Accession Number:

AD0436294

Title:

ALKALI METAL RESISTANT WIRE

Descriptive Note:

Technical Report

Corporate Author:

WESTINGHOUSE ELECTRIC CORP LIMA OH LIMA United States

Report Date:

1964-04-15

Pagination or Media Count:

167.0

Abstract:

A ceramic coated conductor system was developed that was unaffected by 172 hours exposure to K potassium vapor at 850 C. This system was Metco 201 Zirconia, plasma sprayed on nickel aluminide coated Nickel clad Silver AWG 8 Sylvania wire. This system, however, is not suitable for electrical operation at 850 C since the resistance of the zirconia coating drops to about 5 ohms at 600 C. Overcoating the zirconia with aluminum nitride by a vapor plating technique results in a resistance at 850 C in argon for the multicoat of 1.8 x 10 to the 4th power ohms. The aluminum nitride overcoated zirconia is unaffected by 172 hours exposure. A number of high purity insulators were found to be resistant to potassium vapor at 850 C. These were alumina, magnesia, and strontium zirconate. A primary problem with plasma spray coatings of these materials is loss of adhesion in the potassium vapor even when a nickel aluminide undercoat is used.

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE