Hostname: page-component-7c8c6479df-5xszh Total loading time: 0 Render date: 2024-03-29T13:28:02.642Z Has data issue: false hasContentIssue false

Ceramic Fiber Coating by a Non-Aqueous Sol-Gel Process

Published online by Cambridge University Press:  28 February 2011

F. C. Montgomery
Affiliation:
General Atomics, San Diego, CA
H. H. Streckert
Affiliation:
General Atomics, San Diego, CA
R. O. Harrington
Affiliation:
General Atomics, San Diego, CA
J. L. Kaae
Affiliation:
General Atomics, San Diego, CA
S. P. Paguio
Affiliation:
General Atomics, San Diego, CA
D. R. Wall
Affiliation:
General Atomics, San Diego, CA
Get access

Abstract

Thin coatings of Al2O3, and Y2O3, have been prepared on desized Nicalon yarn. The layers were deposited by dip coating in homogeneous, alcohol solutions of partially hydrolyzed metal alkoxides. The coating thicknesses could be controlled by multiple dipping.

The uniformity of the coatings was affected by the alkoxide concentration. Solutions containing greater than 1 wt % equivalent oxide resulted in oxide bridging the void between the fibers.

Transmission Electron Microscopy (TEM) studies on alumina coatings formed by dip coating 300 mesh nickel grids, have shown that either eta or gamma alumina is formed after heating at temperatures as low as 700 °C. The rate of grain growth increases as the temperature increases. In addition, increased grain growth is observed for films produced from solutions with higher water:metal ratios.

The strength of coated fibers heat treated in air after coating has been determined. Alumina, and yttria coatings reduce the strength of the fiber after heating at temperatures above 900 °C. Scanning Auger analysis suggests that the coating is reacting with the fiber at these high temperatures.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Partlow, D. P. and Yoldas, B. E., Journal of Non-Crystalline Solids, 46, 153161 (1981).Google Scholar
2. Yoldas, B. E., American Ceramic Society, Bulletin, 54 289290 (1975).Google Scholar
3. Yoldas, B. E., Journal of Non-Crystalline Solids, 63, 145154 (1984).Google Scholar
4. Mazdiyasni, K. S., Lynch, C. T. and Smith, J. S., Inorg. Chem., 5, 342 (1966).Google Scholar
5. Powder Diffraction File, edited by McClune, W. F. (International Centre for Diffraction Data, Swarthmore, Pa).Google Scholar
6. Brennan, J. J. in CERAMIC MICROSTRUCTURES ′86, eds. Pask, and Evans, (Plenum Publishing Corp., 1988), pp.387389.Google Scholar