Plasma ablation behavior of C/C-(Hf_1-xZr_x)C composites prepared by precursor infiltration and pyrolysis

Five different C/C-(Hf_1-xZr_x)C composites were prepared by precursor infiltration and pyrolysis. The ablation behavior and microstructural evolution of these composites were investigated under plasma flame. The ablation resistance of (Hf_1-xZr_x)C modified C/C composites was improved, among which H5Z5 showed the best ablation resistance with mass loss rate and linear loss rate of −0.25 mg/s and 3.15 μm/s, respectively. During ablation, the ceramic phase oxidized to form a complete continuous Hf-Zr-O protective layer on the ablated surface. The barrier effect of the oxide layer effectively inhibited oxygen diffusion, thereby significantly decreasing the ablation rate of the composites.