Chapter 43. In-Situ Observation of Stable Crack Propagation in Toughened Silicon Nitride Ceramics

  1. Ersan Ustundag and
  2. Gary Fischman
  1. Yorinobu Takigawa,
  2. Kyoji Hiramatsu and
  3. Hiroshi Kawamoto

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294567.ch43

23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3

23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3

How to Cite

Takigawa, Y., Hiramatsu, K. and Kawamoto, H. (1999) In-Situ Observation of Stable Crack Propagation in Toughened Silicon Nitride Ceramics, in 23rd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures : A: Ceramic Engineering and Science Proceedings, Volume 20, Issue 3 (eds E. Ustundag and G. Fischman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294567.ch43

Author Information

  1. Japan Fine Ceramics Center 2–4-1 Mutsuno, Atsuta-ku Nagoya 456–8587, Japan

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1999

ISBN Information

Print ISBN: 9780470375631

Online ISBN: 9780470294567

SEARCH

Keywords:

  • propagation;
  • microstructural;
  • interface;
  • deflecting;
  • ceramics

Summary

In-situ observation of stable crack propagation is conducted in a highly anisotropic silicon nitride ceramics. Stable fracture occurs successfully by single edge-notched beam (SENB) method with crack stabilizers. However, the crack deflects about 60° from the direction of notch plane in this material. Microstructural analysis reveals that the crack propagates stepwise along interface. Since the tangent of the deflection angle corresponds to the average aspect ratio of grains on the surface plane, the highly anisotropic configuration and the weak interface must be the origin of the crack deflection. Estimating apparent fracture resistance for crack extension component in the direction parallel to the notch depth, the rising R-curve behavior is observed. Stepwise deflecting crack must play a role similar to grain bridging.