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Vol.48, No.8, 724 ~ 730, 2010
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| Title |
| Effect of Potassium Permanganate on Corrosion Behavior of Magnesium Alloy Prepared by Micro-Arc Oxidation |
| 고영건 Young Gun Ko , 이강민 Kang Min Lee , 신기룡 Ki Ryong Shin , 신동혁 Dong Hyuk Shin |
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| Abstract |
| The effect of potassium permanganate (KMnO4) in an electrolyte on the corrosion performance of magnesium alloy coated by micro-arc oxidation (MAO) has been investigated in this study. For this purpose, MAO coating was carried out on the present sample under AC condition in an alkaline silicate electrolyte with and without KMnO4. Irrespective of the addition of KMnO4, it was found from structural observation that the ceramic coating layers consisted of inner and outer layers. In the sample processed in the electrolyte with KMnO4, the outer layer became dense and even contained a number of Mn2O3 atoms, resulting in high corrosion resistance. Based on the results of a potentiodynamic polarization test, it was confirmed that the coating layer formed in the electrolyte with KMnO4 exhibited better corrosion resistance than that without KMnO4. The high corrosion resistance of the MAO-treated magnesium alloy was explained in relation to the equivalent circuit model. |
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| Key Words |
| alloys, coating, corrosion, scanning electron microscopy, SEM, electrochemiacl analysis |
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