Evaluation of microstructural effects on corrosion behavior of AZ31B magnesium alloy with a MAO coating and electroless Ni-P plating
A bi-layer coating is deposited on the surface of the AZ31B Mg alloy for corrosion protection of the Mg alloy. The bi-layer coating is composed of a micro-arc oxidation coating (MAO), and an electroless plated Ni-P coating. The micro-arc oxidation (MAO) treatment in the electrolyte with or without t...
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| Format: | Article |
| Language: | English |
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Elsevier
2020-11-01
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| Series: | Journal of Materials Research and Technology |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S223878542031824X |
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| author | Chi-An Chen Shun-Yi Jian Chia-Hsin Lu Chia-Yu Lee Salim Levent Aktuğ Ming-Der Ger |
| author_facet | Chi-An Chen Shun-Yi Jian Chia-Hsin Lu Chia-Yu Lee Salim Levent Aktuğ Ming-Der Ger |
| author_sort | Chi-An Chen |
| collection | DOAJ |
| description | A bi-layer coating is deposited on the surface of the AZ31B Mg alloy for corrosion protection of the Mg alloy. The bi-layer coating is composed of a micro-arc oxidation coating (MAO), and an electroless plated Ni-P coating. The micro-arc oxidation (MAO) treatment in the electrolyte with or without the addition of phosphate ions is carried out under unipolar power mode. The microstructure and composition of the MAO coatings are analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The roughness of the MAO coatings is obtained by using 3D white light interferometry. The corrosion resistances are evaluated by potentiodynamic polarization test as well as electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution and salt spray test. The adhesion test results of the MAO/Ni-P composite coatings by drawing test machine. The results showed that the micro-pores size of the MAO coating treated in the phosphate-free bath is uniform and smaller than the phosphate-containing solution, which could decrease the roughness and enhance the corrosion resistance. The corrosion resistance of MAO coating with the phosphate-free solution for 2.8 times was better than that of phosphate-containing solution. Moreover, phosphate-free MAO/Ni-P composite coating showed the corrosion rate is more than 4 times lower than the phosphate-containing MAO/Ni-P composite coating. Furthermore, the MAO/Ni-P composite coatings prepared by the MAO coating treated in the phosphate-free bath could suppress the erosion of aggressive media during exposure after 120 h salt spray test (corrosion area is approximately 5%) and present excellent adhesion. |
| first_indexed | 2024-12-13T11:44:11Z |
| format | Article |
| id | doaj.art-2944cbbfcc874b999f058f585b577e37 |
| institution | Directory Open Access Journal |
| issn | 2238-7854 |
| language | English |
| last_indexed | 2024-12-13T11:44:11Z |
| publishDate | 2020-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj.art-2944cbbfcc874b999f058f585b577e372022-12-21T23:47:33ZengElsevierJournal of Materials Research and Technology2238-78542020-11-01961390213913Evaluation of microstructural effects on corrosion behavior of AZ31B magnesium alloy with a MAO coating and electroless Ni-P platingChi-An Chen0Shun-Yi Jian1Chia-Hsin Lu2Chia-Yu Lee3Salim Levent Aktuğ4Ming-Der Ger5Graduate School of Defense Science, Chung Cheng Institute of Technology, National Defense University, Taoyuan, TaiwanDepartment of Chemical & Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Taoyuan, Taiwan; System Engineering and Technology Program, National Chiao Tung University, Hsin-Chu, Taiwan; Corresponding author.Department of Chemical & Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Taoyuan, TaiwanDepartment of Chemical & Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Taoyuan, TaiwanDepartment of Materials Science and Engineering, Gebze Technical University, Gebze, KocaeliDepartment of Chemical & Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Taoyuan, Taiwan; System Engineering and Technology Program, National Chiao Tung University, Hsin-Chu, Taiwan; Corresponding author.A bi-layer coating is deposited on the surface of the AZ31B Mg alloy for corrosion protection of the Mg alloy. The bi-layer coating is composed of a micro-arc oxidation coating (MAO), and an electroless plated Ni-P coating. The micro-arc oxidation (MAO) treatment in the electrolyte with or without the addition of phosphate ions is carried out under unipolar power mode. The microstructure and composition of the MAO coatings are analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The roughness of the MAO coatings is obtained by using 3D white light interferometry. The corrosion resistances are evaluated by potentiodynamic polarization test as well as electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution and salt spray test. The adhesion test results of the MAO/Ni-P composite coatings by drawing test machine. The results showed that the micro-pores size of the MAO coating treated in the phosphate-free bath is uniform and smaller than the phosphate-containing solution, which could decrease the roughness and enhance the corrosion resistance. The corrosion resistance of MAO coating with the phosphate-free solution for 2.8 times was better than that of phosphate-containing solution. Moreover, phosphate-free MAO/Ni-P composite coating showed the corrosion rate is more than 4 times lower than the phosphate-containing MAO/Ni-P composite coating. Furthermore, the MAO/Ni-P composite coatings prepared by the MAO coating treated in the phosphate-free bath could suppress the erosion of aggressive media during exposure after 120 h salt spray test (corrosion area is approximately 5%) and present excellent adhesion.http://www.sciencedirect.com/science/article/pii/S223878542031824XAZ31B magnesium alloyMAOElectroless Ni-P platingAdhesionCorrosion resistance |
| spellingShingle | Chi-An Chen Shun-Yi Jian Chia-Hsin Lu Chia-Yu Lee Salim Levent Aktuğ Ming-Der Ger Evaluation of microstructural effects on corrosion behavior of AZ31B magnesium alloy with a MAO coating and electroless Ni-P plating Journal of Materials Research and Technology AZ31B magnesium alloy MAO Electroless Ni-P plating Adhesion Corrosion resistance |
| title | Evaluation of microstructural effects on corrosion behavior of AZ31B magnesium alloy with a MAO coating and electroless Ni-P plating |
| title_full | Evaluation of microstructural effects on corrosion behavior of AZ31B magnesium alloy with a MAO coating and electroless Ni-P plating |
| title_fullStr | Evaluation of microstructural effects on corrosion behavior of AZ31B magnesium alloy with a MAO coating and electroless Ni-P plating |
| title_full_unstemmed | Evaluation of microstructural effects on corrosion behavior of AZ31B magnesium alloy with a MAO coating and electroless Ni-P plating |
| title_short | Evaluation of microstructural effects on corrosion behavior of AZ31B magnesium alloy with a MAO coating and electroless Ni-P plating |
| title_sort | evaluation of microstructural effects on corrosion behavior of az31b magnesium alloy with a mao coating and electroless ni p plating |
| topic | AZ31B magnesium alloy MAO Electroless Ni-P plating Adhesion Corrosion resistance |
| url | http://www.sciencedirect.com/science/article/pii/S223878542031824X |
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