Effect of vanadium replacement by zirconium on the electrochemical behavior of ti6al4v alloy in ringer s solution
1 Gheorghe Asachi Technical University of Iasi, Faculty of Chemical Engineering and Environmental Protection, Department of Chemical Engineering
2 Department of Environmental Engineering and Management, 71 Mangeron Blvd., 700050, Iasi, Romania
2 Department of Environmental Engineering and Management, 71 Mangeron Blvd., 700050, Iasi, Romania
Abstract
The electrochemical behaviour of Ti6Al4V and Ti6Al4Zr alloys has been evaluated in Ringer's solution at 250C. The effect of the substitution of vanadium in Ti6Al4V alloy has been specifically addressed. The evaluation of the corrosion resistance was carried out through the analysis of the open circuit potential variation with time, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) tests. Very low current densities were obtained (order of nA/cm2) from the polarization curves and EIS, indicating a typical passive behaviour for both investigated alloys. The EIS results exhibited capacitive behaviour (large corrosion resistance) with phase angle close to -800 and high impedance values (order of 105 O cm2) at low and medium frequencies, which are indicative of the formation of a highly stable film on these alloys in Ringer s solution. In conclusion, the electrochemical behaviour of Ti6Al4V is not affected on substituting vanadium with zirconium.
Keywords
current corrosion; impedance; polarization; Titanium alloys