Fiber Wetting and Coatings for Composite Fabrication
Abstract
Graphite fibers resist wetting when immersed in most molten metals. They must be coated with a material that can be wet and that also protects the fibers against chemical degradation during processing. A model of the graphite fiber surface is proposed, and a brief history of coatings that have been investigated for wetting is presented. The titanium-boron chemical vapor deposition process is discussed as well as the graphite-metal interface that results from that process. Finally, Aerospace-developed air-stable coatings and their processing are described. The technique used by Aerospace is a solution- coating process. The fibers are passed through appropriate organometallic solutions followed by either hydrolysis or pyrolysis of the organometallic compounds to form the desired coating on the fiber surfaces. Fibers have been coated with selected oxides, nitrides, and carbides, using this technique. Also, a modification of this technique can be used to coat fibers with amorphous carbon. These coatings can be applied to other fibers as well as graphite, and some are easily wet by metals. In addition, the coatings are expected to be useful for controlling the fiber matrix bond strength in ceramic matrix composites.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1986
- Accession Number
- ADA175154
Entities
People
- Howard Katzman
Organizations
- The Aerospace Corporation