Articles

 


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1.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-3-14
УДК 621.791
Kablov E.N., Antipov V.V., Sviridov A.V., Gribkov М.S.
FEATURES OF ELECTRON BEAM WELDING OF HEAT-RESISTANT ALLOYS EI698-VD AND EP718-ID WITH STEEL 45

Тests were conducted to determine the mechanical properties of welded joints at room and elevated temperatures.

For testing, samples were cut from welded annular billets of the connection of dissimilar materials - disks from alloys EI698, EP718 with steel 45 welded at the optimum mode. When choosing the optimal ELS modes, the welding speed, working distance, beam current strength, and focusing current were varied to obtain defect-free joints.

Non-destructive ultrasonic and capillary testing of welded joints from heat-resistant nickel alloys EI698, EP718 with steel 45 was carried out, which showed the absence of defects throughout the weld and confirmed the suitability of the samples for further research and testing

From the results of measuring the microhardness of the welded joint, it follows that the minimum hardness is observed in steel 45. When approaching the weld from the steel side, the hardness increases. In general, the change in hardness along the weld width is uniform without obvious jumps in values, which indirectly confirms the absence of brittle phases.

Metallographic studies showed that no unacceptable defects in welded joints were found on the macro section. On the microsection, the boundary between steel 45 and the weld is clearly visible. Alloys EI698, EP718 and steel 45 have similar melting points, but due to the lower thermal conductivity of the nickel alloy, its melting occurs predominantly, despite the beam shifting toward steel.

Analysis of the results of determining the mechanical characteristics of welded joints made it possible to choose a welding mode that provides a strength level of welded joints of more than 1 of the strength of the base metal of steel 45, which indicates a high quality of the welded joint.

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2.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-15-26
УДК 678.073
Pykhtin A.A., Sorokin A.E., Kraev I.D., Voronov V.A.
THE CHOICE THE OF THE THERMOSETTING BINDER COMPOSITION MODIFIED BY ACTIVE NANOPARTICLES OF LSNO CERAMICS, FOR IMPREGNATION OF THERMOPLASTIC TEMPLATES OBTAINED BY FDM-PRINTING

This paper presents the main results of research work devoted to the choice of the composition of a polymer nanocomposite modified with nanoparticles of active ceramic La15/8Sr1/8NiO4  for impregnation of thermoplastic templates obtained by FDM printing. The synthesis of LNSO by the ceramic method was carried out and its structure was determined using x-ray diffraction. Its technological and functional properties are investigated. The effect of temperature on the viscosity of systems based on various polymer matrices (ED 22, Laprol 2002D, SKTN-A) was determined. A study was made of the microstructure of cured compositions based on the studied polymer matrices and LNSO particles. It was found that the best distribution of ceramic nanoparticles of the composition La15/8Sr1/8NiO4 is achieved by introducing it into ED-22. It is shown that the highest physical and mechanical values are achieved when using, as a polymer matrix, an epoxy oligomer of the ED-22 brand. Test experiments were carried out on high-energy grinding of ceramics (complex nickelate) to obtain a stable dispersion of LSNO nanoparticles. The optimal polymer matrix for the binder was selected (epoxy oligomer ED-22). The effect of surfactants on rheological properties was investigated and the optimal surfactant (BYK W9010) and its concentration (0.5 wt%) were determined to obtain a stable dispersion of LNSO ceramics in epoxy resin as a “discrete phase” of a two-matrix material in a polymer matrix. The effect of stabilizers on the rheological properties of dispersions of LNSO in epoxy resin was evaluated. In the course of the work, measurements were made of the electrophysical characteristics of the filled thermosets. We found that when particles of LNSO ceramics are introduced into various polymer matrices (ED 22, Laprol 2002D, SKTN-A) in the concentration range from 5 to 90 wt.%, The resultin

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3.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-27-34
УДК 665.939.5
Isaev A.Yu., Pavlyuk B.Ph., Petrova A.P., Lukina N.F., Balabanova O.S.
EFFECT OF MODIFICATION OF COLD CURED EPOXY ADHESIVES WITH ELASTOMERS ON THE RESOURCE STRENGTH OF ADHESIVE JOINTS

Comparative data on characteristics of the adhesive joints executed by epoxy adhesive of cold curing VK-9 (not modified) and VK-27 (modified by rubber) are provided. It is shown that updating of epoxy adhesive of cold curing by rubber leads to increase of strength, deformation and resource characteristics of glued joints, however heat resistance of adhesive joints decreases. Comparison of properties of the adhesive joints executed by adhesives VK-9 and VK-27 is given, at influence of loadings, temperatures, humidity and other factors.

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4.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-35-43
УДК 678.026
Venediktova M.A., Petrova A.P., Barbotko S.L., Bryk Ya. А.
APPLICATION OF NEW ENVIRONMENTALLY FRIENDLY ORGANOPHOSPHORUS FLAME RETARDANTS IN THE COMPOSITION OF HEAT-PROTECTIVE PUTTY

The modern industry makes special demands to the solution of problems of thermal protection of the equipment and designs aviation, rocketry, transport, objects of capital construction and etc.

Simple in processing and effective at protection against thermal, aerodynamic influence and erosive destruction ablative evaporated polymeric heat-protective materials are the most technological.

There is thermal protection of elements of equipment in which are applied the simple and combined systems: with gas-dynamic and hydrodynamic cooling, heat-absorbing, heat-disseminating, with expense and without weight expense, reusable, one-time (ablation).

Cessation of production of number of initial components, restriction of production of ecologically hazardous substances, and also big arrival on the Russian market  of import materials of similar assignment to have led to decrease in production of number of heat-protective materials. 

The heat-protective material are widely used in modern equipment, therefore recovery of production of components which has been lost and replacement of ecologically dangerous products by the safe products has special relevance. For the solution of this problem there was need of development of synthesis method and technology receiving ecologically safe phosphorus fire-retarding agents instead of the used. This task has been successfully solved by Federal State Unitary Enterprise «State Research Institute of Organic Chemistry and Technology».

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5.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-44-51
УДК 678.8678.8
Kolobkov A.S.
INFLUENCE OF NON-WOVEN THERMOPLASTIC MATERIALS ON THE STRENGTH OF LAYERED POLYMER COMPOSITE MATERIALS (review)

Interest in polymer composite materials does not weaken over time and its application in various fields increases due to outstanding indicators of specific strength and specific modulus of elasticity. At the same time, there is still a problem that is not completely solved, which is mostly related to carbon fiber, it is low resistance to shock loads and relatively low values of interlayer strength.

The consequence of this problem is the study of regularities and search for solutions aimed at increasing the interlayer strength of carbon fiber. To date, the main approach is to introduce various agents into the polymer matrix that provide energy dissipation during impact, among these strengthening agents are nanoparticles, rubbers, and high-temperature thermoplastics. In this paper, we consider a method for increasing the impact characteristics and interlayer strength of carbon fiber associated with the use of nanofiber veils, which are laid between layers of reinforcing filler in the production of layered materials. Studies related to the use of nanofiber veils made of various thermoplastics, such as, for example, polyethersulfone, which is soluble in an epoxy polymer matrix, and polyamide-6,6 – insoluble in an epoxy binder, are considered.

Based on the results of the considered works, it can be concluded that this approach to the use of nanofiber veils gives a positive result, which provides an increase in both the impact strength of carbon fiber and the increase in the interlayer strength. However, it should be noted that a significant increase in the above characteristics of carbon fiber by 20–40% is due to the fact that experiments use pure epoxy binders without strengthening components. The results of comparison of carbon fiber reinforced with nanofiber veils and polymer binders with strengthening components are not presented in the considered wor

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6.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-52-60
УДК 669.018.95
Serpova V.M., Sidorov D.V., Shavnev A.A., Kurbatkina E.I., Krasnov E.I.
CRACK PROPAGATION IN METAL MATRIX COMPOSITES SYSTEM Ti–SiC UNDER CYCLIC LOADS (review)

The article presents the features of the propagation of cracks in fibrous MCMs system Ti-SiC system under cyclic loads under the review of foreign scientific and technical literature.

The paper presents the mechanisms that provide resistance to crack development and factors affecting its growth process in fibrous MCMs system Ti–SiC. It is shown that the main mechanisms contributing to the resistance to crack development in fibrous MCMs system Ti–SiC under cyclic loads are: shear stresses between the fibers and the matrix alloy, leading to bond breaking at the fiber-matrix interface and the formation of fibers connecting crack faces, preventing crack opening and stress reduction at its apex. The energy dissipation of a moving crack due to such mechanisms is provided only with optimal bond strength at the fiber-matrix interface.

The growth of a fatigue crack has two characteristic successive stages, both during cyclic bending and under cyclic tension. The first is that as the length of the crack increases, its growth rate continuously decreases. Moreover, the crack length corresponding to this stage, as well as the cycle number corresponding to this stage, change. The completion of this stage is characterized by a minimum crack growth rate. The second stage is characterized by a single or recurring event, acceleration of crack growth and its deceleration. It is also noted that, depending on the temperature, medium, and the asymmetry coefficient of the cycle, at a certain intensity coefficient of the applied stress, crack propagation stops. The crack growth rate for the same intensity range of the applied stress decreases with increasing temperature. A decrease in the loading frequency at elevated test temperatures leads to a decrease in the crack growth rate. In vacuum at the same temperatures, the crack propagation velocity is two orders of magnitude&

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7.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-61-67
УДК 678.747.2
Gusev Y.A., Tverdaya O.N.
THE EFFECT OF CALENDARING CLEARANCE ON MAINTAINING THE STRENGTH CHARACTERISTICS OF CARBON FIBER WHEN IMPREGNATING A UNIDIRECTIONAL PREPREG

In the aircraft industry, polymer composite materials (PCM) are widely used for the manufacture of parts and components of aircraft. On the basis of PСM, wing mechanization structures, keel and stabilizer caisson elements, wing and centroplane structural elements, fuselage parts, and engine fan blades are manufactured. Application of modern polymer composite materials ensures reduction of structure weight while maintaining the required elastic-strength characteristics.

One of the main technologies for obtaining these parts is the placement of prepregs on equipment with subsequent autoclave molding. To obtain the required complex of strength properties in PCM structures, when laying out parts and components of aircraft, a combination of prepregs based on glass and carbon fillers is often used. One of the common types of prepregs in the manufacture of PCM elements is molten unidirectional prepregs based on carbon fibers. These prepregs consist of continuous carbon tows laid in one direction and impregnated with a melt binder, on specialized impregnation lines. The main manufacturers of these prepregs in the world are: the American companies Cytec and Hexcel, the Japanese company Toray, the German companies Trans-Textil GmbH and W. L. Gore & Associates, the Swiss company Huntsman Corp. and the American company 3M Co.).

In the Russian Federation, one of the leaders in the production of melt unidirectional prepregs based on carbon tows is FSUE VIAM. The prepregs manufactured by FSUE “VIAM” are used by various aviation enterprises (PJSC Irkut Corporation, UEC-Aviadvigatel JSC, ML Mil Mill MVZ JSC, etc.) for the manufacture of parts and assemblies in helicopter and aircraft construction.

Obtaining melt unidirectional prepregs based on carbon tows on special impregnation lines is not a trivial task and has many featur

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8.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-68-77
УДК 678.8
Satdinov R.A., Veshkin E.A, Postnov V.I., Savin S.P., Kulikov V.V.
DESIGN AND TECHNOLOGICAL IMPROVEMENTS OF CREATION OF SPACE-COMPLEX CONSTRUCTIONS FROM PCM

For the manufacture of spatially complex parts from PCM, the main task is the correct choice of technology for their manufacture. The selected technology should be energy-saving and not laborious. This article discusses the basic technologies for manufacturing complex parts from PCM. The development of technological methods for the manufacture of spatially complex АСS elements was carried out: from studying the properties of the prepreg filler to manufacturing the part; from modeling a master model to manufacturing tooling exactly repeating the theoretical contour of the part; from the choice of technology to its implementation in the manufacture of pipeline elements from PCM for the air conditioning system in aircraft using the thermocompression method.

Investigations of the obtained parts of АСS for leakproofness and compliance with the requirements of Aviation Regulation AP-25 for combustibility were carried out. The selected technological methods allowed the production of parts with specified characteristics that meet the requirements for them.

Based on the totality of the work carried out, the structural and technological methods for manufacturing spatially complex parts from PCM were selected and worked out, based on which:

– developed a new domestic fiberglass brand VPS-42P/T-64, which meets the requirements of Aviation Regulation AP-25 for the manufacture of hard elements of hard currency;

– the created technology for the manufacture of complex-profile designs of hard currency based on domestic fiberglass has allowed the molding of parts of various configurations in one operation;

– the obtained blanks for АСS pipes fully satisfy the tightness requirements and AP-25 (Appendix F Part 1);

&

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9.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-78-86
УДК 621.793
Duyunova V.A., Nikiforov A.A., Terkulova Y.A., Yaroshevskaya V.N., Kozlov I.A.
ELECTROLYTE CORRECTION METHODS FOR Ni–B CHEMICAL COATING SYSTEM

The chemically deposited nickel coating containing boron atoms is not inferior to chromium coatings in terms of wear resistance and protective ability. Nickel-boron alloy coating can be applied to all steel parts. Nickel plating electrolytes have a high dissipative ability compared to chromium plating electrolytes, which contributes to uniform distribution of the coating on parts of complex configuration, including on parts with narrow gaps and blind holes.

Electrolytes for nickel-boron chemical coatings contain nickel salt, a reducing agent based on alkali metal borohydride, solutions for the formation of an alkaline electrolyte medium, a complexing agent to slow down the recovery rate of metallic nickel, buffer and stabilizing additives to improve the characteristics of the solution. In the process of electrolyte correction, it is important to maintain the concentration of not only nickel and reducing agent salts, the concentrations of which decrease during the deposition of the nickel coating, but also the concentration of buffering additives, ensuring the maintenance of the required pH level of the electrolyte.

The correction efficiency increases markedly when borate ions are removed from the electrolyte, which are formed during the recovery of borohydride and contribute to lowering the pH of the solution due to the buffering of the solution.

The addition of alkaline earth metal compounds (Mg2 +, Ca2 +) promotes the formation of insoluble compounds with borates and their removal from the electrolyte by filtration.

In the work, the influence of the number of adjustments on the appearance and microstructure, the microhardness indices of the nickel-boron coating, and the phase composition of the coatings of the samples before and after the correction of the electrolyte were determined.<

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10.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-87-95
УДК 628.517.699.844
Sagomonova V.A., Dolgopolov S.S., Tselikin V.V., Sorokin A.E.
INVESTIGATION OF THE EFFECT OF AN INTEGRATED VIBRATION-ABSORBING LAYER ON THE PROPERTIES OF COMPOSITE THREE-LAYER SOUNDPROOFING SANDWICH PANELS

The article presents the results of the study of the effect of the presence of an integrated vibration absorbing layer on the physical and vibration absorbing properties of experimental samples of composite soundproofing three-layer sandwich panels of various composition and structure, including with an integrated vibration absorbing layer introduced at the forming stage, factors affecting the level of properties of the manufactured experimental samples of the composite soundproofing sandwich panel have been established. Analysis of influence of composition and structure of experimental samples of composite sound-heat-insulating sandwich-panel with integrated vibration absorbing layer on its characteristics was carried out.

The relevance of the work is due to the low initial damping properties of three-layer honeycomb structures used in the aircraft industry for the manufacture of interior panels, floors, helicopter blades, as well as in the production of space technology. Such structures have a structure having high rigidity and low weight, their vibrations fall into resonance with low frequency oscillations generated by air noise, which makes them one of the main ways of transmitting noise and vibration to the cabin of aircraft.

The integration of vibration absorbing layers into the PCM structure at the forming stage results in an increase in the damping properties of the structure. This method is most preferred in comparison with the more conventional method of applying vibration absorbing coatings to the surface of a PCM, which has a number of disadvantages, including a negative effect on the mass characteristics of the composite structure, additional costs and operations for applying vibration absorbing materials. In addition, in most cases, PCM details have a complex surface configuration, which makes it difficult to apply vibration absorption coatings to&

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11.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-96-104
УДК 629.7.023.222
Kuznetsova V.A., Marchenko S.A., Zheleznyak V.G., Emelyanov V.V.
INFLUENCE OF THE SPATIAL STRUCTURE OF REINFORCING FILLERS ON THE PROPERTIES OF THE PAINT COATINGS

In work influence of space structure of reinforcing filler (filamentary crystals of zinc oxide and boron nitride), and also their contents in polymeric matrix on properties of the coverings received on the basis of the epoxy and polyamide film-forming is investigated.
It is studied, what influence is rendered by space structure of filamentary crystals on elasticity of coverings at stretching and their photoabsorption. It is shown that with increase in concentration of reinforcing filler in polymeric matrix from 5 to 25 % (on weight) it is observed monotonous decrease in elasticity of coverings at stretching, however, absolute values of elasticity of the coverings containing filamentary crystals of ZnO at the identical maintenance of the reinforcing filler, exceed the similar coverings containing filamentary crystals of BN on elasticity.
It is established that introduction in epoxy and polyamide matrix of reinforcing filler influences the water resistance of coverings which is characterized by water absorption. Curve dependences of water absorption of coverings on their contents in polymeric matrix have nonlinear character. Presence of reinforcing filler in epoxy and polyamide film-forming to 10 % (on weight) leads to decrease in water absorption of coverings, i.e. promotes structurization, education to denser packing of segments of macromolecules, reducing porosity of coverings and reducing their water absorption.
Influence of space structure of reinforcing filler and its contents in polymeric matrix on erosion resistance of epoxy and polyamide coverings is studied, established that on stability of coverings to erosion essential influence renders both filler particle shape, and its concentration in polymeric matrix. It is shown that the coverings containing filamentary crystals of ZnO at the identical contents possess higher values of erosion resistance, than the similar coverings containing filamentary crystals o

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12.
dx.doi.org/ 10.18577/2307-6046-2020-0-9-105-114
УДК 620.1938:669.715
Varchenko E.A., Kirichok P.F.
RESEARCH OF THE BIOLOGICAL AND CORROSION RESISTANCE OF SAMPLES OF ALUMINUM ALLOY AFTER NATURAL TESTS IN THE GELENJIK BAY. Part 2

The present work is devoted to assessing the productivity of marine biota in the waters of the Gelendzhik Bay and coastal areas of the high seas with a quantitative assessment of the fouling and mechanical properties of samples of AMg6 aluminum alloy after summer exposure with constant full immersion in sea water at 6 monitoring points of the coastal zone of Gelendzhik, including in comparison with the results of studies of the stability of the AMg6 alloy in natural sea water with the exception of the biological factor, it is a continuation of the first part of the stat devoted to the study of biomes and the degree of biofouling of the exposed samples.

The effect of biofouling on the corrosion processes occurring in natural sea water was assessed on the basis of the loss of mass of metal plates (corrosion rate), metallographic analysis, and the loss of mechanical properties of the aluminum alloy during tensile tests compared with similar results after exposure under laboratory conditions. An assessment was also made of the degree and mass of biofouling, and the determination of the type of main fouling.

According to the results of the studies revealed that the maximum values of the corrosion rate were obtained at points related to the "open" sea, slightly decreasing to the geographical center of the bay; the smallest values were obtained at points located on the inner sides of the capes of the bay. The development of corrosion lesions is uniform.

It is established that an increase in the degree of fouling leads to a decrease in the corrosion loss of aluminum alloy samples, a probable cause of which may be the difficulty of oxygen access to the surface of the sample during the formation of a protective "bio-screen". In this case, the minimum degree of fouling of the samples corresponds to the maximum concentration of sea water

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