Effect of tin addition on microstructure and electrochemical properties of rolled AZ61-Sn magnesium anodic materials

Microstructure characterization, corrosion behavior, and electrochemical properties of magnesium anode materials containing 1-3 wt.% Sn in AZ61 alloy were studied by optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS), constant current method, potential polarization, and drainage. The results showed that amount of Mg2Sn phase increased, and recrystallization ratio of Sn-contained Mg alloys during rolling process was improved with increasing of Sn content. This resulted in uniform and refined grains. The results also demonstrated that discharge potential was improved and hydrogen release rate was reduced with the addition of Sn. As the current density increased, the release hydrogen rate was rising, owing to negative variance effect of magnesium alloys. The current efficiency gets to 87% at 20 mA/cm(2). The main components of the corrosion products are easy-to-peel-off MgO and Al2O3 that can lead to more negative and stable work potential and accelerate battery reaction continuously.