Skip to main content
SpringerLink
Log in

The influence of precipitation on the work-hardening behavior of the aluminum alloys AA6111 and AA7030

  • Published:
Metallurgical and Materials Transactions A Aims and scope Submit manuscript

Abstract

Tensile tests were conducted on the aluminum alloy, AA6111, after various artificial aging treatments in order to examine the influence of precipitation state on yield stress and work-hardening behavior. During artificial aging, significant changes in the work-hardening rate were observed as the precipitation reaction proceeded. A semiempirical model has been developed to interpret these changes in work-hardening rate. This model shows that the significant changes in work-hardening rate can be related to the manner in which flow stress contributions from different obstacles are summed and the transition from shearable to nonshearable precipitates. The present study presents a new approach to determining the shearable/nonshearable transition from a series of tensile tests. Results on the aluminum alloy AA7030 were also found to be consistent with the proposed theoretical framework. Finally, the proposed model allows the overall mechanical response for a variety of aging conditions to be rationalized.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

α D :

constant relating to the storage of geometrically necessary dislocations

α ⊥ :

constant in the relationship between dislocation density and flow stress

b :

magnitude of the Burgers vector

k 1 :

dislocation storage rate term due to statistically stored dislocations

k 2 :

dislocation storage rate term due to dynamic recovery

k D :

dislocation storage rate term due to geometrically necessary dislocations

f, f s , f ns :

constants representing the modification of the dynamic recovery due to precipitate effects; subscripts s and ns refer to shearable and nonshearable precipitates

F :

strength of nonshearable precipitates

G :

shear modulus

L :

spacing of precipitates on the glide plane

M :

Taylor factor

n :

exponent used in flow stress addition law

ε :

total strain

ε P :

plastic strain

ρ :

dislocation density

σ :

overall total flow stress of the alloy

σ ss :

solid solution contribution to flow stress

σ ppt :

precipitation-hardening contribution to flow stress

σ Y :

yield stress

σ ⊥ :

dislocation hardening contribution to flow stress

σ ⊥s :

saturation stress for dislocation hardening contribution

T :

line tension of the dislocation=G b 2/2

θ ⊥ :

work-hardening rate for dislocation hardening

θ ⊥o :

initial work-hardening rate for dislocation contribution to flow stress

θ :

overall work-hardening rate of alloy

θ max :

overall initial work-hardening rate of alloy as defined in Fig. 3

dθ/dσ :

as defined in Fig. 3

References

  1. S.J. Basinski and Z.S. Basinski: in Dislocations in Solids, F.R.N. Nabarro, ed., North-Holland, Amsterdam, 1979, vol. 4, pp. 261–362.

    Google Scholar 

  2. Y. Estrin: in Unified Constitutive Laws of Plastic Deformation, A.S. Krausz and K. Krausz, eds., Academic Press New York, NY, 1996, pp. 69–106.

    Google Scholar 

  3. U.F. Kocks: J. Eng. Mater. Technol., 1976, vol. 98, pp. 76–85.

    CAS  Google Scholar 

  4. H. Mecking and U.F. Kocks: Acta Metall., 1981, vol. 29, pp. 1865–75.

    Article  CAS  Google Scholar 

  5. J.G. Sevillano: in Materials Science and Technology, A Comprehensive Treatment, R.W. Cahn, P. Haasen, and E.J. Kramer, eds., VCH, Weinheim, 1993, vol. 6, pp. 19–88.

    Google Scholar 

  6. E. Nes: Progr. Mater. Sci., 1997, vol. 41 (3), pp. 129–93.

    Article  CAS  Google Scholar 

  7. K. Marthinsen and E. Nes: Mater. Sci. Eng. A, 1997, vols. 234–236, pp. 1095–98.

    Google Scholar 

  8. U.F. Kocks: Metall. Trans. A, 1985, vol. 16A, pp. 2109–29.

    CAS  Google Scholar 

  9. M.Z. Butt and P. Feltham: J. Mater. Sci., 1993, vol. 28, pp. 2557–76.

    Article  CAS  Google Scholar 

  10. N. Ryum and J.D. Embury: Scand. J. Metall., 1982, vol. 11, pp. 51–54.

    CAS  Google Scholar 

  11. J.G. Byrne, M.E. Fine, and A. Kelly: Phil. Mag., 1961, vol. 6, pp. 1119–45.

    CAS  Google Scholar 

  12. E. Hornbogen and K-H.Z. Gahr: Metallography, 1975, vol. 8, pp. 181–202.

    Article  CAS  Google Scholar 

  13. M.F. Ashby: Phil. Mag., 1970, vol. 21, pp. 399–424.

    CAS  Google Scholar 

  14. L.M. Brown and W.M. Stobbs: Phil. Mag., 1971, vol. 23, pp. 1185–99.

    CAS  Google Scholar 

  15. J.D. Embury: Metall. Trans. A, 1985, vol. 16A, pp. 2191–200.

    Google Scholar 

  16. A.J. Foreman and M.J. Makin: Phil. Mag., 1966, vol. 14, pp. 911–24.

    CAS  Google Scholar 

  17. U.F. Kocks: in Unified Constitutive Equations for Creep and Plasticity, A.K. Miller, ed., Elsevier, London, 1987, pp. 1–88.

    Google Scholar 

  18. U.F. Kocks, A.S. Argon, and M.F. Ashby: in Progress in Materials Science, B. Chalmers, J.W. Christian, and T.B. Massalski, eds., Pergamon, Oxford, United Kingdom, 1975, vol. 19.

    Google Scholar 

  19. A.W. Zhu and E.A. Starke, Jr: Acta Mater., 1999, vol. 47 (11), pp. 3263–69.

    Article  CAS  Google Scholar 

  20. U.F. Kocks: Proc. 5th Int. Conf. on Strength of Metals and Alloys, P. Haasen, V. Gerold, and G. Kostorz, eds., Pergamon Press, Oxford, UK, 1979, pp. 1661–80.

    Google Scholar 

  21. J.T. Staley: Aluminum Alloys: Their Physical and Mechanical Properties, L. Arnberg, O. Lohne, E. Nes, and N. Ryum, eds., SINTEF, Trondheim, Norway, 1992, pp. 115–16.

    Google Scholar 

  22. M.F. Ashby: Strengthening Methods in Crystals, A. Kelly and R.B. Nicholson, eds., John Wiley & Sons, New York, NY, 1971, pp. 137–92.

    Google Scholar 

  23. L.M. Brown and R.K. Ham: Strengthening Methods in Crystals, A. Kelly and R.B. Nicholson, eds., John Wiley & Sons, New York, NY, 1971, pp. 12–135.

    Google Scholar 

  24. M. Vivas, P. Lours, C. Levaillant, A. Couret, M.J. Casanove, and A. Coujou: Mater. Sci. Eng. A, 1997, vol. 234–236, pp. 664–67.

    Google Scholar 

  25. S. Esmaeili, D.J. Lloyd, and W.J. Poole: Acta Mater., 2003, vol. 51, pp. 2243–57.

    Article  CAS  Google Scholar 

  26. W.F. Miao and D.E. Laughlin: Metall. Mater. Trans. A, 2000, vol. 31A, pp. 361–71.

    CAS  Google Scholar 

  27. M. Murayama, K. Hono, W.F. Miao, and D.E. Laughlin: Metall. Mater. Trans. A, 2001, vol. 32A, pp. 239–46.

    CAS  Google Scholar 

  28. D.J. Lloyd, D.R. Evans, and A.K. Gupta: Can. Metall. Q. 2000, vol. 39, pp. 475–82.

    CAS  Google Scholar 

  29. A. Perovic, D.D. Perovic, G.C. Weatherly, and D.J. Lloyd: Scripta Mater., 1999, vol. 41, pp. 703–08.

    Article  CAS  Google Scholar 

  30. X. Wang, W.J. Poole, S. Esmaeili, D.J. Lloyd, and J.D. Embury: Metall. Mater. Trans. A, in press.

  31. A. Deschamps and Y. Brechet: Acta Mater., 1999, vol. 47 (1), pp. 293–305.

    Article  CAS  Google Scholar 

  32. W.J. Poole, J.A. Sæter, S. Skjervold, and G. Waterloo: Metall. Mater. Trans. A, 2000, vol. 31A, pp. 2327–38.

    CAS  Google Scholar 

Download references

Author information

Author notes

  1. L. M. Cheng (Postdoctoral Fellow)

    Present address: the Department of Metals and Materials Engineering, The University of British Columbia, V6T 1Z4, Vancouver, BC, Canada

Authors and Affiliations

  1. Defence R&D Canada, Atlantic Emerging Materials Section, B3K 5X5, Halifax, NS, Canada

    L. M. Cheng (Postdoctoral Fellow)

  2. the Department of Metals and Materials Engineering, The University of British Columbia, V6T 1Z4, Vancouver, BC, Canada

    W. J. Poole (Associate Professor)

  3. the Department of Materials Science and Engineering, McMaster University, L8S 4L7, Hamilton, ON, Canada

    J. D. Embury (Professor)

  4. the Kingston Research & Development Centre, Alcan International, K7L 5L9, Kingston, ON, Canada

    D. J. Lloyd (Principal Scientist)

Authors
  1. L. M. Cheng
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. W. J. Poole
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. J. D. Embury
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. D. J. Lloyd
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Cheng, L.M., Poole, W.J., Embury, J.D. et al. The influence of precipitation on the work-hardening behavior of the aluminum alloys AA6111 and AA7030. Metall Mater Trans A 34, 2473–2481 (2003). https://doi.org/10.1007/s11661-003-0007-2

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11661-003-0007-2

Keywords

Search

Navigation