This study aims to investigate the anticorrosive properties of Zr2.5Nb alloy intended for possible applications in the human body; it was tested for 2 days in Ringer solution (an artificial analogue for human blood, considered the most corrosive body fluid). For Zr2.5Nb samples, in situ electrochemical measurements to assess the anticorrosive properties were applied, such as open circuit potential (OCP), polarization resistance (Rp), potentiodynamic polarization (PD) and cyclic voltammetry (CV). The electrochemical results show that the Zr2.5Nb alloy shows a positive and stable trend according to the open circuit potential, but with a modest corrosion rate in the form of pitting, deduced from the analysis of the polarization resistance and cyclic voltammetry data.

Nanoporous TiO₂ film is deposited on grade 5 Ti6Al4V implant alloy by electrochemical oxidation. The nanopores of the film, as highlighted by electron microscopy, have a mean diameter of 58.6 nm, which is measured and calculated from an average value of 10 measurements. The increase in oxygen concentration compared to the untreated alloy, which indicates the oxidation of the titanium alloy surface, is visualized using X-ray spectroscopy coupled to an electron microscope. The beneficial effect of the oxidation and controlled formation of the TiO₂ film on the implant alloy is proven by the comparative evaluation of degradation over time through the corrosion of both the untreated alloy and the alloy with an electrochemically formed and controlled TiO₂ film in Hank’s solution, which simulates the most corrosive biological fluid, blood. The results show that the electrochemical modification of the grade 5 titanium alloy to form a nanoporous TiO₂ surface film using the electrochemical oxidation method confirms the potential of improving the anticorrosive properties of titanium alloys used in implant applications.

The present work investigates the electrochemical behavior of the Zr2.5Nb alloy in a biomedical context, emphasizing the influence of electrochemical oxidation treatment on its stability in simulated physiological environments. The alloy samples were oxidized in 1 M H₂SO₄ under controlled voltages (200–275 V) and times (1 min), identifying 200 V–1 min as the optimal condition for obtaining a uniform porous oxide layer with an average pore diameter of ~90 nm. The corrosion resistance was evaluated using open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) in Ringer’s solution and Ringer’s solution containing 40 g/L H₂O₂ to simulate physiological and inflammatory conditions. Electrochemical tests revealed that electrochemically oxidized samples exhibited a polarization resistance up to 14.78 MΩ·cm², about 26 times higher than that of the untreated alloy (0.56 MΩ·cm²). After 77 h of immersion, the oxidized alloy maintained a high resistance (17.54 MΩ·cm²), confirming long-term stability. Scanning Electron Microscopy (SEM–EDX) and X-Ray Diffraction (XRD) analyses highlighted significant increases in oxygen content and the transformation from the monoclinic baddeleyite to the cubic arkelite phase of ZrO₂, contributing to enhanced corrosion resistance. These findings demonstrate that controlled electrochemical oxidation significantly improves the durability of Zr2.5Nb alloy in oxidative environments, supporting its potential for long-term biomedical implant applications.

In this study, the influence of the electrochemical oxidation process on Ti-Grad 23 alloy (Ti6Al4V ELI) in 1 M H₃PO₄, under applied voltages between 200 and 275 V, at a constant time of 1 min, is analyzed. The structural, morphological, and wettability properties of the TiO₂ anodic layers obtained were investigated by X-ray diffraction (XRD), energy dispersive electron microscopy (SEM-EDS), contact angle measurements, and chemical corrosion. XRD analysis showed the development and intensification of anatase and brookite phases, with increased crystallite size after electrochemical oxidation. SEM/EDS characterization confirmed the formation of an inhomogeneous porous TiO₂ layer, with pore diameters ranging from 98 to 139 nm and a significant increase in oxygen content. Contact angle measurements demonstrate enhanced hydrophilicity for all oxidized samples, with progressively lower values as the applied voltage increased. Chemical corrosion tests in Ringer solution and Ringer + 40 g/L H₂O₂ indicated that oxidized surfaces maintain structural stability in physiological media, whereas exposure to oxidizing environments induces partial pore closure and crack formation due to localized corrosion. The optimal anodizing condition was identified at 200 V for 1 min, yielding a uniform distribution of pores and improved morpho-functional characteristics suitable for biomedical applications. The optimal electrochemical oxidation conditions were identified at 200 V for 1 min, ensuring a uniform pore distribution.

This research investigates the effects of electrochemical oxidation on surface properties and corrosion performance of the Ti-6Al-4V ELI alloy intended for biomedical applications. Electrochemical anodization is performed in 1 M H₂SO₄ and 1 M H₃PO₄ electrolytes at applied potentials of 200, 250, and 275 V for 1 min. Morphological characteristics and chemical constitution of the oxide films are investigated by SEM-EDS analysis, while surface roughness, wettability, and microhardness are evaluated using profilometry, contact angle measurements, and Vickers microhardness testing. Electrochemical behavior is assessed by monitoring free potential (OCP) and electrochemical impedance spectroscopy in Ringer solution and Ringer solution containing 40 g/L hydrogen peroxide. Among the investigated conditions, anodization at 200 V for 1 min provides the most favorable surface morphology, producing well-defined and uniformly distributed nanopores while maintaining the structural stability of the oxide layer. Oxidation in 1 M H₂SO₄ leads to a more homogeneous nanoporous structure, higher surface roughness, improved hydrophilicity, and increased microhardness compared to 1 M H₃PO₄ treatment. Electrochemical impedance spectroscopy analysis reveals superior corrosion resistance for all oxidized samples in comparison with the untreated alloy. The oxide layers obtained in sulfuric acid exhibit the highest polarization resistance and electrochemical stability in simulated physiological environments.