Chapter 10. Super-Tough Silicon Nitride with R-Curve Behavior

  1. John B. Wachtman Jr.
  1. Chien-Wei Li and
  2. John Yamanis

Published Online: 26 MAR 2008

DOI: 10.1002/9780470310557.ch10

A Collection of Papers Presented at the 13th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 10, Issue 7/8

A Collection of Papers Presented at the 13th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 10, Issue 7/8

How to Cite

Li, C.-W. and Yamanis, J. (1989) Super-Tough Silicon Nitride with R-Curve Behavior, in A Collection of Papers Presented at the 13th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 10, Issue 7/8 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470310557.ch10

Author Information

  1. Allied-Signal, Inc. Morristown, NJ 07960

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1989

ISBN Information

Print ISBN: 9780470374863

Online ISBN: 9780470310557

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Keywords:

  • chemical vapor infiltration;
  • whiskers;
  • silicon nitride ceramics;
  • fracture toughness;
  • crack growth resistance

Summary

Silicon nitride with a fracture toughness of 10.6 ± 0.5 MPa · m1/2 has been developed. This tough, nontransforming ceramic exhibits pronounced R-curve behavior. Double cantilever beam (DCB) and indentation/strength measurements were used to characterize the R-curve, and good agreement between the two methods was obtained. The high toughness and R-curve behavior of this silicon nitride material is attributed to extensive crack deflection and crack bridging phenomena arising from its unique microstructure. As a result of R-curve behavior, the material exhibits flaw tolerance and is, therefore, characterized by a high Weibull modulus. Furthermore, this ceramic is more damage tolerant than silicon nitrides with flat crack growth resistance.