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Electrochemical Study of the Passivation and Passive Film Breakdown of Mg70 Zn30 Metallic Glass

Published online by Cambridge University Press:  26 February 2011

Patrick L. Hagans*
Affiliation:
The Dow Chemical Co., Central Research, 1776 Bldg., Midland, MI 48674
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Abstract

Anodic dc polarization measurements of glassy Mg70 Zn30 in pH=9.3 boric-borate electrolyte with and without the presence of Cl were used to study both passive film formation and breakdown. In the absence of C a single, broad passivation peak is observed which is very similar to that found with triply distilled Mg except that the large increase in peak potential and reduction in peak current density indicates that a more stable film has formed on Mg70 Zn30. Also observed with Mg70 Zn30 but not with Mg, Zn or other different types of crystalline Mg alloys is a large, narrow peak in the transpassive region (i.e., the region where the passive film begins to break down and/or O2 evolution commences). This process of breakdown of the passive film and further oxidation of the base metal is totally irreversible and is almost completely missing on the second and subsequent voltage sweeps. Although speculative in nature, existing evidence suggests that a phase transition has occurred within the passive film itself. In the presence of Cl this process does not occur as passive film breakdown is initiated via a pitting mechanism at a potential nearly 2.5 Volts more negative than the onset of O2 evolution. Nevertheless, the onset of pitting is still 0.4 Volts more positive than that found for Mg indicating again that a much more protective film has formed on Mg70 Zn30

Type
Articles
Copyright
Copyright © Materials Research Society 1987

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References

1. Hashimoto, K., in Amorphous Metallic Alloys, edited by Luborsky, F. E. (Butterworths, London, 1983), pp. 471–86.CrossRefGoogle Scholar
2. Hashimoto, Koji and Masumoto, Tsuyoski, in Glassy Metals, Magnetic, Chemical and Structural Properties, edited by Hasegawa, Ryusuke (CRC Press, Boca Raton, Florida, 1983), pp. 235–62.; Treatise on Materials Science and Technology, 20 (Academic Press, NY, 1981), pp. 291–324.Google Scholar
3. Diegle, R. B., Sorensen, N. R., Tsuru, T. and Latanision, R. M., in Treatise on Materials Science and Technology,23 (Academic Press, NY, 1983), pp. 59102.Google Scholar
4. Waseda, Y. and Aust, K. T., J. Mater. Sci., 16, 2337 (1981).CrossRefGoogle Scholar
5. Diegle, R. B., J. Non.-Cryst. Solids, 61&62, 601 (1984).CrossRefGoogle Scholar
6. Boswell, P. G., Mater. Sci. and Engr., 34, 1 (1978).CrossRefGoogle Scholar
7. Calka, A., Madhara, M., Polk, D. E., Giessen, B. C., Matyja, H. and Sande, J. Vander, Ser. Metall., 11, 65 (1977).CrossRefGoogle Scholar
8. von Heimendahl, L., J. Phys F: Metal Phys., 9, 161 (1979).CrossRefGoogle Scholar
9. Nassif, E., Lamparter, P., Sperl, W. and Steeb, S., Naturforsch, Z. A: Phys., Phys. Chem. Kosmophys, 38A, 142 (1983).Google Scholar
10. Suck, J-B., Rudin, H., Guntherodt, H-J. and Beck, H., J. Phys. C: Solid State Phys., 14, 2305 (1981).CrossRefGoogle Scholar
11. Hafner, J. and Heimendahl, L.von, Phys. Rev. Lett., 42, 386 (1979).CrossRefGoogle Scholar
12. Hagans, Patrick L., in Proc. of 41st World Magnesium Conference (International Magnesium Assoc., Dayton, OH, 1984), pp. 30–8.Google Scholar
13. Akavipat, S., Hale, E. B., Habermann, C. E. and Hagans, P. L., Mater. Sci. and Engr., 69, 311 (1985); in Proc. Int. Symp. On Fundamental Aspects of Corrosion Protection by Surface Modification, edited by E. McCafferty, C. R. Clayton and J. Oudar, (The Electrochemical Soc., Pennington, NJ, 1984), pp. 52–61.CrossRefGoogle Scholar
14. Hagans, P., Langhoff, C., Moll, D., Perettie, D. and Yates, R., in Proc. of SPIE, V.459, Laser Assisted Deposition, Etching and doping (Society of Photo-Optical Instrumentation Engineers,Google Scholar
15. Hagans, P. L. and Yates, R. L., U.S. Patent 4,613,386 (1986).Google Scholar
16. Bakhru, Prakash U., Bow, Kenneth E., Hagans, Patrick L. and Lewis Shadoff, in Proc. of 34th International Wire and Cable Symp., (U.S. Army Communications-Electronics Command, Fort Monmouth, NJ, 1985), pp.6175.Google Scholar
17. Ogura, Kotaro and Sato, Kazusi, in Passivity of Metals, edited by Robert Frankenthal, P. and Kruger, Jerome (The Electrochemical Soc., Pennington, NJ, 1978), p. 469.Google Scholar
18. Hagans, Patrick L., presented at The Electrochemical Society Spring Mtg., San Fran., CA, 1983. (See Extended Abstracts, V.83-I, The Electrochem. Soc., Pennington, NJ, 1983, pp.112–3.Google Scholar
19. Landolt, D., in Passivity of Metals, edited by Frankenthal, Robert P. and Kruger, Jerome (The Electrochem. Soc., Pennington, NJ, 1978) pp. 484503; James P.Hoare, in Passivity of Metals, edited by Robert P. Frankenthal and Jerome Kruger (The Electrochem. Soc., Pennington, NJ, 1978) pp.505–20.Google Scholar
20. Loose, W. S. in Corrosion Handbook, edited by Uhlig, H. H. (Wiley, NY, 1948), pp. 218–52.Google Scholar
21. Whitty, L., LaQue, F. L. and Copson, H. R. (editors), in Cor- Resistance of Metals and Alloys (Reinhold, NY, 1963), Chap. 7.Google Scholar
22. Straumanis, M. E. and Bhatia, B. K., J. Electrochem. Soc., 110, 1113 (1963).CrossRefGoogle Scholar
23. Pangarov, N., Electrochimica Acta, 28, 763 (1983).CrossRefGoogle Scholar
24. Hagans, P. L., unpublished results.Google Scholar