Corrosion Behavior of Ni/NiCr/NiCrAlSi Composite Coating on Copper for Application as a Heat Exchanger in Sea Water

Abstract

This study introduces a novel Ni/NiCr/NiCrAlSi composite coating to enhance the corrosion resistance of copper, particularly for its use in marine heat exchangers. Utilizing characterization techniques such as scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS), the paper investigates the coating’s composition, structure, and corrosion resistance in 3.5 wt.% NaCl aqueous solutions. A significant focus is placed on the role of aluminum within the NiCrAlSi layer, examining its influence on the coating’s structure and corrosion behavior. The results indicate that the NiCrAlSi layer with an aluminum content of 5.49 at.% exhibits the most improved corrosion resistance, characterized by the highest corrosion potential and a corrosion current density that is more than one order of magnitude lower compared to the Ni/NiCr coating. The effectiveness of this composite coating is attributed to its multilayer structure and the synergistic effect of alloying elements Cr, Al, and Si, which collectively inhibit corrosive medium penetration. These insights present the Ni/NiCr/NiCrAlSi coating as a promising candidate for copper protection in sea water environments, merging enhanced durability with cost-effectiveness.

Effect of Cetyl Pyridinium Chloride on Corrosion Inhibition Properties of Mild Steel in Acidic Medium

“…The majority of these compounds have demonstrated mixed-type corrosion inhibition in acidic solutions, protecting mild steel. Benzothiazoles have been employed as corrosion inhibitors for copper and steel [11].…”

Effect of Cetyl Pyridinium Chloride on Corrosion Inhibition Properties of Mild Steel in Acidic Medium

“…The majority of these compounds have demonstrated mixed-type corrosion inhibition in acidic solutions, protecting mild steel. Benzothiazoles have been employed as corrosion inhibitors for copper and steel in literature reviews [11], although the focus of this paperʹs studies is on the inhibitory properties of cationic surfactant on mild steel in acidic environments. Surface analytical approaches are needed to characterize corrosion inhibitor films to have a comprehensive understanding of the adsorption mechanism for corrosion inhibitors.…”