<p style="text-align: justify">a large number of energies are wasted between mechanical components during the tribological process. Recently, surface texturing technology has gradually gained attention in the tribology community to reduce energy consumption. Especially, laser micro-texturing treatment has been proved as an efficient way to reduce wear and friction and increase the lubricating ability of metal alloys. Meanwhile, ionic liquids also show great potential as novel lubricant additives to increase the durability of contacting components and decrease material loss during the tribological process. Particularly, ionic liquids that are halogen-free and easy to be synthesized are needed urgently by considering the strict environmental regulations and their potential industrial applications. Therefore, an eco-friendly protic ionic liquid, 2-hydroxyethylammonium 2-ethylhexanoate, was designed and synthesized in this project that was used as an additive to the base oil - polyalphaolefin 40. This study investigated the influence of the laser micro texturing surfaces on the tribological performance of titanium alloy Ti6Al4V under different lubricant conditions.</p><p style="text-align: justify">In this research, two sets of dimple-textured surfaces created by different laser parameters, various energy density, and area density, were fabricated on Ti6Al4V. Two types of lubricants, polyalphaolefin 40 and its mixture into which 2-hydroxyethylammonium 2-ethylhexanoate was added with a concentration of 1 wt. %, were used during the sliding tests. First, the geometrical properties of laser micro-textures on the surfaces were characterized. The wetting behaviors of different lubricants on textured surfaces were then examined based on contact angle measurement. All the frictional tests under ceramic-Ti6Al4V contact were carried out on the ball-on-flat reciprocating tribometer under room temperature with a mean Hertz contact pressure of 1.54 GPa and maximum Hertz contact pressure of 2.3 GPa. Lastly, the surface morphology of the wear tracks on Ti6Al4V and tungsten carbide balls and their wear mechanisms were evaluated by using the optical microscope, 3D profilometer, scanning electron microscope, and energy-dispersive X-ray spectroscopy. The sliding test results exhibit the laser micro-textures have a positive effect on improving the tribological performance of Ti6Al4V. This phenomenon may be caused by the improvement of the lubricant retention ability of textured surfaces when compared to the untextured surface. Moreover, the plastic deformation along the border of wear tracks has also been decreased significantly with having laser micro-texture on Ti6Al4V surfaces. Meanwhile, it is also noted that the use of 2-hydroxyethylammonium 2-ethylhexanoate as the lubricant additive to polyalphaolefin 40 may facilitate the formation of the tribo-layer, which enhances the tribological properties of laser micro-texturing Ti6Al4V surfaces.</p>

The Evaluation of Tribological Performance of Laser Micro-Texturing Ti6Al4V Under Lubrication With Protic Ionic Liquid

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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