Chapter 21. Molybdenum-Palladium Fiber-Matrix Interlayers for Ceramic Composites

  1. John B. Wachtman Jr.
  1. R. S. Hay1,
  2. T. Mah2 and
  3. C. Cooke2

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314555.ch21

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

Hay, R. S., Mah, T. and Cooke, C. (1994) Molybdenum-Palladium Fiber-Matrix Interlayers for Ceramic 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.ch21

Author Information

  1. 1

    Wright Laboratory, Materials Directorate WPAFB, OH 45433

  2. 2

    Universal Energy Systems Dayton, OH 45433

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:

  • palladium ligament interfaces;
  • tough ceramic fiber-matrix composites;
  • crack deflection;
  • fiber pullout;
  • carbon and boron nitride interlayers

Summary

Previous work to form palladium ligament interfaces between single crystal alumina fibers and yttrium-aluminum garnet (YAG) matrices was continued. Alumina fibers were coated with Pd and Mo by magnetron sputtering and by use of Pd, Mo chloride, PdNO3, and MoO3-ammonia solutions. The fibers were hot-pressed in YAG powder. The composites were characterized with optical microscopy, SEM, and TEM. Bend bar fracture surfaces were examined for fiber pullout. Initial work using molybdenum as a fugitive phase for the pore space between ligaments was encouraging; crack deflection and fiber pullout were observed in composites with porous Pd fiber-matrix interlayers. More recent efforts to produce composites with thicker, more uniform fiber coatings and higher fiber volume fractions suggests that the palladium ligament interface concept may be viable, but that molybdenum is unsuitable for use as a fugitive phase in the alumina-YAG system because molybdenum oxides react or form eutectics with alumina and YAG.