Long-term lubrication of ceramics at high temperatures

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5212192

Lee, K Y

Use of high-performance ceramics as sliding components in engines can significantly increase fuel efficiency. However, a major problem that needs to be solved is the lubrication of ceramics at high temperatures. To study high-temperature lubrication of ceramics, an instrumented high-temperature-wear testing machine was designed and constructed. Unlubricated room temperature and high-temperature wear tests of aluminum oxide sliding against aluminum oxide showed very high wear rates, unsuitable for any long-term sliding applications. Based on wear tests conducted at room temperature with aluminum oxide against aluminum oxide using oil and sputter-deposited films of graphite of the thickness 200{Angstrom}, the following conclusions were drawn: (a) The friction mechanism in alumina with good surface finish at room temperature is adhesion, and (b) Significant reduction in friction and wear can be obtained without extraction of wear debris. (c) The dominant mechanism of wear in alumina at room temperature must be a combination of adhesion and brittle fracture. For high-temperature lubrication of alumina parts, a method of depositing solid lubricants or solid-lubricant mixtures of CaF{sub 2}, BaF{sub 2}, and Ag using colloidal suspensions was developed.

• Research Organization: Colorado State Univ., Fort Collins, CO (USA)
• OSTI ID: 5212192
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330100 -- Internal Combustion Engines
36 MATERIALS SCIENCE
360205* -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CERAMICS
CHALCOGENIDES
ENGINES
HEAT ENGINES
INTERNAL COMBUSTION ENGINES
LUBRICANTS
LUBRICATION
MECHANICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
SOLID LUBRICANTS
TEMPERATURE EFFECTS
TESTING
WEAR RESISTANCE