Evolution of the activation energy spectrum and defect concentration upon structural relaxation of a metallic glass determined using calorimetry and shear modulus data

Макаров, А. С.; Afonin, G.V.; Mitrofanov, Yu.P.; Кончаков, Р. А.; Кобелев, Н. П.; Qiao, J.C.; Khonik, V. A.

doi:10.1016/j.jallcom.2018.02.176

Cited by 7 publications

(5 citation statements)

References 54 publications

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“…The quasi-equilibrium balance between all these clusters will be dependent on temperature and thermal prehistory defining the evolution of glass properties [83,84]. Some qualitative estimates of clustering kinetics are given elsewhere [85,86]. Further detailed work in this direction is challenging.…”

Section: Development Of the Interstitialcy Theorymentioning

confidence: 99%

Metallic Glasses: A New Approach to the Understanding of the Defect Structure and Physical Properties

Khonik

Кобелев

2019

Metals

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The work is devoted to a brief overview of the Interstitialcy Theory (IT) as applied to different relaxation phenomena occurring in metallic glasses upon structural relaxation and crystallization. The basic hypotheses of the IT and their experimental verification are shortly considered. The main focus is given on the interpretation of recent experiments on the heat effects, volume changes and their link with the shear modulus relaxation. The issues related to the development of the IT and its relationship with other models on defects in metallic glasses are discussed.

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Section: Development Of the Interstitialcy Theorymentioning

confidence: 99%

Metallic Glasses: A New Approach to the Understanding of the Defect Structure and Physical Properties

Khonik

Кобелев

2019

Metals

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“…The idea that clustering of the interstitial defect structure may play a crucial role in different relaxation processes occurring in MGs was already suggested in [63,64]. However, it is reasonable to assume that the main features of interstitial clusters (shear susceptibility and vibrational spectra) may be dependent on the cluster size.…”

Section: Origin Of the Icosahedral Ordering Within The Framework Of T...mentioning

confidence: 99%

Interstitial clustering in metallic systems as a source for the formation of the icosahedral matrix and defects in the glassy state

Кончаков

Макаров

Кобелев

et al. 2019

J. Phys.: Condens. Matter

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The paper presents molecular dynamics and -statics simulations of a prototypical mono-atomic metallic system (aluminum) and its defects in the crystalline and glassy states. It is shown that there is a thermodynamic driving force for the association of dumbbell interstitials in the crystalline lattice into clusters consisting of different amounts of defects. Clusters containing seven interstitials constitute perfect icosahedra. Within the general framework of the interstitialcy theory, melting of simple metallic crystals is intrinsically related to a rapid increase of the concentration of dumbbell interstitials, which remain identifiable structural units in the liquid state. Then, the glass produced by rapid melt quenching contains interstitial-type defects. The idea of the present work is to argue that the major structural feature of many metallic glasses—icosahedral ordering—originates from the clustering of interstitial-type defects frozen-in upon melt quenching. Separate defects and their small clusters represent the defect part of the glassy structure.

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“…Tremendous efforts have been made to examine the correlations between the local atomic relaxations and those "defects". 15,20−22 On the other hand, it is known that many macroscopic properties of MGs (e.g., heat release/absorption, 23,24 homogeneous deformation, 13 etc.) are actually governed by the overall structural distributions and activation energy (E A ) spectra, rather than by some extreme "defects", which are located near the ends of the spectra.…”

mentioning

confidence: 99%

“…In fact, the definition of “defects” in disordered materials is obscure and not unique: examples include free volume (FV), , shear transformation zones (STZs), − Voronoi tessellation, , flow units, , soft modes/spots, − regions with large fluctuations of atomic level stresses, , etc. Tremendous efforts have been made to examine the correlations between the local atomic relaxations and those “defects”. ,− On the other hand, it is known that many macroscopic properties of MGs (e.g., heat release/absorption, , homogeneous deformation, etc.) are actually governed by the overall structural distributions and activation energy ( E A ) spectra, rather than by some extreme “defects”, which are located near the ends of the spectra.…”

mentioning

confidence: 99%

“…Through the medium of the PEL, the soft-mode parameter Ψ can be proposed as a good predictor of metallic glass properties, such as the shear modulus G . Furthermore, the capability of establishing a quantitative description on P ( E A ) is critical, because as discussed above, it determines many macroscopic thermomechanical properties of amorphous solids. ,, Although the study presented here does not yet give an explicit formalism of P ( E A ), it provides effective guidance toward such a goal. The hereby obtained correlations and uncertainty quantifications, in conjunction with machine learning tools, are expected to enable an analytical and accurate expression of P ( E A ) in the future.…”

mentioning

confidence: 99%

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Soft-Mode Parameter as an Indicator for the Activation Energy Spectra in Metallic Glass

Shan

Liu

Fan

et al. 2020

J. Phys. Chem. Lett.

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The activation energy (EA) spectra of potential energy landscape (PEL) provides a convenient perspective for interpreting complex phenomena in amorphous materials; however, the link between the EA spectra and other physical properties in metallic glasses is still mysterious. By systematically probing the EA spectra for numerous metallic glass samples with distinct local geometric ordering, which correspond to broad processing histories, it is found that the shear modulus of the samples are strongly correlated with the arithmetic mean of the EA spectra rather than with the local geometrical ordering. Furthermore, we studied the correlation of the obtained EA spectra and various wellestablished physical parameters. The outcome of our research clearly demonstrates that the soft mode parameter Ψ and the EA spectrum are correlated; therefore, it could be a good indicator of metallic glass properties and sheds important light on the structure-property relationship in metallic glass through the medium of PEL. TOC GraphicMetallic glasses (MGs), as metastable systems, can provide ample opportunity for property control that can be used in structural and functional applications 1-8 . However, due to their inherent nature of disordered atomic packing and, consequently, the absence of conventional defects with distinctive topologies (e.g. dislocations, grain boundaries, etc.), it is very difficult to establish a "crystal clear" structure-property relationship for MGs. In fact, the definition of "defects" in disordered materials are obscure and not unique: examples include free volume (FV) 9-10 , shear transformation zones (STZ) 11-15 , Voronoi tessellation 16-17 , flow units 18-20 , soft modes/spots 21-23 , regions with large fluctuations of atomic level stresses 24-26 , etc. Tremendous efforts have been made in the past to examine the correlations between the local atomic relaxations and those "defects" 21, 27-30 . On the other hand, it is known that many macroscopic properties of MGs (e.g.heat release/absorption 31-32 , homogeneous deformation 18 , etc.) are actually governed by the overall structural distributions and activation energy (EA) spectra, rather than by some extreme "defects", which are located near the ends of the spectra. From the PEL perspective, the relaxation process can be pictured as the transitions between the deep 'metabasins', whereas the relaxation process refers to the elementary hopping event between the 'sub-basins'coded within a metabasin. These processes are related to many important properties, such as glass transition, deformation, aging and rejuvenation etc., of MGs. Systematically analyzing the activation energy (EA) spectra for these processes are extremely helpful for understanding some critical phenomena 33 , and establishing the microscopic structure-property connections. Therefore, important questions that follow and yet remain open are: how does the EA spectra correlate with the physical properties of interest in MGs, and what are the most effective structural indicators in determining...

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Evolution of the activation energy spectrum and defect concentration upon structural relaxation of a metallic glass determined using calorimetry and shear modulus data

Cited by 7 publications

References 54 publications

Metallic Glasses: A New Approach to the Understanding of the Defect Structure and Physical Properties

Metallic Glasses: A New Approach to the Understanding of the Defect Structure and Physical Properties

Interstitial clustering in metallic systems as a source for the formation of the icosahedral matrix and defects in the glassy state

Soft-Mode Parameter as an Indicator for the Activation Energy Spectra in Metallic Glass

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