Study On Preparation And Mechanism Of Cu-Ce,Sn-Ce,Sn-Mn Alloys By Electrolysis In Molten Salts

In recent years,the alloys are widely used in the field of aerospace due to many excellent properties,The study and preparation of the new alloy materials are very important to meet the needs of industry.The preparation of alloys by molten salt electrolysisattract the attention of many people,we have study the preparation and mechanism of alloys by electrolysis in this paper,detailed as follows:In the first section of this thesis,Cu�Ce alloys were prepared by cathodic alloying method on solid Cu electrode and codeposition method on an inert electrode in a molten LiCl�KCl eutectic.Cyclic voltammetry and square wave voltammetry indicate that the reduction of Ce ions into Cu metal occurs in a single step reaction and the number of electrons transfer is three.The underpotential deposition of cerium ions occurs at Cu electrode potential near-1.83 V vs Ag⁺/Ag.The process of reduction of cerium ions with Cu substrates was also investigated by open circuit chronopotentiometry.The diffusion coefficient of Ce?III?has been determined with the different scan rates of Cyclic voltammogram on solid Cu electrode.XRD,SEM and EDS result of deposits obtained by potentiostatic electrolysis on Cu electrodes indicate that Cu�Ce alloys are formed.In the second section of this thesis,we have research the electrochemical behavior of Sn and formation of Sn�Ce alloy by codeposition method from LiCl�KCl�SnCl₂�CeCl₃melt on a inert Electrode,Transient electrochemical techniques were used to study the reduction potential of Sn and Ce.The result indicate the potential value for the reduction of Ce³⁺ions were more positive than that of Ce metal deposition at a inert electrode.Sn�Ce alloys with different intermetallic compounds were prepared by galvanostatic electrolysis.The alloy sample was characterized by XRD.In the third section of this thesis,Electrochemical codeposition of Sn?II?and Mn?II?on a tungsten electrode in LiCl�KCl�SnCl₂�MnO₂ melts was investigated.The solid MnO₂could be chlorinated and formed MnCl₂ in LiCl�KCl�SnCl₂�MnO₂ melts.The results by cyclic voltammetry,Chronoamperograms and Open circuit chronopotentiometry showed that the potential of Sn and Mn metal deposition was�0.35 V vs.Ag/AgCl and�1.18 V vs.Ag/AgCl,respectively.Square wave voltammetry showed the reduction of Sn?II?and Mn?II?ions on an inert W electrode is an one-step reaction with two electrons exchanged.The diffusion coefficient of the Mn ions was calculated using the Berzins�Delahay equation,Sn�Mn alloys with different phases were prepared via potentiostatic electrolysis.The alloy sample was characterized by XRD.In this thesis,The electrochemical mechanism of alloys were investigated in the method of molten salts electrolysis.By controlling the electrochemical parameters to prepare the corresponding alloy,it provides a reliable theoretical basis and technical routine for the preparation of new alloy materials by molten salt electrolysis.