AVS 57th International Symposium & Exhibition | |
Tribology Focus Topic | Wednesday Sessions |
Session TR+MN+NS+SS-WeM |
Session: | Influence of Atmosphere, Temperature, and Materials on Friction |
Presenter: | I.L. Singer, Naval Research Laboratory |
Correspondent: | Click to Email |
Gas phase lubrication, also called vapor phase lubrication, refers to processes in which the gas surrounding a sliding (or rolling) contact contributes to lubrication [1]. It has wide ranging applications from internal combustion engines to MEMS. Some gases simply condense on surfaces, others decompose and deposit lubricating films on the surface, e.g, hydrocarbon films decompose and deposit graphite. Some can be made to react on the surface, as do various monomers that tribopolymerize and form lubricious third bodies at the contact. Alternatively, gases can react with the surface to form films; the most ubiquitous example is the oxide film formed on metals, which prevents (on earth, but not in outer space) surfaces from weld upon contact. Reaction films have been studied extensively by surface scientists; less well understood are tribofilms, films formed by rubbing action. Another important component to the lubrication process is film removal, which can occur during sliding or rolling; the competition between film formation and film removal always needs to be considered. In some cases, gas lubrication provides low friction and low wear; in other cases, it can increase friction and wear. In this talk, I will review gas phase lubrication processes and present several gas phase lubrication studies that still mystify me.
[1] For overview, see http://nsfafresh.org/wiki/index.php?title=Gas_Phase_Lubrication