Chapter 9. Microstructural Characterization of Silicon Nitride Ceramics Processed by Pressureless Sintering, Overpressure Sintering, and Sinter HIP

  1. John B. Wachtman Jr.
  1. K. R. Selkregg1,
  2. K. L. More2,
  3. S. G. Seshadri2 and
  4. C. H. McMurty2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470313008.ch9

A Collection of Papers Presented at the 14th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 11, Issue 7/8

A Collection of Papers Presented at the 14th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 11, Issue 7/8

How to Cite

Selkregg, K. R., More, K. L., Seshadri, S. G. and McMurty, C. H. (1990) Microstructural Characterization of Silicon Nitride Ceramics Processed by Pressureless Sintering, Overpressure Sintering, and Sinter HIP, in A Collection of Papers Presented at the 14th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 11, Issue 7/8 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313008.ch9

Author Information

  1. 1

    The Carborundum Co. Niagara Falls, NY 14302

  2. 2

    Oak Ridge National Laboratory High Temperature Materials Laboratory Oak Ridge, TN 37831

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1990

ISBN Information

Print ISBN: 9780470374924

Online ISBN: 9780470313008

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Keywords:

  • atmospheric sintering;
  • electron microscopy;
  • microstructure;
  • consolidation;
  • fabrication

Summary

Silicon nitride ceramics of the same nominal sialon composition have been sintered under different conditions including atmospheric sintering, overpressure sintering, reaction-bonded (nitrided pressureless sinter), and sinter/HIP cycles. The sintered ceramics, which exhibited dramatic differences in fracture toughness, have been characterized by X-ray diffraction, scanning electron microscopy, analytical transmission electron microscopy, and image analysis techniques. Fracture toughness data have been correlated to the microstructural and chemical analysis of the grain-boundary phases. The microstructure was the strongest influencing factor on the observed fracture-toughness difference.