Creep rupture of the joint of a solid oxide fuel cell glassaceramic sealant with metallic interconnect

• Published in: Journal of power sources 2014-01, Vol.245, p.787-795
• Main Authors: Lin, Chih-Kuang, Lin, Kun-Liang, Yeh, Jing-Hong, Wu, Si-Han, Lee, Ruey-Yi
• Format: Article
• Language: English
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2013.07.047

Creep properties of sandwich joint specimens made of a newly developed BaOaB2O3aAl2O3aSiO2 glassaceramic sealant (GC-9) and a ferritic-stainless-steel interconnect (Crofer 22 H) for planar solid oxide fuel cells (pSOFCs) are investigated at 800 degree C under constant shear and tensile loadings. The creep rupture time of Crofer 22 H/GC-9/Crofer 22 H joint specimens is increased with a decrease in applied load for both shear and tensile loading modes. The given metal/sealant/metal joint has a greater degradation of joint strength at 800 degree C under prolonged, constant tensile loading as compared to shear loading. The tensile creep strength at a rupture time of 1000 h is about 9% of the average tensile joint strength, while the shear creep strength at 1000 h is about 23% of the average shear joint strength. Failure patterns of both shear and tensile joint specimens are similar regardless of the creep rupture time. In general, creep cracks initiate at the interface between the (Cr,Mn)3O4 spinel layer and the BaCrO4 chromate layer, penetrate through the BaCrO4 layer, and propagate along the interface between the chromate layer and glassaceramic substrate until final fracture. Final, fast fracture occasionally takes place within the glassaceramic layer.