Laser microstructuring of surfaces for improving their tribological performance

The controlled laser microstructuring of solid surfaces improves their wear properties: microholes induced on a friction surface can act like lubricant reservoirs and as traps for debris particles. In generating such microstructures, the laser has the advantage of its great versatility, since it can be used in various environments and it can be adapted to a wide range of desired structures. In this work metallic surfaces where precisely and reproducibly patterned on a micrometer scale by an industrial, Q-switch-operated Nd:YAG laser. The duration of the pulses was 100 ns FWHM. For laser ablation in this pulse length range local melting and vaporing govern the mechanisms of materials expulsion and the melt ejection occurs through the vapor pressure gradient, yielding the formation of resolidified droplets and rims on the target surface.