Chapter 31. Effect of Temperature on Tungsten Core SiC Monofilament
- John B. Wachtman Jr.
Published Online: 26 MAR 2008
Copyright © 1990 The American Ceramic Society, Inc.
14th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 11, Issue 9/10
How to Cite
Marr, S. L. and Ko, F. K. (1990) Effect of Temperature on Tungsten Core SiC Monofilament, in 14th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 11, Issue 9/10 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313053.ch31
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 1990
Print ISBN: 9780470374931
Online ISBN: 9780470313053
The thermal stability of a tungsten core SiC monofilament fiber, SIGMA™, is studied with special emphasis on the determination of the origin of fiber strength increase under specific heat-treatment conditions. Tensile strength of the SiC fiber is evaluated by room-temperature tensile test for as-received and thermally exposed fiber. Fibers subjected to thermal exposure for 1 h in air and in argon at temperatures >800°C experienced up to a 41% loss of strength. Exposure at 400° and 600°C in air, however, resulted in a 33% and 25% increase in tensile strength, respectively. Additionally, exposure at 600°C in argon resulted in a 47% increase in strength. Heat treatment at 400°-600°C appears to optimize the strength potential of this fiber.
The presence of an SiO2 film is confirmed through scanning Auger spectroscopy. It is suggested thal he presence of the silica layer formed under the heat treatment conditions of 1 h aposure in air or argon at temperatures between 400° and 600°C functions as a surface-healingfilm by blunting surface flaws. The result is enhanced fiber strength.