Comparative ablation behaviors of C/SiC–ZrC and C/SiC–HfC composites prepared by ceramization of carbon aerogel preforms

Abstract

Novel carbon aerogels were used as matrix precursors to fabricate C/SiC–ZrC and C/SiC–HfC composites through their reactions with molten ZrSi2 and HfSi2, respectively. The ablation behaviors of the two composites were investigated comparatively. The C/SiC–ZrC has a lower linear ablation rate at 2200 °C but a higher value at 2500 °C. It can be attributed to the milder exfoliation of the formed SiO2–ZrO2 with more glass phase than SiO2–HfO2 at 2200 °C. However, the solid HfO2 skeleton formed on the ablation surface has superior anti-peeling capability than ZrO2 at 2500 °C.