Investigation of deterioration mechanism of inorganic insulation under high temperature

Author

Mizutani, Yoshinobu ; Tetsuo, Ito ; Tatsuki, Okamoto ; Kumazawa, Ryoji ; Aizawa, Rie

Author_Institution

CRIEPI, Japan

Volume

1

fYear

2000

fDate

2000

Firstpage

29

Abstract

This paper describes the characteristics of inorganic insulators under high temperature. The test materials are mica, alumina-cloth and alumina-plate that are components of mica-alumina combined insulation that we have suggested to be able to use over 500°C. Initial breakdown voltage tests and metal diffusion tests under high temperature are carried out in nitrogen gas atmosphere. It is clear that because there are many openings in alumina-cloth, the breakdown voltage does not depend on temperature. And also it is clear that there is two metal behavior mechanisms. One is that the openings of the insulator are filled up with copper that is oxidized, the other is the metal diffuses in alumina-cloth not through the bulk but through the surface. Finally in combined insulation the breakdown voltage depends on the thickness of mica and the mica works as a barrier to metal diffusion

Keywords

alumina; composite insulating materials; diffusion barriers; electric breakdown; high-temperature effects; insulation testing; mica; surface diffusion; 500 C; Al₂O₃-Al₂O₃(K₂O)SiO₂; alumina-cloth; alumina-plate; breakdown voltage test; combined insulation; copper; deterioration mechanism; high temperature; inorganic insulation; inorganic insulators; metal diffusion; metal diffusion test; mica; mica-alumina; nitrogen gas atmosphere; Aging; Atmosphere; Breakdown voltage; Copper; Electrodes; Grounding; Indium tin oxide; Insulation testing; Nitrogen; Temperature dependence;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Insulation and Dielectric Phenomena, 2000 Annual Report Conference on

Conference_Location

Victoria, BC

Print_ISBN

0-7803-6413-9

Type

conf

DOI

10.1109/CEIDP.2000.885220

Filename

885220