Ablation behavior of HfC modified carbon/carbon composites

Carbon/carbon composites(CVC) with different amounts of HfC were prepared by the metal salts solution dipping-thermal gradient CVI method. Their ablation properties were tested in oxyacetylene flame with the gas of high velocity. The forming of HfC in C/C composites was investigated by DSC-TG method. The microstructure was studied by SEM, EDS and XRD. It was found that the liner ablation rate of HfC modified Carbon/Carbon composite is much lower than that of the carbon/carbon composites without HfC modified, because the HfC restrained the oxidization of carbon in composites and repaired the gaps on ablation, resulted in the decrease of thermochemical ablation and mechanical erosion of the composites.