| Seals used for solid oxide fuel cells should have low gas leak rates at elevated operating temperatures (700~900 œC). Fused glasses or glass ceramics applied to stack components such as metal interconnects have been known to provide a good hermetic seal. Metal interconnects have a specific surface roughness in the nanometer-to-micron scale, depending on the manufacturing process employed to create the surface. Therefore, the viscosity of a fused glass at seal operating temperatures is expected to affect seal performance. In this work, the seal performance of two different glasses was compared by measuring gas leak rates and glass viscosity at elevated temperatures. It was shown that for sealing a metal with a rough surface, the working viscosity of the glass seal should be properly chosen to reduce leak rates at the glass/metal interface. |
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