摘要
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 cofficient 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.
基金
The authors greatly acknowledge the financial support from the National Natural Science Foundation of China(Grant No.51972027).
