Tribology Course Seminar Course: Machine Design II By: Kavya M Bhat Devender Jain Deepak T BVBCET 11/17/2018

Contents Introduction History Need for tribology Wear Friction Lubrication Tribometer Conclusion References BVBCET 11/17/2018

Tribology It is derived from the Greek word “tribo” which means rubbing or sliding. Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication and wear. BVBCET 11/17/2018

History The term Tribology was coined, in 1966, by Professor Peter Jost and the working party which had been set up by the UK government of the day, to address the steep increase in machinery failures from wear and associated causes which resulted in heavy financial losses. The purpose of the working party was to “investigate the present state of lubrication education and research in this country and to give an opinion on the needs of industry thereof”. BVBCET 11/17/2018

using the correct lubricant The main conclusion of the Jost Committee, as it is now widely referred to, was that significant financial savings were achievable by the correct application of Tribology. Fairly simple actions such as:- using the correct lubricant servicing machines in a timely fashion and in accordance with the machine manufacturer’s instructions BVBCET 11/17/2018

Need for Tribology To minimize and eliminate losses. Greater efficiency, performance, fewer breakdowns & savings. Study various losses and analysis of losses. Reduce losses by introducing a layer of lubrication. Atomic and molecular observations on sliding surfaces. BVBCET 11/17/2018

Wear In materials science, wear is erosion or sideways displacement of material from its "derivative" and original position on a solid surface performed by the action of another surface. Wear is related to interactions between surfaces and more specifically the removal and deformation of material on a surface as a result of mechanical action of the opposite surface BVBCET 11/17/2018

Types of Wear Abrasion wear- when a hard rough surface slides over a softer surface. Adhesive wear- be found between surfaces during frictional contact Cavitation wear- caused by the localized impact of fluid against a surface or fast flowing fluids. Erosion wear- the impact of particles of solid or liquid against the surface of an object. BVBCET 11/17/2018

Wear can be minimized by modifying the surface properties of solids by one or more of "surface engineering" processes (also called surface finishing) or by use of lubricants (for frictional or adhesive wear). Engineered surfaces extend the working life of both original and recycled and resurfaced equipments, thus saving large sums of money and leading to conservation of material, energy and the environment. Methodologies to minimize wear include systematic approaches to diagnose the wear and to prescribe appropriate solutions. BVBCET 11/17/2018

Important methods include: Terotechnology Horst Czichos's systems approach. Nano-tribology BVBCET 11/17/2018

Friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types: Dry friction Fluid friction Lubricated friction BVBCET 11/17/2018

Lubrication Thin layers of gas, liquid and solid interposed between two surface is called lubrication. Layers of material separate contacting solid bodies. Main aim of lubrication is to reduce the wear and friction. BVBCET 11/17/2018

Types of lubrication Hydrodynamic lubrication- Analysis of Gaseous or liquid films is usually termed Solid lubrication- Lubrication by solids is termed, Ex. Graphite Elastohydrodynamic lubrication- Physical interaction between the contacting Bodies and the liquid lubricant. Hydrostatic lubrication- Complete separation of sliding surfaces with negligible wear and very low friction. Applied to aerostatic and hybrid bearings. BVBCET 11/17/2018

Tribometer A tribometer is an instrument that measures tribological quantities, such as coefficient of friction, friction force, and wear volume, between two surfaces in contact. It was invented by the 18th century Dutch scientist Musschenbroek BVBCET 11/17/2018

Conclusion The study of Tribology is important so as to increase the efficiency of any machine components or parts which has relative motion between them due to which friction and wear occurs in the machine or component. BVBCET 11/17/2018

References http://en.wikipedia.org/wiki/Tribology http://en.wikipedia.org/wiki/Friction http://en.wikipedia.org/wiki/Tribometer http://en.wikipedia.org/wiki/Wear http://www.nanovea.com/Tribometers.html BVBCET 11/17/2018