2. Surface properties

The choice of a surface treatment or coating should be guided primarily by the functional aspects derived from the system analysis.

The first concern is to ensure that the contact is capable of withstanding the mechanical stresses imposed on it. This concern is largely based on the cohesion and mechanical properties of the surface layers, which can be characterized by their hardness.

It is therefore necessary to determine the minimum hardness of these layers and the minimum thickness to be treated in order to avoid excessive elastic deformations and, in any case, to limit as far as possible plastic deformations which, on the one hand, lead to a loss of shape of the component, and therefore generally to its being taken out of service, and, on the other hand, significantly increase the risk of intense adhesive wear by promoting bonds by displacement...