Varying the Geometry of Laser Surface Microtexturing to Enhance the Frictional Behavior of Lubricated Steel Surfaces

We experimentally investigate and theoretically interpret the effect of varying the microstructure geometry introduced by laser surface texturing (LST), on the frictional properties of interacting components. The ability to control the coefficient of friction under lubricated conditions is demonstrated. Particularly, the LST optimization of a regular pattern of microholes on steel allows to reduce friction over the entire range of sliding velocities with respect to the untextured case. Moreover, we measure the Stribeck curves on a range of sliding velocity covering the entire lubrication range, i.e. from the boundary to the hydrodynamic regime under the so called iso-viscous rigid condition. Our measurements show a friction reduction up to 50% in the hydrodynamic regime.