Perspectives in corrosion-performance of Ni–Cu coatings by adding Y 2 O 3 nanoparticles

Abstract

Ni–Cu alloy coatings are well-known for their favourable corrosion resistance. However, further improvement in their corrosion resistance through incorporation of reinforcing agents can open new windows of industrial applications. The main focus of this paper is on evaluating the effects of Y₂O₃ nanoparticles inclusion on the corrosion performance of electrodeposited Ni–Cu alloy coatings. Electrochemical impedance spectroscopy (EIS), Tafel polarization, and open circuit potential (OCP) measurements were used to assess the corrosion performance of the coatings. According to the results, there is no obvious change in the phase structure of the coatings. Moreover, the surface morphology of Ni–Cu alloy coatings change from cauliflower-like to featureless with introduction of Y₂O₃ nanoparticles. Mapping analysis confirms the uniform dispersion of the embedded nanoparticles throughout the matrix. Ni–Cu–4 g L⁻¹ Y₂O₃ nanocomposite coating exhibits the most favourable corrosion performance mainly due to possessing the highest Y₂O₃ content along with minimum microstructural defects including pores, voids and micro-cracks.