Tribology 101

Tribology is a study on friction, wear, adhesion and scratch resistance of moving interferences in contact. In other words, it is a study on movement of surface in contact with one another and the surroundings. The study also involve dissipation of energy (friction induces heat energy and etc.). Wear, being one of the sub-content of tribology is a study of useful life of a material or a part component of a machine. It is given by the equation:


Usp = Vloss / (FxD)

Usp = wear rate
Vloss = volumetric loss
F = force applied
D = total sliding distance

There are 4 types of wear, namely:
a)Abrasive wear
-Due to presence of hard/sharp particles between contacting surface (moving)

b)Adhesive wear
-Due to unsuitable lubrication or lubricant ran dry between moving surfaces in contact

c)Surface fatigue
-Due to repeated mechanical stress

d)Tribo-oxidation
-Tribological sliding causes chemical reaction, increase of temperature of contacting surfaces and oxidation

From the 4 types of wear mentioned above, wear is a study of useful life of components. The useful life of components here are components of a machine that experiences friction during operation. Friction causes loss of solid material on the contacting surface and this will reduces the integrity of the material. Thus, this is why friction and wear are mentioned concurrently since all 4 types of wear are caused by frictional problems.