4. Surface treatments

Surface treatments consist in improving the surface properties of components by acting on their surface layers. Depending on how these layers are modified, three types of surface treatment can be defined:

• thermochemical treatments, which involve modifying the existing surface to create a protective film or to bring about structural changes;

• electrolytic treatments, which generally consist of creating a protective film by electrochemical reaction with the surface;

• mechanical or thermomechanical treatments, which involve modifying the surface layers through the action of mechanical stress, to which heat can be added.

From a tribological point of view, these treatments enable us to obtain surface layers that can limit the risk of adhesion,...