The molecular dynamic simulations have been performed to study the atomic clusters evolution during various cooling processes of Cu-50%Ni alloy (atomic fraction). The basic structure unit of Cu-50%Ni glass formed at the cooling rate Of 1x 10(14) K/s and the arrangement of Cu and Ni atoms in these structures are investigated. The results indicate that the glass formed at higher cooling rate has higher energy and higher glass transition temperature (T-g). The short-range interaction between atoms becomes stronger and stronger in the cooling process. 1551 bonded pair plays an important role in the glass system and is sensitive to cooling rates. Not only icosahedra but also various defective polyhedra are found in the glass. In these defective polyhedra, those composed with more 1551 bonded pairs have a larger number. There are few Frank-Kasper and Bernal polyhedra in the alloy. Generally Cu atoms tend to locate at the vertexes while Ni atoms prefer to occupy the interspaces at the center of the polyhedra. The total number of the polyhedra decreases with the decrease of the cooling rate.
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