Using Post-supercritical CO2-assisted Method to Deposit NieP Alloy Coating on the Micro-arc Oxidation Layer of AZ31 Magnesium Alloy and its Corrosion Behavior Analysis

Authors

Kang-Yu Liao, Department of Mechanical Engineering, Lunghwa University of Science and Technology, Guishan, Taoyuan 335, Taiwan
Hung-Hua Sheu, Department of Mechanical Engineering, Lunghwa University of Science and Technology, Guishan, Taoyuan 335, TaiwanFollow
Ming-Yuan Lin, Department of Mechanical Engineering, Army Academy, Chung-Li, Taoyuan, 320, Taiwan
Ming-Chih Kuo, Department of Textile Engineering, Chinese Culture University, Yang-Ming-Shan, Taipei, 111 Taiwan
Po-Hsun Wu, Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 202, Taiwan
Hung-Bin Lee, Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 202, TaiwanFollow

Abstract

In this study, a Ni-P alloy coating was deposited on the micro arc oxidation (MAO) layer of AZ31 magnesium alloy to improve its corrosion resistance. The MAO layers were prepared under different operated voltages from 300 to 400 V. The results indicated that the optimize operated parameters for MAO layer is at 350 V, the MAO coatings had the most compact microstructure and superior corrosion resistance. In order to improve the corrosion resistance of MAO coating, this study chose to deposit Ni-P alloy coating on the surface of MAO coating via the post supercritical CO₂-assisted electroless plating (PSC-CO₂-EP) process. The results presented that a MAO/Ag/PSC-CO₂-NiP sandwich-structured composite coating was successfully prepared and had the best corrosion resistance which i_corr value is approximately at 8.60×10^-7 A/cm². Moreover, the results of the alternating hot and cold salt spray test in seawater showed that cracks appeared in the coating, and corrosion products could be observed at the crack interface, which indicated that the coating had a corrosion reaction.

Recommended Citation

Liao, Kang-Yu; Sheu, Hung-Hua; Lin, Ming-Yuan; Kuo, Ming-Chih; Wu, Po-Hsun; and Lee, Hung-Bin (2025) "Using Post-supercritical CO2-assisted Method to Deposit NieP Alloy Coating on the Micro-arc Oxidation Layer of AZ31 Magnesium Alloy and its Corrosion Behavior Analysis," Journal of Marine Science and Technology: Vol. 33: Iss. 1, Article 7.
DOI: 10.51400/2709-6998.2766
Available at: https://jmstt.ntou.edu.tw/journal/vol33/iss1/7