STUDY ON PREPARATION OF Al-Li-Gd ALLOYS BY ELECTROCHEMICAL CODEPOSITION FROM CHLORIDE MELTS
YAN Yongde1,2(), YANG Xiaonan2, ZHANG Milin2, WANG Li2, XUE Yun3, ZHANG Zhijian1
1 Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin 150001 2 Key Laboratory of Superlight Materials and Surface Technology (Ministry of Education) , Harbin Engineering University, Harbin 150001
Cite this article:
YAN Yongde, YANG Xiaonan, ZHANG Milin, WANG Li, XUE Yun, ZHANG Zhijian. STUDY ON PREPARATION OF Al-Li-Gd ALLOYS BY ELECTROCHEMICAL CODEPOSITION FROM CHLORIDE MELTS. Acta Metall Sin, 2014, 50(8): 989-994.
The electrochemical co-reduction process of Gd(III)and Al(III) and the preparation of Al-Li-Gd alloys were studied in LiCl-KCl-AlCl3-GdCl3 molten salt at 773 K by cyclic voltammetry, square wave voltammetry and chronopotentiometry. XRD, SEM-EDS were employed to characterize Al-Li-Gd alloys. The results suggested that the underpotential deposition (UPD) of Gd(III) on pre-deposited Al forms two Al-Gd intermetallic compounds. When current densities was higher than -279.5 mA/cm2, the co-reduction of Al, Li and Gd occurred. Different phases Al-Gd alloys can be obtained by adjusting the concentration of AlCl3. XRD indicated that the Al-Li-Gd alloys contain Al2Gd and Al2Gd3 phases. The analysis of SEM and EDS demonstrated that the element Gd distributes unevenly while Al is relatively uniform distribution.
Fund: Supported by High Technology Research and Development Program of China (No.2011AA03A409), National Natural Science Foundation of China (Nos.21103033, 21101040 and 91226201), Fundamental Research Funds for the Central Universities (No.HEUCF141502), Foundation for University Key Teacher of Heilongjiang Province and Harbin Engineering University (Nos.1253G016 and HEUCFQ1415) and Special Foundation of China and Heilongjiang Postdoctoral Science Foundation (Nos.2013T60344 and LBH-TZ0411)
Fig.1 Cyclic voltammograms of the LiCl-KCl melt system before and after the addition of AlCl3 at 773 K (scan rate: 100 mV /s, i— current density, E— potential)
Fig.2 Cyclic voltammogram of LiCl-KCl melt system containing both AlCl3 and GdCl3 at different cathodic limits at 773 K ( scan rate: 100 mV/s)
Fig.3 Square wave voltammogram of the LiCl-KCl-AlCl3-GdCl3 melt system at 773 K (pulse height: 25 mV; potential step: 1 mV; frequency: 20 Hz)
Fig.4 Chronopotentiograms of the LiCl-KCl-AlCl3-GdCl3 melt system at different current intensities at 773 K
Fig.5 Open-circuit chronopotentiogram electrodepositing at -2.45 V for 1 s in the LiCl-KCl-AlCl3-GdCl3 melt system at 773 K
Fig.6 XRD spectra of deposits obtained by galvanostatic electrolysis in the LiCl-KCl-AlCl3-GdCl3 (1%) melt system with different content AlCl3 at 923 K
Fig.7 SEM image (a) and elemental mappings of Al (b) and Gd (c) of Al-Li-Gd alloy obtained in LiCl-KCl-AlCl3 (15%)-GdCl3 (1%) melt system at 923 K
Fig.8 SEM image (a) and EDS analyses of points 1, 2 and 3 in Fig.8a (b~d) of Al-Li-Gd alloy obtained in LiCl-KCl-AlCl3(15%)-GdCl3 (1%) melt system at 923 K
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