Chapter 59. Correlation Between Microstructure and Mechanical Properties in Silicon Nitride Ceramics

  1. J. P. Singh
  1. Hiroshi Hohjo1,
  2. Nobuo Kamiya1 and
  3. Takashi Miyata2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294444.ch59

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

Hohjo, H., Kamiya, N. and Miyata, T. (1997) Correlation Between Microstructure and Mechanical Properties in Silicon Nitride 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.ch59

Author Information

  1. 1

    Toyota Central R & DLabs., Inc., Nagakute, Aichi, 480-11, Japan

  2. 2

    Dept. Mat. Sci. & Eng., Nagoya University, Chikusa-ku, Nagoya-shi, 464-01, Japan

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:

  • characterized;
  • microstructural;
  • geometric constituents;
  • microstructural parameters;
  • cyclic fatigue endurance

Summary

Microstructures of several silicon nitride ceramics, which varied from nano to micron order, were characterized by means of various geometric constituents of silicon nitride grains on etched surfaces. Correlations between microstructural parameters consisting of various combinations of geometric constituents and mechanical properties (bending strength, fracture toughness and cyclic fatigue crack propagation parameter) were estimated by multiple regression analysis.

The multiple regression analysis showed the following results. The micro-structural parameters which correlated to fracture toughness with high correlative coefficient were distributions of grain size and fraction of rod-like grains described by cross-sectional area. For bending strength, highly correlative microstructural parameters were distributions of grain size and fraction of rodlike grains described by number. And for cyclic fatigue crack propagation parameter, highly correlative microstructural parameters were distributions of grain size described by number, and fraction of rod-like grains described by cross-sectional area. Consequently, the microstructure of uniform grain size and a larger number of rod-like grains may be effective for improving fracture toughness and bending strength simultaneously in silicon nitride ceramics. However, these guiding principles of microstructure design were not successful for simultaneous improvement of cyclic fatigue endurance.