Accession Number : AD0488447

Title :   DEVELOPMENT OF PRODUCTION METHODS FOR HIGH-TEMPERATURE COATING OF LARGE TANTALUM PARTS.

Descriptive Note : Final technical rept. 1 Jun 63-1 Jun 65,

Corporate Author : SYLVANIA ELECTRIC PRODUCTS INC HICKSVILLE NY SYLCOR DIV

Personal Author(s) : Sama, L. ; Reznik, B.

Report Date : AUG 1966

Pagination or Media Count : 127

Abstract : A Sn-27Al-5.5Mo slurry coating system previously developed for oxidation protection in the 1100-3300 F range was scaled up to coat tantalum structures 24x24x36 inches. Parts could be coated by dipping, spraying or brushing, and/or combinations of each. A vacuum slurry dip process was also developed which is capable of coating faying surfaces and complex welded geometries. Run-off of the Sn-rich layer during diffusion treatment, previously inherent in Sn-Al-base coatings, was effectively eliminated for large part sizes through the use of a single-cycle coating of Sn-27.5Al-6.9Mo. Initial results indicate that this coating composition has improved resistance to oxidation under high mass-flow conditions such as would be experienced during reentry. Considerable progress was made in the area of coating repair. Techniques were developed for stripping and recoating of defective or oxidized parts. Production proof was demonstrated with 11 leading edge segments, 11 large corrugated heat shield panels, hundreds of smaller components, and several thousand samples which were reproducibly coated by processes developed in this program. The Sn-27Al-5.5Mo coating applied to the Martin leading edge segments successfully withstood several cycles of typical reentry profile. The effects of coating and processing on distortion of prototype hardware coated in this program were found to be minor. (Author)

Descriptors :   *TANTALUM), *TANTALUM ALLOYS), (*TIN COATINGS, (*PROTECTIVE TREATMENTS, (*CORROSION INHIBITION, COATINGS), (*REFRACTORY METALS, COATINGS), TIN ALLOYS, ALUMINUM ALLOYS, MOLYBDENUM ALLOYS, HIGH TEMPERATURE, THICKNESS, CLEANING, HEAT SHIELDS, LEADING EDGES, MICROSTRUCTURE.

Subject Categories : Coatings, Colorants and Finishes
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE