Atomic-level structure and structure–property relationship in metallic glasses

Cheng, Yongqiang; Ma, Evan

doi:10.1016/j.pmatsci.2010.12.002

Cited by 1,509 publications

(1,023 citation statements)

References 472 publications

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“…While a comprehensive review is outside the scope of this paper, Cheng and Ma [37] published a thorough review of metallic glass research in 2011.…”

Section: Glasses and The Glass Transitionmentioning

confidence: 99%

Thermodynamic modelling of liquids: CALPHAD approaches and contributions from statistical physics

Becker

Ågren

Baricco

et al. 2013

Physica Status Solidi (b)

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We describe current approaches to thermodynamic modelling of liquids for the CALPHAD method, the use of available experimental methods and results in this type of modelling, and considerations in the use of atomic-scale simulation methods to inform a CALPHAD approach. We begin with an overview of the formalism currently used in CALPHAD to describe the temperature dependence of the liquid Gibbs free energy and outline opportunities for improvement by reviewing the current physical understanding of the liquid. Brief descriptions of experimental methods for extracting high-temperature data on liquids and the preparation of undercooled liquid samples are presented.Properties of a well-determined substance, B 2 O 3 , including the glass transition, are then discussed in detail to emphasize specific modelling requirements for the liquid. We then examine the two-state model proposed for CALPHAD in detail and compare results with experiment and theory, where available. We further examine the contributions of atomic-scale methods to the understanding of liquids and their potential for supplementing available data. We discuss molecular dynamics (MD) and Monte Carlo methods that employ atomic interactions from classical interatomic potentials, as well as contributions from ab initio MD. We conclude with a summary of our findings.1 Introduction Although few inorganic materials are used in their liquid state, liquids play an important role in the manufacture of many materials. This can be either because they are processed from the liquid or, for fulfilling performance criteria, the formation of the liquid phase must be avoided. Additionally, there are now a number of commercially available amorphous solids, both in the form of oxides and metallic glasses, and accurate descriptions of these sys-tems are necessary over a wide range of temperatures. How-ever, liquid phases of many inorganic substances are only sta-ble at high temperatures where the experimental determination of their properties is more challenging than at lower tem-peratures. Many amorphous phases are, at best, metastable and their properties can be difficult to measure. In addition, the data from glassy phases cannot be directly applied to modelling liquids because they have gone through the glass transition, with the attendant sharp drop in heat capacity. As a result, the experimental data for generating and evaluating models of liquids and glasses are fairly sparse. This has a significant impact on the development and refinement of models that strongly depend on the availability of thermodynamic data, such as those needed in CALPHAD modelling.CALPHAD is one of the major ways to model the thermodynamics of liquids. However, for many systems, especially the unaries (elements and sometimes compounds), the data necessary to develop, parameterize and validate models are limited. Theoretical approaches, e.g. first-principles or classical atomistic simulation, can help provide data

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“…While a comprehensive review is outside the scope of this paper, Cheng and Ma [37] published a thorough review of metallic glass research in 2011.…”

Section: Glasses and The Glass Transitionmentioning

confidence: 99%

Thermodynamic modelling of liquids: CALPHAD approaches and contributions from statistical physics

Becker

Ågren

Baricco

et al. 2013

Physica Status Solidi (b)

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“…Similar to Eq. (4), a parabolic relationship, δ = (0.088 ± 0.003)η Mises + (0.439 ± 0.014)(η Mises ) 2 , can describe the shear-dilatation during deformation fairly well. So that we confirm the shear-dilatation correlation during deformation as well as the static spatial correlation summarized in Figs.…”

mentioning

confidence: 92%

“…The deformation mechanisms of such amorphous solid state are in sharp contrast with their crystalline counterparts since there are no long-range atoms packing pattern in MGs [2,3]. No conventional mechanisms, such as ordinary dislocation plasticity or deformation twinning in crystals, exist in MGs which can carry plastic deformation.…”

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confidence: 99%

Direct atomic-scale evidence for shear–dilatation correlation in metallic glasses

et al. 2016

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Direct atomic-scale evidence is presented for the shear-dilatation correlation in metallic glasses via molecular dynamics and first-principles calculations. A quantitative parabolic relationship is established between the atomic local shear and hydrostatic volumetric strains by carrying out statistical analysis on a deformed glass model. The correction is further verified by density functional theory. Our atomistic demonstration of shear-dilatation correlation collaborates with the experimentally observed a few percent volume change in shear bands. It brings quantitative insights into the unique correlation between shear transformation and cavitation in metallic glasses.© 2015 Elsevier Ltd. All rights reserved.Metallic glasses (MGs) are a category of promising high strength structural materials with many other superior physical and chemical properties [1]. The deformation mechanisms of such amorphous solid state are in sharp contrast with their crystalline counterparts since there are no long-range atoms packing pattern in MGs [2,3]. No conventional mechanisms, such as ordinary dislocation plasticity or deformation twinning in crystals, exist in MGs which can carry plastic deformation. Therefore MGs usually suffer from the notorious catastrophic failure with a strong strain localization (shear banding) phenomenon [4,5].Several models have been proposed to rationalize the inelastic deformation of MGs, which include free volume [6], shear transformation zone (STZ) [7][8][9], cooperative shear model (CSM) [10,11], flow unit [12], vibrational soft spot [13], shear-diffusive transformation [14,15], and our recently proposed tensile transformation zone (TTZ) [16][17][18]. All of these models are based on the local structural rearrangement of atoms via the interplay of atomic-scale shear and dilation/contraction in MGs [19][20][21][22][23][24]. Among them, Argon's STZ model involves local rearrangement of a cluster of atoms undergoing a stress-driven, and thermally activated shear distortion [25,23,24]. Whereas Spaepen's free volume model is based on a dynamic equilibrium between the stress-assisted creation and annihilation of free volume [6]. The free volume behaviors can be regarded as dilation and contraction of local atomic environments. Since both models have been successfully adopted to describe the homogeneous and inhomogeneous flows in MGs, there should be some intrinsic correlation between shear and dilatation/compaction during deformation of glasses [21,26].Generally, shear-dilatation correlation is an intrinsic nature of deformation in amorphous alloys although local compaction is also allowed [27,28]. For example, intuitively derived law between shear strain and local dilatation has been used in constitutive modelings of MGs [29]. Shear is not necessarily the only deformation mode accommodating the local atomic rearrangement. The microscopic scenario is that the STZ operations redistribute stress spatially which usually leads to the creation of free volume via atomic-scale dilatation [21,1]. So that local ...

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“…The one thing that unites all of the alloy compositions is the presence of an element couple with a positive heat of mixing (Cu-Fe, Co, Ni). Such a composition design feature is known to induce local structural instability and increase the heterogeneity of the metallic glass [15][16][17] . The influence of thermal cycling on the mechanical properties of the selected metallic glasses was investigated in the present work.…”

Section: Introductionmentioning

confidence: 99%

On cryothermal cycling as a method for inducing structural changes in metallic glasses

et al. 2018

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The influence of cryothermal treatment on the mechanical properties of metallic glasses with different compositions was investigated in the present work. It was found that cryothermal cycling can induce rejuvenation as well as relaxation of the metallic glasses. The local apparent Young's modulus and its spatial distribution width on the surface of the metallic glass increase after cryothermal cycling, while in the bulk the effect depends on the glass composition. It appeared that this increase is temporary and disappears after a period of room temperature aging. This effect is connected with a large distribution of relaxation times in the metallic glasses due to their heterogeneous structure and the formation of complex native oxides on the outer surfaces of the glasses. Our findings reveal that a cryothermal cycling treatment can improve or degrade the plasticity of a metallic glass, and the atomic bond structure appears to be very important for the outcome of the treatment.

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Atomic-level structure and structure–property relationship in metallic glasses

Cited by 1,509 publications

References 472 publications

Thermodynamic modelling of liquids: CALPHAD approaches and contributions from statistical physics

Thermodynamic modelling of liquids: CALPHAD approaches and contributions from statistical physics

Direct atomic-scale evidence for shear–dilatation correlation in metallic glasses

On cryothermal cycling as a method for inducing structural changes in metallic glasses

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