Development of high-driving potential and high-efficiency Mg-based sacrificial anodes for cathodic protection

The electrochemical properties of Mg-Ca alloys for the development of high-efficiency and high-driving potential magnesium-based sacrificial anode were examined. The potentiodynamic tests were performed to evaluate the overall corrosion behavior of the anodes. Mg-Ca alloys exhibited greater anode performance than the conventional Mg-Mn and Mg-Al-Zn anodes. The improved performance of Mg-Ca anode in terms of driving potential and efficiency was attributed to: (1) the homogeneous and refined microstructures by small addition of Ca; and (2) the extremely electronegative potential of α-Mg.