The Use of Alumino-Silicate Ceramic Material in High Voltage: Thermo-Mechanical and Dielectric Properties

In the conception of high voltage isolators the thermo-mechanical and dielectric properties of ceramic materials have a great importance. These materials present the advantage that the raw material is largely available. Electrotechnical porcelain is a clever compromise between electrical, thermal and mechanical resistances. The conceived samples must be tested within conditions that reproduce normal or accidental stresses to which insulators may be subjected while in use. In this paper, the dielectric properties of alumino-silicate was studied in a sandwich structure. This structure was obtained by sputtering deposition of aluminium films in the two sides of ceramic samples. The dielectric constant and the dielectric loss factor were measured with an AC bridge where the frequency was ranging from 20 to 105 Hz. The electrical DC resistivity of the samples was measured and the thermo-mechanical properties of this material were studied.