Accession Number : ADA324743

Title :   Enhancement of Multifrequency Microwave Processing of Ceramics Using Microstructure Modification.

Descriptive Note : Final rept. 1 Aug 96-31 Jan 97,

Corporate Author : MARYLAND UNIV COLLEGE PARK

Personal Author(s) : Calame, J. P. ; Carmel, Y.

PDF Url : ADA324743

Report Date : 31 JAN 1997

Pagination or Media Count : 18

Abstract : A method to increase the loss tangent in a ceramic green body by modifying the nature of the interparticle contact areas is described. Such an increase in loss tangent, achieved through modifying the ceramic microstructure with material of the same chemical composition as the parent ceramic, will make rapid microwave sintering possible without altering the chemical stability of the system. For research purposes, the method of infusing a ZnO green body with a 0.053 M zinc acetate solution was selected. Following the infusion, a gel of hydrous Zn(OH)2 is formed in the pores through the action of aqueous ammonia, and ZnO is created by subsequent heating. A test sample was fabricated and subjected to this treatment. Dielectric properties in the 0.2-10.0 GHz regime were measured before and after treatment. The test sample showed a substantial increase in dielectric loss that is consistent with improved interparticle contact.

Descriptors :   *CERAMIC MATERIALS, *DIELECTRIC PROPERTIES, *ZINC OXIDES, *SINTERING, MICROSTRUCTURE, MODIFICATION, MICROWAVES, AMMONIA, TANGENTS, HYDROXIDES, ACETATES.

Subject Categories : Ceramics, Refractories and Glass
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE