Electrochemical deposition of aluminum on W electrode from AlCl 3-NaCl melts

• Published in: Transactions of Nonferrous Metals Society of China 2010, Vol.20 (1), p.158-164
• Main Authors: KAN, Hong-min, WANG, Zhao-wen, WANG, Xiao-yang, ZHANG, Ning
• Format: Article
• Language: English
• Subjects: aluminum; electrodeposition; intermetallic compounds
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(09)60114-X

Electrochemical deposition of aluminum on W electrode from AlCl 3-NaCl melts was studied by cyclic voltammetry and chronopotentiometry. The results show that Al (III) is reduced in two consecutive steps, i.e., 4Al 2Cl 7 −+3e −→Al+7AlCl 4 − and then AlCl 4 −+3e −→Al+4Cl −. The electrochemical reaction of 4Al 2Cl 7 −+3e −→Al+7AlCl 4 − is reversible. Certain nucleation overpotential is required during the deposition of aluminum on W electrode. Chronopotentiometry analysis also shows that Al (III) is reduced in two consecutive steps under certain current density, which is in reasonable agreement with cyclic voltammograms. By using constant current deposition, the electrodeposits on Al substrate obtained at between 50 and 100 mA/cm 2 are quite dense and well adherent to the Al substrate. The electrochemical deposition of aluminum on Cu substrate in AlCl 3-NaCl melts indicates that the intermetallic compounds are formed. The intermetallic compounds are AlCu and Al 2Cu.