Liquid ordering induced heterogeneities in homogeneous nucleation during solidification of pure metals
Liquid ordering induced heterogeneities in homogeneous nucleation during solidification of pure metals
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DOI：
10.1016/j.jmst.2021.08.008
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发表时间：
2022
影响因子：
10.9
通讯作者：
A. Mahata;T. Mukhopadhyay;M. Asle Zaeem
中科院分区：
文献类型：
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作者：
A. Mahata;T. Mukhopadhyay;M. Asle Zaeem
均匀晶体成核容易形成缺陷，并且经常经历非均匀性，其推论在加工晶体材料和控制其物理性质中是至关重要的。在文献中，相关的不均匀性是否是均质成核的组成部分一直存在争议。在这项研究中，通过整合的概率方法与大规模的分子动力学模拟的基础上，最先进的高温原子间相互作用势，我们试图解决的来源和机制的不确定性，在纯熔体凝固过程中均匀成核。为此目的，研究了不同类型的结构金属，包括面心立方铝，体心立方铁和六方密堆积镁。结果表明，无论元素类型或固化的晶体结构，液态金属的致密化过程伴随着形成晶体之前原子的短程有序化，控制均匀成核过程中的非均匀性。
Homogeneous crystal nucleation is prone to formation of defects and often experiences heterogeneities, the inferences of which are crucial in processing crystalline materials and controlling their physical properties. It has been debated in literature whether the associated heterogeneities are an integral part of the homogenous nucleation. In this study by integrating a probabilistic approach with large-scale molecular dynamics simulations based on the most advanced high-temperature interatomic potentials, we attempt to address the ambiguity over the sources and mechanisms of heterogeneities in homogenous nucleation during solidification of pure melts. Different classes of structured metals are investigated for this purpose, including face-centered cubic aluminum, body-centered cubic iron, and hexagonal close-packed magnesium. The results reveal, regardless of the element type or the solidified crystal structure, that the densification process of liquid metals is accompanied by short-range orderings of atoms prior to the formation of crystals, controlling the heterogeneities during homogenous nucleation.