Article
Chemistry, Physical
N. P. Kobelev, J. C. Qiao, A. S. Makarov, A. M. Glezer, V. A. Khonik
Summary: The study reports measurements of internal friction and shear modulus of glassy Cu49Hf42Al9 at different frequencies and temperatures. It is found that the relaxation of internal friction and shear modulus decreases with increasing frequency in the investigated range. A new method for determining the Gibbs activation energy of relaxation is derived, and the underlying activation energy spectrum is found to smoothly increase with accessible activation energies in the experiment.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Hongbo Zhou, Vitaly Khonik, Gerhard Wilde
Summary: Pd40Ni40P20 (at.%) samples with different enthalpy states were fabricated through high-pressure torsion or sub-T-g annealing. The structural relaxation was studied using in-situ shear modulus measurements and modulated differential scanning calorimetry. It was found that high-pressure torsion leads to shear modulus softening and structural rejuvenation, while sub-T-g annealing causes shear modulus hardening and structural relaxation.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
A. S. Makarov, R. A. Konchakov, J. C. Qiao, A. N. Vasiliev, N. P. Kobelev, V. A. Khonik
Summary: This study investigates the relationship between defect concentration and the structure factor of glasses based on shear modulus measurements and molecular dynamics simulation. The results show that defect-induced disordering is independent of glass thermal prehistory above the glass transition temperature, while significant differences exist between initial and relaxed samples below the transition temperature.
Article
Chemistry, Physical
Andrei Makarov, Gennadii Afonin, Konstantin Zakharov, Alexander Vasiliev, Jichao Qiao, Nikolai Kobelev, Vitaly Khonik
Summary: Experimental results show the existence of a boson heat capacity peak located near 7 K in high entropy bulk metallic glass, with the height decreasing upon preannealing. The study demonstrates that the height of the boson peak increases linearly with excess entropy and concentration of interstitial-type defects, attributing this to the high entropy state of the glass under investigation.
Article
Materials Science, Ceramics
A. S. Makarov, G. Afonin, R. A. Konchakov, J. C. Qiao, A. S. Aronin, N. P. Kobelev, V. A. Khonik
Summary: This study conducted parallel measurements of enthalpy and high-frequency shear modulus changes during structural relaxation of five bulk metallic glasses. The analysis revealed a one-to-one correlation between the change in molar enthalpy and the alteration in the calculated number of defects based on Interstitialcy theory. The defect formation enthalpy derived from this correlation aligns well with the accepted quantity in the Interstitialcy theory.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Materials Science, Ceramics
Hao Wang, Chengliang Zhao, Chuntao Chang, Shengli Zhu, Zhankui Zhao
Summary: The relationship between the heterogeneous structure and structural relaxation in metallic glasses was explored by investigating the quasielastic and viscoelastic behavior of a Zr55Cu30Ni5Al10 metallic glass. Stress-annealing treatment was used to retain elastic strain energy, and a unique creep recovery phenomenon was observed during the reheating process. The Maxwell model was employed to qualitatively describe the mechanisms of elastic strain energy retention and release.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2024)
Article
Nanoscience & Nanotechnology
M. Gao, J. H. Perepezko
Summary: The study reported a unique trimodal distribution of shear band nucleation events in a Gd-based metallic glass, providing insights into the relationship between the heterogeneous structure, relaxation kinetics, and deformation mechanism. The analysis of nucleation kinetics revealed the site density, nucleation rate, and activation barrier for three nucleation events, clearly displaying the trimodal character.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Fu Xu, Yizhou Liu, Botao Dai, Yanhuai Ding, Celal Kursun, Meng Gao
Summary: In this study, an in-situ tensile platform coupled with a nanoindenter was used to investigate the continuous loading and creep behaviors of Cu50Zr50 metallic glass film under different pre-tensile strains. The volume, activation volume, and relaxation time spectrum of shear transformation zones were determined based on models. The results showed that all three factors increase with pre-tensile strain.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Andrei Makarov, Marina Kretova, Gennadii Afonin, Nikolai Kobelev, Vitaly Khonik
Summary: This study conducted high-precision measurements of the temperature dependences of the shear modulus G in bulk metallic glass. It found that plastic deformation significantly affects the anharmonic, electronic, and relaxation components of G, with the relaxation contribution increasing, anharmonic component increasing, and electronic component decreasing.
Article
Materials Science, Ceramics
Wen-Ping Wu, D. Sopu, X. Yuan, O. Adjaoud, K. K. Song, J. Eckert
Summary: This paper studies the tensile creep behavior of Cu64Zr36 metallic glass through molecular dynamics simulations, discussing the effects of stress and temperature on activated states evolution, predicting creep failure time, and identifying three creep mechanisms. The study reveals that different stress and temperature regimes are dominated by various creep mechanisms involving atomic diffusion, anelastic deformation, and local inhomogeneous shear deformation. These mechanisms help to understand the creep behavior and describe the relationship between creep behavior and mechanical relaxations in metallic glasses.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
Huaping Sheng, Long Zhang, Haifeng Zhang, Jianbo Wang, Juergen Eckert, Christoph Gammer
Summary: The transformation-induced plasticity is a fundamental solution for improving the ductility of bulk metallic glass composites (BMGCs). The transformation redistributes the stress in the adjacent matrix, making interfacial regions potential preferential sites for shear band nucleation, which then enhance the ductility of BMGCs.
MATERIALS RESEARCH LETTERS
(2021)
Article
Metallurgy & Metallurgical Engineering
Jiang Minqiang, Gao Yang
Summary: Metallic glasses are formed through deep undercooling of high-temperature melt, residing in metastable energy states far from thermodynamic equilibrium, with remarkable mechanical, physical, and chemical properties. However, they are prone to localized plastic deformation and ageing-induced brittleness at room temperature, which can be improved by rejuvenation mechanism to enhance global plasticity.
ACTA METALLURGICA SINICA
(2021)
Article
Materials Science, Multidisciplinary
Harald Roesner, Christian Kuebel, Stefan Ostendorp, Gerhard Wilde
Summary: This study investigates the plastic deformation of metallic glasses through the formation of shear bands. It is found that the observed contrast of shear bands is related to thickness reduction rather than density changes, which may affect the interpretation of shear band properties. The observation of a spearhead-like shear front suggests a mechanism for shear band initiation.
Article
Materials Science, Ceramics
R. A. Konchakov, A. S. Makarov, G. V. Afonin, J. C. Qiao, M. G. Vasin, N. P. Kobelev, V. A. Khonik
Summary: The high-frequency shear modulus of different metallic glasses was measured and fluctuations in thermal energy near the glass transition were observed, suggesting characteristics of a continuous phase transition.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Nanoscience & Nanotechnology
Snigdha S. Jagarlapudi, Heaven S. Cross, Tridip Das, William A. Goddard
Summary: Environmental and toxicity concerns necessitate the replacement of DEHP plasticizer with potential alternatives such as DHS, DEA, 1,4-BDB, and DBS for PVC. The comparison of their tensile, mechanical, and diffusional properties is crucial in determining their competitiveness. This study predicts the effects of these plasticizers on various properties of PVC, and concludes that DBS and DHS show promising potential as green plasticizers for PVC.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Y. J. Duan, J. C. Qiao, D. Crespo, E. V. Goncharova, A. S. Makarov, G. V. Afonin, V. A. Khonik
JOURNAL OF ALLOYS AND COMPOUNDS
(2020)
Article
Chemistry, Physical
A. S. Makarov, Yu. P. Mitrofanov, E. V. Goncharova, J. C. Qiao, N. P. Kobelev, A. M. Glezer, V. A. Khonik
Article
Physics, Condensed Matter
A. S. Makarov, R. A. Konchakov, Yu P. Mitrofanov, M. A. Kretova, N. P. Kobelev, V. A. Khonik
JOURNAL OF PHYSICS-CONDENSED MATTER
(2020)
Article
Chemistry, Physical
V. A. Khonik
Summary: Professor A.V. Granato is a key scientist known for his contributions to understanding dislocation relaxations in crystals. He also proposed the Interstitialcy theory (IT) which offers new insights on melting, equilibrium/supercooled liquids and glasses in relation to the maternal crystalline state. This theory's origins, basic results, and recent developments are briefly discussed in the article.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Multidisciplinary
R. A. Konchakov, A. S. Makarov, A. S. Aronin, N. P. Kobelev, V. A. Khonik
Summary: Molecular dynamics simulations of aluminum near its melting point show a significant increase in vibrational entropy of interstitial defects with dumbbell configuration. By estimating the density of these defects in the melt through three independent methods, the configurational entropy of the system with defects is determined. Approximately 70% of the total entropy of melting can be attributed to the generation of interstitial dumbbells at T = T-m.
Article
Materials Science, Ceramics
A. S. Makarov, G. Afonin, R. A. Konchakov, J. C. Qiao, A. S. Aronin, N. P. Kobelev, V. A. Khonik
Summary: This study conducted parallel measurements of enthalpy and high-frequency shear modulus changes during structural relaxation of five bulk metallic glasses. The analysis revealed a one-to-one correlation between the change in molar enthalpy and the alteration in the calculated number of defects based on Interstitialcy theory. The defect formation enthalpy derived from this correlation aligns well with the accepted quantity in the Interstitialcy theory.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Physics, Condensed Matter
A. S. Makarov, J. C. Qiao, N. P. Kobelev, A. S. Aronin, V. A. Khonik
Summary: This study focuses on the fragility of supercooled liquids, demonstrating the relationship between fragility and high-frequency shear modulus. The heat capacity jump is also found to be related to fragility and shear modulus relaxation. The results suggest that the evolution of interstitial-type defects frozen-in during glass production mediates the connection between fragility, heat capacity jump, and high-frequency shear modulus in the supercooled liquid state.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Chemistry, Physical
N. P. Kobelev, J. C. Qiao, A. S. Makarov, A. M. Glezer, V. A. Khonik
Summary: The study reports measurements of internal friction and shear modulus of glassy Cu49Hf42Al9 at different frequencies and temperatures. It is found that the relaxation of internal friction and shear modulus decreases with increasing frequency in the investigated range. A new method for determining the Gibbs activation energy of relaxation is derived, and the underlying activation energy spectrum is found to smoothly increase with accessible activation energies in the experiment.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Physics, Condensed Matter
A. S. Makarov, G. Afonin, J. C. Qiao, A. M. Glezer, N. P. Kobelev, V. A. Khonik
Summary: By performing calorimetric and shear modulus measurements on bulk metallic glasses, this study demonstrates the consistency between the calorimetric determination and calculation of excess thermodynamic potentials, with a focus on the physical origin of these potentials being related to a system of interstitial-type defects frozen-in from the liquid state. The estimates of defect formation enthalpy and entropy indicate that the enthalpy scales with the shear modulus while the entropy is significantly large, aligning with the basic assumptions of the interstitialcy theory.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Physics, Condensed Matter
A. S. Makarov, G. Afonin, A. S. Aronin, N. P. Kobelev, V. A. Khonik
Summary: A novel approach is presented in this paper to understand the heat effects caused by structural relaxation of metallic glasses. By applying a general thermodynamic equation, the entropy change in glass relaxation can be determined, and the kinetics of the heat effects controlled by defect-induced structural relaxation can be calculated. The experimental results show a good agreement with the calculated results.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
Andrei Makarov, Marina Kretova, Gennadii Afonin, Nikolai Kobelev, Vitaly Khonik
Summary: This study conducted high-precision measurements of the temperature dependences of the shear modulus G in bulk metallic glass. It found that plastic deformation significantly affects the anharmonic, electronic, and relaxation components of G, with the relaxation contribution increasing, anharmonic component increasing, and electronic component decreasing.
Article
Nanoscience & Nanotechnology
A. S. Makarov, G. V. Afonin, R. A. Konchakov, V. A. Khonik, J. C. Qiao, A. N. Vasiliev, N. P. Kobelev
Summary: By introducing a dimensionless order parameter 4, the structural order of glass can be estimated, and this parameter shows a strong correlation with the glass-forming ability.
SCRIPTA MATERIALIA
(2024)
Article
Chemistry, Physical
A. S. Makarov, R. A. Konchakov, J. C. Qiao, A. N. Vasiliev, N. P. Kobelev, V. A. Khonik
Summary: This study investigates the relationship between defect concentration and the structure factor of glasses based on shear modulus measurements and molecular dynamics simulation. The results show that defect-induced disordering is independent of glass thermal prehistory above the glass transition temperature, while significant differences exist between initial and relaxed samples below the transition temperature.
Article
Physics, Multidisciplinary
G. V. Afonin, Yu. P. Mitrofanov, N. P. Kobelev, V. A. Khonik
JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS
(2020)
Article
Physics, Multidisciplinary
M. A. Kretova, R. A. Konchakov, N. P. Kobelev, V. A. Khonik