Chapter 21. Fabrication of Ceramic-Ceramic Composites by Chemical Vapor Deposition

  1. William Smothers
  1. D. P. Stinton,
  2. W. J. Lackey,
  3. R. J. Lauf and
  4. T. M. Besmann

Published Online: 26 MAR 2008

DOI: 10.1002/9780470320228.ch21

Proceedings of the 8th Annual Conference on Composites and Advanced Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 5, 7/8

Proceedings of the 8th Annual Conference on Composites and Advanced Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 5, 7/8

How to Cite

Stinton, D. P., Lackey, W. J., Lauf, R. J. and Besmann, T. M. (1984) Fabrication of Ceramic-Ceramic Composites by Chemical Vapor Deposition, in Proceedings of the 8th Annual Conference on Composites and Advanced Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 5, 7/8 (ed W. Smothers), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470320228.ch21

Author Information

  1. Oak Ridge National Laboratory Oak Ridge, TN 37831

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1984

ISBN Information

Print ISBN: 9780470374139

Online ISBN: 9780470320228

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Keywords:

  • toughened ceramic composites;
  • chemical vapor deposition;
  • furnace;
  • oxidation resistant coating;
  • hydrogen

Summary

Toughened ceramic composites were produced by the simultaneous chemical vapor deposition of two phases. Fracture toughness values were nearly double the value of SiC when CH3SiCl3 and TiCl4 vapors were used to produce SiC-TiSi2 composites. Other systems consisting of SiC and the metal or metal carbides of Ni, Cr, W, and Mo were examined. Equilibrium thermodynamic analyses of these systems were performed as a function of the chemical vapor deposition variables: temperature, total pressure, and reactant concentration. These calculations confirmed that the volatile species used early in this work (organometallic compounds of Ni and Cr and the fluorides of W and Mo) were not suitable for the production of toughened composites. Additional work is under way to produce composites from the oxy- chlorides or carbonyls of Ni and Cr or the chlorides or oxychlorides of W and Mo. Thermodynamic calculations also indicated that SiC and TiC should be codeposited when CH3SiCl3, TiCl4, and a hydrocarbon are used as the coating gases. Much additional work remains to produce SiC-TiC composites and to control the morphology of the TiSi, dispersed phase so that optimum fracture toughness values can be obtained.