Mechanical and anti-ablative preformances of C/C-SiC composites modified by ZrC

Carbon fiber needling preform was used to prepare C/C-SiC and C/C-SiC-ZrC ceramics matrix composites by precursor infiltration and pyrolysis (PIP) process respectively. The microstructure, mechanical and ablation properties of materials were analyzed and compared. The results show that the composites produced by the method have sufficient filling and homogeneity distribution of ceramic phase. The in-plane flexural strength, compression strength through thickness direction and interlaminar shear strength of C/C-SiC-ZrC are all lower than the corresponding properties of C/C-SiC. C/C-SiC-ZrC shows better anti-ablative preformances compared with C/C-SiC after ablation at 2 200 ℃ for 600 s, the linear ablation rate is reduced by 43.8% and the mass ablation rate is reduced by 25%. During ultra-high temperature stage, the ZrC and SiC in the matrix of C/C-SiC composites are oxidized into ZrO₂ and SiO₂, which form a kind of viscous binary glassy mixture. The mixture could effectively prevent oxidizing atmosphere into the matrix.