Improving the voltage holdoff performance of alumina insulators in vacuum by quasimetallizing or doping

Conference · Tue Jan 01 00:00:00 EST 1980

DOI:https://doi.org/10.1016/0378-4363(81)90049-8· OSTI ID:5222441

Miller, H. C.

The high voltage holdoff capability of insulators may be improved by changing the material of the insulator or by a proper choice of geometry for the device using the insulator. Results applicable to insulators in various ultrahigh vacuum devices were desired, so work on modifying an alumina ceramic insulator material was selected. It was found that treatment of the surface of an alumina insulator with coatings incorporating varying amounts of Cr, Mn, and Ti can significantly increase the vacuum voltage holdoff capability of the insulator (up to 25%). During processing (quasimetallizing) the coating penetrates into the alumina, so it is insensitive to mechanical damage. This quasimetallize treatment is also compatible with subsequent metallizing and brazing of the alumina insulator. A 7 Mn:1 Ti coating mix performed very well, being found to be as effective on a 94% Al/sub 2/O/sub 3/ alumina as on the previously investigated 95% Al/sub 2/O/sub 3/, 1% Cr/sub 2/O/sub 3/ alumina. Mixes of 6 Mn:1 Ti:1 Cr and 6 Mn:3 Cr performed about as well as the 7 Mn:1 Ti mix, but no better.

• Research Organization: General Electric Co., St. Petersburg, FL (USA). Neutron Devices Dept.
• DOE Contract Number: AC04-76DP00656
• OSTI ID: 5222441
• Report Number(s): GEPP-OP-476; CONF-800903-2; TRN: 80-014757
• Resource Relation: Journal Volume: 104; Journal Issue: 1-2; Conference: 6. international conference on high voltage microscopy, Antwerp, Belgium, 1 Sep 1980
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
ELECTRICAL INSULATORS
PERFORMANCE
SURFACE COATING
ALUMINIUM OXIDES
BREAKDOWN
CERAMICS
CHROMIUM
DOPED MATERIALS
MAGNESIUM
TITANIUM
ULTRAHIGH VACUUM
ALKALINE EARTH METALS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
DEPOSITION
ELECTRICAL EQUIPMENT
ELEMENTS
EQUIPMENT
MATERIALS
METALS
OXIDES
OXYGEN COMPOUNDS
TRANSITION ELEMENTS
420800* - Engineering- Electronic Circuits & Devices- (-1989)