A Device Enhancement for the Dry Sliding Friction Coefficient Measurement Between Steel 1080 and VascoMax with Respect to Surface Roughness Changes

摘要

An enhancement of an existing tribometer device developed by Philippon et al. (Wear 257:777-784, 2004) is presented in this work. This experimental device is made up of a dynamometer ring and a specific load sensor allowing to apply an apparent normal force on specimens and to measure frictional forces respectively. A set of strain gauges are added to the upgraded dynamometer ring in this new configuration. The apparent normal force can be recorded accurately during the sliding process. The setup is adapted on a hydraulic testing machine to carry out steel-on-steel dry sliding tests. The first set of standard Steel on standard Steel specimens (XC 38 French standard steel) with two apparent normal pressures are imposed (8 and 80 MPa) as the range of sliding velocities varies from 0.12 to 3.72 m/s for the same contact conditions. The main set of experiments with low sliding velocities (varying from 0 to 3 m/s) for the Steel 1080 on Steel VascoMax are performed in the same tested setup. The recordings of normal and tangential forces leading to the friction coefficient determination are discussed. The values of dry friction coefficient μ according to the experimental parameters are in good agreement with those observed in the literature. Using this new configuration, the effects of the sliding velocity on the surface roughness changes and on the dry fiction coefficient are also investigated. Additionally the surface roughness changes are also investigated. Performing the scans with use of the scanning electron microscope in particular locations of the specimens show the roughness decrease and reveal the occurrence of the wear phenomenon. Moreover, very interesting relations between wear and sliding velocity are observed.