Multi-Scale Surface Texturing in Tribology—Current Knowledge and Future Perspectives

Abstract

Surface texturing has been frequently used for tribological purposes in the last three decades due to its great potential to reduce friction and wear. Although biological systems advocate the use of hierarchical, multi-scale surface textures, most of the published experimental and numerical works have mainly addressed effects induced by single-scale surface textures. Therefore, it can be assumed that the potential of multi-scale surface texturing to further optimize friction and wear is underexplored. The aim of this review article is to shed some light on the current knowledge in the field of multi-scale surface textures applied to tribological systems from an experimental and numerical point of view. Initially, fabrication techniques with their respective advantages and disadvantages regarding the ability to create multi-scale surface textures are summarized. Afterwards, the existing state-of-the-art regarding experimental work performed to explore the potential, as well as the underlying effects of multi-scale textures under dry and lubricated conditions, is presented. Subsequently, numerical approaches to predict the behavior of multi-scale surface texturing under lubricated conditions are elucidated. Finally, the existing knowledge and hypotheses about the underlying driven mechanisms responsible for the improved tribological performance of multi-scale textures are summarized, and future trends in this research direction are emphasized.

Effects of Surface Modification by Means of Low-Temperature Plasma Nitriding on Wetting and Corrosion Behavior of Austenitic Stainless Steel

“…Modification of surface topography is one of the main aims of surface engineering. By producing aperiodic or periodic patterns at the micro and/or nano scale, surface roughness changes, and thus may influence wetting behavior of liquids [1][2][3][4][5][6][7][8][9][10][11], lubrication [12][13][14], friction and wear [15,16], cell adhesion and biocompatibility [17][18][19].…”

On Friction Reduction by Surface Modifications in the TEHL Cam/Tappet-Contact-Experimental and Numerical Studies

“…The total energy efficiency could be significantly increased by utilizing new technologies such as surface modifications (Holmberg and Erdemir [5]). This can be achieved, for instance, by applying amorphous carbon (DLC) coatings (Kalin et al [6], Erdemir and Donnet [7]) or discrete microtextures (Gropper et al [8], Gachot et al [9][10][11]) onto the rubbing surfaces of lubricated tribological sliding contacts. Both approaches have been intensively investigated in the literature within various theoretical and experimental studies ranging from boundary (Pettersson and Jacobson [12]), to mixed (Löffler et al [13], Borghi et al [14]), as well as full-film hydrodynamic (Etsion [15], Pawlus et al [16,17]) and elastohydrodynamic lubrication.…”

Performance and Accuracy of the Shifted Laser Surface Texturing Method

“…The textures produced often consist of periodically repeating structures (objects). LST uses pulsed lasers for the removing or moving of material by ablation or melting processes and scanning optical systems or translation and rotation stages for the movement of the laser beam on the workpiece on predefined trajectories to form the desired surface structure [1,2]. When using ultrafast lasers, LST has almost no heat-affected zone and can be applied to transparent materials as well [3].…”

“…Plasma and particle shielding effects (2) are the attenuation or reflection of the laser pulse by plasma and ablated material produced by the laser pulse or for high repetition rates by the previous laser pulse. Mao et al [13] observed different depths and shapes of craters formed by picosecond laser ablation in various gas mediums and its pressures.…”