Wear of Mechanical Contacts. Controlling Wear and Friction

In the absence of formal prescriptions and, what's more, of "catalogs" of solutions, the resolution of friction and wear problems today relies essentially on a certain number of "rules of the art" derived from general laws built up most often on the basis of feedback, cross-checking...

Despite the efforts made to formalize knowledge and know-how (modeling, databases, user guides, etc.), the information available remains indicators which, more often than not, allow us to conclude not on the choice of a solution, but on several possible options. This very common situation justifies the importance of experimentation in tribology, which is often an essential means of selecting and making the final choice of solutions.

The following are a number of design rules for use in mechanical engineering, involving most of the parameters of tribological contact: geometry, topography, lubrication, materials, etc. The proposed rules and recommendations are structured as follows:

• the first group of recommendations, relating to surface mechanical stresses, temperatures, friction coefficients and lubrication, corresponds to principles applicable to the (most frequent) situations where wear phenomena call into question the mechanical and thermal behavior of rubbing contacts;

• topography specifications are to be adapted on a case-by-case basis, depending on the context of use and, in particular, the lubrication method;

• material-specific indicators (including surface treatments) cover selection and orientation criteria in relation to the main wear modes, as well as the basic properties and areas of use of a few major families of possible solutions.

This article is the last in a series dedicated to mechanical contact wear:

• Issues and definitions [BM 5 065] ;

• Elements of tribology [BM 5 066] ;

• Wear and tear