Multilayer and multi-component oxidation protective coating system for carbon/carbon composites from room temperature to 1873 K

• B2O3-modified MoSi2–CrSi2–Si/B-modified SiC coating was designed and prepared.
• The coating has the self-sealing ability from room temperature to 1873 K.
• The coating can protect C/C composites from room temperature to 1873 K.
• The coating can ensure 30 thermal cycles between room temperature and 1873 K.

A multilayer B2O3-modified MoSi2–CrSi2–Si/B-modified SiC coating system was prepared on the surface of carbon/carbon (C/C) composites by a three-step pack cementation method. The microstructure, oxidation resistance and thermal cycling test of the multilayer coating were studied. The results show that the coating system exhibits good oxidation resistance from room temperature to 1873 K. It can protect the C/C composites from isothermal oxidation in air at 1173 K for 150 h or 1873 K for 900 h, respectively. It can also resist 30 thermal cycles between 1873 K and room temperature.