{"title":"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","volume":91,"journal":"International Journal of Materials and Metallurgical Engineering","pagesStart":665,"pagesEnd":671,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/9998806","abstract":"
This research studies the electroplating of zinc coating
\r\nin the zinc chloride bath mixed with supercritical CO2. The sodium
\r\nfluoride (NaF) was used as the bath additive to change the structure
\r\nand property of the coating, and therefore the roughness and corrosion
\r\nresistance of the zinc coating was investigated. The surface
\r\ncharacterization was performed using optical microscope (OM), X-ray
\r\ndiffractometer (XRD), and α-step profilometer. Moreover, the
\r\npotentiodynamic polarization measurement in 3% NaCl solution was
\r\nemployed in the corrosion resistance evaluation. Because of the
\r\nemulsification of the electrolyte mixed in Sc-CO2, the electroplated
\r\nzinc produced the coating with smoother surface, smaller grain, better
\r\nthrowing power and higher corrosion resistance. The main role played
\r\nby the NaF was to reduce the coating’s roughness and grain size. In
\r\nother words, the CO2 mixed with the electrolyte under the supercritical
\r\ncondition performed the similar function as brighter and leveler in zinc
\r\nelectroplating to enhance the throwing power and corrosion resistance
\r\nof the coating.<\/p>\r\n","references":"[1] M. G. Fontana, and N. D. Greene, Corrosion Engineering, 3rd ed., New\r\nYork: McGraw-Hill, 1986.\r\n[2] F. A. Lowenheim, Modern Electroplating, 3rd ed., New York: John-Wiley,\r\n1963.\r\n[3] H. Yoshida, M. Sone, A. Mizushima, K. Abe, X.T. Tao, S. Ichihara, S.\r\nMiyata, \"Electroplating of nanostructured nickel in emulsion of\r\nsupercritical carbon dioxide in electrolyte solution,\u201d Chemistry Letters,\r\nvol. 11, pp. 1086-1087, 2002.\r\n[4] T.F.M. Chang, M. Sone, A. Shibata, C. Ishiyama, Y. Higo, \"Bright nickel\r\nfilm deposited by supercritical carbon dioxide emulsion using\r\nadditive-free Watts bath,\u201d Electrochimica Acta, vol. 55, pp. 6469-6475,\r\n2010.\r\n[5] T.F.M. Chang, M. Sone, \"Function and mechanism of supercritical\r\ncarbon dioxide emulsified electrolyte in nickel electroplating reaction,\u201d\r\nSurface and Coatings Technology, vol. 205, pp. 3890-3899, 2011.\r\n[6] N. Shinoda, T. Shimizu, T.F.M. Chang, A. Shibata, M. Sone, \"Filling of\r\nnanoscale holes with high aspect ratio by Cu electroplating using\r\nsuspension of supercritical carbon dioxide in electrolyte with Cu\r\nparticles,\u201d Microelectronic Engineering, vol. 97, pp. 126-129, 2012.\r\n[7] M. S. Kim, J. Y. Kim, C. K. Kim, and N. K. Kim, \"Study on the effect of\r\ntemperature and pressure on nickel-electroplating characteristics in\r\nsupercritical CO2,\" Chemosphere, vol. 58, pp. 459-465, 2005.\r\n[8] S.T. Chung, H.C. Huang, S.J. Pan, W.T. Tsai, P.Y. Lee, C.H. Yang, M.B.\r\nWu, \"Material characterization and corrosion performance of nickel\r\nelectroplated in supercritical CO2 fluid,\u201d Corrosion Science, vol. 50, pp.\r\n2614-2619, 2008.\r\n[9] V.C. Nguyen, C.Y. Lee, F.J. Chen, C.S. Lin, T.Y. Liu, \"Study on the\r\ninternal stress of nickel coating electrodeposited in an electrolyte mixed\r\nwith supercritical carbon dioxide,\u201d Surface and Coatings Technology, vol.\r\n206, pp. 3201-3207, 2012.\r\n[10] C. V. Nguyen, C. Y. Lee, F. J. Chen, C. S. Lin, L. Chang, \"An\r\nElectroplating Technique using the Post Supercritical Carbon Dioxide\r\nMixed Electrolyte,\u201d Surface & Coatings Technology, vol. 232,\r\npp.234-239, 2013.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 91, 2014"}