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+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.

Key words: Mg−Li−La alloys; La₂O₃; electrolysis; microstructure