Journal of Coatings Technology

, Volume 74, Issue 927, pp 53–61 | Cite as

Electrochemical and salt spray analysis of multilayer ormosil/conversion coating systems for the corrosion resistance of 2024-T3 aluminum alloys

  • Tammy L. Metroke
  • Olga Kachurina
  • Edward T. Knobbe
Technical Articles

Abstract

The corrosion resistance characteristics of multilayer coating systems comprised of a conversion coating base layer and an organically modified silicate (ormosil) topcoat have been analyzed using salt spray and potentiodynamic polarization curve analyses. The effectiveness of the multilayer coating systems was found to depend on the presence of an electrochemically active species in the conversion coating and on the presence of a curing agent in the ormosil system. Multilayer coatings systems comprised of conversion coatings that contain active corrosion inhibitors were found to provide high degrees of corrosion protection. In all cases, the presence of the ormosil was found to enhance the corrosion resistance of the underlying conversion coating. The use of multilayer ormosil/conversion coating systems enhances the corrosion protection of 2024-T3 aluminum alloy by combining previously developed corrosion protection methods with emerging sol-gel technology.

Keywords

Aluminum Alloy Corrosion Protection Hexavalent Chromium Salt Spray Conversion Coating 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in to check access.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. (1).
    Sax, N.J.,Dangerous Properties of Industrial Materials, Fifth Ed., Van, New York, 1993.Google Scholar
  2. (2) (a).
    Nylund, A., “Chromium-Free Conversion Coatings for Aluminum Surfaces,”Aluminum Transactions, 2, 121 (2000);Google Scholar
  3. (2) (b).
    Smith, C.J.E., Baldwin, K.R., Garrett, S.A., Gibson, M.C., Hewins, M.A.H., and Lane, P.L., “The Development of Chromate-Free Treatments for the Protection of Aerospace Aluminum Alloys,”ATB Metallurgie, 37, 266 (1997);Google Scholar
  4. (2) (c).
    Puippe, J., “Surface Treatments of Aluminum for Space Applications,”Galvanotechnik., 90, 3003 (1990);Google Scholar
  5. (2) (d).
    Twite, R.L. and Bierwagen, G.P., “Review of Alternatives to Chromate for Corrosion Protection of Aluminum Aerospace Alloys,”Prog. Org. Coat., 33, 91 (1998).CrossRefGoogle Scholar
  6. (3).
    Roland, W. and Kresse, J., “New Chromium-Free Processes for the Chemical Pretreatment of Aluminum Surfaces,”ATB Metallurgie, 37, 89 (1997).Google Scholar
  7. (4) (a).
    Hinton, B.R.W., “Corrosion Inhibition with Rare Earth Metal Salts,”J. Alloys Compd., 180, 15 (1992);CrossRefGoogle Scholar
  8. (4) (b).
    Arnott, D.R., Ryan, N.E., Hinton, B.R.W., Sexton, B.A., and Hughes, A.E., “XPS Studies of Cerium Corrosion Inhibition on 7075 Aluminum Alloy,”Appl. Surf. Sci., 22, 236 (1985);CrossRefADSGoogle Scholar
  9. (4) (c).
    Morris, E., Stoffer, J.O., O’Keefe, T.J., Yu, P., and Lin, X., “Evaluation of Non-Chrome Inhibitors for Corrosion Protection of High-Strength Aluminum Alloys,”Polymeric Materials, 81, 167 (1999);Google Scholar
  10. (4) (d).
    Ramanathan, L.V., “Corrosion Control with Rare Earths,”Corrosion Prevention & Control, 4, 87 (1998).Google Scholar
  11. (5).
    Schriever, M.P., U.S. Patent 5,551,994 (Sept. 3, 1996).Google Scholar
  12. (6) (a).
    Danilidis, I., Sykes, J.M., Hunter, J.A., and Scamans, G.M., “Manganese Based Conversion Treatment,”Surface Engineering, 15, 401 (1999);CrossRefGoogle Scholar
  13. (6) (b).
    Srinivasan, P.B., Sathiyanarayanan, S., Marikkannu, C., Balakrishnan, K., “A Non-Chromate Chemical Conversion Coating for Aluminum Alloys,”Corrosion Prevention & Control, April, 35 (1995).Google Scholar
  14. (7).
    Rangel, C.M., Simões, A., and Newman, R.C., “The Formation of an Alternative Conversion Coating for Aluminum in Buffered Molybdate Solutions,”Portugaliæ Electrochimica Acta, 15, 383 (1997).Google Scholar
  15. (8).
    Schram, T., Goeminne, G., Terryn, H., Vanhoolst, W., and Van Espen, P., “Study of the Composition of Zirconium Based Chromium Free Conversion Layers on Aluminum,”Trans. I.M.F., 73, 91 (1995).Google Scholar
  16. (9) (a).
    van Ooij, W.J., Zhang, C., Zhang, J.W., and Yuan, W., “Pretreatment for Painting by Organofunctional and Non Functional Silanes,”Electrochemical Society Proceedings, 97-41, 222 (1998);Google Scholar
  17. (9) (b).
    van Ooij, W.J., Song, J., and Subramanian, V., “Silane-Based Pretreatments of Aluminum and Its Alloys as Chromate Alternatives,”ATB Metallurgie, 37, 137 (1997);Google Scholar
  18. (9) (c).
    Child, T.F. and van Ooij, W.J., “Application of Silane Technology to Prevent Corrosion of Metals and Improve Paint Adhesion,”Trans. IMF., 77, 64 (1999);Google Scholar
  19. (9) (d).
    Subramanian, V. and van Ooij, W.J., “Silane Based Metal Pretreatments as Alternatives to Chromating,”Surface Engineering, 15, 168 (1999);CrossRefGoogle Scholar
  20. (9) (e).
    van Ooij, W.J. and Child, T., “Protecting Metals with Silane Coupling Agents,”ChemTech, 28, 26 (1998);Google Scholar
  21. (9) (f).
    Hinton, B.R., “Corrosion Prevention and Chromates: The End of an Era?”Metal Finishing, 89, 15 (1991).Google Scholar
  22. (10).
    Delaunois, F., Poulain, V., and Petitjean, J.P., “A Pretreatment Against Localized and Filiform Corrosion Applied to Aluminum Alloys: the Trivalent Chromium Pretreatment,”ATB Metallurgie, 37, 106 (1997).Google Scholar
  23. (11) (a).
    Ilevbare, G.O., Scully, J.R., Yuan, Y., and Kelly, R.G., “Inhibition of Pitting Corrosion on Aluminum Alloy 2024-T3: Effect of Soluble Chromate Additions vs. Chromate Conversion Coating,”Corrosion, 56, 227 (2000);CrossRefGoogle Scholar
  24. (11) (b).
    Hughes, A.E., Taylor, R.J., and Hinton, B.R.W., “Chromate Conversion Coatings on 2024 Al Alloy,”Surface and Interface Analysis, 25, 223 (1997);CrossRefGoogle Scholar
  25. (11) (c).
    Lytle, F.W., Greegor, R.B., Bibbins, G.L., Blohowiak, K.Y., Smith, R.E., and Tuss, G.D., “An Investigation of the Structure and Chemistry of Chromium Conversion Surface Layer on Aluminum,”Corrosion Science, 37, 349 (1995);CrossRefGoogle Scholar
  26. (11) (d).
    Jeffcoate, S., Isaacs, H.S., Aldykiewicz, A.J., and Ryan, M.P., “Chromate in Conversion Coatings: a XANES Study of its Concentration and Mobility,”J. Electrochem. Soc. 147, 540 (2000);CrossRefGoogle Scholar
  27. (11) (e).
    Xia, L., McCreery, R.L., “Chemistry of Chromate Conversion Coating of Aluminum Alloy AA2024-T3 Probed by Vibrational Spectroscopy,”J. Electrochem. Soc. 15, 3083 (1998).CrossRefGoogle Scholar
  28. (12).
    Waldrop, J.R. and Kendig, M.W., “Nucleation of Chromate Conversion Coatings on Aluminum 2024-T3 Investigated by Atomic Force Microscopy,”Electrochemical Society Proceedings, 97-26, 557 (1998).Google Scholar
  29. (13).
    Laget, V., Jeffcoate, C., Isaacs, H.S., and Buchheit, R.G.,Electrochemical Society Proceedings, 99-26, 173 (2000).Google Scholar
  30. (14).
    Schriever, M.P., U.S. Patent 5,873,953 (Feb. 2, 1999).Google Scholar
  31. (15).
    Pearlstein, F. and Agarwala, V.S., U.S. Patent 5,304,257 (Apr. 19, 1994).Google Scholar
  32. (16).
    Pearlstein, F. and Agarwala, V.S., “Trivalent Chromium Solutions for Applying Chemical Conversion Coatings to Aluminum Alloys or for Sealing Anodized Aluminum,”Plating and Surface Finishing, 81, 50 (1994).Google Scholar
  33. (17) (a).
    Schmidt, H.K., “Aspects of Chemistry and Chemical Processing of Organically Modified Ceramics,”Mater. Res. Soc. Symp. Proc., 180, 961 (1990);Google Scholar
  34. (17) (b).
    Mackenzie, J.D., “Structures and Properties of Ormosils,”J. Sol-Gel Sci. Technol., 2, 81 (1994);CrossRefGoogle Scholar
  35. (17) (c).
    Schubert, U., Hüsing, N., and Lorenz, A., “Hybrid Inorganic-Organic Materials by Sol-Gel Processing of Organofunctional Metal Alkoxide,”Chem. Mater., 7, 2010 (1995);CrossRefGoogle Scholar
  36. (17) (d).
    Sanchez, C. and Ribot, F., “Design of Hybrid Organic-Inorganic Materials Synthesized Via Sol-Gel Chemistry,”New J. Chem., 18, 1007 (1994);Google Scholar
  37. (17) (e).
    Livage, L., “The Sol-Gel Route to Advanced Materials,”Mater. Sci. Forum, 152–153, 43 (1994).CrossRefGoogle Scholar
  38. (18) (a).
    Guglielmi, M., “Sol-Gel Coatings on Metals,”J. Sol-Gel Sci. Tech., 8, 443 (1997);Google Scholar
  39. (18) (b).
    Metroke, T.L., Parkhill, R.L., and Knobbe, E.T., “Passivation of Metal Alloys using Sol-Gel-Derived Materials—A Review,”Prog. Org. Coat., 41, 233 (2001).CrossRefGoogle Scholar
  40. (19) (a).
    Kato, K., “Preparation of SiO2 Films from Si(OC2H5)4-C2H5OH-H2O Solutions Without Catalysts,”J. Mater. Sci., 28, 1445 (1992);CrossRefADSGoogle Scholar
  41. (19) (b).
    Kato, K., “Enhancement of the Corrosion Resistance of Substrates by Thin SiO2 Coatings Prepared from Alkoxide Solutions Without Catalysts,”J. Mater. Sci., 28, 4033 (1993).CrossRefADSGoogle Scholar
  42. (20).
    Kasemann, R. and Schmidt, H., “Coatings for Mechanical and Chemical Protection Based on Organic-Inorganic Sol-Gel Nanocomposites,”New J. Chem., 18, 1117 (1994).Google Scholar
  43. (21).
    Donley, M.S., Vreugdenhil, A.J., and Balbyshev, V.N., “Nanostructured Silicon Sol-Gel Surface Treatments for Al 2024-T3 Protection,”Journal of Coatings Technology,73, No. 915, 35 (2001).Google Scholar
  44. (22) (a).
    Metroke, T.L., Parkhill, R.L., and Knobbe, E.T., “Synthesis of Hybrid Organic-Inorganic Sol-Gel Coatings for Corrosion Resistance,”Mater. Res. Soc. Symp. Proc., 576, 293 (1999);Google Scholar
  45. (22) (b).
    Metroke, T.L., and Knobbe, E.T., “Crosslinked Organic-Inorganic Hybrid Thin Films for Corrosion Resistance: Spectroscopic and Salt Spray Characterization,”Mater. Res. Soc. Symp. Proc., 628, CC11.4.1 (2000).Google Scholar
  46. (23).
    Kachuri, O., Metroke, T.L., Stesikova, E., and Knobbe, E.T., “Comparison of Single and Multilayer Coatings Based on Ormosil and Conversion Layers for Aluminum Alloy Corrosion Inhibition,”Journal of Coatings Technology,74, No. 926, 43 (2002).CrossRefGoogle Scholar
  47. (24).
    Kabasakaloglu, M., Aydin, H., Aydin, H., and Aksu, M.L., “Inhibitors for the Protection of Aerospace Aluminum Alloy,”Materials and Corrosion, 48, 744 (1997).CrossRefGoogle Scholar
  48. (25).
    Parkhill, R.L., Knobbe, E.T., and Donley, M.S., “Application and Evaluation of Environmentally Compliant Spray-Coated Ormosil Films as Corrosion Resistant Treatments for Aluminum 2024-T3,”Prog. Org. Coat., 41, 261 (2001).CrossRefGoogle Scholar
  49. (26).
    Carey, F.A. and Sundberg, R.J.,Advanced Organic Chemistry, Plenum Press, New York, p. 540, 1977.Google Scholar

Copyright information

© Springer Science+Business Media 2002

Authors and Affiliations

  • Tammy L. Metroke
    • 1
  • Olga Kachurina
    • 1
  • Edward T. Knobbe
    • 1
  1. 1.Oklahoma State UniversityUSA

Personalised recommendations