Zn-Al-Mg alloys with different alloying element contents between 1% to 2% were melted with a high frequency induction furnace. The microstructure of the alloys was analyzed by scanning electron microscopy(SEM) and X-ray diffraction. Effect of alloying element contents on electrochemical properties was studied. Results show that the Zn-Al-Mg alloys consist of Zn-rich block primary solidification structure and fine lamellar eutectic structure. Moreover, some Al-rich phase could be found in the Zn-2%Al-1%Mg alloy. Electrochemical test indicates that increasing Al and Mg content in the Zn-Al-Mg alloys decline corrosion current density. For alloys with 1%Al, more magnesium means lower corrosion potential. For alloys with 2%Al, however, more magnesium suggests higher corrosion potential. In Nyquist curves of electrochemical impedance spectroscopy (EIS) test, Warburg impedance portion could be found for all alloys. With increasing alloying elements content in the Zn-Al-Mg alloys, charge transfer resistance in higher frequency remarkably increase, which implies higher corrosion resistance.
