Electrolytic aluminium-plating in fused salts based on chlorides

Abstract

Electrolytic aluminium-plating of iron bases in fused salts based on chlorides was investigated. As base electrolytes, the ternary AlCl₃-NaCl- KCl mixtures containing 76–80 wt.% AlCl₃ and 20–24 wt.% of NaCl and KCl in the ratio of 1:1 were found to be the most effective. The quality of the deposited Al layer was further improved by an addition of 5 wt.% NaI. The best results were obtained in the temperature range 150–200°C with a cathodic current density of up to 7 A dm^-2. Under these conditions, aluminum was deposited in the form of a fine-crystalline, silver-bright and non-porous layer.