Wear induced changes in surface topography during running-in of rolling-sliding contacts

Running-in occurs in rolling-sliding contacts under mixed-friction conditions and typically involves asperity smoothing through mild wear plastic deformation. To improve the prediction of service life or friction rolling-element bearings conditions, knowledge surface topography changes during running-in their dependence on operating condition is an important prerequisite. Therefore, this study aims to describe mechanisms due wear, one variables, slip. AISI 52100 steel specimens were tested a mini traction machine (MTM) instrumented with contact potential measurement presence PAO base oil, mixed lubrication regime. A novel method pre post-test relocation 3-D optical profilometry scanning electron microscopy (SEM) was implemented. Rolling-sliding tests performed effect slide-roll ratio running-in. Additional conducted track period. The results exhibit rapid nature how most occur first few load cycles. Surface transitions such as removal increase load-bearing area asperities slip, flow material from peaks into adjacent valleys are shown at high magnification. measurements show that reduction depth adds roughness, thus accurately identifying mechanism, redressing consensus roughness mainly deformation diminishing height peaks, which true for ideal alone.