P. Pallav, PhD

Depending on the materials of the contacting surfaces this type of wear can occur at the same places as abrasive wear. Adhesive wear is related to high shear stresses caused by friction.

The figure shows how, with relatively little penetration, a particle is torn from the substrate beneath the sphere, in contrast to the ploughing action in abrasion, where particles are created in front of the sphere. 

d/R < 10-4	10-4 < d/R < 0.1	d/R > 0.1
If the penetration depth ( d/R) is very small (left) no damage is caused when the sphere moves over the surface. Up to d/R ≈ 0.1  a furrow is created. Above this value the surface layer is torn from the substrate beneath the sphere.

If cold, solid-phase welding occurs in the micro-contacts, the coefficient of friction is generally very high. High adhesive shear stresses tear platelet-shaped wear particles out of the surface(s) which may, sometimes permanently, remain attached to the antagonistic surface (material transfer), which in mild cases may reduce the wear rate and in severe cases (galling, scuffing, or even seizure) can increase the wear rate. The material should exhibit work hardening otherwise a particle as such, a hardened surface part over a less strong deeper layer, cannot be created. Under dynamic circumstances visco-elastic behavior may mimic work hardening in this respect, since in such cases the strength as well as the effective Young's moduli vary with the (local) strain rates. 
Adhesive wear is often increased by low hardness, low ductility and cleanness of the surfaces.

2a. Delamination Wear

Delamination wear bears much resemblance with the previous type. Even so much that it is not generally recognized as a separate type of wear. The difference would be that although the friction is high, cold solid-phase welding or material transfer do not occur. The also flake like wear particles do not remain attached to the antagonist.