C/SiC/MoSi2-SiC-Si multilayer coating for oxidation protection of carbon/carbon composites
(C/C Composites Technology Research Center, State Key Laboratory of Thermostructural Composite Materials, Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: C/SiC/MoSi2-SiC-Si oxidation protective multilayer coating for carbon/carbon (C/C) composites was prepared by pack cementation and slurry method. The microstructure, element distribution and phase composition of the as-received coating were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results show that the multilayer coating was composed of MoSi2, SiC and Si. It could effectively protect C/C composites against oxidation for 200 h with the mass loss of 3.25% at 1873 K in static air. The mass loss of the coated C/C composites results from the volatilization of SiO2 and the formation of cracks and bubble holes in the coating.
Key words: C/C composites; C/SiC; MoSi2; SiC; multilayer; coating; oxidation