Experimental and numerical studies of positive texture effect on friction reduction of sliding contact under mixed lubrication

Textured surfaces have been remarkable in improving the frictional performance of sliding contacts, particularly at instances such as boundary or mixed lubrication regimes. This article reports the results of an experimental and numerical study carried out by introducing surface textures in the form of protrusions to investigate its effects on friction performance under a mixed lubrication regime. The surface textures produced by the chemical etching process are tested on the pin on disc test rig by varying area density and height of the texture. In numerical simulation, the modified Reynolds equation (Patir-Cheng flow model) and asperity contact model (Greenwood-Tripp model) are solved for hydrodynamic and asperity pressures, respectively. The results indicate that the experimental measurements are qualitatively in good agreement with numerical predictions. Furthermore, the simulations are performed for different texture shapes by varying texture area density, height, and sliding velocity. The results depict that a maximum friction reduction of 87% with elliptical textures compared to the un-textured case.

Automated summary

Textured surfaces show remarkable improvement in frictional performance, especially in boundary or mixed lubrication regimes. Experimental and numerical studies have demonstrated that introducing surface textures in the form of protrusions can lead to up to 87% friction reduction compared to un-textured surfaces, with results qualitatively agreeing between experiments and simulations. Varying texture shapes, area density, height, and sliding velocity all have significant impacts on friction performance.