Module 2 :
Lecture 8 : Surface Properties of Materials
 


Surface Mechanical Property: Wear Rate

Wear is defined as the removal of material from the surface of an object through contact with another surface. Thompson et al have classified wear into two major categories: wear due to mechanical interaction and due to chemical reaction. Wear due to mechanical interaction is again subdivided into five major types:


Fretting Wear, Abrasive Wear, Adhesive Wear, Delamination wear and Wear caused by Plowing


Wear is given by the following simple relationship:


W = K x S x P


Where W is the worn volume, S is the sliding distance, P is the applied force and K is the Archard Constant expressed as worn volume per unit length per unit sliding distance.

The following are the ranges of K corresponding to different mechanisms:

Fretting Wear: K = 10-6 to 10-4

Abrasive Wear: K =10-2 to 10-1

Adhesive Wear: K = 10-4

Delamination Wear and Wear due to Plowing: K = 10-4