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 language | English |
|---|---|
| Pages (from-to) | 487-506 |
| Number of pages | 20 |
| Journal | Mechanics of Materials |
| Volume | 40 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Jun 2008 |
| Externally published | Yes |
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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 journal › Article
}
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
VL - 40
SP - 487
EP - 506
JO - Mechanics of Materials
JF - Mechanics of Materials
SN - 0167-6636
IS - 6
ER -