Laser hexagonal texture on surface of Ti6Al4V for the improvement of fluid spreadability and tribological properties

Abstract

The joint capsule removal after artificial joint replacement surgery have led to improper lubrication, causing the pair to wear out quickly and reducing the joint lifespan. In this paper, laser processing and chemical corrosion were used to prepare a hexagonal convex texture on the surface of titanium alloy (Ti6Al4V). After etching and laser polishing, SEM images indicated the presence of secondary micro-nano textures in the grooves around the hexagonal texture, and the formation of anatase oxides on the surface, resulting in an increase of the surface energy and a very small contact angle (CA). The surfaces’ CA increases with the texture ratio, and the surface is super-hydrophilic when the texture ratio is less than 0.84. Furthermore, the effect of texture parameters and directions are studied by using UHMWPE and Ti6Al4V as friction pairs and simulated body fluid as lubricant. The COF is 0.068 with 0.84 area ratio, which is 51.4% lower than the original surface. The wear rate of UHMWPE on the textured surface decreases by 74.5% after two hours of tribological testing. In addition, high speed camera images and calculation results proved that creating grooves can promote fluid distribution on the textured surface. The surface texture on titanium alloy results in a significant COF and wear reduction, extending the service life of artificial joints.