Ablation of C/SiC-HfC composite prepared by precursor infiltration and pyrolysis in plasma wind tunnel

Abstract

Carbon fiber reinforced silicon carbide–hafnium carbide (C/SiC–HfC) composite was prepared by precursor infiltration and pyrolysis process. Then, ablation behavior of C/SiC–HfC was evaluated in plasma wind tunnel. It was found that oxide layer formed during ablation significantly influenced the surface temperature. Formation of dense HfO₂–SiO₂ layer under low heat flux led to stable surface temperature. Silica (SiO₂) on the surface was gradually consumed when heat flux increased, resulting in conversion of HfO₂–SiO₂ on the surface to HfO₂. Converted HfO₂ with high catalytic coefficient absorbed more energy, causing gradual increase in the surface temperature. Formed oxide layer was destroyed at high heat flux and high stagnation point pressure. After carbon fiber lost the protection of HfO₂–SiO₂ layer, it burned immediately, leading to surface temperature jump.