Towards understanding of heat effects in metallic glasses on the basis of macroscopic shear elasticity

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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Heat Effects Occurring in the Supercooled Liquid State and Upon Crystallization of Metallic Glasses as a Result of Thermally Activated Evolution of Their Defect Systems

Metals ◽

10.3390/met10030417 ◽

2020 ◽

Vol 10 (3) ◽

pp. 417 ◽

Cited By ~ 1

Author(s):

Andrei Makarov ◽

Gennadii Afonin ◽

Yurii Mitrofanov ◽

Nikolai Kobelev ◽

Vitaly Khonik

Keyword(s):

Metallic Glasses ◽

Liquid State ◽

Supercooled Liquid ◽

Shear Moduli ◽

Thermally Activated ◽

Supercooled Liquid State ◽

Heat Effects ◽

Temperature Dependences ◽

Defect System ◽

Kinetics Of

We show that the kinetics of endothermal and exothermal effects occurring in the supercooled liquid state and upon crystallization of metallic glasses can be well reproduced using temperature dependences of their shear moduli. It is argued that the interrelation between the heat effects and shear modulus relaxation reflects thermally activated evolution of interstitial-type defect system inherited from the maternal melt.

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On the nature of heat effects and shear modulus softening in metallic glasses: A generalized approach

Journal of Applied Physics ◽

10.1063/1.4862399 ◽

2014 ◽

Vol 115 (3) ◽

pp. 033513 ◽

Cited By ~ 26

Author(s):

N. P. Kobelev ◽

V. A. Khonik ◽

A. S. Makarov ◽

G. V. Afonin ◽

Yu. P. Mitrofanov

Keyword(s):

Shear Modulus ◽

Metallic Glasses ◽

Heat Effects

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Thermodynamic approach for the understanding of the kinetics of heat eﬀects induced by structural relaxation of metallic glasses

Journal of Physics Condensed Matter ◽

10.1088/1361-648x/ac4628 ◽

2021 ◽

Author(s):

Andrey Makarov ◽

Gennadii V Afonin ◽

Alexander S Aronin ◽

Nikolai Kobelev ◽

Vitaly A Khonik

Keyword(s):

Shear Modulus ◽

Metallic Glasses ◽

Structural Relaxation ◽

Entropy Change ◽

Free Energy Barrier ◽

Novel Approach ◽

Heat Effects ◽

Kinetics Of ◽

Good Agreement ◽

Non Equilibrium

Abstract We present a novel approach to the understanding of heat eﬀects induced by structural relaxation of metallic glasses. The key idea consists in the application of a general thermodynamic equation for the entropy change due to the evolution of a non-equilibrium part of a complex system. This non-equilibrium part is considered as a defect subsystem of glass and its evolution is governed by local thermoactivated rearrangements with a Gibbs free energy barrier proportional to the high-frequency shear modulus. The only assumption on the nature of the defects is that they should provide a reduction of the shear modulus – a diaelastic eﬀect. This approach allows to determine glass entropy change upon relaxation. On this basis, the kinetics of the heat eﬀects controlled by defect-induced structural relaxation is calculated. A very good agreement between the calculation and specially performed calorimetric and shear modulus measurements on three metallic glasses is found.

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