Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (9): 2301-2308.doi: 10.3866/PKU.WHXB201606032

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Preparation of Mg-Zr Alloys in KCl-MgCl2-K2ZrF6-ZrO2 Molten System

Tao JIANG1,Jie TIAN1,Ning WANG1,Shu-Ming PENG1,*(),Mei LI2,Wei HAN2,Mi-Lin ZHANG2   

  1. 1 Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621999, Sichuan Province, P. R. China
    2 Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, P. R. China
  • Received:2016-03-21 Published:2016-09-08
  • Contact: Shu-Ming PENG E-mail:pengshuming@caep.cn
  • Supported by:
    the Major Research Plan of the National Natural Science Foundation of China(91426302);National Natural Science Foundation of China(21301163)

Abstract:

To investigate the electrochemical co-reduction mechanism associated with the formation of Mg-Zr alloys, the electrochemical behaviors of Zr(IV) in KCl-MgCl2-K2ZrF6 and KCl-MgCl2-K2ZrF6-ZrO2 melts were studied on a molybdenum electrode at 1023 K. Cyclic voltammograms (CVs) and square-wave voltammograms (SWVs) showed that Zr(IV) was reduced to Zr metal by a two-step mechanism consisting of the Zr(IV)/Zr(II) and Zr(II)/Zr(0) pairs in the KCl-MgCl2-K2ZrF6 melt. The dissolution of ZrO2 in the KCl-MgCl2-K2ZrF6 melt was ascertained from CVs, while the Zr(IV) concentration in the melt was assessed by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mg-Zr alloys were obtained by galvanostatic electrolysis in KCl-MgCl2-K2ZrF6-KF-ZrO2 melts and subsequently characterized by X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The Zr concentrations in the alloys as determined by ICP-AES were as high as 7.2% (w). The formation of Mg-Zr alloys could be controlled by varying both the reaction time and the melt composition. These results confirm the feasibility of the direct electrolysis of ZrO2 to obtain Mg-Zr alloys in KCl-MgCl2-K2ZrF6-ZrO2 melts.

Key words: LiCl-KCl-K2ZrF6, ZrO2, Mg-Zr alloy, Preparation

MSC2000: 

  • O641