Chapter 1. Comparison of Flexure Creep Behavior of Silicon Nitride Between Static and Cyclic Loading at Elevated Temperature

  1. John B. Wachtman Jr.
  1. Sung R. Choi1 and
  2. Jonathan A. Salem2

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314555.ch1

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5

How to Cite

Choi, S. R. and Salem, J. A. (1994) Comparison of Flexure Creep Behavior of Silicon Nitride Between Static and Cyclic Loading at Elevated Temperature, in Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314555.ch1

Author Information

  1. 1

    Cleveland State University, Cleveland, OH 44115

  2. 2

    NASA Lewis Research Center, Cleveland, OH 44135

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 1994

ISBN Information

Print ISBN: 9780470375334

Online ISBN: 9780470314555

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Keywords:

  • mechanical behavior;
  • creep growth;
  • crack growth;
  • monoliths;
  • hot-pressed silicon nitride

Summary

The creep behavior of a hot-pressed silicon nitride was determined in flexure at 1300° C in air using sinusoidal cyclic loading. It was found that the steady-state stress exponent (N = 1.7) under cyclic loading was lower than that (N = 3.9) obtained under static loading, indicating that cyclic loading is less creep susceptible than static loading. For a given maximum applied stress and a given frequency, the steady-state strain rate increased with increasing stress ratio (R-ratio). The frequency did not exhibit any systematic effect on creep strain rate.