Numerical modeling of solidification morphologies and segregation patterns in cast dendritic alloys
Numerical modeling of solidification morphologies and segregation patterns in cast dendritic alloys
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DOI：
10.1016/s1359-6454(99)00325-0
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发表时间：
1999-11-26
期刊：
影响因子：
9.4
通讯作者：
Nastac, L
中科院分区：
文献类型：
--
作者：
Nastac, L
建立了一个模拟二元合金凝固过程中枝晶演化的随机模型。该模型包括温度分布，溶质在液相和固相中的再分配，曲率和生长各向异性的时间相关的计算，而无需进一步假设的成核和生长的树枝状晶体。随机程序precedently开发的纳瓦尔尼和Stefanescu（Modell。你好mater. sci. Engng，1997，5（4），391）来控制枝晶的形核和生长。基于欧拉-拉格朗日方法，提出了一种在固定笛卡尔网格上精确跟踪尖锐固/液界面的数值算法。二维介观计算（即在枝晶尖端长度尺度）进行模拟柱状和等轴枝晶形态的演变，包括柱状等轴过渡的形成。详细分析了溶质过冷度和曲率过冷度对二元合金凝固过程中枝晶形貌和偏析形态演变的影响。(C)1999《冶金学报》由爱思唯尔科技有限公司出版。保留所有权利。
A comprehensive stochastic model for simulating the evolution of dendritic crystals during the solidification of binary alloys was developed. The model includes time-dependent calculations for temperature distribution, solute redistribution in the liquid and solid phases, curvature, and growth anisotropy without further assumptions on the nucleation and growth of dendritic crystals. Stochastic procedures preciously developed by Nastac and Stefanescu (Modell. Simul. Mater. Sci. Engng, 1997, 5(4), 391) for simulating dendritic grains were used to control the nucleation and growth of dendrites. A numerical algorithm based on an Eulerian-Lagrangian approach was developed to explicitly track the sharp solid/liquid (S/L) interface on a fixed Cartesian grid. Two-dimensional mesoscopic calculations (i.e. at the dendrite tip length scale) were performed to simulate the evolution of columnar and equiaxed dendritic morphologies including the formation of the columnar-to-equiaxed transition. The effects of solutal and curvature undercoolings on the evolution of both the dendrite morphology and segregation patterns during the solidification of binary alloys were analyzed in detail. (C) 1999 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.