Application of solid lubricants

The application of solid lubricants are-

• They are used either in the form of dry powered or mixed with water or oil so that they may stick firmly to the metal surfaces the suspension is stabilized by using emulsifying agents like tannin.
• The suspension of graphite in water is known as aqua- dag and that in oil is known as oil –dag.
• Aqua – tag is used where oil-free lubrication is required.
• Oil – dag used as lubricant in internal combustion (IC) engines the compression of the air-fuel mixture.
• It is used as a lubricant in air compressors, railway track joints, spacecraft, nuclear reactor etc where oil layer cannot be maintained due to various reasons.
• The solid lubricating film made from 70% MoS2, 7% graphite bonded with 23% silicates can withstand extreme temperature, 1000 atmosphere pressure and mixed nuclear radiations as in case of spacecraft.
• Metals with low melting points are used to as solid lubricants in steel bearings which reduce the coefficient of friction from 0.8 to 0.05.
• Solid lubricants like Teflon is used to lubricate oxygen valves, periscopes, underwater mechanism, brass cartridge etc due to its low coefficient of friction.