Publication

Abstract : The electrochemical behaviour of β titanium alloys, namely Ti–15Mo (TiMo) and Ti–29Nb–13Ta–4.6Zr (TNTZ), were studied under physiological conditions using open circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) measurements. The {OCP} data for {TNTZ} alloy indicated a noble behaviour compared to TiMo alloy. The current density value for {TNTZ} alloy calculated from polarization measurement was found to be comparable to that of TiMo. The {EIS} technique was applied to study the nature of the passive film formed on binary TiMo alloy at various impressed potentials and the results were compared with that of the quaternary {TNTZ} alloy. The {EIS} spectra obtained for TiMo alloy exhibited a single time constant for all potentials, indicating a highly compact passive layer over the surface. The {TNTZ} alloy, however, exhibited a single time constant at lower potentials and two time constants at higher potentials, indicating a bilayer structure at higher potentials.