Tribological properties of alumina-boria-silicate fabric from 25 C to 850 C

Journal Article · Sat Jul 01 04:00:00 EDT 1989 · ASLE (American Society of Lubrication Engineers) Transactions; (USA)

DOI:https://doi.org/10.1080/10402008908981896· OSTI ID:5312101

Dellacorte, C ^[1]

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1. NASA, Lewis Research Center, Cleveland, OH (USA)

Demanding tribological properties are required of the materials used for the sliding seal between the sidewalls and the lower wall of the variable area hypersonic engine. Temperatures range from room temperature and below to operating temperatures of 1000 C in an environment of air, hydrogen, and water vapor. Candidate sealing materials for this application are an alumina-boria-silicate, ceramic, fabric rope sliding against the engine walls which may be made from copper- or nickel-based alloys. Using a pin-on-disk tribometer, the friction and wear properties of some of these potential materials and possible lubrication methods are evaluated. The ceramic fabric rope displayed unacceptably high friction coefficients (0.6 to 1.3) and, thus, requires lubrication. Sputtered thin films of gold, silver, and CaF2 reduced the friction by a factor of two. Sprayed coatings of boride nitride did not effectively lubricate the fabric. Static heat treatment tests at 950 C indicate that the fabric is chemically attacked by large quantities of silver, CaF2, and boron nitride. Sputtered films or powder impregnation of the fabric with gold may provide adequate lubrication up to 1000 C without showing any chemical attack. 8 refs.

• OSTI ID: 5312101
• Journal Information: ASLE (American Society of Lubrication Engineers) Transactions; (USA), Journal Name: ASLE (American Society of Lubrication Engineers) Transactions; (USA) Vol. 32; ISSN ASLTA; ISSN 0569-8197
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320302* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Materials
36 MATERIALS SCIENCE
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BORON COMPOUNDS
BORON OXIDES
CERAMICS
CHALCOGENIDES
ELEMENTS
ENGINES
FILMS
FLUID FLOW
FRICTION
GOLD
HEAT ENGINES
HYPERSONIC FLOW
INTERNAL COMBUSTION ENGINES
LUBRICANTS
LUBRICATING PROPERTIES
METALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RAMJET ENGINES
SEALS
SILICATES
SILICON COMPOUNDS
SLIDING FRICTION
SOLID LUBRICANTS
SPUTTERING
THIN FILMS
TRANSITION ELEMENTS
TRIBOLOGY