subject: Understanding A Little Bit More About Graphite Lubricant [print this page] Graphite is a form of carbon, which is silvery black in colour. Graphite is one of the predominant materials used as solid lubricant. The lamellar structure of graphite (the tendency to flake), in the form of dry powder, makes it ideal to decrease friction. Graphite may also serve as a liquid based lubricant. The lubrication film provides resistance to damage and also seizure resistance. As a dry lubricant, the powdered graphite reacts with vapour and the molecular bonding doesn't occur, leaving it dry and slippery. However, it doesn't bond well with the surface and thus keeps falling off, increasing the need to be applied often. Solid graphite lubricant is tolerant to temps of about 900 degree F. Higher temperatures than this leads to oxidation of graphite.
The liquid graphite lubricant is of various types. The graphite grease is designed to stick to the surface, where the grease will stop the graphite from falling off the work surface. Another mixture of graphite lubricants with liquid base is such that the liquid will evaporate when the mixture is painted on the surface, leaving the graphite to work to decrease friction.
As a dry lubricant, graphite might be used in some situations where wet lubricants may contribute to hazard as in electrical fittings or when lubricating substances such as wood. Also, graphite grease can tolerate higher heat than natural grease or any other lubricants.
Graphite may be used as an additive in lubricating oil to raise the thermal tolerance. They're also used as components of polymer based composite anti-friction coatings and form the second phase particles of metal based composite anti-friction coatings. They are used as molds for continuous casting and solid lubricant in metal forming.
Graphite is also utilised in continuous casting molds. The molds are forged from iso-statically pressed graphite. The low friction between the mold surface and solidifying metal ensures smooth extraction of the casting. The crystal structure of graphite offers low friction without the necessity of extra lubrication.
Graphite is characterized as organic and synthetic. Organic graphite is derived from mining. The refined graphite is consists of carbon, sulfur, SiO2 and Ash. The crystallizing quality of graphite is determined by the higher content of carbon, and better the lubricity and resistance to oxidation. Artificial graphite is sintered from high temperature and has very high carbon content of up to 99.5-99.9%, and is thus extremely good as a lubricant.
While the conventional automotive oils can not withstand the high temps, graphite can serve as lubricants in automotive engines which reach temperatures as high as 1,250 degree F. The commercially available graphite lubricant is a colloidal dispersion of billions of microscopic particles of graphite. When this is added to the crankcase of an engine, it functoins with the motor oil to decrease friction. It also penetrates efficiently into areas where oil can not reach, keeps oil from thickening, enhances compression and helps energy use and fuel economy.
