On the evolution of free volume during the deformation of metallic glasses at high homologous temperatures

R. Ekambaram, T Prakash G. Thamburaja, N. Nikabdullah

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Recently a finite-deformation and coupled thermo-mechanically-based theory for metallic glasses has been developed by Thamburaja and Ekambaram [Thamburaja, P., Ekambaram, R., 2007. Coupled thermo-mechanical modelling of bulk-metallic glasses: theory, finite-element simulations and experimental verification. J. Mech. Phys. Solids 55, 1236-1273], and implemented in the ABAQUS/Explicit (2007) finite-element program. In this work, we use the aforementioned constitutive model and its numerical algorithm to study the deformation behavior of a Pd-based metallic glass near its glass transition temperature. At a temperature of 564 K, the material parameters in the constitutive model were fit to the simple tension stress-strain curves and the steady-state free volume concentrations data for a variety of applied strain-rates obtained from De Hey et al. [De Hey, P., Sietsma, J., Van Den Beukel, A., 1998. Structural disordering in a amorphous Pd-Ni-P induced by high temperature deformations. Acta Mater. 46, 5873-5882]. With the model calibrated, the simple tension steady-state stresses and free volume concentrations data for a variety of applied strain-rates at temperatures of 556 K and 549 K (De Hey et al.) were predicted to be in good accord by the constitutive model. Furthermore, the experimental stress-strain curves for samples annealed for different times before the tensile tests were carried out under a particular strain-rate (De Hey et al.) were also well-predicted by the constitutive model. Finally we also perform numerical simulations to show that at a given temperature below the glass transition temperature, metallic glasses which show shear localization behavior as a result of being tested in the fully-annealed condition can be made to deform more homogeneously by first pre-deforming the specimen under high strain-rates at temperatures within the supercooled liquid region before being tested again at temperatures below the glass transition temperature.

Original languageEnglish
Pages (from-to)487-506
Number of pages20
JournalMechanics of Materials
Volume40
Issue number6
DOIs
Publication statusPublished - Jun 2008
Externally publishedYes

Fingerprint

Free volume
Metallic glass
metallic glasses
strain rate
Constitutive models
Strain rate
glass transition temperature
Stress-strain curves
Temperature
temperature
curves
tensile tests
ABAQUS
simulation
shear
liquids
Computer simulation
Liquids
Glass transition temperature

Keywords

  • Constitutive modelling
  • Experimental verification
  • Finite-elements
  • Metallic glass
  • Viscoplasticity

ASJC Scopus subject areas

  • Mechanics of Materials

Cite this

On the evolution of free volume during the deformation of metallic glasses at high homologous temperatures. / Ekambaram, R.; G. Thamburaja, T Prakash; Nikabdullah, N.

In: Mechanics of Materials, Vol. 40, No. 6, 06.2008, p. 487-506.

Research output: Contribution to journalArticle

@article{0214dffd05de41e6a0ee08a92ef9fb96,
title = "On the evolution of free volume during the deformation of metallic glasses at high homologous temperatures",
abstract = "Recently a finite-deformation and coupled thermo-mechanically-based theory for metallic glasses has been developed by Thamburaja and Ekambaram [Thamburaja, P., Ekambaram, R., 2007. Coupled thermo-mechanical modelling of bulk-metallic glasses: theory, finite-element simulations and experimental verification. J. Mech. Phys. Solids 55, 1236-1273], and implemented in the ABAQUS/Explicit (2007) finite-element program. In this work, we use the aforementioned constitutive model and its numerical algorithm to study the deformation behavior of a Pd-based metallic glass near its glass transition temperature. At a temperature of 564 K, the material parameters in the constitutive model were fit to the simple tension stress-strain curves and the steady-state free volume concentrations data for a variety of applied strain-rates obtained from De Hey et al. [De Hey, P., Sietsma, J., Van Den Beukel, A., 1998. Structural disordering in a amorphous Pd-Ni-P induced by high temperature deformations. Acta Mater. 46, 5873-5882]. With the model calibrated, the simple tension steady-state stresses and free volume concentrations data for a variety of applied strain-rates at temperatures of 556 K and 549 K (De Hey et al.) were predicted to be in good accord by the constitutive model. Furthermore, the experimental stress-strain curves for samples annealed for different times before the tensile tests were carried out under a particular strain-rate (De Hey et al.) were also well-predicted by the constitutive model. Finally we also perform numerical simulations to show that at a given temperature below the glass transition temperature, metallic glasses which show shear localization behavior as a result of being tested in the fully-annealed condition can be made to deform more homogeneously by first pre-deforming the specimen under high strain-rates at temperatures within the supercooled liquid region before being tested again at temperatures below the glass transition temperature.",
keywords = "Constitutive modelling, Experimental verification, Finite-elements, Metallic glass, Viscoplasticity",
author = "R. Ekambaram and {G. Thamburaja}, {T Prakash} and N. Nikabdullah",
year = "2008",
month = "6",
doi = "10.1016/j.mechmat.2007.11.005",
language = "English",
volume = "40",
pages = "487--506",
journal = "Mechanics of Materials",
issn = "0167-6636",
publisher = "Elsevier",
number = "6",

}

TY - JOUR

T1 - On the evolution of free volume during the deformation of metallic glasses at high homologous temperatures

AU - Ekambaram, R.

AU - G. Thamburaja, T Prakash

AU - Nikabdullah, N.

PY - 2008/6

Y1 - 2008/6

N2 - Recently a finite-deformation and coupled thermo-mechanically-based theory for metallic glasses has been developed by Thamburaja and Ekambaram [Thamburaja, P., Ekambaram, R., 2007. Coupled thermo-mechanical modelling of bulk-metallic glasses: theory, finite-element simulations and experimental verification. J. Mech. Phys. Solids 55, 1236-1273], and implemented in the ABAQUS/Explicit (2007) finite-element program. In this work, we use the aforementioned constitutive model and its numerical algorithm to study the deformation behavior of a Pd-based metallic glass near its glass transition temperature. At a temperature of 564 K, the material parameters in the constitutive model were fit to the simple tension stress-strain curves and the steady-state free volume concentrations data for a variety of applied strain-rates obtained from De Hey et al. [De Hey, P., Sietsma, J., Van Den Beukel, A., 1998. Structural disordering in a amorphous Pd-Ni-P induced by high temperature deformations. Acta Mater. 46, 5873-5882]. With the model calibrated, the simple tension steady-state stresses and free volume concentrations data for a variety of applied strain-rates at temperatures of 556 K and 549 K (De Hey et al.) were predicted to be in good accord by the constitutive model. Furthermore, the experimental stress-strain curves for samples annealed for different times before the tensile tests were carried out under a particular strain-rate (De Hey et al.) were also well-predicted by the constitutive model. Finally we also perform numerical simulations to show that at a given temperature below the glass transition temperature, metallic glasses which show shear localization behavior as a result of being tested in the fully-annealed condition can be made to deform more homogeneously by first pre-deforming the specimen under high strain-rates at temperatures within the supercooled liquid region before being tested again at temperatures below the glass transition temperature.

AB - Recently a finite-deformation and coupled thermo-mechanically-based theory for metallic glasses has been developed by Thamburaja and Ekambaram [Thamburaja, P., Ekambaram, R., 2007. Coupled thermo-mechanical modelling of bulk-metallic glasses: theory, finite-element simulations and experimental verification. J. Mech. Phys. Solids 55, 1236-1273], and implemented in the ABAQUS/Explicit (2007) finite-element program. In this work, we use the aforementioned constitutive model and its numerical algorithm to study the deformation behavior of a Pd-based metallic glass near its glass transition temperature. At a temperature of 564 K, the material parameters in the constitutive model were fit to the simple tension stress-strain curves and the steady-state free volume concentrations data for a variety of applied strain-rates obtained from De Hey et al. [De Hey, P., Sietsma, J., Van Den Beukel, A., 1998. Structural disordering in a amorphous Pd-Ni-P induced by high temperature deformations. Acta Mater. 46, 5873-5882]. With the model calibrated, the simple tension steady-state stresses and free volume concentrations data for a variety of applied strain-rates at temperatures of 556 K and 549 K (De Hey et al.) were predicted to be in good accord by the constitutive model. Furthermore, the experimental stress-strain curves for samples annealed for different times before the tensile tests were carried out under a particular strain-rate (De Hey et al.) were also well-predicted by the constitutive model. Finally we also perform numerical simulations to show that at a given temperature below the glass transition temperature, metallic glasses which show shear localization behavior as a result of being tested in the fully-annealed condition can be made to deform more homogeneously by first pre-deforming the specimen under high strain-rates at temperatures within the supercooled liquid region before being tested again at temperatures below the glass transition temperature.

KW - Constitutive modelling

KW - Experimental verification

KW - Finite-elements

KW - Metallic glass

KW - Viscoplasticity

UR - http://www.scopus.com/inward/record.url?scp=40049100681&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=40049100681&partnerID=8YFLogxK

U2 - 10.1016/j.mechmat.2007.11.005

DO - 10.1016/j.mechmat.2007.11.005

M3 - Article

AN - SCOPUS:40049100681

VL - 40

SP - 487

EP - 506

JO - Mechanics of Materials

JF - Mechanics of Materials

SN - 0167-6636

IS - 6

ER -