NANOTUBULAR OXIDE FORMATION ON BIOMEDICAL TITANIUM ALLOYS

Titanium and its alloys, particularly commercially pure titanium (cpTi, Grade 2) and Ti-6Al-4V Extra Low Interstitial (ELI), are widely used in biomedical implants due to their excellent biocompatibility and mechanical properties. Surface modifications such as nanotubular oxide formation can further enhance their biological performance by improving osseointegration, corrosion resistance, and antibacterial properties. In this study, cpTi and Ti-6Al-4V ELI were anodized to form nanotubular titanium oxide layers. The anodization process was carried out in an ethylene glycol-based electrolyte containing ammonium fluoride, with an applied potential of 80 V for 30 minutes. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to characterize the morphology and chemical composition of the resulting oxide layers. SEM analysis revealed well-organized nanotubular structures on both alloys, with an average inner diameter of approximately 90 nm and nanotube lengths of about 1.1 microns. However, the Ti-6Al-4V ELI alloy exhibited voids in the nanotubular layer, corresponding to regions of the beta phase. EDS analysis confirmed the presence of titanium dioxide (TiO₂) as the primary component of the oxide layer, with the Ti-6Al-4V ELI alloy also showing traces of aluminum, vanadium, and fluorine incorporated during the anodization process. These results demonstrate that both cpTi and Ti-6Al-4V ELI can form nanotubular oxide layers with distinct morphological and compositional features. The differences in nanotube density and the presence of alloying elements in Ti-6Al-4V ELI suggest potential influences on the mechanical and biological properties of the anodized surfaces, making them suitable for tailored biomedical applications.