Chapter 39. Time Dependence of Oxidation-Induced Microstructural Changes in Nicalon- and Nextel-Reinforced SiC

  1. John B. Wachtman Jr.
  1. P. F. Tortorelli and
  2. K. L. More

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314876.ch39

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4

How to Cite

Tortorelli, P. F. and More, K. L. (1996) Time Dependence of Oxidation-Induced Microstructural Changes in Nicalon- and Nextel-Reinforced SiC, in Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314876.ch39

Author Information

  1. Metals and Ceramics Division Oak Ridge National Laboratory P. O. Box 2008 Oak Ridge, Tennessee 37831-6156

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 1996

ISBN Information

Print ISBN: 9780470375433

Online ISBN: 9780470314876

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Keywords:

  • thermogravimetric analyses;
  • electron microscopy;
  • high-temperature oxidation behavior;
  • carbon interphases;
  • no seal coating

Summary

Thermogravimetric analyses and electron microscopy were used to characterize the high-temperature oxidation behavior of Nicalon- and Nextel 312-reinforced SiC with carbon interphases and no seal coating. The results have been used to analyze the respective time dependencies of the oxidation reactions leading to carbon loss and the growth of solid products in the interfacial regions. While the overall oxidation responses of these two composite systems were qualitatively similar, the Nextel 312-reinforced SiC showed a longer period of carbon depletion and slower accumulation of oxide product in the interfacial areas. Consequently, this composite showed some resistance to brittle failure after oxidation times that completely embrittled the Nicalon/SiC. However, because of the reactions at the fiber-matrix interface, the incorporation of a more oxidation-resistant fiber in SiC with carbon interphases leads to only small improvements in high-temperature environmental stability.