Electrochemical Preparation of Quarternary Mg–Li–Al–Yb Alloy from Yb2O3 Assisted by AlCl3 in LiCl–KCl–MgCl2 Melt

Abstract

This work presents a study on direct preparation of quarternary Mg–Li–Al–Yb alloys in LiCl–KCl–MgCl2–AlCl3–Yb2O3 melt on W electrodes at 923 K. The electrochemical formation of intermetallics was investigated by electrochemical techniques of cyclic voltammetry and chronopotentiometry. The results showed that the deposition potential of Mg was a little more positive than that of Al–Yb alloy. The signals related to the formation of ternary Mg–Al–Yb intermetallics were detected in the melt. Quarternary Mg–Li–Al–Yb alloys were prepared via co-reduction of Mg(II), Li(I), Al(III) and Yb(III) on W electrodes at 923 K. Different intermetallics were identified via X-ray diffraction (XRD), and Al2Yb was found to be a stable phase in Mg–Li–Al–Yb alloys. The morphology and micro-zone chemical analysis of the bulk Mg–Li–Al–Yb alloys were characterized by optical microscopy (OM) and scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS). Moreover, the corrosion resistance property of Mg–Li–Al–Yb alloy was investigated in 3.5 wt% NaCl via potentiodynamic polarization.