Chapter 46. Elevated Temperature Mechanical Properties of Sic-Ain Particulate Composites
- 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
Mariano, S. A., Friel, D. and Bar-On, I. (1993) Elevated Temperature Mechanical Properties of Sic-Ain Particulate Composites, 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.ch46
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 1993
Print ISBN: 9780470375273
Online ISBN: 9780470314234
The elevated temperature flexure strength and fracture toughness were determined for three different SiC-AIN particulate composites. SiC-AIN weight ratios of 90–10, 45–55, and 15–85 were investigated. The composites were fabricated by mechanical mixing of the SiC and A1N powders, and hot pressing below 1900°C. This was done in an attempt to achieve full density and theoretically minimize solid solution formation. The temperature regime for flexure and fracture toughness testing was 600°C to 1200°C, identified through preliminary Stepped Temperature Stress Rupture (STSR) testing. Flexure strength was determined by four point bend and fracture toughness using an ambient temperature precracked SEPB specimen loaded to failure at elevated temperature. Results indicate that both strength and toughness are temperature and composition dependent. Fracture toughness improvements exhibited in the 45% SiC-55% A1N composite at ambient temperatures were less at elevated temperature and the strength of all the composite compositions exhibited some degradation. Specifically the 45% SiC-55% AlN toughness decreased to the level of the monoliths at temperatures exceeding 800°C. This diminished toughening effect contributes to the elevated temperature strength degradation but alternative mechanisms such as oxidation could be playing a more significant role at higher temperatures.