Journal of Magnesium and Alloys (2020-03-01)

Active corrosion protection of super-hydrophobic corrosion inhibitor intercalated Mg–Al layered double hydroxide coating on AZ31 magnesium alloy

  • Xin Wang,
  • Chuan Jing,
  • Yuxiang Chen,
  • Xiushuang Wang,
  • Gang Zhao,
  • Xing Zhang,
  • Liang Wu,
  • Xiaoying Liu,
  • Biqin Dong,
  • Yuxin Zhang

Journal volume & issue
Vol. 8, no. 1
pp. 291 – 300

Abstract

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Magnesium alloys, the advanced lightweight structural materials, have been successfully applied in the manufacturing field. Unfortunately, their poor corrosion resistance restrains the potential wide applications. In this work, anti-corrosion coatings were fabricated via the in-situ growth of the corrosion inhibitors intercalated magnesium-aluminum layered double hydroxide (Mg–Al LDH) on AZ31 magnesium alloy and then post-sealing it by a super-hydrophobic coating. SEM, XRD, EDS, FTIR, XPS and contact angle test were conducted to analyze physical/chemical features of these coatings. Potentiodynamic polarization curves and electrochemical impedance spectroscopy were recorded to assess the anti-corrosion performance of prepared coatings. Surprisingly, Mg–Al LDH with molybdate intercalation and lauric acid modification achieves the excellent corrosion inhibition performance (99.99%) due to the multicomponent synergistic effect such as the physical protection of Mg–Al LDH, the corrosion inhibition of molybdate and super-hydrophobic properties of lauric acid. This work presents a scientific perspective and novel design philosophy to fabricate the efficient anti-corrosion coating to protect magnesium alloys and then expand their potential applications in other field. Keywords: Magnesium alloy, Superhydrophobicity, LDH films, Corrosion inhibitor, Corrosion resistance