Derivation of coefficient of friction at high sliding speeds from energy conservation over the frictional interface

In this study, a model is proposed which describes the collisions between the asperities of two contact bodies and the heat transfer among them in case of the high speed sliding. Based on the conservation between the frictional work and the generated heat over the frictional interface, formulas for the evaluation of the coefficient of friction are then derived. The coefficient of friction can be directly calculated from these formulas when the sliding condition and the material constants of the contact bodies are known. The present formulas for coefficients of friction not only improve the accuracy of a previous formula derived from Blok’s flash temperature theory but also eliminate the trouble to determine a constant from experimental datum. Moreover, it is shown that the present formulas can highlight some features of the friction at high sliding speeds and provide a unitary explanation to some experimental observations of the friction.