Advertisement

Metallurgical and Materials Transactions A

, Volume 35, Issue 5, pp 1425–1435 | Cite as

The solidification characteristics of Fe-rich intermetallics in Al-11.5Si-0.4Mg cast alloys

  • X. Cao
  • J. Campbell
Article

Abstract

After the nucleation and sedimentation of primary Fe-rich phases, the microstructures of Al-11.5Si-0.4Mg cast alloys with 0.35–1.03Fe and 0.18–0.59Mn have been studied to investigate the solidification characteristics of Fe-rich phases. Depending on the iron and manganese contents as well as cooling rates, Fe-rich phases may solidify as predendritic (primary), pre-eutectic, coeutectic, and posteutectic intermetallics at the different stages of solidification through three types of reactions: (1) predendritic (primary), (2) eutectic, and (3) peritectic reactions. It seems that Fe-rich phases may nucleate on the wetted sides of double oxide films, while the gap of the dry sides of oxide films constitutes the cracks commonly observed in the Fe-rich phases and aluminum matrix. Conventional metallurgical observations also suggest that the Fe-rich phases nucleated early during the solidification might act as nuclei for those formed subsequently, although it has not been ruled out that these phases may share the same oxide substrates. It is probable that these nucleation events may all work as suggested in the possible nucleation hierarchy for Al-11.5Si-0.4Mg cast alloys.

Keywords

Material Transaction Oxide Film Cast Alloy Secondary Electron Image Chinese Script 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    J. Campbell: Casting, Butterworth-Heinemann, Oxford, United Kingdom, 1991.Google Scholar
  2. 2.
    J.R. Davis: ASM Speciality Handbook, ASM, Materials Park, OH, 1993, pp. 199–230.Google Scholar
  3. 3.
    D. Apelian: in Advances in Aluminium Casting Technology, M. Tiryakioglu and J. Campbell, eds., ASM International, OH, 1998, pp. 153–62.Google Scholar
  4. 4.
    X. Cao: Ph.D. Thesis, University of Birmingham, Birmingham, 2001.Google Scholar
  5. 5.
    X. Cao and J. Campbell: Materials Solutions 2002—Advances in Aluminium Casting Technology II, Columbus, OH, Oct. 7–10, 2002, ASM International, Materials Park, OH, 2002, pp. 135–46.Google Scholar
  6. 6.
    X. Cao and J. Campbell: AFS Trans., 2000, vol. 108, pp. 391–400.Google Scholar
  7. 7.
    X. Cao and J. Campbell: Int. J. Cast Met. Res., 2000, vol. 13 (3), pp. 175–84.Google Scholar
  8. 8.
    X. Cao and J. Campbell: AFS Trans., 2001, vol. 109, pp. 501–15.Google Scholar
  9. 9.
    X. Cao and J. Campbell: Int. J. Cast Met. Res., 2003, vol. 15, pp. 595–608.Google Scholar
  10. 10.
    X. Cao and J. Campbell: Metall. Mater. Trans. A, 2003, vol. 34A, pp. 1409–20.CrossRefGoogle Scholar
  11. 11.
    K. Werfers and C. Misra: Alcoa Technical Paper No. 19 (Revised), “Oxides and Hydroxides of Aluminum”, Alcoa Laboratories, Aloca, PA, 1987.Google Scholar
  12. 12.
    L. Backerud, G. Chai, and J. Tamminen: Solidification Characteristics of Aluminium Alloys, Foundry Alloys, AFS/Skanaluminum, Skanaluminium, Oslo, Norway, 1990, vol. 2, pp. 71–84.Google Scholar
  13. 13.
    H.S.H. Lo: Ph.D. Thesis, University of Birmingham, Birmingham, 1998.Google Scholar
  14. 14.
    J. Tamminen: Ph.D. Thesis, University of Stockholm, Stockholm, 1988, No. 2.Google Scholar
  15. 15.
    L.F. Mondolfo: Aluminium Alloys: Structure and Properties, Butterworth and Co., London, 1976, pp. 534–37.Google Scholar
  16. 16.
    L.F. Mondolfo: Manganese in Aluminium Alloys, The Manganese Centre, Neuilly sur Seine, France, 1978.Google Scholar
  17. 17.
    K.S. Tang and T. Sritharan: Mater. Sci. Technol., 1998, vol. 14, pp. 738–42.Google Scholar
  18. 18.
    J.E. Gruzleski: AFS Trans., 1992, vol. 100, pp. 673–83.Google Scholar
  19. 19.
    C.M. Allen, K.A.Q. O’Reilly, B. Cantor, and P.V. Evans: Process Mater. Sci., 1998, vol. 43, pp. 89–170.CrossRefGoogle Scholar
  20. 20.
    A. Couture: AFS Int. Casting Met. J., 1981, vol. 6 (4), pp. 9–17.Google Scholar
  21. 21.
    P.N. Crepeau: AFS Trans., 1995, vol. 103, pp. 361–66.Google Scholar

Copyright information

© ASM International & TMS-The Minerals, Metals and Materials Society 2004

Authors and Affiliations

  • X. Cao
    • 1
  • J. Campbell
    • 2
  1. 1.the Aerospace Manufacturing Technology CentreInstitute for Aerospace Research, National Research Council CanadaSt. LaurentCanada
  2. 2.the Department of Metallurgy and MaterialsUniversity of BirminghamBirminghamEngland

Personalised recommendations