In this study, rods of magnesium alloy and titanium alloy were cut to have similar height of about 5mm and size of 10 mm × 10 mm to fabricate three Mg-Ti couples. The Mg-Ti couple was heat treated at 540 °C, 570 °C, and 600 °C. The corrosion of these couples have been investigated and compared with AZ31 alloy. Potentiodynamic polarization and electrochemical impedance spectroscopy measurements were employed to study the corrosion behavior after 1.0 h and 48 h exposure to 3.5% NaCl solutions. The morphology of surfaces was examined by scanning electron microscopy (SEM) and the profile analysis was collected using an energy dispersive X-ray (EDX) analyzer after 5 days immersion in the chloride solutions. It is found that coupling Mg with Ti reduces the corrosion of AZ31 alloy, which further decreased with the increase of the temperature of treatment. Prolonging the time of exposure from 1.0 h to 48 h remarkably decreased the corrosion of the couples as well.
Keywords: AZ31 alloy; Mg-Ti couple; corrosion; heat treatment; potentiodynamic polarization; surface morphology.