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

Abstract

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.

Validation of the Klepaczko–Malinowski model for friction correction and recommendations on Split Hopkinson Pressure Bar

“…This value is usual for a surface quality reached after classical machining even if a lubricant is used [21]. In our case a constant value is used not depending of the sliding velocity and the roughness change as discussed in [22] A good agreement of all curves taken from different specimens is shown in Fig. 6 introducing the friction correction to the original curves (Fig.…”

“…The model considering a cylinder loading dynamically and deformed uniformly is based on an energetic approach [20][21][22][23][24][25][26][27]. However, it includes the energies due to radial and longitudinal inertia coupling with it due to friction caused by the overstress level.…”

On the Taylor–Quinney coefficient in dynamically phase transforming materials. Application to 304 stainless steel

“…The specimen has been meshed using elements whose aspect ratio was 1:1 (¼ 50 Â 50 lm 2 ). The boundary conditions have been set using rigid surfaces which interact with the specimen through a penalty-type contact with a Coulomb friction coefficient l f ¼ 0:1, a value commonly adopted for dynamic contact between steel-steel pairs (Hartley et al, 2007;Philippon et al, 2011). The viscous method available in ABAQUS/Explicit has been used in both tension and compression models to prevent hourglass deformation modes; the scale factor used for all hourglass stiffnesses was chosen equal to one.…”

A split Hopkinson pressure bar device to carry out confined friction tests under high pressures

“…Numerical simulations display that the "low-velocity impacts" lead to contact pressures reaching 100 MPa and sliding velocities reaching 10 m/s at the interfaces. Few 3 tribometers satisfy these requirements: tribometer with explosively-driven friction [8], targetprojectile assembly with oblique impact [9], Hopkinson torsion bars [10], dynamometrical ring with parallelepipedic specimen launched by a gas gun or an hydraulic machine [11] and the friction of a pin on a revolving disc [12], [13]. With these classical tribometers, mainly used on metals and ceramics, the friction samples are tested in simple compression and this configuration is unfortunately not adapted to our situation, as explained above.…”