Evaluation of the shielding effectiveness of electrodeposited Zn–Ni, Zn–Co, Ni–Co, and Zn–Ni–Co alloy coatings

Abstract

This paper investigates the effect of different alloy coatings (Zinc–Nickel (Zn–Ni), Zinc–Cobalt (Zn–Co), Nickel–Cobalt (Ni–Co), and Zinc–Nickel–Cobalt (Zn–Ni–Co)) on surface properties and electromagnetic interference (EMI) shielding effectiveness. These alloy coatings are electroplated on the surface of copper material in a sulfate bath using a power supply. The coating composition, morphology, and phase structures of the alloy coatings are examined by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD); absorption and electromagnetic shielding values in the X-band frequency range are investigated by Vector Network Analyzer (VNA) using coaxial holder method. According to the results of the surface morphology of the alloy coatings, the expected surface structures are generally formed. XRD results also reveal phases that differ according to alloy type. As a result of this study, it is determined that the best electromagnetic shielding efficiency is found in Zn–Ni–Co alloy coating whereas Ni–Co alloy coating has the best absorbance value. Based on these results, such binary and ternary metal alloy coatings can be considered as a decent alternative to increase shielding efficiency for materials such as copper, which already have good conductivity and a certain level of shielding.