Studies on the AlCl3/dimethylsulfone (DMSO2) electrolytes for the aluminum deposition processes

This paper presents a study of the aluminum deposition processes in dimethylsulfone (DMSO2)-based electrolytes. The electrical conductivities of the AlCl3/DMSO2 electrolytes were investigated as a function of temperature (70–180 °C) and molar ratio of AlCl3 to DMSO2 (from 0.1:1 to 0.8:1). The results show that the temperature-dependent conductivities of the electrolytes fit well with the Vogel–Tamman–Fulcher (VTF) equation. The optimum operating conditions for the electrodeposition of aluminum from AlCl3/DMSO2 electrolytes were determined based on the studies of the effects of current density, electrolyte temperature and the molar ratio of AlCl3 to DMSO2 on the quality of the deposited coatings. Dense, bright and adherent aluminum coatings were obtained in AlCl3/DMSO2 electrolytes over a wide range of temperatures (110–150 °C) and current densities (5 to 20 A dm− 2). The preliminary results from Al refining experiments showed that Al alloy can be purified via electrolysis in 0.2:1 AlCl3/DMSO2 at 130 °C with a current density of 10 A dm− 2.