中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 22 No. 2 February 2012 |
phase field method quantitatively
(1. State Key Laboratory of Gansu Advanced Nonferrous Metal Materials,
Lanzhou University of Technology, Lanzhou 730050, China;
2. Research Center of Gansu Nonferrous Metal Materials and Composite Materials Engineering,
Lanzhou 730050, China;
3. CAD Center, Lanzhou University of Technology, Lanzhou 730050, China)
Abstract:The influence of supercooled melt forced lamina flow on microsegregation was investigated. The concentration distribution at solid−liquid boundary of binary alloy Ni−Cu was simulated using phase field model coupled with flow field. The microsegregation, concentration maximum value, boundary thickness of concentration near upstream dendrite and normal to flow dendrite, and downstream dendrite were studied quantitatively in the case of forced lamia flow. The simulation results show that solute field and flow field interact complexly. Compared with melt without flow, in front of upstream dendrite tip, the concentration boundary thickness is the lowest and the concentration maximum value is the smallest for melt with flow. However, in front of downstream dendrite tip, the results are just the opposite. The zone of poor Cu in upstream dendrite where is the most severely microsegregation and shrinkage cavity is wider and the concentration is lower for melt with flow than that without flow.
Key words: computer simulation; phase field method; solidification; forced lamina flow; microsegregation; solute redistribution; shrinkage cavity