Abstract
A model describing the development of dendritic structure and the resulting gradient of flow resistance to interdendritic liquid is presented. The Hagen–Pousielle version of D’Arcy’s equation for flow through a porous structure is developed as a function of cooling rate and liquid volume fraction. Applied to finite elements in a unidirectionally cooled casting model, permeability gradient, feeding flow-rate required to prevent porosity, and mushy-zone liquid pressure drop at this flow rate are evaluated for the simple Fe–2Cr–0.5C and Al–5Cu castings exhibiting asymptotic and linear temperature profiles, respectively. The model shows permeability of the dendritic structure in the mushy zone dropping sharply, approaching the root of solidification front (solidus). Also shown is the effect of relative magnitude of primary and secondary arm spacing. If secondary dendrite arm spacing approaches primary arm spacing, the permeability for flow normal to primary dendrite arms approaches or even surpasses the permeability for flow parallel to primary dendrite arms.
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References
Geiger GH, Poirier DR (1973) Transport phenomena in metallurgy. Addison-Wesley, Reading, p 91
Geiger GH, Poirier DR (1973) Transport phenomena in metallurgy. Addison-Wesley, Reading, p 45
Duncan AJ, Han Q, Viswanathan S (1999) Metall Mater Trans B 30B:745
Streat N, Weinberg F (1976) Interdendritic fluid flow in a lead–tin alloy. Metall Trans B 7B:417
Murakami K, Shiraishi A, Okamoto T (1983) Interdendritic fluid flow normal to primary dendrite-arms in cubic alloys. Acta Metall 31(9):1417
Nielsen O, Arnberg L, Mo A, Thevik H (1999) Experimental determination of mushy zone permeability in aluminum–copper alloys with equiaxed microstructures. Metall Mater Trans A 30A:2455
Wang CY, Ahuja S, Beckermann C, de Groh III HC (1995) Metall Mater Trans B 26B:111
Nasser-Rafi R, Desmunkh R, Poirier DR (1985) Flow of interdendritic liquid and permeability in Pb-20 Wt Pct Sn alloys. Metall Trans A 16A:2263
Santos RG, Melo MLNM (2005) Permeability of interdendritic channels. Mater Sci Eng A 391:151
Sabau AS, Viswanathan S (2002) Microporosity in aluminum alloy casting. Metall Mater Trans B 33B:243
Niyama E, Uchida T, Morikawa M, Saito S (1982) A method of shrinkage prediction and its application to steel casting practice. AFS International Cast Metals Journal, pp 52–63
Flemings MC (1974) Solidification processing, materials science and engineering series. McGraw-Hill, New York, NY, p 148
Bejan A, Dincer I, Lorente S, Miguel A, Reis H (2004) Porous and complex flow structures in modern technologies. Springer-Verlag, New York, p 10
Horwath JA, Mondolfo LF (1962) Dendritic growth. Acta Metall 10:1037
Acknowledgement
This report based upon work supported by the U.S. Department of Energy under Award Number DE-FC36-01ID13981.
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Oryshchyn, D.B., Doğan, Ö.N. An examination of effects of solidification parameters on permeability of a mushy zone in castings. J Mater Sci 43, 1471–1479 (2008). https://doi.org/10.1007/s10853-007-2325-z
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DOI: https://doi.org/10.1007/s10853-007-2325-z