Because of their crystalline structure, solid lubricants are used when liquid (lubricating oil) or semi-solid lubricants (grease) fail. As a rule, they are used as additives in these lubricants, although they are occasionally also used as sole lubricants. Maintenance-free plain bearings such as the DEVA® product range contain solid lubricants, meaning additional lubrication is not required depending on operating conditions.
Solid lubricants include graphite and molybdenum disulfide. There are also a variety of other materials, such as metal soaps, sulfide compounds or plastics such as PTFE. Ceramic particles or soft metals can have a positive influence on the tribological properties in dry running without directly belonging to the family of solid lubricants.
Tasks of solid lubricants: