Effect of Amino Acids on the Structure and Corrosion Resistance of Mg-Li Alloy Anodic Oxide Film

Abstract

In this paper, Mg-Li alloy anodic oxide films were prepared with different amino acid as additive. The microstructure and phase composition of the coatings were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The corrosion resistance was evaluated by potentiodynamic polarization techniques and electrochemical impedance spectroscopy (EIS). The results show that the main compositions of the anodic oxide films are MgO, Mg(OH)2 and LiOH. The anodic oxide films with amino acid as additive have uniformer surface and higher corrosion resistance than that without additive, but with the increase of the carbon chain of amino acid, the effect is reduced gradually.