Electrochemical behaviour and characterisation of plasma nitrided Ti–5Al–2Nb–1Ta orthopaedic alloy in Hanks solution

The present investigation deals with the study of the corrosion behaviour of glow discharge nitrided orthopaedic Ti–5Al–2Nb–1Ta alloy, using electrochemical techniques in Hanks solution. Potentiodynamic cyclic polarisation measurements show that the pit repassivation potential was higher in the case of nitrided alloy than the untreated alloy. The maximum pit repassivation potential was obtained for the alloy nitrided at 900 °C for 8 h. The electrochemical impedance spectroscopic (EIS) measurements showed an increased charge transfer resistance (Rct) and decreased double layer capacitance (Cdl) for nitrided alloys.