Preparation of Mg–Li—La alloys by electrolysis in molten salt

Abstract

An electrochemical method was used to prepare Mg—Li—La alloys in a molten LiCl—KCl—KF—MgCl2 containing La2O3 at 943 K. The results showed preparation of Mg—Li—La alloys by electrolysis is feasible. The Mg—Li—La alloys were analyzed by means of X-ray diffraction (XRD), optical micrograph (OM) and scanning electron microscopy (SEM). XRD analysis indicates that α+Mg17La2, α+β+Mg17La2 and β+LaMg3 Mg—Li—La alloys with different lithium and lanthanum contents were obtained via galvanostatic electrolysis. The microstructures of typical α+β+Mg17La2 and β+LaMg3 phases of Mg—Li—La alloys were characterized by optical microscopy (OM) and scanning electron microscopy (SEM). The analysis of energy dispersive spectrometry (EDS) shows that the element of Mg distributes homogeneously in the Mg—Li—La alloy and the element of La mostly exists at grain boundaries to restrain the grain growth rate due to the larger ionic radius and lower electronegativity compared with Mg.