Critically-percolated, cluster-packed structure in CuZr binary bulk metallic glass demonstrated by molecular dynamics simulations based on plastic crystal model

Akira Takeuchi, Akihisa Inoue

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

Molecular dynamics (MD) simulations based on a plastic crystal model (PCM) were performed for a Cu 0.618Zr 0.382 binary bulk metallic glass (BMG). The local atomic arrangements of the Cu 0.618Zr 0.382 BMG were demonstrated with MD-PCM under an assumption that the BMG is composed of randomly-rotated as well as distorted hypothetical clusters. The Cu-rich Cu 0.618Zr 0.382 alloy was computationally created from a tentatively-created Zr-rich Zr 0.73Cu 0.27 alloy through two steps. The first step includes the Zr 0.73Cu 0.27 alloy quenched from a liquid through conventional MD simulation, whereas the second step has a replacement of the Zr and Cu atoms in the Zr 0.73Cu 0.27 alloy with randomly-rotated icosahedral and tetrahedral clusters, respectively, and subsequent structural relaxation. The Cu 0.618Zr 0.382 alloy, thus created with MD-PCM, was formed in a noncrystalline state as a critically-percolated cluster-packed structure. The analyses with total pair-distribution and interference functions revealed that the calculation results tend to reproduce the experimental data in an as-quenched state. The results explain that the glassforming ability of the Cu 0.618Zr 0.382 BMG is due to (1) a critically-percolated and distorted tetrahedral clusters forming a network and (2) atomistic-level inhomogeneity for the local atomic arrangements with keeping macroscopic homogeneity in terms of the chemical composition and dense random atomic arrangements.

Original languageEnglish
Pages (from-to)1113-1118
Number of pages6
JournalMaterials Transactions
Volume53
Issue number6
DOIs
Publication statusPublished - 2012

Keywords

  • Cluster
  • Copperzirconium alloy
  • Metallic glass
  • Molecular dynamics simulation
  • Percolation

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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