Effects of Flash Sintering Parameters on Insulation Performance of Ceramic Insulator

Ceramic outdoor insulators play an important role in electrical insulation and mechanical support because of the good chemical and thermal stability, which have been widely used in both transmission and distribution power system. However, the brittleness and surface discharge of ceramic material greatly limit the application of ceramic insulators. Therefore, flash sintering technology is used to improve the insulation performance of ceramic insulators. In this paper, the simulation model of producing the ceramic insulator by the flash sintering technology was set up. Using alumina powder as the specimen, the influences of electric field intensity and current density on the sintering speed, density and grain size were investigated. Using COMSOL Multiphysics, the geometric model was built, the boundary conditions were set, and the grid was divided. Obtained results show that the current density has significant effects on the ceramic density and grain size. The increase of current density can result in higher ceramic density and larger grain size. The intensity of electric field affects incubation time of flash sintering. With increasing the electric field intensity, incubation time shows the decreasing tendency and energy consumption are reduced. Ceramic insulators with the higher uniform structure and the smaller grain size show the better dielectric performance and the higher flashover voltage.