Effect of Impurity Fe Concentration on the Corrosion Behavior of Mg-14 mass%Li-1 mass%Al Alloy

Mg-Li system alloys with over 11 mass% Li have an excellent cold-workability in Mg alloys due to the bcc-structured crystal system. However this system alloys have poor corrosion resistance caused by Li solid-solution alloy. The corrosion resistance of conventional hcp-Mg alloys is influenced by the composition of impurity elements. Particularly, minute iron element deteriorates the corrosion resistance of Mg alloy and there is a threshold concentration on the corrosion rate in Mg alloys. In this study, the effect of iron element on the corrosion resistance of Mg-Li alloy was investigated by addition of iron. The corrosion resistance of Mg-Li with no Fe addition was higher than conventional Mg alloy. The corrosion rate of Mg-Li alloy increased with increasing iron concentration. However, there is no threshold iron concentration affected to the corrosion resistance on Mg-Li alloy.