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Effects of the Susceptor Dielectric Properties on the Microwave Sintering of Alumina
Author(s) -
Heuguet Romain,
Marinel Sylvain,
Thuault Anthony,
Badev Alexandre
Publication year - 2013
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12623
Subject(s) - susceptor , materials science , sintering , microstructure , microwave , composite material , electrical resistivity and conductivity , dielectric , electric field , optoelectronics , electrical engineering , physics , epitaxy , layer (electronics) , quantum mechanics , engineering
Microwave sintering of alumina has been carried out using SiC and Y‐ ZrO 2 based susceptors. The microstructure of the sintered samples has been rigorously compared and correlated to the heating behaviour of the susceptor used. It was found that the nature of the susceptor highly influences the sintering behaviour of alumina. The results show that at high temperatures, the electrical conductivity of the SiC susceptor tends to screen the incident electric field, thus resulting in a surface heating of the alumina sample material. When using ZrO 2 susceptor, the microstructure analysis of the sintered alumina samples reveals a volumetric heating, which is a signature of the microwave dielectric loss mechanism. This could be explained by the lower ZrO 2 electrical conductivity compared to the SiC one. The simulation results confirm this behaviour, particularly showing that in the presence of ZrO 2 , the intensity of the electric field within the sample is higher than the one when SiC susceptor is used. Basically, the results of the simulation data are in good agreement with our experimental results. Although the SiC based susceptor is usually used in the microwave heating of materials, the ZrO 2 based susceptor presents numerous advantages over the SiC one, especially in term of direct microwave heating contributions.