Heterostructured melamine resin Spheres@GO reinforced epoxy composite achieving robust Corrosion-Resistance of Zn-Al-Mg coated steel for automotive applications

[Display omitted] •Hierarchical melamine resin spheres (MRS) were synthesized using PVA assisted polymerization approach.•Graphene oxide (GO) was decorated using MRS to develop heterostructured MRS@GO nanohybrid via solution mixing.•As-developed MRS@GO was reinforced as nanofiller in epoxy (EP) coating for enhanced durability of the coating and superior ZAM steel protection.•Synergistic intercomponent mechanism supported the long-term protection of ZAM-steel against over film and under film corrosion in aggressive environment. Dual threats of over-film (degradation) and under-film filiform corrosion (FFC) pose a significant challenge to the reliable application of Zn-Al-Mg coated steel (ZAM-steel), necessitating the development of effective protection strategies. This study introduces a novel MRS@GO nanohybrid, integrated within epoxy (EP) coatings, to enhance the corrosion resistance of ZAM-steel in 3.5 wt% NaCl solution. The hierarchical structure of MRS@GO synergistically combines the barrier properties of an insulating material (MRS) with the electrochemical benefits of a conducting material (GO), providing superior protection. This dual functionality significantly improves the overall performance and durability of ZAM-steel, making it a promising candidate as the decorative coating for the automotive industry.