Chapter 49. The Role of Ambient Gaseous Atmosphere in Thermal Diffusivity Transverse to the Fiber Plane

  1. John B. Wachtman Jr
  1. D. P. H. Hasselman1,
  2. A. Venkateswaran1,
  3. M. H. Yu1 and
  4. H. Tawil2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470313848.ch49

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

Hasselman, D. P. H., Venkateswaran, A., Yu, M. H. and Tawil, H. (1991) The Role of Ambient Gaseous Atmosphere in Thermal Diffusivity Transverse to the Fiber Plane, 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.ch49

Author Information

  1. 1

    Virginia Polytechnic Institute and State University Blacksburg, VA 24061

  2. 2

    Societe Propulsion Europeenne Le Cinq Chemins-Le Haillan F 33165 Saint Medard-en-Jalles France

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:

  • anisotropy;
  • atmosphere;
  • composites;
  • micrographs;
  • helium

Summary

Thermal diffusivity transverse to the fiber plane of alumina and SiC 0/90 multilayer fiber-reinforced CVD-SiC matrix composites was found to decrease when heated to 1500°C. This effect was due to the fiber debonding and matrix cracking parallel to the fiber plane, attributed to the generation of internal stresses due to thermal expansion mismatch and anisotropy for these two composites, respectively, on heating to temperatures above the manufacturing temperature. Prior to heating to 1500°C, thermal diffusivity was found to be independent of the nature of the ambient atmosphere. However, following heating to 1500°C, the thermal diffusivity in vacuum was found to be less than in nitrogen or helium, indicative of the access of the external atmosphere to the debonded interfaces and matrix cracks.