CORROSION RESISTANCE OF HIGH PRESSURE TORSION OBTAINED COMMERCIALLY PURE TITANIUM IN ACIDIC SOLUTION

The enhancement of commercially pure titanium (cpTi) mechanical properties, which is required for its medical application, can be achieved by grain refinement obtained by severe plastic deformation. In addition to mechanical properties improvement, excellent corrosion resistance of ultrafine-grained (UFG) cpTi in contact with human body fluids is required. Therefore, the aim of this study was to estimate electrochemical behavior of UFG cpTi obtained by high pressure torsion (HPT) under a pressure of 7,8 GPa at room temperature and up to 5 rotations. Electrochemical measurements were performed in artificial saliva at 37 degrees C in order to simulate oral environment, since development of UFG cpTi is primarily aimed for dental implant applications. Electrochemical behavior of UFG cpTi was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The obtained results indicate that HPT process, through significant grain size reduction, increases corrosion resistance of cpTi.