Microwave sintering of alumina using four single-cavity modes

In this study, alumina ceramics were sintered with 2.45-GHz microwaves in a cylindrical single-mode microwave cavity using four resonant cavity modes: TM111, TE112, TE113, and TM013. The mass density and grain size of sintered specimens were found to be relatively uniform with respect to both (i) the radial position within a given specimen and (ii) the cavity mode used to sinter the specimen. However, the initial power required to "couple" the field to the casket/specimen system and the power needed to reach and maintain the sintering temperature (1500 degrees C) were both functions of the cavity mode.