The Influence of Surface Roughness on Friction and Wear in Boundary Lubrication

Abstract

Assuming that the radii of curvature at tips of spherical asperities are distributed, analyses of friction and wear in boundary lubrication are carried out by considering the ploughing action of hard asperities. To check the theory, the coefficient of friction and the wear rate of an annular end surface of a mild-steel cylinder rubbed by that of a hardened-steel cylinder are measured for various degrees of roughness from 0.038 to 0.568 μ Rmax under lubricated conditions. The general trend of the experimental results is in agreement with the calculations. The results also indicate that the repetition of the ploughing action of hard asperities forms the wear particles.