Torsional shear strength behavior of advanced glass-ceramic sealants for SOFC/SOEC applications

Since reliable long term operation of SOFC and SOEC devices depends critically on the mechanical behavior of the sealant material, the current work focuses on the characterization of the shear strength by a torsion test of two different glass-ceramic sealants that are used to join Crofer22APU substrates in an application relevant configuration. The two glass-ceramic sealants differ in terms of characteristic temperatures and crystalline phases with possible impications on the joining behavior. Statistically identical shear stress values were measured at room temperature for joined hourglasses of different size with both sealants, thus confirming a size independence of the measured strength values. Experimental post-test examination results confirm that the interfaces play a strong role regarding the measured shear strength and provide important insights with respect to integration of metallic and glass-ceramic components in SOFC/SOEC stacks.