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Characterization of Ceramic Oxide Layer Produced on Commercial Al Alloy by Plasma Electrolytic Oxidation in Various KOH Concentrations
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 Title & Authors
Characterization of Ceramic Oxide Layer Produced on Commercial Al Alloy by Plasma Electrolytic Oxidation in Various KOH Concentrations
Lee, Jung-Hyung; Kim, Seong-Jong;
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 Abstract
Plasma electrolytic oxidation (PEO) is a promising coating process to produce ceramic oxide on valve metals such as Al, Mg and Ti. The PEO coating is carried out with a dilute alkaline electrolyte solution using a similar technique to conventional anodizing. The coating process involves multiple process parameters which can influence the surface properties of the resultant coating, including power mode, electrolyte solution, substrate, and process time. In this study, ceramic oxide coatings were prepared on commercial Al alloy in electrolytes with different KOH concentrations (0.5 ~ 4 g/L) by plasma electrolytic oxidation. Microstructural and electrochemical characterization were conducted to investigate the effects of electrolyte concentration on the microstructure and electrochemical characteristics of PEO coating. It was revealed that KOH concentration exert a great influence not only on voltage-time responses during PEO process but also on surface morphology of the coating. In the voltage-time response, the dielectric breakdown voltage tended to decrease with increasing KOH concentration, possibly due to difference in solution conductivity. The surface morphology was pancake-like with lower KOH concentration, while a mixed form of reticulate and pancake structures was observed for higher KOH concentration. The KOH concentration was found to have little effect on the electrochemical characteristics of coating, although PEO treatment improved the corrosion resistance of the substrate material significantly.
 Keywords
Plasma electrolytic oxidation (PEO);Ceramic;Al alloy;Electrolyte concentration;
 Language
English
 Cited by
1.
Influences of Potassium Fluoride (KF) Addition on the Surface Characteristics in Plasma Electrolytic Oxidation of Marine Grade Al Alloy, Journal of the Korean institute of surface engineering, 2016, 49, 3, 280  crossref(new windwow)
 References
1.
D. Kwon, S. Moon, Effects of NaOH Concentration on the Structure of PEO Films Formed on AZ31 Mg Alloy in ${PO_4}^{3-}$ and ${SiO_3}^{2-}$ Containing Aqueous Solution, J. Kor. Inst. Surf. Eng. 49 (2016) 46-53. crossref(new window)

2.
S. Ikonopisov, Theory of electrical breakdown during formation of barrier anodic films, Electrochim. Acta, 22 (1977) 1077-1082. crossref(new window)

3.
A. L. Yerokhin, X. Nie, A. Leyland, A. Matthews, and S.J. Dowey, Plasma electrolysis for surface engineering, Surf. Coat. Technol., 122 (1999) 73-93. crossref(new window)

4.
L. O. Snizhko, A. L. Yerokhin, A. Pilkington, N. L. Gurevina, D. O. Misnyankin, A. Leyland, A. Matthews, Anodic processes in plasma electrolytic oxidation of aluminium in alkaline solutions, Electrochim. Acta, 49 (2004) 2085-2095. crossref(new window)

5.
J. Liang, B. Guo, J. Tian, H. Liu, Zhou, J., and T. Xu, Effect of potassium fluoride in electrolytic solution on the structure and properties of microarc oxidation coatings on magnesium alloy, Appl. Surf. Sci., 252 (2005) 345-351. crossref(new window)

6.
W. Li, L. Zhu, H. Liu, Effects of silicate concentration on anodic films formed on AZ91D magnesium alloy in solution containing silica sol, Surf. Coat. Technol., 201 (2006) 2505-2511. crossref(new window)

7.
E. Matykina, A. Berkani, P. Skeldon, G. E. Thompson, Real-time imaging of coating growth during plasma electrolytic oxidation of titanium, Electrochim. Acta, 53 (2007) 1987-1994. crossref(new window)

8.
K. C. Kalra, K. C. Singh, M. Singh, Electrical breakdown of anodic films on titanium in aqueous electrolytes, J. Electroanal. Chem., 371 (1994) 73-78. crossref(new window)

9.
R. O. Hussein, D. O. Northwood, and X. Nie, Coating growth behavior during the plasma electrolytic oxidation process, J. Vac. Sci. Technol. A, 28 (2010) 766-773. crossref(new window)

10.
J. A. Curran, T. W. Clyne, Porosity in plasma electrolytic oxide coatings, Acta Mater., 54 (2006) 1985-1993. crossref(new window)

11.
E. I. Meletis, X. Nie, F. L. Wang, J. C. Jiang, Electrolytic Plasma Processing for Cleaning and Metal-coating of Steel Surface, Surf. Coat. Technol., 150 (2002) 246-256. crossref(new window)

12.
R. C. Barik, J. A. Wharton, R. J. K. Wood, K. R. Stokes, R. L. Jones, Corrosion, erosion and erosion-corrosion performance of plasma electrolytic oxidation (PEO) deposited $Al_2O_3$ coatings, Surf. Coat. Technol., 199 (2005) 158-167. crossref(new window)

13.
H. Duan, C. Yan, F. Wang, Effect of electrolyte additives on performance of plasma electrolytic oxidation films formed on magnesium alloy AZ91D, Electrochim. Acta, 52 (2007) 3785-3793. crossref(new window)

14.
P. Bala Srinivasan, J. Liang, C. Blawert, M. Stormer, W. Dietzel, Effect of current density on the microstructure and corrosion behaviour of plasma electrolytic oxidation treated AM50 magnesium alloy, Appl. Surf. Sci., 255 (2009) 4212-4218. crossref(new window)

15.
J. B. Bajat, R. Vasilic, S. Stojadinovic, V. Miskovic-Stankovic, Corrosion Stability of Oxide Coatings Formed by Plasma Electrolytic Oxidation of Aluminum: Optimization of Process Time, Corrosion, 69 (2013) 693-702. crossref(new window)