Accession Number : ADP007770

Title :   Microwave Heating of Cermets,

Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Bescher, Eric ; Mackenzie, John D.

Report Date : 27 APR 1992

Pagination or Media Count : 7

Abstract : Metals are known to reflect microwaves. For an electromagnetic wave at normal incidence on an ideal conducting surface, there is total reflection of the incident wave, and the electric field E is zero at the surface. In practice, however, no conductor is perfect, i.e. it has a finite conductivity Delta. This imperfectness of the conductor leads to a fraction of the incident energy entering the conductor and dissipating as heat. Therefore, it is possible to exploit the microwave losses in metals for the fabrication of metal-based composites by microwaves. An obvious method is the use of metal powder particles dispersed in a ceramic material. The aim of this paper is to explore some of the parameters involved in the use of metals for the microwave heating of ceramic-metal composites or cermets. Cermets can be of two kinds, oxide- and carbide-based, and can be developed in a wide number of compositions. They combine the useful properties of ceramic and metal materials into one system. In the present work, examples of microwave heating of chromium-alumina and copper-alumina mixtures are presented.

Descriptors :   *CERAMIC MATERIALS, *CERMETS, *MICROWAVES, *POWDER METALS, CARBIDES, CHROMIUM, CONDUCTIVITY, COPPER, ELECTRIC FIELDS, ENERGY, FABRICATION, HEAT, HEATING, LOSSES, METALS, MIXTURES, OXIDES, PARAMETERS, REFLECTION, SURFACES, ELECTROMAGNETIC WAVE REFLECTIONS, ALUMINUM OXIDES, MICROWAVE OVENS, SYMPOSIA.

Subject Categories : Ceramics, Refractories and Glass
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE