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

Interfacial cracking in the joint between a glass-ceramic sealant and a 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 at the crack front of a crack placed at the highly stressed interfacial region between a glass-ceramic sealant and a metallic interconnect in the given pSOFC stack for each stage.  The critical crack or defect size at the interface of the joint of glass-ceramic sealant and metallic interconnect in the given pSOFC stack is determined by comparing the calculated energy release rates with the experimental measurements of interfacial fracture energy of the glass-ceramic/metallic interconnect joint.