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Studies of Nonthermal Effects During Intense Microwave Heating of Crystalline Solids

Published online by Cambridge University Press:  25 February 2011

John H. Booske ,
Reid F. Cooper ,
Leon McCaughan ,
Sam Freeman  and
Binshen Meng
John H. Booske
Affiliation:
Electrical and Computer Engineering Dept., University of Wisconsin, Madison, Wl 53706
Reid F. Cooper
Affiliation:
Materials Science and Engineering Dept., University of Wisconsin, Madison, WI 53706
Leon McCaughan
Affiliation:
Electrical and Computer Engineering Dept., University of Wisconsin, Madison, Wl 53706
Sam Freeman
Affiliation:
Materials Science Program, University of Wisconsin, Madison, WI 53706
Binshen Meng
Affiliation:
Electrical and Computer Engineering Dept., University of Wisconsin, Madison, Wl 53706
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Abstract

Reports of enhanced sintering rates associated with microwave heating may be due to nonthermal lattice fluctuation statistics. Recent theoretical analyses reviewed in this paper confirm the feasibility of this phenomenon for a wide variety of situations involving very different microwave absorption mechanisms. For materials with weak microwave absorption coefficients, the effect is expected to be uniformly distributed throughout the volume. For strongly absorbing materials, however, the effect is expected to be concentrated near the material surface, with a characteristic exponential penetration depth of Lnt ∼ 10 - 100 μm. An “observable” nonthermal effect depends on the relative magnitude of the microwave electric field strength |E| and the lattice ion energy relaxation rate γ with the most pronounced effects occurring for larger values of |E| and smaller values of γ.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 269: Symposium L – Microwave Processing of Materials III , 1992 , 137
Copyright
Copyright © Materials Research Society 1992

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References

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