Chapter 44. Thermodynamic Analysis of CVD Mullite Coatings

  1. John B. Wachtman Jr
  1. Rao Mulpuri and
  2. Vinod K. Sarin

Published Online: 26 MAR 2008

DOI: 10.1002/9780470314715.ch44

Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4

Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4

How to Cite

Mulpuri, R. and Sarin, V. K. (1995) Thermodynamic Analysis of CVD Mullite Coatings, in Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314715.ch44

Author Information

  1. Department of Manufacturing Engineering Boston University, Boston, MA

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1995

ISBN Information

Print ISBN: 9780470375372

Online ISBN: 9780470314715

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Keywords:

  • oxidation/corrosion;
  • ceramics;
  • corrosive;
  • controversy;
  • mullite

Summary

Mullite (3Al2O3 2SiO2) has excellent high temperature and oxidation/corrosion resistance properties. It is therefore a leading candidate coating material for high temperature structural applications. Two techniques to grow CVD mullite coatings on SiC and Si3N4 substrates were investigated. Based on equilibrium thermodynamic calculations, binary and ternary CVD phase diagrams for the AlCl3-SiCl4-CO2-H2 system were constructed. These phase diagrams showed that the formation of mullite is quite sensitive to changes in the process parameters. The effect of input stoichiometry, temperature, and pressure on deposit compositions and mullite deposition efficiency is studied.