The observation of individual asperity interactions in lubricated point contact

The elemental interactions between asperities of ball and flat surfaces in contact are described by considering these factors: (a) the influence of lubricant supply and distribution around the test balls on the kinematics of ball motion and surface velocities; (b) the microgeometry statistics of the contacting surfaces, defining the size, shape and distribution of individual asperities; (c) the (partial) elastohydrodynamic film formed in the Hertz contact area as it influences the average spacing between the contacting surfaces. By joint operation of these factors, individual asperity interactions take place and were observed by way of their effects on friction and their electrical conductivity behavior. On the basis of the observations, a tentative model of the asperity interactions is suggested.