Publication Details
Abstract
Surface modification of titanium alloys is widely employed to improve their bioactivity and corrosion resistance for biomedical implant applications. In this study, Ti-13Nb-13Zr alloy samples were coated with SiO₂, BaTiO₃, and a SiO₂–BaTiO₃ composite using a spray pyrolysis technique. The coated specimens were immersed in simulated body fluid (SBF) for 30 days to evaluate their apatite-forming ability and bioactivity. The formation of hydroxyapatite and surface characteristics were investigated using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and field-emission scanning electron microscopy (FESEM). Electrochemical performance was assessed through open-circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). The results revealed successful hydroxyapatite formation on all coated surfaces, with the SiO₂–BaTiO₃ composite coating exhibiting the highest apatite-forming ability, as evidenced by increased hydroxyapatite peak intensity and a dense surface morphology. Electrochemical measurements demonstrated a significant improvement in corrosion resistance, with the composite-coated sample showing the lowest corrosion rate (1.883 × 10⁻⁵ mm·y⁻¹), a protection efficiency of 99.49%, and the highest impedance resistance after SBF immersion. The enhanced performance was attributed to the synergistic effect of SiO₂ and BaTiO₃, which promoted hydroxyapatite deposition and improved surface protection. These findings suggest that SiO₂–BaTiO₃ composite coatings deposited by spray pyrolysis are a promising surface modification approach for improving the bioactivity and corrosion resistance of Ti-13Nb-13Zr alloy used in biomedical implants.