Techniques for Improved Surface Integrity of Aerospace Aluminum Alloys

  • W. Wallace
  • M. D. Raizenne
  • A. Ankara


The optimum performance of aerospace components and structures usually depends on the achievement of high strength, high fatigue resistance and resistance to many forms of surface degradation including wear, fretting, corrosion and stress corrosion cracking. In the case of high strength aluminum alloys, trade-offs are often made between strength and corrosion resistance, such as those brought about by standard heat treatments T651 or T7351. The Retrogression and Re aging Process, first described by Cina et al. has shown that near surface properties can be modified by novel heat treatment procedures to obtain strength levels equivalent to the T651 temper together with stress corrosion resistance equivalent to that of the T7351 temper. This success has stimulated other work to investigate derivative heat treatments that might provide similar benefits in thick section parts. This paper reviews these new approaches to heat treatment and provides examples of the effects of these treatments on the properties of thick section parts with major dimensions up to 76 mm. The effects of processing on the microstructure conductivity, resistivity, yield strength, hardness, fatigue, corrosion fatigue and stress corrosion cracking of typical 7000 series alloys are described.


Crack Growth Rate Stress Corrosion Crack Closure Fatigue Crack Growth Rate Corrosion Fatigue 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Wallace, W., Hoeppner, D.W., and Kandachar, P.V., AGARD Corrosion Handbook Volume 1, Aircraft Corrosion: Causes and Case Histories, AGARD-AG-278 Volume 1, July 1985.Google Scholar
  2. 2.
    Cina, B.M. and Ranish, B., New technique for reducing susceptibility to stress corrosion of high strength aluminum alloys, in Aluminum Industrial Products, Pittsburgh Chapter, American Society for Metals, 1974.Google Scholar
  3. 3.
    Cina, B.M., Reducing the susceptibility of alloys, particularly aluminium alloys, to stress corrosion cracking, U.S. Patent 3,856,584, December 24, 1974.Google Scholar
  4. 4.
    Ankara, A., Durlu, N., and Wallace, W., Kinetics of retrogression and reaging of 7075 aluminum alloy, Turkish Journal of Engineering and Environment, 1988, 12, 3, 302–309.Google Scholar
  5. 5.
    Islam, M.U. and Wallace, W., Retrogression and reaging response of 7475 aluminium alloy, Metals Technology, 1983, 10, 386–392.CrossRefGoogle Scholar
  6. 6.
    Wallace, W., Beddoes, J.C. and deMalherbe, M.C., A new approach to the problem of stress corrosion cracking in 7075-T6 aluminum, Canadian Aeronautics and Space Journal, 1981, 27 (3), 222–232.Google Scholar
  7. 7.
    Islam, M.U. and Wallace, W., Stress corrosion crack growth behaviour of 7475-T6 retrogressed and reaged aluminium alloy, Metals Technology, 1984, 11, 320–322.CrossRefGoogle Scholar
  8. 8.
    Kaneko, R.S., RRA: Solution for Stress Corrosion Problems with T6 Temper Aluminum, Metal Progress, April 1980, 117, 41–43.Google Scholar
  9. 9.
    Brown, M.H., Producing combined high strength and high corrosion resistance in Al-Zn-Mg-Cu Alloys, U.S. Patent 4,832,758, May 23, 1989.Google Scholar
  10. 10.
    Thompson, J.J., Tankins, E.S. and Agarwala, V.S., A heat treatment for reducing corrosion and stress corrosion cracking susceptibilities in 7XXX Al Alloys, Paper No. 204, Conf. Corrosion 86, Nat. Assoc. of Corr. Eng., Houston, TX, Mar. 17–21, 1986.Google Scholar
  11. 11.
    Thompson, J.J., Tankins, E.S., and Agarwala, V.S., Stress corrosion cracking resistant heat treatment for 7000 series aluminum alloys — RRA, Naval Air Development Center, Warminster, PA, 1987, unpublished work.Google Scholar
  12. 12.
    Hyatt, M.V., Use of precracked specimens in stress corrosion testing of high strength aluminum alloys. Corrosion, 1970, 26, 11, 487–503.CrossRefGoogle Scholar
  13. 13.
    Baldantoni, A., Corrosion sous tension et fatigue-corrosion des materiaux structuraux aeronautiques, thesis submitted in partial fulfillment of the requirement of Master of Applied Science, Department of Metallurgical Engineering, Ecole Polytechnique, University of Montreal, June 1985.Google Scholar
  14. 14.
    Baldantoni, A., Wallace, W., Raizenne, M.D. and Dickson, J.Y., The NRC contribution to the FACT programme, in AGARD Report No. 713, The Fatigue in Aircraft Corrosion Testing (FACT) Programme. February 1989.Google Scholar
  15. 15.
    Raizenne, M.D., KRAKS — an MTS Basic 770 computer program for automated fatigue crack growth rate testing, NAE-NRC Report LTR-ST-1538, February 1986.Google Scholar
  16. 16.
    Park, J.K. and Ardell, A.J., Effect of retrogression and reaging treatments on the Microstructure of Al 7075-T651, Met. Trans., 1984, 15A, 1531–1543.CrossRefGoogle Scholar
  17. 17.
    Park, J.K. and Ardell, A.J., Precipitate microstructure of peak-aged 7075 Al, Scripta Met., 1988, 22, 1115–1119.CrossRefGoogle Scholar
  18. 18.
    Danh, N.G., Rajan, K., and Wallace, W., A TEM study of microstructural changes during retrogression and reaging in 7075 aluminum, Met. Trans., 1983, 14A, 1843–1849.CrossRefGoogle Scholar
  19. 19.
    Talianker, M. and Cina, B., Retrogression and reaging and the role of dislocations in the stress corrosion of 7000 — type aluminum alloys, Met. Trans., 1989, 20A, 2087–2092.CrossRefGoogle Scholar
  20. 20.
    Rajan, K., Wallace, W. and Beddoes, J.C., Microstructural study of a high strength stress corrosion resistant 7075 aluminum alloy, J. Mat. Sci, 1982, 17, 2817–2824.CrossRefGoogle Scholar
  21. 21.
    Christodoulou, L. and Flower, H.M., Hydrogen embrittlement and trapping in Al-6%Zn-3%Mg, Acta Met., 1980, 28, 481–487.CrossRefGoogle Scholar
  22. 22.
    Seamans, G.M., Hydrogen bubbles in embrittled Al-Zn-Mg alloys, J. Mat. Sci., 1978, 13, 27–36.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1990

Authors and Affiliations

  • W. Wallace
    • 1
  • M. D. Raizenne
    • 1
  • A. Ankara
    • 2
  1. 1.National Aeronautical EstablishmentOttawaCanada
  2. 2.Middle East Technical UniversityAnkaraTurkey

Personalised recommendations