Journal of Surface Science and Engineering (한국표면공학회지)

The Korean Institute of Surface Engineering (한국표면공학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Current Density on Porous Film Formation in Two-Step Anodizing for Al Alloy

  • Lee, Seung-Jun (Department of Power System Engineering, Kunsan National University) ;
  • Kim, Seong-Jong (Division of Marine Engineering, Mokpo National Maritime University)
  • Received : 2016.04.11
  • Accepted : 2016.04.29
  • Published : 2016.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Anodizing is a technology to generate thicker and high-quality films than natural oxide films by treating metals via electrochemical methods. Electrochemical manufacturing method of nano structure is an efficient technology in terms of cost reduction, high productivity and complicated shapes, which receives the spotlight in diverse areas. Especially, artificial films generated by anodizing technology possess excellent mechanical characteristics including hardness and wear resistance. It is also easy to modify thickness and adjust shape of those artificial films so that they are mainly used in sensors, filters, optical films and electrolytic condensers. In this study, experiment was performed to observe the effect of current density on porous film formation in two-step anodizing for Al alloy. Anodizing process was performed with 10 vol.% sulfuric acid electrolyte while the temperature was maintained at $10^{\circ}C$ using a double beaker. and $10{\sim}30mA/cm^2$ was applied for 40 minutes using a galvanostatic method. As a result, both pore diameters and distances between pores tended to increase as the local temperature and electrolysis activity increased due to the increase in applied current density.

Keywords

References

  1. S. M. Moon, C. N. Yang, S. J. Na, Formation Behavior of Anodic Oxide Films on Al7075 Alloy in Sulfuric Acid Solution, J. Kor. Inst. Surf. Eng., 47 (2014) 155-161. https://doi.org/10.5695/JKISE.2014.47.4.155
  2. F. Keller, M. S. Hunter, D. L. Robinson, Structural Features of Oxide Coatings on Aluminum, J. Electrochem. Soc., 100 (1953) 411-419. https://doi.org/10.1149/1.2781142
  3. H. Masuda, K. Fukuda, Ordered Metal Nanohole Arrays Made by a Two-step Replication of Honeycomb Structures of Anodic Alumina, Science, 268 (1995) 1466-1468. https://doi.org/10.1126/science.268.5216.1466
  4. J. S. Jo, J. H. Kim, S. W. Ko, S. M. Lim, Heat Dissipation of $Al_2O_3$ Insulation Layer Prepared by Anodizing Process for Metal PCB, J. Korean Inst. Surf. Eng., 48 (2015) 33-37. https://doi.org/10.5695/JKISE.2015.48.2.33
  5. I. J. Son, Effect of Equal Channel Angular Pressing on the Pitting Corrosion Resistance of Hard Anodized Al5052 Alloy, J. Korean Inst. Surf. Eng., 48 (2015) 142-148. https://doi.org/10.5695/JKISE.2015.48.4.142
  6. S. Y. Kang, D. W. Lee, Study on Improvement of Corrosion Resistance and Wear Resistance by Anodizing and Sealing Treatment with Nanodiamond Powder on aluminum, J. Korean Inst. Surf. Eng., 47 (2014) 121-127. https://doi.org/10.5695/JKISE.2014.47.3.121
  7. G. E. Thompson, G. C. Wood, Corrosion: Aqueous Process and Passive Films, J. C. Scully, Academic Press, London, (1982) 205.
  8. Y. H. Chang, C. W. Lee, Y. M. Hahm, Preparation of Porous Alumina Membrane by Anodic Oxidation in Sulfuric Acid, Korean J. Chem. Eng., 36 (1998) 653-660.
  9. C. E. Michelson, The Current-Voltage Characteristics of Porous Anodic Oxides on Aluminum, J. Electrochem. Soc., 115 (1968) 213-219. https://doi.org/10.1149/1.2411088
  10. T. A. Renshaw, A Study of Pore Structures on Anodized Aluminum, J. Electrochem. Soc., 108 (1961) 185-191. https://doi.org/10.1149/1.2428038
  11. Y. C. Kim, Y. S. Jeong, Surface Treatment of Aluminium by Anodizing, Prospectives of Industrial Chemistry, 2 (1999) 3-10.
  12. E. K. Joo, S. S. Kim, H. J. Oh, C. S. Chi, Effects of Hydration Treatments on the Phase Transition of Anodic Aluminum Oxide Layers, Korean J. Mater. Res., 12 (2002) 540-544. https://doi.org/10.3740/MRSK.2002.12.7.540
  13. S. K. Kim, Effects of Additives on The Formation of Etch-Pit of Pure Al and Analysis on Dielectric Films Formed by Anodizing, Ph.D. diss., Kookmin University, Seoul, (2000) 46.
  14. J. S. Choi, J. W. Lee, J. H. Lim, S. J. Kim, Technology Trends in Fabrication of Nanostructures of Metal Oxides by Anodization and Their Applications, Ind. Eng. Chem., 19 (2008) 249-258.
  15. V. F. Henley, Anodic oxidation of aluminum and its alloys, 1st eds., Pergamon Press, New-York (1982) 124.
  16. S. Park, T. Kang, The Mechanism of The Formation of An Anodic Oxide Layer on The Aluminium, J. Kor. Inst. Surf. Eng., 12 (1979) 167-173.
  17. D. N. Lee, J. H. Lee, I. K. Kang, The Structure of Porous Anodic Oxide Films on Aluminum, Korean J. Met. Mater., 11 (1973) 34-354.
  18. T. P. Hoar, J. Yahalom, The Initiation of Pores in Anodic Oxide Films Formed on Aluminum in Acid Solutions, J. Electrochem. Soc., 110 (1963) 614-621. https://doi.org/10.1149/1.2425839