Electrochemical impedance spectroscopic characterisation of passive film formed over β Ti–29Nb–13Ta–4.6Zr alloy

The β Ti–29Nb–13Ta–4.6Zr (TNTZ) has been recently developed as a new implant material. TNTZ alloy is composed of non toxic elements and has a low modulus of elasticity than the other titanium alloys. However, its electrochemical behaviour has not yet been studied. Hence in the present work, the influence of potential on electrochemical behaviour of TNTZ alloy under simulated physiological condition was investigated by electrochemical impedance spectroscopy (EIS). The experimental results were compared with those obtained for titanium (Cp–Ti). All measurements were obtained in aerated Hank’s solution at 37 °C and at different potentials Ecorr, 0 mV (SCE), 500 mV (SCE) and 1000 mV (SCE). The EIS behaviour of the TNTZ alloy is unique in nature compared to Cp–Ti, exhibiting two-time constants indicating the formation two layers only at higher potentials.