ABSTRACT
In this paper, cracking behavior of the SiC coating deposited on the surface of C/C composites during the cooling process after the coating treatment is discussed. In the analysis, the thermal residual stress induced in the SiC coating was calculated by use of the FEM and the coating crack spacing and crack width were predicted. The predicted results were then compared with the experimental observations as a function of coating thickness. It was found through the comparison that : (1) the coating cracks propagate not only in the SiC coating but also into the C/C substrate and the substrate cracks have a profound influence to the stress distribution in the coating. (2) The saturated crack spacing and crack width is precisely predicted from the maximum interfacial normal stress at the center of adjacent cracks.
