Electrical treeing in ceramic-based insulating materials (Ba TiO3 – SiO2).

Abstract

The process leading to the development of electrical trees in ceramic-based materials (BaTi03- Si02 system) under the influence of relatively low a.c. signals and induced vibration frequencies was studied. The breakdown strengths of the chosen material (Ba Ti03 system) was conducted under oil whereas the dielectric properties were determined by impendence method. It was observed that the tree-like structures were of two types and that the initiation could have been due to partial discharges that arose from microcracks, pores and other similar defects. This equally shows that the mechanism of the initiation of an a.c. tree and that of a d.c. trees are similar. Thus, if a.c. voltage is considered as a repetition of charging and discharging processes, then one can understand that some likeness could exist between the phenomena.


Keywords: Electrical treeing, ceramics, insulators, breakdown, micro cracks.


[Global Jnl Pure & Appl. Sci. Vol.9(3) 2003: 381-386]