Biofunctional surfaces by plasma electrolytic oxidation on titanium biomedical alloys

Abstract

The effects of substrate composition on oxide layer properties following plasma electrolytic oxidation under similar conditions have been evaluated for α-cpTi, α/β-Ti6Al7Nb, β-Ti35Zr10Nb and β-Ti45Nb alloys. All oxidised surfaces revealed enhanced wettability, surface free energy and roughness relative to the non-oxidised surfaces. Nevertheless, the resultant oxides differed with respect to average pore size, pores density, layer chemistry and phase composition. The β-titanium alloys developed oxides with a larger average pore size and lower pore density relative to the α-cpTi and α/β-Ti6Al7Nb substrates. Anatase dominated the oxide layer formed on α-cpTi and β-Ti45Nb alloys, a mixture of anatase and rutile was present on the oxidised α/β-Ti6Al7Nb surface, whereas Ti₂ZrO₆ was the only phase detected on the oxidised surface of the β-Ti35Zr10Nb alloy.