HIGH-TEMPERATURE OXIDATION PROTECTIVE COATINGS FOR VANADIUM-BASE ALLOYS.
Abstract
The objective of this program was the development of oxidation-protective coatings for vanadium-base alloys for use at 1800 to 2500F. Specifically, the effect of the pack-siliconizing process and the silicide coating itself on the mechanical properties of 0.020 in. thick sheet of V-60Cb-1Ti (weight per cent) has been studied. Results indicate that both of the above parameters have little effect on strength, but causes some reduction in tensile ductility. However, the tensile transition temperature remains less than -320F after coating. Also, there is little or no embrittlement of this coated sheet after twenty-five 4 hr oxidation cycles at temperatures up to 2300F in static laboratory air. At reduced pressures, 100-1,000 microns useful life is at least ten 2 hr cycles at the above temperatures. Initial development of an oxidation resistant slurry or liquid cementation type of coating for V-60Cb-1Ti has been completed. Slurry compositions containing tin, silicon, silver, copper, aluminum, and columbium have been investigated; several of these show good coverage, even at corners and edges. The static oxidation life of other vanadium-base alloys, coated by the pack-siliconizing process, has also been investigated. V-40Cb-30Ta-1Ti, the most promising of these alloys, has an oxidation life of about 50 hr at 2200F, and less under cyclic conditions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1964
- Accession Number
- AD0611376
Entities
Organizations
- IIT Research Institute