Figure 3
Self-healing in Al2O3/SiC composites and effect of healing activator network. (a) Oxygen penetrates cracked surfaces, and oxidizes SiC to SiO2 (defined as the inflammation stage). (b) Al2O3 and MxOy dissolve into SiO2 to form a mechanically weak, low-viscosity supercooled melt, which completely fills irregularly shaped gaps (defined as the repair stage). (c) Mechanically strong crystals nucleate and grow in the supercooled melt (defined as the remodelling stage). (d) Scanning electron micrograph of an indentation crack filled by healing agent in a ceramic doped with 0.2 vol.% MnO and healed at 1,273 K for 1 h. (e) Mn-rich healing activator network bio-inspired by lacuna-canalicular networks. (f) Compact bone with networks of blood vessels and lacuna-canaliculi containing osteocytes.
