Large-scale phase-field simulations of ternary eutectic microstructure evolution
Large-scale phase-field simulations of ternary eutectic microstructure evolution
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DOI：
10.1016/j.commatsci.2016.02.001
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发表时间：
2016-05
影响因子：
3.3
通讯作者：
P. Steinmetz;J. Hötzer;M. Kellner;A. Dennstedt;B. Nestler
中科院分区：
文献类型：
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作者：
P. Steinmetz;J. Hötzer;M. Kellner;A. Dennstedt;B. Nestler
三元共晶合金的微观结构演变是当前多元合金研究的主题，因为其图案种类繁多且性能可调。在实验中，通常会观察到不同排列图案之间的接触区域。然而，它们的形成及其对微观结构演变的影响尚未得到研究。为了研究 3D 图案和集成接触区域，对理想系统进行了大规模相场模拟，从而实现了杆形状的量化。首先，通过 Jackson-Hunt 方法对具有最小过冷 λ JH 的层状间距进行数值确定。然后，系统地改变域大小和初始填充，以分析这两个量对图案形成的影响，并确定统计体积元素（SVE）所需的计算域大小。统计测量表明最小尺寸为 400×400 体素单元，相当于 4.3 λ JH×4.3 λ JH，与凝固前沿平行，并且需要大规模模拟来解决 SVE。除了六边形结构之外，还发现了不同的稳定图案，具体取决于这些图案的域尺寸、初始填充和过冷度。在大规模模拟中，可以观察到接触区的形成和演变，并通过实验报告。
The microstructure evolution of ternary eutectic alloys is subject of current research for multicomponent alloys, due to the large variety of patterns and their widely adjustable properties. In experiments, contact zones between the different aligned patterns are commonly observed. However, their formation and influence on the microstructure evolution was not yet investigated. To study 3D patterns and the integrated contact zones, large-scale phase-field simulations of an idealized system are conducted, enabling the quantification of the rod shapes. First, the lamellar spacing with the minimum undercooling λ JH from the Jackson–Hunt approach is numerically determined. Then, the domain size and initial filling are systematically varied, to analyze the influence of these two quantities on the pattern formation and to determine the required computational domain size for statistical volume elements (SVE). The statistical measures indicate a minimum size of 400× 400 voxel cells, equivalent to 4.3 λ JH× 4.3 λ JH, parallel to the solidification front and the necessity of large scale simulations to resolve SVEs. Different stable patterns, beside the hexagonal structures, are found, depending on the domain size, the initial filling and the undercooling of these patterns. In large-scale simulations, the formation and evolution of contact zones is observed, which are reported from experiments.