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

Ralf Hellmann,Frederick Kleinwort,Peter Simon,Cemal Esen,Stefan Rung,Jan-Hendrik Klein-Wiele,Kevin Bokan,Simon Schwarz

doi:10.3390/lubricants7050043

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.

Highlights

Laser surface texturing enables a precise and reliable method to modify surface properties and provides new ways for the design and fabrication of novel surface functionality towards smart surfaces.In this wide field of surface engineering, the controllable modification of friction and wear is of high interest
Regular ablation processes using short and ultrashort laser pulses are capable of generating meso- to micro-structures with spatial feature size limitation of the applied laser spot size, typically several tens of micrometers
Laser-Induced Periodic Surface Structures (LIPSS) are categorized into 3 groups, namely low spatial frequency LIPSS (LSFL), high spatial frequency LIPSS (HSFL), and cone-like protrusions (CLP) [8]

Summary

Introduction

Laser surface texturing enables a precise and reliable method to modify surface properties and provides new ways for the design and fabrication of novel surface functionality towards smart surfaces. In this wide field of surface engineering, the controllable modification of friction and wear is of high interest. While laser-based surface functionalization has already been intensively studied during the last decade, femtosecond laser technology has recently expedited surface structuring on different length scales to advance tribological properties [2,3,4,5,6,7]. On the other hand, advanced processing techniques can fabricate surface texturing patterns with feature sizes magnitudes below the applied laser spot size

Methods

Results

Conclusion