Synthesis Of Zn-Mg Alloy By DMF-MgCl 2 6H ₂ O-Ion Liquid Electrodeposition

Zn-Mg alloy is widely used in steel material and other material surface to improve the corrosion resistance and it becomes a ideal substitute for the upgrade of galvanized steel.Electrodeposition method becomes a best method for producing Zn-Mg alloy because of the composition and structure of alloy could be controlled by adjusting the parameter as well as its simple operation and equipment.The aqueous solution plating is a relatively common method to electroplate alloy plating,but difficult to have bigger breakthrough for serious hydrogen evolution because of very negative reduction potential of Mg （-2.37V vs.SHE）.Low temperature molten ionic liquids analogue have a wide electrochemical window、large liquid temperature range、no hydrogen evolution reaction and other significant advantages which is theoretically able to fully meet the Mg depositionexcellent, and become alternative solvents for electrodeposition of Zn-Mg alloyDimethylformamide （DMF） and MgCl2·6H₂O as materials synthesized ionic liquids analogue. Its physical and chemical properties characterized by viscosity, conductivity and cyclic voltammetry curves. The Zn-Mg alloy coating was deposited by adding a certain amount of ZnCl2 to DMF-MgCl2 H₂Oionic liquids analogue. The effect of the electrochemical behavior, composition and deposition conditions on the composition, morphology and corrosion resistance of the coating were analyzed and studied.DMF and MgCl2·6H₂O synthetics ionic liquids analogue through solvation processes,it shows good conductivity and increases with the rising of temperature but the viscosity instead. In the preparation of Zn-Mg alloys, the reduction of Zn2+ can induce Mg2+ to Mg and Zn-Mg alloy occurs underpotential co-deposition; the nucleation of Zn and Zn-Mg tends to three-dimensional instantaneous nucleation under electrochemical control at glassy carbon electrode and copper electrode,respectively; It can be got compact flat alloy plating under certain conditions, the thickness of chemical copper plating is about 2.2 μm and the alloy plating thickness is about 12 microns.Alloy coating shows good compactness and uniform particle,the particle size is about 2 μm and present a layered form; Zn and Mg uniformly distributed, the situation does not appear uneven distribution enrichment; the standard values of X-ray photoelectron spectroscopy of Mg （49.8 eV） is timed to coincide with the binding energy peak of Mg （49.8 eV） which is dealed with magnetic sputtering, it proves the existence of Mg metal atoms inalloy plating and provides an experimental basis to research and analysis Zn-Mg alloy deposition; Mg atoms insert in the lattic part of Zn atoms, forming a substitution solid solution and maintaining a hexagonal structure; the magnesium content increases as the cathode potential progressively more negative and the grains become fine with the increasing of the crystal nucleus forming speed; the magnesium content and particle size of Zn-Mg alloy increases as the temperature build-up, therefore, the alloy coating still showed good compactness; Zn-Mg alloy coating shows good corrosion resistant performance compared to the pure zinc plating, and it presents best corrosion resistant performance at Mg 1.25 at.% deposited at 353 K with constant potential of-1.2 V.