В работе рассмотрены достижения последних лет в области проектирования и изготовления искусственных самовосстанавливающихся материалов и композиционных систем, которые могут быть использованы в качестве защиты от повреждающих факторов внешней среды. Рассмотрены принципы самозалечивания в искусственных материалах и прототипы таких материалов, имеющих потенциал применения в космической технике. Особое внимание уделено полимерным материалам с динамически подвижными молекулярными связями и композитным материалам с внутренними наполнителями, осуществляющими процессы самозалечивания. Отмечено, что слоистая структура композитного материала с внутренним вязкотекучим наполнителем, за счёт направленного массопереноса вязкотекучего компонента и его консолидации в области дефекта, способна быстро восстанавливать герметичность материала после сквозных повреждений. Продемонстрированы лабораторные прототипы самозалечивающихся материалов, среди которых выделяются слоистые композитные материалы, способные самостоятельно восстанавливать герметичность менее чем за секунду, что открывает перспективы их использования в надувных конструкциях для защиты от утечек внутренней атмосферы. The paper considers the achievements of recent years in the design and manufacture of artificial self-healing materials and composite systems that can be used as protection against damaging environmental factors. The principles of self-healing in artificial materials and prototypes of such materials that have the potential to be used in space technology are considered. Particular attention is paid to polymeric materials with dynamically mobile molecular bonds and composite materials with internal fillers that carry out self-healing processes. It is noted that the layered structure of a composite material with an internal viscous filler, due to the directed mass transfer of the viscous component and its consolidation in the defect area, is able to quickly restore the tightness of the material after through damage. Laboratory prototypes of self-healing materials have been demonstrated, among which layered composite materials stand out that can independently restore tightness in less than a second, which opens up prospects for their use in inflatable structures to protect against leakage of the internal atmosphere.

В статье приведены результаты исследования комплексом физических методов нанотолщинного газонепроницаемого эрозионностойкого покрытия из оксида алюминия, полученного методом атомно-слоевого осаждения, до и после его контакта с высокотемпературной восстановительной газовой средой в течение 1500 с. Установлено, что после этого указанные покрытия не изменились. Сделан вывод о перспективности использования этих покрытий для антиэррозионной защиты поверхностей, контактирующих с высокотемпературными газовыми потоками The article presents the results of investigation performed by the complex of physical methods of nanolayer gastight erosion-resistant aluminum oxide coating produced by atomic layer deposition before and after its contact with high-temperature reducing gas medium during 1500 seconds. It has been established that after that the mentioned coatings have not changed. It is concluded that these coatings are potential for anti-erosion protection of surfaces in contact with the high-temperature gas flows

Методами растровой электронной, атомно-силовой микроскопии, спектроскопии комбинационного рассеяния света и рентгеновской дифрактометрии изучено газонепроницаемое эрозионно-стойкое покрытие из оксида алюминия до и после контакта с высокотемпературной восстановительной газовой средой. Установлено, что указанные покрытия толщиной от 180 нм до 300 нм, полученные методом атомно-слоевого осаждения, не изменились после контакта в течение 4500 с при температуре (950±50) К с восстановительной газовой средой. Данное обстоятельство позволяет использовать их для защиты поверхностей, корродирующих при контакте с высокотемпературными газовыми потоками. Scanning electron microscopy, atomic force scanning microscopy, Raman spectroscopy, and X-ray diffractometry were used to study a gas-tight erosion-resistant aluminum oxide coating before and after contact with a high-temperature reducing gas medium. It has been found that these coatings with a thickness of 180 nm to 300 nm, obtained by atomic layer deposition, did not change after contact for 4500 s at a temperature of (950±50) K with a reducing gas medium. This circumstance makes it possible to use them to protect surfaces that corrode upon contact with high-temperature gas flows.

The prospects of using combined-type installations equipped with laser and electron-beam sources in the field of additive technologies are shown. The problem of broadening of the electron beam acting on the surface of the workpiece in a vacuum medium due to its scattering by particles of the evaporating material is considered. An analytical solution is obtained of the paraxial equation of the envelope of an electron beam undergoing scattering in the atmosphere of evaporated particles. The conditions are established that ensure stable transportation of the electron beam to the surface to be treated.

This article describes development of an aluminum composite with a matrix of mixed powdered aluminum, nickel, copper, and boron hardened by 0.01–0.1 wt % alumina nanofibers (Nafen™). The composite samples have been produced by conventional powder metallurgy including pressing and sintering in vacuum furnace. The microstructure and fine structure of aluminum composites, average grain diameter, density, phase composition, Vickers microhardness, and ultimate bending strength at ambient temperature and at 300°C have been analyzed. According to X-ray diffractometry, the samples contain the phases of Al, Al 3 Ni, CuAl 2 , Al 7 Cu 23 Ni, and Ni 4 B 3 . The microhardness increases monotonically with concentration of alumina nanofibers. It has been established that, at ambient temperature, the strength of the samples with 0.01–0.1 wt % of alumina nanofibers is higher by 30% on average than that of the matrix. During tests at 300°C, the best result has been shown by the sample with 0.01 wt % of nanoparticles; its strength was by 14% higher than that of the matrix.

Self-healing materials are of increasing interest for science and industry. However, such materials and technologies based on them are not widely implemented at the large-scale industrial level. There are reports on single successful implementations of such technologies; the concept of artificial self-healing of nonbiological materials is mostly actualized in prototypes for self-healing materials and systems. Self-restoring of the initial characteristics of materials is the most successfully realized in polymers and compositions based on them, and polymer coatings are the most applicable and commercially demanded self-healing materials. In this article, the basic mechanisms of self-healing of the initial characteristics in materials of different types are briefly presented and the technologies based on them are considered. The data on self-healing materials of different chemical nature (polymers, cements, ceramics, metals, and composite materials) are analyzed. The physical and chemical principles of providing the effect of self-restoring of the initial characteristics are highlighted, and the prospects of practical implementation of self-healing materials and technologies on their basis are discussed. The sources of information used were overviews on self-healing materials of different types, patents, and scientific articles.

The characteristic features, properties and phase composition of the surface of nano and microcrystals of diamond of detonation synthesis subjected to graphitization are studied. The patterns of this process and the accumulation of graphitization products have been studied by applying Raman scattering, electron microscopy on an electron microscope, and X-ray phase analysis of micropowder samples. As objects of research, samples of chemically purified detonation nano and microdiamonds obtained by detonation synthesis were used. The used samples of carbon particles were investigated in the temperature range of 20 - 1500 °C, in an inert gas atmosphere, at different heating rates of the object. The graphitization of nanodiamonds is characterized by rigorous stage transformations associated with the growth of Raman intensities of Raman peaks (1350 and 1610 cm-1) characterizing graphitization associated with the appearance and accumulation of sp2-type carbon bonds. The recorded manifestations of Raman scattering are associated with the appearance and accumulation of crystalline and amorphous products of nanodiamond graphitization. The final products of the process studied had a Raman peak at 1575 cm-1, which directly indicates the appearance of onion-like forms of carbon on the surface of the nanodiamond particles studied. The distinctive features of the dynamics of graphitization of the surface of carbon particles having different structural organization are established. Nanodiamond particles are more sensitive to graphitization processes than microdiamond particles, and their changes are deeper. The graphitization of nano and microdiamond particles is accompanied by the transition of the surface carbon from sp3 to the sp2 phase, as well as the appearance of various forms of the amorphous phase. This process is characterized by the appearance and accumulation of onion-like graphite products (onions). The peculiarities of graphitization of microdiamonds are associated with the appearance of onion-like extended structures, which are much larger in size than microstructures, in comparison with onions arising from detonation nanodiamonds.

Fabrication a composite materials based on silicon carbide (SiC) reinforced with multi-walled carbon nanotubes (MWCNTs) with addition of magnesium alumina spinel MgAl2O4, and yttrium aluminum garnet Y3Al5O12 by spark plasma sintering are presented. Two series of composites differing by the particle size of starting SiC were prepared. Mechanical characteristics of composites including microhardness, fracture toughness and flexural strength are determined.

Aluminum composites doped with copper (4 wt %) with micro-additions (0.01–0.15 vol %) of oxide nanoparticles (Al2O3, ZrO2, MgO, SiO2) are synthesized by the powder metallurgy method. Their microstructure and mechanical properties (Brinell hardness number, Vickers microhardness) are investigated. Existence of phases CuAl2 both on the boundaries and inside grains of the matrix are revealed. Optimal concentrations of nanoparticles that provide high mechanical properties are determined. For Al–Cu material with 0.15 vol % of aluminum oxide, a maximum increase in Brinell hardness of 17% (68 HB) with respect to aluminum composite without nano-additions sintered according to the same technology is observed. Among the investigated materials, the highest Vickers microhardness of 0.543 GPA is intrinsic to aluminum composite with Al2O3 content of 0.1 vol %.

We have studied the properties of transparent magnesium aluminate spinel ceramics prepared by spark plasma sintering (SPS) of ultrapure nanopowders. The starting powders, of ≃ 99.98% purity, ranging in specific surface area from 30 to 160 m2/g, were prepared through the hydrolysis of alcoholic solutions of magnesium aluminum alkoxide complexes, followed by calcination at temperatures from 900 to 1100°C. SPS was carried out at 1450°C, with the holding time at the highest temperature not longer than 15 min. The transparent ceramic samples thus prepared have a transmission of up to 73% in the visible and IR spectral regions (λ = 2.5–5.0 µm). The crystallite size in the ceramics is 0.2–0.4 µm, and their microhardness is HV0.1 = 14.8–16.2 GPa.

Original data on the formation of fractal structures via the pulsed laser deposition of titanium in a high vacuum without external electric or magnetic fields are presented. The obtained thread-like structures are thin-walled strained tubes with diameters of 1–3 μm and lengths of up to 500 μm. The composition and structure of the samples are investigated.

This paper presents the results of research of laser ablation, carried out at 85° incidence angle of the laser ray to the normal to surface of target with simultaneous spatial restriction of plasma torch. It is shown that laser radiation reflected from the target falls on the substrate and produces ablation. Consequently ablated material of the substrate is transferred to the target. It is found, that direct and reflected from the target laser radiation form periodic wave-shaped structures on the surface of target and substrate.

The characteristics, properties and phase composition of surface of nano-and microdiamond crystals obtained by detonation synthesis were researched. In blend composition of nano diamonds the carbine presence was revealed. On the surface of the nano diamond microcrystals and after chemical treatment the presence of sp(2) and sp(3) carbon phases with the predominant content of sp(3) crystal phase was revealed. Together with that the presence on the surface of the sp(3) amorpohous phase was established for nano diamonds.

Results from structural and morphological studies, measurements of the sheet electrical resistance, and estimating resistivity ρm of a graphite-like conducting surface layer formed upon high-dose irradiation of the (111) face of a synthetic diamond with Ar+ ions at an energy of 30 keV and a target temperature of 400°C are presented. It is found that the orienting effect of the diamond lattice is visible in the suppression of the formation of graphite crystallites with axis c perpendicular to the surface. The thickness of the modified layer is 40–50 nm, and its sheet resistance is 0.5 kΩ/sq. Resistivity ρm = 20–25 μΩ m of the modified layer lies within the range of ρ values of graphite and glassy carbon materials.