Chemical Fracture of a Ceramic Oxygen Ion Conductor with Periodic Edge Cracks

摘要

This paper investigates multiple surface cracking in an oxygen ion conducting ceramic undergoing lattice expansion. We assume that the cracks are parallel and periodically distributed, which allows detailed examination of the effects of multiple crack interactions as well as analytical treatment of the problem. A singular integral equation method is used to calculate the chemical stress intensity factor (CSIF) at the crack tips in the framework of linear chemo-elastic fracture mechanics. The effect of crack spacing or crack density on the CSIF is examined using the numerical results for the periodic cracks at the cathode side of an oxygen ion conducting ceramic under the constrained flat conditions. It is found that the CSIF can be reduced dramatically by decreasing the crack spacing (or increasing the crack density). Hence, the fracture resistance of ceramic oxygen ion conductors can be enhanced with high density multiple surface cracks.