The crack-healing behavior of SiC ceramics with a large crack width has been studied as functions of coating and heattreatment. The SiO2 colloid coating was carried out in two types of hydrostatic pressure coating and roll coating. The crackhealingwas carried out one hour at 1173 K in air. The crack part formed SiO2 oxides until the critical time through ahydrostatic pressure method. The crack did not heal anymore if it exceeded the critical times. The crack part and the basepart have many O components and Si components regardless of the times of coating and heat treatment. Furthermore, thecombined hydrostatic and rolling coating method did not have nearly an effect on crack-healing for a large crack width over1.4 µm. A study for more effective healing of a large crack width must be carried out in the future.

Keywords: Crack Healing, SiC Ceramics, SiO2 Colloid, Coating Method