Wear Theory. Bidimensionnal Models

Relative movement between two solids generates two inseparable and irreversible phenomena: friction, i.e. mechanical resistance to this relative movement, and wear, i.e. the loss of material from the opposing bodies. Unlike friction, which has both positive and negative consequences, the wear and tear of rubbing parts in mechanisms and manufacturing tools has only negative aspects and must be minimized. However, contact involves two antagonists, and it is often desirable to concentrate wear phenomena, a priori unavoidable, on one of the two parts, the easier and less costly to change. It should also be noted that the aim of abrasive machining processes is to remove material from the machined part at the highest possible speed, while minimizing the damage and wear caused by the abrasive agents.

Since wear needs to be taken into account in the design of machines and manufacturing operations, the aim of this article is to provide models for predicting the wear rate of rubbing parts and thus controlling their service life. Preston-Archard's law has been presented and discussed at [TRI500] . It describes the effect of normal force P and sliding length L on wear debris volume V, with the aid of wear speed k. Within a certain range of validity, when thermal effects remain limited, a rubbing contact can be characterized by its wear speed: k = V/(PL). The article [TRI501] describes the various wear mechanisms of mechanical, thermomechanical and physico-chemical origin. The article [TRI502] presents the modeling of wear by extrusion of peripheral burrs and the elementary approach to abrasion using force, material and energy balance equations and the results of scratch tests. It specifies the wear rate k or wear coefficient k* = kHV for ductile materials, where HV denotes the Vickers hardness of the part under consideration, bearing in mind that a ductile material can by definition undergo large deformations before fracture. The present article continues the mechanical...