Study of Zn-Ni and Zn-Co alloy coatings electrodeposited on steel strips I: Alloy electrodeposition and adhesion of coatings to natural rubber compounds

The electrodeposition of Zn-Ni and Zn-Co binary alloy coatings on low carbon steel plates from simple acid baths has been studied. Coatings were examined for their composition, phase structure, morphology and deformability. Their properties and plating conditions were optimized such that these coatings would serve to formulate an improved composite coating systems for steel tire cords, replacing the conventional brass coating. In view of this, adhesion of several as-deposited and deformed coatings to a commercial natural rubber compound was evaluated. A dual-layer coating system consisting of a zinc-rich Zn-Co alloy underlayer and a nickel-rich Ni-Zn alloy top layer was found to exhibit characteristics most suitable for application on steel tire cords.