Planning and processing of Zn-Ni alloy thin film by electrodeposition

Abstract

This work aims to improve and characterize a Zn-Ni alloy thin film from a sulfated bath by an electrochemical process. Experimental planning was applied using Minitab 19. For the selection of the best bath composition, a mixture design was applied. It was found that the best bath composition is [boric acid] = 0.1M, [saccharin] = 0.3 g/L, and [2-butene-1,4-diol] = 0.1 g/L. In order to optimize the best experimental conditions to have a better coating an application of the Box-Behnken design has been examined. Temperature, current density, and the ratio [Ni2+]/[Zn2+] are the various parameters. It was found that the best coating in terms of quality, corrosion resistance, brightness, and hardness was obtained under the following conditions: T= 30°C; i= 0.5A/dm2 and [Ni2+]/[Zn2+] = 0.53 with a theoretical response of 312.66 HV and an experimental response of 312.30 HV.These results were confirmed by morphological (SEM) and elemental (EDS) analyses.