Electrodeposited Ni/zinc myristate composite coating with long-time corrosion resistance

Abstract

This study employed the electrodeposition technique to fabricate a composite coating of Ni/zinc myristate (ZnMA) on the copper plate. Two distinct electrodeposition processes were conducted to form a micro/nano-porous nickel layer. Subsequently, a zinc-based outer layer was deposited at −4 V for 10 min, resulting in superhydrophobicity with a water contact angle of approximately 157°. The ZnMA outer layer nucleated at the defects and filled the pores of the nickel layer, which reduced imperfections in the coating and enhanced its corrosion resistance. The corrosion current density of the prepared coating was approximately 1.74 × 10⁻⁹ A·cm⁻² in the 3.5 wt-% NaCl solution, which was four orders of magnitude lower than that of the substrate. After a 30-day immersion in a 3.5 wt-% NaCl solution, the impedance modulus of the coating decreased from 3.29 × 10⁷ Ω·cm² to 2.78 × 10⁵ Ω·cm², remaining two orders of magnitude higher than that of the copper substrate. The structure and composition of the coating after immersion demonstrated no significant changes and maintained its hydrophobic properties. These findings confirm that the prepared coating exhibits remarkable durability in anti-corrosion performance, rendering it a promising candidate for protective applications in corrosive environments.