The project was supported by the National Natural Science Foundation of China(21271054，11575047，21173060);Major Research Plan of the National Natural Science Foundation of China(91326113，91226201);and Fundamental Research Funds for the Central Universities, China(HEUCF2016012)
Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, P. R. China
Abstract:
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.
