Simultaneous improvement of corrosion resistance and bioactivity of a titanium alloy via wet and dry plasma treatments

Abstract

The fabrication of bioactive oxide layers on Ti–6Al–4V alloy by combining of wet and dry plasma methods for optimizing the chemical stability and biological activity together was reported. To achieve this goal, dry plasma sputtering depositions of Mg and Zn in the RF and DC modes, respectively, were performed for 5 and 20 min on the surface of titanium oxide obtained by wet plasma electrolytic oxidation of Ti–6Al–4V alloy substrate. Zn and Mg particles were successfully introduced into the titanium oxide layer which not only leads to decrease the fraction and size of microdefects but also increases the fraction of biocompatible anatase phase in compassion to that in the un-sputtered oxide layer. The corrosion resistance of sputtered oxide layers was superior to the un-sputtered layer. Regarding the hydroxyapatite formation and cell proliferation, Zn and Mg particles incorporated in less amounts in the sample sputtered for 5 min were of considerable significance in facilitating the nucleation and growth of hydroxyapatite and proliferation of MC3T3-E1 on the surface of this sample. Thus, the oxide layer containing Zn and Mg particles would be used as a promising implant material due to its great intrinsic chemical stability and osteointegration ability.