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℃ 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 30h at 1300℃ in air can be controlled below 1%.