XPS study of bioactive graded layer in Ti–In–Nb–Ta alloy prepared by alkali and heat treatments

Abstract

Ti and Ti-based alloys have been widely used for the biomedical applications due to their superiorities of biocompatibility, mechanical properties and corrosion resistance. However, there has been the limiting factor for these metals to show the low affinity to the living bone. Most of commercially used Ti alloys have harmful alloying elements such as Al, V, etc. The purposes of this study are design of new Ti alloy having the good mechanical properties and corrosion resistivity without harmful alloying elements and to improve the bone-bonding ability between Ti-based alloy and living bone through the chemically activated process (alkali treatment) and thermally activated one (heat treatment). Mechanical properties of the Ti–In–Nb–Ta alloy were observed by tensile test (Instron model 8511). Corrosion potential and corrosion rate were investigated using a Potentiostate machine (EG&G, Princeton Applied Model 273, Boston, USA) with saline solution (9% NaCl) without dissolved oxygen at 37°C. After alkali and heat treatments, the effects of the pre-treatments on the bonding property were evaluated by in vitro test. In this study, the surface changing behavior, which is apatite formation, of newly designed Ti–In–Nb–Ta alloy without harmful alloying elements was investigated through analyzing its surface by using X-ray photoelectron spectroscopy after surface activation treatments (alkali and heat treatments) and after subsequent soaking in the simulated body fluid.