Electrochemical characterization of β-Ti alloy in Ringer's solution for implant application

Abstract

The corrosion behaviour of Ti–15Mo alloy in Ringer's solution was evaluated by potentiodynamic polarization, cyclic polarization and chronoamperometric/current–time transient (CTT) studies. The corrosion protective ability of Ti–15Mo alloy was compared with that of commercially pure (CP) titanium (grade-2) and Ti–6Al–4V alloy under similar experimental conditions. The microstructure, microhardness and structural characteristics were also evaluated to ascertain the suitability of these materials for orthopaedic implant applications. The study reveals that Ti–15Mo alloy possesses a β-phase microstructure and moderate hardness. The open circuit potential of Ti–15Mo alloy is relatively nobler than CP–Ti and Ti–6Al–4V alloy. The average passive current density of all the three Ti materials studied lies in the range of 32 × 10 −6 A/cm 2. The passivation range of Ti–15Mo alloy is relatively large when compared to that of Ti–6Al–4V alloy and CP–Ti. The loop area of the cyclic polarization curve of Ti–15Mo alloy is quite similar to that of Ti–6Al–4V alloy but relatively smaller than that of CP–Ti. There is no appreciable variation in the steady state current density of all the three Ti materials measured at +0.5 V vs. SCE whereas a significant variation is observed at +1.25 V vs. SCE. Based on the β-phase structure, moderate hardness and the ability to offer a better corrosion resistance in Ringer's solution, Ti–15Mo alloy can be used as a suitable alternative material for orthopaedic implant applications.