Evaluation of electrochemical properties of thermally oxidised Ti-6Al-4V for bioimplant application

The present study concerns development of a thin and adherent oxide film on the surface of Ti-6Al-4V by thermal oxidation and evaluation of its electrochemical properties for the possibility of its end use as coating on bio-implant. Thermal oxidation was carried out over a range of temperatures from 400 to 600°C and time ranging from 25 to 60 h. Surface oxidation leads to formation of an adherent oxide scale consisting of different oxides of titanium, mainly Ti2O3 and TiO2 (both rutile and anatase). A significant improvement in corrosion resistance (both corrosion potential and critical potential for pit formation) of the oxide layer was achieved by thermal oxidation. The oxidised surface showed a better wettability and pitting corrosion resistance against simulated body fluid