Cathodic reduction process of Al-Cu-Y alloy in fluoride-oxide eutectic system via molten salt electrolysis

作     者：Xu Wang Chunfa Liao Yunfen Jiao Hao Tang 

作者机构：School of Metallurgy and Chemical EngineeringJiangxi University of Science and Technology 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2018年第36卷第3期

页      面：324-330页

核心收录：

学科分类：080603[工学-有色金属冶金] 08[工学] 0806[工学-冶金工程] 

基　　金：Project supported by the National Natural Science Foundation of China(51564015) 

主　　题：Fluoride oxide eutectic Al Cu Y alloy Molten salt electrolysis Cyclic voltammetry Electrode process Rare earths 

摘      要：Al-Cu-Y alloys were prepared by molten salt electrolysis in fluoride-oxide system composed of electrolyte（Na3 AlF6-AlF3-LiF-MgF2） and oxide（Al2 O3-CuO-Y2 O3）. Cathodic reduction process of Al2 O3,CuO and Y2 O3 were analyzed by cyclic voltammetry and chronoamperometry. Components and phase composition of alloy samples prepared by potentiostatic electrolysis were characterized by scanning electron microscopy and energy dispersive spectroscopy. The results show that the Al-Cu-Y alloy can be prepared in the AIF3-NaF-5 wt%LiF-5 wt%MgF2（NaF/AlF3 = 2.2, molecular ratio） eutectic system with mixed oxide（Al2 O3-CuO-Y2 O3） through 2 h at the conditions of a temperature of 1208 K, cell voltage3.0 V, cathode current density 0.7 A/cm^2. Al（Ⅲ） and Cu（Ⅱ） ions can be reduced to zero valence Al（0） and Cu（0） directly on carbonaceous electrode surface by instantaneous nucleation, respectively, the reduction process is controlled by diffusion. The reduction potential of Y（Ⅲ） ions is close to the active ions of fluoride melts, but strengthened phase AI3 Y can be formed through electrochemical reduction and alloyed process with active Al（Ⅲ） and Cu（Ⅱ） ions, meanwhile, the Al2 Cu and Al3 Y phases are distributed at the grain boundary of Al matrix.