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Journal of Applied Electrochemistry

, Volume 17, Issue 2, pp 261–269 | Cite as

Formation of corrosion-resistant layers by electrodeposition of refractory metals or by alloy electrowinning in molten fluorides

  • Pierre Taxil
  • Jean Mahenc
Papers

Abstract

The electrolytic treatment of less resistant metals such as iron, copper and nickel with tantalum or niobium has been carried out in K2TaF7-LiF-NaF or K2NbF7-LiF-NaF solutions in the 550 to 1050°C temperature range. Two kinds of experiments have been used.
  1. (i)

    At lower temperatures, electroplating with pure tantalum and niobium on inert cathodes was performed. The electrodeposition mechanism of each metal was studied and coherent electroplates were prepared which were tested in electrocatalytic applications.

     
  2. (ii)

    At higher temperatures (850–1050°C), using nickel cathodes, intermetallic compounds were obtained at more positive potentials than that for pure electrodeposition (Ta2Ni, TaNi, TaNi2, TaNi3, NbNi, NbNi3). The electrowinning of stable TaNi3 and NbNi3 layers was carried out by the metalliding process which makes these materials resistant to corrosion in various media. Further, a study of the kinetics of growth of the diffusion layer allowed a diffusion parameter to be determined which was in agreement with other results obtained by conventional methods.

     

Keywords

Nickel Fluoride Niobium Intermetallic Compound Tantalum 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman and Hall Ltd. 1987

Authors and Affiliations

  • Pierre Taxil
    • 1
  • Jean Mahenc
    • 1
  1. 1.Laboratoire de Chimie Physique et d'Electrochimie, Laboratoire Associé au CNRS UA 192Université Paul SabatierToulouse CedexFrance

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