Electrochemical and SEM studies of a new implant bioalloy in physiological electrolytes

A new implant Ti-7Al-3V-2Mo-2Fe alloy was elaborated and its behaviour in Ringer-Brown and Ringer solutions (of different pH values) was studied using cyclic potentiodynamic and linear polarisation, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) with its link energy dispersive X-ray system (EDX). Cyclic potentiodynamic polarisation curves revealed that the Ti-7Al-3V-2Mo-2Fe alloy is self-passivated in Ringer solutions. Pitting corrosion appeared in alkaline Ringer solution but at very electropositive values of the breakdown and pitting protection potentials and it is not possible to develop local corrosion on this alloy, even in extreme functional conditions. EIS spectra at open circuit potential exhibited two phase angles characterising a resistant passive film and some charge transfer reactions. SEM-EDX analysis shows the presence of some aggregates containing complex compounds of calcium, magnesium, phosphor, silicon deposited on the alloy surface.