Effect of iron as alloying element on electrochemical behaviour of 90 : 10 Cu–Ni alloy A. M. Taher, G. Jarjoura and G. J. Kipouros* Copper–nickel alloys have been used in many applications in marine environments, because of their excellent corrosion and biofouling resistance. In this study, the effects of iron as an alloying element on the corrosion behaviour of copper–10 wt-% nickel alloy in artificial saline solutions and natural sea water were investigated. Synthetic copper–nickel alloys were prepared in an induction furnace under an argon–7 vol.-% hydrogen atmosphere in cylindrical boron nitride crucibles. They were then homogenised at 950uC for 10 h under the same protective atmosphere. Linear sweep polarisation, cyclic polarisation, Tafel extrapolation and cyclic voltammetry techniques were performed in this investigation. Following the electrochemical measurements, the corrosion products and the passive film were analysed using a field emission scanning electron microscope (FE-SEM), electron probe microanalysis, energy dispersive spectrometry (EDS), wavelength dispersive spectrometry (WDS) and X-ray diffraction (XRD). The electrochemical behaviour of the synthetic Cu–Ni–Fe alloys depends on maintaining iron in a single phase in the solid solution (the maximum amount of iron that can be used was 1?5 wt-%). Quenching improves the electrochemical behaviour of synthetic Cu–Ni–Fe alloys containing relatively high iron content. The outer layer of the passive film is porous in the absence of iron, but when iron is added, the pores disappear and cracks appear. When no sulphate is present in the solution, the passive film formed on synthetic Cu–Ni–Fe alloys consists entirely of chlorides, and Fe 2 O 3 . In the presence of sulphate, FeS and NiS were detected in the corrosion film. On a utilise ´ les alliages de cuivre–nickel a ` de nombreuses fins en milieux marins, gra ˆce a ` leur excellente re ´ sistance a ` la corrosion et a ` l’incrustation biologique. Dans cette e ´ tude, on a examine ´ l’effet du fer en tant qu’e ´le ´ ment d’alliage sur le comportement de corrosion d’un alliage de cuivre– 10% en poids de nickel dans des solutions salines artificielles et dans de l’eau de mer naturelle. On a pre ´ pare ´ des alliages synthe ´ tiques de cuivre–nickel dans un four a ` induction dans une atmosphe ` re d’argon–7% en volume d’hydroge ` ne dans des creusets cylindriques de nitrure de bore. On les a ensuite homoge ´ne ´ ise ´s a ` 950uC pendant 10 heures sous la me ˆ me atmosphe `re protectrice. Dans cette investigation, on a utilise ´ des techniques de polarisation line ´aire a ` balayage, de polarisation cyclique, d’extrapolation de Tafel et de voltampe ´ rome ´ trie cyclique. Apre `s les mesures e ´ lectrochimiques, on a analyse ´ les produits de corrosion et le film passif en utilisant un microscope a ` balayage e ´ lectronique a ` champs par e ´ mission d’ions (FE-SEM), la microanalyse par e ´ lectrons, la spectrome ´trie des rayons X a ` dispersion d’e ´ nergie (EDS), la spectrome ´ trie dispersive en longueur d’onde (WDS) et la diffraction des rayons X (XRD). Le Materials Engineering Programme, Dalhousie University, Halifax, NS B3H 4R2, Canada *Corresponding author, email georges.kipouros@dal.ca ß 2011 Canadian Institute of Mining, Metallurgy and Petroleum Published by Maney on behalf of the Institute Received July 6 2010; accepted August 16 2011 DOI 10.1179/000844311X13117643274758 Canadian Metallurgical Quarterly 2011 VOL 50 NO 4 425