Microwave Sintering of ZnO Varistor Ceramics

ZnO nanopowders prepared by the Sol-Gel method were sintered by microwave. The microstructure of the material was analysed by XRD and SEM. The I - V properties of varistor weremeasured by a stabilized dc power source. Compared with the conventional sintering, microwavesintering promptes grain growth and shortenes sintering time. When grain sizes are the same, thetemperature of microwave sintering can be lower than that of conventional sinering. Microwavesintering has the ability to enhance the density of ZnO varistor ceramic and to obtain good electricpropertises. Hence, microwave sintering is a newly effective method for processing ZnO varistorceramic .