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Effects of gallium and lead on the electrochemical behavior of Al-Mg-Sn-Ga-Pb as anode of high rate discharge battery

2016; Elsevier BV; Volume: 695; Linguagem: Inglês

10.1016/j.jallcom.2016.11.176

1873-4669

Hamed Moghanni‐Bavil‐Olyaei, Jalal Arjomandi, Mostafa Hosseini,

Magnesium Alloys: Properties and Applications

The electrochemical performance of Al, Al–0.5 Mg–0.1 Sn–0.03 Ga–0.007 Pb (Alloy 1) and Al–0.5 Mg–0.1 Sn–0.05 Ga–0.07 Pb (Alloy 2) (wt.%) in 2 M NaCl solution has been investigated by using open circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy and galvanostatic discharge. The results suggest that the protective oxide layer on the Alloy 2 is unstable and pitting corrosion in weak points is evident while the Al surface is covered with passive layer. The addition of lead and gallium alloying elements to aluminum causes significant activation of aluminum. Gallium and tin as alloying additives in alloy composition can result in the adsorption of Cl− ions in the active sites at more electronegative potentials and therefore activate the alloy. The activation is revealed by shifting the open circuit potential in the negative direction, considerable increasing of corrosion current density and removal of the passive potential region. The extent of activation depends on the amount of the alloying elements and there is an increase in the following order: Al < Alloy 1 < Alloy 2. The galvanostatic discharge tests, combined with the results of impedance and potentiodynamic polarization confirmed the great activity of Alloy 2 compared to Alloy 1 and Al.