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

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. © 2022 IOP Publishing Ltd.

Citation

A S Makarov, G V Afonin, A S Aronin, N P Kobelev, V A Khonik. Thermodynamic approach for the understanding of the kinetics of heat effects induced by structural relaxation of metallic glasses. Journal of physics. Condensed matter : an Institute of Physics journal. 2022 Jan 07;34(12)

PMID: 34942612

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