Chapter 10. Indentation Residual Stresses in Rbsn and Rbsn Composites

  1. John B. Wachtman Jr.
  1. S. V. Nair,
  2. Peter Z. Q. Cai and
  3. J. E. Ritter

Published Online: 26 MAR 2008

DOI: 10.1002/9780470313954.ch10

Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 7/8

Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 7/8

How to Cite

Nair, S. V., Cai, P. Z. Q. and Ritter, J. E. (1994) Indentation Residual Stresses in Rbsn and Rbsn Composites, in Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 7/8 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313954.ch10

Author Information

  1. Mechanical Engineering Department, University of Massachusetts, Amherst, MA 01003 A. Lightfoot, and J.S. Haggerty, Materials Processing Center, Massachusetts Institute of Technology, Cambridge, MA 02139

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1994

ISBN Information

Print ISBN: 9780470375174

Online ISBN: 9780470313954

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Keywords:

  • ceramics;
  • mechanical;
  • parameter;
  • microscopy;
  • fractography

Summary

The evaluation of toughness of brittle materials by indentation methods is based on the premise that significant residual stresses are present beneath the indenter. In porous materials, there is the possibility that residual stresses may not develop because of pore collapse, or densification, beneath the indenter. The presence of residual stresses was critically assessed using post-indentation strength measurements in a nanoporous reaction bonded silicon nitride (RBSN) and RBSN reinforced with SiC particulates which contain porosity levels on the order of 25%. The results showed the presence of significant residual stresses in these materials and the applicability of the indentation-strength method to toughness determination of the nanoporous materials was demonstrated. However, the indentation crack length method of toughness determination was unable to reveal variations in toughness between the different samples.