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.

This study concerns droplet phase influence and process parameters influence (laser radiation power, oblique deposition, residual oxygen pressure, etc.) on morphology and composition of the coating and formation of oxides in the coating during pulsed laser deposition of Titanium on inner surface of tubes. It is shown that droplets in the coating in the presence of residual oxygen significantly affect the composition of Ti-coatings.

The conductivity of surface layer of polycrystalline CVD (Chemical Vapor Deposition) diamond has been studied experimentally after high-fluence 30keV Ne+, 20 and 30keV Ar+ ion irradiation at target temperature range from 30 to 400°C. The hot ion irradiation of CVD diamond may be described as ion-stimulated heat graphitization in which an exponential resistance decrease with increasing of the irradiation temperature is much faster than at the heat treatment. Under ion irradiation of CVD diamond the graphite-like materials resistivity is achieved at temperatures not exceeding 200°C. The graphite phase in a heterogeneous structure of diamond irradiated layer is in dynamic equilibrium. In the temperature range from RT to 400°C, the proportion of graphite phase increases so that at temperatures 200<Tir<400°C it is dominant. The Raman spectra of ion-induced conductive layer created on CVD diamond reflect the processes of nanostructural ordering – disordering of sp2-bonded carbon.

Diamond-like coatings with a total thickness of ~0.6 μm are obtained by physical vapor deposition with plasma separation and a pulsed carbon arc source with a cooled cathode and laser arc ignition; the substrates are titanium alloy (VT4), stainless steel (12Cr18N10T), and copper (M1). Scanning electron microscopy and profilometry are used to study the coatings surface and structure. The composition of the coatings and the fraction of sp3 bonds are studied using Raman spectroscopy. A wide peak in the 1580 cm-1 region is observed characteristic of diamond-like coatings. The coatings have a dense, nonporous structure. The tribological properties of the coatings are evaluated by the ball-on-disk method using a friction pair with WC and technical diamond. The strength characteristics are determined using linear scratch testing and nanoindentation measurements. The strength characteristics of the coatings vary and depend on the substrate materials. The friction coefficient of a diamond-like coating on VT4 alloy is ~0.1 in a friction pair with WC and ~0.01 with technical diamond.

Work is devoted to detection of distinctive characteristics of allotropic forms of carbon which would provide their identification from mixes. The complex analysis is offered by methods: the synchronous thermal analysis with studying of composition of the emitted gases and Raman spectroscopy. It was shown that researches of carbon structures and their mixes by the declared methods agree well and complement each other.

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.

The modification of (111) face of synthetic diamond has been studied experimentally for high-fluence 30 keV argon bombardment. It has been found that ion irradiation leads to the electrically conductive layer formation the sheet resistance of which decreases more than 100 times while changing the temperature of the irradiated diamond from 70 to 400 oC. This effect, as well as significant changes of optical transmittance after ion irradiation are associated with ion-induced structural changes of irradiated diamond obtained by the methods of Raman spectroscopy.

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.

The results of an experimental study of the structural and morphological changes in the surface layer of SU-2500 glassy carbon due to high-dose 30 keV Ar+ ion irradiation in the temperature range of 60–400°C are presented and discussed. The given study is performed via the Raman scattering (RS) of laser radiation with the wavelengths 514 and 244 nm. Data analysis makes it possible to identify the nanocrystalline state of the surface layer at irradiation temperatures of 140–250°C and its amorphisized and polycrystalline states at room and elevated temperatures, respectively. The D peak of RS spectra is not observed at λL = 244 nm. It is demonstrated that ion bombardment leads to appreciable suppression of the G peak and can be used to reveal ion-induced states in carbon materials.

The results of experimental investigation into modification of the (111) face of a synthetic diamond crystal under high-fluence 30-keV Ar+ irradiation are presented. It is found that irradiation at a temperature of 400°C leads to the formation of a conductive surface layer, which is detected in the Raman spectra as a broad band with a maximum close to the position characteristic of the G peak of graphite at 1580 cm−1. In addition, the intensity of the narrow peak of diamond at 1332 cm−1 decreases by an order of magnitude. Ion irradiation is accompanied by the suppression of the initial photoluminescence and gives rise to weak photoluminescence with a spectrum characteristic of gem diamonds.

Приводятся и обсуждаются результаты экспериментального исследования структурных и морфологических изменений поверхности стеклоуглерода марки СУ-2500 высокодозным облучением ионами Ar+ с энергией 30 кэВ в диапазоне температур 60–400°С с использованием комбинационного рассеяния лазерного излучения с длинами волн 514 и 244 нм. Анализ данных позволил идентифицировать нанокристаллическое состояние поверхностного слоя при температурах облучения 140–250°С, аморфизованное состояние при температурах, близких к комнатной, и поликристаллическое при повышенных температурах. При Л = 244 нм D-пик в спектрах комбинационного рассеяния не наблюдается. Ионное облучение приводит к значительному подавлению G-пика, что может быть использовано для выявления ионно-индуцированных состояний в углеродных материалах.

Приводятся результаты экспериментального исследования модификации грани (111) синтетического алмаза при высокодозовом облучении ионами Ar+ с энергией 30 кэВ. Найдено, что облучение при температуре 400°C приводит к появлению проводящего поверхностного слоя, проявляющегося в спектрах комбинационного рассеяния света в виде широкой полосы с максимумом, близким к положению характерному для G-пика графита при 1580 см-1. При этом интенсивность узкого пика алмаза при 1332 см-1 уменьшается на порядок. Ионное облучение сопровождается подавлением исходной фотолюминесценции и вызывает появление слабой фотолюминесценции со спектром, характерным для ювелирных алмазов.