Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 32759
The Effects of NaF Concentration on the Zinc Coating Electroplated in Supercritical CO2 Mixed Zinc Chloride Bath

Authors: Chun-Ying Lee, Mei-Wen Wu, Li-Yi Cheng, Chiang-Ho Cheng

Abstract:

This research studies the electroplating of zinc coating in the zinc chloride bath mixed with supercritical CO2. The sodium fluoride (NaF) was used as the bath additive to change the structure and property of the coating, and therefore the roughness and corrosion resistance of the zinc coating was investigated. The surface characterization was performed using optical microscope (OM), X-ray diffractometer (XRD), and α-step profilometer. Moreover, the potentiodynamic polarization measurement in 3% NaCl solution was employed in the corrosion resistance evaluation. Because of the emulsification of the electrolyte mixed in Sc-CO2, the electroplated zinc produced the coating with smoother surface, smaller grain, better throwing power and higher corrosion resistance. The main role played by the NaF was to reduce the coating’s roughness and grain size. In other words, the CO2 mixed with the electrolyte under the supercritical condition performed the similar function as brighter and leveler in zinc electroplating to enhance the throwing power and corrosion resistance of the coating.

Keywords: Supercritical CO2, zinc-electroplating, sodium fluoride.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1093794

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1995

References:


[1] M. G. Fontana, and N. D. Greene, Corrosion Engineering, 3rd ed., New York: McGraw-Hill, 1986.
[2] F. A. Lowenheim, Modern Electroplating, 3rd ed., New York: John-Wiley, 1963.
[3] H. Yoshida, M. Sone, A. Mizushima, K. Abe, X.T. Tao, S. Ichihara, S. Miyata, "Electroplating of nanostructured nickel in emulsion of supercritical carbon dioxide in electrolyte solution,” Chemistry Letters, vol. 11, pp. 1086-1087, 2002.
[4] T.F.M. Chang, M. Sone, A. Shibata, C. Ishiyama, Y. Higo, "Bright nickel film deposited by supercritical carbon dioxide emulsion using additive-free Watts bath,” Electrochimica Acta, vol. 55, pp. 6469-6475, 2010.
[5] T.F.M. Chang, M. Sone, "Function and mechanism of supercritical carbon dioxide emulsified electrolyte in nickel electroplating reaction,” Surface and Coatings Technology, vol. 205, pp. 3890-3899, 2011.
[6] N. Shinoda, T. Shimizu, T.F.M. Chang, A. Shibata, M. Sone, "Filling of nanoscale holes with high aspect ratio by Cu electroplating using suspension of supercritical carbon dioxide in electrolyte with Cu particles,” Microelectronic Engineering, vol. 97, pp. 126-129, 2012.
[7] M. S. Kim, J. Y. Kim, C. K. Kim, and N. K. Kim, "Study on the effect of temperature and pressure on nickel-electroplating characteristics in supercritical CO2," Chemosphere, vol. 58, pp. 459-465, 2005.
[8] S.T. Chung, H.C. Huang, S.J. Pan, W.T. Tsai, P.Y. Lee, C.H. Yang, M.B. Wu, "Material characterization and corrosion performance of nickel electroplated in supercritical CO2 fluid,” Corrosion Science, vol. 50, pp. 2614-2619, 2008.
[9] V.C. Nguyen, C.Y. Lee, F.J. Chen, C.S. Lin, T.Y. Liu, "Study on the internal stress of nickel coating electrodeposited in an electrolyte mixed with supercritical carbon dioxide,” Surface and Coatings Technology, vol. 206, pp. 3201-3207, 2012.
[10] C. V. Nguyen, C. Y. Lee, F. J. Chen, C. S. Lin, L. Chang, "An Electroplating Technique using the Post Supercritical Carbon Dioxide Mixed Electrolyte,” Surface & Coatings Technology, vol. 232, pp.234-239, 2013.