Analysis of non-equilibrium dendrite growth in a bulk undercooled alloy melt: Model and application
Analysis of non-equilibrium dendrite growth in a bulk undercooled alloy melt: Model and application
复制标题
过冷合金熔体中非平衡枝晶生长分析：模型与应用
DOI：
10.1016/j.actamat.2006.08.042
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发表时间：
2007
期刊：
影响因子：
9.4
通讯作者：
Liu F
中科院分区：
文献类型：
--
作者：
Yang GC;Chen Z;Zhou YH;Wang HF;Liu F
建立了二元合金过冷熔体中稳态枝晶生长模型。作为Galenko和Danilov模型的扩展[Galenko PK， Danilov DA]。Phys Lett A 1997；[235:271]，该模型考虑了非平衡界面动力学，松弛效应，即非平衡液体扩散和弯曲相边界。在当前的边际稳定性分析中，动力学效应起着重要的作用。在相图的热力学计算方面，模型的有效性得到了加强，因为模型预测中使用的拟合参数较少。采用绝对溶质稳定临界速度VC *、最大尖端半径速度vrm和体积液体扩散速度VD三个特征速度，得到了模型预测与过冷Ni-0.7at实验结果的定量一致。% B合金。在中间过冷的速度与过冷阶段有一个平台，即ΔT（VC *）→ΔT(VRm)，这意味着从主要由溶质控制的过程转变为主要由热控制的过程。当枝晶生长速度等于VD时，生长方式由幂律转变为线性，主要由热控生长转变为纯热控生长。
A steady-state dendrite growth model in a bulk undercooled melt was developed for a binary alloy assuming nonlinear liquidus and solidus. As an extension of Galenko and Danilov’s model [Galenko PK, Danilov DA. Phys Lett A 1997;235:271], the present model considered the non-equilibrium interface kinetics, the relaxation effect, i.e. non-equilibrium liquid diffusion and the curved phase boundary. In the current analysis of marginal stability, the kinetic effect played an important role. The model’s validity was reinforced in terms of thermodynamic calculations of the phase diagram, as fewer fitting parameters were used in the model predictions. Adopting three characteristic velocities, i.e. the critical velocity of the absolute solute stability VC∗, the velocity of the maximal tip radius VRmand the velocity of bulk liquid diffusion VD, a quantitative agreement was obtained between the model predictions and the experimental results of an undercooled Ni–0.7at.% B alloy. A plateau observed in the velocity versus undercooling stage, i.e. ΔT(VC∗)→ΔT(VRm), for intermediate undercoolings implied a transition from a mainly solute-controlled to a mainly thermal-controlled process. If the dendrite growth velocity equaled VD, an abrupt change of growth mode from the power law to linear growth proceeded, which could be ascribed to a transition from mainly thermal-controlled growth to purely thermal-controlled growth.
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DOI：
10.1016/0001-6160(86)90112-4
发表时间：
1986-08
期刊：
Acta Metallurgica
影响因子：
--
作者：
R. Trivedi;W. Kurz
通讯作者：
R. Trivedi;W. Kurz
影响因子：
1.8
作者：
P. Galenko;D. Danilov
通讯作者：
P. Galenko;D. Danilov
DOI：
10.1016/0001-6160(87)90174-x
发表时间：
1987-04-01
期刊：
ACTA METALLURGICA
影响因子：
--
作者：
LIPTON, J;KURZ, W;TRIVEDI, R
通讯作者：
TRIVEDI, R
DOI：
10.1016/0001-6160(88)90333-1
发表时间：
1988-08-01
期刊：
ACTA METALLURGICA
影响因子：
--
作者：
AZIZ, MJ;KAPLAN, T
通讯作者：
KAPLAN, T
影响因子：
3.7
作者：
P. Galenko
通讯作者：
P. Galenko