Structure and Corrosion Resistance of Zn-Ni and Zn-Ni-W Coatings

Article Preview

Abstract:

Zn-Ni and Zn-Ni-W coatings were prepared by the electrodeposition under the galvanostatic conditions (jdep. = -0.020 A cm-2) from the zinc bath containing additionally ions of nickel (Zn-Ni) and ions of nickel and tungsten (Zn-Ni-W). The Zn-Ni coating after electrodeposition was subjected to outside passivation and in the Zn-Ni-W coating the passive function performs tungsten (inside passivation). The surface morphology of the coatings was studied using a scanning electron microscope (JEOL JSM - 6480). Chemical composition of obtained coatings was determined by the X-ray fluorescence spectroscopy (XRF). Phase composition investigations were conducted by X-ray diffraction method using a Philips diffractometer. Electrochemical corrosion resistance investigations were carried out in the 3% NaCl, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. On the basis of these investigations it was found that Zn-Ni coating is more corrosion resistant than the Zn-Ni-W coating.

You might also be interested in these eBooks

Info:

Periodical:

Materials Science Forum (Volumes 636-637)

Pages:

1042-1046

Citation:

Online since:

January 2010

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2010 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] K.R. Baldwin, C.J.E. Smith: Trans. Inst. Met. Finish. Vol. 74 (1996), p.202.

Google Scholar

[2] W. Peng, Y. Wang: J. Cent. South Univ. Technol. Vol. 14(1) (2007), p.37.

Google Scholar

[3] B. Veeraraghavan, B. Haran, S.P. Kumaraguru, B. Popov: J. Electrochem. Soc. Vol. 150(4) (2003), p. B131.

Google Scholar

[4] B. Veeraraghavan, H. Kim, B. Popov: Electrochim. Acta Vol. 49 (2004), p.3143.

Google Scholar

[5] N.R. Short, S. Zhou, J.K. Bennis: Surf. Coat. Technol. Vol. 79 (1996), p.218.

Google Scholar

[6] Y.P. Lin, J.R. Selman: J. Electrochem. Soc. Vol. 140 (1993), p.1299.

Google Scholar

[7] R. Karimi - Shervedani, A. Lasia: J. Electrochem. Soc. Vol. 144(8) (1997), p.2652.

Google Scholar

[8] R. Karimi - Shervedani, A. Lasia: J. Electrochem. Soc. Vol. 145(7) (1998), p.2219.

Google Scholar

[9] R. Karimi - Shervedani, A. Lasia: J. Appl. Electrochem. Vol. 29 (1999), p.979.

Google Scholar