Structural disordering in amorphous Pd40Ni40P20 induced by high temperature deformation

Hey, Paul de; Sietsma, Jilt; Beukel, A. van den

doi:10.1016/s1359-6454(98)00234-1

Cited by 248 publications

(153 citation statements)

References 18 publications

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“…Interestingly, for both strain rates the atomic volume increases within the flow-softening regime of the stress-strain curves, suggesting perhaps that the stress drop is associated with an increase in free volume throughout the atomic structure. 13 Furthermore, the magnitude of the increase in atomic volume following yielding increases with increasing strain rate, which is consistent with experimental observations for homogeneously deformed multicomponent glasses. 13,33 For the two different strain rates, both the atomic volume and the stress approach plateau values for applied strains above ϳ0.06.…”

Section: B High-temperature Deformation Behavior Of Amorphous Cu 64supporting

confidence: 89%

“…13 Furthermore, the magnitude of the increase in atomic volume following yielding increases with increasing strain rate, which is consistent with experimental observations for homogeneously deformed multicomponent glasses. 13,33 For the two different strain rates, both the atomic volume and the stress approach plateau values for applied strains above ϳ0.06. As discussed before, this plateau regime has been attributed to a dynamic equilibrium between the creation and annihilation of free volume.…”

Section: B High-temperature Deformation Behavior Of Amorphous Cu 64supporting

confidence: 89%

“…For example, van den Beukel et al 11 showed that structural relaxation, which they correlated with a reduction in free volume, significantly increased viscosity and stiffness. Alternatively, free volume has been shown to increase during high-temperature deformation, 12,13 allowing the system to recover ductility that is diminished following low temperature annealing. The atomistic mechanisms associated with free volume changes in metallic glasses are difficult to study experimentally.…”

Section: Introductionmentioning

confidence: 99%

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Deformation behavior of an amorphous Cu64.5Zr35.5 alloy: A combined computer simulation and experimental study

Mendelev

Ott

Heggen

et al. 2008

Journal of Applied Physics

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Molecular dynamics ͑MD͒ simulations were performed to examine the temperature-dependent elastic properties and high-temperature deformation behavior of a Cu 64.5 Zr 35.5 amorphous alloy. From the simulations we find that the elastic constants of the amorphous solid and supercooled liquid exhibit an approximately linear temperature dependence. The predicted temperature dependence of the Young's modulus for the amorphous solid obtained from the MD simulations is in good agreement with experimental measurements using dynamic mechanical analysis. Furthermore, the high-temperature plastic deformation behavior determined by MD simulations is qualitatively in good agreement with results from plastic deformation experiments performed on 1 mm diameter Cu 64.5 Zr 35.5 metallic glass rods at 698 K. Notably, the MD simulations reveal that the flow softening regime of the stress-strain curve corresponds to an increase in the free volume in the atomic structure. Moreover, the simulations indicate that the atomic mobility significantly increases within the same regime.

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Section: B High-temperature Deformation Behavior Of Amorphous Cu 64supporting

confidence: 89%

Section: B High-temperature Deformation Behavior Of Amorphous Cu 64supporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Deformation behavior of an amorphous Cu64.5Zr35.5 alloy: A combined computer simulation and experimental study

Mendelev

Ott

Heggen

et al. 2008

Journal of Applied Physics

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“…[5][6][7] Furthermore, the effect of strain rate on viscosity induced by mechanical deformation has also been linked to changes in configurational enthalpy. 8 However, attributing the deformationally induced softening of liquids to a unique functional relation between shear modulus and stored configurational enthalpy is a concept that has just recently been brought to attention. 3 This concept essentially suggests that conversion of mechanical work into stored configurational enthalpy induces softening via a dependence of shear modulus on configurational enthalpy.…”

mentioning

confidence: 99%

Deformation of glass forming metallic liquids: Configurational changes and their relation to elastic softening

Harmon¹,

Demetriou²,

Johnson³

et al. 2007

Applied Physics Letters

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The change in the configurational enthalpy of metallic glass forming liquids induced by mechanical deformation and its effect on elastic softening is assessed. The acoustically measured shear modulus is found to decrease with increasing configurational enthalpy by a dependence similar to one obtained by softening via thermal annealing. This establishes that elastic softening is governed by a unique functional relationship between shear modulus and configurational enthalpy. © 2007 American Institute of Physics. ͓DOI: 10.1063/1.2717017͔In the recent work of Johnson and co-workers, 1-4 a link between elastic softening and configurational changes in metallic glass forming liquids has been proposed. The steepness of the viscosity dependence on temperature in the vicinity of the glass transition, i.e., the liquid fragility, has been known to be associated with the stored configurational enthalpy since the early work of Angell and co-workers. [5][6][7] Furthermore, the effect of strain rate on viscosity induced by mechanical deformation has also been linked to changes in configurational enthalpy. 8 However, attributing the deformationally induced softening of liquids to a unique functional relation between shear modulus and stored configurational enthalpy is a concept that has just recently been brought to attention. 3 This concept essentially suggests that conversion of mechanical work into stored configurational enthalpy induces softening via a dependence of shear modulus on configurational enthalpy. The thermodynamic state variable controlling flow in this concept is identified to be the isoconfigurational shear modulus. Experimental validation of earlier concepts based on the "free volume" hypothesis 9 has not been possible, mainly due to the lack of a fundamental thermodynamic definition of free volume. In contrast, the isoconfigurational shear modulus is a thermodynamically well-defined and experimentally accessible property, rendering this concept experimentally verifiable. In the present study, the change in configurational enthalpy induced by mechanical work and its effect on the softening of metallic glass forming liquids is evaluated by means of compressive experiments, ultrasonic measurements, and enthalpy recovery tests.For the loading experiments we utilized cylindrical specimens of Pt 57.2 Ni 5.3 Cu 14.7 P 22.5 ͑Refs. 10 and 11͒ and Pd 43 Ni 10 Cu 27 P 20 , 3,12 which we deformed isothermally at constant strain rates. The loading setup described in Ref. 13 is utilized. Deformation was performed for a period of time sufficient to allow a steady flow stress state in the nonNewtonian regime to be attained. Upon unloading, the specimens were quenched as rapidly as possible to capture the configurational state associated with that flow stress.We assessed the elastic softening induced by mechanical deformation by evaluating the isoconfigurational shear modulus at the high-frequency "solidlike" limit G. We evaluated G of the quenched unloaded specimens ultrasonically, 14 and extrapolated the room temperature m...

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“…The free volume model provides a simple and practical model to describe the plasticity of amorphous alloys. The applicability of the model has been well verified and it can qualitatively explain many mechanics properties of amorphous alloys [74][75][76] . In 1979, Argon 77 used "shear transformation" to explain the plastic deformation of metallic glasses and the theory meets well with the experimental observations.…”

Section: Free Volume Modelmentioning

confidence: 80%

The Development of Structure Model in Metallic Glasses

et al. 2017

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Metallic glasses (amorphous alloys) have grown from a singular observation to an expansive class of alloys with a broad range of scientific interests. Their unique properties require a robust understanding on the structures at the atomic level while alloys in this class have a similar outlook on the microstructure. In this review, we went through the history of the majority studies on the structure models of metallic glasses, and summarized their historical contributions to the understanding of the structure metallic glasses and the relationship between their structures and properties.

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Structural disordering in amorphous Pd40Ni40P20 induced by high temperature deformation

Cited by 248 publications

References 18 publications

Deformation behavior of an amorphous Cu64.5Zr35.5 alloy: A combined computer simulation and experimental study

Deformation behavior of an amorphous Cu64.5Zr35.5 alloy: A combined computer simulation and experimental study

Deformation of glass forming metallic liquids: Configurational changes and their relation to elastic softening

The Development of Structure Model in Metallic Glasses

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