Spectroscopic Characterization of Titanium Alloy Surface in a Biological Medium

E. Nouicera, F.Z. Benlahreche b and A. Nouicer c aCeramics laboratory, Physics Department, Constantine 1 University, Constantine 25000, Algeria bEngineering of Pharmaceutical Processes Faculty, Constantine 3 University, 25000, Algeria cElectrical Engineering Department, University of Skikda, BP26 Route Elhadaik, Skikda 21000, Algeria

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This work is aimed to study the effect of a biological medium simulated body fluid on surface modification of titanium alloy Ti6Al4V. Electrochemical techniques and the Raman spectroscopy are used. Polarization curves, plotted at different scan rates (5, 1, 0.5, and 0.2 mV/s), show a large range of passivation (above 3000 mV), with no occurrence of transpassivation. The return sweep shows the negative hysteresis with the shift of the corrosion potential in the more noble direction. The corrosion current is generally very low. These observations clearly confirm the high stability of the TiO2 passive film. The Raman spectroscopy shows that titanium dioxide formed consists of rutile phase. It was found that the scan rate has not a significant effect on the passivation phenomenon. However, it influences the corrosion potential and the current density. Electrochemical impedance spectroscopy allowed to establish the Nyquist diagrams and Bode around the equilibrium potential, and at different imposed potentials in the passivation field. The system behavior is not purely capacitive and so it is necessary to take in consideration the constant phase element. The impedance diagrams at different imposed potentials on the passivation field are composed only of a single loop.

DOI: 10.12693/APhysPolA.131.28 PACS numbers: 82.45.Bb, 82.80.Fk