Tribological performance of laser-textured steel surfaces in unidirectional sliding line-contact (block-on-ring)

Abstract

The following theoretical and experimental work presents a study on the influence of texture parameters on the tribological performance of dimpled steel surfaces. Different texture parameters were selected through hydrodynamic lubrication modeling based on the two-dimensional Reynolds equation and literature search. For the experimental work, microscopic spherical cavities (i.e., dimples) were created by laser on 25 mm steel discs. The textured specimens were tested in a unidirectional sliding line-contact block-on-ring set-up at different rotational speeds. The experiments showed that the area-density-ratio, dimple-depth, and dimple-diameter can significantly affect the tribological performance of steel surfaces. Specimens containing dimples with lower depth, lower area-density-ratio, and smaller diameters, exhibited significant improvements over a smooth steel surface. The most remarkable achievement was a 28.6% friction reduction at 20 RPM and an overall improvement of 13% considering all speeds.