Chapter 61. Mechanical and Thermal Properties of Dense Sic\Sic Composite Fabricated by Reaction-Bonding Process
- Mrityunjay Singh and
- Todd Jessen
Published Online: 26 MAR 2008
Copyright © 2001 The American Ceramic Society
25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3
How to Cite
Taguchi, T., Igawa, N., Yamada, R., Futakawa, M. and Jitsukawa, S. (2001) Mechanical and Thermal Properties of Dense Sic\Sic Composite Fabricated by Reaction-Bonding Process, in 25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3 (eds M. Singh and T. Jessen), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294680.ch61
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 2001
Print ISBN: 9780470375730
Online ISBN: 9780470294680
The high dense SiC\SiC composites were fabricated by a Reaction-Bonding (RB) process to achieve both a high thermal diffusivity and strength. A 2D-SiC fabric fabric was coated with double layers of Carbon and SiC by Chemical Vapor Deposition (CVD). This coated fabric and one without coating were used to evaluate the effect of the double layer coating on the mechanical and thermal properties. Furthermore, a 2D-plane weave of Hi-NICALON and a 2D-8 harness satin weave of Hi-NICALON Type-S were used to investigate the difference of fiber fabrics:. The relative density of the composite by RB process attained high levels of 90% or even higher.
Three-point bend bar specimens of 25 mm-long, 5 mm-wide and 2 mm-thick were used to evaluate mechanical properties of the composites. Fracture behavior was analyzed by examining the stress-displacement curves. The fracture surfaces were observed with a scanning electron microscope. The composites without coating showed catastrophic failure behavior, while those with the coating did not. Results indicate that the double coating is quite effective in improving the toughness of SiC\SiC fabricated by RB process. The fracture stress of the composites using Hi-NICALON Type-S fiber fabric was higher than that of the composite using Hi-NICALON fiber fabric. The reason is that the strength degradation of Hi-NICALON Type-S fibers was smaller than that of Hi-NICALON fibers at RB process conditions.
The thermal diffusivity of the composite was measured at room temperature using a laser flash thermal diffusivity analyzer. Results showed that the thermal diffusivity of SiC\SiC fabricated by RB process was much higher than that of the SiC\SiC by the conventional process.