COUPLED THERMO- MECHANICAL ANALYSIS OF SHEAR LOCALIZATION IN BULK METALLIC GLASSES

Document Type : Original Article

Authors

1 Graduate student, Department of Mechanical Engineering, National University of Singapore, Singapore.

2 Assistant professor, Department of Mechanical Engineering, National University of Singapore, Singapore.

3 Professor, Department of Mechanical Engineering, Universiti kembangsaan Malaysia, Malaysia.

Abstract

ABSTRACT
A Coupled-thermo-mechanical, finite deformation based constitutive model to describe
the deformation behavior of bulk metallic glasses was recently developed by
Thamburaja and Ekambaram [1] and implemented in ABAQUS/Explicit (2007) finiteelement
program by writing a user material sub-routine. In this work, the effectiveness
of this temperature-displacement model, particularly while simulating the localizing
behavior of metallic glasses which are deformed within the super-cooled liquid region is
comprehensively analyzed.
Numerical simulations were performed using the set of constitutive equations and list of
material parameters from Thamburaja and Ekambaram [1] for Vitreloy-1 metallic glass.
Coupled-temperature-displacement simulations were performed under specified
deformation rates to study the shear localization phenomena for temperatures around
and above the glass transition temperature. These deformation rates were obtained
from the experimentally determined localization mapping from Lu, J. et. al. [2] for
Vitreloy-1. The results from our finite element simulations could distinctively delineate
the incidence of shear bands for strain rates well within the experimentally obtained
range for localization, for ambient temperatures near the glass transition region.

Keywords