Nanostructured titanium: Structure, mechanical and electrochemical properties

The electrochemical behavior of coarse-grained and nanostructured titanium in various media is studied by the methods of potentiodynamic polarization and impedance spectroscopy and by the analysis of the etching curves. It is found that the dissolution rate of nanostructured titanium increases in a Ringer- Locke solution at 37°C in comparison with the coarse-grained state owing to a more defective structure of the natural oxide layer on the surface of nanostructured titanium and its lower polarization resistance. It is demonstrated that the etching of nanostructured titanium in a mixture of hydrofluoric and sulfuric acids occurs mostly via the mechanism of local destruction, whereas overall uniform etching occurs in the case of coarsegrained titanium, which is considerably displayed in a range from 40 to 75°C.