Chapter 38. Hybrid Microwave-Assisted Chemical Vapor Infiltration of Alumina Fiber Composites

  1. John B. Wachtman Jr.
  1. Daniel J. Skamser,
  2. Paul S. Day,
  3. Hamlin M. Jennings and
  4. D. Lynn Johnson

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314555.ch38

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5

How to Cite

Skamser, D. J., Day, P. S., Jennings, H. M. and Johnson, D. L. (1994) Hybrid Microwave-Assisted Chemical Vapor Infiltration of Alumina Fiber Composites, in Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314555.ch38

Author Information

  1. Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208–32108 Mark S. Spotz, Illinois Superconductor Corp., Evanston, IL 60201

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 1994

ISBN Information

Print ISBN: 9780470375334

Online ISBN: 9780470314555

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Keywords:

  • microwave heating configuration;
  • single mode cavity;
  • thermal runway;
  • temperature gradient;
  • chemical vapour infiltration

Summary

A novel microwave heating configuration, consisting of an alumina fiber preform surrounded by a sleeve of Sr-doped lanthanum chromite, was used to heat the center of preforms to 1100°C in a single mode cavity. The sleeve of electrically lossy material increases the critical temperature at which thermal runaway occurs inside microwave heated alumina fibers while still allowing temperature gradients to exist inside the preforms. A statistical design approach was used to conduct microwave-assisted chemical vapor infiltration (MCVI) experiments using a forced-flow configuration. ANOVA results show that low utilization of reactants, low temperatures, high flow rates, and high dilution of reactants lead to high density alumina fiber/ alumina matrix composites.