Effect of thermo-mechanical processing on the corrosion resistance of Ti6Al4V alloys in biofluids

Ti6Al4V-ELI alloy was plastically deformed at elevated temperatures in the range of β and α + β fields and was subsequently heat treated; so that five different alloys were obtained. The corrosion resistance of these alloys was studied in Ringer solutions of different pH values using the techniques of electrochemical cyclic potentiodynamic polarization, electrochemical impedance spectroscopy and scanning electron microscopy. All alloys exhibited high corrosion resistance in Ringer solutions for 2000 exposure hours. SEM observations indicated the formation of calcium phosphate on the alloy surface. Two electric equivalent circuits with two time or three time constants were fitted.