Chapter 18. Long Term Tensile Creep Behavior of Highly Heat-Resistant Silicon Nitride for Ceramic Gas Turbines

  1. Mrityunjay Singh and
  2. Todd Jessen
  1. Tatsuki Ohji

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294680.ch18

25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3

25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3

How to Cite

Ohji, T. (2001) Long Term Tensile Creep Behavior of Highly Heat-Resistant Silicon Nitride for Ceramic Gas Turbines, in 25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3 (eds M. Singh and T. Jessen), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294680.ch18

Author Information

  1. National Industrial Research Institute of Nagoya Nagoya 463–8687, Japan

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2001

ISBN Information

Print ISBN: 9780470375730

Online ISBN: 9780470294680

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Keywords:

  • ceramic;
  • components;
  • oxidation;
  • microscopy;
  • X-ray

Summary

In these decades, silicon nitride has been recognized as the most promising material for ceramic gas-turbine components. In this paper, creep and creep rupture behavior of silicon nitride, which has been developed for such applications by controlling the grain boundary phase and microstructure, are investigated at 1350°C - 1450°C in air. For this purpose, tensile creep tests have been conducted up to 10,000 hours. Even in such a high temperature range, this silicon nitride showed very excellent creep resistance. Most of the creep curves tended to exhibit transient creep behavior, and in some conditions, creep rupture was not observed until 10,000 hours. The obtained creep rate exponents were very high, ranging from 7 to 9. The creep lives were discussed in relation with cavity formation. The excellent creep resistance was attributed to secondary crystal formation of Lu2Si2O7 at the grain boundaries and triple junctions.