Chapter 31. Mechanical Behaviour of Glassy Composite Seals for IT-SOFC Application.
- Narottam P. Bansal,
- Andrew Wereszczak and
- Edgar Lara-Curzio
Published Online: 26 MAR 2008
Copyright © 2007 The American Ceramics Society
Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4
How to Cite
Nielsen, K. A., Solvang, M., Nielsen, S. B. L. and Beeaff, D. (2006) Mechanical Behaviour of Glassy Composite Seals for IT-SOFC Application., in Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, Volume 27, Issue 4 (eds N. P. Bansal, A. Wereszczak and E. Lara-Curzio), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291337.ch31
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 2006
Print ISBN: 9780470080542
Online ISBN: 9780470291337
Glass-based sealants have been developed with emphasis on filler material and surface treatment of the sealing components in order to optimise their mechanical and functional behaviour during the initial sealing process as well as during thermal cycling of the SOFC-stack after exposure to operating conditions. The bonding strength and microstructure of the interfaces between composite seals and interconnect materials were investigated as a function of surface treatment of the sealing surfaces, glass matrix composition, sealing pressure and temperature. The initial sealing performance and resistance to thermal cycling were then investigated on selected combinations of materials after ageing.
Strongest bonding between sodium aluminosilicate glass composite and steel surfaces was obtained for sealing at 850°C. For the strongest interface, having shear strength of 2.35 MPa, rupture occurred in the glass matrix, meaning that the glass-steel interfaces are, in this case, even stronger. Application of transition metal oxide coatings on etched surfaces of Crofer 22APU steel showed a significant improvement in the development of a seamless transition zone between metal and glass, whereas the same coatings on a sanded surface showed no influence on the bonding strength, which on the other hand were all recorded at a fairly high level, only 15-20% less than the 2.35 MPa seen for the glass. Ageing and thermal cycling of sealed samples did not deteriorate the recorded strength.