Dielectric properties of alumino-silicate ceramic material

Ceramic materials are of great importance in the area of high voltage insulators. They have an advantage in that the raw material is widely 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 material was studied in a sandwich structure (Al/ceramic/Al). This structure was obtained by sputter deposition of aluminium films on the two sides of ceramic samples. The dielectric constant and the dielectric loss factor were measured with an AC bridge in the frequency range 10 to 10/sup 5/ Hz. The DC electrical resistivity and thermo-mechanical properties of this material were also studied.