Electrochemical and hydrodynamic flow characterization of corrosion protection persistence of nickel/multiwalled carbon nanotubes composite coating

Abstract Nickel/multiwalled carbon nanotubes (Ni-MWCNTs) composite coatings have been reported to exhibit corrosion protection. A number of works in the literature have investigated the application of this nanocomposite in the protection of different metals under static conditions. The present work investigates the persistence (integrity) and overall effectiveness of Ni-MWCNTs on mild steel through electrochemical methods and hydrodynamic flow. Ni-MWCNTs were prepared in a modified watts type electrolyte and tested for corrosion protection of mild steel in a static and flow media containing 3.5% NaCl electrolyte. The electrochemical impedance, potentiodynamic polarization, and weight loss measurements were all made to find the corrosion behavior of the composite coatings with respect to time on the metal surface. The electrochemical studies revealed higher resistance of the composites to corrosion with extended service life compared to nickel coating alone on steel. The surface morphology and microstructure of the coatings were investigated by field emission scanning electron microscope (FE-SEM) and other complementary techniques.