Tailoring the microstructure and enhancing the corrosion resistance of extruded dilute Mg-0.6Al-0.5Mn-0.25Ca alloy by adding trace Ce

The effect of trace Ce addition on the microstructure evolution and corrosion behavior of dilute Mg-0.6Al-0.5Mn-0.25Ca-xCe (x = 0.1–0.3 wt%) alloys were investigated using immersion tests and electrochemical measurements. The Ce addition caused the formation of Al8Mn4Ce and Al11Ce3, which were less noble than Al8Mn5. Strikingly, the alloy containing 0.3 wt% Ce exhibited the lowest average corrosion rate of 4.13 mm y−1, which was 6.5 times lower than that of Ce-free alloy. The outstanding anti-corrosion properties were attributed to the low potential difference between Ce-containing phases and matrix, the compact composite oxide film (MgO-CeO2-Al2O3), and the enrichment of Fe in Ce-containing phases.