Chapter 19. Synthesis, Characterization and Tensile Strength of C V I C/SiC, SiC/SiC, SiC/B4C and C/B4C Composites
- John B. Wachtman Jr.
Published Online: 26 MAR 2008
Copyright © 1992 The American Ceramics Society
Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 9/10
How to Cite
Kmetz, M. A., Laliberte, J. M., Sub, S. L. and Galasso, F. S. (1994) Synthesis, Characterization and Tensile Strength of C V I C/SiC, SiC/SiC, SiC/B4C and C/B4C Composites, in Proceedings of the 16th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2: Ceramic Engineering and Science Proceedings, Volume 13, Issue 9/10 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313978.ch19
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 1994
Print ISBN: 9780470375198
Online ISBN: 9780470313978
Single strand unidirectional composites were fabricated by chemical vapor infiltration of SiC or B4C matrices into Nicalon and T-300 carbon yarn. Two different precursors for the deposition of CVD carbon were investigated. Tensile strength measurements of yarns coated with carbon produced by the pyrolysis of propylene gave higher strengths than those coated with carbon formed from the pyrolysis of methane. In addition, a new CVD boron-carbon interface was also developed. Coating of this material was found not to degrade Nicalon* or T-300 carbon yarn.** Composites fabricated with this interface had high strengths (around 45 ksi for SiC/SiC composites and 75 ksi for C/SiC composites). In the C/SiC system, annealing studies performed in air at 1100°C for 50 hrs showed that the composites utilizing a carbon interface were completely degraded whereas the C/SiC composites utilizing a B-C interface showed only a 30% reduction in strength. In addition, this same annealing treatment was found to have no effect on the strength of the SiC/B-C/SiC composites. In the SiC/B4C and C/B4C systems B-C was also found to be the best interface. The coated fibers and composites were characterized by SEM and X-ray diffraction analysis.