Microwave sintering of Ce-Y-ZTA composites

Microwave processing of ceramic materials--especially the sintering of Al{sub 2}O{sub 3}, ZrO{sub 2} and their composites--has been investigated during the past decade by many researchers. Electromagnetic waves interact with ceramic materials, leading to volumetric heating by dielectric loss. This enhances the sintering process and decreases sintering active energy and densification temperature. Microwave heating also has the potential for energy and cost savings when compared with conventional heating. Zirconia-toughened alumina (ZTA) has received attention for its rapid densification in a microwave furnace. This article examines the batch microwave sintering of ZTA--30 wt% ceria-yttria-stabilized tetragonal zirconia polycrystals (Ce-Y-TZP) + 70 wt% Al{sub 2}O{sub 3}--including: (1) the microwave process in a multimode cavity with a hybrid heating structure; (2) the flexural strength, fracture toughness and wear resistance of the microwave-sintered materials; (3) the relationship between sintering temperature and microstructure/mechanical properties of the sintered samples; and (4) the comparison between microwave-sintered and conventionally sintered materials.