A RESEARCH PROGRAM ON THE INVESTIGATION OF SEAL MATERIALS FOR HIGH TEMPERATURE APPLICATION. Period covered: January 1, 1957 through March 31, 1958

Technical Report · Tue Apr 01 00:00:00 EST 1958

OSTI ID:4281611

Baskey, R H

Novel rotating-seal materials for potential aircraft applications at high speed and high temperatures were developed and tested under conditions of no external lubrication. These materials were arrived at after a systematic study of the wear behavior of pure refractory metals, binary alloys of refractory metals bonded with nickel. and ternary alloys of refractory metals honded with nickel and infiltrated with silver. Tests were conducted to determine the benefit derived from additions of nickel or silver to the refractory hard metals. The nickel acts as a tough, oxidation-resistant matrix. The silver was added to act as a lubricant as it softens at high temperatures. This aids the shearing action between mating surfaces and lowers the surface friction. Two ternary alloys prepared by powder metallurgy techniques and consisting of high percentages by weight of a refractory hard metal, with nickel and silver additions, show superior wear qualities when run against either tool steel or Inconel. Tests were made at sliding speeds of 30,0000 fpm and ambient temperatures up to l350 deg F, The best alloys contained either tungsten boride (WB) or chromium nitride (CrN) as the hard refractory metal. The WB alloy exhibited a constant wear rate at all temperatures against tool steel. The wear rate of the CrN alloy decreased at the higher displayed a decrease in wear rate at ambient temperatures over 600 deg F.The wear decreased as a function of temperature for several ternary alloys against tool stoel. An unimpregnated graphite seal coated with an oxidation resistant layer of zirconium carbide showed improved wear properties over a regular graphite impregnated seal at an ambient temperature of l050 deg F and sliding speeds of l4,000 fpm against stainless steel type 303. The finest wear performance was attained when Kentanium Kl G2B ran against Kentanium Kl62B at sliding specds of 14,000 fpm in an ambient temperature of 1100 deg F. It is hypothesized that the wear process is drastically influenced by the oxidation occurring on the rubbing surfaces and that with proper choice of materials, stable. complex oxides are formed which provide the correct solid lubricating film on each component and maarkedly lower the wear rate as the temperature is increased. (auth)

• Research Organization: Horizons, Inc., Cleveland
• DOE Contract Number: AF33(616)-3891
• NSA Number: NSA-13-004724
• OSTI ID: 4281611
• Report Number(s): WADC-TR-58-181; AD-155689
• Resource Relation: Other Information: Project title: CERAMIC AND CERMET MATERIALS. Task title: CERAMIC AND CERMET MATERIALS DEVELOPMENT. Orig. Receipt Date: 31-DEC-59
• Country of Publication: United States
• Language: English

Related Subjects

METALLURGY AND CERAMICS
ADDITIVES
AIRCRAFT
ALUMINUM ALLOYS
BONDING
CERAMICS
CERMETS
CHROMIUM ALLOYS
CHROMIUM NITRIDES
COATING
EFFICIENCY
FILMS
FRICTION
HIGH TEMPERATURE
IMPREGNATION
IMPURITIES
INCONEL ALLOYS
LAYERS
LUBRICATION
MATERIALS TESTING
NICKEL
NICKEL ALLOYS
NIOBIUM ALLOYS
OXIDATION
PLANNING
POWDER METALLURGY
PREPARATION
REFRACTORIES
ROTATION
SEALS
SHEAR
SILVER
SOLIDS
STABILITY
STAINLESS STEELS
STEELS
SURFACES
TEMPERATURE
TENSILE PROPERTIES
TITANIUM ALLOYS
TUNGSTEN BORIDES
USES
VELOCITY
WEAR
ZIRCONIUM CARBIDES