Surface topography and friction coefficient evolution during sliding wear in a mixed lubricated rolling-sliding contact

Abstract

Wear is a common phenomenon which most mechanical components suffer from. Available studies are mainly focused on the wear performance after contact pairs operate for a period of time. The studies on evolution of surface topography and friction coefficient resulting from the wear process under mixed lubrication conditions are still limited. Further study of this issue may have a significant influence on wear reduction and lubricating performance improvement. In the present study, surface topography and friction coefficient evolution during sliding wear in a mixed lubricated rolling-sliding contact are investigated by the method based on the numerical approach developed by Zhu.et al. [1]. The numerical results are compared with experiment results to demonstrate the efficiency and accuracy of the present wear model. The evolutions of wear track, root mean square (RMS) roughness, and friction coefficient are observed systematically during wear process. The influences of load, slide-to-roll ratio and surface orientation on these characteristics are studied as well. The simulation results are in good agreement with experimental observations. The wear track is quite different from the one under dry contact, due to the effect of oil and the contact deformation. The friction coefficient drops rapidly at first and then it keeps stable with small fluctuations with respect to wear evolution. It indicates that load and slide-to-roll ratio have a remarkable impact on wear rate, though the effect of surface topography is limited. Further, the results show that the RMS roughness deceases slightly at first and then it increases gradually during the wear process. • A point wear model of real, engineering rough surfaces has been introduced in this paper. • In the early running-in process, the wear tracks on both sides are deeper than in the middle, which is different from that under dry contact. • In the running-in process, the friction coefficient drops rapidly first and then keeps stable with small fluctuations. • Increasing load and slide-to-roll ratio can increase the wear rate.