Al-Ag alloy formation by aluminium underpotential deposition from AlCl3+NaCl melts on silver substrate

Abstract

Aluminium was incorporated into silver electrodes by underpotential deposition from an equimolar AlCl3 + NaCl melt at 200• C and 300• C. The process was studied by linear sweep voltammetry and potentiostatic deposition/galvanostatic stripping. The deposits were characterized by electron probe and glancing incidence X-ray diffraction. The electrochemical measurements showed clear evidence of formation of two intermetallic compounds. This was confirmed by the analysis, which showed two layers of successive bulk intermetallic compounds. The Gibbs energy of formation of the compounds is calculated and the kinetics of growth is described.K e y w o r d s : aluminium-silver alloys, underpotential deposition, diffusion, microscopy and microanalysis techniques, Gibbs energy of formation, kinetics

Aluminium/zirconium alloys obtained by Al underpotential deposition onto Zr from low temperature AlCl3+NaCl molten salts

“…The procedures used for the preparation of the electrolyte -chloroaluminate molten salt and pre-electrolysis of the melt were identical to those described in a previous work. 15 Linear sweep voltammetry (LSV) experiments were performed in the potential range starting from an initial potential, E i (slightly negative to the zirconium reversible potential) to a final negative potential, E f (15-100 mV negative to the aluminum reversible potential) followed by a return scan. Voltammograms recorded in the aluminum underpotential deposition range included a similar potential range scanned, except that the scan direction was changed when the potential reached E f of 0.010 to 0.050 V positive to the aluminum reversible potential, and sometimes this E f potential was held for τ d of 1, 5 and 10 min.…”

Magnesium underpotential deposition from nitrate melts and alloy formation with platinum substrate

“…Metal electrodeposited under underpotential deposition (UPD) conditions (electrodeposition of metals on foreign substrates at potentials more positive than the equilibrium potential of the depositing metal) from aqueous, non-aqueous solutions and melts (even at room temperatures) onto a cathode of a different metal can diffuse into the substrate and generate alloys [19][20][21][22][23][24][25]. Alloys obtained by overpotential electrochemical deposition (OPD) and UPD can have different chemical and phase structures from the alloys of the same composition obtained by metallurgical (thermal) methods [8,[20][21][22][23][24][25].…”

“…Alloys obtained by overpotential electrochemical deposition (OPD) and UPD can have different chemical and phase structures from the alloys of the same composition obtained by metallurgical (thermal) methods [8,[20][21][22][23][24][25]. Recently, magnesium/platinum alloys formation by electrochemical means has been the subject of interest because of their applications in chemical power sources, jewelry and prosthetic aids [3,4,5,6,[26][27][28][29][30].…”

Magnesium–Gold Alloy Formation by Underpotential Deposition of Magnesium onto Gold from Nitrate Melts

“…It is known that metals electrodeposited by underpotential deposition (electrodeposition of a metal onto foreign substrate at potentials more positive than the equilibrium potential of the depositing metal-UPD) onto a cathode of a different metal, generally, can diffuse into the substrate and generate alloys [23,[37][38][39][40][41]. Alloys obtained by electrochemical deposition (overpotential deposition-OPD and UPD) can have different chemical and phase structures than the alloys of the same chemical composition obtained by metallurgical (thermal) methods [23,25,26,[37][38][39][40][41].…”

“…Alloys obtained by electrochemical deposition (overpotential deposition-OPD and UPD) can have different chemical and phase structures than the alloys of the same chemical composition obtained by metallurgical (thermal) methods [23,25,26,[37][38][39][40][41].…”