Tribology: The important subject for Engineering students, based on friction, wear and lubrication, used in daily life

1. Tribology
BY: Noman Nazir Channa
L-14ME45
Shakeel Ahmed Sahito
L-14ME47

2. Contents:
 Introduction To Tribology
 History Of Tribology
 Importance Of Tribology
 Applications

3. Introduction
 Tribology is derived from the Greek word “Tribos”. Means Rubbing.
 Tribology is a science that deals with friction, lubrication and wear in all
contacting pairs.
TRIBOLOGYTRIANGLE

4. Friction
 Friction is a force that is created whenever two surfaces move or try to move
across each other.
 Friction always opposes the motion or attempted motion of one surface
across another surface.

5. Wear:
 It’s the removal of material from a
solid surface by the action of
another surface.

6. Lubrication:
 Lubrication helps in reducing friction.

7. Helps in reducing …
 Wear  Removes Heat

8. Some Common Examples:
Gears
 The wear generally occurs due to
excessive contact stress.
 Having the knowledge about
stresses can helps in reducing
wear.

9. Cam Shaft
 Cams 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

10. History Of Tribology
 Historically, Leonardo da Vinci (1452–1519) was the first to say two laws
of friction (it was this connection that gave the name to the Leonardo 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 da Vinci's findings remained unpublished in his notebooks.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.

11. Continued …
 Guillaume Amontons rediscovered the classic rules (1699).
 They were further developed by Charles-Augustin de Coulomb (1785).
 Charles Hatchett (1760–1820) carried out the first reliable test on frictional wear
using a simple reciprocating machine to evaluate wear on gold coins.

12. New Areas Of Tribology
 Since the 1990s, new areas of tribology have emerged, including the Nano
tribology, bio tribology, and green 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, biomimetic tribology).

13. Importance Of Tribology:
Would Life Be Possible Without Tribology ?????

14. Yes, That’s tribology Even :P

15. Applications Of Tribology:
 Where tribology is applied ????
 Maintaining Machine Parts
 Gears
 Bearings
 Cams etc

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

18. Bearings

19. Cam
 Cams are used to convert rotary motion into reciprocating motion.