Duplex surface modification combined with micro-arc oxidation and polymer plating on AZ31 magnesium alloy and their functional properties

作者：Lai, Xiao-Ming; Kang, Zhi-Xin^*; Li, Yuan-Yuan

来源：Chinese Journal of Nonferrous Metals, 2011, 21(6): 1299-1307.

• Corrosion current densities
• Electrochemical reactions
• Hydrophobic
• Microarc oxidation
• Polymer plating
• Super-hydrophilic
• Surface modification methods
• Three orders of magnitude

A duplex surface modification method combined with micro-arc oxidation (MAO) and developed polymer plating was applied to AZ31 magnesium alloy. The growth and surface morphology of MAO-modified film, electrochemical reaction process during polymer plating on MAO-modified film surface, wettability and corrosion behaviors of MAO-modified film and duplex-modified film were researched. The results show that a superhydrophilic surface is fabricated after MAO modification and its contact angle (CA) of distilled water is almost 0, because Van der Waals force and capillary suction effect are relatively strong contacted with the distilled water when MAO-modified surface formed with micro- and nano-porous rough structures, moreover, MAO-modified film with high surface free energy and high polar component have very strong intermiscibility to strong-polar water molecules. However, the alteration from superhydrophilic to hydrophobic surface with contact angle of 113.7° is realized by duplex modification of polymer plating on MAO-modified film surface due to repelling interaction between the strong-polar water molecules and duplex-modified surface with low surface free energy. The corrosion resistance has been greatly improved by duplex modification of polymer plating on the MAO-modified film surface. Compared with bare magnesium alloy, the corrosion current density of hydrophobic duplex-modified film from potentiodynamic polarization decreases by three orders of magnitude, while the electrochemical impedance from electrochemical impedance spectroscopy increases by three orders of magnitude as the duplex-modified film presents similar to pure capacitance behavior in 0.1 mol/L NaCl solution.

• 出版日期2011-6
• 单位华南理工大学