在NaCl-KCl-Tb4O7-AlF3体系中为了制备Al-Tb合金,首先对熔盐中的上清液和沉淀物进行了分析,X射线衍射(XRD)结果确定了Tb4O7能被AlF3氟化生成TbF3。采用一系列的电化学方法对NaCl-KCl-AlF3-Tb4O7体系在Mo电极上的电化学行为进行了研究。循环伏安、方波伏安、计时电位和开路计时电位等电化学方法的研究结果表明T b(III)在预先沉积的Al电极上发生欠电位沉积。在不同条件下进行恒电流电解制备了Al-Tb合金,并对所得合金样品进行XRD和扫描电镜-能量散射谱(SEM-EDS)表征。结果表明在-2.5A进行恒电流电解得到的Al-Tb合金是由Al和Al3Tb两相组成。采用电感耦合等离子体-原子发射光谱仪(ICP-AES)对实验所得沉积物的组成进行分析,研究了电解条件对合金组成和电流效率的影响。在电流强度为-1.5A进行恒电流电解2h,电流效率可达76.5%。
To prepare Al-Tb alloys from Tb4O7 assisted by AlF3 in NaCl-KCl melts, we initially studied the effect of AlF3 on the dissolution of Tb4O7 by analyzing the supernatant and bottom salts. X-ray diffraction (XRD) results revealed that Tb4O7 was fluorinated by AlF3 to form TbF3. The electrochemical behavior of the NaCl-KCl-AlF3-Tb4O7 system was investigated using a Mo electrode at 1073 K. Cyclic voltammetry (CV), square wave voltammetry (SWV), chronopotentiometry (CP) and open circuit chronopotentiometry (OCP) analyses indicated that the under-potential deposition of Tb(III) occurred on pre-deposited Al. The co-deposition of Al-Tb alloys was investigated by galvanostatic electrolysis under different conditions. These samples were characterized by XRD and scanning electron microscopy and energy dispersive spectrometry (SEM-EDS). The Al-Tb alloy obtained by galvanostatic electrolysis at -2.5 A consisted of Al and Al3Tb phases. The effects of the electrolysis conditions on the composition of the alloy and current efficiency were studied by analyzing the compositions of the Al-Tb alloys by inductively coupled plasma-atomic emission spectrometer (ICP-AES). The current efficiency could reach 76.5% under the conditions of galvanostatic electrolysis at -1.5 A for 2 h.