Electrogalvanization using new generation coatings with carbonaceous additives: progress and challenges

Abstract Zinc is an important coating material for corrosion protection of carbon steel because of its sacrificial behavior. Continuous efforts have therefore been made over the years to perform required microstructural engineering to further enhance the corrosion resistance behavior of Zn based coatings. This review is focused on a new class of recently developed coatings in which carbonaceous materials like graphene, graphene oxide and carbon nanotubes (CNTs) are incorporated into Zn metal matrix to significantly affects its electrochemical response. Impermeability of the graphene and graphene oxide and hydrophobicity of the CNTs are the principal reasons behind the adoption of these carbonaceous additives. Over the years, the researchers have, however, observed that the in addition to the above, noticeable microstructural and morphological alterations introduced in the coating matrix due to these carbonaceous additives also contribute significantly to the corrosion resistance behavior. An understanding of the microstructural evolution of the coatings as a function of the additive volume fraction is therefore required to design robust composite coatings with enhanced corrosion resistance performance.