The electrochemical impedance spectroscopy study of ultrafine-grained titanium in artificial saliva

Abstract

The enhancement of mechanical properties of commercially pure titanium (cpTi) can be achieved by grain refinement obtained by severe plastic deformation, but corrosion resistance of ultrafinegrained (UFG) cpTi is still under discussion. Therefore, the aim of this study was to estimate electrochemical behavior of UFG cpTi obtained by high pressure torsion under a pressure of 7.8GPa with a rotational speed of 0.2 rpm up to 5 rotations at room temperature. Electrochemical measurements were performed in artificial saliva with pH value of 4.0 at 37°C in order to simulate oral environment, because UFG cpTi is primarily developing for dental implant applications. UFG cpTi was investigated by electrochemical impedance spectroscopy (EIS). The obtained results indicate that HPT process significantly reduces the grain size and UFG cpTi shows better corrosion resistance compared to its coarse-grained (CG) counterpart.