Obtaining and characterization of super-hydrophobic nickel coatings applied on ASTM A36 carbon steel via electrodeposition as an alternative for anticorrosive protection

The present study aimed to develop and characterize super-hydrophobic nickel coatings through the electrodeposition process, employing myristic acid as a surface energy reducing agent, with the objective of enhancing corrosion resistance. ASTM A36 carbon steel (E00) specimens served as substrates for the application of three different coating conditions: pure nickel (E10); nickel associated with myristic acid (E01); and a bilayer structure consisting of a base layer of pure nickel succeeded by an additional layer of nickel enriched with myristic acid (E11). The samples were characterized through Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). Corrosion resistance of the coatings was analyzed through potentiodynamic polarization (PP) tests and electrochemical impedance spectroscopy (EIS). XRD and FTIR tests confirmed the deposition of metallic nickel onto the substrate and the successful incorporation of the surface energy reducing agent. Micrographs illustrated the distinctive cauliflower-like clusters in the E11 coating, denoting its pronounced superhydrophobic characteristics, culminating in a contact angle of 165 °. Corrosion tests demonstrated superior anticorrosive behavior in the E11 sample, as evidenced by a heightened corrosion potential, diminished anodic current density, and an augmented impedance modulus. The results emphasize the role of superhydrophobicity in influencing the corrosion resistance of the developed coatings. (author)