Achieving Extreme Wettability Transition on 3D-Printed Titanium Alloys for Tribological Properties Improvement via Femtosecond Laser and Anodic Oxidation

Titanium alloy Ti-6Al-4 V (TC4) is widely employed in orthopedic implants due to its superior mechanical properties and enhanced corrosion resistance. However, the biocompatibility and wear resistance of TC4 surfaces are imperfect, thereby restricting the application in medical use. Therefore, regulation of topological structures and extreme wettability transition on TC4 surfaces is required. Single-step surface modification techniques often fail to simultaneously improve both the hydrophilicity and wear resistance of TC4 surfaces. To overcome this limitation, this work introduces a novel strategy integrating femtosecond laser ablation with anodization to enhance the biocompatibility and tribological properties of 3D-printed TC4 components. Initially, femtosecond laser was used to fabricate groove structures on 3D-printed TC4 surfaces, followed by anodization of the femtosecond laser-ablated TC4 surface. This approach aims to endow TC4 surfaces with optimized wettability and wear resistance, extending the life span of TC4 components. The chemical composition and morphology of modified TC4 surfaces were characterized to elucidate the formation mechanism of the micronano structures resulted from synergistic effects of laser ablation and anodization. Through controlling topological structure and chemical composition of TC4 surfaces, a practical application of manufacturing of 3D-printed TC4 components is expected to be possible due to their enhanced hydrophilicity and wear resistance for 3D-printed TC4 implants.