The effect of multi-scale laser textured surface on lubrication regime

Abstract

Laser surface texturing (LST) is a surface engineering process used to improve tribological characteristics of materials by creating patterned microstructures on the mechanical contact surface. In LST technology, a pulsated laser beam is used to create arranged dimples on surface by a material ablation process, which can improve load capacity, wear resistances, lubrication lifetime, and reduce friction coefficients. In the present study, the effect of multi-scale LST on lubricant regime was investigated. A pulsed Nd:YAG laser was applied on steel (AISI 52100) to create arranged dimples. To optimize the surface texturing effect on friction, multi-scale texture dimples with some specific formula arrays were fabricated by laser ablation process by combining circles and ellipses. The tribological testing of multi-scale textured surface was performed by a flat-on-flat unidirectional tribometer under lubrication, and the results compared with that of untextured surface. Through an increase in sliding speed and dimple depth the beneficial effect of multi-scale LST performance was achieved. The multi-scale textured surface had lower friction coefficient performance than the untextured surface due to hydrodynamic lubrication effect.