Chapter 55. Degradation of SiC Whiskers at Elevated Temperatures
- John B. Wachtman Jr.
Published Online: 26 MAR 2008
Copyright © 1989 The American Ceramic Society, Inc.
A Collection of Papers Presented at the 13th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 10, Issue 7/8
How to Cite
Whitehead, A. J., Page, T. F. and Hlggins, I. (1989) Degradation of SiC Whiskers at Elevated Temperatures, in A Collection of Papers Presented at the 13th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 10, Issue 7/8 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470310557.ch55
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 1989
Print ISBN: 9780470374863
Online ISBN: 9780470310557
- x-ray powder diffraction;
- chemical vapor infiltration;
- silicon carbide;
- scanning electron microscopy
Detrimental changes to the morphology, microstructure, and chemistry of silicon carbide whisker materials can occur during the fabrication of ceramic matrix composites. To explore the possible effects of heat treatment on both whisker morphology and pofytype, β-SiC whiskers have been examined after exposure to elevated temperatures (1850°–2150°C) for varying times in controlled atmospheres. Morphological changes have been followed by SEM and transformation in poly type by using XRD and TEM. It has been found that changes in shape occur extremely rapidly above 200VC, but that pofytype transformations (from β to a) appear to be much slower. Suggestions are made as to the mechanism by which the morphological changes occur and how these are related to the changes in pofytype. The implications for composite fabrication are discussed in terms of a thermal stability envelope inside which little change in whisker morphology is expected to occur during processing.