Development of nano-structured Zn-Ni multilayers and their corrosion behaviors

Abstract

Composition modulated multilayer alloy (CMMA) coatings of Zn-Ni was developed using single bath technique (SBT). CMMA coatings were developed galvanostatically using square current pulses. The cyclic cathode current densities (CCCDs) and number of layers were optimized for highest corrosion resistance. Experimental results showed that CMMA coating, developed at 2.0/5.0 A/dm2, having 300 layers is ?29 times higher corrosion resistant than monolithic alloy of same thickness. Tafel and impedance data revealed its good protection ability. The improved corrosion behavior exhibited by multilayers was explained using dielectric spectroscopy. The formation of multilayer and corrosion mechanism was analyzed using scanning electron microscopy (SEM). Copyright Taylor & Francis Group, LLC.