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ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

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Tilda Publishing

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Peculiarities of modern powder-metallurgy technology for manufacturing
of (Nd, R) – Fe – B (R = Pr, Ce, Dy, Tb, Ho) sintered permanent magnets

N. A. Dormidontov, P. A. Prokofev, N. B. Kolchugina, M. V. Zheleznyi,
A. S. Bakulina, D. A. Rusinov

Sintered Nd–Fe–B-based magnets, which play a key role in enhancing the efficiency of electromechanical energy conversion and the operational reliability of wind turbines and electric vehicle drive systems, are valued for their high coercivity, substantial remanence, and highest maximum energy product. The hysteresis characteristics of sintered permanent magnets are structure-sensitive parameters. This fact establishes both the possibility and the necessity of purposeful engineering the microstructure of Nd–Fe–B permanent magnets to improve or modify their properties. The main obstacle to developing cost-effective and high-performance magnets of this type is the trade-off between coercivity and remanence, coupled with a serious imbalance in the need to utilize scarce rare-earth metals. This review examines the grain boundary diffusion, which is implemented from diffusion sources during the manufacturing process of sintered permanent magnets and enables resource-efficient use of rare-earth metals. The diffusion effect is associated with the modification of (1) the structure and composition of grain boundaries through creating a continuous grain-boundary phase that enhances magnetic isolation between grains and reduces the probability of reverse-domain nucleation during magnetization reversal, and (2) the structure and composition of the main magnetic-phase grains (based on the Nd2Fe14B compound), resulting in a “core-shell” grain structure with a non-uniform distribution of rare-earth metal components. The stages of development of grain-boundary diffusion processes are considered, including “magrise” and “in situ” processes, as well as three generations of diffusion-source compounds (heavy rare-earth metals, light rare-earth metals, and rare-earth-free materials), including those for magnets in which cerium and lanthanum substitute for neodymium (or praseodymium) and recycled magnets. Powder metallurgy technology utilizing the grain-boundary diffusion can rightfully be defined as a revolutionary technology for Nd-Fe-B permanent magnets.

Key words: Nd – Fe – B permanent magnets, heavy rare-earth metals, coercive force, grain-boundary diffusion, core-shell structure, magnet-to-magnet recycling.

DOI: 10.30791/1028-978X-2026-10-5-28

Reference citing:
Dormidontov N.A., Prokofev P.A., Kolchugina N.B., Zheleznyi M.V., Bakulina A.S., Rusinov D.A. Osobennosti sovremennoj tekhnologii izgotovleniya spechennyh postoyannyh magnitov (Nd, R)-Fe-B (R = Pr, Ce, Dy, Tb, Ho) metodami poroshkovoj metallurgii [Peculiarities of modern powder-metallurgy technology for manufacturing of (Nd, R) – Fe – B (R = Pr, Ce, Dy, Tb, Ho) sintered permanent magnets]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 10, pp. 5 – 28

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Low-temperature relaxation processes in thin layers
of a polymer composite with a ferroelectric filler

R. A. Castro, E. A. Karulina, S. V. Senkevich

The regularities of polarization processes in dielectric composite films of low-density polyethylene with a ferroelectric filler of barium titanate have been established: the dependence of AC conductivity and dielectric losses on frequency and temperature. It is shown that charge transfer in this system can be described from the standpoint of the theory of hopping conductivity in non-ordered systems. A monotonic (exponential) increase in the dielectric constant with temperature and a non-Debye character of the loss coefficient dependence have been established. The existence of an asymmetric distribution of relaxators according to their relaxation times in the low-temperature region has been noted.

Keywords: electrophysical properties, polarization processes, polymer composites, dielectric characteristics, and hopping conductivity.

DOI: 10.30791/1028-978X-2026-10-29-36

Reference citing:
Castro R.A., Karulina E.A., Senkevich S.V. Nizkotemperaturnye relaksacionnye processy v tonkih sloyah polimernogo kompozita s segnetoelektricheskim napolnitelem [Low-temperature relaxation processes in thin layers of a polymer composite with a ferroelectric filler]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 10, pp. 29 – 36.

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Peculiarities of high-power pulsed laser radiation interaction
with fusion reactor vacuum chamber materials

I. V. Borovitskaya, V. N. Pimenov, S. N. Korshunov, A. N. Mansurova,
S. A. Maslyaev, S. V. Latyshev, G. G. Bondarenko, S. V. Simakov,
N. A. Vinogradova, A. I. Gaidar, E. V. Matveev

Comparison, generalization, and systematization of the erosion and destruction mechanisms of the surface of low- activation materials promising for use as the fusion reactor vacuum chamber materials of: vanadium, its alloy V – 10 Ti – 6 Cr – 0.05 Zr – 0.1 Si and tungsten under the sequential action of ion and heat fluxes has been fulfilled. Heat fluxes were simulated using high-power pulsed laser radiation (LR) generated in the GOS 1001 installation in the modulated Q mode with a flux power density of 1·1012 W/m2 and 1·1014 W/m2, pulse duration t = 50 ns, number of pulses N from 1 to 8. The samples were irradiated as in the initial state, and after implantation by helium ions (energy – 30 keV, dose 1.0·1022 cm–2 and 2.0·1023 cm–2) and argon ions (energy – 20 keV, dose 1.0·1022 cm–2 and 2.0·1022 cm–2), which was carried out in the ion beam accelerator (ILU). It is established that the nature of the samples destruction depends on the target material and, according to the results of numerical modeling, is associated with the redistribution of laser beam energy between the melting and evaporation processes for a specific combination: LR power density – implanted ion – irradiated material. It is shown that exposure to high–power laser pulses leads to the change in the morphology and to the increase in surface erosion at all stages of interaction with materials due to the generation of evaporation and melting processes, the formation and destruction of blister - bubbles, as well as the appearance of cracks. These results of simulation experiments show that in real reactor operating conditions, pulsed radiation and thermal effects can contribute to plasma contamination and reduce reactor life. It was found that the characteristic features of surface damage and destruction under the LR influence for all studied materials are most noticeably manifested on samples previously irradiated with gas ions, that is, as a result of a synergistic effect.

Keywords: pulsed laser radiation, ion implantation, helium and argon ions, tungsten, vanadium, vanadium alloy, surface damage, erosion, evaporation, melting, blisters.

DOI: 10.30791/1028-978X-2026-10-37-54

Reference citing:
Borovitskaya I.V., Pimenov V.N., Korshunov S.N., Mansurova A.N., Maslyaev S.A., Latyshev S.V., Bondarenko G.G., Simakov S.V., Vinogradova N.A., Gaidar A.I., Matveev E.V. Osobennosti vzaimodejstviya moshchnogo impul'snogo lazernogo izlucheniya s materialami vakuumnoj kamery termoyadernogo reaktora [Peculiarities of high-power pulsed laser radiation interaction with fusion reactor vacuum chamber materials]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 10, pp. 37 – 54

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Investigation of the crystallization process in multielement systems based on 45S5 bioactive glass

N. V. Leontiev, D. D. Pogolskaya, D. S. Larionov, D. O. Golubchikov, Ya. Yu. Filippov,
E. S. Klimashina, A. M. Murashko, P. V. Evdokimov, V. I. Putlayev

The results of the synthesis of multicomponent glasses based on the base composition of Bioglass 45S5 are presented, which was modified by introducing up to 20 chemical elements to impart osteoinductive properties to the material. The multicomponent chemical composition of the glasses is determined by the specific role of each element in the biochemical processes accompanying the natural process of bone remodeling. An analysis of the glass transition and crystallization processes of the modified glasses was carried out, and the stable and metastable phases formed depending on the composition were established. The operating temperature range for softened glass becomes narrower for multielement glasses and shifts to a lower temperature range, which is naturally associated with a greater fragmentation of the silicon‑oxygen network in the modified glasses. An analysis of the sintering of glass powders indicates a two‑stage shrinkage process, with the first stage attributed to the transition of the glass to a viscous flow state, and the second stage to phase separation and the onset of crystallization. The obtained results demonstrate that multicomponent glasses can serve as a basis for the development of osteoinductive glass‑ceramic materials suitable for the fabrication of three‑dimensional porous scaffolds in bone tissue engineering.

Keywords: bioglass, osteoinductive implant, high-entropy phases, glass transition, crystallization, glass-ceramics

DOI: 10.30791/1028-978X-2026-10-55-69

Reference citing:
Leontiev N.V., Pogolskaya D.D., Larionov D.S., Golubchikov D.O., Filippov Ya.Yu., Klimashina E.S., Murashko A.M., Evdokimov P.V., Putlayev V.I. Issledovanie processa kristallizacii mnogoelementnyh sistem na osnove bioaktivnogo stekla 45S5 [Investigation of the crystallization process in multielement systems based on 45S5 bioactive glass]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 10, pp. 55 – 69.

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Investigation of the composition and structure of titanium alloys after exposure to a stream of low-energy ions generated from a low-pressure RFI plasma

I. Sh. Abdullin, K. Sh. Mastyukov, S. V. Mironov

Studies of samples from the VT-8 material have been carried out on an RF plasma installation. The samples were processed in a stream of low-energy ions (low-energy ions) generated from a low-pressure RF plasma using pure argon and a mixture with nitrogen and oxygen as a plasma-forming gas under different conditions: the discharge power, gas flow, and distance from the plasma torch section to the body were varied. The change in the roughness and chemical composition of the surface of materials after RF plasma treatment is investigated. The surface roughness decreases from 0.64 – 0.32 microns to 0.16 – 0.08 µm.

Keywords: RF plasma, reduced pressure, roughness, X-ray spectral analysis, titanium alloy.

DOI: 10.30791/1028-978X-2026-10-70-76

Reference citing:
Abdullin I.Sh., Mastyukov K.Sh., Mironov S.V. Issledovanie sostava i struktury titanovyh splavov posle vozdejstviya potoka nizkoenergeticheskih ionov, generiruemyh iz VCHI plazmy ponizhennogo davleniya [Investigation of the composition and structure of titanium alloys after exposure to a stream of low-energy ions generated from a low-pressure RFI plasma]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 10, pp. 70 – 76.

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Finite element modeling of equivalent stress-strain curves obtained by indentation
of thin coatings with a microspherical tip

S. A. Votyakov, S. I. Votyakova, G. Kh. Sultanova, A. S. Useinov

The paper proposes an approach to construct corrected stress-strain curves for the indentation of metal coatings using a microspherical tip. The case of a 3.4 μm thick silver film on a silicon substrate (a soft film on a hard substrate) is considered, using a diamond spherical tip with a nominal radius of 2.5 μm. Experimental loading-unloading (P-h) curves were converted into stress-strain curves using Tabor’s equations. It is shown that when an ideal spherical geometry is used for the conversion of stress-strain diagrams, the graphs deviate significantly from the expected shape. To obtain the true shape of the diagrams, the deviation of the indenter profile from the ideal one is taken into account, and a correction function for the indenter contact area based on two saturating exponentials is introduced. An axisymmetric finite element (FE) model was built in the COMSOL Multiphysics software package for a diamond indenter of real geometry, specifying parameters for silver and silicon close to the experimental ones. Based on the von Mises stress and equivalent plastic strain fields, model diagrams comparable to the experimental stress-strain curves were obtained. It is established that accounting for the contact area correction function used in building the model significantly improves the agreement between experimental and model dependencies. The inverse transformation of the model curve via the same correction function reproduces the shape of the original experimental diagram plotted without correction. The results demonstrate that even a slight deviation of the microspherical indenter from the ideal spherical shape significantly distorts the calculated mechanical characteristics.

Keywords: microspherical indenter, thin films, stress-strain curve, Tabor’s equations, effective contact area, Voce law, von Mises stress, finite element modeling, COMSOL Multiphysics.

DOI: 10.30791/1028-978X-2026-10-77-87

Reference citing:
Votyakov S.A., Votyakova S.I., Sultanova G.Kh., Useinov A.S. Konechno-elementnoe modelirovanie ekvivalentnyh diagramm “napryazhenie – deformaciya”, poluchaemyh pri indentirovanii tonkih pokrytij mikrosfericheskim nakonechnikom [Finite element modeling of equivalent stress-strain curves obtained by indentation of thin coatings with a microspherical tip]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 10, pp. 77 – 85