Corrosion Behaviors of Mg-14Li-1Al-0.1Ce Alloy in NaCl Solutions

The corrosion characteristics of Mg-14Li-1Al-0.1Ce alloy in NaCl solutions were investigated by electrochemical measurements. The morphology of corroded surface was observed by scanning electron microscopy (SEM), the corrosion rates were investigated by weight-loss method and XRD was used to analyze the composition of corrosion layer and corrosion products deposited in solution. The results showed that the corrosion resistance of Mg-Li-Al-Ce alloy gradually deteriorated with increasing the concentration of Cl-. The corrosion rate of Mg-Li-Al-Ce alloy evaluated by Tafel extrapolation from polarization curves was much lower than that evaluated by weight-loss method. SEM observation showed that the alloy surface was broken more severely in higher Cl- concentration solutions. The corrosion layer formed on the surface of alloy could not inhibit corrosion, after removing the corrosion products attached on the alloy surface, deep pits and cracks were observed. Both corrosion layer and corrosion products deposited in solution consisted of Mg(OH)2, Li0.92Mg4.08 and Li3Mg7.