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Portugaliae Electrochimica Acta

versão impressa ISSN 0872-1904

Port. Electrochim. Acta v.21 n.2 Coimbra  2003

 

Electrochemical Studies of Cu-Al Alloys in Sulphate Solutions with Different pH

 

R.D. Noce, C.S. Fugivara, N. Barelli, A.V. Benedetti*

Instituto de Química da Universidade Estadual Paulista, UNESP. Departamento de Físico-Química, CP. 355, 14801-970 Araraquara, SP, Brasil. E-mail: benedetti@iq.unesp.br

Received 10 September 2002; accepted in revised form 29 January 2003

 

Abstract

The electrochemical behavior of Cu-(0.5-13 wt.%)Al alloys in K2SO4 0.5 mol dm-3 (m = 1.5 M, pH 2-5) was studied using open-circuit potential (Eoc) measurements and polarization curves, in order to know the conditions of copper oxides formation, influence of Al concentration and solution pH on the electrode processes. The open-circuit potential measurements with time indicated that the Eoc decreases with the Al content, due to the lower Al potential compared to Cu. The electrode potentials decrease ca. 20 mV per unity of solution pH as increase pH of the solution. The polarization curves showed changes with the increase of Al concentration. For alloys with up to 3 wt.%Al the obtained Tafel anodic coefficient was 40 mV/decade for low potentials region (E < -320 mV) and 130 mV/decade for the other region (-320 < E/mV < -250), indicating that up to this concentration there is no considerable change in the  electrochemical behavior of the alloys, when compared to pure Cu. For alloys with an Al content from 8 to 13 wt.% the Tafel anodic coefficient was 60 mV/decade. No influence of the solution pH on the Tafel anodic coefficient was observed.

Keywords: Cu-Al alloys, electrochemical oxidation.

 

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Referências

1. K. Mukunthan, L.C. Brown, Metall. Trans. A 19A (1988) 2921-2929.        [ Links ]

2. A. Gulyaev, Physical Metallurgy v.2, MIR Publishers -Moscou (1980) p. 271-286.        [ Links ]

3. B.G. Ateya, E.A. Ashour, S.M. Sayed, J. Electrochem. Soc. 141-1 (1994) 71-78.        [ Links ]

4. R.B. Ross, Metallic Materials Specification Handbook. 3rd ed., London (1968) p.139.        [ Links ]

5. B.A. Kolachev, R.M. Gabidullin, Y.V. Piguzov, Tecnologia de tratamiento térmico de metales y aleciones no férreos, Moscou: Editorial MIR (1983) p.160-202.        [ Links ]

6. R.H. Greaves, H. Wrighton, Practical microscopical metallography. Chapman & Hall, (1983) p. 209-238.        [ Links ]

7. H. Oppenheim, Z. Mettallkd 74-5 (1983) 319-322.        [ Links ]

8. O.K. Harling, G.P. Yu, N.J. Grant, J.E. Meyer, J. Nucl. Mater. 103(1-3) (1981) 127-132.        [ Links ]

9. K. Minamoto, M. Okubo, Electrically conductive copper alloys, Jpn. Kodai Tokkyo Koho JP 6I (1986) p.(86, 146, 223).        [ Links ]

10. V. Petrova, I. Orizarski, A. Draganov, Khim. Ind. (Sofia) 9 (1983) 401-403; Chem. Abstr. 101 (1984) 23016c.        [ Links ]

11. Chiyoda, Chemical Engineering And Construction Co, LTD., Jpn. Kodai Tokkyo Koho JP (CLCO2F1/72) (1982) 82,105,287; Chem. Abstr. 97 (1982) 20295b.        [ Links ]

12. A.B. Fasman, G.L. Padyukova, G.A. Pushkareva, T.V. Kuzora,  Geterog. Katal. Rth, Pt.2, (1983) 139-144; Chem. Abstr. 100 (1984) 216311h.        [ Links ]

13. T.H. Rogers, Marine corrosion, London: George Newnes Pub. Co. (1968) p.124.        [ Links ]

14. P. Collins, D.J. Duquette, Corrosion 34-4 (1978) 119-124.        [ Links ]

15. T.B. Massalski, Binary alloy phase diagrams, 2nd ed., ASM International 1-2 (1992).        [ Links ]

16. J. Kwarciak, Z. Bojarski, H. Morawiec, J. Mat. Sci. 21-3 (1986) 788-792.        [ Links ]

17. J.M. Guilemany, J. Fernandez, R. Franch, A.V. Benedetti, A.T. Adorno, Journal de Physique IV 5: C2 (1995) 361-365.        [ Links ]

18. Y.G. Chun, S.I. Pyun, C.H. Kim, Materials Letters 20(5-6) (1994) 265-270.        [ Links ]

19. S.I. Pyun, Y.G. Chun, British Corrosion Journal 31-2 (1996) 147-152.        [ Links ]

20. B.G. Ateya, E.A. Ashour, S.M. Sayed, Corrosion 50-1 (1994) 20-25.        [ Links ]

21. Z. Han, Y.F. He, H.C. Lin, H. Zhao, J. Matt. Sci. Lett. 19-5 (2000) 393-395.        [ Links ]

22. A.T. Adorno, M.R. Guerreiro, A.V. Benedetti, J. Alloy and Compounds 315(1-2) (2001) 150-157.        [ Links ]

23. L.B. Getsov, A.I. Rybnikov, G.D. Pigrova, Journal de Physique IV 9: P9 (1999) 105-115.        [ Links ]

24. M.R.F. Hurtado, J. Portillo, Y. Maniette, A.T. Adorno, A.V. Benedetti, J. Alloys and Compounds 280 (1998) 188-195.        [ Links ]

25. M.R.F. Hurtado, J.C. Ferrer, A.T. Adorno, P.T.A. Sumodjo, A.V. Benedetti, Electrochemical Society Proceedings, Pennington, NY, PV, 97-26 (1998) 665-676.        [ Links ]

26. U. Bertocci, J. Turner, Encyclopaedia of electrochemistry of the elements. Bard, J.A. (ed.), Reinhold, N.Y., (1974) p. 384-496.        [ Links ]

27. A. Arranz, C. Palacio, Surf. Sci. 355 (1996) 203-213.        [ Links ]

28. C. Deslouis, B. Tribollet, M. Guiliano, M.M. Musiani, J. Appl. Electrochem. 18 (1988) 374-383.        [ Links ]

29. W.H. Smyrl, J. Electrochem. Soc. 132-7 (1985) 1555-1562.        [ Links ]

30. S.S. Rossatto, P.L. Cabot, P.T.A. Sumodjo, A.V. Benedetti, Electrochim. Acta 46 (2001) 1043-1051.        [ Links ]

31. E. Mattsson, J.O’M. Bockris, Trans. Faraday Soc. 55 (1959) 1586-1601.        [ Links ]

32. W. Shen, K. Nobe, Proc. Hackerman Symp. The Electrochem. Soc., Pennington, N.J., 86-7 (1986) 82-90.        [ Links ]

33. S.L.F.A. da Costa, S.M.L. Agostinho, Corrosion 45 (1989) 472-477.        [ Links ]

34. J.S. Newman, Electrochemical System, Prentice-Hall, Englewood Cliffs, NJ (1973).        [ Links ]

35. F.K. Crundwell, Electrochim. Acta 37 (1992) 2707-2714.        [ Links ]

36. S.A. Awad, K.H. Kamel, Z.A. ElHadi, H.A. Bayumi, J. Electroanal. Chem. 199 (1986) 341-350.        [ Links ]

37. P. Sury, H.R. Oswlad, Corrosion Sci. 12 (1972) 77-90.        [ Links ]

 

* Corresponding author. E-mail address: benedeti@iq.unesp.br.

 

Communication presented at XV Ibero-American Meeting of Electrochemistry.

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