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Tilda Publishing

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Regulating sulfur concentration in molybdenum sulfide layers to boost the tribological properties of nanolayered a-MoSx/a-C coatings

S. N. Grigoriev, D. V. Fominski, V. N. Nevolin, I. V. Suminov, M. D. Gritskevich, V. Yu. Fominski

Using a combined vacuum and reactive pulsed laser deposition method, multilayer coatings consisting of alternating layers of amorphous molybdenum sulfide (a-MoSx) and diamond-like carbon (a-C) were created. The atomic concentration ratio x = S/Mo in the molybdenum sulfide layers was ~ 2 and 3, respectively, and the layer thickness did not exceed 12 nm. The tribological properties of the coatings were studied using a steel ball sliding on a disk under challenging conditions. The modification of coatings by tribo-impact was studied using micro-Raman spectroscopy. A significant effect of the chemical composition of molybdenum sulfide layers on the friction coefficient and wear resistance of the coatings was established at room testing temperature. Increasing the sulfur concentration ensured a prolonged solid lubricant effect in both humid air (friction coefficient of 0.1 – 0.2) and argon (friction coefficient of 0.015) due to the formation of a tribofilm containing a composition of 2H-MoS2 and a-C(S) nanophases. When the tribo-testing temperature in argon was reduced to –100 °C, good antifriction properties were maintained, but the differences in properties of these coatings were less pronounced.

Keywords: multilayer coatings, diamond-like carbon, molybdenum sulfides, sulfur concentration, solid lubricants, pulsed laser deposition, nanostructure, micro-Raman spectroscopy.

DOI: 10.30791/1028-978X-2026-5-5-18

Reference citing:
Grigoriev S.N., Fominski D.V., Nevolin V.N., Suminov I.V., Gritskevich M. D., Fominski V.Yu. Regulirovanie koncentracii sery v sloyah sul'fida molibdena dlya kachestvennogo uluchsheniya tribologicheskih svojstv nanoslojnyh pokrytij a-MoSx/a-C [Regulating sulfur concentration in molybdenum sulfide layers to boost the tribological properties of nanolayered a-MoS_x/a-C coatings]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 5, pp. 5 – 18. DOI: 10.30791/1028-978X-2026-5-5-18

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Study of the effect of thermal treatment on the mechanical properties and microstructure of polycarbonate

D. E. Chechin, L. A. Plyasunkova, P. A. Stepanov

This study describes the changes in microstructure and mechanical properties (tensile strength and tensile modulus) of polycarbonate following thermal treatment at 145 °C for 5, 10, 15, and 25 hours. The study was conducted using samples made from two grades of polycarbonate sheet – domestic VTP-8/PK-EA-7.0 and imported Lexan ULG 1003. It was observed that the material tensile strength increased after the internal stress relief, and subsequently decreased with an increase in thermal treatment time. Besides, it was noted that the material tensile modulus decreased after the internal stress relief, and subsequently stabilized, irrespective of thermal treatment time. Post-thermal treatment microstructural analysis revealed the formation of orthogonal cracks at fracture, which was indicative of the material embrittlement and reduced local plastic adaptability. Thermal effect induced the degradation of polycarbonate microstructure, accompanied by the formation of cracks, delaminations, and crystallization sites. The spherical domains of polycarbonate macromolecular chains were observed to increase in size, from 125 – 250 nm in the initial material to ~ 250 – 500 nm after thermal treatment for 15 – 25 hours.

Keywords: polycarbonate, crystallization, tensile strength, scanning electron microscopy.

DOI: 10.30791/1028-978X-2026-5-19-26

Reference citing:
Chechin D. E., Plyasunkova L.A., Stepanov P.A. Issledovanie vliyaniya termicheskogo vozdejstviya na mekhanicheskie svojstva i mikrostrukturu polikarbonata [Study of the effect of thermal treatment on the mechanical properties
and microstructure of polycarbonate]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 5, pp. 19 – 26. DOI: 10.30791/1028-978X-2026-5-19-26

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Effect of muscovite and magnesium spinel on the characteristics of polytetrafluoroethylene

Yu. V. Kapitonova, P. N. Tarasova, N. N. Lazareva, N. F. Timofeeva, A. A. Okhlopkova

The paper presents the results of studies of the effect of natural mica — muscovite and magnesium spinel on the structure and properties of polytetrafluoroethylene (PTFE) grade PN-90. Physical, mechanical and tribological tests of PTFE-based composite samples were carried out, and structure studies were conducted. It was found that with the addition of muscovite, the relative elongation index increases by 43%, wear resistance increases by 277 times compared to the original polymer, the friction coefficient is 0.24 – 0.29. With the additional addition of magnesium spinel, wear resistance increases to 312 times, and the friction coefficient decreases by 38 %. Structural studies were carried out using scanning electron microscopy with an attachment for elemental analysis and optical microscopy. The studies showed that the supramolecular structure is characterized by the formation of homogeneous structural elements that contribute to an increase in the deformation-strength indicators and wear resistance of the material. Studies of the friction surface showed that a decrease in the rate of mass wear of composites is also associated with the formation of a wear-resistant surface formed in the process of frictional interaction of the composite surface and the counterbody.

Keywords: polytetrafluoroethylene, muscovite, mica, magnesium spinel, polymer composite material, wear resistance, layered silicates, friction surface.

DOI: 10.30791/1028-978X-2026-5-27-33

Reference citing:
Kapitonova Yu.V., Tarasova P.N., Lazareva N.N., Timofeeva N.F., Okhlopkova A.A. Vliyanie muskovita i magnievoj shpineli na harakteristiki politetraftoretilena [Effect of muscovite and magnesium spinel on the characteristics of polytetrafluoroethylene]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 5, pp. 27 – 33. DOI: 10.30791/1028-978X-2026-5-27-33

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Kinetics of oxidation of zinc alloy ZnAlCuPd4-1-2,5 doped with strontium

N. A. Aminova, I. N. Ganiev, U. Sh. Yakubov, G. M. Rahmatulloeva

The paper considers the results of a study of the kinetics of oxidation of zinc alloy ZnAlCuPd4-1-2,5 with strontium in the temperature range 523 – 623 K and the resulting oxidation products of the alloys. The kinetics of oxidation of zinc ZnAlCuPd4-1-2,5 doped with strontium was studied by the thermogravimetric method in the solid state. Kinetic and energy parameters of the alloy oxidation process are determined. It was established that strontium additives within the studied concentration range increase the oxidation of the original ZnAlCuPd4 alloy in the temperature range of 523 – 623 K. The apparent activation energy of the oxidation process of the initial alloy ZnAlCuPd4-1-2,5 is 136.8 kJ/mol and decreases to 113.1 kJ/mol for the alloy with 1.0 wt.% Sr. The oxidation curves of the alloys of the ZnAlCuPd4 systems with strontium in the solid state are described by polynomials, indicating a hyperbolic mechanism of this process. The XRD method revealed that the oxidation products of alloys consist of oxides: Al2O3; Sr3Al2O6; Sr3PbO; SrZnO2; Al(OH)3 and CuAlO2.

Keywords: zinc alloy ZnAlCuPd4-1-2,5 strontium, thermogravimetric method, oxidation kinetics, true oxidation rate, activation energy.

DOI: 10.30791/1028-978X-2026-5-34-41

Reference citing:
Aminova N.A., Ganiev I.N., Yakubov U.Sh., Rahmatulloeva G.M. Kinetika okisleniya cinkovogo splava CAMSv4-1-2,5, legirovannogo stronciem [Kinetics of oxidation of zinc alloy ZnAlCuPd4-1-2,5 doped with strontium]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 5, pp. 34 – 41. DOI: 10.30791/1028-978X-2026-5-34-41

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

On the minimum oxygen content in aluminum nitride powders

N. S. Shibakova, S. A. Rogachev, V. V. Zakorzhevsky, N. V. Chapysheva, M. I. Alymov

In this article, we study the effect of the oxide layer thickness on the oxygen content in AlN powders widely used in modern industry. The materials under study were aluminum nitride powders synthesized in the ISMAN pilot plant by self-propagating high-temperature synthesis (SHS). The obtained powders were experimentally studied using X-ray diffractometry and scanning electron microscopy to determine particle size, phase composition, and morphology. The results allowed us to compare the calculated and experimental data on the oxygen content, demonstrating the effect of the oxide layer thickness and particle size on the total oxygen content in the AlN powder. The average oxygen content was calculated for aluminum powders with an average particle size of 1 – 7 μm, depending on the thickness of the oxide layer. The presented model and results can be used to optimize the processes of obtaining and processing AlN powders in order to minimize the impurity content and improve their performance characteristics.

Keywords: oxygen content, aluminum nitride powders, SHS, oxide layer, particle dispersion.

DOI: 10.30791/1028-978X-2026-5-42-49

Reference citing:
Shibakova N.S., Rogachev S.A., Zakorzhevsky V.V., Chapysheva N.V., Alymov M.I. O minimal'nom soderzhanii kisloroda v poroshkah nitrida alyuminiya [On the minimum oxygen content in aluminum nitride powders]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 5, pp. 42 – 49. DOI: 10.30791/1028-978X-2026-5-42-49

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Spark plasma sintering behavior of nano- and microcrystalline WC – 25 wt.% TiC powders

A. V. Terentyev, Yu. V. Blagoveshchenskiy, N. V. Isaeva, A. V. Nokhrin,
E. A. Lantsev, A. A. Murashov, K. E. Smetanina

The sintering mechanisms of nanopowder WC–25 mass.% TiC compositions with titanium carbide of varying dispersity were investigated. WC–TiC ceramics were fabricated via spark plasma sintering (SPS) in vacuum within the temperature range of 1000 – 1400 °C at a heating rate of 50 °C/min under an applied pressure of 70 MPa and various dwell times. Plasma‑chemical tungsten monocarbide nanopowders and nano- and submicron‑sized titanium carbide powders were used as starting materials. The microstructure, phase composition, and density of the sintered ceramics were examined. It was demonstrated that SPS enables the production of WC–TiC ceramics with a homogeneous ultrafine-grained structure (0.2 – 0.5 μm). X-ray phase analysis revealed the formation and evolution of the (Ti,W)C solid solution during sintering. The sintering kinetics exhibit a multistage behavior characteristic of the SPS process in WC–TiC systems. It was established that the use of nanoscale titanium carbide particles leads to earlier dominance of mass transfer along grain boundaries and interphase contacts due to an increased fraction of active contact areas. In contrast, submicron TiC particles result in a more pronounced maximum shrinkage rate associated with the rapid involvement of larger material volumes in the diffusion flux. The presence of vacancies in the carbon sublattice of titanium carbide plays a key role in activating diffusive mass transfer and forming the (Ti,W)C solid solution.

Keywords: titanium carbide, tungsten carbide, spark plasma sintering, phase composition, diffusion.

DOI: 10.30791/1028-978X-2026-5-50-61

Reference citing:
Terentyev A.V., Blagoveshchenskiy Yu.V., Isaeva N.V., Nokhrin A.V., Lantsev E.A., Murashov A.A., Smetanina K.E. Issledovanie osobennostej elektroimpul'snogo plazmennogo spekaniya nano- i mikroporoshkov WC – 25 %TiC [Spark plasma sintering behavior of nano- and microcrystalline WC – 25 wt.% TiC powders]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 5, pp. 50 – 61. DOI: 10.30791/1028-978X-2026-5-50-61

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Electron-beam synthesis of complex titanates

S. A. Ghyngazov, I. P. Vasil’ev, V. A. Boltueva

Ceramic synthesis is the most important stage of ceramic production. Reducing its energy consumption and time costs is the goal of many studies. As an alternative to traditional solid-phase synthesis, synthesis in a powerful beam of fast electrons is considered. Mixtures of Al2O3 + TiO2 oxides with and without the addition of ZrO2 were heated in air by electrons with an energy of 1.4 – 2.5 MeV at a power density of up to 25 kW/cm2 and higher at a movement speed of the cuvette with the powder mixture of oxides in the irradiation plane from 0.25 to 1 cm/s. The mixture melted during irradiation and the synthesis of complex titanates in the form of ceramic drops with a porous structure took place. It was found that porosity is regulated by irradiation parameters and cuvette movement speed. The synthesized ceramics have an oxygen deficiency and a characteristic gray-blue color. Annealing in air is accompanied by oxidation of the ceramics and transformation of this color into white. This occurs due to a change in the valence of a small part of Ti included in the ceramics from Ti3+ to Ti4+ as a result of oxidation. The thermal expansion curve shows hysteresis, indicating phase transformations due to oxidation. After thermal annealing in the atmosphere, the hysteresis disappears. Electron beam processing of the Al2O3 + TiO2 mixture with the addition of ZrO2 led to the synthesis of glass ceramics of a complex composition containing zirconolite. Zirconolite is currently the most promising material for the immobilization of radioactive materials. The main reason for the complication of the glass ceramics composition was the presence of uncontrolled impurities in the original mixture, in particular Ca. The hardness of the ceramics, depending on the porosity and synthesis conditions, can vary from 1.5 to 10.5 GPa.

Keywords: titanates, zirconolite, synthesis, electron beam.

DOI: 10.30791/1028-978X-2026-5-62-74

Reference citing:
Ghyngazov S.A., Vasil’ev I.P., Boltueva V.A. Elektronno-luchevoj sintez slozhnyh titanatov [Electron-beam synthesis of complex titanates]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 5, pp. 62 – 74. DOI: 10.30791/1028-978X-2026-5-62-74

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Study of morphology and tribomechanical properties of nanostructured ceramic coatings obtained by magnetron sputtering on Y-TZP ceramic base

R. S. Nebogatikov, A. A. Serdobintsev, A. M. Zakharevich, S. Ya. Pichkhidze

The application of nanostructured ceramic coatings (Cr2O3 and SiO2-Cr2O3) was conducted on a Y-TZP ceramic base, utilising the process of direct current magnetron sputtering. Prior to the coating process, the Y-TZP samples underwent a rigorous 4-stage polishing procedure involving the utilisation of micron and submicron diamond polycrystalline suspensions. This was followed by the creation of an SiO2 adhesion layer through the process of dipping the samples in a 2.5 ± 0.5 % volumetric alcohol solution of C9H23NO3Si. Subsequently, the samples 5 – 7 underwent a diffusion oxidation process at a temperature of 450 °C for a duration of 30 minutes. In the final stage of the process, Cr with a chemical purity of 99.99 % was sprayed, followed by a diffusion oxidation process in air at a temperature of 450 °C for a duration of 30 minutes. A series of experimental studies have demonstrated that the surface of the deposited material exhibited particle sizes ranging from 50 ± 11 nm to 74 ± 34 nm, pore areas ranging from 33 ± 10 nm2 to 818 ± 30 nm2, and open porosity ranging from 3.3 ± 0.1 % to 13.4 ± 0.2 %. It was determined that the highest wear resistance values (~4×107) are achieved when forming SiO2-Cr2O3 coatings with a thickness of 140 – 360 nm, a particle size of 60 ± 10 nm, a pore area of 0.040 ± 0.005 μm2, an open porosity of up to 3.5%, a roughness of Ra up to 20 nm, and a microhardness of 2000 ± 200 HV.

Keywords: nanostructured ceramic coatings, ceramic materials based on tetragonal zirconium dioxide, tribomechanical properties, prosthetic heart valve.

DOI: 10.30791/1028-978X-2026-5-75-88

Reference citing:
Nebogatikov R.S., Serdobintsev A.A., Zakharevich A.M., Pichkhidze S.Ya. Issledovanie morfologii i tribomekhanicheskih svojstv nanostrukturirovannyh keramicheskih pokrytij, poluchennyh metodom magnetronnogo raspyleniya na keramicheskoj osnove Y-TZP [Study of morphology and tribomechanical properties of nanostructured ceramic coatings obtained by magnetron sputtering on Y-TZP ceramic base]. Perspektivnye Materialy [Advanced Materials] (in Russ), 2026, no. 5, pp. 75 – 88. DOI: 10.30791/1028-978X-2026-5-75-88