Electrochemical studies of copper, copper-aluminium and copper-aluminium-silver alloys: Impedance results in 0.5M NaCl

Abstract The electrochemical behaviour of Cu, Cu-Al and Cu-Al-Ag alloys in aqueous solutions of NaCl (0.5 M, pH = 3.00) was studied by means of voltammetric methods and electrochemical impedance spectroscopy. The surfaces were examined by SEM and EDX analysis. Cu-Al-Ag alloy shows a potentiodynamic behaviour similar to that of the pure copper electrode while the Cu-Al alloy presents some minor differences. In the active dissolution region the electrodes suffer pitting corrosion and in the other potential regions there are the formation of a passivant film with composition depending on the potential. The impedance responses of the electrodes are discussed. An electrodissolution mechanism is proposed and the effect of the alloying elements upon the impedance response and polarisation curves is explained. The main effects are due to the production of copper and silver chlorides and aluminium oxides/ hydroxides at the corroding interface. The addition of Al or (Al + Ag) increases the corrosion resistance of pure copper.

[1]  Digital Impedance for Faradaic Analysis III. Copper Corrosion in Oxygenated 0.1N HCl , 1985 .

[2]  G. Rao,et al.  Mono- and multilayer formation studies of silver iodide on silver electrode from iodide-containing solutions , 1987 .

[3]  R. Brossard.  Dissolution of Copper Chloride in Concentrated LiCl Solution , 1983 .

[4]  J. Newman,et al.  Singular Perturbation Analysis of the Faradaic Impedance of Copper Dissolution Accounting for the Effects of Finite Rates of a Homogeneous Reaction , 1989 .

[5]  Z. Tanabe.  Effect of metal composition and heat treatment on de-aluminification of CuAl alloys , 1964 .

[6]  M. Musiani,et al.  Electrochemical behaviour of copper in neutral aerated chloride solution. I. Steady-state investigation , 1988 .

[7]  J. Garrido,et al.  Potentiodynamic behaviour of CuA1Ag alloys in NaOH: a comparative study related to the pure metals electrochemistry , 1991 .

[8]  G. Horányi,et al.  Radiotracer study of adsorption phenomena on copper electrodes. Study of the adsorption of chloride ions and thiourea on "copperized" electrodes , 1983 .

[9]  W. Smyrl.  Digital Impedance for Faradaic Analysis II . Electrodissolution of Cu in , 1985 .

[10]  P. Sumodjo,et al.  Electrochemical behaviour of copper electrode in concentrated sulfuric acid solutions , 1993 .

[11]  J. C. Griess,et al.  The Anodic Dissolution of Copper in Flowing Sodium Chloride Solutions Between 25° and 175°C , 1973 .

[12]  J. Bessone,et al.  An EIS study of aluminium barrier-type oxide films formed in different media , 1992 .

[13]  I. R. Hill,et al.  A comparative study of the efficiency of some organic inhibitors for the corrosion of copper in aqueous chloride media using electrochemical and surface enhanced Raman scattering techniques , 1985 .

[14]  A. Arvia,et al.  Electrochemical behaviour of copper in aqueous solution containing potassium ethylxanthate , 1987 .

[15]  P. Sumodjo,et al.  Electrochemical Studies with Copper-Based Alloys Open-Circuit Potential Oscillations in Alkaline Media , 1993 .

[16]  F. Crundwell.  A model for the ac-impedance of an electrode coated by a precipitated salt film , 1991 .

[17]  C. K. Smith,et al.  The anodic behavior of silver in chloride solutions—I. The formation and reduction of thin silver chloride films , 1987 .

[18]  I. Villegas,et al.  The surface chemistry of Cu (100) in HCl solutions as a function of potential: a study by LEED, Auger spectroscopy and depth profiling , 1990 .

[19]  A. Arvia,et al.  The influence of halide ions at submonolayer levels on the formation of oxide layer and electrodissolution of copper in neutral solutions , 1988 .

[20]  J. Newman,et al.  Impedance Model for a Concentrated Solution Application to the Electrodissolution of Copper in Chloride Solutions , 1984 .

[21]  H. Shih,et al.  Fluoride-Activated Deterioration Mechanism of the Oxide Film on Alpha Aluminum Bronze , 1989 .

[22]  H. Oswald,et al.  On the corrosion behaviour of individual phases present in aluminium bronzes , 1972 .

[23]  J. Crousier,et al.  Voltammetry study of copper in chloride solution , 1988 .

[24]  J. Garrido,et al.  The influence of the electrochemical treatment on Cu-Al-Ag alloys in deaerated 0.5 M NaOH , 1991 .

[25]  S. Miura,et al.  Intergranular corrosion of copper and α-Cu-Al alloy bicrystals , 1991 .

[26]  Ravindra Singh,et al.  Influence of Minor Additions of La, Ce, and Nd on the Mechanical and Corrosion Behavior of Aluminum Bronze in HNO3 Solution , 1989 .

[27]  T. Furtak,et al.  Aspects of the adsorption of chloride on silver revealed through surface enhanced Raman scattering , 1987 .

[28]  Pyun Su-Il,et al.  Effect of aluminium content on the anodic behaviour of copper-aluminium alloys in 3.5 wt% NaCl solution , 1994 .

[29]  J. C. Fister,et al.  The Mechanism of Dealloying of Copper Solid Solutions and Intermetallic Phases , 1984 .

[30]  D. Thierry,et al.  Simultaneous Raman Spectroscopy and Electrochemical Studies of Corrosion Inhibiting Molecules on Copper , 1985 .

[31]  O. R. Mattos,et al.  Mass‐Transport Study for the Electrodissolution of Copper in 1M Hydrochloric Acid Solution by Impedance , 1993 .

[32]  A. Pearlstein,et al.  Film Formation and Current Oscillations in the Electrodissolution of Cu in Acidic Chloride Media I . Experimental Studies , 1985 .

[33]  J. Newman,et al.  The Effect of Schmidt Number on the Faradaic Impedance of the Dissolution of a Copper Rotating Disk , 1988 .

[34]  M. Musiani,et al.  Electrochemical behaviour of copper in neutral aerated chloride solution. II. Impedance investigation , 1988 .

[35]  A. Arvia,et al.  Kinetics and Mechanism of Silver Chloride Electroformation during the Localized Electrodissolution of Silver in Solutions Containing Sodium Chloride , 1986 .