Tilda Publishing

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Tilda Publishing

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

2024, No. 6, CONTENTS

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Tilda Publishing

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

2024, No. 6, ABSTRACTS

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Influence of activation of reinforcing UHMWPE-fibers on the properties of composite materials

N. V. Korneeva¹, I. Sh. Abdullin<sup>2

1</sup> Semenov Federal Research Center of Chemical Physics, Russian Academy of Sciences,
4 Kosygin str., 119334 Moscow, Russia
E-mail: natakorneeva@mail.ru
² Research and production association “Plasma VST”,
27 Kurskaya str., 420081 Kazan, Republic of Tatarstan, Russia
E-mail: plasma.vst@gmail.com

The article presents the results obtained in the study of the influence of UHMWPE-fibers activation by non-equilibrium low-temperature plasma of a high-frequency capacitive discharge at reduced pressure and direct fluorination on the properties and failure mode of polyethylene plastic composite materials. The application of activated UHMWPE-fiber for reinforcing an epoxy and epoxy-urethane matrices make it possible to produce light-weight composite materials with high physicomechanical indices. The interaction between the fiber and the matrix during the production of CM can be increased both by activating the fiber and by choosing the composition of the matrix. The plasma treatment and direct fluorination appeared to be particularly effective for study the effect of fiber activation on the bending and shear properties of the composite thus demonstrating high increase of the interaction at the fiber/matrix interface. After the plasma treatment of SK-75, the composite bending strength, sb, based on Epicot-828 and on EPUR matrices was increased by a factor of 3 from 155 to 470 MPa and 2.96 (~ 3) from 145 to 430 MPa respectively. The shear strength, tsh, increased by the factors of 1.66 from 12 to 20 MPa and 1.57 (~ 3) from 18 to 30 MPa for the composites reinforced with plasma-activated SK-75 fibers based on Epicot-828 and on EPUR matrices respectively. The composite shear, tsh, and bending strength, sb, increased by the factors of 2.2 from 10 to 22 MPa and 2 from 160 to 320 MPa for CM based on Epicot-828 reinforced with activated SK-75 fibers by direct fluorination. Activation of the fiber with the help of plasma and fluorination allows оne to make polyethylene plastic a monolithic composite. The failure mode of such composites points to the high strength of the bond between the fiber and the matrix.

Keywords: ultra-high molecular weight polyethylene fiber (UHMWPE-fiber), activation, treatment of UHMWPE-fibers, non-equilibrium low-temperature plasma, high frequency capacitive discharge under low pressure, fluorination, composite material, polyethylene plastic, active centers, crazes, failure mode of the composites.

DOI: 10.30791/0015-3214-2024-6-5-21

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Features of diffusion welding of Inconel 718 samples
obtained by selective laser melting

A. V. Liushinskii¹, A. V. Semenov², A. N. Servetnik<sup>2

1</sup> LLC “Aviation and Space Technologies”, office 332, bl. 1, 42 Bulvar Bolshoi, 121205 Moscow, Skolkovo, Russia
Е-mail: nilsvarka@yandex.ru
² Central Institute of Aviation Motors, 2 Aviamotornaja str., 111116 Moscow, Russia
E-mail: avsemenov@ciam.ru

The features of diffusion welding of samples from Inconel 718 alloy obtained by additive manufacturing using the selective laser melting (SLM) method were investigated. Optimal welding mode parameters were selected to ensure maximum strength properties of the material: T = 1000 °C, P = 32 MPa, t = 30 min.

Keywords: diffusion welding, additive technology, ovenproof alloy, temperature, welding force, durable.

DOI: 10.30791/0015-3214-2024-6-22-26

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Preparation of alloys and intermetallic compounds of the Ti – Cu system
from mixtures of Ti and Cu powders

G. A. Pribytkov, A. V. Baranovskiy, V. V. Korzhova, I. A. Firsina, V. P. Krivopalov

Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Science (ISPMS SB RAS),
2/4 Academicheskii av., 634055 Tomsk, Russia
E-mail: gapribyt@mail.ru; nigalisha@gmail.com;vicvic5@mail.ru; iris1983@yandex.ru; krivopalov@ispms.tsc.ru

The phase composition of materials obtained by heat treatment of titanium – copper powder mixtures with an elemental composition corresponding to binary intermetallic compounds TiCu and Ti2Cu has been studied. Heat treatment included short-term heating of mechanically activated mixtures to 800 °C or sintering of compacts from the mixtures. It has been established that, regardless of the heat treatment modes, the reaction products when heating mixtures are multiphase, but the main phase in all cases is the Ti3Cu4 intermetallic compound, which, according to reference data, has the highest negative enthalpy compared to other binary intermetallic compounds. This fact of the determinant influence of the thermodynamic factor on the phase composition of reaction products in mixtures of metal powders in systems with intermetallic compounds is consistent with previously published results on the titanium – nickel, titanium – iron and titanium – aluminum systems, as well as on the ternary titanium –aluminum – silicon system. The possibility of using multiphase synthesis products in mixtures of titanium and copper powders to obtain metal-matrix composites “titanium carbide – copper binder” through the reaction with carbon is substantiated.

Keywords: powder mixtures, mechanical activation of synthesis, titanium – copper intermetallic compounds, phase composition, enthalpy of formation of compounds.

DOI: 10.30791/0015-3214-2024-6-27-37

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Effect of the type of dispersoids on the tribological properties
of sintered Al – 20 vol. % Sn alloy

N. M. Rusin, А. L. Skorentsev

Institute of Strength Physics and Materials Science of the Siberian Branch of the Russian Academy of Sciences (ISPMS SB RAS),
2/4 pr. Akademicheskii, 634055 Tomsk, Russia
E-mail: rusinnm@mail.ru; skoralexan@mail.ru

The structure and the mechanical and tribological properties determined by it of sintered Al – 20 vol. % Sn (Al – 40 wt. % Sn) composites hardened by dispersed hard particles of various types were studied in the work. While maintaining the volume fraction of tin, particles of B4C, SiC, Al3Ti and Al3Fe with a volume fraction of about 20 % were added into the alloy as a strengthening phase. The mixtures were sintered at temperatures below (620 °C) and above (710 °C) the melting point of aluminum. In order to eliminate residual pores, the sintered samples were subjected to subsequent compaction in a closed die at a temperature of 250 °C and a pressure of about 300 MPa. Tribological tests of sintered composites were carried out under dry friction according to the “pin-on-disc” scheme against a steel counterbody. It was found that many of the initial boundaries of iron and titanium aluminides with aluminum grains were preserved during the sintering process, while the carbide particles were completely separated from the aluminum matrix by thin tin interlayers. It was established that the strength of composites with aluminides was higher, and the ductility was lower than that of composites with ceramic particles, regardless of the sintering temperature. It was found that an increase in the sintering temperature has virtually no effect on the wear resistance of hybrid composites during dry friction, with the exception of a composite reinforced with iron aluminides, the wear resistance of which increases by approximately 20 %. With increasing pressure, the wear rate of sintered composites during dry friction against steel increases, so it is not recommended to use these materials as antifriction ones at pressures above 3 MPa.

Keywords: antifriction aluminum alloys, dispersion hardening, sintering, mechanical properties, wear resistance.

DOI: 10.30791/0015-3214-2024-6-38-51

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Effect of creep on the microstructure of aluminum alloy AD1
in recrystallized and ultrafine-grained states

S. S. Manokhin¹, D. A. Kolesnikov², I. V. Nelasov¹, Y. R. Kolobov¹, D. V. Lazarev²,
V. I. Betekhtin³, A. G. Kadomtsev³, M. V. Narykova<sup>3

1</sup> Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry RAS (FRC PCP MC RAS),
1 Ac. Semenov avenue, 142432 Chernogolovka, Russia
² Belgorod State National Research University (BSU),
85 Pobedy str., 308015 Belgorod, Russia

3 The Ioffe Physical-Technical Institute of the Russian Academy of Sciences (Ioffe Institute RAS),
26 Politekhnicheskaya str., 194021 Saint Petersburg, Russia
Changes in the microstructure of industrial aluminum alloy AD1 in recrystallized and ultrafine-grained (UFG) states before and after tensile creep tests at 0.3Tpl (100 °C) have been investigated. It was found that in the process of creep in the recrystallized structure there is a crushing of large elongated grains into grains and subgrains of smaller size, while the proportion of low-angle boundaries increases. In the UFG structure, grain growth (collecting recrystallization) is observed during creep. The presence of strong radial texture is established: [001] crystallographic direction of grain lattices is predominantly parallel to the axis along the axis of the original round bar, from which samples for research were cut parallel to the rolling direction. This texture is characteristic of specimens in both of the above-mentioned states. After creep tests, a change in the texture axis from [001] to [011] is observed in specimens with UFG structure. In addition, the formation of particles of secondary phases — aluminum carbide and silicon compounds, which were identified using the calculation of phase diagrams in the framework of CALPHAD methodology. The dislocation structure was investigated.

Keywords: aluminum alloy, recrystallization, ultrafine-grained, structure, phase, low-temperature creep, scanning electron microscopy, transmission electron microscopy, texture, microstructure, average grain size.

DOI: 10.30791/0015-3214-2024-6-52-66

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Investigation of luminescence and Raman spectra of doped hydroxylapatite
Ca5OH(PO4)3:Eu3+ and Ca5OH(PO4)3:Eu3+, Dy3+

A. F. Banishev

National Research Centre “Kurchatov Institute”, 1 Academician Kurchatov square, 123182 Moscow, Russia
E-mail: banishev@mail.ru

Hydroxylapatite is one of the main inorganic biocompatible materials used in orthopedics and dentistry as a therapeutic drug. Hydroxylapatite doped with ions of rare earth elements is widely used in biomedicine to visualize the processes occurring in biological objects, acting as a biological probe. At the same time, it is necessary that the doped hydroxyapatite be non-toxic, have a high yield of photoluminescence (fluorescence), which is not absorbed in the tissues of the biological object. In this regard, there is a need to study different methods of synthesis and doping of hydroxyapatite. In this work, the doping of hydroxylapatite (HAP) with Eu3+ ions, and together with Eu3+ and Dy3+ ions, was investigated. Doping was carried out by high-temperature annealing (T = 20 – 1350 °C) of a mixture of hydroxylapatite powder Ca5OH(PO4)3 with powders of europium oxides Eu2O3 and dysprosium Dy2O3. To determine the optimal annealing temperature at which the maximum fluorescence intensity is achieved, annealing was carried out in stages, at different temperatures of 800 °C, 945 °C, 1200 °C and 1350 °C in a vacuum furnace, the residual gas pressure in the chamber P = 1,3 Pa. The change in the structure of hydroxylapatite as the annealing temperature increases and the formation of luminescence centers in hydroxylapatite as a result of thermal diffusion of Eu3+ and Dy3+ ions from the corresponding europium oxides Eu2O3 and dysprosium Dy2O3 into the structure of hydroxyapatite was recorded using photoluminescence and Raman spectra. A 405 nm diode laser was used to excite the photoluminescence spectra. The excitation of the Raman spectra was carried out by a laser at a wavelength of 785 nm. Hydroxylapatite doped with Eu3+ DOI: 10.30791/0015-3214-2024-6-67-77and Dy3+ ions with pronounced photoluminescence at a wavelength of 573 nm was obtained by high-temperature annealing.

Keywords: hydroxylapatite, biocompatible, rare earth elements, high temperature annealing, thermal diffusion, doping, visualization, Raman spectra, luminescence spectra.

DOI: 10.30791/0015-3214-2024-6-67-77

ПЕРСПЕКТИВНЫЕ МАТЕРИАЛЫ

Reuse of dimethyl sulfoxide in the hydrolysis
of polyethylene terephthalate for recycling plastic waste
into porous carbon material

A. A. Vasilev, M. N. Efimov, D. G. Muratov, A. A. Panin, G. P. Karpacheva

Topchiev Institute of Petrochemical Synthesis of the Russian Academy of Sciences,
29 Leninsky prospect, 119991 Moscow, Russia
E-mail: raver.vasiljev@mail.ru

The method for chemically recycling polyethylene terephthalate into porous carbon material was considered. The method involves alkaline hydrolysis of plastic bottles, previously dissolved in dimethyl sulfoxide. This process results in the formation of potassium terephthalate, followed by pyrolysis at 850 °C. For the first time, the reuse of dimethyl sulfoxide for the dissolution of subsequent batches of polyethylene terephthalate waste was studied. The proposed method involves evaporating water from a mixture of dimethyl sulfoxide and the alkaline hydrolysis products of polyethylene terephthalate. It was shown that despite the change in the coloration of the solvent, its reuse did not affect the alkaline hydrolysis process of plastic bottles, resulting in the formation of potassium terephthalate. Subsequent pyrolysis of this compound led to the creation of porous carbon material with similar morphological and structural characteristics. It was found that all the carbon materials prepared were characterized by a defective graphite-like structure, with a specific surface area ranging from 1407 to 1595 m²/g and the presence of surface oxygen-containing groups.

Keywords: polyethylene terephthalate, hydrolysis, potassium terephthalate, activated carbon, IR pyrolysis.

DOI: 10.30791/0015-3214-2024-6-78-87