Estudo da liga Ni-Co-Fe na presença do complexante citrato de sódio.

Abstract

A ternary alloy Ni-Co-Fe was electrodeposited and operational and bath composition parameters in relation to its corrosion resistance were optimized. The development of stable baths with relatively high pH levels and the use of complexing agent to stabilize it is crucial for getting good quality films and for increasing the lifetime of the electrolytic bath. The effect of current density and mechanical agitation to obtain Ni-Co-Fe in the presence of a complexing agent and at a controlled high pH has been studied in this work. The response surface methodology was used as optimization tool. The baths used to obtain these alloys without complexing agents were unstable. Good quality films of Ni-Co-Fe alloys were obtained by using an electrochemical bath with the complexing agent. The coatings obtained had good adhesion and gloss. The excelent operating conditions for obtaining this film were current density of 30 mA / cm2 and pH 8.5. It was observed the presence of micro-nodules on the surface of the alloys studied, the chemical composition of the coating was better Ni739Coio,2Fei5;9 and also showed a crystalline behavior and a cathodic efficiency of 85%.