DENSIFICATION AND GRAIN-GROWTH OF ALUMINA BY MICROWAVE PROCESSING

Highly pure submicron alumina powdered compacts were sintered to a nea r theoretical density of 99.7% by 2.45 GHz microwave processing. Micro wave heating showed enhanced densification processing and short sinter ing time as compared to conventional heating. However, a relatively la rge grain growth was observed at temperatures below 1400 degrees C. It was found that there is a comparable grain size of 2.5 mu m for the s amples sintered by microwave and by conventional methods as they reach ed near theoretical density. (C) 1998 Elsevier Science B.V. All rights reserved.