Preparation and Anti-oxidation Behavior of Si-C-B Self-healing Coating on C/SiC Composite

Modification of SiC coating was carried out with B and BC_x prepared by chemical vapor deposition(CVD),SiC/B/SiC and SiC/BC_x/SiC multi-layer self-healing coatings were prepared on a two-dimensional C/SiC composite.The surface and cross section morphologies of the multi-layer coat- ings were analyzed by SEM.Oxidation were carried out in static air at 700℃.The results show that the B203 glass produced by oxidation of B or BC_x can seal the cracks existed in the coating well, the kinetics of oxidation is controlled by diffusion of oxygen through the micro-cracks and B_2O_3 glass layer;SiC/BC_x/SiC-C/SiC composites have lower weight loss during the oxidation and higher strength retention after oxidized for 10h.