Simulation of Interfacial Cracking of the Joint between Glass-Ceramic Sealant and Metallic Interconnect in a Planar Solid Oxide Fuel Cell Stack

Abstract

Interfacial cracking in the joint between glass-ceramic sealant and metallic interconnect under thermal stresses is characterized for a prototypical planar solid oxide fuel cell (pSOFC) stack, using finite element analysis (FEA). A three dimensional FEA model is constructed for a multiple-cell stack to perform thermal stress analysis at both steady operation and shutdown stages and to locate the highly stressed region in each component. Stress intensity factor and energy release rate for fracture are calculated for each stage at the crack front of a crack placed at the highly stressed interfacial region between glass-ceramic sealant and metallic interconnect. The critical crack/defect size at the interface of such a joint in the given pSOFC stack is determined to be 70 μm by comparing the calculated energy release rates with the experimental measurements of interfacial fracture energy.