Chapter 9. Engineering Property Limitations of Structural Ceramics and Ceramic Composites Above 1600°C

  1. John B. Wachtman Jr
  1. E. L. Courtright

Published Online: 26 MAR 2008

DOI: 10.1002/9780470313848.ch9

Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 9/10

Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 9/10

How to Cite

Courtright, E. L. (1991) Engineering Property Limitations of Structural Ceramics and Ceramic Composites Above 1600°C, in Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 9/10 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313848.ch9

Author Information

  1. Pacific Northwest Laboratory, P.O. Box 999 Richland, WA 99352

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1991

ISBN Information

Print ISBN: 9780470375105

Online ISBN: 9780470313848

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Keywords:

  • mechanisms;
  • thermodynamic;
  • monolithic;
  • gravimetric;
  • homogeneous

Summary

Current high-temperature performance limitations for structural ceramics associated with design-related requirements, e.g. creep, fracture toughness, fatigue, and oxidation resistance, are reviewed. Nonoxide ceramics exhibit good strength at low temperatures, but do not retain their strength at high temperatures and generally do not have adequate oxidative stability. While many oxides are thermochemically stable at high temperatures in oxidizing atmospheres, the rate of oxygen permeation is very high and this leads to interface degradation when nonoxide fibers are used as reinforcements. Most oxides also exhibit poor high-temperature strength and creep resistance, but recent research suggests that acceptable levels of creep resistance may be achievable in single crystals. While toughness in a ceramic matrix composite is generally thought to be a function of interface sliding between fiber and matrix coupled with other crack deflection processes, adequate matrix toughness is also required. Cyclic fatigue resistance is another performance-limiting concern in ceramic matrix composites. More data are needed to achieve a better understanding of operative mechanisms.