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1.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-3-11
УДК 669.293
Bondarenko Yu.A., Bazyleva O.A., Raevskih A.N., Narskiy A.R.
RESEARCH ON THE CREATION OF A NEW HIGH-TEMPERATURE HEAT-RESISTANT MATRIX BASED ON INTERMETALLIC COMPOUNDS NiAl–Ni3Al

The paper presents the results of studies aimed at creating a new high-temperature and heat-resistant matrix based on intermetallic Ni3Al and NiAl. Solving the problem of creating new high-temperature materials is an urgent task for modern aviation gas turbine production. The analysis of the state diagrams made it possible to choose Ni3Al and NiAl intermetallic compounds as a material for research.

The strength, plasticity, density, heat resistance were evaluated on the samples of the basic compositions obtained under different crystallization conditions selected for the study. It is shown that high-gradient directional crystallization makes it possible to form a directed dendritic structure in the samples. The conducted microstructural and x-ray phase analysis allowed to establish that there are two main phases of Ni3Al and NiAl in the samples.

The studied samples after directional crystallization have higher strength and plasticity. The results show that intermetallic alloys of the Ni3Al-NiAl system can serve as a matrix in the creation of new high-temperature heat-resistant materials.

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2.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-12-19
УДК 621.762:669.24
Volkov A.M., Shestakova A.A., Bakradze M.M.
THE COMPARISON OF POWDER PRODUCED BY GAS ATOMIZATION AND BY PLASMA ROTATE ELECTRODE PROCESS IN THE POINT OF PRODUCTION DISK BILLETS FROM Ni-BASE SUPERALLOYS

Ni-base superalloy powder obtained either by atomizing or plasma rotate electrode process (PREP) are used for the production of disk billets for jet-engines. Powder particles produced via these methods differ by some parameters. The difference in presence of satellites and volume of fine fractions leads to difference in flowability and tap density which is essential to filling complex-shape cans. These features basically affect on performance of the process, but not on the structure and material properties. But occurrence closed argon porosity in atomizing powder allows to make solution heat treatment only at temperatures below solvus. Also differing size of MeC carbide particles involves to development of the special ageing regimes for material produced from accounted powder types. However, the structure and mechanical properties of the compacted material from these powder types would be different now. The mentioned differences challenge under development optimal technological routes of the production of disk billets from powder. For example billets from atomizing powder are desirable to produce by hot isostatic pressing (HIP) with subsequent hot or isothermal deformation. PREP powder could be used for direct HIP technology.

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3.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-20-27
УДК 669.245
Alekseev A.V., Rastegayeva G.Yu., Pahomkina T.N.
DETERMINATION OF SULFUR AND CARBON IN THE POWDER OF NICKEL ALLOYS

Currently, in the modern aviation industry and engine building, heat-resistant Nickel alloys are widely used, which experience huge thermal and power loads during operation. However, the manufacture of parts made of these materials, the metal part is removed with the use of different machine tools – milling, drilling, etc. These losses lead to waste of valuable alloy material, high cost of production, the emergence of a large number of waste. To solve this problem is possible with the use of additive technologies that allow to manufacture components and parts of any complex shape, reduce the time of establishing new production, reduce the cost of design and start-up.

An extremely important component in the success of the use of additive technologies is the quality of the initial powders of alloys, especially their chemical composition – the content of harmful impurities such as sulfur and carbon.

Classical methods of analysis are not applicable to the determination of sulfur and carbon because of their high complexity and time-consuming.  One of the most successfully used methods for determining sulfur and carbon in metals and alloys is the combustion of a gas analyzer in an induction furnace in an oxygen current, followed by detection in an infrared cell of the spectrometer. When using this method of analysis, it was necessary to choose a catalyst, a substance that accelerates and supports the combustion of metals in the furnace of the device, and also choose the mass of the sample sample.

Analysis was done of the powders of the three alloys ЭП648, ВПр50 and ВЖ159. It was found that the weight of the sample does not affect the results of the determination of oxygen and nitrogen, but to obtain the maximum analytical signal of the sample should be the greatest. The best results

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4.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-28-34
УДК 620.1:66.017
Mekalina I.V., Aizatulina M.K., Sentiourin E.G., Popov A.A.
FEATURES OF INFLUENCE OF ATMOSPHERIC FACTORS ON AVIATION ORGANIC GLASS

The development and creation of new models of aircraft constantly puts forward requirements for the improvement of structural materials used in aircraft construction. Promising brands of organic glass, planned to be used as aviation glazing, having the required characteristics at the time of installation on the product, often change the latter during operation, which necessitates a comprehensive study of the behavior of these materials under climatic influences, as one of the main components of operational factors.

The influence of atmospheric factors on the properties of polymethylmethacrylate and copolymer organic glasses after aging in the conditions of GCKI, Arizona (USA), Florida (USA) is investigated. The assessment of physical and mechanical, optical characteristics, "silver resistance", softening temperature of organic glasses after aging in different climatic zones. It is shown that polymethylmethacrylate Plexiglas of linear structure of CO-120A and AO-120 and partially crosslinked structure of CO-120C have high weather resistance, in comparison with copolymer Plexiglas of VOS-1 and VOS-2. Polymethylmethacrylate Plexiglas CO-120, AO-120 and CO-120C in an oriented and undirected state have high weather resistance in aging in conditions of GCKI, Arizona (USA), Florida (USA), and serial Plexiglas CO-120 and AO-120 also in the previous aging in Batumi, Cuba. The nature of reduction of physical-mechanical and optical properties of heat-resistant copolymer organic glasses VOS-1 and VOS-2 is similar to the behavior previously developed a serial of heat-resistant organic glasses (2-55, T2-55, E-2). When applying the heat-resistant copolymer organic glasses VOS-1 VOS-2 it is necessary to consider their tendency to yellowing, and photodegradation of the surface layer and to set the resource in accordance with the terms of the use of certain products, providing for the Shrouding of glazi

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5.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-35-44
УДК 678.8:620.1
Guseva M.A.
THE USE OF THE RHEOLOGICAL TESTS IN THE DEVELOPMENT OF POLYMERIC MATERIALS FOR VARIOUS PURPOSES

Currently, the development of new generation products uses a huge number of methods due to the expansion of the technical capabilities of research equipment. The study of rheological properties makes it possible to determine not only technological properties during polymer processing, structural and mechanical changes inside the material when exposed to the external environment, but also makes it possible to evaluate the future behavior of the material and its area of application at the design and component alignment stage. During the processing of polymeric materials, they are deformed, which is accompanied by structural transformations and a change in their rheological properties. Polymer materials (including compounds, blends and composite materials) are essentially thermoplastics, and the most important part of the process takes place in the molten state, they are characterized by rather complex behavior that needs a good description in order to understand and further optimize the processes.

This paper presents the results of rheological tests at the initial stages of the development of polymeric materials of various nature on a rotary rheometer AR2000ex. This device, due to its design features, allows to solve a wide range of tasks, makes it possible to work with liquids with low viscosity, polymer melts, materials with high hardness. Based on the results of studies of silicone binder, low molecular weight polytetrafluoroethylene (PTFE) with hydrophobic properties, as well as model compositions for the manufacture of melted models of gas turbine engine blades (GTE), the author shows the effect of various physical and technological factors (structure, temperature, phase transitions, nature matrix, filler) on the rheological behavior of the polymer material

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6.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-45-53
УДК 678.84
Prokofiev V.A., Sorokin O.Ju., Vaganova M.L., Lebedeva Yu.E.
HIGH-TEMPERATURE FUNCTIONALLY GRADED MATERIAL FABRICATED VIA REACTIVE ALLOY INFILTRATION

In recent years there have been a strong demand for ultra-high temperature ceramics (UHTCs) that can withstand extreme environments of high temperature, oxidation, stress, etc.

Reactive melt infiltration (RMI) of porous preforms is an effective approach to manufacture near-net shape components with complex geometries.

Tailoring of a preform pore structure, its reactivity with a melt can minimize the Si content.

The raw materials for manufacturing of initial porous samples were SiC and B4C powders, phenolic resin.

Processing route of  high-temperature functionally graded ceramics development consists of raw materials inspection, powder grinding, pressing and polymerization, heat treatment, mechanical machining,  reactive alloy infiltration, final mechanical machining.

To estimate the directions of possible reactions taking place during the RMI process, thermodynamic calculations were conducted by means of the software HSC Chemistry 5.

According to the thermodynamic calculations, forming of the HfB2 and  SiC  are supposed to be the most thermodynamically favorable reactions in SiC-B4C-C-HfSi2-Si system.

The thermodynamics calculations revealed and experimental data proved that Si-Hf(8,5at.%) melt can react with B4C and coke with the predominant formation of HfB2 и SiC at the peripheral region, SiC and B4C in the central region. Fully infiltrated SiC-HfB2-B4C-Si ceramic with homogeneous microstructure can be obtained at lower pressing.

It was shown that the SiC-HfB2-B4C-Si ceramics can be defined as a functionally graded material with low density and

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7.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-54-63
УДК 621.762.222
Efimochkin I.Yu., Kuzmina N.A., Grachshencov D.V., Svetlov I.L., Bobrovkiy A.P.
NIOBIUM SILICIDE SYNTHESIS BY SPARK PLASMA SINTERING OF COMPOSITE POWDERS

The possibility of the synthesis of niobium silicide Nb5Si3 by the spark plasma sintering (SPS) technique from a binary mixture of elemental powders of niobium and silicon obtained by mechanical alloying (MA) by two technological schemes is considered. The stability of the niobium silicide samples was investigated by heat treatment in vacuum at 1500 °C for 2, 4, 6, 8 and 10 hours.

The X-ray phase analysis of the synthesized niobium silicide samples was carried out; the microstructure of the samples was studied by scanning electron microscopy, and X-ray microanalysis were used to evaluate the elemental composition. The performed X-ray phase analysis of the synthesized samples, obtained by MA with subsequent hybrid SPS, demonstrated the possibility of obtaining the stable tetragonal α- Nb5Si3 threesilicide pentaniobium (according to synthesis scheme I) and hexagonal γ-Nb5Si3 threesilicide pentaniobium stabilized by interstitial carbon atoms (according to synthesis scheme II). The different solubility of carbon interstitial impurities in α- and γ-Nb5Si3 depends on structures features of the modifications. It should be noted that the synthesis process by the scheme II proceeds more thoroughly and non-reacted components of silicon and niobium powders remain in sample in changeless (unoxidized) state.

The stability study of synthesized niobium silicides samples showed that with an increase in heat treatment time at 1500 °C the microstructure of the samples does not undergo visible transformations. The stability of the phase composition during the heat treatment process is confirmed by X-ray phase analysis data.

Now therefore, the change the technological conditions of obtaining of Nb5Si3, which determines the mechanical properties of the Nb-Si composite, allows the cont

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8.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-64-73
УДК 669.018.44
Movenko D.A., Medvedev P.N., Smirnov A.A.
STUDY OF CHANGES IN THE HEAT-RESISTANT ALLOY COATING STRUCTURE AFTER HEAT RESISTANCE TESTS

The material of the heat-resistant alloy with a heat-shielding coating (Zr – Gd – Y – O) + (Al – Ni – Y) + (Ni – Cr – Al – Ta – Re – Y – Hf) in the state after vacuum annealing at 1050 ° C / 3 h and after testing for isothermal heat resistance of 1200 ° C / 100 h was investigated. After annealing, the coating material revealed zones of interaction between its components and the substrate, formed due to their mutual diffusion. Using the data on the elemental composition of the coating, as well as the phase diagrams of the Al – Ni, Ni – Cr, Al – Ni – Cr systems, the structural components of the coating were identified. The ceramic layer consists of zirconium oxide stabilized with yttrium and gadolinium oxides. The upper layer is mainly represented by the β-phase. The bottom layer consists of the γʹ-phase. Structural components based on the γʹ, β and α phases were found in the zone of their interaction. The zone of interaction between the bottom layer and the substrate consists of the γʹ-phase and particles based on the α-phase. According to the results of the accumulation of the elemental composition profile over the thickness of the coating, it was concluded that changes in the content of nickel, aluminum, and chromium have a gradient character, which indicates incomplete diffusion processes. As a result of high-temperature exposure in the process of testing for heat resistance, the ceramic layer is locally destroyed. An oxide layer forms on the surface of the heat-resistant layer. The material of the heat-resistant layer loses its layer structure. Several factors indicate an increase in diffusion processes. It was found that the elemental composition of the layer is aligned in depth, and the size of the structural components increases. This, first of all, concerns the grains of a solid solution

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9.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-74-85
УДК 620.197:620.193.2
Kuznetsova V.A., Shapovalov G.G.
TENDENCIES OF DEVELOPMENT OF THE EROSION-RESISTANT COATINGS (review)

It is known that the responsible details of flight vehicles subject to action of hostile environment need additional protection. As such protection different types of coatings, including paint and varnish are exploited. One of types of influence to constructional surfaces is collision with different heterogeneous environments which are present at operational zone, it can be the solid and liquid particles distributed in air in definitely way. Such influence leads to erosion of constructional materials and finally to their destruction. The coverings resistant to similar destructions, are urged to provide long service of the flight vehicles responsible elements.

In this work the analysis of development and the main trends of development of erosion resistant coatings around the world throughout long time of the solution of problem of ensuring necessary erosion resistance is carried out. During the analysis the main trends in which are revealed the hard work is conducted: the first is increasing of erosion resistance and the second is high adhesive strength of coatings to protected surface. The increase of erosion resistance is reached at the expense of optimization of composition and structure of coatings, in particular at combination of properties of reinforcing fillers to certain characteristics of polymeric matrix. Possible variations of used polymeric and inorganic compositions are considered and given in this work and also the way of achievement of required properties are also discussed.

During the analysis of the last achievements the main groups of technologies and structures of erosion resistent coatings are revealed: coatings on the basis of elastomer; coatings on the basis of the thermosetting organic and inorganic binders; the multilayer (complex) coatings consisting from inorganic (aluminophosphate, silica-alumina binder) on which p

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10.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-86-92
УДК 620.1
Kosarina E.I., Generalov A.S., Demidov A.A.
QUESTIONS OF X-RAY NON-DESTRUCTIVE TESTING IN RUSSIAN STATE STANDARDIZATION SYSTEM

The current system of state standards for X-ray nondestructive testing has a strict hierarchical structure that determines application area of state standard, industry standard, enterprise standard. The ongoing integration had affected the system standards including standards governing X-ray non-destructive testing. Some standards from the ISO system translated into Russian received the status of GOST R ISO. For some other standards, particularly ISO 17636 it is the nearest future. The process is quite intense. In the proposed publication, the authors raise the question of the feasibility of automatic implementation of ISO standards in the Russian system of standardization. A comparative analysis of the regulations of GOST and ISO systems in X-ray NDT, the description of which is given in this article, shows that there are no obvious contradictions of the main provisions in this documents. However, we believe that it is necessary to adopt ISO system completely and exclude GOST, or Supplement GOST system with more stringent ISO requirements that do not contradict GOST, and in no case to prevent a combination of conflicting provisions of GOST and ISO. Thus it is necessary to keep the strict hierarchical structure defining spaces of state standard, industry standard, enterprise standard.

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11.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-93-100
УДК 620.193.4:620.193.5
Medvedev I.M., Nikitin Ya.Yu., Puzanov A.I., Laptev A.B.
HOT CORROSION TESTING METHODS FOR HIGH-TEMPERATURE ALLOYS (review)

Hot corrosion of high temperature alloys, used in modern gas turbine engine, is still a problem due to harsh service conditions, inability to apply protective coatings to every piece of engine and imperfect hot corrosion resistance of alloys. Therefore the durability of modern gas turbine engines is heavily influenced by corrosion rate during service life and by decrease of mechanical properties due to corrosion damage.

To this day there no industrial unified approach to evaluation of hot temperature corrosion resistance of high temperature alloys. The aim of a current article is to provide a review of the recent experience in field of hot corrosion testing of superalloys.

The most common methods to evaluate hot corrosion of superalloys are burner rig, deposit recoat method or electrochemical testing. Most common testing method is deposit recoat and further heating in ovens. 75% Na2SO4 + 25% NaCl is the most common corrosive solution for this type of testing. Test temperatures range from 650 to 950 ºC. Burner rig testing provides the best reproduction of service life conditions, but these tests are the most expensive. The main criterion for assessment of alloys’ resistance to hot corrosion is gravimetry, which is used to measure weight loss and corrosion depth. Many researchers have also investigated the influence of hot corrosion on mechanical properties of high temperature alloys. High temperature service life estimation methods with respect to corrosion damage due to high temperature corrosion are not yet published in Russian and international papers.

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12.
dx.doi.org/ 10.18577/2307-6046-2018-0-11-101-110
УДК 620.179:678.747.2
Istyagin S.E., Postnov V.I.
ABOUT INCREASE ACCURACY OF CORRELATION DEPENDENCE PARAMETERS NONDESTRUCTIVE CONTROL AT DIAGNOSTICS OF PROPERTIES COAL PLASTICS

One of the ways to use non-destructive testing in the theory of reliability is the indirect measurement of mechanical characteristics before and after the selected period of operation. With non-destructive testing (NC), it is necessary to measure such a parameter, which would be an adequate measure of the stresses arising in the material. To improve the accuracy of the correlation equations, it is necessary to investigate witness samples with a sufficient variation of the elastic-strength properties. It is possible to determine the necessary level of variation for constructing a regression equation only by an experimental method using statistical analysis.

For the manufacture of samples with natural technological defects, between the layers of the prepreg KMU-11TR were laid layers of dry charcoal UT-900 in the ratio of 50% and 30% of the total number of layers. According to the results of the analysis with 50% dry filler, the porosity increases four times relative to the porosity at 30% and is 6.06%. This ensures the level of variation of mechanical characteristics due to the creation of defects that affect the informative control parameter Units.

The object of the study of mechanical characteristics were CFRP samples KMU-11TR with dimensions of 250 × 12 × 2 mm, intended for input control of tensile strength. After measuring the dynamic modulus of elasticity, destructive tests were carried out to determine the tensile strength.

Before you use any experimental data, it is necessary to conduct a mathematical analysis of the resulting array. Through analysis, the possibility of applying the array for further work is verified. Taking the results at a 30% dry filler content unreliable according to the statistical analysis criteria, the equations of the dependencies of tensile strength (&a

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