Skip to main content
SpringerLink
Log in

Effect of Mg and Sr additions on the formation of intermetallics in Al-6 Wt pct Si-3.5 Wt pct Cu-(0.45) to (0.8) Wt pct Fe 319-type alloys

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

Abstract

Al-Si alloys are materials that have been developed over the years to meet the increasing demands of the automotive industry for smaller, lighter-weight, high-performance components. An important alloy in this respect is the 319 alloy, wherein silicon and copper are the main alloying elements, and magnesium is often added in automotive versions of the alloy for strengthening purposes. The mechanical properties are also ameliorated by modifying the eutectic silicon structure (strontium being commonly employed) and by reducing the harmful effect of the β-Al5FeSi iron intermetallic present in the cast structure. Magnesium is also found to refine the silicon structure. The present study was undertaken to investigate the individual and combined roles of Mg and Sr on the morphologies of Si, Mg2Si, and the iron and copper intermetallics likely to form during the solidification of 319-type alloys at very slow (close to equilibrium) cooling rates. The results show that magnesium leads to the precipitation of Al8Mg3FeSi6, Mg2Si, and Al5Mg8Cu2Si6 intermetallics. With a strontium addition, dissolution of a large proportion of the needle-like β-Al5FeSi intermetallic in the aluminum matrix takes place; no transformation of this phase into any other intermetallics (including the Al15(Fe,Mn)3Si2 phase) is observed. When both Mg and Sr are added, the diminution of the β-Al5FeSi phase is enhanced, through both its dissolution in the aluminum matrix as well as its transformation into Al8Mg3FeSi6. The reactions and phases obtained have been analyzed using thermal analysis, optical microscopy, image analysis, and electron microprobe analysis (EMPA) coupled with energydispersive X-ray (EDX) analysis.

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

References

  1. G.K. Sigworth, S. Shivkumar, and D. Apelian: AFS Trans., 1989, vol. 97, pp. 811–24.

    Google Scholar 

  2. L. Backerud, G. Chai, and J. Tamminen: Solidification Characteristics of Aluminum Alloys, Vol. 2: Foundry Alloys, AFS/Skanaluminium, Des Plaines, IL, 1990, pp. 71–229.

    Google Scholar 

  3. A.M. Samuel, J. Gauthier, and F.H. Samuel: Metall. Mater. Trans. A, 1996, vol. 27A, pp. 1785–98.

    CAS  Google Scholar 

  4. S. Murali, K.S. Raman, and K.S.S. Murthy: Mater. Characterization, 1994, vol. 33, pp. 99–112.

    Article  CAS  Google Scholar 

  5. J. Gobrecht: Giesserei, 1976, vol. 63, pp. 558–61.

    CAS  Google Scholar 

  6. L.R. Morris and F.B. Miners: U.S. Patent No. 3, 926, 690, 1975.

  7. M.H. Mulazimoglu, A. Zaluska, J.E. Gruzleski, and F. Paray: Metall. Mater. Trans. A, 1996, vol. 27A, pp. 929–36.

    CAS  Google Scholar 

  8. F.H. Samuel and A.M. Samuel: Proc. Int. Symp. on Light Metals 1997, 36th Annual Conference of Metallurgists of CIM, Sudbury, ON, Aug. 17–20, 1997, pp. 425–37.

  9. A. Pennors, A.M. Samuel, F.H. Samuel, and H.W. Doty: AFS Trans., 1998, vol 106, paper no. 98–105, in press.

  10. A.M. Samuel, H.W. Doty, and F.H. Samuel: J. Mater. Sci., 1996, vol. 31, pp. 5529–39.

    Article  CAS  Google Scholar 

  11. J.E. Gruzleski and B.M. Closset: The Treatment of Liquid Aluminum-Silicon Alloys, American Foundrymen’s Society, Inc., Des Plaines, IL, pp. 25–126.

  12. J. Sakwa: Giesserei-Forschung, 1986, vol. 38, pp. 112–18.

    CAS  Google Scholar 

  13. S. Bercovici: “Control of Solidification Structure and Properties of Al-Si Alloys,” Presentation at 45th International Foundry Congress, 1978.

  14. H. de la Sablonniere and F.H. Samuel: Int. J. Cast Met. Res., 1996, vol. 9 (4), pp. 195–211 and pp. 213–25.

    Google Scholar 

  15. P. Ouellet: Master’s Thesis, UQAC, Chicoutimi, 1997.

    Google Scholar 

  16. L.F. Mondolfo: Aluminum Alloys: Structure and Properties, Butterworth and Co., London, 1978, pp. 759–65.

    Google Scholar 

  17. A.M. Samuel and F.H. Samuel: Int. J. Cast Met. Res., 1997, vol. 10, pp. 147–57.

    CAS  Google Scholar 

  18. S.C. Flood, P.V. Evans, J.M. Brown, and J. Worth: in Light Metals 1995, J. Evans, ed., TMS, Warrendale, PA, pp. 1127–35.

  19. S.G. Shabestari: Ph.D. Thesis, McGill University, Montreal, 1995.

    Google Scholar 

  20. D.A. Granger: AFS Trans., 1991, vol. 99, pp. 379–83.

    CAS  Google Scholar 

Download references

Author information

Author notes

  1. P. Ouellet (Graduate Student, Engineer)

    Present address: the Department of Applied Sciences, University of Quebec at Chicoutimi, G7H 2B1, Chicoutimi, PQ, Canada

Authors and Affiliations

  1. the Department of Applied Sciences, University of Quebec at Chicoutimi, G7H 2B1, Chicoutimi, PQ, Canada

    F. H. Samuel (Professor) & A. M. Samuel (Research Associate)

  2. Montupet Ltée, Rivière-Beaudette, J0P 1R0, PQ, Canada

    P. Ouellet (Graduate Student, Engineer)

  3. General Motors Corporation, GM Powertrain/MCT, 03055, Milford, NH

    H. W. Doty (Materials Engineer)

Authors
  1. F. H. Samuel
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. M. Samuel
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. P. Ouellet
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. H. W. Doty
    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

Samuel, F.H., Samuel, A.M., Ouellet, P. et al. Effect of Mg and Sr additions on the formation of intermetallics in Al-6 Wt pct Si-3.5 Wt pct Cu-(0.45) to (0.8) Wt pct Fe 319-type alloys. Metall Mater Trans A 29, 2871–2884 (1998). https://doi.org/10.1007/s11661-998-0194-y

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11661-998-0194-y

Keywords

Search

Navigation