Chapter 25. Sol-Gel Coating of Nicalon™ Fiber Cloths

  1. John B. Wachtman Jr.
  1. Michael K. Cinibulk

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314876.ch25

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4

How to Cite

Cinibulk, M. K. (1996) Sol-Gel Coating of Nicalon™ Fiber Cloths, in Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314876.ch25

Author Information

  1. Wright Laboratory, Materials Directorate (UES, Inc.) Wright-Patterson Air Force Base, OH 45433-7817

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 1996

ISBN Information

Print ISBN: 9780470375433

Online ISBN: 9780470314876

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Keywords:

  • multifilament tows;
  • electrostatic coating;
  • surface charge;
  • heterocoagulation;
  • polyelectrolyte

Summary

Successful coating of multifilament tows and cloths requires complete and uniform coverage of fibers without bridging the fibers and tows by the coating. Two methods were investigated for coating Nicalon™ cloths with oxides. The first, dip coating, relies strictly on the wetting of the fibers by the oxide sol, while the second, electrostatic coating, relies on the control of surface charge to encourage heterocoagulation of the particles on the fiber surfaces. Cloths were treated with a polyelectrolyte (ammonium polymethacrylate) to impart a negative charge to the fiber surfaces. Cloths were coated with boehmite sols, alumina suspensions, mullite sols, or mullite suspensions. Water or octanol was used to displace excess coating liquid. Dip coating was not successful in uniformly coating Nicalon cloths, while electrostatic coating was found to be a promising technique for obtaining uniform coverage with minimal bridging.