biocompatibility ; electrochemical properties ; passive film ; Ti-Ag alloys
Abstract
Titanium and its alloys are widely used in biomedical, and dental fields: because of their excellent corrosion resistance, biocompatibility, high strength to weight ratio and good fatigue properties. It is well known that titanium is protected from corrosion due to the stability of passive film that controls and determines the corrosion resistance of titanium. The stability of passive film can also determine biocompatibility of titanium and its alloys. The purpose of this study was to evaluate the electrochemical properties of Ti-Ag alloys and the stability of passive film in artificial saliva. We designed Ti-Ag alloys with silver contents ranging from zero to 5.0 at% in steps of 0.5 at%. The alloys were arc-melted, homogenized, hot-rolled to 2 mm in thickness, and finally solution heat-treated for I hour and quenched in water. Potentiodynamic and potentiostatic testing were performed and open circuit potential of the Ti-Ag alloys was measured in artificial saliva 3, Passive film of the Ti-Ag alloys was analyzed by XPS(x-ray photoelectron spectroscopy).
- Ti Ag alloys showed low-passive current density and electrochemically stable behavior in the artificial saliva and passive film of the Ti-Ag alloys was composed of TiO2, Ti203 and TiO. As Ag content mc`.iz~ased, TiO2 fraction increased and titanium oxide layer of the Ti-Ag, alloys formed thicker than that of titanium.lt is thought that Ti-Ag alloys can be adopted and used safely with good biocompatibility for dental application