Reducing friction and wear is essential to build efficient systems with lower energy consumption and longer life-time. Surface texturing is one of the methods to improve the tribological properties of contacting surfaces, especially in the oil-lubricated systems. Several experimental works described in literature showed that micro-texturing can reduce the friction by acting as micro-reservoirs for lubricant, micro-hydrodynamic bearings and/or micro-traps for wear debris in sliding surfaces. Despite all the efforts in this filed, there is still lack of knowledge about fundamental aspects involved in the improvement of tribological performance, especially for those mechanical parts sliding under the boundary lubrication regime, and more specifically the effect of textures on wear mechanism and scuffing resistivity. The aim of this study was to investigate the effect of surface texturing on frictional and wear behavior of cast iron sliding under the starved lubrication conditions and failed by scuffing.
In order to produce micro-textures on cast iron surfaces, a pulsed nanosecond laser was used. Reciprocal lubricated sliding tests were carried out for the cast iron-steel tribo-pair at a pressure of 24 MPa and a frequency of 6 Hz. Frictional and wear behavior of cast iron with different micro-textures were characterized and compared with un-textured one. We proved that micro-textures can increase the lifetime of our tribo-system. It was also discovered that surface texturing can affect not only the friction behavior but also the wear and so the failure mechanisms of sliding surfaces. We showed that surfaces with certain combinations of micro-textures do not fail by scuffing but are subjected to another wear mechanism from which they can be recovered. Finally, we found out that the main parameter defining the wear and failure mechanisms is the distance between the micro-textures.