HIGH-TEMPERATURE OXIDATION PROTECTIVE COATINGS FOR VANADIUM-BASE ALLOYS. Final Report, June 12, 1961-July 11, 1962
More than forty coating materials were investigated for the oxidation protection of V--Nb alloy sheet specimens at 2000 to 2400 deg F and above. The wide range of coatings included flame-sprayed ceramics, roll-bonded Fe -- Cr -- Al, slurry-coated or fused Zn, Al, Ni, and other alloys, liquidphase sintered chromium-noble metal alloys, sintered intermetallic compounds, and pack-cemented diffusion-type coatings. The most promising system studied was a diffusion-type silicide applied to V--1 wt% Ti--60 wt% Nb by a pack cementation process. This coating afforded excellent protection for at least 1000, 290, and 50 hours in static air at 2000, 2200, and 2500 deg F, respectively, and a remarkable capacity for tolerating defects was noted. Silicide-coated specimens withstood exposure to an oxyacetylene flame for 4 hours at temperatures up to 2800 deg F, and tensile and stress-rupture tests in 2000 deg F air showed no degradation of properties of the vanadium alloy base. Nickel, flamedirectly to elevated- temperature air, and the coating life was 150 and 50 hours at 2000 and 2200 deg F, respectively. A glassy phase which developed during exposure may have contributed to the ability to seal over defects for lengthy periods. As flame- sprayed, the composites could be plastically deformed, but the coatings became relatively brittie after Ni--V--Nb compounds formed at elevated temperatures. The alloy Fe--25 wt% Cr--5 wt% Al rollbonded to V--5 wt%--20 wt% Nb was protective for about 80 hours at 2000 deg F; good bonds were not obtained on the higher-Nb alloy. Greatly reduced coating life (<5 hours at 2000 deg F) was measured for most of the other systems studied. In most cases, coatings survived much longer on V--1 wt% Ti--60 Nb than on the vanadium-rich alloy. (auth)
- Research Organization:
- Illinois Inst. of Tech., Chicago. Armour Research Foundation
- NSA Number:
- NSA-16-027587
- OSTI ID:
- 4803845
- Report Number(s):
- ARF-2227-6
- Country of Publication:
- United States
- Language:
- English
Similar Records
HIGH-TEMPERATURE OXIDATION PROTECTIVE COATINGS FOR VANADIUM-BASE ALLOYS. Bimonthly Report No. 1, June 12, 1961-August 11, 1961
HIGH-TEMPERATURE OXIDATION PROTECTIVE COATINGS FOR VANADIUM--BASE ALLOYS. Final Report, September 13, 1962- August 12, 1963
Related Subjects
ALUMINUM
ALUMINUM ALLOYS
BONDING
CERAMICS
CHROMIUM ALLOYS
COATING
DIFFUSION
FAILURES
HIGH TEMPERATURE
INTERMETALLIC COMPOUNDS
IRIDIUM ALLOYS
IRON ALLOYS
LIQUID METALS
MATERIALS TESTING
METALS, CERAMICS, AND OTHER MATERIALS
NICKEL
NIOBIUM ALLOYS
OSMIUM ALLOYS
OXIDATION
PALLADIUM ALLOYS
PLATES
PLATINUM ALLOYS
RHODIUM ALLOYS
ROLLING
RUTHENIUM ALLOYS
SILICIDES
SINTERING
SLURRIES
SPUTTERING
STABILITY
STRESSES
TENSILE PROPERTIES
TITANIUM ALLOYS
VANADIUM ALLOYS
ZINC