Electrodeposition of Zr and electrochemical formation of Mg–Zr alloys from the eutectic LiCl–KCl

Abstract

To investigate the electrodeposition mechanism of Zr(IV), the electrochemistry of a LiCl–KCl–K 2ZrF 6 melt at molybdenum and tungsten electrodes was studied at the temperature between 773 K and 973 K. Transient eletrochemical techniques, such as cyclic volatmmetry and chronopotentiometry were used. The results showed that Zr(IV) was reduced to Zr metal by a two-step mechanism corresponding to the Zr(IV)/Zr(II) and Zr(II)/Zr transitions. The intermediate product was identified as ZrCl 2 by X-ray diffraction. At a liquid magnesium electrode, Mg–Zr alloy was obtained by potentiostatic electrolysis, and the samples were characterized by scanning electron microscopy and energy dispersive X-ray detector. The zirconium concentration in samples was about 0.8 mass% determined by an inductively coupled plasma atomic emission spectrometer.