Interfacial properties of (Ag + CuO) brazes used as sealing materials in SOFC stacks

Rallou Chatzimichail, George Triantafyllou, Frank Tietz, Panagiotis Nikolopoulos

Research output: Contribution to journalArticlepeer-review

Abstract

Ceramic insulation layers in combination with air braze filler metals were investigated as material compositions suitable for joining the metallic components in planar solid oxide fuel cell stacks. This paper reports on a series of wetting experiments for determination of the interfacial properties of pure Ag and Ag + CuO brazes in contact with the oxides MgO, MgAl 2O4, Al2O3 and the mixture MgO + MgAl2O4, as well as with ferritic steel at 1273 K. The long-term stability of the ceramic/Ag + CuO/steel joints after exposure for longer periods of time (1000 h) at 1073 K is also assessed. The influence on joining of CuO additions in the noble metal was investigated following two different routes. The first one involved melting of Ag + 4 wt% CuO brazes on the surface of solid substrates (ceramic, steel), and the second one involved melting of pure Ag on the substrates coated with a thin CuOx layer. No differences in the values of the measured contact angles were observed. Furthermore, it was found that the reactions taking place at the interface braze/steel at the initial stage of brazing is extended in the case of Ag + 4 wt% CuO during the long-term exposure at envisaged operating temperature limiting the stability of the joint. © 2013 Springer Science+Business Media New York.
Original languageEnglish
Pages (from-to)300
Number of pages313
JournalJournal of Materials Science
Volume49
Issue number1
DOIs
Publication statusPublished - 2014

Fingerprint

Dive into the research topics of 'Interfacial properties of (Ag + CuO) brazes used as sealing materials in SOFC stacks'. Together they form a unique fingerprint.

Cite this