Explicit microstructural evolution and electrochemical performance of zinc-eggshell particles composite coating on mild steel

Zinc coatings are increasingly deployed for use in engineering, technology and industries. Electrodeposition using only Zinc metal cannot be guaranteed under some aggressive environment. Development of surface coating of mild steel with CaCO₃ coating have received attention in recent time to overcome the limitation of Zn-coating, however the cost of the coating developed from CaCO₃ is usually high since is the major materials used in the production of cement. As a resulted of these effort are been made to develop coating that will be less cost, ecofriendly and corrosion resistance. In this work Co-deposition of Zn-eggshell powder (ESp) composite coating on mild steel was reported with the view to combat this problem. The ESp was varies from 0 to 20 g/l during the electrodeposition. The coating thickness, surface roughness, microstructure, thermal analysis, electrical conductivity and Tafel polarization in sub-sea water were determined. The addition of ESp changes the morphological and texture of the coating. The thermal properties and corrosion rate were enhances. Maximium corrosion protection efficiency of 99.92% was obtained at Zn-20 g/lESp. It was established that eggshell can be used to improved corrosion resistance and thermal stability of Zinc coating of mild steel.