On the role of confinement on solidification in pure materials and binary alloys
On the role of confinement on solidification in pure materials and binary alloys
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DOI：
10.1080/14786430500157060
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发表时间：
2006-06
影响因子：
1.6
通讯作者：
B. Athreya;J. Dantzig;S. Liu;R. Trivedi
中科院分区：
文献类型：
--
作者：
B. Athreya;J. Dantzig;S. Liu;R. Trivedi
我们使用相场模型来研究约束对枝晶生长的影响，在过冷熔体中凝固的纯材料中，以及在稀二元合金的定向凝固中。具体而言，我们通过量化作为δ和其他工艺参数的函数的枝晶尖端速度和曲率来观察改变垂直域范围（δ）对尖端选择的影响。随着δ的减小，我们发现枝晶尖端的工作状态受到有限边界存在的显著影响。对于特定的边界条件，我们观察到在非常小的δ下，纯材料和合金的生长状态从3D到2D的切换。我们表明，从合金模型的结果相比，从实验研究调查这种效果。
We use a phase-field model to study the effect of confinement on dendritic growth, in a pure material solidifying in an undercooled melt, and in the directional solidification of a dilute binary alloy. Specifically, we observe the effect of varying the vertical domain extent (δ) on tip selection, by quantifying the dendrite tip velocity and curvature as a function of δ, and other process parameters. As δ decreases, we find that the operating state of the dendrite tips becomes significantly affected by the presence of finite boundaries. For particular boundary conditions, we observe a switching of the growth state from 3D to 2D at very small δ, in both the pure material and alloy. We demonstrate that results from the alloy model compare favorably with those from an experimental study investigating this effect.