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Mg-Li alloy metal material is by far the most representative of the ultra-light alloy, aviation, aerospace and electronics industries ideal structural material. Now to get a good quality magnesium-doped lithium alloy multi-use method, this method also has some drawbacks, it is difficult to meet the rapid development of science and technology on the lightweight material requirements. Therefore it is necessary to find technical, economical preparation process, and promote Mg-Li alloy in more fields has been widely used. In this paper, LiCl-KCl-MgCl2 system using molten salt as the electrolyte of electrodeposited Mg-Li-Pr alloys. First, physical and chemical properties of molten salt in the electrolyte LiCl-KCl, LiCl-KCl-KF, LiCl-KCl-MgCl2 adding an excess of Pr6O11, Pr6O11 studied the solubility in the molten salt and volatile. The results show that: Pr6011 in LiCl-KCl molten salt is insoluble; in LiCl-KCl-KF molten salt solubility is small; while in KCl-LiCl-MgCl2 molten salt solubility is relatively large, and promote Pr6O11 dissolved substances MgCl2, Pr6O11 dissolution almost entirely accomplished by chemical dissolution, XRD analysis results that the following reactions may be molten: 2MgCl2 (l) Pr6O11 (s) = PrCl3 (1) 4PrO2 (s) PrOCl (s) 2MgO (s) , its solubility with temperature and MgCl2, the increase of the content, the temperature is 750 ℃, MgCl2 content accounted for 15.9% of the total mass of molten when the solubility of up to 1.76% Pr6O11. Therefore, this paper chose electrolyte system KCl-LiCl-MgCl2, adding Pr6O11 prepared by co-electrodeposition Mg-Li-Pr alloys; volatilization tests showed: KCl-LiCl-MgCl2 molten salt system of volatility as the temperature and concentration of MgCl2 The increases. Using electrochemical workstation using cyclic voltammetry Li, Mg2 with Pr3 on the electrochemical behavior of molybdenum wire. The results showed that: praseodymium and lithium deposited on the previously deposited on an inert cathode magnesium, potential positive shift occurred upd form, which is conducive to Mg-Li praseodymium ternary alloy codeposition. By studying the current density, temperature, electrolyte composition on the alloy content of each component and the current efficiency was obtained Mg2, Li, Pr3 ternary deposition process parameters: temperature electrolysis 650 ℃, current density greater than 8.5 A/cm2, Li (mol) / Mg2 (mol) ratio of greater than 8.4. With the current efficiency and reduce temperature electrolysis, when electrolysis temperature is 650 ℃, when the current density of 8.5 A/cm2 maximum current efficiency of 78.3%. Scanning electron microscopy (SEM), X-ray diffraction (XRD), optical microscopy analysis (OM), hardness and other analytical and testing methods, systematic study of the rare earth praseodymium on Mg-Li-Pr alloy microstructure and hardness. The results showed that: prepared by molten salt electrolysis of Mg-Li-Pr alloys, praseodymium Mg3Pr intermediate compounds in the presence of the phase reticular and evenly distributed in the grain boundary, Mg3Pr intermediate compounds of the alloy grain refinement has obvious and can effectively improve the hardness of the alloy.
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