Friction and Wear Testing at Cryogenic Temperatures

Abstract

In cryogenic environment components with interacting surfaces in relative motion (tribosystems) like beatings, seals and valves cannot be lubricated conventionally by using oils or greases. Therefore, they are critical in respect to wear and frictional heat generation. To obtain reliable data of the properties of conventional and advanced materials in cryogenic tribosystems, model wear tests at low temperatures are performed. Tests with polymer-steel couples verified that some polymers have a favorable tribological behavior at low temperatures. Coatings of amorphous carbon are on principle suitable for cryogenic tribosystems, but their behavior depends strongly on the composition and deposition method. The results of the tribological model tests of polymers show that the basic wear mechanisms of polymers, deformation and adhesion, are still acting at low temperatures but the increasing mechanical strength give rise to a reduced wear. Tests with hard carbon coatings show that they are appropriate for tribosystems in cryogenic environment. Temperature dependent low and high friction states show that further investigations on this material are necessary.