Combining laser biomimetic surface microtextured and PTFE solid lubricant for improved friction property of Ti6Al4V

Titanium alloys have limited applications due to their poor friction performance. Inspired by the scale structures on biological surfaces in nature, laser surface texturing technology was employed to fabricate diamond-shaped biomimetic micro-textures with different angles and area densities on the surface of titanium alloy (Ti6Al4V). The coupling effect of scale-like biomimetic micro-textures and polytetrafluoroethylene (PTFE) coatings on the frictional properties of Ti6Al4V were explored. A comparison was made between PTFE-coated untextured and textured samples, and the tribological properties of PTFE coatings on surfaces with different texture angles and densities were investigated. The contact stress distribution between the friction pairs was simulated using ANSYS finite element analysis software. We found that the combination of textured surfaces and PTFE coatings effectively reduced the friction coefficient of Ti6Al4V and enhanced the load-bearing capacity of the PTFE coating. This is because the diamond-shaped biomimetic micro-textures facilitate the continuous supply of PTFE lubricant to the Ti6Al4V friction surface, providing long-lasting lubrication and reducing friction during the tribological process. The textured samples with a 90° angle and an areal density of 30% exhibited the best friction-reducing properties, with the average friction coefficient decreasing by 71.42% under a 10 N load and 73.50% under a 20 N load. This study employed a combination of experiments and simulations to validate the effects of texture angle and areal density on the coupled PTFE coating, providing guidance for the optimization design of textured titanium alloys surfaces with solid lubricants.