Investigation On Physicochemical Properties Of DyF₃-LiF Main System Melts

Dysprosium copper alloys have the advantages of improving the Hall effect and magnetic resistance of materials,improving the magnetic properties of alloys,and have wide application prospects in the preparation of magnetostrictive materials,magnetic refrigeration materials,neodymium-iron-boron additives and the like.Therefore,it is of great practical significance to study the methods of energy-saving,environmental protection,stability,and large-scale production of beryllium copper master alloys.In this paper,the single oxides?Dy₂O₃,Cu₂O?with different mass fractions and different temperatures?1183K¹303K?were added in the LiF-DyF₃ molten salt system using the rotation method,Archimedes method,pull tube method,and continuously changing conductivity cell constant method.This article uses these methods to determine the impact in viscosity,density,surface tension and conductivity of the molten salt system and determines the reasonable temperature and oxide addition range of the molten salt system Selecting the appropriate temperature and oxide addition amount for exploratory electrolysis to prepare the beryllium copper alloy Cyclic voltammetry,chronoamperometry,and chronopotentiometry were used to analyze the electrochemistry of Dy?III?and Cu?I?at the electrode surface of LiF-DyF₃ molten salt system by adding electrolytic materials?Dy₂O₃,Cu₂O?.Mechanism,determine the reduction potential of Dy?III?,Cu?I?,the number of electron migration,ion diffusion coefficient,nucleation method,ion reduction step,etc.,for the mechanism study of the alloying process.The results show that with the temperature of LiF-DyF₃,LiF-DyF₃-Dy₂O₃ and LiF-DyF₃-Cu₂O systems increases,the viscosity is decreasing,the density is decreasing,the conductivity is increasing,but the surface tension of LiF-DyF₃ and LiF-DyF₃-Cu₂O systems is decreasing.The surface tension of the LiF-DyF₃-Dy₂O₃ system is increasing.The increase of Dy₂O₃ content in the LiF-DyF₃-Dy₂O₃ system will cause the system viscosity to decrease,the density to increase,the surface tension to decrease,the electrical conductivity to increase,The increase of Cu₂O content in LiF-DyF₃-Cu₂O system will cause the system viscosity to decrease,the density to increase,the surface tension to decrease,the electrical conductivity to increase.However,when the addition amount of Cu₂O is more than 1.0wt%,the viscosity and density of the system tend to be stable without increasing the amount of addition.However,the surface tension tends to be 0.22?/(N·m^-1)when the amount of Dy₂O₃ added is about 2.0wt%;the effects of alloy phase diagrams,energy conservation,and the addition of different oxides on the physicochemical properties of the system The Cu₅Dy-based copper dysprosium master alloy was prepared by the exploratory electrolytic electrolysis using LiF-DyF₃-Dy₂O₃?2wt%?-Cu2O?1wt%?as the electrolysis system at a temperature of 1243K;Cu?I??Cu?0?in the LiF-DyF₃ system.The reduction potential is between-0.6V and-0.5V,and the reduction potential of Dy?III??Dy?0?is between-0.7V and-0.6V.The precipitation potential of Dy-Cu alloy is between-1.4V and-1.3V and the three reduction processes are all one-step reduction.The reduction process is controlled by diffusion.Cu?I?diffusion rate is 3.47×10^-3cm²/s.The diffusion rate of Dy?III?is 1.34×10^-2cm²/s.The Cu?I?nucleation is a continuous nucleation.The nucleation of Dy?III?and the alloying process are the continuous nucleation and the instantaneous nucleation.