Kinetics of formation of boundary lubricating film in zone of facing–tool contact under metal cutting

Abstract

Tribological processes that occur in the zone of the facing–tool contact can be satisfactorily described using a three-zone model in which zones of adhesion, seizure, and friction are distinguished. An expression that relates the coefficient of friction under cutting to the distribution of the zones of friction over the surface of contact has been obtained, causes for the origination of the zone of adhesion have been analyzed, and the shear strength of boundary films has been estimated. A model that describes the kinetics of the formation of a boundary lubricating film in the zone of friction with account for the dimensions and the shape of surfactant molecules, as well as the concentration of surfactants, has been developed. The results of the calculations have shown good agreement with the experimental data.