ELECTROCHEMICAL CHARACTERIZATION OF BIOMEDICAL TITANIUM ALLOY Ti-35Nb-7Zr-5Ta

The β titanium alloy Ti-35Nb-7Zr-5Ta (TNZT) has been recently developed as a new implant material. This alloy is composed of non-toxic elements with low modulus of elasticity and is ideal for implant applications. The aim of present study was to evaluate the corrosion resistance of this alloy in an artificial physiological solution. In the present work, the electrochemical behavior of TNZT alloy has been studied using simulated human body environment. Hank’s solution was used for simulating body fluid conditions. This evaluation was carried out through potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) tests, which were conducted at 25±2C. The electrochemical behaviour of commercially pure titanium (CPT) was also evaluated for comparison purpose. The results indicated stable passive polarization behaviour for TNZT alloy. Corrosion rates were determined by Tafel extrapolation method. The corrosion rate of TNZT alloy was comparable but lower than that of CPT. However, TNZT alloy exhibited less noble breakdown potential and passive range compared to CPT. The passive current density of TNZT alloy is also observed to be lower than that of CPT.