Chapter 8. Viscous Slip at Grain Boundaries in Highly Covalent Ceramics

  1. J. P. Singh
  1. G. Pezzotti1,
  2. K. Maruyama1,
  3. K. Ota2,
  4. H.-J. Kleebe3 and
  5. T. Nishida1

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294444.ch8

Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 18, Issue 4

Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 18, Issue 4

How to Cite

Pezzotti, G., Maruyama, K., Ota, K., Kleebe, H.-J. and Nishida, T. (1997) Viscous Slip at Grain Boundaries in Highly Covalent Ceramics, in Proceedings of the 21st Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 18, Issue 4 (ed J. P. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294444.ch8

Author Information

  1. 1

    Department of Materials, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, 606 Kyoto, Japan

  2. 2

    The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibarakishi, Osaka 567, Japan

  3. 3

    Institut fur Materialforschung, Universitat Bayreuth, Ludwig-Thoma Strasse 36B, D-95440 Bayreuth, Germany

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1997

ISBN Information

Print ISBN: 9780470375532

Online ISBN: 9780470294444

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Keywords:

  • viscosity;
  • systematically;
  • variation;
  • disappeared;
  • intragranular dislocation activity

Summary

Systematic experimentation on grain-boundary sliding of ceramics with a glassy film at grain boundaries has been carried out by low-frequency internal friction technique up to ≈2000°C. The microstructure of the model Si3N4 polycrystal selected for this basic investigation consisted of equiaxed grains continuously encompassed by a nanometer-sized film of SiO2 glass. The SiO2 film was doped with increasing amounts of two different glass-network modifier anions (i.e., F and Cl) in order to systematically lower its bulk viscosity. For comparison, a dilute sialon material was also tested in which the grain-boundary film collapsed and the grains were directly bonded. An internal-friction peak, with a top temperature displayed just below the melting point of the grain-boundary glass, was systematically found. The peak shifted upon frequency variation or dopant addition being closely related to the viscosity change of bulk SiO2 glass. In the dilute sialon material, due to the collapse of grain-boundary film, the anelastic peak of internal friction disappeared and only a viscoelastic background rising was detected.