Investigations of the Wettability and Electrochemical Corrosion Behavior of Nb2O5 Thin Films on a Ti45Nb Alloy

This study investigated niobium pentoxide (Nb2O5) thin films deposited by the sol-gel spin coating method on a Ti45Nb alloy, which are used in biomedical applications. To obtain a monoclinic Nb2O5 coating film and improve the properties of the films, the samples were annealed in an air atmosphere at 1300 °C for 2 hours. XRD, EDS, SEM, tensiometer, and potentiostat/galvanostat/ZRA studies were used to characterize the thin film coatings. In studies of the electrochemical performance in biological systems, the phosphate buffered saline (PBS) and the simulated body fluid (SBF) solutions were used to simulate bodily fluids for wettability and corrosion tests. In PBS solutions, the coated sample had a higher positive corrosion potential (E corr) of − 92 mV and a lower corrosion current density (I corr) of 2.86 × 10−6 mA/cm2 compared to the uncoated Ti45Nb. In the SBF solution, I corr values of 1.36 × 10−4 mA/cm2 and 7.37 × 10−5 mA/cm2 were obtained for the untreated and coated samples, respectively. The results obtained from the electrochemical corrosion tests of the hydrophilic Nb2O5-coated Ti45Nb samples indicated considerable improvement in the corrosion resistance relative to that of the untreated Ti45Nb alloy, as shown by a decrease in corrosion current density and an increase in the corrosion resistance. © 2023, ASM International.