Figure 1.

Schematic illustrations for oxidation-induced crack-gap filling models in self-healing composites. (a) Macroscopic crack-gap filling behavior for self-healing ceramics, (b-c) bridging model: microscopic filling behavior near the crack mouth with large crack opening displacement, (b) for SiC particles composite, (c) SiC whiskers composite, and (d) monolithic SiC ceramics. (e) Tip-to-mouth filling model. (f) 3D structure of remaining cracks in the bridging model. The actual fracture will be described by the mixed models shown above. Thus, the bridging model and tip-to-mouth filling model correspond to the upper and lower limit strengths of the healed ceramics, respectively.