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Mechanical relaxation in supercooled liquids of bulk metallic glasses
Author(s) -
Wen Ping,
Zhao Zuo Feng,
Pan Ming Xiang,
Wang Wei Hua
Publication year - 2010
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201026475
Subject(s) - supercooling , glass transition , materials science , amorphous metal , decoupling (probability) , relaxation (psychology) , microstructure , thermodynamics , condensed matter physics , viscous liquid , composite material , physics , polymer , psychology , social psychology , alloy , control engineering , engineering
We report the mechanical relaxation behaviors in typical supercooled liquids of bulk metallic glasses (BMGs). The metallic supercooled liquids are ideal systems for studying intrinsic motions of glass‐former supercooled liquids because their structure is close to the simple “dense random packing of spheres” model. We show that the primary relaxation in the frequency domain is dissipative and can be described by the empirical Kohlrausch–Williams–Watts function, and the temperature dependence of the primary relaxation time has the Vogel–Fulcher–Tamman form. Beyond the primary relaxation, an excess wing is found on the high‐frequency tail of the primary relaxation. A corresponding shoulder is exhibited at a given frequency in the temperature region below the glass‐transition temperature. The experimental results confirm that the decoupling between the slow β relaxation and the primary ( α ) relaxation exists in metallic supercooled liquids. Based on the current models of the glass transition, we demonstrate that the dynamically heterogeneity originates in the heterogeneous microstructure of metallic supercooled liquids, and a picture of the heterogeneous microstructure is provided.