Microwave processing and properties of ceramics with different dielectric loss

Microwave sintering behaviors of three kinds of ceramics with different die lectric loss [Al2O3, Ce-Y-ZrO2 and lead-based relaxer ferroelectrics (PMZ N T)] in 2.45 GHz microwave furnace were described. Measurement of sample den sities showed an enhancement of the sintering processing for all materials studied. Fo PMZNT and Ce-Y-ZrO2 with high dipolar loss or ionic conductive loss, the associated microstructure examined using scanning electron micros copy showed that microwave-sintered compacts produced much finer grain size s at near theoretical density compared to conventional sintering. Resulting material properties, such as flexure strength and breakdown strength, were also increased due to developed microstructure in microwave processing. Ho wever, a comparable grain size and properties were observed for high pure A L(2)O(3), with low dielectric loss in microwave and conventional methods. ( C) 1999 Elsevier Science Limited. All rights reserved.