34. Creep Deformation of NI/YSZ Cermet in SOFCS

  1. Narottam P. Bansal
  1. Wenning Liu and
  2. Jianmin Qu

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291245.ch34

Advances in Solid Oxide Fuel Cells: Ceramic Engineering and Science Proceedings, Volume 26, Number 4

Advances in Solid Oxide Fuel Cells: Ceramic Engineering and Science Proceedings, Volume 26, Number 4

How to Cite

Liu, W. and Qu, J. (2005) Creep Deformation of NI/YSZ Cermet in SOFCS, in Advances in Solid Oxide Fuel Cells: Ceramic Engineering and Science Proceedings, Volume 26, Number 4 (ed N. P. Bansal), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291245.ch34

Author Information

  1. Georgia Institute of Technology School of Mechnical Engineering Atlanta, GA, 30332-0405

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982343

Online ISBN: 9780470291245

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Keywords:

  • melting temperature;
  • visco-elastic solution;
  • ni matrix;
  • microstructure;
  • finite element method

Summary

Creep deformation becomes relevant for a material when the operating temperature is near or even lower than half of the melting temperature (in degrees of Kelvin) of that material. For most of the SOFCs under development, creep deformation of the Ni/YSZ anode is significant and must be considered. The Ni/YSZ anode is a mixture of Ni and YSZ, or a cermet. Due to the reduction of NiO, the Ni/YSZ anode also contains a large number of voids, making it a porous cermet. In this complicated microstructure, creep deformation occurs predominately in the Ni phase. However, the creep behavior of the anode is different from that of bulk Ni, due to the presence of YSZ particles and voids. It will be crucial to develop constitutive models for the Ni/YSZ anode in order to develop predictive tools for failure analysis. In this paper, a micromechanics based constitutive model is developed for the Ni/YSZ cermet. The model takes into account the microstructure of the porous cermet, and is able to describe the creep behavior very well.