Chapter 25. Fracture and Flexural Characterization of Monolithic SiC and SiCw/SiC Composites at Room and Elevated Temperatures

  1. John B. Wachtman Jr.
  1. Hassan Mahfuz,
  2. Durga P. Zadoo,
  3. Freeman Wilks,
  4. Md. Maniruzzaman,
  5. Uday Vaidya and
  6. Shaik Jeelani

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314500.ch25

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - A: Ceramic Engineering and Science Proceedings, Volume 15, Issue 4

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - A: Ceramic Engineering and Science Proceedings, Volume 15, Issue 4

How to Cite

Mahfuz, H., Zadoo, D. P., Wilks, F., Maniruzzaman, Md., Vaidya, U. and Jeelani, S. (2008) Fracture and Flexural Characterization of Monolithic SiC and SiCw/SiC Composites at Room and Elevated Temperatures, in Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - A: Ceramic Engineering and Science Proceedings, Volume 15, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314500.ch25

Author Information

  1. Materials Research Laboratory Tuskegee University, Tuskegee, Alabama

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 1994

ISBN Information

Print ISBN: 9780470375327

Online ISBN: 9780470314500

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Keywords:

  • whisker/matrix;
  • configuration;
  • flexural;
  • whisker;
  • toughness

Summary

The fracture and flexural behavior of monolithic SiC and SiC–whisker reinforced SiC composites (SiCw/SiC) have been investigated at room and elevated temperatures. Flexure and fracture tests were conducted in a four-point beam configuration at 23°C, 800°C and 1200°C to study the effects of whisker reinforcements especially with respect to mechanical and thermal stability in high energy environments. Flexural strengths and fracture toughness data within the test temperature range are presented in graphical as well as in weibull form, and experimental observations are analyzed and discussed. Increase in flexural strength as well as in fracture toughness has been observed with the whisker reinforcement. However, it was found that the trend discontinues after a certain range of temperature. Post failure analysis has been performed through the Scanning Electron Microscope (SEM). Formation of a glass phase has been observed at the whisker/matrix interface and the crack growth was found to be shifting from intergranular to transgranular with the rise in temperature. Effects of whisker reinforcement and the degradation of flexural and fracture properties at elevated temperature are investigated. Ultrasonic Time of Flight(ToF) and attenuation measurements have been performed through the thickness of the untested as well as fractured specimen, and the variation in the ultrasonic ToF and attenuation are discussed in this paper.