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Assessment of Homogeneity of Extruded Alumina-SiC Composite Rods Used in Microwave Heating Applications by Impedance Spectroscopy

Published online by Cambridge University Press:  21 May 2013

Justin R. Brandt  and
Rosario A. Gerhardt
Justin R. Brandt
Affiliation:
School of Materials Science and Engineering, Georgia Institute of Technology Atlanta, GA 30332-0245
Rosario A. Gerhardt
Affiliation:
School of Materials Science and Engineering, Georgia Institute of Technology Atlanta, GA 30332-0245
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Abstract

Composite rods consisting of Alumina (Al2O3) and Silicon Carbide whiskers (SiCw) are used to fabricate microwave cooking racks because they effectively act as a microwave intensification system that allows cooking at much faster rates than conventional microwave ovens. The percolation behavior, electrical conductivity and dielectric properties of these materials have been reported previously. However, it has been observed that the electrical response of the extruded bars is a function of the rod length and that long rods show substantially different behavior than thinner disks cut from them. A percolation model has been proposed that describes the effect of the alignment of the semiconducting SiC whiskers and the quality of the interfaces present in the composite rods: SiC-SiC and SiC-Al2O3-SiC for example. This study was undertaken with the goal of testing out whether the response of the individual sections could be used to generate the response of the full length rods and to assess the importance of the homogeneous distribution of the SiC fillers on the resultant impedance response.

Keywords

microwave heatingmicrostructurecomposite
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1538: Symposium FF – Compound Semiconductors: Thin-Film Photovoltaics, LEDs and Smart Energy Controls , 2013 , pp. 323 - 328
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Mebane, D.S. and Gerhardt, R.A., “Interpreting Impedance Response of Silicon Carbide Whisker/Alumina Composites Through Microstructural Simulation, ” J.Am.Ceram.Soc. 89(2), 538–543, 2006.CrossRefGoogle Scholar
Bertram, Brian D. And Gerhardt, Rosario A., “Room Temperature Properties Of Electrical Contacts to Alumina Composites Containing Silicon Carbide Whiskers, ”J. Applied Phys. 105, 074902, 2009.CrossRefGoogle Scholar
Bertram, B.D. and Gerhardt, R.A., “Frequency-dependent dielectric properties and percolation behavior of alumina filled with SiC whiskers, ” J. Am. Ceram. Soc. 94(4), 1125–1132, 2011.CrossRefGoogle Scholar
Bertram, B. D., Gerhardt, R. A., and Schultz, J. W., “Extruded and Pressureless-Sintered Al2O3–SiCw Composite Rods: Fabrication, Structure, Electrical Behavior, and Elastic Modulus” J. Am. Ceram. Soc. 94, 4391, 2011.CrossRefGoogle Scholar
Bertram, Brian D., Gerhardt, Rosario A., Schultz, John W., “Impedance response and modeling of composites containing aligned semiconductor whiskers: Effects of dc-bias partitioning and percolated cluster length, topology, and filler interfaces” J. Appl. Phys. 111, 124913, 2012.CrossRefGoogle Scholar
Quantrille, T. E., “Novel Composite Structures for Microwave Heating and Cooking”; in 41st Annual Microwave Symposium. International Microwave Power Institute, Vancouver, BC, 2007.Google Scholar
Ou, R., Gerhardt, R.A., Marrett, C., Moulart, A., and Colton, J.S., “Assessment of percolation and homogeneity in ABS/carbon black composites by electrical measurements” Composites. Part B 34, 607, 2003.CrossRefGoogle Scholar
Zview Software, Scribner Associates, http://www.scribner.com/ Google Scholar
Barsoukov, Evgenij, Ross Macdonald, J., eds., Impedance Spectroscopy: Theory, Experiment, and Applications, John Wiley & Sons, 2005.CrossRefGoogle Scholar
Gerhardt, R., “Dielectric and Impedance Spectroscopy Revisited: Distinguishing Localized Relaxation from Long Range Conductivity, ” J. Phys. Chem. Solids. 55(12), 1491–1506, 1994.CrossRefGoogle Scholar
Gerhardt, R., “Microstructural Characterization of Composites via Electrical Measurements, ” Ceram. Eng. Sci. Proc. 15(5), 1174–1181, 1994.CrossRefGoogle Scholar