Chapter 67. Microstructural Characterization of Composites via Electrical Measurements

  1. John B. Wachtman Jr.
  1. R. Gerhardt

Published Online: 28 MAR 2008

DOI: 10.1002/9780470314555.ch67

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5

Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5

How to Cite

Gerhardt, R. (1994) Microstructural Characterization of Composites via Electrical Measurements, in Proceedings of the 18th Annual Conference on Composites and Advanced Ceramic Materials - B: Ceramic Engineering and Science Proceedings, Volume 15, Issue 5 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314555.ch67

Author Information

  1. Georgia Institute of Technology School of Materials Science and Engineering Atlanta, GA 30332–32245

Publication History

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

ISBN Information

Print ISBN: 9780470375334

Online ISBN: 9780470314555

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Keywords:

  • ac complex impedance;
  • dielectric constant;
  • dielectric loss;
  • reinforcing phase;
  • semiconductor

Summary

AC Complex impedance, dielectric constant, dielectric loss and dc resistivity are being used to probe the microstructure of ceramic matrix and polymer matrix composites in a non-destructive way. Results indicate that the volume fraction, size and shape of the reinforcing phase play a major role in determining whether the composite will behave as a dielectric or as a semiconductor. Fiber, whisker and particulate orientations can easily be discriminated with the ac measurements. DC measurements, on the other hand, are mostly dominated by the interconnected phase unless the percolation threshold has been exceeded. These measurements have the potential for in-line process monitoring as well as mechanical and environmental damage monitoring.