Fundamental studies on electrochemical processing light weight alloys

Abstract

The electrochemical synthesis of aluminum-lithium alloys by a novel in-situ processing was investigated. The electrolyte used was LiF-CaF2 with lithium compounds, Li20 and Li2C03. Lithium obtained by dissociation of its compounds deposited into the liquid aluminum cathode at the bottom. The fundamental parameters studied were: (l) solubility of lithium compounds; (2) anodic overvoltages of LiF-CaF2 electrolyte; (3) Liquidus temperatures of the electrolytes. The solubility was found to increase from 11.42 wt % at 1078 K to 14.77 wt % at 1133 K for Li20. For Li2C03 it increased from 2.95 wt % at 1063 K to 7.57 wt % at 1093 K. Anodic overvoltages were measured as a function of current density and reaction mechanisms were analyzed. A limiting current density phenomenon was observed at 0.011 A/cm2 for the LiF-CaF2-Li2C03 and at 0.52 A/cnr for LiF-CaF2-Li20 systems. The liquidus temperatures of the electrolyte saturated with the lithium compounds were determined.