Optimized Mechanical Properties,Corrosion Resistance and Bactericidal Ability of Ti-15Zr-xCu Biomedical Alloys During Aging Treatment

The effects of different aging conditions on the microstructure, strength, corrosion resistance, cytotoxicity and antibacterial ability of Ti-15Zr-xCu (3 ≤ x ≤ 7, wt%) (TZC) alloys were systematically investigated. Microstructural evolution and behavior were analyzed by X-ray diffraction (XRD) patterns and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), while potentiodynamic polarization technique was employed to characterize the corrosion response of the alloys after solution-treatment and aging (STA). High-temperature aging at 660 °C for 4 h (660-4) gave the best combination of properties by enabling significant precipitation of the Cu-rich Ti₂Cu and Zr₂Cu compounds, and mild formation of the Zr₇Cu₁₀ secondary phase. The high kinetics at this condition was beneficial to the complete precipitation and more homogeneous distribution of the intermetallic particles. These led to the inhibition of dislocation movements and allowed for significantly improved mechanical strengths with added ductility, availability of more Cu ions for the desired oligodynamic activity without evoking cytotoxicity, better corrosion resistance and very high antibacterial ability (over 99.5%), thus improving the overall properties of the TZC alloys for biomedical applications.