Accession Number : AD0830239

Title :   ELECTROPHORETIC DEPOSITION OF REFRACTORY METALS COATINGS.

Descriptive Note : Final technical rept. 28 Jun 65-31 Dec 67,

Corporate Author : VITRO LABS WEST ORANGE NJ

Personal Author(s) : Ortner, Martin H. ; Gebler, Kenneth A.

Report Date : FEB 1968

Pagination or Media Count : 182

Abstract : A program was conducted to optimize process variables, develop process controls, design equipment, and demonstrate techniques for the application, by electrophoretic methods, of high temperature oxidation resistant coatings to refractory metal components. Statistically designed, fractional factorial analyses were performed to identify those processing variables which critically affect the oxidation resistance of the Cr/Ti-Si coating for Cb-752 alloy and the Si/WSi2 coating for T-222 alloy. The critical processing variables (siliconization time and temperature for Cr/Ti-Si and coating thickness for Si/WSi2) were then optimized and oxidation tests were performed of the optimized coatings. Oxidation lives (1 hour cycles) ranged from 100 hours at 2500F to 16 hours at 2700F for Cr/Ti-Si, and from 55 hours at 2600F to 5 minutes at 3600F for Si/WSi2. The latter coating was nonprotective in a simulated reentry pressure profile test. Techniques were developed for application of the optimized coatings to complex shapes such as simulated leading edges, tubing, and open-ended single face corrugations, and a method was developed for isostatic pressing, if required, of coated corrugations. The electrophoretic method was also utilized to selectively coat a part of the surface of Cb-752 rod with Cr/Ti and the remainder of the surface with Cr/Ti-Si. (Author)

Descriptors :   *ELECTROPHORETIC COATINGS), *CORROSION INHIBITION), (*REFRACTORY COATINGS, (*REFRACTORY METAL ALLOYS, NIOBIUM ALLOYS, CORROSION RESISTANCE, CHROMIUM ALLOYS, TITANIUM ALLOYS, TUNGSTEN ALLOYS, POWDER ALLOYS, TANTALUM ALLOYS, DIFFUSION COATING, SILICON COATINGS, DEPOSITION, SILICIDES, COATINGS.

Subject Categories : Coatings, Colorants and Finishes
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE