论文标题
Al-Ni合金中的晶体成核：一种无监督的化学和拓扑学习方法
Crystal Nucleation in Al-Ni Alloys: an Unsupervised Chemical and Topological Learning Approach
论文作者
论文摘要
结晶代表了一个基本过程，该过程构成材料的固化并确定其微观结构。在原子量表上复杂现象的驱动下，其对合金的理解仍然难以捉摸。目前的工作提出了一项大规模的分子动力学模拟研究，该研究对原型底层过冷的Al-Ni二元合金的均匀晶体成核途径。无监督的拓扑学习分析表明，成核首先是从化学订购中设置的，然后是基础晶相的键取向排序。我们的结果还表明，取决于组成的不同多晶型物选择。尽管AL50 Ni50的成核途径在B2短距离出现的情况下显示出一个步骤，但对于AL25 NI75，可以看到朝向L12相的逐步成核。进一步讨论了纯Al和Ni对应物的成核的影响。
Crystallization represents a fundamental process engendering solidification of a material and determines its microstructure. Driven by complex phenomena at the atomic scale, its understanding for alloys still remains elusive. The present work proposes a large scale molecular dynamics simulation study of the homogeneous crystal nucleation pathways of prototypical undercooled Al-Ni binary alloys. An unsupervised topological learning analysis shows that the nucleation sets in first from a chemical ordering, followed by a bond-orientational ordering of the underlying crystal phase. Our results indicate also a different polymorph selection that depends on composition. While the nucleation pathway of Al50 Ni50 displays a single step with the emergence of B2 short-range order, a step-wise nucleation toward the L12 phase is seen for Al25 Ni75 . The influence of the nucleation of pure Al and Ni counterparts is further discussed.
