous and loose SiO₂ protective layer. These pores become diffusion channels for oxidizing gases, leading to oxidation of the matrix and fibers, which consequently reduces erosion resistance of the composites.

Key words: carbon fiber reinforced Zr matrix ceramic composites, oxygen-acetylene ablation, oxygen-kerosene ablation, ablation mechanism