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2010
Conference Paper
Titel
Sealing glasses for SOFC - degradation behaviour
Abstract
The stability of sealing glasses is one of the crit. issues concerning the long-term operation of SOFC. Different reasons are responsible for failures of the glass sealings resulting from thermal cycling, stack deformation or chem. degrdn. due to interactions with fuel gas, interconnectors or protective coatings. Different reactions with an interconnector material (Crofer 22) under oxidizing and reducing conditions lead to cryst. product layers, which affect the bonding strength and microstructure of the sealing material at the interfaces. Effects of externally applied elec. voltage on the sealing glass provide insights into mechanisms of reactions at anodically and cathodically polarized interfaces of the interconnector material. Tests of model sealings under elec. voltage in combination with a dual atm. reveal addnl. information about the stability of sealing glasses.