Research progress in oxidation resistant coatings on Cf/SiC composites

Cf/SiC composites are considered as one of the most important candidates for aerospace thermal protection systems because of their low density, high specific strength, good thermal shock, oxidation and ablation resistance, and excellent high temperature strength retention. However, Cf/SiC composites are prone to oxidize at a temperature above 500 ℃ due to inevitable fabrication defects. So it is necessary to carry out effective oxidation protection for the composites. Oxidation resistant coating is an efficient technology to realize long-term oxidation protection. Based on harsh requirement of thermal protection systems, the research progress of anti-oxidation coatings for Cf/SiC composites was summarized, mainly focusing on the coating material systems and their preparation technologies. Improving the service temperature (≥1800 ℃) and bonding strength of the coatings is an important issue to be solved at present.The preparation of multi-functional coating with longer service time and higher service temperature, as well as oxidation resistance, water vapor corrosion resistance and even good heat insulation performance is an important direction for future development.