Possibilities of Dry and Lubricated Friction Modification Enabled by Different Ultrashort Laser-Based Surface Structuring Methods

Abstract

In this contribution we report on the possibilities of dry and lubricated friction modification introduced by different laser surface texturing methods. We compare the potential of Laser-Induced Periodic Surface Structures and Laser Beam Interference Ablation on 100Cr6 steel in a linear reciprocating ball-on-disc configuration using 100Cr6 steel and tungsten carbide balls with load forces between 50 mN and 1000 mN. For dry friction, we find a possibility to reduce the coefficient of friction and we observe a pronounced direction dependency for surfaces fabricated by Laser Beam Interference Ablation. Furthermore, Laser-Induced Periodic Surface Structures result in a load-dependent friction reduction for lubricated linear reciprocating movements. This work helps to identify the modification behaviour of laser generated micro structures with feature sizes of approximately 1 µm and reveals new possibilities for surface engineering.

Quo Vadis LIPSS?—Recent and Future Trends on Laser-Induced Periodic Surface Structures

“…Another method for producing line grating like periodic surface structures relies on direct laser interference patterning (DLIP) by superimposing two focused laser beams at the sample surface. Figure 4 compares the processing of LIPSS by using a Galvanometer scanner and an f-Theta lens ( Figure 4 a) with the more complex DLIP setup ( Figure 4 b), where an additional grating interferometer is employed to realize the two-beam interference here [ 47 ].…”

“…DLIP structures can have significantly larger modulation depths and higher regularities of periodic surface patterns, as demonstrated in Figure 6 . The larger modulation depths may be beneficial for the tribological performance of the laser-structured surfaces [ 47 ] as they allow to better confine some lubricant in the tribological contact area [ 49 ].…”

“…( b ) Setup for direct laser interference patterning (DLIP) processing. Abbreviations: HWP: half-wave plate; THG: third harmonic generator; BET: beam expanding telescope; reprinted from Rung et al [ 47 ], Possibilities of Dry and Lubricated Friction Modification Enabled by Different Ultrashort Laser-Based Surface Structuring Methods, Lubricants, 2019 , 7, 43. Copyright 2019 under Creative Commons BY 4.0 license.…”

“…Structures processed by DLIP reveal a larger regularity in the SEM micrograph ( c ) and larger depth modulations in the AFM cross-section ( d ). Adapted from Rung et al [ 47 ], Possibilities of Dry and Lubricated Friction Modification Enabled by Different Ultrashort Laser-Based Surface Structuring Methods, Lubricants , 2019 , 7, 43. Copyright 2019 under Creative Commons BY 4.0 license.…”

Editorial: Special Issue “Laser-Induced Periodic Surface Nano- and Microstructures for Tribological Applications”

“…Rung et al [5] compared the tribological performance of dry and oil-lubricated periodic surface structures generated on steel surfaces either via self-organization (LIPSS) or by DLIP. Although structures with similar periodicity (0.9-1.5 µm) were produced, their tribological behaviour in a linear reciprocating ball-on-disc configuration was different [attributed to the different modulation depths of either~0.2 µm (LIPSS) or~1.5 µm (DLIP)].…”