A continuum mixture model of the direct chill casting process is compared to experimental results from industrial scale aluminum billets. The model, which includes the transport of free-floating solid particles, can simulate the effect of a grain refiner on macrosegregation and fluid flow. It is applied to an Al-6 wt% Cu alloy and the effect of grain refiner on macrosegregation, sump profile, and temperature fields are presented. Two 45 cm diameter billets were cast under production conditions with and without grain refiner. Temperature and composition measurements and sump profiles are compared to the numerical results. The comparison shows some agreement for the grain refined case. It is believed that an incorrect assumption about the actual grain structure prevents good agreement in the non-grain refined billet.

1.
Finn, T. L., Chu, M. G., and Bennon, W. D., 1992, “The Influence of Mushy Region Microstructure on Macrosegregation in Direct Chill Cast Aluminum-Copper Round Ingots,” in Micro/Macro Scale Phenomena in Solidification, ASME HTD-Vol. 218, C. Beckermann, et al., eds., ASME, New York, pp. 17–26.
2.
Yu, H., and Granger, D. A., 1986, “Macrosegregation in Aluminum Alloy Ingot Cast by the Semicontinuous Direct Chill (DC) Method,” in Aluminum Alloys-Their Physical and Mechanical Properties, EMAS, United Kingdom, pp. 17–29.
3.
Chu, M. G., and Jacoby, J. E., 1990, “Macrosegregation Characteristics of Commercial Size Aluminum Alloy Ingot Cast by the Direct Chill Method,” in Light Metals 1990, C. M. Bickert, ed., TMS, pp. 925–930.
4.
Dorward, R. C., and Beerntsen, D. J., 1990, “Effects of Casting Practice on Macrosegregation and Microstructure of 2024 Alloy Billet,” in Light Metals 1990, C. M. Bickert, ed., TMS, pp. 919–924.
5.
Gariepy, B., and Caron, Y., 1991, “Investigation in the Effects of Casting Parameters on the Extent of Centerline Macrosegregation in DC Cast Sheet Ingots,” in Light Metals 1991, E. L. Rooy, ed., TMS, pp. 961–971.
6.
Flood, S. C., Katgerman, L., and Voller, V. R., 1991, “The Calculation of Macrosegregation and Heat and Fluid Flows in the D.C. Casting of Aluminum Alloys,” in Modeling of Casting, Welding and Advanced Solidification Processes V, M. Rappaz, et al., eds., TMS, pp. 683–690.
7.
Reddy, A. V., and Beckermann, C., 1995, “Simulation of the Effects of Thermosolutal Convection, Shrinkage Induced Flow, and Solid Transport on Macrosegregation and Equiaxed Grain Size Distribution in a DC Continuous Cast Al-Cu Round Ingot,” in Materials Processing in the Computer Age II, V. R. Voller, et al., eds., pp. 89–102.
8.
Ni
,
J.
, and
Beckermann
,
C.
,
1991
, “
A Volume-Averaged Two-Phase Model for Transport Phenomena During Solidification
,”
Metall. Mater. Trans. B
,
22B
, pp.
349
361
.
9.
Reddy
,
A. V.
, and
Beckermann
,
C.
,
1997
, “
Modeling of Macrosegregation Due to Thermosolutal Convection and Contraction-Driven Flow in Direct Chill Continuous Casting of an Al-Cu Round Ingot
,”
Metall. Mater. Trans. B
,
28B
, pp.
479
489
.
10.
Vreeman
,
C. J.
,
Krane
,
M. J. M.
, and
Incropera
,
F. P.
,
2000
, “
The Effect of Free-Floating Dendrites and Convection on Macrosegregation in Direct Chill Cast Aluminum Alloys—I: Model Development
,”
Int. J. Heat Mass Transf.
,
43
, pp.
677
686
.
11.
Vreeman
,
C. J.
, and
Incropera
,
F. P.
,
2000
, “
The Effect of Free-Floating Dendrites and Convection on Macrosegregation in Direct Chill Cast Aluminum Alloys—II: Predictions for Al-Cu and Al-Mg alloys
,”
Int. J. Heat Mass Transf.
,
43
, pp.
687
704
.
12.
Bennon
,
W. D.
, and
Incropera
,
F. P.
,
1987
, “
A Continuum Model for Momentum, Heat and Species Transport in Binary Solid-Liquid Phase Change Systems—I: Model Formulation
,”
Int. J. Heat Mass Transf.
,
30
, pp.
2161
2170
.
13.
Ni
,
J.
, and
Incropera
,
F. P.
,
1995
, “
Extension of the Continuum Model for Transport Phenomena Occurring During Metal Alloy Solidification—I: The Conservation Equations
,”
Int. J. Heat Mass Transf.
,
38
, pp.
1271
1284
.
14.
Prescott
,
P. J.
,
Incropera
,
F. P.
, and
Bennon
,
W. D.
,
1991
, “
Modeling of Dendritic Solidification Systems: Reassessment of the Continuum Momentum Equation
,”
Int. J. Heat Mass Transf.
,
34
, pp.
2351
2358
.
15.
Wang
,
C. Y.
, and
Beckermann
,
C.
,
1996
, “
Equiaxed Dendritic Solidification With Convection: Part I. Multiscale/Multiphase Modeling
,”
Metall. Mater. Trans. A
,
27A
, pp.
2754
2764
.
16.
Wang
,
C. Y.
, and
Beckermann
,
C.
,
1996
, “
Equiaxed Dendritic Solidification With Convection: Part II. Numerical Simulations for an Al-4 wt pct Cu alloy
,”
Metall. Mater. Trans. A
,
27A
, pp.
2765
2783
.
17.
Beckermann
,
C.
, and
Wang
,
C. Y.
,
1996
, “
Equiaxed Dendritic Solidification With Convection: Part III. Comparisons With NH4Cl-H2O Experiments
,”
Metall. Mater. Trans. A
,
27A
, pp.
2784
2795
.
18.
Ocansey, P., Bhat, M. S., and Poirier, D. R., 1994, “Permeability for Liquid Flow in the Mushy Zones of Equiaxed Castings,” in Light Metals 1994, U. Mannweiler, ed., TMS, pp. 807–812.
19.
Smithell’s Metals Reference Handbook, 1992, 7th ed., E. A. Barnes and G. B. Brook, eds., Butterworth-Heinemann, Ltd., Oxford, pp. 14.1–14.14.
20.
Bennon
,
W. D.
, and
Incropera
,
F. P.
,
1988
, “
Numerical Analysis of Binary Solid-Liquid Phase Change Using a Continuum Model
,”
Numer. Heat Transfer
,
13
, pp.
277
296
.
21.
Patankar, S., 1980, Numerical Heat Transfer and Fluid Flow, Hemisphere, New York, pp. 113–134.
22.
Vreeman
,
C. J.
, and
Incropera
,
F. P.
,
1999
, “
Numerical Discretization of Species Equation Source Terms in Binary Mixture Models of Solidification and Their Impact on Macrosegregation in Semi-Continuous, Direct Chill Casting Systems
,”
Numer. Heat Transfer, Part B
,
36
(
1
), pp.
1
14
.
23.
Vreeman, C. J., 1997, “Modeling Macrosegregation in Direct Chill Cast Aluminum Alloys,” M.S. thesis, School of Mechanical Engineering, Purdue University, West Lafayette, IN.
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