Effect of CVD SiC coatings on oxidation behaviors of three dimensional C/SiC composites

Two kinds of multilayer CVD SiC coatings were prepared by LPCVD on a three dimensional C/SiC composites. The surface and cross section micromorphologies of the coatings were analyzed by SEM. The oxidation behaviors of the composites with multilayer coatings at 1300°C in air were studied. The interlayer gaps of the multilayers can be effectively controlled by the slow deposition. The multilayer coatings prepared by the slow deposition were integrated as a whole which can improve the oxidation protection property evidently. The weight loss of the 3D C/SiC protected with the multilayer CVD SiC coatings prepared by slow deposition after oxidation for 30 h at 1300°C in air can be controlled below 1%.