Mechanical behavior of YSZ-glass composite seals for solid oxide fuel cell application

Abstract

The long-term operation of solid oxide fuel cell stack critically depends on the joint strength between cells and interconnect alloy. In this work, 20 wt% YSZ (Y 2 O 3 stabilized ZrO 2 ) was added into different kinds of glass to form H1-20 and H4-20 composite seals. It was focused on the mechanical behavior between YSZ-glass composite seals and Fe–16Cr alloy under various thermal cycles by shear force testing and tensile force testing. The shear strength and the tensile strength between H4-20 seals and Fe–16Cr alloy were higher than that of H1-20. Two composite seals differed in characteristic temperature, viscosity, and crystalline phase with possible impacts on the joint strength. The interfacial composition between H1-20 and Fe–16Cr alloy was different from that of H4-20. Based on examination results, four possible fracture modes were proposed to illustrate the failure mechanism between composite seals and alloy.