Simulation of Microwave Sintering of Ceramic Bodies with Complex Geometry

A. Birnboim and Y. Carmel
Institute for Plasma Research
University of Maryland, College Park, Maryland 20742

101st Annual Meeting & Exposition, The American Ceramic Society
Indianapolis, IN, April 25-28, 1999

ABSTRACT. Microwave sintering is a complex process combining the propagation and absorption of electromagnetic waves, heat transport, and densification that changes both the macroscopic shape and microstructure morphology. A dynamic balance between the rate of electromagnetic energy absorbed and the rate of surface energy loss leads to temperature gradients. The gradients generated in a ZnO green body of a complex geometry were studied theoretically using various microwave sintering approaches. We found that: (a) dual frequency (2.45 GHz and 30 GHz) processing leads to reduction in the duration of the temperature gradients, and (b) an increase in the heating rate from 5 to 1400oC/min reduces the total required microwave energy by a factor of 55.

Work supported by AFOSR, Ceramic Materials Program, Grant No. F496209710270.