Tribology – Engineering Of Interactive Surfaces

By Author: Vishal Khosla
Total Articles: 19
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Tribology factors in aspects such as contact surfaces, lubricant application system, design, material, surrounding environment and operating conditions. It is inherent to several engineering disciplines. The application of Tribology reduces the wear of materials and increases service life of machinery.

Tribology is the engineering of interactive surfaces in relative motion, with the objective of reducing friction and wear to conserve energy, increasing productivity, achieving fast and precise movements and reducing maintenance.

Tribology studies friction between two moving bodies, the natural effect of wear and friction and lubrication as a means to avoid wear. The prediction of wear is difficult because it is an intrinsic property of the material, but depends on the entire friction that interacts with the body. Wear analysis is important as corrosion is a major cause of machine failure.

Engineering defines friction as the resistance to movement during sliding or rolling. Two solid bodies move over each other. Level of friction depends on the characteristics of surfaces. Static and dynamic are two major ...
... categories of friction.

Wear is defined as the damage caused to the surface by removal of material from one or both solid surfaces that move against each other. It is a process in which the surface layers of a solid break or peel off. There are different types of wear, such as adhesive, abrasive, corrosive etc.

Lubrication is a means to reduce friction and thereby decrease wear. A lubricant attempts to build a thin layer of itself between rolling or sliding surfaces and prevents surface to surface contact, thereby doing what it is meant to. The lubricant is a very general term and it can be in any physical state – liquid, solid, gaseous or semi-solid.

Tribology takes into account aspects such as design, material, contact surfaces, lubricant application system, surrounding environment and operating conditions. It impacts virtually all moving parts such as bearings, seals, piston rings, clutches, brakes, gears and cams. It helps solve problems in machinery, equipment and industrial processes such as electric and combustion engines, turbines, compressors, extrusion, rolling, casting, forging, cutting processes, magnetic storage elements and even joint replacements (human body).

Tribology is inherent to several engineering disciplines. The application of Tribology reduces the wear of materials, increases service life of tools and machinery, saves natural resources and energy, protects environment and helps in economic savings as well.

Tribometer is an instrument meant for measuring tribological quantities such as friction force, coefficient of friction and wear volume. Basic tribometer has a hanging mass and a resting mass on a horizontal surface, connected to each other through a pulley and a string. µ, the coefficient of friction is derived by increasing the hanging mass until the resting mass begins to slide. In test applications that use tribometer, wear is measured by comparing the surfaces of test specimens before and after testing.

A heavy duty tribometer can go upto 5000N force/load. For industries like oil, coating, lubricant, etc. tribometer is a power tool. It can deal with extreme tempratures. Test heads could be rotary, fretting, block on ring, fast reciprocating, arc, linear, etc. Nano and micro tribometers can negotiate the load of nN to 1000mN /250N. These can precisely control loads from nN. They can work with several add-on techniques like AFM, laser profiler, Acoustic emission, Raman microscope, etc.

Author of this article is associated with Rtec Instruments, a California based company that deals in high temperature tribometer, 3D profilometer, atomic force microscope and other instruments.