Effect of current density on wettability and corrosion resistance of superhydrophobic nickel coating deposited on low carbon steel

In this study, nickel coating was electrodeposited on low carbon steel (LCS) surface. The effect of current density on surface morphology, crystal orientation and wettability of nickel coatings were comparatively studied. The abrasive resistance of coatings was carried out by self-made equipment. Moreover, the corrosion resistance of the surfaces was investigated by potentiodynamic polarization curves as well as electrochemical impedance spectroscopy (EIS) in the corrosive medium of 3.5 wt.% NaCl solution. The results showed that the surfaces present a micro-nano structure at the current density of 6 A/dm(2) and 8 A/dm(2), and exhibit superhydrophobicity after modification with myristic acid. The crystal orientation changed with the variation of current densities. It is worth noting that the surface deposited at 6 A/dm(2) showed excellent mechanical stability after abraded by sandpaper for 10 times with interesting bouncing behavior. Moreover, electrochemical measurements showed that the corrosion potential (E-corr) of superhydrophobic surface was ascended from -0.447 V to -0.186 V, and the EIS value was up to 1.04x 10(5) Omega cm(2), indicating excellent corrosion resistance. The corrosion mechanism is illuminated via equivalent circuits. (C) 2016 Elsevier Ltd. All rights reserved.