Chapter 13. Development of BN/SiC Duplex Fiber Coatings for Fiber-Reinforced Alumina Matrix Composites Fabricated by Directed Metal Oxidation
- John B. Wachtman Jr.
Published Online: 26 MAR 2008
Copyright © 1993 The American Ceramic Society
Proceedings of the 17th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 14, Issue 9/10
How to Cite
Fareed, A. S., Schiroky, G. H. and Kennedy, C. R. (1993) Development of BN/SiC Duplex Fiber Coatings for Fiber-Reinforced Alumina Matrix Composites Fabricated by Directed Metal Oxidation, in Proceedings of the 17th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 14, Issue 9/10 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314234.ch13
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 1993
Print ISBN: 9780470375273
Online ISBN: 9780470314234
- flexural strengths;
Fiber-reinforced alumina matrix composites have been developed using directed metal oxidation as the fabrication route. High toughness and strength can only be realized when appropriate coatings are applied to the fibers. These coatings must: protect fibers from reacting with molten aluminum alloy during alumina matrix growth; protect fibers from oxidation at matrix growth temperatures of about 1000°C; and provide for fiber/matrix debonding and fiber pull-out. Using chemical vapor infiltration as the approach, a BN/SiC duplex coating system has been developed which fulfills these requirements. Properties of fiber-reinforced composites are discussed along with the influence of fiber coating parameters on composite properties. With optimized coatings, NicalonTM/alumina composites show 1200°C flexural strengths of 488 MPa and excellent tensile fatigue behavior (>2 million cycles from 8 to 83 MPa at 1000°C in air) and thermal shock resistance.