Mechanism of Wear

In adhesive wear, also called as, galling, scoring, seizing and scuffing, tiny projections produce friction by mechanical interference, along with the relative motion of contacting surfaces increasing resistance to further movement. The interlocked particles are deformed If the driving force is enough to maintain movement. If they are of a brittle material, they might be torn off. This leads to the conclusion that wear resistance shall be develop by preventing metal-to-metal contact by enhancing the hardness to resist primary indentation, increasing the toughness to resist tearing out of metallic particles and enhancing the surface smoothness to remove the projections.

Abrasive wear occurs while hard particles slide or roll under pressure across a surface, or when a hard surface rubs across another surface. The abrading particles from the harder object & tend to scratch the softer material. These hard particles might also penetrate the softer metal & cause the tearing off of metallic particles.

The ease with which the deformed metal might be torn off based upon the toughness. Thus, hardness & toughness, the similar properties that influence adhesive wear, also find out abrasive wear. Of these two factors, hardness is possibly more important one.