Articles

 


№1 | №2 | №3 | №4-5 | №6-7 | №8 | №9 | №10





1.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-3-10
УДК 669.017.165
Bazyleva O.A., Karashaev M.M., Shestakov A.V., Arginbaeva E.G.
EFFECT OF ANNEALING TEMPERATURE ON THE HOMOGENEITY OF INTERMETALLIC ALLOY BASED ON Ni3Al COMPOUND

The paper presents the results of studies aimed at studying the structural and phase state of the VIN4M alloy. The studies were carried out on samples obtained by directional crystallization using the UVNS-5 unit with computer-controlled process control. To obtain single-crystal castings, the metal temperature was Т=[ТL+(180÷200)]°С, mold temperature Т=[ТL+(200÷220)]°C, crystallization rate Vcr=[4÷8] mm/min. It has been shown that when producing single-crystal castings by the method of high-gradient directional crystallization according to the presented regimes in the direction of growth of the single crystal, the maximum deviation from the given crystallographic orientation does not exceed 5°. Samples for determining the critical points of the material by the differential thermal analysis (DTA) method were also made in order to select the regimes of hardening heat treatment of the alloy, consisting in the possibility of reducing dendritic segregation by dissolving the γ'-phase of eutectic origin in the interdendritic regions and its further isolation in in the form of fine particles along the axes of dendrites, as well as hardening of a γ-solid solution of intermetallic alloy.

It was found that the maximum effect of homogenizing annealing is achieved at a temperature of 1320°C, exposure at which contributes to the maximum dissolution of the γ'-phase of eutectic origin located in the interdendritic regions and its subsequent isolation along the dendrite axes in a finely divided form.

As a result of studying samples of single crystals from an alloy of the Ni–Co–Al–Cr–Mo–W–Ti–Re–Ta system treated in the selected mode, it was found that the tensile strength at room temperature σv20 was 1150 MPa, and the yield strength σ0,2 20-60

Read in Russian

2.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-11-19
УДК 669.295
Kablov E.N., Nochovnaya N.A., Shiryaev A.A., Davydova E.A.
INVESTIGATION OF STRUCTURAL AND PHASE TRANSFORMATIONS IN METASTABLE β-TITANIUM ALLOYS AND EFFECT OF COOLING RATE FROM HOMOGENIZATION TEMPERATURE ON STRUCTURE AND PROPERTIES OF VT47 ALLOY. Part 2

The analysis of structural and phase transformations occurring in metastable β-titanium alloys with a degree of doping with β-stabilizing elements in the range from 14.0 to 26.5 % by molybdenum equivalent is carried out.

The experimental results and the analysis of scientific and technical literature sources have shown that a large number of factors influence the processes which take place during cooling, as well as the structure and properties after isothermal exposures, including structural and phase transformations (the peculiarities of the secondary α and intermediate ω and β′ phases formation) and the completeness of recrystallization processes. The differences in decomposition processes of the metastable β phase and the features of the secondary α phase particles precipitation in recrystallized and polygonized structures are considered. The effect of defects in the crystal structure and subgrain boundaries on the processes of new particles nucleation of the secondary α phase is shown.

The problems and relationships of the structural defects formation tendency (in the form of precipitation-free zones) with the features of the metastable β phase decomposition mechanism and the completeness of recrystallization processes have been considered.

The effect of various cooling rates on the structure and properties of the metastable β-titanium VT47 alloy have been studied after isothermal exposures. It has been shown that a large volume of the α phase precipitates is formed after a full cycle of heat treatment, the precipitates locating both inside the grains and along the grain boundaries.

It has been revealed that cooling in the selected rates (from “in water” to ʋ740-400=3.8 °C/min) does not significantl

Read in Russian

3.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-20-34
УДК 620.178.6:669.715
Shchetinina N.D., Rudchenko A.S., Selivanov A.A.
THE APPROACHES THAT ARE USED FOR DEVELOPED OF OPTIMAL STRAIN MODES OF ALUMINUM-LITHIUM ALLOYS (review)

This article provides a review The article discusses the approaches that are used by researchers in the development of optimal deformation modes of aluminum-lithium alloys.of publications in the field of the research of aluminum-lithium alloys deformation processes, which are used in the construction of aircraft and space technology products. The review summarizes the research that are devoted to the influence of parameters of pressure treatment on structure formation processes in aluminum-lithium alloys and the mathematical modeling as applied to hot deformation processes.

It is shown that the final structure and mechanical properties of the alloy depend on the parameters of heat treatment and pressure treatment. The understanding of processes occurring in the alloy during hot deformation is based on research of the evolution of the microstructure during deformation under various temperature and speed conditions. To produce semi-finished products from aluminum-lithium alloys with isotropic mechanical properties and high elongation, it is necessary to conduct deformation taking into account the optimal parameters of the deformation process. The optimal temperature and speed conditions for the deformation of a particular alloy are determined by applying mathematical modeling methods for the behavior of the alloy during hot deformation. The article discusses the approaches that are used by researchers for developed of optimal strain modes of aluminum-lithium alloys. The expediency of applying equations based on the Zener-Hollomon parameter to describe the rheological properties of the alloys under study is shown. The dynamic material model and it's application to control the microstructure and properties of hot worked alloys using a processing map that create using parameter of efficiency of power dissipation  and instability parameter  is discussed.

Read in Russian

4.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-35-45
УДК 621.792
Gerasimov D.M., Ilyukhina M.A., Glazov P.A.
LOW-MOLECULAR ORGANOSILICONE RUBBERS IN SEALANT COMPOSITIONS (review)

The greatest application for sealing found curing at the room temperature materials on the basis of low-molecular rubbers since they more answer demanded operational properties: physicomechanical, adhesive, corrosion, to the temperature range of working capacity.

In Russia the main achievements in the field of organosilixane sealants fall on VIAM Federal State Unitary Enterprise, developing and letting-out more than 30 names of various hermetics. Along with VIAM Federal State Unitary Enterprise development of synthesis and production of low-molecular siloxane liquids, rubbers, pitches, etc. components for manufacturing of siloxane elastomer since 1960 is JSC GNIIKHTEOS, NIISK Federal State Unitary Enterprise of S. V. Lebedev. In development of organosilixane sealants more than 20 known firms, including DOW CORNING, GENERAL ELECTRIC, WACKER abroad are engaged, etc.

The way of curing of low-molecular siloxane rubbers was developed for receiving elastomer in VIAM without heating, by their catalytic polycondensation with multifunctional silons in the presence of catalysts on the basis of tin and titan salts without use of high temperatures (a way of «cold curing» силоксанов).

To sealants of aviation appointment, besides the general requirements with which have to satisfy sealants, make additional demands for firmness of a material to simultaneous influence of oil fuels and high (to 250 °C) temperatures.

From elastic polymers existing now only ftorelastomer – fluorosiloxane and ftororganosiloxane rubbers can form a basis for creation of the materials meeting so rigid requirements. VIAM Federal State Unitary Enterprise and is now the main producer of fluorosiloxane sealants in Russia. The market of sealants in Russia, despite the crisis phenomena, is in a stage of acti

Read in Russian

5.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-46-53
УДК 678.747.2
Timoshkov P.N., Khrulkov A.V., Grigoreva L.N.
СARBON FIBER TRANSMISSION SHAFT. MATERIALS AND TECHNOLOGY (review)

In recent years, the function of polymer materials in any industry has changed somewhat. Composite materials began to be trusted with increasingly important tasks. A list of parts, such as a car, which today is made from polymers, would take more than one page. Body and cab, tools and electrical insulation, trim and bumpers, radiators and armrests, hoses, transmission shafts, seats, doors, hood. Moreover, several different companies abroad have already announced the start of production of all-plastic cars.

If we talk about composite materials for the automotive industry, it will primarily be carbon fiber products. Carbon fibers are made from synthetic and natural fibers based on polymers. Depending on the processing mode and feedstock, materials of different structures and with different properties are obtained. This is the main advantage of composite materials. They can created with the initially set properties for a specific task. Carbon fiber has been in the automotive industry for many years, and its use is growing every year. The most important advantage of carbon fiber is the production of products with low weight and high strength. The use of composites in the automotive industry can reduce the weight of the vehicle by 20-25%. Due to this, the efficiency of the engine significantly increases.

Car transmission shafts made of carbon fiber also found their place. The advantage of a carbon-plastic shaft over a metal is a lower moment of inertia when the transmission is hit at the moment of alternating load and a decrease in the load on other components of the transmission, as well as an increase in traction. This characteristic is very important in the construction of sports cars, but the use of a carbon transmission shaft in public vehicles also has several advantages.

Read in Russian

6.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-54-63
УДК 66.067.124
Babashov V.G., Varrik N.M., Karaseva T.A.
POROUS CERAMIC FOR FILTRATION OF METAL MELTS AND HOT GASES (rеview)

An overview is given of the highly porous ceramic materials currently used for filtration of metal melts and hot gases, as well as methods for their production. Gas permeability and high specific surface area in combination with refractory properties allow the use of highly porous oxides in processes carried out at high temperatures in chemical media when other materials are not applicable. The article contains information on the types of highly porous ceramics currently used for filtration, filter manufacturers and methods for their production.

Heat-resistant high-porosity ceramics are currently very popular in various industries, in particular, for filtration of solutions, casting metal alloys, hot gases. Various types of porous ceramics for filters are available on the market, both from aluminium and zirconium oxides or combinations of aluminium oxide with silicon and magnesium oxides, and from silicon or titanium carbides. Methods for producing highly porous ceramic filters are based mainly on the principle of using ceramic slips in combination with organic materials used to form pores. Ceramic materials used to create a highly porous filter, organic pore-forming materials and pore-making techniques may be different.

Modern high-porosity ceramic materials have a number of advantages for use as high-temperature filters, such as resistance to reducing medium at melt temperature, resistance to thermal shock, high filtration efficiency due to the presence of a branched network of open pores. But there are also shortcomings: insufficient strength, high cost, low environmental friendliness of production. The efforts of the developers to eliminate these shortcomings are aimed at creating new compositions of ceramic materials and obtaining various combinations of porosity, improving existing technologies for producing porous ceramics. The use of various pore-forming

Read in Russian

7.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-64-76
УДК 539.24
Startsev V.O., Valevin E.O., Gulyaev A.I.
THE INFLUENCE OF POLYMER COMPOSITE MATERIALS’ SURFACE WEATHERING ON ITS MECHANICAL PROPERTIES

The difference in weathering of VKU-24, VKU-7T, VKU-25 and KMU-4E-2M carbon-reinforced plastics on the exposed (front) and shaded (back) side of the samples was studied during the natural exposure in a moderately warm climate for 75 months. Mean and standard deviation of peak and valley height difference was measured on both sides of the samples using profilometry. Flexural strength was also measured on both sides (samples were placed on different sides during mechanical testing) to evaluate differences in weathering. Samples were dried for 14 days at 60 °C, which was enough to achieve mass stabilization and therefore, removes moisture plasticization. Peak and valley height difference was higher on the Sun exposed side for all materials studied. This effect was the largest for KMU-4E-2M carbon-reinforced plastic. The flexural strength was reduced by 20–39% after 75 months of exposure. For all materials except KMU-4E-2M the difference between flexural strength, measured by applying constant load on the exposed and shaded side, was negligible, while for KMU-4E-2M there was a 10% difference. For all materials except KMU-4E-2M peak and valley height difference distribution peaks were 25–33% higher on the exposed side compared to the shaded side, while for KMU-4E-2M the difference was 84%. It was shown that if the difference between exposed and backed peak and valley height difference distribution peaks is below 35%, there is no difference in flexural strength measured by application of the force from exposed and backed side. The difference in flexural strength is significant for carbon-reinforced plastics with large (up to 84%) difference between exposed and backed side surface’s profile parameters.

Read in Russian

8.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-77-93
УДК 621.793
Kozlov I.A., Leshchev K.A., Nikiforov A.A., Dyomin S.A.
COLD SPRAY COATINGS (review)

Process of cold spray represents drawing flexible metal particles on metal parts, ceramic or concrete products at the moment of collision of powder mix with surface substrate. The dusting of coatings occurs thanks to plastic strain of metal particles. Preliminary particles acceleration to supersonic speed occurs in nozzle, thus temperature of evaporated material does not exceed temperature of their melting. The metal layer put on product by cold spray, differs the increased adhesion with surface of basis and is steady against mechanical damages.

The different constructive decisions directed on simplification of installation for dusting and decrease in its weight, and also increase of overall performance of devices of figurative type are applied to expansion of technological capabilities of cold spray of powder materials.

Today, for increase of efficiency of work and quality of drawing coverings on details on productions the automated systems for dusting of CS of coverings are implemented.

Complexes, as a rule, consist of installation for the dusting scanning (robotized) device, the filtro-exhaust device, the dust-protection camera and rack.

Today the technology of development of new powder materials and technology of their dusting actively develops. Feature of technology is possibility of drawing metal powder on incompatible for welding and the soldering of metals. Also this technology is used for giving of functional properties to material, for example wear resistance increase, corrosion protection, creation of heat-protective coverings.

In mechanical engineering cold spray will be applied for the purpose of protection or giving of functional properties of surface of detail more often, allows to eliminate defects (cavities, chips), and also it is appli

Read in Russian

9.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-94-100
УДК 629.7.023.222:535.23
Devin K.L., Agafonova A.S., Sokolov I.I.
PROSPECTS FOR THE USE OF RADIO-ABSORBING MATERIALS TO ENSURE ELECTROMAGNETIC COMPATIBILITY OF AVIONICS

The article describes the characteristics of RPM of a dielectric type (material of the VRM-1 brand) using a filler in the form of carbon fiber, developed at FSUE “VIAM”. The material is a sheet calibrated by radio characteristics based on a polyurethane composition. In this material, the polymer matrix captures the uniform distribution of the electrically conductive filler in the volume of the material and its length is selected in such a way as to ensure the level of electromagnetic radiation (EMR) absorption to a level of minus 10 dB in the operating frequency range from 8.0 to 13.0 GHz, with a material thickness of 3.8 mm. A distinctive feature of the material is its homogeneity, that is, the electrophysical characteristics do not undergo significant changes in the direction from the surface deep into the material.

In aircrafts, polymer composites are widely used, which are characterized by high specific strength, the ability to control the structure and obtain products of complex shape. This paper presents RAMs for structural purposes for providing EMC on-board equipment of the VRM-12 brand. The material is a monolithic fiberglass filled with discrete carbon fiber. A distinctive feature of the material is that it is a gradient structure made of filled fiberglass, which allows us to recommend it for providing EMC on-board electronic equipment and protection against unauthorized exposure to EMR in a wide frequency range from 2.5 to 15 GHz.

At present, radio absorbing coating (RAC) based on the commercially available carbonyl iron, which have magnetic losses and effectively absorb EMR in the microwave range, which can also be proposed for use in unmanned aerial vehicles, are widely used.

Material type VRP-18 is a typical representative of RAC with magnetodielectric losses. The coating is formed from a cold cured&

Read in Russian

10.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-101-108
УДК 543.51:669.245
Alekseev A.V., Yakimovitch P.V.
APPLICATION OF THE GLOW DISCHARGE HIGH RESOLUTION MASS SPECTROMETRY METHOD IN ANALYSIS OF NICKEL ALLOYS

Currently, nickel alloys are widely used in various industries (aircraft, engine). These materials are characterized by increased heat resistance, heat resistance, and also high mechanical strength, which makes it possible to use products made from these alloys at high temperatures reaching 1640-1940 K.

One of the most important aspects of the production of high-quality nickel alloys is the control of the chemical composition of the produced materials, both basic and impurity elements.

The most commonly used multielement analysis methods include inductively coupled plasma atomic emission spectrometry (ICP-AES). This method is suitable for determining both the main components of the alloy and part of the impurities. The disadvantages of the method include the inability to determine most of the harmful impurities, as well as the presence of a large number of spectral interference (overlays), which reduces the accuracy of the analysis results.

The method of high resolution glow-discharge mass spectrometry (MSTR) allows the determination of both basic and impurity components of nickel alloys. The method does not require long sample preparation with dissolution, allowing analysis directly from a solid sample, and also due to the high resolution, spectral interference is overcome. However, the list of normative documents for this analysis method is extremely small, and for the analysis of nickel is completely absent.

In the course of the work, an analysis was made of certified standard samples (СО) of the composition of the alloy type VZHM-5: VZHMP-1 and VZHMP-3, as well as the standard sample IN718. To build the calibration dependences, we used certified standard enterprise samples (SOP) of the composition of the alloy type VZHM200 manufactured at FSUE VIAM: 109k, 111k, 112k, 113k and 114k. The

Read in Russian

11.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-109-122
УДК 52-17:539.42
Grinevich D.V., Bouznik V.M., Nuzhny G.A.
REVIEW OF NUMERICAL METHODS FOR SIMULATION OF THE ICE DEFORMATION AND FRACTURE

The article provides an overview of modern works of the use of various numerical methods for modeling the deformation and brittle fracture of ice.Application’s examples are considered: finite element method, hydrodynamics of smoothed particles, discrete element method. The application of numerical methods for quasistatic loading is considered: compression, three-point and four-point bending; dynamic loading: shock, explosive, falling from a height.The finite element method is considered in the following formulations: models of elastic-plastic material with kinematic and isotropic hardening, fracture criteria, cohesion zone method, model of the destructible foam, Lemaitre material model with damage, material model of Govindjee-Kay-Simo with brittle fracture, Johnson-Holmquist material model.The Lemaitre model with damage in many studies showed an adequate and satisfactory result in various settings.The works considered modeling of sea ice and freshwater ice. However, the formulations of the problems to be solved are still limited; they do not analyze ice anisotropy, variability, salinity, and temperature conditions.The smoothed particles hydrodynamic allows modeling of the complex process of destruction of ice bodies.

The use of SPH is limited to two-dimensional formulation. The discrete element method seems promising for use in modeling the deformation and destruction of ice. The problems are solved both in two-dimensional and in three-dimensional formulation. It is possible to build multiphysical models of complex water–ice–construction systems (combination of computational fluid dynamics, DEM and FEM). The method has the possibility of using inhomogeneous and non-spherical particles. Also in the future, particle bond models can be improved to more accurately model complex fracture processes.

Read in Russian

12.
dx.doi.org/ 10.18577/2307-6046-2020-0-8-123-130
УДК 677.017
Barinov D.Y., Okulov V.N.
STUDY OF THE INSULATING ABILITY OF WORKING CLOTHES FOR EMPLOYEES OF AVIATION ENTERPRISES

At present, new materials for structural and functional purposes are being created to ensure the production of modern samples of civil and military aviation equipment. Despite the increasing role of automation, the characteristics of new materials are still influenced by the culture of production and the human factor. The emergence of conditions in which the work of engineers and technologists in the aviation industry becomes uncomfortable, leads to a decrease in the quality of products.

Comfortable conditions for human work, especially in winter, are provided by the use of high-quality clothing and shoes. So, one of the main elements of shoes are insoles, which not only perform a heat-insulating function of protecting the foot from cold street temperatures, but also provide an even distribution of pressure over the area of the foot and comfort when walking. There are a large number of different materials for making shoe insoles, so an important task is to compare their thermal characteristics, in particular, thermal conductivity and thermal insulation ability.

In this paper, a laboratory study of the thermal conductivity of three types of multi-layer insoles for shoes: all-season and winter based on compacted felt and porous wool. The dependences of changes in the thermal conductivity of insoles at different operating temperatures are determined. The results obtained were used for mathematical modeling of heat transfer in an object consisting of a shoe sole, an insole, and a human foot. For this purpose, physical and mathematical models were developed that take into account all the main processes. The software package COMSOL Multiphysics was used for modeling. Based on the results, dependences of foot temperature changes at outdoor temperatures of +10, 0 and -10 °C are constructed. The time of a person's comfortable stay on the street is shown, with th

Read in Russian