Enhancing the tribological performance of medical Ti-6Al-4V alloy by preparing micro-textures via electro-pulse assisted ultrasonic surface rolling

Ti-6Al-4V alloy is widely utilized in orthopedic implants due to its biocompatibility; however, its low hardness and poor wear resistance often lead to inflammatory wear debris and implant failure. This study introduces the Electro-pulse-assisted Ultrasonic Surface Rolling Process (EPUSRP) to engineer high-quality biomimetic microtextures for improving the biotribological property. Systematic comparisons were conducted across polished, USRP, and EPUSRP-processed samples under dry and simulated body fluid (SBF) conditions. The findings demonstrate that EPUSRP exploits the synergistic effect of electroplasticity and ultrasonic impacts to induce intensive surface plastic deformation, resulting in the formation of a dense, gradient nanostructured hardened zone. The surface microhardness reached 480.58 HV, approximately 30% higher than the original substrate. Tribological testing demonstrates that the optimized microtextures effectively trap debris within grooves, significantly suppressing three-body abrasive wear and reducing wear volume by 50%. Furthermore, these textures facilitate the formation of hydrodynamic lubrication films and inhibit corrosion crack initiation in SBF, thereby enhancing mechanical stability and mitigating adhesive-oxidative wear. This research presents a superior manufacturing solution for developing high-performance medical devices.