Electrochemical Analysis of Nano- and Micro-Sized Pore Formed Ti-6Al-4V Alloys in Solution Containing Ca, P, Mn, and Si Ions via Plasma Eletrolytic Oxidation for Bio-Implant Materials.

The purpose of this study was to investigate electrochemical analysis of nano- and micro-sized pore formed Ti-6Al-4V alloys in solution containing Ca, P, Mn and Si ions via plasma eletrolytic oxidation for bio-implant materials. The coatings were produced on Ti-6Al-4V alloy for dental implant using the plasma electrolytic oxidation (PEO) method in electrolytes with the various concentration of 0, 5, and 20% Mn and Si, respectively. Electrochemical potentiodynamic polarization and AC impedance behaviors were carried out in 0.9% NaCl solution at 36.5 ± 1 °C using potentiostat (Potentiostat, EG&G, 362) and electrochemical impedance spectroscope (EIS, EG&G, 1025). The potentiodynamic polarization test with a scan rate of 1.667 mV s was carried out from -1500 mV to 2000 mV. The frequency range used for EIS was 10²-10 Hz. The amplitude of AC signal was 10 mV and 5 points per decade was used. From the potentiodynamic polarization test, PEO treated alloy in electrolyte containing Ca, P, Mn, and Si show a lower corrosion potential than that on the bulk surface. In the case of Mn and Si doped surface, the corrosion resistance increase compared to non-doped surface with Mn and Si elements, and the current density was lower than that of the bulk surface. From the AC impedance test, in the case of Mn and Si doped surface, polarization resistance values were higher than other specimens, and nano- and micro-sized pores were covered with corrosion product consisted Mn and Si elements.