Laser Com-Texture on Ti6Al4V Surface for Lubricant Transportation to Improve Tribological Properties

Abstract

Artificial joint materials often wear out due to poor lubrication, affecting their service life. A compound texture (com-texture) was prepared, to improve the spreading of lubricant at the friction interface and reduce the friction and wear of artificial joint pairs UHMWPE and Ti6Al4V. The com-texture was divided into rough and smooth parts on the surface. The rough area was a hexagonal convex texture with a texture ratio of 66%, and it was covered with a recoagulated layer left by laser processing to absorb and transport lubricant to the friction interface. The smooth area was a convex texture with a texture ratio of 85%, which was the friction contact area. The texture morphology of the rough region was characterized by SEM and laser focusing microscope. It was found that the edge of the texture was covered with recondensed mountains after laser processing and corroded micro-nano pits, which helped to prepare super-hydrophilic surfaces. Besides, the flow law of simulated body fluid (SBF) on a textured surface was explored, and the motion process was recorded by a high-speed camera. The results showed that the com-texture could transport SBF to the friction region smoothly and quickly. The friction test results indicated that the structure had improved tribological properties.