100 Tribology is the science and engineering of interacting surfaces in relative motion. It consists of the study and application of the principles of friction, lubrication and wear. Tribology is a branch of mechanical engineering.
The tribological interactions of a solid surface’s exposed face with interfacing supplies and environment may result in loss of material from the surface. The procedure leading to loss of material is known as “put on”. Key types of put on incorporate abrasion, friction (adhesion and cohesion), erosion, and corrosion. Wear can be minimized by modifying the surface properties of solids by one or more of “surface engineering” processes (also named surface finishing) or by use of lubricants (for frictional or adhesive wear).
Lubrication is the approach, or technique employed to reduce wear of one or each surfaces in close proximity, and moving relative to each another, by interposing a substance referred to as lubricant among the surfaces to carry or to aid carry the load (stress generated) amongst the opposing surfaces. The interposed lubricant film can be a strong, a solid/liquid dispersion, a liquid, a liquid-liquid dispersion (greases) or exceptionally a gas.
Adequate lubrication makes it possible for smooth continuous operation of equipment, with only mild put on, and with out excessive stresses or seizures at bearings. When lubrication breaks down, metal or other elements can rub destructively over each other, causing destructive damage, heat, and failure.
Usually lubricants include 90% base oil (most usually petroleum fractions, known as mineral oils) and much less than ten% additives. Vegetable oils or synthetic liquids such as hydrogenated polyolefins, esters, silicones, fluorocarbons and many other people are at times employed as base oils. Additives deliver reduced friction and put on, increased viscosity, improved viscosity index, resistance to corrosion and oxidation, aging or contamination, etc.
Greases are utilized exactly where a mechanism can only be lubricated infrequently and where a lubricating oil would not stay in position. They also act as sealants to prevent ingress of water and incompressible materials. Grease-lubricated bearings have higher frictional characteristics due to their high viscosity.
Lubrication is essential for right operation of mechanical systems pistons, pumps, cams, bearings, turbines, cutting tools and so forth exactly where without lubrication the pressure in between the surfaces in close proximity would create enough heat for fast surface harm which in a coarsened situation may possibly actually weld the surfaces together, causing seizure.