Studies on the influence of chloride ion concentration and pH on the corrosion and electrochemical behaviour of AZ63 magnesium alloy

Magnesium-based light alloys belong to a class of structural materials with increasing industrial attention. Magnesium alloys show the lowest density among the engineering metallic materials, low cost and large availability. As a consequence, this light alloys have a promising future. The paper presented reveals the influence of chloride ion concentration and pH on the corrosion and electrochemical behavior of AZ63 magnesium alloy in NaCl solution. The experimental techniques used include immersion studies and potentiodynamic polarization tests. The corrosion rate was very high in highly acidic solutions (pH 2) as compared to that in other solutions. The corrosion rate usually increased with the decrease in pH and the increase in chloride ion concentration. But the quantity of the increase in corrosion rate was different at separate pH and concentration regions. The corrosion potential usually shifted to more negative values with the increase in concentration of chloride ions and the decrease in pH of solution. (C) 2004 Elsevier Ltd. All rights reserved.