Articles

 


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1.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-3-9
УДК 621.762
Iatsyuk I.V., Artemenko N.I., Doronin O.N., Nerush S.V.
APPLICATION OF GAS ATOMIZATION TECHNOLOGY TO OBTAIN HIGH-QUALITY METAL POWDER COMPOSITIONS FOR APPLYING ATMOSPHERIC PLASMA COATINGS

At present, one of the most pressing scientific and technical problems is to improve the characteristics of products operating in extreme operating conditions. It is often sufficient to modify the surface by applying multifunctional coatings. The technology of atmospheric plasma spraying of coatings for the protection of large-sized parts, including combustion chambers, as well as parts of the hot tract of industrial and power gas turbine plants, has wide industrial applications. The advantages of this technology are small thermal deformations and the absence of structural changes on the surface. This technology allows you to apply antifriction, wear-resistant, heat-resistant, electrical insulating, electrically conductive coatings.

Obtained at FSUE «VIAM» using the gas atomization technology MPC from alloys of the NiCrAlY system for atmospheric plasma spraying are unique materials of a new generation containing elements such as rhenium and hafnium. Studies have shown that the particle size distribution of the IPC includes about 13% of the fraction with a particle size of up to 20 microns, about 60% of the fraction with a particle size of 20–45 microns. The remaining 27% of the particles are represented by large fractions larger than 45 microns. In this case, the powder particles have a spherical shape and are characterized by a small number of satellites and other defects.

The obtained results of the chemical analysis of the IPC indicate a high accuracy in reproducing the composition of the initial preform: quantitative deviations of the chemical composition of the MPC from the chemical composition of the preform for spraying are insignificant and do not exceed 1–5%, but the qualitative composition coincides. Analysis of gas impurities in the powder showed the presence of oxygen in an amount of 0,023%, and nitrogen in an amount of 0,0041

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2.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-10-21
УДК 004.083
Piskorsky V.P., Valeev R.A., Korolev D.V., Stolyankov Yu.V., Morgunov R.B.
TECHNOLOGIES OF MAGNETO-OPTICAL INFORMATION RECORDING IN THIN FILMS OF RARE-EARTH MAGNETICALLY SOFT ALLOYS. PART II. ULTRAFAST ALL OPTICAL SWITCHING OF MAGNETIZATION

This (second) part of the review touches on recent work in the field of the analysis of the magnetization of thin rare-earth films, which can be changed using a femtosecond laser. It is shown that instead of the traditional local heating technology, which lowers the threshold field for switching the magnetization of the film section, its magnetization reversal can be achieved by transmitting the angular momentum of the photons of the polarized laser light to the electron spins of the ferromagnet. This process occurs much faster than heating the ionic or electronic subsystems of a ferromagnet and can be used for ultrafast recording of information. At the same time, the well-known trilemma in magnetic recording technologies is overcome, which reduces to the contradiction between the requirement to minimize the size of recording elements while increasing their stability and decreasing the magnetization reversal field. The absence of the magnetic field necessary for the magnetization reversal of the films in the technology of fully optical magnetization reversal allows eliminating the requirement for the switching field and energy consumption from the trilemma. In the framework of this new technology, the switching of magnetization does not require a magnetic field, but occurs under the influence of light, and in such a short time that heating does not have time to occur. The main problems of the new ultrafast magnetic recording technology are listed. They consist in still low spatial resolution, limited by the diameter of the laser beam, which cannot be significantly less than the wavelength of light, and also in the "fatigue" of the material, which accumulates with the number of write-read cycles. The processes of formation of structural defects, oxidation of the material, and other causes leading to irreversible changes in thin films under the influence of femtosecond laser pulses are discussed in the review.

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3.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-22-30
УДК 669.018.29
Duyunova V.A., Leonov A.A., Molodtsov S.V.
VIAM'S CONTRIBUTION TO THE DEVELOPMENT OF LIGHT ALLOYS AND THE CORROSION CONTROL OF ROCKET AND SPACE TECHNOLOGY PRODUCTS

The purpose of this article was to highlight the contribution of the staff of the All-Russian Scientific Research Institute of Aviation Materials to the development of rocket and space technology, the institute’s participation in the development of materials for the space industry and the creation of a monument to the first man to enter the Earth’s orbit.

The article briefly discusses the events of the post-war formation of the space rocket activity of the USSR. Search and export of the development of the German engineer Werner von Braun related to the creation of the V-2 ballistic missile, the allies after the surrender of Germany during the Second World War; lag of the USSR in developed materials necessary for the space industry; arms race between the USA and the USSR. The creation of the first ballistic missiles and spacecraft.

The use of light metal alloys in rocket designs, such as the R-7 carrier rocket, and spacecraft such as «Sputnik-1», «Vostok», «Voskhod», «Soyuz», «Luna», «Venera» and «Mars», «Astron», in the «Oko» missile attack warning system, in the program for the creation of the reusable spacecraft «Energia–Buran», on the «Fregat» upper stage, and others. Reduction in the mass of space rocket structures as a result of the use of light alloys and ways to solve the problems of corrosion resistance of alloys in contact with aggressive components Tami propellant.

The main features and advantages of aluminum, magnesium, titanium and beryllium alloys, which are investigated and developed by the Institute, are listed. Examples of the use of alloys and technologies developed by VIAM employees in rocket and space technology products

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4.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-31-40
УДК 666.7
Rassokhina L.I., Bityutskaya O.N., Gamazina M.V., Kochetkov A.S.
FEATURES OF THE MANUFACTURING TECHNOLOGY OF HIGHLY REFRACTORY CERAMIC MOLDS FOR CASTINGS FROM γ-TiAl ALLOYS

The main properties of binders based on yttrium oxide Sol and aluminum oxide Sol for the manufacture of ceramic castings from γ-TiAl alloys were studied. Taking into account the studies of the main properties of these binders, the optimal mass ratios of the solid and liquid phase, technological parameters of the ceramic coating formation, and drying modes of the ceramic layer based on yttrium oxide Sol and aluminum oxide Sol were selected.

According to the developed technological parameters, ceramic forms of an analog of the blade with the use of water binders were made.

According to the developed technological modes, the model composition was removed from the inner cavity of the ceramic molds and high-temperature firing of the ceramic molds of the blade prototype was performed. The strength characteristics of ceramic witness samples made using yttrium oxide Sol were not determined due to the destruction of the samples during high-temperature firing.

Based on the results of visual inspection of the front layer of the inner cavity of the ceramic form (delamination and destruction) and the destruction of witness samples made with yttrium oxide Sol, it was decided to stop further work on the study of the main properties of this binder as unpromising.

According to the results of visual inspection of the inner cavity of the ceramic form of the prototype blade and the surface of the ceramic samples-witnesses, made using a binder Sol of aluminum oxide, no delamination of the facial layers was revealed. The strength characteristics of ceramic witness samples made using aluminum oxide Sol were determined, satisfactory results were obtained for strength at 20 and 1600°C, and it was decided to continue the research on the main properties of this Sol in order to develop a technology for manu

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5.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-41-49
УДК 669.018.95
Nyafkin A.N., Shavnev A.A., Kurbatkina E.I., Kosolapov D.V.
STUDYING THE EFFECT OF SILICON CARBIDE PARTICLE SIZE ON THE THERMAL COEFFICIENT LINEAR EXPANSION OF THE COMPOSITE MATERIAL BASED ON ALUMINUM ALLOY

This work is devoted to the development of technology for the fabrication and conduct of thermal expansion coefficient research of samples of a metal composite material based on an aluminum cast alloy of the Al-Mg-Cu-Si system with a content of 64 to 66 volume percent silicon carbide and various powder sizes with a grain size of 320–250 μm and a grain size of 125 –100 μm and grain size 63–50 μm. The measurements of the thermal expansion coefficient, in the temperature range from -100 to 400°C, of a composite material with different particle sizes. The average value of the thermal expansion coefficient at 20 ° С of a composite material based on silicon carbide powder with a grain size of 320–250 μm = 6.42 K-1 with a grain size of 125–100 μm = 7.38 K-1 with a grain size of 63–50 μm = 7.39 K -1. It was found that with an increase in the particle size of silicon carbide, the average value of the TEC decreases by 15–20% at 20 ° С, due to the low content of interphase boundaries of the heterogeneous structure of the composite, and the volume content of pores decreases. The MMC density was measured with a grain size of 320–250 μm = 3.027 g / cm3, with a grain size of 125–100 μm = 3.002 g / cm3 and a grain size of 63–50 μm = 3.001 g / cm3. The mass percentage of silicon carbide content in the material was calculated. The volume percent was calculated through the mass percentage taking into account the density of the metal composite material of the Al – SiC system and amounted to 65 ± 1% volume. An increase in the density of the preform can be achieved, as is known, due to a denser packing of the briquette by cold compaction, either using polyfraction powder mixtures or using both of these methods. Methods have been developed to obtain a composite material for the dete

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6.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-50-59
УДК 666.7
Zhitnyuk S.V., Sorokin O.Ju., Juravleva P.L.
SILICON CARBIDE CERAMICS OBTAINED BY SINTERING GRANULAR POWDER

Silicon carbide-based ceramics is a widely used material in various fields of industry and engineering, due to the high values of physical and mechanical characteristics. The most attractive properties of silicon carbide–based ceramics are considered to high strength, hardness, abrasion resistance, low coefficient of thermal expansion, the ability to bear significant power and thermal loads in aggressive environments. As is known, sintering of SIC ceramics is carried out at high temperatures reaching 2200°C, but it is practically impossible to obtain products with a complete absence of porosity, since silicon carbide has sufficiently low coefficients of surface and volume diffusion, and the temperature increase entails the decomposition of SiC into elemental components.

There are several methods designed to intensify the sintering processes of silicon carbide–based ceramics. However, a common approach is the use of fine and chemically pure powders with an average grain size of less than 1 μm in order to increase the surface area and, as a consequence, reduce the activation energy of diffusion processes. Since a number of difficulties arise during the pressing and transportation of fine powders (caking, dust pollution, poorly regulated bulk capacity), granular press powders, which are a system of spherical particles with identical physical and mechanical properties and size, are used in world practice.

The purpose of this work is to obtain silicon carbide–based ceramics with a high level of physical and mechanical properties by sintering fine granular powder without the use of oxide additives.

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7.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-60-71
УДК 669.018.95
Pripisnov Ya.A., Kurbatkina E.I., Kosolapov D.V.
THE MAIN TRENDS IN THE FIELD OF MACHINING AND JOINING Al-BASED MMCs (review)

The article deals with the features of modern methods of machining (technology of ultrasonic turning and milling) and obtaining permanent joints (high power diode laser welding, friction stir welding) on the example of AMCs.

Identified a number of problematic issues that arise during mechanical processing of highly filled AMCs. It is shown that the surface quality of the processed material depends on the cutting parameters (the speed of the main cutting motion, feed rate, depth of cut) and the geometry of the cutting tool. The abrasive nature of the particles of the hardening phase of high-filled AMCs, the volume fraction of which reaches 75%, significantly worsens the geometry of the cutting tool during cutting, which leads to uneven processing and a drop in the quality of the treated surface. The progressive method of shaping the surfaces of AMCs is the ultrasonic technology of turning or milling, which minimizes the contact of the hard-to-work material with the cutting tool, prevents bending, reduces the processing effort by up to 50%, which increases the surface quality to Ra

Analysis of foreign experience for the appropriateness of decisions Lee Schaeffer and Ernst-Merchant in processing AMCs and technologies, laser welding and soldering of highly filled backings of Al-SiC.

The table with estimates of technological methods of connection of AMCM received by different ways of production is resulted. The most recognized are friction stir welding and high power diode laser welding.

Friction welding with stirring has the following advantages: the absence of consumable electrodes, fluxes and protective medium, and due to intense plastic deformation, the destruction of the oxide film on the contact surface occurs, which contributes to the uniformity and strength of the welded

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8.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-72-80
УДК 66.045.3
Stepanova E.V., Zimichev A.M.
THERMAL INSULATION MATERIAL FOR CORDS MADE OF REFRACTORY OXIDE FIBERS

The work is devoted to production of heat-insulating materials from refractory fibers of aluminium oxide and silicon. Refractory fibres are prepared by sol-gel technology from highly viscous solutions based on precursors of water-soluble aluminium salts with addition of fibre-forming component to the solution. Methods of scanning differential calorimetry and gravimetric studies during heating have studied the processes of changing the composition and structure of oxide fibers. Mechanical properties of sealing cords with refractory fiber core were tested.

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9.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-81-90
УДК 629.7.023.222
Kondrashov E.K., Naidenov N.D.
EROSION RESISTANT PAINT COVERINGS OF AVIATION PURPOSE Part 1. Erosion resistant paint coatings based on epoxy and polyurethane films forming (review)

The problem of increasing the erosion resistance of coatings is relevant and is due to the continuous increase in the duration of operation of aircraft. The first part of the article presents the results of studies on the development of erosion-resistant epoxy, polyurethane and polyimide coatings.

The types of erosion damage and their classification are given, the types of installations for testing materials and coatings for resistance to gas abrasion wear are considered.

The design and operating modes of the Typhoon installation, which was used for a comparative assessment of the resistance of coatings to impact-abrasive wear, are considered in most detail. The collision speed of a coated abrasive particle selected for comparative tests, equal to 216 km/h (60 m/s), is characteristic of take-off and landing speeds, at which the impact of the abrasive particles on the coating most often occurs.

Equations are given that relate the intensity of erosion damage to the parameters of a two-phase flow, as well as an equation that relates the intensity of erosion failure to the strength and elongation of the coating itself.

When developing the enamel EP-586, it was shown that in the case of using unmodified epoxy oligomers with an increase in molecular weight from 400 to 2500, the erosion resistance of the coating increases by 1.5–2 times.

However, when developing the enamel EP-5236, it was shown that even higher erosion resistance can be achieved in the coating by using an epoxy oligomer with a molecular weight of 900 as a film former in case of its modification with rubber and using zinc oxide whiskers as a filler. The use of whiskers made it possible to develop the polyurethane enamel VE-62 sig

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10.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-91-100
УДК 669.018.24
Yakovlev N.O., Sedov O.V., Gulina I.V., Grinevich A.V.
FRACTOGRAPHIC STUDY OF BEARING STEEL FRACTURE

The article is devoted to the fractographic study of double fracture surfaces during standard tensile tests of samples of ball-bearing steel developed by FSUE «VIAM». Double destruction occurred simultaneously either in two fillets, or in the working part of the sample with the formation of a thin plate. Such an unexpected failure was never realized when testing structural alloys with ultimate strength characteristics. At the same time, the classical postulate of destruction does not reject the possibility of multiple destruction, since it states that destruction occurs in the zone of homogeneous material, when it reaches the ultimate stress-strain state. Multiple failure never occurred when testing samples of structural alloys due to the heterogeneity of the material structure. The heterogeneity of the alloy structure created a heterogeneity of the stress-strain state, which led to the localization of fracture. The main task in the development of ball-bearing steel is the formation of an extremely homogeneous carbide structure, which was achieved when creating a new steel for bearings. When tensile tests of standard samples in their working part creates a homogeneous stress-strain state and, therefore, the hypothesis of multiple fracture is not excluded. In contrast to the hypothesis of multiple destruction, a hypothesis was put forward about possible destruction by the spallation mechanism. Multiple fracture is characterized by the simultaneous formation of fracture surfaces and their fractographic identity. Fracture involves the separation in time of fracture from a static fracture and subsequent spallation. Fractographic studies of specimens destroyed under tension with the formation of one fracture surface, both in the fillet and in the working part of the specimen, were carried out. The study of fracture surfaces during double fracture of samples showed that they have different surface structures. In this case, the f

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11.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-101-108
УДК 543.51:669.245
Alekseev A.V., Yakimovitch P.V., Kvachonok I.K.
DETERMINATION OF IMPURITIES IN NICKEL BY ICP-MS

The content of impurities of 20 elements (P, Ti, V, Mn, Fe, Co, Cu, Zn, Ga, As, Se, Mo, Ag, Cd, Sn, Sb, Te, Tl, Pb, Bi) in nickel samples by inductively coupled plasma mass spectrometry (ICP-MS). The technique of sample dissolution and its preparation for analysis is given. Spectral interference was eliminated using the equations of mathematical correction, the use of a reaction-collision cell, and also by selecting the plasma power. The correctness of the results is confirmed by analysis of a certified standard sample of nickel alloy. The range of determined concentrations: 0,00002–0,0101% of the mass.

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12.
dx.doi.org/ 10.18577/2307-6046-2020-0-2-109-115
УДК 666.37
Babashov V.G., Maximov V.G., Basargin O.V.
TECHNIQUE OF DETERMINATION OF HIGH-SPEED SENSITIVITY OF TENSION DEFORMATION AT CREEP

One of the most important values characterizing the plastic flow of materials in the creep zone is the index of the speed sensitivity of the steady-state creep stress as the most used for experimental determination of the plastic flow mechanism. New method of fast and accurate determination of coefficient of speed sensitivity of strain stress at creep is proposed. Method is based on analysis of relaxation curves, i.e. dependence of reaction forces of tested samples on time in process of stress relaxation due to creep developing in them. Advantages of this technique are the absence of the need to directly determine differences of very small movements in the measurement of creep speed and the possibility of using loading schemes other than stretching. The only limitation in selecting a test scheme is the need to provide linearity for stress-strain communication. The latter makes it possible to use the bending test method for ceramic samples, which radically accelerates and reduces the cost of the experiment.

By this procedure, the high temperature relaxation curves of the mullite ceramic containing zirconia were analyzed. The material was obtained by sintering from co-precipitated oxide powders, test samples were cut from sintered blocks with a diamond wheel and treated by grinding with free abrasive using corundum powders. The tests were conducted according to the four-point bending scheme. In static bending, stress relaxation curves were obtained for the ceramic composite materials to be examined, which were generated in the material at a given constant strain value. Practical testing of the applicability of the new technique showed that the results obtained with it with high accuracy matched the values theoretically predicted for the most typical mechanisms of plastic flow.

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