Transactions of the INDIAN CERAMIC SOCIETY Vol. 64 2005
Microwave Sintering of Titania
S. Das, A. K. Mukhopadhyay, S. Datta and D. Basu
Pages : 143-148
Microwave processing was employed to sinter commercial titania powder to obtain rutile as the major phase in the sintered product. About 96% of theoretical density was achieved by exposing the powder in microwave for 1 h at 1300°C. The maximum density obtained for titania ceramics sintered with identical parameters in a conventional muffle furnace was only about 85% of theoretical density, indicating superiority of the previous technique. The dielectric properties of the microwave sintered titania showed increased dielectric constant and decreased dissipation factor values compared to conventionally sintered one. However, DC electrical resistivity was almost comparable for both the samples. Further, the conventional sintering even up to 1300°C did not yield rutile as the major phase in the densified body. The kinetics of rutile formation in the microwave sintered sample was also studied as a function of temperature (900°-1300°C). Scanning electron microscopy (SEM) on the polished surface of the sintered specimens revealed that the microwave processed ones had finer microstructure than that of the conventionally sintered titania ceramics.