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Metallurgical and Materials Transactions A

, Volume 40, Issue 7, pp 1716–1726 | Cite as

Rapid Heat Treatment of Aluminum High-Pressure Diecastings

  • R. N. LumleyEmail author
  • I. J. Polmear
  • P. R. Curtis
Article

Abstract

Recently, it has been demonstrated that common high-pressure diecasting (HPDC) alloys, such as those based on the Al-Si-Cu and Al-Si-Mg-(Cu) systems, may be successfully heat treated without causing surface blistering or dimensional instability. In some compositions, the capacity to exploit age hardening may allow the proof stress values to be doubled when compared to the as-cast condition. This heat treatment procedure involves the use of severely truncated solution treatment cycles conducted at lower than normal temperatures, followed by quenching and natural or artificial aging. The potential therefore exists to develop and evaluate secondary HPDC alloys designed specifically for rapid heat treatment, while still displaying high castability. This article reports results of an experimental program in which responses of various alloy compositions to age hardening have been investigated with the primary aim of further reducing the duration and cost of the heat treatment cycle while maintaining high tensile properties. Composition ranges have been established for which values of 0.2 pct proof stress exceeding 300 MPa (i.e., increases of ~100 pct above as-cast values) can be achieved using a procedure that involves a total time for solution treatment plus age hardening of only 30 minutes. This rapid aging behavior is shown to be related to precipitation of the complex Q′ phase, which forms primarily when Mg contents of the alloys are above ~0.2 wt pct.

Keywords

Habit Plane Artificial Aging Peak Hardness Heat Treatment Cycle Differential Scanning Calorimeter Result 
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.

Notes

Acknowledgments

The authors thank Andy Yob, Maya Gershenzon, and Dayalan Gunasegaram for assistance with diecasting of test samples.

References

  1. 1.
    R.N. Lumley, R.G. O’Donnell, D.R. Gunasegaram, and M. Givord: International Patent Application WO2006/066314, 2005.Google Scholar
  2. 2.
    R.N. Lumley, R.G. O’Donnell, D.R. Gunasegaram, and M. Givord: Metall. Mater. Trans. A, 2007, vol. 38A, pp. 2564–74.CrossRefADSGoogle Scholar
  3. 3.
    R.N. Lumley, R.G. O’Donnell, D.R. Gunasegaram, and M. Givord: Mater. Sci. Forum, 2006, vols. 519–522, pp. 351–59.CrossRefGoogle Scholar
  4. 4.
    R.N. Lumley, R.G. O’Donnell, D.R. Gunasegaram, and M. Givord: 13th ADCA Conf. Proc., Melbourne, Australia, 2006, Australian Die Casting Association (ADCA), Melbourne, Australia, paper no. 25.Google Scholar
  5. 5.
    R.N. Lumley, D.R. Gunasegaram, M. Gershenzon, and R.G. O’Donnell: Conf. Proc. 111th Metalcasting Congr., Houston, TX, 2007, North American Diecasting Association (NADCA), Wheeling, IL, paper no. T07-013.Google Scholar
  6. 6.
    R.N. Lumley, R.G. O’Donnell, D.R. Gunasegaram, and M. Givord: Geissereiforschung, 2007, vol. 59 (3), pp. 8–13.Google Scholar
  7. 7.
    R.N. Lumley: Conf. Proc. 2008 SAE Small Engine Technology Conf., Milwaukee, WI, 2008, paper nos. 2008-32-0058 (SAE) and 20084758 (JSAE).Google Scholar
  8. 8.
    R.N. Lumley and S. Tartaglia: Conf. Proc. 111th Metalcasting Congr., Houston, TX, 2007, North American Diecasting Association (NADCA), Wheeling, IL, paper no. T07-023.Google Scholar
  9. 9.
    R.N. Lumley and J.R. Griffiths: Adv. Mater. Res., 2008, vols. 41–42, pp. 141–46.CrossRefGoogle Scholar
  10. 10.
    R.N. Lumley: Adv. Mater. Res., 2008, vols. 41–42, pp. 99–104.CrossRefGoogle Scholar
  11. 11.
    R.N. Lumley, I.J. Polmear, H. Groot, and J. Ferrier: Scripta Mater., 2008, vol. 58, pp. 1006–09.CrossRefGoogle Scholar
  12. 12.
    J. Buha, R.N. Lumley, and A.J. Crosky: Phil. Mag., 2008, vol. 88 (3), pp. 373–90.CrossRefADSGoogle Scholar
  13. 13.
    D.J. Chakrabati and D.E. Laughlin: Prog. Mater. Sci., 2004, vol. 49, pp. 389–410.CrossRefGoogle Scholar
  14. 14.
    H.J. Axon: J. Inst. Met., 1952–53, vol. 81, pp. 209–13.Google Scholar
  15. 15.
    L.A. Willey: in Aluminum, vol. 1, Properties, Physical Metallurgy and Phase Diagrams, K. van Horn, ed., ASM INTERNATIONAL, Metals Park, OH, 1967, Appendix 1, p. 394.Google Scholar
  16. 16.
    L. Sagalowicz, G. Hug, D. Bechet, P. Sainfort, and G. Lapasset: Conf. Proc. ICAA4, Atlanta, GA, 1994, Georgia Institute of Technology, School of Materials Science and Engineering, Atlanta, GA, pp. 636–43.Google Scholar
  17. 17.
    S. Esmaeili, X. Wang, D.J. Lloyd, and W.J. Poole: Metall. Mater. Trans. A, 2003, vol. 34A, pp. 751–63.ADSGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2009

Authors and Affiliations

  1. 1.CSIRO Light Metals FlagshipClayton South MDCAustralia

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