bluuebunny/crossref_metadata_2025 huggingface dataset:
IMPROVING THE SYSTEM OF INDICATORS FOR ASSESSING THE ECONOMIC SUSTAINABILITY OF THE ENTERPRISE IN THE CONDITIONS OF DIGITAL TRANSFORMATION
Authors:   State University of Intellectual Technologies and Communication, Odesa, Knyazyeva O. A.
Published: April 2024

It has been proven that the existing indices and methods for assessing the level of digitization at the macro level are based on technical indicators and almost do not take into account most socio-economic aspects, the specifics of countries and regions, the level of development of national economic systems and their investment attractiveness, the degree of influence of state supervision and regulation, and other factors. The need for the formation of indicators that will determine the macro- and micro-level quantitative values of the state and effectiveness of digital transformation in general and economic sustainability in particular is substantiated. It has been established that electronic communications operators in their activities apply general approaches to assessing the level of economic sustainability, but have specific requirements for ensuring their own economic sustainability as such and sustainability from the point of view of the ability to ensure digitalization processes. An improved system of indicators is proposed, which has been refined due to the addition of a new group, which together can determine the economic sustainability of the enterprise under the conditions of digital transformations. This group includes: profitability ratio of digital assets (determining the share of revenues attributable to digital assets of the enterprise in total revenues), profitability ratio of digital investments (effectiveness of investing in digital assets as a source of additional profit in terms of diversification of the enterprise’s activities), turnover ratio of digital assets currencies (activity of the enterprise on the market of digital assets and the efficiency of their use for obtaining additional income in this segment of the digital market), the efficiency coefficient of online management tools (the level of influence of digital services on the controllability of the system and the overall efficiency of management), the level of protection against cyber incidents (the presence of and the effectiveness of the security system of economic, organizational, social and other processes against unauthorized network interference, which can cause a number of problems). The economic essence, meaningful content, methodical tools and limit values of the indicators are presented. The latter are formed on the basis of the analysis of similar or close to the proposed indicators for enterprises of Ukraine and the world.
IMPACT OF DIGITAL ECONOMY ON BUSINESS MODELS AND FINANCIAL MANAGEMENT: INSTITUTIONALIZATION OF DIGITAL TRANSFORMATIONS
Authors:   Taras Shevchenko National University of Kyiv, Kyiv, Chubuk L. P.
Published: April 2024

The digital economy has truly revolutionized traditional business models and financial management practices, driving the institutionalization of digital transformations across various sectors. This article examines the impact of digitization on business models and financial management, considering the underlying mechanisms and consequences. The relevance of this topic lies in the comprehensive influence of digital technologies on contemporary business trends. Businesses increasingly leverage digital platforms, data analytics, and automation, making an understanding of digital transformation essential for both practitioners and researchers. Moreover, the COVID-19 pandemic has accelerated the adoption of digital tools, further emphasizing the importance of studying their impact on business practices. A comprehensive analysis of scholarly literature and empirical research results has led to several key conclusions. Firstly, digitization alters business models, providing greater adaptability, customization, and scalability. Organizations utilize digital platforms to enter new markets, personalize offerings, and optimize operations. Secondly, digital technologies significantly impact financial management practices, enhancing real-time data analysis, risk assessment, and decision-making processes. Automated financial systems optimize resource allocation, mitigate risks, and improve financial performance. The research results indicate that the institutionalization of digital transformations is a multi-faceted process influenced by organizational culture, leadership, and external factors. Successful integration of digital technologies requires strategic alignment, organizational resilience, and continuous innovation. Digitization presents both opportunities and challenges for businesses, necessitating adaptive strategies and proactive management approaches. Future research prospects lie in studying specific industries and organizational processes to explore the impact of digitization on business models and financial management in various aspects.
LOGISTICS PROCESSES’ OPTIMIZATION IN INTERNATIONAL TRADE
Authors:   State University of Information and Communication Technologies, Kyiv, Nikolenko I. Yu.
Published: April 2024

Scientific article devoted to the main principles’ and tasks’ substantiation for logistics activities in international trade. In the research has been determined the functional components of international logistics in terms of the study of key threats, risks of the logistics companies’ operation in the field of international trade. It have been identified the fundamental goals and tools of logistics systems optimization, which are used by modern enterprises to reduce costs, increase the level of efficiency and improve the quality of customer service. It was determined that the global economy provides a huge number of opportunities for business strategic development, whereas international trade and exporting are becoming increasingly important components of successful entrepreneurship in the modern world. In order to successfully conduct international trade, in the article have been taken into account the practical recommendations related to international supply and logistics. International trade and logistics has been defined as the main factor, which plays an important role in the successful of the global economy functioning and then requires specific knowledge and skills to achieve success. In turn, international business requires special attention to logistics and supply and it is positioned as a number of complex challenges for companies in moving goods and services between different countries. Summarizing, it worth to noting that international trade and logistics are interconnected and jointly determine the success of global business. They enable companies to expand their market and reach new heights by ensuring efficient sourcing and international distribution of goods and services, and accordingly, the components optimal combination of this interconnected process allows companies to expand their own shares of the target market and, as a result, achieve sustainable competitive advantages, ensuring the effective distribution of goods and services at the national and global levels.
STRATEGIC CRITERIA FOR ASSESSING THE MANAGEMENT OF TELECOMMUNICATIONS ENTERPRISES IN THE DIGITAL ECONOMY
Authors:   State University of Information and Communication Technologies, Kyiv, Sazonova S. V.
Published: April 2024

The relevance of the chosen research topic is due to the insufficient conceptual development of the paradigm of strategic management of telecommunications enterprises in the digital economy. The article reveals the essence of defining and applying strategic criteria for assessing the management of telecommunications enterprises. It is determined that the essence lies in the ability to predict the business situation, prevent the negative impact of internal and external factors, introduce measures to minimize costs, ensure the achievement of the set goals and, above all, obtain a positive financial result of the enterprise's activity - the desired profit. The article argues that the digital economy, which is spreading through active digitalization and is based on the activities of telecommunications enterprises, gives rise to a new type of strategic management and leads to profound changes in how telecommunications enterprises should be organized today and managed in the future. The article describes the current trends that already have a major impact on the organization of telecommunications enterprises and will shape changes in the strategic management of telecommunications enterprises in the near future. These circumstances require further scientific developments on the formation of new approaches to the strategic management of telecommunications enterprises and tools for their implementation based on strategic criteria for assessing the management of telecommunications enterprises in the context of the development of the digital economy. The author's approach to determining the directions of digitalization's impact on the activities of telecommunications enterprises is proposed, which allows to outline the strategic criteria for assessing the management of telecommunications enterprises in the long term. The study allows us to conclude that the strategic management of telecommunication enterprises in the digital economy requires expanded monitoring and analysis of the external environment; enhancing the safety, protection and empowerment of citizens, ensuring freedom of choice on the Internet, continuous improvement and development of telecommunication devices and channels and integration of innovations; supporting participation in the digital public space by creating a digital environment in which interaction between participants takes place through digital services.
A Global Digital Compact for Democracy
Authors: Gibaja Alberto Fernández , Castellaro Sebastian Becker , Hammar Cecilia
Published: April 2024

Since technologies are not neutral, the principles underpinning digital technologies and their governance system are fundamental to protecting their capacity to foster, maintain and protect human rights. This Policy Paper identifies four areas of work that highlight the main opportunities for embracing democracy through an open and safe digital future as well as the challenges to doing so. These areas are: (a) closing the digital divide; (b) ensuring that human rights are the core value shaping the Global Digital Compact; (c) putting in place artificial intelligence governance that protects fundamental rights and democracy; and (d) advancing data governance for the common good.
Tin Bronze Reinforced with Cu9Al4 Particles:
Mechanochemical Synthesis and Consolidation
by Sintering under Pressure
Authors: Grigoreva T. F. , Kovaleva S. A. , Kvashnin V. I. , Petrova S. A. , Devyatkina E. T. , Vosmerikov S. V. , Zhornik V. I. , Vityaz P. A. , Lyakhov N. Z.
Published: April 2024

X-ray diffraction analysis and optical and electron microscopy have been used to study the effect of mechanical activation conditions of the Cu–12% Sn mixture with different Cu9Al4 modifier contents on the structure and phase composition and morphology of formed composites. The mechanochemical intro-duction of 10 wt % of the modifying additive into the matrix of mechanically synthesized tin bronze mainly results in the formation of a ternary Al0.05Cu0.9Sn0.05 solid solution of aluminum and tin in copper. In the case of the 20 wt % modifying additive, the final product contains a Cu0.9Sn0.1 tin solid solution in copper and Cu9Al4 intermetallics. Studies of the mechanical and tribological characteristics of the material prepared by sintering under a pressure showed that the intensity of wear of the material based on the Cu–12 wt % Sn mechanochemically synthesized bronze is insignificant lower than that of commercial bronze alloy CuSn10P; the coefficient of friction (f) decreases by ~1.3 times and the range of its values is sufficiently wide,f = 0.7–0.9. The modification of the Cu–12 wt % Sn mechanically synthesized bronze with the Cu9Al4 inter-metallics allowed us to decrease the intensity of wear by 1.3 to 1.6 times and to substantially decrease the coef-ficient of friction (by 1.2 to 1.6 times). The stable value f = 0.5 is reached for the mechanically activatedCu‒12 wt % Sn + 20 wt % Cu9Al4 composition. The introduction of the intermetallics results in the increase in the microhardness of the alloys by 1.6 to 2 times (to Hμ = 2730 MPa) compared to those of CuSn10P and mechanically synthesized bronzes.
The Magnetic Susceptibility of Alloys
Below the Percolation Threshold
Authors: Belokon V. I. , Dyachenko O. I. , Lapenkov R. V.
Published: April 2024

Within the theory of random interaction fields, the possibility of determining the Curie point and the paramagnetic Curie point corresponding to the appearance of short-range order is shown. In ferromag-netic alloys, there is a concentration range in which the long-range order is destroyed, but the short-range order persists. This leads to the appearance of a cluster glass phase, which is characterized by a time depen-dence of the magnetic susceptibility and the appearance of viscous magnetization. For an AuFe alloy as an example, the behavior of the initial magnetic susceptibility as a function of temperature and concentration is studied and compared with experimental data.
Structural Evolution of 10% Cr–3% Co Steel Microalloyed
with Re and Cu during Creep Au 923 К
Authors: Fedoseeva A. E.
Published: April 2024

Structural evolution of the tempered lath martensite of the 10% Cr--3% Co steel microalloyed with rhenium and copper with a low nitrogen content and a high boron content during creep at 923 K was investigated for the purpose of establishment of the rison of decrease in creep resistance of this steel under the low applied stress. The tempered martensite lath structure of 10%Cr-3%Co steel with an average lath size of 370 nm and a high dislocation number density of 2 ×1014 m–2 was observed after normalizing at 1323 K with the following tempering at 1043 K for 3 h. The structure was stabilized by M23C6 carbides, M6C carbides, and NbX carbonitrides. During long-term creep, the lath structure strongly experienced an evolution: the width of the martensitic laths increased significantly, dislocation density decreased, the Laves phase and Cu-enriched particles remarkably coarsen. Such structural evolution correlates with an appearance of creep strength breakdown on curves “Applied stress vs. Time to failure” and “Minimum creep rate vs. Applied stress”. Significant coarsening of the Laves phase particles and Cuenriched particles via formation of the large particles with sizes more than 250 nm along high-angle boundaries and full dissolution of the fine particles with sizes less than 50 nm along low-angle boundaries of martensite laths is considered to be the main cause of degradation of the creep resistance of the steel studied.
The Structure and Mechanical Properties
of the Aging Shape-Memory Ti49Ni51 Alloy
after Thermomechanical Treatment
Authors: Kuranova N. N. , Makarov V. V. , Pushin V. G. , Popov N. A.
Published: April 2024

The effect of thermomechanical treatment on the structure and phase transitions of the aging shape-memory Ti–51 at % Ni alloy has been studied. Mechanical tensile tests were performed in combina-tion with optical and electron microscopic and X-ray diffraction studies. An ultrafine grained (UFG) struc-ture was created in the alloy by multipass-rolling plastic deformation and further annealing. It was established for the alloy to have a high level of mechanical properties (ultimate tensile strength up to 1550 MPa at a rela-tive elongation of more than 20%) owing to a highly disperse phase of precipitation with the formation of an UFG structure due to recrystallization.
STRUCTURE AND PROPERTIES OF THE Al-Zn-Mg-Cu-Zr-Y(Er) ALLOYS SHEETS DOPED BY MANGANESE
Authors: Glavatskikh M. V. , Barkov R. Yu. , Khomutov M. G. , Pozdniakov A. V.
Published: April 2024

The structure and properties of rolled Zn-Mg-Cu-Zr-Y(Er) alloys alloyed with manganese and modified with titanium have been studied. According to the results of tensile tests in the deformed and annealed state at 120-150°C for one hour, AlZnMgCuMnTi and AlZnMgCuMnTiEr alloys have a high yield strength of 417-456 MPa with a small relative elongation of 2-5.2%. The presence of additional dispersant-forming elements of yttrium and erbium increases the particle precipitation density during homogenization annealing, increasing the temperature of the onset of recrystallization and the hardness of the rolled alloys. After one hour annealing at 350°С, the structure of the AlZnMgCuMnTi alloy is completely recrystallized, while recrystallization is just beginning in alloys with yttrium and erbium. After quenching from 465°C and aging at 120°C, the test alloys have a yield strength of more than 410 MPa, a tensile strength of more than 520 MPa, and an elongation of more than 10%. The obtained properties are higher than the properties of clad sheets of high-strength heat-strengthened alloy Al-Zn-Mg-Cu (B95A) and bars of AlZn4.5Mg1.5Mn and AlZnMg1.5Mn alloys and are at the level of properties of bars of Al-Zn-Mg-Cu alloy (B95).
Features of the Magnetic State of an Ordered Array of Ferromagnetic Ribbons
Authors: Orlov V. A. , Rudenko R. Yu. , Luk’yanenko A. V. , Yakovchuk V. Yu. , Komarov V. A. , Prokopenko V. S. , Orlova I. N.
Published: April 2024

The features of the magnetic state of an array of parallel oriented permalloy ribbons are discussed. The arrays are made by explosive lithography. The ribbons have a thickness of 180 nm, a width of 2.8 μm, and a length of about 4 mm. The distance between ribbons in different samples varies in the range from 300 nm to 4 μm. It is found that the ribbons in the regions far from the end faces are in a single-domain state with small-angle ripples, the magnetization distribution of which correlates with inhomogeneities of the ribbon side surfaces. Moreover, there is a distinct relationship in the spatial distribution of the ripples between adja-cent ribbons with a relatively small distance between them. This makes it possible to evaluate the role of the magnetostatic coupling of magnetic subsystems of array elements and to estimate the characteristic value of the random stray field that pins the magnetization.
An Effective Method of Magnetic Hyperthermia Based
on the Ferromagnetic Resonance Phenomenon
Authors: Stolyar S. V. , Li O. A. , Nikolaeva E. D. , Vorotynov A. M. , Velikanov D. A. , Knyazev Yu. V. , Bayukov O. A. , Iskhakov R. S. , P’yankov V. F. , Volochaev M. N.
Published: April 2024

Nickel and cobalt ferrite nanoparticles have been synthesized using the chemical precipitation method; the nanoparticle sizes were found to be 63 ± 22 and 26 ± 4 nm, respectively. The static hysteresis loops and Mössbauer spectra have been measured. It is shown that cobalt ferrite powders are magnetically harder than nickel ferrite powders. Ferromagnetic resonance (FMR) curves have been studied. It is found that the FMR absorption for cobalt ferrite is observed at room temperature and above. The time dependences of the nanoparticle warm-up under FMR conditions have been measured. The maximum temperature changes for nickel ferrite and cobalt ferrite particles are 8 and 11 K, respectively. Using the example of cobalt ferrite powder, the possibility of effectively heating of particles in the FMR mode in their own field without using a DC magnetic field source is shown. The observed effect can be used in magnetic hyperthermia.
The Effect of the Interface Width on the Exchange Interaction
Constant between Ferro- and Antiferromagnets
Authors: Il’yushin I. G. , Afremov L. L. , Kharitonov V. N.
Published: April 2024

Within the model of two-phase (core/shell) ellipsoidal nanoparticles, the effects of the interfacial exchange interaction, size, elongation, and orientation of the major axes of the core and shell on the meta-stability of magnetic states have been simulated. Using the example of Fe2.44Ti0.56O4 nanoparticles,Fe3O4 it is shown that the metastability of magnetic states is realized in a limited range of the constant of interfacial exchange interaction between the core and shell, Ain , and geometric parameters. With an increase in the absolute value of the interfacial exchange interaction constant, , from Ain = 0 to some finite value, theAin metastability of magnetic states decreases monotonically from maximum to zero, regardless of the angle between the major axes of the core and the shell.
The Influence of Production Technology on the Structure
and Mechanical Properties of Niobium–Silicon–Aluminum Alloys
Authors: Sapegina I. V. , Lubnin A. N. , Ladyanov V. I.
Published: April 2024

Cast Nb–14 at % Si–9 at % Al alloys fabricated by self-propagating high-temperature synthesis (SHS) and by SHS followed by electric arc remelting have been investigated. A structure consisting of a solid solution of silicon and aluminum in niobium (NbSS), a Nb3Al intermetallic compound, and a β-Nb5(Si,Al)3silicide formed in the alloy fabricated by SHS. Electric arc remelting suppressed the formation of the Nb3Alphase and resulted in the formation of a dispersed two-phase NbSS and β-Nb5(Si, Al)3 structure in the alloy.The increased volume fraction of NbSS and the dispersed structure formed after electric arc remelting in thealloy increase its fracture toughness to 14.8 ± 0.8 MPa m1/2 compared to 7.7 ± 0.8 MPa m1/2 for the SHSpreparedalloy.
The Critical Temperature of Superconducting Aluminum Films
Authors: Arutyunov K. Yu. , Sedov E. A. , Zavialov V. V. , Stavrinidis A. , Stavrinidis G. , Chatzopoulos Z. , Adikimenakis A. , Konstantinidis G. , Florini N. , Chatzopoulou P. , Kehagias T. , Dimitrakopulos G. P. , Komninou F.
Published: April 2024

The R(T) dependences of thin superconducting aluminum films deposited on leucosapphire and gallium arsenide substrates by electron beam sputtering and molecular beam epitaxy have been experimen-tally studied. Regardless of morphology, a noticeable increase in the critical temperature of the supercon-ducting transition with a decrease in the film thickness is found. The effect is interpreted as a manifestation of the quantum size effect.
Grain-Boundary Diffusion of 57Сo in Niobium
Authors: Popov V. V. , Istomina A. Yu. , Osinnikov E. V. , Falakhutdinov R. M.
Published: April 2024

The grain-boundary diffusion of Co in Nb has been studied by a layer-by-layer radiometric analysis in the temperature range of 723–873 K. The diffusion annealing modes corresponded to the kinetic C mode, which implies that the diffusion proceeds only along grain boundaries. The coefficients of grain-boundary diffusion of Co in Nb have been determined for several temperatures from diffusion profiles. An expression for the Arrhenius dependence of Co diffusion coefficient along the grain boundaries of Nb has been determined. The temperature dependence of coefficient of grain-boundary segregation of Co in Nb is constructedbased on the temperature dependence of coefficient of grain-boundary diffusion of Co in Nb and the data in the literature on the temperature dependence of the triple product.
The Chiral Spin-Orbitronics
of a Helimagnet–Normal Metal Heterojunction
Authors: Ustinov V. V. , Yasyulevich I. A. , Bebenin N. G.
Published: April 2024

A theory of spin and charge transport in bounded metallic magnets has been constructed, which takes into account the effects of spin-orbit scattering of conduction electrons by crystal lattice defects. The theory can be used to describe the spin Hall effect and the anomalous Hall effect and can serve as a basis for describing the phenomena of spin-orbitronics. Phenomenological boundary conditions for the charge and spin fluxes at the interface between two different metals have been formulated, on the basis of which the injec-tion of a pure spin current into a helimagnet, which arises in a normal metal as a manifestation of the spin Hall effect, is described. The existence of an “effect of chiral polarization of a pure spin current” is predicted, which consists in the appearance in a helimagnet of a longitudinally polarized pure spin current and a longi-tudinal component of the nonequilibrium electron magnetization, depending on the chirality of the helimag-net helix, upon injection of a transversely polarized spin current from a normal metal.
The Creation of Complex Multi-Component Models
of Mössbauer Spectra Based on the Example of a Study of Hyperfine Interactions in Quasi-Binary Alloys
with the Laves Phase Structure
Authors: Matsnev M. E. , Rusakov V. S.
Published: April 2024

In this paper, we describe a method for creating new custom models of partial Mössbauer spectrabased on the existing ones built into the SpectrRelax program without changing the program itself by writing code fragments in the built-in Lua programming language. The extension of the capabilities of the SpectrRelaxprogram is demonstrated using the example of studying hyperfine interactions of 57Fe nuclei in quasibinary Tb(Fe0.8Al0.2)2 and Ho(Fe0.8Mn0.2)2 alloys with the C15 Laves phase structure. A model for processingthe spectra, which simultaneously takes the composite and magnetic nonequivalence of the positions of Fe atoms in these alloys, has been created and used, which makes it possible to obtain new data about the orientationof the axis of the easiest magnetization, the anisotropy of the hyperfine magnetic field, and the effect of substitution of Al and Mn atoms for Fe atoms on hyperfine parameters of Mössbauer spectra.
Influence of cold deformation on the structure, texture, elastic and microdurometric properties of biocompatible beta-titanium alloys based on the Ti–Nb–Zr system
Authors: Korenev A. A. , Illarionov A. G.
Published: April 2024

The influence of cold rolling with degrees of 85, 90% on the structural and textural state, microdurometric and elastic properties of hardened biocompatible -titanium alloys (at.%) Ti-26%Nb-3%Zr, Ti -26%Nb-5%Zr, Ti-26%Nb-6%Zr, Ti-26%Nb-3%Zr-1%Sn, Ti-26%Nb-3%Zr-1%Sn-0.7Ta . It is shown that an increase in the degree of deformation during cold rolling contributes to the formation of a more pronounced two-component texture {001}, {112} an increase in microhardness and a decrease in the values ​​of the elastic modulus in the rolling plane . A good agreement between the calculated and experimental values ​​of the modulus of elasticity of alloys in the quenched and cold-rolled states has been established.The influence of alloying and anisotropic state of alloys (through the molybdenum equivalent and the Zener anisotropy factor, respectively) on the level of their microhardness, contact modulus of elasticity E, including the difference in E in different sections of a cold-rolled sheet, is considered. It has been established that the minimum average value of Е=51±2 GPa in the rolling plane is given by the Ti-26Nb-3Zr alloy rolled with ε=90%, and the minimum level of average values Е (52±2 GPa in the rolling plane and 62±1 GPa in cross section) is typical for the Ti-26Nb-3Zr-1Sn alloy after rolling with ε= 85%
The Effect of Torsional Stresses on the Giant Magnetoimpedance
of Amorphous Microwires with Induced Magnetic Anisotropy
Authors: Buznikov N. A.
Published: April 2024

The paper presents a theoretical study of the effect of torsional stresses on the giant magnetoimpedance of a Fe-rich amorphous microwire with helicoidal anisotropy induced in the surface layer as a result of annealing. It is shown that torsional stresses lead to a change in the shape of the dependence of the impedance of the microwire on an external field at relatively low frequencies of the excitation current. Thechange in impedance is maximal near the stress value at which an effective circular anisotropy in the surface region of the microwire appears. The results can be used to create stress and weak magnetic field sensors.
Structure of a Cast Al2Au Intermetallic Compound with an Additive of Cu
Authors: Volkova E. G. , Antonov B. D. , Zavalishin V. A. , Knyazev Yu. V. , Gavrilova A. A. , Volkov A. Yu.
Published: April 2024

To produce an Al2Au+Cu ingot, a mixture of Al2Au and copper intermetallic powders was compacted and then melted in an argon atmosphere. The study of the ingot structure revealed the formation of brightly colored regions of the intermetallic phase Al2Au, which are located in a matrix of intermetallic AlAu. Thin veins enriched with copper were found inside the AlAu matrix. The optical characteristics of the resulting triple compound were measured. Microindentation of intermetallic phases was carried out, the values of their microhardness and contact modulus of elasticity were determined
Evolution of the structure, texture and mechanical properties of a cold-swaged austenitic stainless steel during post-deformation annealing
Authors: Chernichenko R. S. , Panov D. O. , Naumov S. V. , Kudryavtsev E. A. , Mirontsov V. V. , Salishchev G. A. , Pertsev A. S.
Published: April 2024

In this work, we studied the effect of annealing temperature on the structure and texture, as well as the mechanical properties of the austenitic stainless steel AISI 316. Initially, the program material was subjected to cold rotary swaging with a reduction of 95%. Studies showed the formation of the structure and texture gradient during preliminary plastic deformation. Annealing at low temperatures (500-600°C) provoked polygonization, while the intensity of the and texture components remained unchanged. After annealing at 700°С, the onset of recrystallization was observed only in the subsurface layers of the rod. As a result of annealing at 800–900°C, static recrystallization occurred over the entire cross section of the rod, which caused dissipation of the texture gradient. Annealing at temperatures of 400–600°C was accompanied by an increase in the strength and hardness characteristics. Meanwhile, ductility also increased with the annealing temperature. Annealing at 700°C resulted in softening of the program material almost to the level of the initial cold-swaged state and a significant increase in ductility up to 16%.
Effect of Mechanical Activation Time on the Density of Fine-Grained Tungsten Alloy 90W–7Ni–3Fe, Obtained by Spark Plasma Sintering
Authors: Chuvil’deev V. N. , Nokhrin A. V. , Boldin M. S. , Lantsev E. A. , Sakharov N. V.
Published: April 2024

Abstract—The influence of the high-energy mechanical activation (HMA) time on the kinetics of solid-phase Spark Plasma Sintering (SPS) and the microstructure of a heavy tungsten alloy 90W–7Ni–3Fe has been studied. The density of the alloy 90W–7Ni–3Fe nonmonotonically, with a minimum, depends on the time of the HMA. The kinetics of the SPS of nanopowders has a two-stage character; the sintering intensity depends on the rate of Coble creep and the intensity of diffusion of W atoms in the crystal lattice of the nickel-based gama-phase.
NONLINEAR EFFECTS IN CRYSTALLINE SOLIDS WITH SATURATION OF AMPLITUDE-DEPENDENT INTERNAL FRICTION, DECREASING WITH IN-CREASING FREQUENCY
Authors: Nazarov V. E. , Kiyashko S. B.
Published: April 2024

As a result of modification of quasi-static elastic and inelastic hysteresis, dynamic hysteresis equations of state of crystalline solids with frequency-dependent saturation of amplitude-dependent internal friction decreasing with increasing frequency are proposed. The nonlinear propagation of initially harmonic longitudinal elastic waves in rods made of such materials is investigated by the perturbation method. Numerical, graphical and comparative analysis of the obtained solutions is carried out and characteristic amplitude-frequency dependenc-es of nonlinear wave effects are revealed. A method for determining the type of dynamic hysteresis for crystal-line solids with frequency-dependent saturation of amplitude-dependent internal friction is proposed.
Magnetic Phase Transitions in Ultrathin YFeO3 Films According
to Synchrotron Mössbauer Reflectometry Data
Authors: Izyurov V. V. , Nosov A. P. , Gribov I. V. , Andreeva M. A.
Published: April 2024

The magnetic properties of ultrathin single-crystal Y57FeO3 orthoferrite films have been studied by Mössbauer reflectometry. Mössbauer spectra were measured using the ESRF synchrotron in the reflection geometry. As the temperature changes from 3.6 K to about 773 K, the splitting of the Zeeman sextet in the spectra successively decreases and, simultaneously, a quadrupole doublet appears in them, which indicates the development of a magnetic phase transition. From the temperature dependences of the magnetic hyperfine field Bhf for the main orthorhombic Y57FeO3 phase, Néel temperatures equal to TN ≈ 593 K, 562 K, and 567 K and the critical parameter values equal to β ≈ (0.28–0.3) ± 0.02 are determined in films with thicknesses of 28, 6.5, and 4 nm, respectively. An analysis of changing the ratio of the line intensities in the Zeeman sextet with temperature makes it possible to trace the successive rotation of the direction of the antiferromagnetic axes in Y57FeO3 toward the surface plane with an increase in the temperature and a decrease in the film thickness.
The Structure and Mechanical Properties of Rolled Sheets
of the Multicomponent Al–2.5Ca–2.5Mg Alloy Doped with Scandium and Zirconium
Authors: Doroshenko V. V. , Naumova E. A. , Aksenov A. A. , Shcherbakova O. O. , Finogeev A. S.
Published: April 2024

Using the Al–2.5% Mg–1% Mn–0.4% Fe base alloy (wt %) as an example, the effects of calcium, scandium, and zirconium additives (at about 2.5, 0.1, and 0.2 wt %, respectively) on the strength of rolled sheets has been studied. Ingots of the alloy of the chosen composition and the hot and cold rolled sheets obtained from them were used as objects for the experimental study. Based on microstructural studies, it isshown that calcium binds iron into compact inclusions (presumably, into the Al10CaFe2 phases), which has a positive effect on the mechanical properties of the alloy, as well as on the technological plasticity during therolling operation. Zirconium and scandium additives make it possible to form thermally stable nanoparticles of the Al3(Zr, Sc)–L12 phase, which is favorable for maintaining a partially unrecrystallized structure in coldrolled sheets during annealing at least up to 400°C. Using the alloy of the selected composition as an example, the fundamental possibility for producing sheet products from cast (unhomogenized) ingots with the properties of thermally hardenable alloys of the AlSiMgMn and AlZn4.5Mg1.5Mn types without using quenching has been demonstrated.
EFFECT OF HIGH PRESSURE TORSION ON STRUCTURE AND MECHANICAL PROPERTIES OF Al–Ca–Cu ALLOY
Authors: Rogachev S. O. , Naumova E. A. , Tabachkova N. Yu. , Ten D. V. , Sundeev R. V. , Zadorozhny M. Yu.
Published: April 2024

To improve the balance of strength and ductility of the Al–6% Ca–8% Cu (wt %) alloy, the high-pressure torsion (HPT) deformation followed by annealing was applied. The structure of the as-cast alloy consisted mainly of two eutectics [(Al) + AlCaCu] and [(Al) + (Al, Cu)4Ca + AlCaCu]. HPT through three turns leads to the formation of a predominantly submicrocrystalline structure, refinement of eutectic particles and their more uniform distribution in the sample volume, calcium segregation from AlCuCa and (Al, Cu)4Ca particles, and supersaturation of the (Al) solid solution with copper. Such a structure provides a strengthening of the alloy by a factor of 3.5, but contributes to its embrittlement. Subsequent annealing at 400°C achieves a good balance of strength and ductility of the alloy.
A Study of Residual Stresses in Steel Plates Obtained
by Laser Deposition Directly on a Rigid Substrate
Authors: Rylov S. A. , Ivanov S. Yu. , Zemlyakov E. V. , Babkin K. D. , Karpov I. D. , Em V. T.
Published: April 2024

A neutron diffraction method has been used to study residual stresses in corrosion-resistant martensitic steel AISI 410 plates of the composition (wt %): 0.15 С, 13 Cr, 1 Mn, 1 Si, and Fe for balance obtained by direct laser deposition. The plates are deposited on rigid substrates, which are commonly used in practice in the production of large parts. It has been shown that in plates of different thicknesses (2.2 and 7.4 mm) and the same length and width (70 × 30 mm), the patterns of the stress distribution curves are very close, however, the stresses in a 7.4-mm-thick plate are lower than in a 2.2-mm-thick plate. In both plates (2.2/7.4 mm), the maximum normal tensile stresses (~450/350 MPa) are induced near lateral edges of the substrate. The maximum tensile longitudinal stresses (~400/250 MPa) are induced in the middle section of the plate near the upper edge. In the middle section of a 7.4-mm-thick plate, a stress distribution over the thickness is observed: the stresses near the side surfaces are higher than in the middle section. The thickness distribution becomes more uniform by approaching the plate edges. The stress distribution pattern in plates obtained by direct laser deposition strongly depends on the rigidity of the substrate and, to a lesser extent, on the material and deposition technology.
The Electronic Structure and Optical Spectroscopy
of ErNi2Mnx Compounds
Authors: Knyazev Yu. V. , Lukoyanov A. V. , Kuz’min Yu. I. , Gerasimov E. G. , Mushnikov N. V.
Published: April 2024

The electronic structure and optical properties of nonstoichiometric ErNi2Mnx compounds (with х = 0, 0.5, 1) have been studied. Spin-polarization calculations of the total and partial densities of electron states have been performed in terms of DFT + U method with a correction for strong electronic correlations in the 4f shell of Er in the approximation of ErNi2 – xMnx solid-solution. The peculiarities of transformations of the densities of electron states Have been determined depending on the manganese content. The optical properties of these compounds have been studied over a wide wave length range. The calculated interband optical conductivity spectra have been compared with the dependences obtained experimentally. The origin of the quantum absorption of light is discussed. The plasma and relaxation frequencies of current carriers have been determined.
MD Simulations of Collision Cascades in α-Ti. Statistics and Governing Mechanisms of Point Defect Cluster Formation
Authors: Voskoboynikov R. E.
Published: April 2024

The outcomes of molecular dynamics simulations of primary damage formation in collision cascades initiated by primary knock-on atoms (PKA) with PKA energy 5 keV ≤Epka≤ 25 keV in α-titanium at 100 K ≤T≤ 900 K temperatures have been analysed. The fraction of vacancies, εv, and self-interstitial atoms (SIA), εi, in point defect clusters created in isolated collision cascades was evaluated. The corresponding averages ⟨εv⟩ and ⟨εi⟩ over cascade series with the same (Epka, T) parameters, the average size ⟨Nvac⟩ and ⟨Nsia⟩ of vacancy and SIA clusters, respectively, and the average vacancy ⟨Yvac ⟩ and SIA ⟨Ysia ⟩ cluster-per-cascade yield were found as well. Possible governing mechanisms have been suggested to explain ⟨εv⟩, ⟨εi⟩ , ⟨Nvac⟩, ⟨Nsia⟩, ⟨Yvac⟩ and ⟨Ysia⟩ dependence on (Epka,T).
A systematic description of the thermodynamic, elastic and mechanical properties of binary Zr-based bcc alloys from first principles
Authors: Smirnova E. A. , Ponomareva A. V. , Konov D. A. , Belov M. P.
Published: April 2024

The effects of the dissolution of 3d, 4d, and 5d metals, as well as Al, In, and Sn in the bcc lattice of Zr, were studied within the framework of the electron density functional theory. Using the EMTO-CPA method, we calculated the lattice parameters, enthalpies of mixing, single-crystal elastic constants C11, C12, C44, and C', polycrystalline elastic moduli E, G, and plasticity characteristics of disordered Zr-based bcc alloys over a wide concentration range. The PAW-SQS method was used to study the effects of alloying on the specified properties of bcc Zr-X alloys, where X is a series of 4d elements Nb, Mo, Tc, Ru, Rh and 5d elements Ta, W, Re, Os, Ir for concentration cuts 6.25, 25 and 50 at.%. The analysis of concentration and periodic dependences of properties of alloys, their stability is carried out.
NOVEL FUNCTIONAL MATERIALS BASED ON AMORPHOUS ALLOYS OF Fe–Сo–Сr SYSTEM
Authors: Zanaeva E. N. , Bazlov A. I. , Ubyivovk E. V. , Milkova D. A.
Published: April 2024

The work is devoted to the study of the possibility of obtaining hard magnetic materials during the crystalli-zation of amorphous alloys of the Fe–Co–Cr–B–Si system. The influence of boron content in alloys on their glass-forming ability was analyzed. The structure and phase transformations in alloys during heating were ana-lyzed using X-ray diffraction and transmission electron microscopy. Influence of the phase composition on the magnetic properties of the alloys has been established. It is shown that the formation of a nanosized eutectic structure [α + (Fe, Cr)3B] during the crystallization of an amorphous matrix is promising for development of new hard magnetic materials.
Atomistic Simulation of Plastic Deformation in Two-Phase Al/θ' Bicrystals Saturated with Hydrogen
Authors: Bezborodova P. A. , Krasnikov V. S. , Mayer A. E.
Published: April 2024

In this work we investigate the effect of hydrogen atoms on the deformation behavior of Al/θ′ bicrystals with (001)Al//(001)θ′ interfacial boundary by the molecular dynamics method.
Magneto-impedance tomography of CoFeTaSiB amorphous wires
Authors: Bukreev D. A. , Derevyanko M. S. , Moiseev A. A. , Semirov A. V.
Published: April 2024

The paper presents the results of a study of the radial distribution of the magnetic permeability of an Co66Fe4Ta2.5Si12.5B15 amorphous wire with a radius of 55 μm. The study was performed using magneto-impedance tomography in the frequency range of alternating current from 0.01 to 100 MHz. It was found that the magnetic permeability significantly depends on the radial coordinate. Wherein the inner regions of the wire have predominantly axial anisotropy, while the outer layer about 2.5 µm thick has circular anisotropy. It is shown that the magnetoelastic mechanism is not the main one in the formation of magnetic anisotropy in the surface layer of the wire.
Anomalous Magnetic Viscosity in (Sm,Zr)Fe11Ti Alloys with ThMn12-Type Structure
Authors: Neznakhin D. S. , Volegov A. S. , Maltseva V. E. , Andreev S. V.
Published: April 2024

Abstract—Magnetic properties of the microcrystalline Sm1 – xZrxFe11Ti (x = 0, 0.1, 0.2) alloys with ThMn12-type structure were investigated. Irreversible jumps of magnetization on major hysteresis loops at low temperatures (2–4 K) were found. The jumps are random either in the magnitude of the magnetic field in which they occur or in their amplitude, and are independent of the chemical composition. There is a specific annealing temperature for each alloy, above which magnetization jumps are not observed in annealed alloys at low temperatures. The magnetic viscosity of Sm0.9Zr0.1Fe11Ti alloy annealed at 700°C was investigated at temperatures of 2–4 K. The magnetic viscosity coefficient has a discontinuity in the field of magnetization jump. This behavior is explained by thermal processes occurring during magnetization of the alloy through the magnetization jump.
Simulation of the atomic structure near spherical void in aluminum and the calculation of the anisotropy of the void growth rate
Authors: Nazarov A. V. , Melnikov A. P. , Mikheev A. A.
Published: April 2024

We simulate structure in the vicinity of different size nanovoids using a new variant of the Molecular Statics, wherein atomic structure in the vicinity of nanovoids and the parameters that define the displacements of atoms placed in elastic continuum around main computation cell are determined in a self-consistent manner. Then, the previously obtained kinetic equations are applied to calculate the shifting rate of the elements of the void surface in certain crystallographic directions. These equations take into account the dependence of the vacancy flux on the deformation fields. The displacement rates in different crystallographic directions for bcc and fcc metals are significantly different. The results show that the effects studied by computer simulation can lead to a change in the shape of initially spherical nanopores and cause their transformation into cuboidal pores in metals with a cubic structure under irradiation.
Structure, Phase Composition and Mechanical Properties of a High-Strength Steel with Transition Carbide η-Fe2C
Authors: Borisova Yu. I. , Mishnev R. V. , Tkachev E. S. , Kniaziuk T. V. , Gaidar S. M. , Kaibyshev R. O.
Published: April 2024

Abstract—The influence of quenching and tempering on the structure, phase composition and mechanical properties of high-strength Fe–0.34 C steel with 1.77 wt % Si is considered. The tempering at temperatures up to 500°C has virtually no effect on the structural characteristics of packet martensite formed during quenching. At tempering temperatures in the range of 200–400°C, the precipitation of transition η-carbide occurs, which leads to an increase in the yield strength to 1490 MPa and impact toughness to 35 J/cm2. The determined temperature of the brittle-ductile transition after tempering at 200°C is about –50°C. A decrease in the impact toughness and a decrease in the proportion of ductile fracture with a decrease in the test temperature is accompanied by a transition from transgranular to intergranular fracture. The precipitation of cementite particles along the boundaries of laths and blocks is observed after tempering at 500°C. This leads to a decrease in the yield strength, while the impact toughness of the steel remains unchanged.
Influence of High Content of Sodium Doping in Bi(Pb)2212 Superconductors
Authors: Bouaïcha F. , Mosbah M. F. , Ozyuzer L.
Published: April 2024

We study here, the effect of high content of sodium doping on structural and electrical properties of Bi(Pb)2212 superconducting. The X-ray analysis results showed that all the prepared samples mainly belong to the superconducting tetragonal phase Bi–(Pb)2212. SEM micrographs show that the grains are closely related and have a characteristic flat shape for the superconductor Bi (Pb) 2212. For the undoped sample, the grains are randomly distributed with an average size of 5 μm. For doped samples, the morphology changes with sodium concentration. Resistivity measurements show that all samples have a superconducting character.
Interlayer Interaction and Coercivity of Three-Layer Films Оbtained bу Chemical Deposition
Authors: Chzhan A. V. , Orlova V. A. , Volochaev M. N.
Published: April 2024

Abstract—The results of experimental and theoretical studies of the coercivity and the displacement field of the hysteresis loop on the thickness of the nonmagnetic interlayer in magnetic films obtained by electroless plating are presented. With the help of model calculations based on the Landau–Ginzburg equations, the exchange interactions between magnetic layers with the participation of atoms of the nonmagnetic layer are studied. The resulting expression for the displacement field describes well the exponential changes in the displacement field as a function of the interlayer thickness in structures with both magnetically soft layers and layers with significantly different values of the coercivity.
Magnetization and Magnetostriction of LaFe11.2 – хMnxCo0.7Si1.1 (x = 0.1, 0.2, 0.3) Alloys In Pulsed Magnetic Fields
Authors: Abdulkadirova N. Z. , Gamzatov A. G. , Batdalov A. B. , Kamilov K. I. , Aliev A. M. , Gebara P.
Published: April 2024

Abstract—The magnetization and magnetostriction of polycrystalline alloys LaFe11.2 – хMnxCo0.7Si1.1 (x = = 0.1, 0.2, 0.3) were measured in pulsed magnetic fields up to 180 kOe in the temperature range 80–270 K. The replacement of Fe atoms by Mn atoms shifts the TC towards low temperatures and does not affect the value of saturation magnetization. The observed field dependence of the magnetization M(H) near the TC is characteristic of second-order phase transitions, while the temperature dependence of the magnetization M(T) above the TC in strong magnetic fields indicates a first-order magnetic phase transition. The magnetic volume effect ΔV/V reaches 0.81% in a field of 180 kOe. The asymmetry of magnetostriction relative to the temperature of the maximum effect, manifested in strong magnetic fields, and the magnetic field hysteresis of magnetostriction bear signs of a first-order phase transition