Ablation behavior of graphite-film-modified C/C and C/C-(Hf, Ta)C-SiC composites

Abstract

In order to improve the ablation resistance of C/C composites, graphite films (GFs) and (Hf, Ta)C-SiC ceramic were introduced as high thermal conductivity and anti-oxidation components respectively. And the continuous heat conduction channel of GFs led to a 28 % improvement in the thermal conductivity of C/C-GFs composites. Meanwhile, the linear ablation rate of C/C-GFs composite decreased 26.9 %, also benefiting from the less defects of GFs. Furthermore, C/C-(Hf, Ta)C-SiC composite was fabricated through precursor infiltration pyrolysis method and the influence of solid solution degree of (Hf, Ta)C ceramic on the ablation resistance was investigated. It revealed that the full solid solution of (Hf, Ta)C ceramic promoted the generation of Hf₆Ta₂O₁₇ and (Hf, Ta, O) phases which possess high melting points. And more oxide phases coated on the composite surface, thus enhanced the ablation property of the C/C-GFs-(Hf, Ta)C-SiC composites.