氯化物熔体中镝铁合金形成的电化学研究  

Electrochemical Study on the Formation of DyFe Alloy in the Molten Chloride

作　　者：刘冠昆[1] 童叶翔[1] 洪惠婵[1] 杨绮琴[1] 陈胜洋 辜进喜 

机构地区：[1]中山大学化学系

出　　处：《中国稀土学报》1997年第4期300-303,共4页Journal of the Chinese Society of Rare Earths

基　　金：广东省科学基金

摘　　要：用循环伏安法、恒电位电解断电后的电极电位时间曲线、电位阶跃法和Ｘ射线衍射法研究了铁电极在ＮａＣｌＫＣｌＤｙＣｌ３熔体中的电化学行为，获知Ｄｙ３＋在Ｆｅ电极上的还原过程，首先是生成ＤｙＦｅ合金，然后才析出纯金属Ｄｙ；验证了ＤｙＦｅ合金体系中化学计量化合物的数目。计算了化学计量化合物在１０７３Ｋ的标准生成自由能，在１０２３～１１２３ＫＤｙ原子在ＤｙＦｅ合金相中的扩散系数与温度的关系式为ｌｎＤ＝－７２９×１０３／ＲＴ－１４７，其扩散活化能为７２９Ｋ·ｍｏｌ－１。用自耗阴极法制取了含Ｄｙ高达９０％的ＤｙＦｅ合金，其物相为ＤｙＦｅ３和Ｄｙ。?The cyclic voltammetry and electrode potentialtime curve after potentiostatic electrolysis, potentialstep method and Xray diffraction were used to study the electrode process of Dy3+ reduced on Fe cathode in molten NaClKClDyCl3. At first, the DyFe alloys forms, then the intermetallic compounds of DyFe containing more Dy form in sequence. The metallic Dy deposits at last. The number of compounds in DyFe alloy has been tested at 1073 K. The standard free energy of formation for (1/2)Dy2Fe17, (1/6)Dy6Fe23, DyFe3 and DyFe2 determined are -9264, -8310, -7699 and -5905 kJ/mol at 1073 K. The relationship between diffusion coefficient and temperature of Dy atom in DyFe layer can be expressed as lnD=-729×103/RT-147, and the diffusion activation energy is 729 kJ·mol-1. The DyFe alloy was prepared by consumable cathode in molten chlorides. The DyFe alloy contained Dy near 90%(wt) was obtained. The phases of alloy were DyFe3 and Dy.

关 键 词：镝铁合金 熔盐电解 电化学合金化 

分 类 号：TF64[冶金工程—钢铁冶金]