Accession Number:

AD0608510

Title:

OXIDATION RESISTANT HIGH TEMPERATURE PROTECTIVE COATINGS FOR TUNGSTEN

Descriptive Note:

Rept. for 15 May 1963-15 May 1964

Corporate Author:

THOMPSON RAMO WOOLDRIDGE INC CLEVELAND OH TRW ELECTROMECHANICAL DIV

Personal Author(s):

Report Date:

1964-07-01

Pagination or Media Count:

127.0

Abstract:

A controlled process has been estabilished for application of silicon-tungsten and titanium zirconium silicon-tungsten coatings to tungsten sheet. Protective capabilities of these coatings on arc cast and powder product tungsten sheet have been determined at one atmosphere air from 1600 to 3600F under cyclic conditions. Exposure at static pressures below 15 mm Hg air at 3400-3500F resulted in varying degrees of deterioration of the silicon-tungsten and titanium zirconium silicon-tungsten coatings. Under dynamic low pressure conditions 2000-2800 ftsec simulated air flow at 16-20 mm Hg both coatings were protective to tungsten and resisted erosion in the temperature range of 2900-3400F 180 to 325 BTUsq ftsec heat flux range. Various refractory compound mixtures plasma sprayed on tungsten sheet were not protective at elevated temperatures in air. A silicon-tungsten titanium nitride-boron nitride coating combination protected tungsten for short periods of time at 3700F. Tensile properties were determined for silicontungsten and titanium zirconium silicon-tungsten coated arc cast tungsten sheet at various temperatures to 3300F. In stress oxidation tests the same systems loaded at 20 percent of the yield strength showed essentially no creep after 1 hour at 3350F in air. The coatings were completely protective at this stress level.

Subject Categories:

  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE