Microwave sintering of large alumina bodies

The application of microwaves as an energy source for materials processing of large alumina bodies at elevated temperatures has been very limited to date. Due to the restrictions inherent to the process, most work has concerned itself with small laboratory samples. The nonuniformity of the microwave field within a cavity subjects large alumina bodies to areas of concentrated energy, resulting in uneven heating and subsequent cracking. Smaller bodies are not significantly affected by field nonuniformity due to their smaller mass. This work will demonstrate a method for microwave sintering of large alumina bodies while maintaining their structural integrity. Several alumina configurations were successfully sintered using a method which creates an artificial field or environment within the microwave cavity. 4 refs., 4 figs