Atomic structure and thermal stability of interfaces between metallic glass and embedding nano-crystallites revealed by molecular dynamics simulations

XZ Gao and GQ Yang and B Xu and C Qi and LT Kong and JF Li, JOURNAL OF ALLOYS AND COMPOUNDS, 647, 331-337 (2015).

DOI: 10.1016/j.jallcom.2015.06.150

Molecular dynamics simulations were performed to investigate the atomic structure and thermal stability of interfaces formed between amorphous Cu50Zr50 matrix and embedding B2 CuZr nano-crystallites. The interfaces are found to be rather abrupt, and their widths show negligible dependence on the nano-crystallite size. Local atomic configuration in the interfacial region is dominated by geometry characterized by Voronoi polyhedra < 0,5,2,6 > and < 0,4,4,6 >, and the contents of these polyhedra also exhibit apparent size dependence, which in turn results in an increasing trend in the interfacial energy against the nano- crystallite size. Annealing of the interface models at elevated temperatures will also enrich these characterizing polyhedra. While when the temperature is as high as the glass transition temperature of the matrix, growth of the nano-crystallites will be appreciable. The growth activation energy also shows size dependence, which is lower for larger nano-crystallites, suggesting that large nano-crystallites are prone to grow upon thermal disturbance. (C) 2015 Elsevier B.V. All rights reserved.

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