Preparatory Electrodeposition Process for High Purity Bulk Aluminum

Abstract

Electrodeposition for Al from a dimethylsulfone (DMSO2) bath was consecutively performed, applying two types of current waveforms such as direct current and pulsed current, to investigate the effect of a current type on the preparatory electrodeposition (pre-electrodeposition) process. Electrodeposited Al from a DMSO2 bath has a nanograined structure and high strength. However, the electrodeposits showed no plastic deformability due to the large amount of sulfur and chlorine which were incorporated into the electrodeposits as sulfide and chloride. Therefore, we obtained high purity Al from a DMSO2 bath using pre-electrodeposition process, which could decrease sulfur and chlorine contents without using additives. The sulfur and chlorine contents of electrodeposits, obtained from a DMSO2 bath applying both types current, both decreased to approximately 0.1 at.%. This result indicated that the waveforms made no difference in pre-electrodeposition process.