Electrochemical preparation of aluminium-nickel alloys by under-potential deposition in molten fluorides

JOURNAL OF ALLOYS AND COMPOUNDS

卷:471

Article

Gibilaro, M.¹  Massot, L.¹  Chamelot, P.¹  Taxil, P.¹ 

[1] Univ Toulouse 3, Lab Genie Chim, Dept Procedes Electrochim, UMR 5503, F-31062 Toulouse 9, France

关键词: Molten fluorides;    Aluminium;    Reactive electrode;    Aluminides;    Under-potential deposition;   

DOI  :  10.1016/j.jallcom.2008.03.115

来源: Elsevier

【 摘 要 】

The electrochemical behaviour of AlF3 was investigated in LiF-CaF2 medium first with inert tungsten and then with reactive nickel electrodes. Cyclic voltammetry, square-wave voltammetry and chronopotentiometry indicated that the reduction of Al(III) in Al(0) is a single-step process exchanging three electrons: Al(III) + 3e(-) = Al The electrochemical reduction is controlled by the diffusion of AlF3 in the solution. On a nickel electrode, a depolarisation effect for Al(III) reduction was observed in cyclic voltammetry due to the formation of Al-Ni alloys when aluminium ions react with the nickel substrate. Galvanostatic and potentiostatic electrolyses on a nickel electrode led to the formation of four nickel aluminides characterised by SEM: AlNi3, AlNi, Al3Ni2 and Al3Ni. Layers with a uniform composition of AlNi3, AlNi and Al3Ni2 were prepared by varying the electrolysis potential, the current density and duration of intermetallic diffusion. (c) 2008 Elsevier B.V. All rights reserved.

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