Electrochemical and Spectroscopic Study on the Corrosion of Ti–5Al and Ti–5Al–5Cu in Chloride Solutions

In this study, manufacturing of Ti–5Al and Ti–5Al–5Cu alloys were accomplished employing mechanical alloying technique. The corrosion resistance in 3.5 wt% NaCl solution of Ti–5Al and Ti–5Al–5Cu alloys was investigated using cyclic polarization (CPP), electrochemical impedance spectroscopy (EIS) and chronoamperometric current–time measurements. The corroded surfaces of Ti–5Al and Ti–5Al–5Cu were examined by the use of a scanning electron microscopy and energy dispersive X-ray spectroscopy. It is found that Ti–5Al suffers both uniform and pitting corrosion, particularly with prolonging the time of exposure period in the chloride solution. While, the addition of Cu, Ti–5Al–5Cu alloy, increases the intensity of uniform corrosion and decreases the probability of pitting attack. Prolonging the immersion time to 48 h before measurement decreases the corrosion of Ti–5Al alloy, while increases the corrosion of Ti–5Al–5Cu.