Microstructural and corrosion characteristics of tantalum coatings prepared by molten salt electrodeposition

SURFACE & COATINGS TECHNOLOGY

卷:235

Article

Lee, Y. J.¹  Lee, T. H.²  Kim, D. Y.¹  Nersisyan, H. H.²  Han, M. H.¹  Kang, K. S.³  Bae, K. K.³  Shin, Y. J.⁴  Lee, J. H.² 

[1] Chungnam Natl Univ, Grad Sch Green Energy Technol, Taejon 305764, South Korea

[2] Chungnam Natl Univ, Dept Met Engn, Grad Sch, Taejon 305764, South Korea

[3] Korea Inst Energy Res, Taejon 305343, South Korea

[4] Korea Atom Energy Res Inst, Taejon 305353, South Korea

关键词: Molten salt;    Electroplating;    Tantalum;    Corrosion resistance;    Coating layer;   

DOI  :  10.1016/j.surfcoat.2013.09.007

来源: Elsevier

【 摘 要 】

A study has been conducted on the electrodeposition of tantalum in a 61 mol% LiF-39 mol% NaF melt containing 1 mol% K2TaF2 at 800 degrees C. Tantalum was coated onto a stainless-steel base (SUS316L) by molten salt electrodeposition (MSE) at different current densities (0.5, 1.5, 2, 5, 10,20 mA/cm(2)). Electrodeposition of metallic tantalum occurred primarily by electroreduction of Ta(V), i.e. TaF72-, at a potential of <-027 V (vs. Pt used as a pseudo reference electrode). At potentials less than -0.324 V, TaF2(s) also underwent reduction to metallic tantalum. Pure metallic tantalum, without any entrapped salt, was successfully deposited on SUS316L by electrodeposition at 5 mA/cm(2). This showed that the deposition efficiency and microstructure of the tantalum coating layer were strongly dependent on the current density. The densest microstructure was obtained at a current density of 5 mA/cm(2). Current densities above 5 mA/cm(2) caused non-uniform microstructures because of rapid deposition. A dense microstructure and an intact coating layer contributed to a significant enhancement in corrosion resistance. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.

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