Ceramic bearings possess superior thermal and mechanical properties but are prone to crack formation and lubricant degradation at high temperatures, driving the development of self-healing ceramics to improve their reliability and lifespan. This study investigates the high-temperature self-healing behavior of surface cracks in Al 2 O 3 -containing vanadium carbide (VC) particles and Al 2 O 3 pre-incorporated with both SiC and VC particles as healing agents. Bending tests show that the required healing time for reaching the strength of 500 MPa in Al 2 O 3 containing both VC and SiC achieves approximately 1/6000 times shorter than that in Al 2 O 3 -SiC composites without VC addition and significantly shorter than that of VC-added Al 2 O 3 . Excessive internal oxidation of pre-incorporated submicron- to micron-sized VC induces pore formation, reducing strength and hindering full-strength recovery. Formation of a SiO 2 protective layer against SiC oxidation mitigates pore formation. These findings provide a basis for designing ceramics capable of rapid, low-temperature self-healing without pore generation.
Oshiumi et al. (Sun,) studied this question.