Formation and evolution of nano-clusters in a large-scale system of Cu- Zr alloy during rapid solidification process

YF Mo and RS Liu and YC Liang and HT Zhang and ZA Tian and ZY Hou and HR Liu and LL Zhou and P Peng and TH Gao, COMPUTATIONAL MATERIALS SCIENCE, 98, 1-9 (2015).

DOI: 10.1016/j.commatsci.2014.10.031

To investigate the formation and evolution mechanisms of nano-clusters formed during the rapid solidification process, a molecular dynamics (MD) simulation study has been performed for a system consisting of 106 atoms of Cu64.5Zr35.5 alloy. Adopting a new cluster-type index method (CTIM-3) to analyse the local atomic clusters, it is found that the dominant microstructural configurations in the supercooled liquid and amorphous are the icosahedrons and their combinations, especially the intercross-sharing (IS) clusters linked of two icosahedrons (IS-ICO- clusters) can be used to build some larger IS-ICO nano-clusters with different sizes. Highly interesting, in the system the number of atoms in various IS-ICO nano-clusters demonstrates a magic number sequence of 19, 23, 25, 27, 29, 31, 33, 35, 37, 41, 43, and so on. The magic number clusters can be classified into three main types: chain-like, triangle- tailed and quadrilateral-tailed. The degree of tightness for IS-ICO nano-cluster can be expressed by formula n(I)/n(IS). And some IS-ICO nano-structures have stronger mechanical stability and can bear higher load. (C) 2014 Published by Elsevier B.V.

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