2. Collaborative Innovation Center of Nonferrous Metals

Abstract—the corrosion behaviors of AZ61 magnesium alloy with the Ca addition have been studied in this paper. These alloys were prepared in an induction melting furnace with an Al2O3 crucible under a mixed atmosphere of CO2 and SF6. The corrosion tests were completed using immersing in 0.5% and 3.5 % NaCl solution for 4 hours at room temperature with no stirring. The phase analysis was performed by XRD. Olympus optical was used to characterize the microstructure and phases of magnesium alloys. Scanning electron microscopy was used to exhibits the morphologies of corroded surfaces of magnesium alloys after removal of the corrosion products. The results exhibited that with the addition of alloy element Ca, the microstructure of AZ61 magnesium alloy was remarkably refined, and the spotted, high-melting point phase Al-Ca intermetallic compounds can be found. With the addition of different content Ca, the corrosion behavior of AZ61 alloy decreases firstly and then increases sharply. When the content of Ca is 1%, AZ61 magnesium alloy shows the lowest corrosion rate. And the corrosion rate of AZ61-1 % Ca alloy is 2.19 and 2.87 mm/a at 0.5 % and 3.5 % NaCl solution respectively. Keywords-magnesium alloy; AZ61; corrosion behavior; alloy element Ca; microstructure (key words) I