Effect of indium addition on corrosion of AP65 magnesium alloy

Abstract

The effect of indium addition on the corrosion behavior of AP65 Mg alloy was examined. The indium modified AP65 exhibits accelerated pitting corrosion and overall corrosion, but there is almost no incubation period at the onset of corrosion. Polarization curve measurements indicate that the indium modified AP65 has more negative corrosion potential, which is an improvement aspect of the electrochemical activation. The corrosion current density increases from 0.126 to 0.868 mA/cm2 with and without 2.0% (mass fraction) indium addition. The mean potentials of AP65 negatively shift from −1.491 V to −1.584 V by adding 2.0% indium. The effect of indium addition on the corrosion performance of AP65 seems to be associated with the decrease of cathode-to-anode area ratio of the alloy, which may change the electrochemical anode and cathode polarization behavior of the alloy.