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Finite-Difference Time-Domain (FDTD) Simulation of Microwave Sintering in Multimode Cavities

Published online by Cambridge University Press:  25 February 2011

Ray L. Smith ,
Magdy F. Iskander ,
Octavio Andrade  and
Hal Kimrey
Ray L. Smith
Affiliation:
The first three authors are with the Department of Electrical Engineering, University of Utah, Salt Lake City, UT 84112. Mr. Hal Kimrey is with Oak Ridge National Laboratory, Oak Ridge, TN 37831
Magdy F. Iskander
Affiliation:
The first three authors are with the Department of Electrical Engineering, University of Utah, Salt Lake City, UT 84112. Mr. Hal Kimrey is with Oak Ridge National Laboratory, Oak Ridge, TN 37831
Octavio Andrade
Affiliation:
The first three authors are with the Department of Electrical Engineering, University of Utah, Salt Lake City, UT 84112. Mr. Hal Kimrey is with Oak Ridge National Laboratory, Oak Ridge, TN 37831
Hal Kimrey
Affiliation:
The first three authors are with the Department of Electrical Engineering, University of Utah, Salt Lake City, UT 84112. Mr. Hal Kimrey is with Oak Ridge National Laboratory, Oak Ridge, TN 37831
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Abstract

Microwave sintering of ceramics in multimode cavities, particularly the use of picket-fence arrangements, has recently received considerable attention. Various types of ceramics have been successfully sintered and, in some cases, a desirable and unique “microwave effect” has been observed.

At present, various aspects of the sintering process such as sample sizes and shapes, types of insulations, and the desirability of including a process stimulus such as SiC rods are considered forms of art and highly dependent on human expertise. The simulation of realistic sintering experiments in a multimode cavity may provide a better understanding of critical parameters involved and allow for the development of guidelines towards the optimization of the sintering process.

In this paper, we utilize the FDTD technique to model various geometrical arrangements and material compatibility aspects in multimode microwave cavities and to simulate realistic sintering experiments. The FDTD procedure starts with the simulation of a field distribution in multimode microwave cavities that resembles a set of measured data using liquid crystal sheets. Also included in the simulation is the waveguide feed as well as a dielectric loading plate placed at the base of the cavity. The FDTD simulation thus provides realistic representation of a typical sintering experiment. Aspects that have been successfully simulated include types of insulation, role of SiC rods on the uniformity of the resulting fields, problems that may result from presence of thermocouples, and the possible shielding effects that may result from excessive use of SiC. These results as well as others showing the electromagnetic fields and power-deposition patterns in multiple ceramic samples are presented.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 269: Symposium L – Microwave Processing of Materials III , 1992 , 47
Copyright
Copyright © Materials Research Society 1992

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References

REFERENCES

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