TRIBOLOGICAL PROPERTIES OF TEXTURED TITANIUM-ALLOY SURFACE UNDER DRY-SLIDING AND WATER-LUBRICATION CONDITIONS
Guojun Deng Guojun Deng, Jialiang Guo
Abstract
A flexible and efficient solution is developed to enhance the performance and extend the service life of a Ti6-Al4-V titanium alloy.This solution combines a commercially available nanosecond laser-based metalsurface patterning technique with a self-assembled molecular-film modification.The surface of the titanium alloy is patterned with periodic dimple arrays of varying densities and depths using the laser processing.The surface morphology, roughness and chemical composition of our samples are analyzed using a scanning electron microscopy and a confocal microscopy.Moreover, the wettability of the modified titanium-alloy surface is assessed with a contact-angle meter, yielding in a maximum contact angle as large as 153.2.The coefficient of friction is measured using a tribometer and the wear mechanism is analyzed with a study of surface morphology.Under dry-sliding and water-lubrication conditions, the average coefficient of friction is reduced respectively by over 20% and 60%, when compared to the value typical for the original surface.This reduction is attributed to changed surface roughness and wettability.Our method offers a practical and efficient means of enhancing the wettability and the tribological performance of the titanium-alloy surfaces.