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1. 10.18577/2307-6046-2021-0-1-3-12
УДК 669.17:621.791
Ospennikova O.G., Afanasiev-Khodykin A.N., Galushka I.A.

The article presents the results of a study of the microstructure of a brazed joint of an opposite combination of nickel heat-resistant alloys of a casting single-crystal alloy VKNA-25, a heat-resistant wrought alloy EP975, made with a complex alloyed solder on a nickel base VPr 56.

A gradient microstructure formed during the soldering process, consisting of five main zones, differing from each other in terms of the formation mechanism and chemical composition. So, a brazed seam is a combination of a solid solution layer (γ+γʹ) on the border with VKNA-25, framed from the side of the soldered seam with a eutectic (γ+γʹ primary); solid solution of γ–γʹ solder, and an interlayer of solid solution (γ+γʹ) at the boundary with EP975, framed from the side of the centre of the solder joint with eutectic (γ+γʹ primary).

The analysis of the chemical composition of phases at different times of homogenization treatment shows that the chemical composition of the phases in different diagrams practically does not change a heat treatment, the main changes in the microstructure are associated with a change in the size (width) of the zones.

To assess the dependencies, the values of the main structural components were carried out on panoramic photographs of the soldered images obtained with different heat treatment and made with a variable gap. As a result of the study, the main regularities of the change in the microstructure of the soldered joint during heat treatment were established, and the current various empirical formula was derived and tested, which determines the duration of heat treatment, special for obtaining the optimal microstructure of the brazed joint, for the values of assembly gaps.

As a result of the research done, on sampl

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2. 10.18577/2307-6046-2021-0-1-13-22
УДК 669.046.516.2
Krylov S.А., Egorov E.V., Makarov А.А., Druzhnov M.A.

The relevance of the article is due to the fact that currently the rise in prices for the products of metallurgical plants is quite high, given the global fundamental prospects.  The article discusses issues related to the production of new charge materials that can partially or completely replace traditional charge materials for the production of heat-resistant nickel steels and alloys, in order to curb the rise in prices for the final product.

The article reflects the main features and parameters of the smelting process, contains the calculation of the assimilation of alloying elements and a diagram showing the comparison of the assimilation of the elements W, Mo and Cr, depending on the method of introduction.  The data on the chemical composition of the ligatures are given, as well as their arbitration assessment is shown.

In this work, the macro- and microstructure of alloys: EP742-ID, EP708-VD, EI698-VD, EP202-VD were investigated.  A qualitative assessment of non-metallic inclusions is given and a diagram of the content of gas impurities in ingots of experimental composition and ingots of serial production is presented.  The article also outlines the development of a method for alloying with molybdenum and tungsten ligatures, a description of the experiment and the results obtained.

Mechanical tests of experimental melts are carried out and data on the impact toughness of EP742-ID alloy obtained with the use of molybdenum-chromium master alloy are presented in order to assess the effect of the content of gas impurities on the long-term strength with maximum load, as well as at elevated temperatures.

At the end of the article, it is summarized that alloys obtained using molybdenum-chromium and tungsten-chromium master alloys in heat-resistant alloys and steels ful

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3. 10.18577/2307-6046-2021-0-1-23-33
УДК 620.193
Sviridov A.V., Afanasiev-Khodykin A.N., Galushka I.A.

According to the research results, it was found that the type of brazing alloy has a significant effect on the type and mechanism of formation of corrosion damage to brazed joints not only directly in the brazed seam, but also in the near-weld zone. The effect of brazing alloy is especially strong on low-alloy steels with a low chromium content.

In particular, on steels EP410 and EI961, VPr4 brazing alloy under conditions of intense corrosion action promotes the occurrence of contact-crevice corrosion at the brazing alloy-base material interface. At the same time, corrosion occurs intensively in EP410 and EI961 steels, practically without affecting the brazed seam itself.

Brazing alloy VPr50 under the same conditions behaves not so unambiguously. The influence of the brazing alloy VPr50 on the development of corrosion damage to EP410 steel was not found. And on the EI961 steel, the VPr50 Brazing alloy, possibly, provokes the appearance of corrosion centers near the brazed joint. In this case, unlike VPr4 brazing alloy, VPr50 brazing alloy apparently does not participate in the further development of corrosion damage, since further corrosion is of purely crevice nature and spreads in steel EI961 without spatial orientation of the relative position of the brazed joint made with VPr50 brazing alloy.

Both investigated brazing alloys (VPr4 and VPr50) have no corrosive effect on steel 12Kh18N10T, which has the highest corrosion resistance among the studied steels. According to the research results, VPr50 brazing alloy possesses corrosion resistance at the level of steel 12X18H10T, since No corrosion damage was found on the base material or on the fillet of the brazed joint. And the VPr4 brazing alloy in this system has lower corrosion resistance as compared to steel 12

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4. 10.18577/2307-6046-2021-0-1-34-42
УДК 666.7
Rassokhina L.I., Bityutskaya O.N., Gamazina M.V., Avdeev V.V.

The paper analyzes scientific and technical information in the field of creating ceramic rods based on fused quartz for casting turbine blades from heat-resistant Nickel alloys, according to which it is established that the composition of ceramic rods, in addition to the base (fused quartz), requires the introduction of mineralizers and thermally stable additives that activate sintering, suppress shrinkage and the formation of macro-cracks in ceramic rods during firing. As a result of the analysis and experience of FSUE «VIAM», materials (various fractions of fused quartz, high-performance sintering additives and a thermoplasticizer) and experimental compositions with different ratios of fused quartz of various fractions and a thermoplasticizer were selected. Technological parameters of manufacturing ceramic rods based on fused quartz are studied: pressing parameters (pressing force, core mass temperature, holding time), parameters of high-temperature firing (working temperature of firing, holding time of rods during firing, speed of their heating and cooling during firing). The properties of experimental samples of ceramic rods of selected compositions made according to the developed technological parameters are studied.

Based on the research results, the optimal composition (fused quartz powders, calcium stearate, aluminium oxide, β-Sialon) and technological parameters for the production of rod mass (temperature and production time) and ceramic rods (parameters of pressing and high-temperature firing) were selected. Wax models of blades were pressed using ceramic rods, model blocks were assembled, ceramic molds were made, and blade castings were filled in.

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5. 10.18577/2307-6046-2021-0-1-43-53
УДК 678.8
Gunyaeva A.G., Kurnosov A.O., Gulyaev I.N.

The continuous development of the aviation industry creates a need for the use of new materials with improved properties for high-tech products. It becomes necessary not only to bring the performance indicators of materials to the maximum possible values, but also to ensure a high level of their preservation in the widest temperature range.

The creation of advanced aircraft technology and aircraft engines requires expanding the range of high-temperature materials and developing new modern structural PCM, which, along with high strength, increased thermal-oxidative stability, reduced porosity, ensuring the maximum level of preservation of strength characteristics when operating at elevated temperatures.

FSUE «VIAM» has many years of experience in the development of this class of PCM – the first work on the creation of carbon fiber with an operating temperature of more than 250 °C was obtained back in the 1970s and 1980s. VIAM Specialists continue to conduct research in the development of compositions and technologies for obtaining a new generation of PCM, without stopping there. Current trends in the development of new propulsion systems imply an expansion of the application areas of polymer composite materials. For example, for use in the construction of heat-loaded elements of the engine nacelle and the cold circuit of the engine, polymer composite materials that are resistant to high temperatures are required.

The most important task of aviation materials science is to create heat-resistant polymer composite materials – high-temperature carbon fiber and fiberglass. An important factor is the almost complete absence of domestic materials-analogues that are competitive with imported ones.

The article provide

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6. 10.18577/2307-6046-2021-0-1-54-65
УДК 678.8
Nacharkina A.V., Zelenina I.V., Valueva M.I., Voronina O.G.

The development of PCMs that are resistant to the effects of elevated temperatures is an urgent task of modern materials science.

At the same time, an important condition is the creation of a monolithic system «reinforcing filler–polymer matrix», which ensures the implementation of the maximum level of PCM properties. The formation of the interfacial layer may be directly influenced by the apparet present on the surface of the fibers.

For high-temperature carbon plastics, an apparet applied to improve weaving has a negative effect, since at curing temperatures of high-temperature carbon plastics above 250˚С, the process of destruction of the apparet begins, leading to pore formation in the polymer matrix, and as a result, the properties of carbon plastics deteriorate.

The article deals with the influence of the appret deposited on carbon fiber on the characteristics of carbon plastics obtained from it.

During the work, carbon plastics were obtained based on a heat-resistant thermosetting phthalonitrile binder and carbon bulk-reinforced woven preforms. The use of preforms significantly reduces the labor intensity of making structures from PCM, as a result of which the creation of materials based on them is today a promising direction. Textile processing of unadjusted carbon fibers into preforms is impossible.

From the point of view of the subsequent application of the preform to produce high temperature carbon plastics, various methods of removing the apparet have been discussed. Using modern test equipment and standardized test methods, the properties of carbon plastics from preforms with and without an apparet, including tensile, compression, bending, shear strengths, were investigated. The influence of heat aging and moisture saturat

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7. 10.18577/2307-6046-2021-0-1-66-76
УДК 678.8
Postnov V.I., Satdinov R.A., Makrushin K.V., Ivanov M.S.

This article is devoted to the design and technological development of flexible pipelines made of polymer composite materials (PCM) of air conditioning systems (ACS).

The article analyzes various types of flexible a result, a number of specific parameters were established that depend on the design of a particular flexible pipeline. These parameters include maintaining a constant cross-section of the pipeline when bending at an angle of 90° or more, a certain type of folds when bending, choosing the optimal step for winding the stiffness spiral, ensuring tightness and flexibility of the joint of the pipeline shell, and making the optimal design of elastic cuffs.

Information is given that the FSUE VIAM has developed and tested the design and developed a method for manufacturing a flexible pipeline made of PCM with an elastic shell reinforced with fabric. On top of the shell, a spiral of stiffness is glued on elastic glue from a cord consisting of threads, impregnated with a solution of a thermosetting binder, cured after gluing. The concentration of the binder solution is selected so as to exclude brittle destruction of the cord when it is bent and give it elastic properties. At the ends of the shell there are cuffs for connecting flexible pipelines with other elements of the ACS. All materials included in this flexible pipeline are manufactured according to domestic standards, are non-flammable or self-extinguishing. Compliance of this flexible pipeline design with the AP-25 fire safety requirements has been confirmed by tests.

In order to obtain flexible pipelines of any required length, the technology of «splicing» individual pipeline fragments on collapsible mandrels has been developed, by connecting them with elastic hermetic couplings made of organosilicon sealant vulcanized at ambient tempera

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8. 10.18577/2307-6046-2021-0-1-77-84
УДК 678.83
Kan A.Ch., Zhelezina G.F., Solovjova N.A.

The work is devoted to the study of the possibility of using protective screens made of aramid organoplastics to increase the bird resistance of elements of aircraft structures, in particular aircraft flaps with carbon fiber sheaths. The protective screen is a two-layer structure. The inner layer is made of impact-resistant organoplastics, the outer layer is made of sealed organoplastics that provide protection from water, atmospheric moisture and other climatic factors. Sheets of organoplastics are glued together and the carbon fiber covering of the flap with phenolic rubber and epoxy glue.

Constructively similar flap samples were used for testing. The samples are three-layer honeycomb panels of a typical design, 800×800 mm in size, 40 mm high with two carbon fiber sheaths. The samples were subjected to tests for resistance to mechanical shock (falling of a 9 kg load from a height of 30 m) simulating a collision with a bird in the initial state and in the presence of protective screens made of organoplastics.

The nature of destruction of carbon fiber sheaths unprotected and protected by screens made of organoplastics is studied. As a result of the impact on the unprotected sample, the upper carbon fiber skin of the three-layer honeycomb panel was destroyed. Under the destroyed carbon fiber cladding, there is a crumpling of metal honeycombs. As a result of the impact on the sample flap with a protective screen, there is no destruction of the front screen made of organoplastics, there are no visual stratifications in the impact zone, and the honeycomb is crumpled slightly.

The results of tests of structurally similar aircraft flap samples confirm the effectiveness of using protective screens made of organoplastics to ensure the resistance of structural elements to mechanical shock, simulating a collision with a large bir

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9. 10.18577/2307-6046-2021-0-1-85-96
УДК 678.8
Goncharov V.A., Usacheva M.N., Khrulkov A.V.

A propeller shaft is required to transfer power from the engine to the axle and drive wheel in a rear wheel drive vehicle. This highly loaded part is usually made of steel or aluminum, as well as composites.

Compared to metal drive shafts, CFRP drive shafts have many advantages: transmission efficiency, increased comfort, reduced emissions, reduced weight, noise and vibration.

The main thing that attracts engineers to use composites in drive shafts is that composites provide the ability to increase the length of the shaft while maintaining or even improving mechanical performance.

By adjusting the resin composition and fiber reinforcement pattern, the mechanical properties of the transmission shaft can be improved. By changing the winding angle, the elastic modulus and natural frequency of the shaft can be increased. The angle of inclination of the winding of the layers affects the distribution of the load, which leads to a difference in the values of natural frequencies. Fiber angle orientation and stacking sequence have a large impact on bending moment as well as dynamic performance.

The fiber orientation angle has a great influence on the natural frequency of the drive shaft. To increase the natural frequency and modulus of elasticity in the longitudinal direction of the shaft, the fibers must be oriented at 0°.

The question of modifying the matrix should be solved in such a way as to ensure the stable operation of all layers both in torsion and shock loads when the rotation speeds change.

The stacking sequence affects fatigue resistance. It is best to lay layers with ±45° fiber orientation around the inner surface of the torque tube.

Due to the high cost of comp

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10. 10.18577/2307-6046-2021-0-1-97-104
УДК 629.7.023.226
Istomin A.V., Kolyshev S.G.

With the growth of industrial production, the need for an increase in the production of heat-shielding materials increases. With the increase in production capacity, the amount of waste inevitably increases. Heat-shielding materials based on fibers of aluminum oxide and zirconium, capable of operating for a long time in an oxidizing atmosphere at high temperatures, are becoming more widespread. High-temperature thermal protection is expensive, which has prompted the development of methods for recycling and reusing such materials.

Effective use of secondary raw materials requires a multilevel, efficient set of methods for sorting materials. Currently, the separation of materials is carried out in several ways: separate collection of waste; manual waste separation; separation of waste by density (flotation and aeroseparation); electrostatic separation methods; IR spectroscopy for waste identification and separation; ultrasonic and X-ray waste separation.

After analyzing the technological process of obtaining high-temperature fiber of zirconium dioxide and heat-shielding materials based on it, implemented at «VIAM», the main stages of the formation of fibrous production wastes were identified. The paper proposes a method for processing substandard fiber into high-density heat-resistant ceramic materials.

The production of ceramic material was carried out by pressing the crushed zirconium dioxide fiber with subsequent heat treatment. The samples obtained had a fibrous structure, had a three-point bending strength of the order of 30–32 MPa and resistance to thermal shock in comparison with samples obtained from powdered raw materials. Based on the studies carried out, it can be concluded that heat-resistant products made from production wastes can be used as furnace lining, heat-resistant substrates and container

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11. 10.18577/2307-6046-2021-0-1-105-113
УДК 621.7.024.4
Kravchenko N.G., Kozlov I.A., Shchekin V.K., Efimova E.A.

During operation of gas turbine engines oil particles, aerosols of sea salts, particles of dust, soil and organic matter contained in the air can settle into the flow path of the engine including on the turbine blades. These contaminants can lead to significant changes in the thermodynamic characteristics of the gas turbine engine, and under the condition of prolonged contact of salts with parts, both during operation and during interruptions in operation, they can cause corrosion damage of parts.

Regular flushing with detergent solution is the best way to clean your engine. This procedure is quite simple and quick, in which a flushing solution or distilled water is supplied under pressure to the engine's cylinder head by means of a special flushing unit.

The tasks were to analyze the basic requirements for detergents, to determine the main types of components that make up the detergent, to analyze existing detergent compositions.

It has been established that modern development trends in the field of compositions of detergents and degreasing agents for removing various types of contaminants are aimed at improving the quality of cleaning metal surfaces; versatility of detergents in relation to a wide range of contaminants, that is, the ability to remove several types of contaminants; providing additional protection of metals from corrosion after washing. Also an important place is given to more environmentally friendly and fire-safe products. In particular, non-ionic surfactants are used in production and flammable solvents are avoided.

For the aviation industry, technical detergents are of great interest today, which can be used during operation for regular flushing of the flow path without disassembling the engine and removing the corresponding parts for cleaning. For this, in addition to

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12. 10.18577/2307-6046-2021-0-1-114-122
УДК 620.1
Laptev A.B., Pavlov M.R., Novikov A.A., Slavin A.V.

The review analyzes publications on climate testing of materials in various industries to ensure safe operation of equipment, structures and buildings. Based on the analysis of world experience in conducting climate tests, the main development trends related to the creation and application of new materials, new forms of application of known materials, compatibility of materials, modeling of loading cycles to simulate real operating conditions, acceleration of climate tests, the impact of climate factor gradients on materials, taking into account the level of climate factors in a specific area with minimal resolution, climate change, new methods for assessing the climate resistance of new materials are determined, biological factors of influence.

In the first part of the review, the directions of development of climate testing of new materials, such as nanomodified polymer composite materials, building thermal insulation materials based on both organic and inorganic fibers, polymer composite materials with shape memory, encapsulated polymer materials, as well as materials for building radiation cooling panels and lithium-ion batteries, are identified.

Climate testing of these new materials should be carried out taking into account the features of their application, economic indicators of use and utilization, using methods of mathematical modeling of climate impact processes. This will allow us to take into account the impact of climate factors not only on the basis of past long-term atmospheric parameters, but also to predict the behavior of materials and structures in General under climate change. It is shown that to assess and predict changes in properties of materials over a long operating life tests of materials are required to conduct accelerated methods of building mathematical models of processes of degradation of their properties under the given climatic<

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