Ablation behavior of C/C composites matrix-modified by solid solution ceramic (Ta,Zr)C-SiC with different Zr/Ta ratios

To investigate the influence of (Ta,Zr)C on the ablation resistance of C/C composites, C/C-(Ta 0.5 Zr 0.5 )C-SiC, C/C-(Ta 0.33 Zr 0.67 )C-SiC, and C/C-(Ta 0.2 Zr 0.8 )C-SiC were prepared with different Zr/Ta ratios through high-solid-loading slurry impregnation combined with precursor infiltration and pyrolysis. The flexural performance and ablation resistance both improved with an increasing Zr/Ta ratio. Compared to C/C-(Ta 0.5 Zr 0.5 )C-SiC and C/C-(Ta 0.33 Zr 0.67 )C-SiC, the flexural strength of C/C-(Ta 0.2 Zr 0.8 )C-SiC increased by 74.17 % and 24.29 %, respectively. The mass ablation rate was reduced by 74.33 % and 81.02 %, while the linear ablation rate was reduced by 98.60 % and 97.65 % after 120 s of ablation, respectively. The variations in Zr/Ta ratios affected the formation, integrity, and performance of the microstructure, which was composed of a Zr-rich oxide skeleton combined with Ta-rich oxide binder within the Ta-Zr-O oxide layer on the composite surface, ultimately enhancing the overall ablation resistance of these composites.