Investigation of monolayer anodized TiO2 film and bilayer spin coated graphene film on corrosion and tribocorrosion properties of Ti45Nb alloy

This study investigates the structural, corrosion, and tribocorrosion properties of Ti45Nb alloy coated with monolayer and bilayer films. Ti45Nb samples were ultrasonically degreased, anodized in a H2SO4 and H3PO4 solution, and coated with graphene oxide (GO) films via spin coating and subsequent annealing. The anodized samples exhibited anatase and rutile phases, while GO films displayed characteristic Raman shifts indicating graphite oxidation. Corrosion tests in simulated body fluid (SBF) revealed enhanced corrosion resistance in bilayer samples, evidenced by a lower corrosion current density (2.28×10-6 A/cm2) and a higher corrosion potential (10 mV) compared to monolayer and untreated samples. Electrochemical impedance spectroscopy (EIS) indicated superior charge transfer resistance (9.72 Ωcm2) for bilayer coatings. Tribocorrosion tests demonstrated reduced wear rates and coefficient of friction (COF) in bilayer films, attributed to increased surface hardness and load-carrying capacity. The findings suggest that the bilayer coating significantly enhances the corrosion and tribocorrosion resistance of Ti45Nb, making it a promising material for biomedical applications.