A SiC-HfSi₂ anti-ablation compound coating of carbon/carbon composite

To improve the ablation resistance of carbon/carbon (C/C) composite, a silicon carbide-hafnium silicide (SiC-HfSi₂) coating was prepared on the C/C composite surface by a pack cementation technique. The ablation behavior of the coated C/C composite was evaluated by the oxyacetylene flame. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were also applied to analyze the surface and cross-section morphologies, element distribution as well as the phase composition of coatings before and after ablation, respectively. The results show that cluster-like dioxide silicon nanowires occurred on the ablated surface for the SiC-HfSi₂ coated C/C composite. Meanwhile, the mass ablation rate of SiC-HfSi₂ coated C/C composite is reduced by about 85.6% compared with the C/C composite.