Friction and wear maps of solid lubricating coatings, films, and powders

Solid lubricants designed for moving mechanical assemblies must display desirable coefficients of friction and maintain good durabihty in different operating environments. However, little data are available on the tribological properties, particularly the actual specific wear rates (dimensional coefficient of wear), of solid lubricating coatings, films, and powders in different environments. The solid lubrication systems have different characteristics under different conditions. A study on the friction and wear properties, e.g., coefficient of friction, coefficient of wear, and wear (endurance) life, of selected solid lubricants in different environments was carried out. Friction and wear mapping assisted evaluation of the performance for solid lubricants in their operating environment and in identifying lubricants and their operating conditions that could provide extremely low friction and negligible wear. For example, in vacuum, the DLC appears to drive the coefficient of wear to unacceptable values, while in air, the coefficient of friction is driven to higher values by the WS₂ and MoS₂. This is an abstract of a paper presented at the 2010 Society of Tribologists and Lubrication Engineers Annual Meeting (Las Vegas, NV 5/16-20/2010).