Journal of Materials Science

, Volume 33, Issue 9, pp 2269–2281 | Cite as

Effect of inclusions on the tensile properties of Al–7% Si–0.35% Mg (A356.2) aluminium casting alloy

  • L Liu
  • F.H Samuel


The present study was performed on an A356.2 alloy. Two types of initial materials were used, i.e. fresh and recycled. A total of 13 operations representing those normally applied in aluminium foundries were simulated under dry atmospheric conditions (humidity ∼15%–20%). The molten metal was cast into test bars which were T6 tempered prior to tensile testing. The results show that holding the liquid metal for a long time, i.e. 72 h at 735°C leads to sedimentation of most inclusions towards the bottom of the melting crucible. However, a change in the surrounding humidity may cause absorption of hydrogen and, hence, a large amount of porosity. Degassing using dry argon injected into the liquid metal through a rotary impeller (speed ∼ 160 r.p.m) appears to be the best technique for inclusion removal. The efficiency of this process is significantly improved when it is coupled with filtration using ceramic foam filters (10 and 20 p.p.i). A linear relationship between alloy ductility and logarithm of percentage inclusions has been established. Owing to decohesion between the inclusions/oxide films and the surrounding matrix, cracks are easily initiated at their interfaces, leading to unpredicted failure. © 1998 Chapman & Hall


Foam Liquid Metal Casting Alloy Surrounding Matrix Aluminium Casting 
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  1. 1.
    W. Simmons, Indian Foundry J. August (1986) 21.Google Scholar
  2. 2.
    C. J. Simensen and G. Berg, Aluminium 56 (1980) 335.Google Scholar
  3. 3.
    D. Apelian, in “1988 Electric Furnace Conference Proceedings”, (Iron and Steel Society, Warrendale, PA, 1989) p. 325.Google Scholar
  4. 4.
    D. Apelian, R. Mutharasan and S. Ali, J. Mater. Sci. 20 (1985) 3501.Google Scholar
  5. 5.
    H. C. Cummings, F. B. Stulen and W. C. Schulte, Trans. Amer. Soc. Metals 49 (1957) 487.Google Scholar
  6. 6.
    C. E. Eckert, R. E. Miller, D. Apelian and R. Mutharasan, Light Metals (1984) 1281.Google Scholar
  7. 7.
    C. J. Simensen, Metall. Trans. 12B (1981) 733.Google Scholar
  8. 8.
    J. Gobrecht, Geisserei 62 (1975) 263.Google Scholar
  9. 9.
    F. H. Samuel, H. Liu and A. M. Samuel, Metall. Trans. 24A (1993) 1631.Google Scholar
  10. 10.
    J. E. Campbell, “Castings” (Butterworth-Heinemann, Oxford, 1991).Google Scholar
  11. 11.
    D. Hedjazi, G. H. J. Bennett and V. Kondic, Metall. Technol. 3 (1976) 537.Google Scholar
  12. 12.
    Idem, Br. Foundryman 68 (1975) 305.Google Scholar
  13. 13.
    K. Arai, T. Onishi, . Goto and R. Otsuka, J. Jpn Inst. Light Metals 27 (1977) 319.Google Scholar
  14. 14.
    P. R. Rios, J. C. Bruno and A. S. M. Fonseca, J. Mater. Sci. Lett. 10 (1991) 1346.Google Scholar
  15. 15.
    K. H. Chien, T. Z. Kattamis and F. R. Mollard, Metall. Trans. 4A (1973) 1069.Google Scholar
  16. 16.
    V. Gerold, in “Fourth International Conference on Age-Hardenable Aluminium Alloys”, Balatonfured, Hungary, May 1985, Materials Science Forum 13–14 (1987) pp. 175-94.Google Scholar
  17. 17.
    C. E. Eckert, R. E. Miller, D. Apelian and R. Mutharasan, Light Metals (1984) 1281.Google Scholar
  18. 18.
    D. Apelian and R. Mutharasan, J. Metals 32 (1980) 14.Google Scholar
  19. 19.
    D. Apelian and R. Mutharasan, “Modelling of Inclusion Removal of Melt Systems”, presented at the 72th Annual AIChE Meeting, San Francisco, CA, November 1979.Google Scholar
  20. 20.
    C. J. Simensen and U. Hartvedt, Z. Metallkde 76 (1985) 409.Google Scholar
  21. 21.
    L. J. Gauckler, M. M. Weber, C. Conti and M. Jacob-Duliere, Light Metals (1985) 1261.Google Scholar
  22. 22.
    T. Callais, M. Richard and M. Stucky, Fonderie-Fondeur d'aujourd'hui 97 (1990) 22.Google Scholar
  23. 23.
    L. F. Mondolfo, “Grain Refinement in Castings and Welds” (Metallurgical Society of AIME, 1983) pp. 3-50.Google Scholar
  24. 24.
    M. M. Gozowski, D. A. Senter and G. K. Sigworth, Metall. Trans. 18A (1987) 603.Google Scholar
  25. 25.
    G. K. Sigworth and M. M. Gozowski, Amer. Foundrymen's Soc. Trans. 93 (1985) 907.Google Scholar
  26. 26.
    S. Kennerknecht, in “Advanced Casting Technology”, AGARD Conference Proceedings No. 325, Advisory Group for Aerospace Research and Development, North Atlantic Treaty Organization [AGARD/NATO], Brussels, Belgium, 4-9 April 1982, pp. 1-52.Google Scholar
  27. 27.
    S. Z. Lu and A. Hellawell, Metall. Trans. 18A (1987) 1721.Google Scholar
  28. 28.
    D. Apelian, G. K. Sigworth and K. R. Whaler, Amer. Foundrymen's Soc. Trans. 92 (1988) 297.Google Scholar
  29. 29.
    R. Dasgupta, C. G. Brown and S. Marek, ibid. 96 (1988) 297.Google Scholar
  30. 30.
    P. D. Hess and E. V. Blackmun, ibid. 84 (1975) 87.Google Scholar
  31. 31.
    M. Garat and R. Scalliet, ibid. 84 (1978) 549.Google Scholar
  32. 32.
    L. Liu and F. H. Samuel, J. Mater. Sci. 33 (1997) 5901.Google Scholar
  33. 33.
    Idem, ibid. 33 (1997) 5927.Google Scholar

Copyright information

© Chapman and Hall 1998

Authors and Affiliations

  • L Liu
    • 1
  • F.H Samuel
    • 1
  1. 1.Departement des Sciences appliqueesUniversite du Quebec a ChicoutimiChicoutimiCanada

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