Interdendritic fluid flow and macrosegregation; influence of gravity


An analysis is given of interdendritic flow behavior during solidification of castings and ingots, assuming resistance to flow is as in other types of porous media. Driving forces for the flow are solidification contractions and gravity acting on a fluid of variable density. Detailed flow calculations are given for horizontal, unidirectional, steady-state solidification, using aluminum-copper alloys as examples. Conditions are quantitatively described under which gravity induced convection becomes an important contributory cause of macrosegregation. A critical condition of flow is shown to produce local melting with resulting formation of “channel-type” segregates. Qualitative examples are given of application of the ideas presented to interpretation of macrosegregation in commercial ingots, with specific reference to centerline segregation and “channel-type” segregation, including “V” segregates, “A” segregates and “freckles”.

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  1. 1.

    M. C. Flemings and G. E. Nereo:Trans. TMS-AIME, 1967, vol. 239, pp. 1449–61.

    Google Scholar 

  2. 2.

    M. C. Flemings, R. Mehrabian, and G. E. Nereo:Trans. TMS-AIME, 1968, vol.242, pp. 41–49.

    Google Scholar 

  3. 3.

    M. C. Flemings and G. E. Nereo:Trans. TMS-AIME, 1968, vol. 242, pp. 50–55.

    Google Scholar 

  4. 4.

    R. Mehrabian and M. C. Flemings:Trans. Met. Trans., 1970, vol. 1, pp. 455–64.

    Article  Google Scholar 

  5. 5.

    R. J. McDonald and J. D. Hunt:Trans. TMS-AIME, 1969, vol. 245, pp. 1993–97.

    Google Scholar 

  6. 6.

    S. M. Copley, A. F. Giamei, S. M. Johnson, and M. F. Hornbecker:Met. Trans., 1970, vol. 1, in press.

  7. 7.

    M. Muskat:Flow of Homogeneous Fluids through Porous Media, McGraw-Hill, New York, 1937; J. W. Edwards, Inc., Ann Arbor, 1946.

    Google Scholar 

  8. 8.

    A. E. Scherdegger:The Physics of Flow through Porous Media, University of Toronto Press, 1957.

  9. 9.

    R. E. Collins:Flow of Fluids through Porous Materials, Reinhold Publishing Co., 1961.

  10. 10.

    E. Scheil:Metallforschung: 1947, vol. 2, p. 69.

    Google Scholar 

  11. 11.

    J. Preston: International Transactions Vacuum Metallurgy Conference, E.L. Foster, ed., American Vacuum Society, New York, 1968.

    Google Scholar 

  12. 12.

    E. C. Ellwood and J. M. Silcock:J. Inst. Metals, 1948, vol. 74, p. 457.

    Google Scholar 

  13. 13.

    V. E. Gebhardt, M. Becker, and S. Dorner:Aluminum, 1955, vol. 31, p. 315.

    Google Scholar 

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Mehrabian, R., Keane, M. & Flemings, M.C. Interdendritic fluid flow and macrosegregation; influence of gravity. Metall and Materi Trans 1, 1209–1220 (1970).

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  • Metallurgical Transaction
  • Mushy Zone
  • Flow Line
  • Liquid Density
  • Liquid Composition