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.