Microwave-Material Interaction in Oxide Ceramics with Different Additives

Abstract:

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A systematic study upon microwave (2.45 GHz frequency) and conventional heating (resistance heating furnace) was undertaken on porosity, grain growth and densification of commercial grade Al2O3-ceramics doped with MgO (aliovalent doping), with ZrO2 (grain boundary pinning) and with additives promoting elongated grain growth (LaAlO 3 and La2O3, AlPO4). Processes accompanied by a strong non-equilibrium situation, e.g., dissolution, segregation, vacancy formation, are influenced by the presence of the microwave field during heat treatment, visible on microstructure differences of microwave as compared to conventionally sintered samples. Regular grain growth is almost not affected by the microwave field, but the on-set of exaggerated grain growth and pore coalescence is delayed and occurs at higher density as compared to conventional sintering. Such microstructure differences seem to be more pronounced if the surface to volume ratio of the samples is low, therefore volumetric heating has a larger contribution to transport phenomena as compared to small samples.

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Periodical:

Edited by:

P. VINCENZINI

Pages:

845-850

DOI:

10.4028/www.scientific.net/AST.45.845

Citation:

M. Willert-Porada et al., "Microwave-Material Interaction in Oxide Ceramics with Different Additives", Advances in Science and Technology, Vol. 45, pp. 845-850, 2006

Online since:

October 2006

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Price:

$35.00

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