Reinforced adhesion by in-situ growth converse chemical layers between substrates and electrosprayed organic coatings to improve anti-corrosion of magnesium alloy

In this paper, layered double hydroxide (LDH) layers by in situ grown from magnesium alloy, and then fluororesin hydrophobic coatings that deposited by the following electrospraying onto were fabricated to improve the corrosion resistances of substrate. The weak adhesion that usually existed between the organic coatings with active alloy substrate, and the limited corrosion resistance of LDH layers due to its original surfacial micropores and defects, could be well conquered and thus the anti-corrosion performances could be enhanced effectively. Using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), the anti-corrosion abilities of the composite coatings were detected and evaluated in details. And the results showed that, owing to the compactness interlocked by the in situ grown intermediate layers, and the obvious hydrophobicities of the coatings, the composite coatings contribute relative excellent corrosion resistance to the substrate. In addition, it was showed by the scratched grid test, due to the abundant hydroxyl groups and the coarse surfacial structures given by the intermediate LDH layers, there occurred obvious bonding interactions between the coatings and the substrates. So the present work gave a potential and valid strategy to fabricate composite anti-corrosion coatings onto metallic substrates.