TY - JOUR
T1 - Three-dimensional simulations of freckles in binary alloys
AU - Felicelli, S. D.
AU - Heinrich, J. C.
AU - Poirier, D. R.
N1 - Funding Information:
This work was supported by the Advanced Research Project Agency under the Micromodeling Program of the Investment Casting Cooperative Arrangement under contract MDA972-93-2-0001 and by the National Aeronautics and Space Administration, Microgravity Division, under contract NCC8-96. The authors appreciate the collaboration of Dr. A.F. Giamei, from United Technologies Research Center, for the simulations performed at his site. The provision of financial support to S.D. Felicelli by Consejo Nacional de Investigaciones Cientı́ficas y Técnicas (CONICET, Argentina) and by Comisión Nacional de Energı́a Atómica (CNEA, Argentina) is gratefully acknowledged.
PY - 1998/8/1
Y1 - 1998/8/1
N2 - A tridimensional finite-element model was developed to calculate the thermosolutal convection and macrosegregation during the solidification of dendritic alloys. A single set of conservation equations is solved in the mushy zone, all-liquid, and all-solid regions without internal boundary conditions. The model is applied to simulate the directional solidification of a Pb-Sn alloy in cylinders of square and circular cross section. The calculations are started from an all-liquid state and the evolution of convection, solute and energy transport, and the mushy zone growth are followed in time. The results show details of the channels, which result in freckles, that are not observable in existing two-dimensional simulations. Several qualitative features of channels and freckles previously observed in experiments with transparent systems, like chimney convection, preference of channels to be on surfaces, and enhanced solid growth at the channel mouth ("volcanoes") are successfully reproduced.
AB - A tridimensional finite-element model was developed to calculate the thermosolutal convection and macrosegregation during the solidification of dendritic alloys. A single set of conservation equations is solved in the mushy zone, all-liquid, and all-solid regions without internal boundary conditions. The model is applied to simulate the directional solidification of a Pb-Sn alloy in cylinders of square and circular cross section. The calculations are started from an all-liquid state and the evolution of convection, solute and energy transport, and the mushy zone growth are followed in time. The results show details of the channels, which result in freckles, that are not observable in existing two-dimensional simulations. Several qualitative features of channels and freckles previously observed in experiments with transparent systems, like chimney convection, preference of channels to be on surfaces, and enhanced solid growth at the channel mouth ("volcanoes") are successfully reproduced.
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U2 - 10.1016/S0022-0248(98)00357-1
DO - 10.1016/S0022-0248(98)00357-1
M3 - Article
AN - SCOPUS:0032141733
SN - 0022-0248
VL - 191
SP - 879
EP - 888
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
IS - 4
ER -