tribology by noman nazir

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TribologyBY: Noman Nazir Channa L-14ME45

Shakeel Ahmed Sahito L-14ME47

Contents:Introduction To TribologyHistory Of TribologyImportance Of TribologyApplications

IntroductionTribology is derived from the Greek word Tribos. Means Rubbing.Tribology is a science that deals with friction, lubrication and wear in all contacting pairs.

FRICTIONLUBRICATIONWEARTRIBOLOGY TRIANGLE

FrictionFrictionis aforcethat is created whenever two surfaces move or try to move across each other.Frictionalways opposes the motion or attempted motion of one surface across another surface.

Wear:Its the removal of material from a solid surface by the action of another surface.

Lubrication:Lubrication helps in reducing friction.

Helps in reducing Wear

Removes Heat

Some Common Examples:

Gears

The wear generally occurs due to excessive contact stress.Having the knowledge about stresses can helps in reducing wear.

Cam ShaftCams are used to transmit rotary motion in reciprocating motion. Here wear is occurred on the cam surface. These components are subjected to jerks in sliding distance, which leads to form some pits(large hole) on the cam surface. Creation of pits on cam surface increases noise pollution and reduces mechanical performance. Understanding the mechanism of wear formation helps to estimate the life of component

History Of TribologyHistorically,Leonardo da Vinci(14521519) was the first to say two laws offriction(it was this connection that gave the name to theLeonardo Centre for Tribology, one of the UK's leading research centers on the subject). According to da Vinci, the frictional resistance was the same for two different objects of the same weight but making contacts over different widths and lengths. He also observed that the force needed to overcome friction doubles when the weight doubles. da Vinci's findings remained unpublished in his notebooks.Da Vinci identified the laws of friction in a notebook in 1493 and continued his studies of friction for 20 years.

Continued Guillaume Amontonsrediscovered the classic rules (1699).

They were further developed byCharles-Augustin de Coulomb(1785).

Charles Hatchett(17601820) carried out the first reliable test on frictional wear using a simple reciprocating machine to evaluate wear ongold coins.

New Areas Of TribologySince the 1990s, new areas of tribology have emerged, including theNano tribology,bio tribology, andgreen tribology. These areas study the friction, wear and lubrication at the nanoscale, in biomedical applications (e.g., human joint prosthetics, dental materials), and ecological aspects of friction, lubrication and wear (tribology of clean energy sources, green lubricants,biomimetictribology).

Importance Of Tribology:

Would Life Be Possible Without Tribology ?????

Yes, Thats tribology Even :P

Applications Of Tribology:Where tribology is applied ????

Maintaining Machine PartsGearsBearingsCams etc

Maintaining Machine Parts:Lubricate time to time so as to reduce friction and not allow wear to take place.

Bearings

CamCams are used to convert rotary motion into reciprocating motion.