Mushy zone modeling with microstructural coarsening kinetics
Mushy zone modeling with microstructural coarsening kinetics
复制标题
DOI：
10.1007/bf02801183
复制
发表时间：
1992-02
期刊：
影响因子：
--
通讯作者：
M. Glicksman;Richard N. Smith;S. P. Marsh;R. Kuklinski
中科院分区：
文献类型：
--
作者：
M. Glicksman;Richard N. Smith;S. P. Marsh;R. Kuklinski
糊状区模拟的一个关键要素是描述糊状区内长度尺度的微观演化和宏观输运过程的影响。本文描述了绝热糊状区中相粗化的平均场统计理论的一些最新进展。主要的理论结果是：(1)时间标度律，表明平均长度尺度随着时间的1/3增加；(2)基于球形固体颗粒形状的糊状区长度尺度的自相似分布；(3)提供粗化过程与材料参数和固相体积分数的依赖关系的动力学速率常数。描述了高精度的热衰变实验，这些实验在绝热条件下的纯材料糊状区验证了理论的某些方面。然后将微观粗化理论集成到一个简单的一维合金凝固宏观传热模型中。该方法能够预测宏观传热对Al-Cu合金中一次和二次枝晶间距演变的影响。
A key element of mushy zone modeling is the description of the microscopic evolution of the lengthscales within the mushy zone and the influence of macroscopic transport processes. This article describes some recent progress in developing a mean-field statistical theory of phase coarsening in adiabatic mushy zones. The main theoretical results are (1) temporal scaling laws that indicate that the average lengthscale increases as time1/3, (2) a self-similar distribution of mushy zone lengthscales based on spherical solid particle shapes, and (3) kinetic rate constants which provide the dependences of the coarsening process on material parameters and the volume fraction of the solid phase. High precision thermal decay experiments are described which verify aspects of the theory in pure material mushy zones held under adiabatic conditions. The microscopic coarsening theory is then integrated within a simple macroscopic heat-transfer model of one-dimensional alloy solidification. The method demonstrates an ability to predict the influence of macroscopic heat transfer on the evolution of primary and secondary dendrite arm spacings in Al-Cu alloys.