Title: Numerical modelling of microstructure evolution and dendrite growth in alloy solidification process

Authors: Qingyan Xu, Bin Li, Ying Liu, Baicheng Liu

Addresses: Department of Mechanical Engineering, Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084, China. ' Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China. ' Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China. ' Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China

Abstract: A modified cellular automaton method was presented to simulate the evolution of dendrite microstructure accounting for the heterogeneous nucleation, the preferential growth orientation, the solute redistribution both in liquid and solid, the interface curvature and the growth anisotropy during solidification. The effect of the constitutional undercooling and curvature undercooling was incorporated based on the solid/liquid interface equilibrium. The finite difference method coupled with CA model was used to calculate the temperature and solute fields. The free growth of equiaxed grain and competitive growth of columnar grain in the directional solidification was predicted. The effect of the bubble on the dendrite growth and the solute distribution was investigated. The simulated results were compared with those obtained experimentally.

Keywords: modified cellular automaton; microstructure simulation; dendritic grain growth; heterogeneous nucleation; equiaxed grain; columnar grain; numerical modelling; alloy solidification; undercooling; finite difference method.

DOI: 10.1504/IJMPT.2008.019771

International Journal of Materials and Product Technology, 2008 Vol.33 No.1/2, pp.37 - 49

Published online: 30 Jul 2008 *

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