| Magnesium alloys have been applied in many fields because of their excellent capabilities. Magnesium-lithium alloy is the lightest structural material among the magnesium alloys studied. It not only has the very predominance of magnesium alloys, but also has lower density, which made it would be widely used in various fields of communication and aeronautics. However, its poor corrosion and high chemical reactivity have hindered wide use of magnesium alloys in many applications. Studies on magnesium-lithium alloys were mainly focused on the synthesis technology of the magnesium-lithium alloy. The research on corrosion resistance method on magnesium-lithium alloy is seldom reported. Therefore, surface treatment is necessary to improve the corrosion resistance of magnesium alloys.In this paper, we studied a few methods of surface protection of magnesium-lithium alloy, including chemical converting films, electroless nickel plating and chemical conversion film plus electroless nickel plating. Technological process and operation conditions were investigated. The structure, composition, thickness and microhardness of the plating film were measured. It was found that the plating had excellent adhesive strength and corrosion resistance.The corrosion resistance capabilities of stannate chemical conversion film and phosphate coating were analyzed. The Ni-P layer was directly obtained on the surface of magnesium-lithium alloy by electroless technique. The structure of the Ni-P layer and its corrosion resistance were measured.Chemical conversion film plus electroless nickel plating on magnesium-lithium alloy was studied. The results indicated that the porous conversion film provides an advantage for the adsorption prior to electroless nickel plating. A Ni-P coating was successfully deposited on the conversion film. The potentiodynamic polarization indicated that the Ni-P coating deposited on the conversion film provides a good protection for the magnesium-lithium alloy.
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