Microwave Dielectric Properties of 0.9Al2O3―0.1TiO2Ceramics Prepared by Aqueous Gelcasting

Theaqueous gelcasting was used to prepare 0.9Al2O3―0.1TiO2ceramics. The microstructures, phase compositions and microwave dielectricproperties of sintered 0.9Al2O3―0.1TiO2ceramics were investigated. With the help of proper calcination temperature(1200 )and continuous and slow cooling process as annealing treatment, the Al2TiO5secondary phase was successfully eliminated. Compared with conventional drypressing method, bigger grains, less pores and more uniform microstructures areobserved in the 0.9Al2O3―0.1TiO2 ceramicsprepared by aqueous gelcasting. Therefore, much better microwave dielectricproperties are obtained in the ceramics prepared by aqueous gelcasting with er = 10.71, Q x f = 20421GHz, tf = 1.3 x 10―6/ , whereas that of ceramics preparedby dry pressing are er = 10.89, Q x f = 11938GHz, tf = 1.4 x 10―6/ .