Remarkable bioactivity, bio-tribological, antibacterial, and anti-corrosion properties in a Ti-6Al-4V-xCu alloy by laser powder bed fusion for superior biomedical implant applications

Ti-6Al-4V alloys, widely used as medical implants, suffer from low wear resistance inhuman body fluids, restricting their applications in the biomedical field. This study fabricated a series of novel Ti-6Al-4V-xCu (x = 3, 5, 8, 10 wt%) alloys using laser powder bed fusion (L-PBF) to find a good combination of excellent bio-tribological, corrosion resistance, antibacterial property, and bioactivity. Results showed that the microstructure was comprised of ά and Cu-rich β phase in the Ti-6Al-4V-3Cu and −5Cu alloys, while the ά+Cu-rich β + nano Ti₂Cu microstructures were observed in the alloys with Cu content above 8 wt%. The micro-hardness, bio-tribological, and corrosion resistance of Ti-6Al-4 V-xCu alloys were significantly improved with increasing the Cu content, and the L-PBF Ti-6Al-4V-10Cu alloy exhibited the best combination of properties: the micro-hardness reaches 596.8 HV, ascribed to the solid solution, grain refinement, and precipitation strengthening; the corrosion density is ∼ 2 orders and a wear rate ∼ 1 order of magnitude lower than Ti64 alloy, showing optimal corrosion and bio-tribological properties; and the antibacterial rates against E. coli. and S. aureus reach ∼ 98% and ∼ 100%. The newly developed Ti-6Al-4V-xCu alloy was demonstrated with non-cytotoxicity and excellent antibacterial property, which is a promising candidate for superior biomedical implant applications.