Joint strength of a solid oxide fuel cell glass–ceramic sealant with metallic interconnect

The aim of this study is to investigate the joint strength between a newly developed glass–ceramic sealant (GC-9) and metallic interconnect (Crofer 22 H) for planar solid oxide fuel cells (pSOFCs). The joint strength is evaluated at room temperature and 800 °C under shear and tensile loading using two types of sandwich specimen. Effects of number of initial sealant-spreading side, pre-oxidation of metallic interconnect, and thermal aging in air on the joint strength are studied. Regardless of testing temperature and loading mode, the joint strength of specimens initially with two sides of glass–ceramic sealant is greater than that of single-sided ones. A pre-oxidation treatment of the metal coupon at 900 °C for 2 h or 20 h does not generate a beneficial effect on the shear and tensile joint strength for all the given testing conditions. Compared to the shear strength of unaged joint specimens, a reduction of 17–19% in shear joint strength at 800 °C is observed for variously aged ones.

► A technique is developed to measure strength of glass/metal interconnect joint.
► Two-side-sealant joints have a greater joint strength than single-side ones.
► A pre-oxidation treatment of metal interconnect does not enhance joint strength.
► A thermal aging treatment in air degrades the joint strength.
► Glass/chromate interface is the weakest layer to resist mechanical loading.