Corrosion behavior of an AZ31 magnesium alloy with deposited high purity magnesium film

The corrosion behavior of deposited magnesium film on AZ31 alloy, pure magnesium and AZ31 alloy were studied from the measurement of electrochemical impedance spectroscopy (EIS) in 0.5 mol/dm3 sodium chloride solution (pH 6.5) at 308K. The magnesium film on AZ31 alloy was prepared by evaporation process using 3N-Mg (99.9mass%Mg) material and the thickness of the film was 100 μm. The corrosion potentials of magnesium materials became negative value with decreasing these impurities contents. Corrosion resistance of magnesium materials measured by EIS increased with decreasing these impurities. It is found that the corrosion resistance and corrosion potential of deposited magnesium film correspond to that of 6N-Mg (99.9999mass%Mg).