Electrochemical characterisation of a PVD film of titanium on AISI 316L stainless steel

Linear sweep voltammetry and electrochemical impedance spectroscopy techniques were used to study the electrochemical behaviour of a thin film of titanium deposited on AISI 316L stainless steel by cathodic sputtering (PVD—physical vapour deposition). The aim was to evaluate one of the most important properties of an implant material, namely its corrosion rate. In order to simulate natural biological conditions, physiological serum (solution of NaCl 9 g L− 1) at pH = 6.3, thermostatically controlled at 37 °C) was used as the electrolyte. The voltammetry and electrochemical results obtained in this work show that the deposited film of titanium on AISI 316L is much more biocompatible than the AISI 316L stainless steel on it own, tested in the same experimental conditions. The titanium film has improved the passivity of the surface and the passive layer stayed stable with the immersion time.