Fig. 1. Voltage-time curves as a function of the concentration of Na3PO4.
Fig. 2. Top view FE-SEM images of PEO coatings; (a) 3 g L-1, (b) 6 g L-1, (c) 9 g L-1, and (d) 12 g L-1. (e) Variation of the porosity and the conductivity in different electrolytes.
Fig. 3. Top and cross-sectional view FE-SEM images of PEO coatings; (a), (b) before and (c), (d) after NaAlO2 sealing
Fig. 4. XRD patterns before and after NaAlO2 sealing.
Fig. 5. Potentiodynamic polarization curves before and after NaAlO2 sealing in 0.6 M NaCl solution.
Table 1. The parameters derived from the potentiodynamic polarization curves.
참고문헌
- J.H. Wang, M.H. Du, F.Zh. Han, J. Yang, Effects of the Ratio of Anodic and Cathodic Currents on the Characteristics of Micro-arc Oxidation Ceramic Coatings on Al Alloys, Appl. Surf. Sci. 292 (2014) 658-664. https://doi.org/10.1016/j.apsusc.2013.12.028
- V. Dehnavi, B.L. Luan, D.W. Shoesmith, X.Y. Liu, S. Rohani, Effect of Duty Cycle and Applied Current Frequency on Plasma Electrolytic Oxidation (PEO) Coating Growth Behavior, Surf. Coat. Techno. 226 (2013) 100-107. https://doi.org/10.1016/j.surfcoat.2013.03.041
-
V. Shoaei-Rad, M.R. Bayati, H.R. Zargar, J. Javadpour, F. Golestani-Fard, In Situ Growth of
$ZrO_2$ -$Al_2O_3$ Nano-crystalline Ceramic Coatings Via Micro Arc Oxidation of Aluminum Substrates, Mater. Res. Bull. 47 (2012) 1494-1499. https://doi.org/10.1016/j.materresbull.2012.02.031 - M. Vakili-Azghandi, A.Fattah-alhosseini, Effects of Duty Cycle, Current Frequency, and Current Density on Corrosion Behavior of the Plasma Electrolytic Oxidation Coatings on 6061 Al Alloy in Artificial Seawater, Metall. Mater. Tran. A 48 (2017) 4681-4692. https://doi.org/10.1007/s11661-017-4205-8
- C.M. Abreu, M.J. Cristobal, R. Figueroa, G. Pena, Wear and corrosion performance of two different tempers (T6 and T73) of AA7075 aluminium alloy after nitrogen implantation, Appl. Surf. Sci. 327 (2015) 51-61. https://doi.org/10.1016/j.apsusc.2014.11.111
- I. Recloux, M. Mouganga, M. Druart, Y. Paint, M.G. Olivier, Silica mesoporous thin films as containers for benzotriazole for corrosion protection of 2024 aluminium alloys, Appl. Surf. Sci. 346 (2015) 124-133. https://doi.org/10.1016/j.apsusc.2015.03.191
- M. Sabaghi Joni, A. Fattah-alhosseini, Effect of KOH Concentration on the Electrochemical Behavior of Coatings Formed by Pulsed DC Microarc Oxidation (MAO) on AZ31B Mg Alloy, J. Alloys Compd. 661 (2016) 237-244. https://doi.org/10.1016/j.jallcom.2015.11.169
- X. Wu, W. Qin, Y. Guo, Zh. Xie, Self-Lubricative Coating Grown by Micro-plasma Oxidation on Aluminum Alloys in the Solution of Aluminate-Graphite, Appl. Surf. Sci. 254 (2008) 6395-6399. https://doi.org/10.1016/j.apsusc.2008.04.001
- S. Moon, Anodic Oxidation Treatment Methods of Metals, J. Korean Inst. Suf. Eng., 51 (2018)
-
J. Liang, P.B. Srinivasan, C. Blawert, W. dietzel, Comparison of electrochemical corrosion behaviour of MgO and
$ZrO_2$ coatings on AA50 magnesium alloy formed by plasma electrolytic oxidation Corros. Sci. 51 (2009) 2483-2492. - F. Liu, D.Y. Shan, Y.W. Song, E.H. Han, W. Ke, Corrosion behavior of the composite ceramic coating containing zirconium oxides on AM30 magnesium alloy by plasma electrolytic oxdiation, Corros. Sci. 53 (2011) 3845-3852. https://doi.org/10.1016/j.corsci.2011.07.037
- N. Kim, S. Park, K. Park, J. Choi, Surface Morphological Properties of Micro-arc Oxidation Coating on Al6061 Alloys using Unipolar Pulse, J. Korean Inst. Suf. Eng., 50 (2017) 421-426
- J. Lee, S. Kim, Characterization of Ceramic Oxide Layer Produced on Commercial Al alloy by Plasma Electrolytic Oxidation in Various KOH Concentrations, J. Korean Inst. Suf. Eng., 49 (2016) 119-124 https://doi.org/10.5695/JKISE.2016.49.2.119
- J. Lee, S. Kim, Influences of Potassium Fluoride (KF) Addition on the Surface Characteristics in Plasma Electrolytic Oxidation of Marine Grade Al Alloy, J. Korean Inst. Suf. Eng., 49 (2016) 280-285 https://doi.org/10.5695/JKISE.2016.49.3.280
- S. Moon, Y. Kim, Lateral growth of PEO films on Al1050 alloy in an alkaline electrolyte, J. Korean Inst. Suf. Eng., 50 (2017) 10-16 https://doi.org/10.5695/JKISE.2017.50.1.10
- S. Moon, Y. Kim, PEO film formation behavior of Al1050 alloy under direct current in an alkaline electrolyte, J. Korean Inst. Suf. Eng., 50 (2017) 17-23 https://doi.org/10.5695/JKISE.2017.50.1.17
-
Z.U. Rehman, S.H. Shin, M. Kaseem, M. Uzair, B.H. Koo, Towards a compact coating formed on Al6061 alloy in phosphate based electrolyte via two-step PEO process and
$K_2ZrF_6$ additives, Surf. Coat., 328 (2017) 355-360 https://doi.org/10.1016/j.surfcoat.2017.09.013 - A. Fattah-alhosseini, S.O. Gashti, M. Molaie, Effects of Disodium Phosphate Concetration (Na2HPO4.2H2O) on Microstructure and Corrosion Resistance of Plasma Electrolytic Oxidation (PEO) Coatings on 2024 Al Alloy, J. Mater. Eng. Perform., 27 (2018) 825-834 https://doi.org/10.1007/s11665-018-3124-1
-
S. Fatimah, M.P. Kamil, J.H. Kwon, M. Kaseem, Y.G. Ko, Dual incorporation of
$SiO_2$ and$ZrO_2$ nanoparticles into the oxide layer on 6061 Al alloy via plasma electrolytic oxidation: Coating structure and corrosion properties, J. Alloys Compd. xxx (2016) 1-7. - Z. Li, X. Jing, Y. Yuan, M. Zhang, Composite coatings on a Mg-Li alloy prepared by combined plasma electrolytic oxidation and sol-gel techniques, Corros. Sci. 63 (2012) 358-366. https://doi.org/10.1016/j.corsci.2012.06.018
- N. Barati, A. Yerokhin, F. Golestanifard, S. Rastegari, E.I. Meletis, Alumina-zirconia coatings produced by Plasma Electrolytic Oxidation on Al alloy for corrosion resistance improvement, J. Alloys Compd. 724 (2017) 435-442. https://doi.org/10.1016/j.jallcom.2017.07.058
- M. Shokouhfar, C. Dehghanian, M. Montazeri, A. Baradaran, Preparation of Ceramic Coating on Ti Substrate by Plasma Electrolytic Oxidation in Different Electrolytes and Evaluation of Its Corrosion Resistance: Part II, Appl. Surf. Sci. 258 (2012) 2416-2423. https://doi.org/10.1016/j.apsusc.2011.10.064
-
M. Kim, H. Yoo, J. Choi, Non-nickel-based sealing of anodic porous aluminum oxide in
$NaAlO_2$ , Surf. Coat. 310 (2017) 106-112. https://doi.org/10.1016/j.surfcoat.2016.11.100 - M. Kaseem, M.P. Kamil, J.H. Kown, Y.G. Ko, Effect of sodium benzoate on corrosion behavior of 6061 Al alloy processed by plasma electrolytic oxidation, Surf. Coat. 283 (2015) 268-273. https://doi.org/10.1016/j.surfcoat.2015.11.006
- M. Stern, A.L. Geary, A theoretical analysis of the shape of polarization curves, J. Electrochem. Soc. 104 (1957) 56-63. https://doi.org/10.1149/1.2428496
-
D. Galuskova, Corrosion of structural ceramics under sub-critical conditions in aqueous sodium chloride solution and in deionized water. Part II: dissolution of
$Al_2O_3$ -Based ceramics, J. Am. Ceram. Soc. 94 (2011) 3044-3052. https://doi.org/10.1111/j.1551-2916.2011.04513.x