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Indexed by:期刊论文

Date of Publication:2011-09-01

Journal:ACTA MATERIALIA

Included Journals:Scopus、SCIE、EI

Volume:59

Issue:15

Page Number:5917-5923

ISSN No.:1359-6454

Key Words:Metallic glasses; Cluster-plus-glue-atom model; Electron concentration; Hume-Rothery phase

Abstract:The electrons per atom ratio eta is an important factor in discussing the stabilization mechanism of metallic glasses. However, the eta assignment is complicated by hybridization effects, particular in transition metal systems. We have previously proposed the "cluster-plus-glue-atom" model for metallic glasses and the relevant cluster formula [cluster](glue atom)(x), x similar to, 1 or 3. In the present paper, this model is combined with Haussler's global-resonance model into a so-called cluster-resonance model. This model allows the calculation of the Fermi vector and hence the effective eta of an ideal metallic glass. By assuming an ideal dense packing of the clusters, the atomic density can be obtained and eta becomes associated with the number of atoms in the unit cluster formula Z. Experiments are carried out to verify these correlations. Alloys like Cu8Zr5Al, Ni4Zr9Al2 and [Ni7Nb5Zr]Ni-3, possessing locally the highest glass-forming abilities, are interpreted by cluster formulae, with their Zs being determined by their c/a values. Such verifications not only validate the proposed eta calculation schemes and the models behind them, but also support the ideal metallic glass feature of bulk metallic glasses with high glass-forming abilities. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.