Abstract
The competition between crack self-healing and crack propagation induced by service stress in self-healing materials was investigated in the present study. Especially, it was succeeded that assessment on the displacement at the three-point bending load allows the time which crack propagation is arrested by self-healing to be evaluated. Although the bending stress of 70 MPa induced crack propagation form the pre-crack in alumina fiber reinforced self-healing alumina containing SiC interlayer as healing agent, which is typical self-healing fiber reinforced ceramics (shFRC), the crack propagation is arrested by self-healing effect for about 2200 s at 1100℃ in oxidizing atmosphere. Only self-healing progressed after the arrest and the complete strength recovery was attained for 1 h. From the above result and similar results at 1000℃ and 1200℃, the time which crack propagation is arrested by self-healing exhibits Arrhenius relation as a function of temperature. Therefore, the self-healing effect for crack propagation was found to be directly affected by oxidation reaction rate of SiC.
