Electrodeposited Zn–Ni alloy nanocoatings: structure, performance, and sustainable applications

Alloy coatings have completely transformed the performance of steel components, offering essential protection against corrosion and mechanical wear. Therefore, the necessity to engineer sustainable chemical coatings like that of Zn-Ni alloys was motivated because of their ability to outperform other potentially toxic metal alloy coatings. These coatings are known for their superior tribological corrosion resistance and lower susceptibility to hydrogen embrittlement. Zn–Ni coatings containing 10–15 wt% Ni have been widely reported to exhibit the γ-phase, resulting in higher hardness (≈ 180–450 VHN) compared to pure Zn and a notable reduction in corrosion rate. This review provides insights into the advanced electrodeposition methods, which enhance the properties of the Zn-Ni alloys leading them to showcase superior polarization resistance and reduced mass loss from wear-induced corrosion. These deposition methods boost corrosion resistance and reduce coating thickness for metal alloys. Bolts, threaded parts, brake systems and fuel components are some examples of high-temperature settings and applications exposed to ultraviolet light, hydraulic fluids, and fuels in which these coatings can be of particular benefit. The report also highlights the hierarchical arrangement, composition, and performance characteristics of Zn-Ni alloy coatings for optimizing their application in various industrial contexts. This analysis thus underscores the potential of Zn-Ni coatings as durable and eco-friendly, which further ensures the longevity of steel components in challenging environments. Therefore, it is inferred from this comprehensive review that the readers will procure an adequate understanding of the pivotal role of Zn-Ni alloy coatings in advancing corrosion protection and mechanical integrity, thus reaffirming their status as indispensable solutions for modern industrial challenges.