Articles

 


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1.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-3-14
УДК 669.018.29
Tonysheva О.А., Eliseev E.A.
MODERN STRUCTURAL STEELS OF CRYOGENIC PURPOSE AND INFLUENCE OF SOME ALLOYING ELEMENTS ON THEIR PROPERTIES (review)

The article examines the criteria for the selection of cryogenic materials. It reviews a wide range of cryogenic steels developed in Russia (USSR) and abroad. The review is based on the classification of the steels under consideration by alloying systems. Features of steels of various alloying systems are considered, their mechanical properties are found and compared. Chromium-Nickel steels are the main structural materials for many areas of cryogenic engineering. The greatest advantage of this group of steels is the ability to maintain high toughness after years of operation at low temperatures. Nickel-alloyed chrome-Nickel-manganese steels are recommended for use in oxygen engineering, steels are well welded and have good manufacturability. Austenitic steels, in which Nickel is completely replaced by manganese, are used for operation at low temperatures. Chromium-manganese steels are recommended for use in cryo-genetic machine and instrument making at operating temperatures up to -196 °C. It is noted that the most important property of the structural material for cryogenic equipment is not its strength, but resistance to impact loads, viscosity. Various methods of heat treatment are considered, allowing to obtain the required properties.

The analysis of the influence of alloying elements, which have the most significant impact on the structure and properties of cryogenic steels. With an increase in the Nickel and manganese content in steels, the plasticity determined on smooth and notched samples, as well as the sensitivity to the concentration of stresses, continuously increases. Chrome slightly increases the tensile strength of steel. Increasing the carbon content even in small amounts to 0.05% dramatically reduces the toughness of steel at low temperatures.Tendencies of development of alloying and heat treatment of cryogenic plants are considered.

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2.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-15-23
УДК 621.791.14
Samorukov M.L., Sviridov A.V., Rassokhina L.I., Bityutskaya O.N.
ROTATIONAL FRICTION WELDING OF CASTAND DEFORMED NICKEL SUPERALLOY VG159 SEMIFINISHED PRODUCTS

When developing promising products of domestic engine building, it is important to ensure high technical characteristics of products, the achievement of which is not possible without the use of new structural materials. Often, these materials are characterized by limited weldability by fusion welding methods. Therefore, it is promising to use friction welding to join them. This allows to not only join limited weldable materials, but also significantly reduce the complexity of manufacturing a welded assembly.

The article shows the selection of the optimal technological parameters of rotational friction welding of the heat-resistant nickel alloy VZh159 in heterogeneous and homogeneous combinations.

To select the optimal welding mode, the influence of the thermodeformation cycle and hardening heat treatment was studied, microhardness was determined from the zones of welded joints, the microstructure was studied, the static bending angle, impact strength and short-term strength were determined.

The results of determining the static bending angle made it possible to establish that an increase in pressure values at the stages of heating and forging leads to an increase in strength characteristics.
Analysis of the results of mechanical tests showed that a homogeneous combination of the studied welded joint is characterized by lower values of strength characteristics in comparison with a heterogeneous combination.

The study of the structure of welded joints showed that in the heat-affected zone, a thermodeformational change of the material, characteristic of rotational friction welding, is observed, which is expressed in the “twisting” of the material in the direction of its exit into the graticule.

Based on the results of tests and studies, w

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3.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-24-37
УДК 004.083004.083
Piskorsky V.P., Valeev R.A., Korolev D.V., Stolyankov Yu.V., Morgunov R.B.
TECHNOLOGIES OF MAGNETO-OPTICAL INFORMATION RECORDING IN THIN FILMS OF RARE-EARTH MAGNETICALLY SOFT ALLOYS. PART I. THERMO-OPTICAL INFORMATION RECORDING

The review touches upon modern problems of optical recording of information on magnetic media. The modern devices for recording digital information on magneto-optical disks are described in detail, starting from the choice of material for these disks and ending with the problems of resolution restrictions associated with the fact that the recording area cannot be much smaller than the wavelength of laser light, i.e. 1 micron. The restrictions on minimizing the size of a recorded bit of information are partially overcome by the use of the near field technique, which is described in the review. The need to fulfill several requirements at once for magnetic information storage devices is described as a trilemma in the technology of this process. At the same time, it is necessary to reduce the volume of magnetizable elements (grains) on the magnetic information carrier, which entails a decrease in the potential barrier and stability of the device (data storage time). An attempt to compensate for this drawback by increasing the magnetic anisotropy of the selected material leads to the fact that magnetization reversal requires a large magnetic field, necessary for switching and an increase in energy consumption for its generation. It has been shown that the potential for improving optical recording materials by local optical heating of magnetic films with a laser is far from exhausted, and this technology can be significantly improved within the same physical principles that are used today for local heating of a film and reduction of magnetic anisotropy and the corresponding external magnetic field switching magnetization. Ways to improve the technology of optical recording of magnetic information lie through shortening the duration of laser pulses, which, however, modify the material, create residual changes and structural defects in it, which does not allow counting on a large number of information recording cycles. The first part of the r

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4.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-38-46
УДК 678.072
Khmelnitskiy V.V., Sarychev I.A. S, Khaskov M.A., Guseva M.A.
RESEARCH OF THE EFFECT OF EPOXY RESINS ON THE PROPERTIES OF BENZOXAZINE MONOMER BA-a AND THEIRS COPOLYMERS

One of the important properties of benzoxazines as a class of polymers is their high chemical compatibility with various resins. In the present work compositions based on benzoxazine monomer and epoxy resins of various structures were obtained. Their rheological characteristics in special dynamic viscosity at different temperatures and profiles in dynamic mode were determinated. Water absorption and glass transition temperature of polymer matrix samples were investigated. Conclusions about modification of benzoxazine monomers with epoxy resins have been made.

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5.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-47-57
УДК 678.8
Naydenov D.D., Khaskov M.A., Petrova A.P.
CONSTRUCTION OF THE DIAGRAM OF ISOTHERMAL TRANSFORMATIONS OF THERMOSETTING POLYMERS ON THE EXAMPLE OF THE ADHESIVE MATRIX

The study of thermosetting matrices in order to develop a technology for the production of polymer composite materials (PCM) taking into account the final structures is an important and urgent task.

Most thermosetting binders, due to specific properties such as reduced heat transfer characteristics (heat capacity, heat conductivity), as well as high heat dissipation, require careful study of both the heat transfer processes and the kinetics of curing. The curing kinetics is a key characteristic of the thermosetting binder, which determines the conditions of their processing and their storage.

One of the quite convenient ways to visually represent the kinetics of curing is the construction of isothermal transformation diagrams (Time–Temperature–Transformation diagram or TTT-diagram), which can be determined as the beginning of the most important structural transformations (gelation, vitrification), requiring consideration during processing, and the conditions of isothermal storage.

These diagrams indicate the beginning of a certain event in the holding process at a certain temperature, which can be chosen as the degree of pre-rotation at which the thermosetting matrix is delaminated.

In this regard, the construction of Time–Temperature–Transformation diagram with isoconversion curves of potential delamination applied to it is an important and urgent task, in particular for predicting the storage time of filled adhesives under various isothermal conditions.

The paper deals with the construction of a TTT-diagram using kinematic calculations and refinement of the data obtained by various methods of thermal analysis, such as differential scanning calorimetry (DSC) and thermal mechanical analysis (TMA).

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6.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-58-67
УДК 669.018.95
Kosolapov D.V., Shavnev A.A., Kurbatkina E.I., Nyafkin A.N., Gololobov A.V.
STUDY ON STRUCTURE AND PROPERTIES OF DISPERSION HARDENED MMC BASED ON ALUMINIUM ALLOY OF Al–Mg–Si SYSTEM

In the present study, metal matrix composite (MMC) material based on the aluminum alloy AD31 containing 20 vol. % silicon carbide was obtained by powder technology using mechanical alloying followed by hot pressing. Studies of the formation of the composite granules structure during the mechanical alloying process have been carried out. Samples of a monolithic composite material were produced for measuring density and carrying out strength tests. Tests of produced samples were carried out and the values of the MMC density and strength characteristics at room temperature were determined.

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7.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-68-77
УДК 678.747.2
Kablov E.N., Valueva M.I., Zelenina I.V., Khmelnitskiy V.V., Aleksashin V.M.
CARBON PLASTICS BASED ON BENZOXAZINE OLIGOMERS – PERSPECTIVE MATERIALS

The results of a study of the possibility of creating binders and CFRPs based on benzoxazine oligomers are presented. Benzoxazines based on 4,4'-dihydroxy-2,2-diphenylpropane with a different ratio of mono- and diamine in the system were synthesized as binders in the manufacture of CFRPs. Equal-strength carbon fabric of VTkU-2.200 grade manufactured by FSUE «VIAM» was used as a reinforcing filler in the manufacture of experimental prepregs (solution technology) and CFRPs based on them (pressing method).

The viscosity of oligomeric benzoxazines, the curing process of the binder in the prepreg, the physical and mechanical properties of carbon plastics: binder content, glass transition temperature, density, water absorption, strength and modulus of elasticity under static bending, compressive strength were studied, the influence of heat and moisture effects on the properties of carbon plastics was studied.

It is shown that with the introduction and subsequent increase in the diamine content from 30 to 70%, the glass transition temperature of carbon fiber rises by 46% – from 151 to 220°C, which increases the heat resistance of the material. Preservation of strength at elevated test temperatures for carbon plastics with a diamine content of 30-70% in the composition is 80-94%, without diamine – 66%.

The studied CFRPs have low water absorption (not more than 1,07% for 3 months) and moisture saturation (0,63–0,66% after 2 months of exposure in a climatic chamber), the preservation of properties after moisture saturation is 77–93% at room temperature and 66–88% – at elevated test temperatures.

After 4 months of storage, prepregs based on compositions with a diamine content of 30 and 50% retain the ability to process, and carbon fiber based on the

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8.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-78-91
УДК 621.822.1
Burkovskaya N.P., Sevostyanov N.V., Bolsunovskaya T.A., Efimochkin I.Yu.
IMPROVEMENT OF MATERIALS FOR SLIDING BEARINGS OF INTERNAL COMBUSTION ENGINES (review)

The process of improving the materials of sliding bearings (PS) of internal combustion engines (ICE) of automobiles depending on the requirements: from cast "babbit", multilayer, composite bearings to promising ceramic, is considered. PS in the internal combustion engine is one of the most important parts of the engine, the requirements for the functional properties of which continue to grow, as well as for the material itself. The durability of a sliding bearing is achieved when its materials combine strength (load capacity, wear resistance, cavitation resistance) with softness (mating, running-in ability, ability to absorb abrasive particles, damping vibrations).

Since transport is the main source of greenhouse gas emissions, for cars today the level of CO2 emissions is strictly standardized. The requirements for materials of sliding bearings that determine the development of materials science in the field of ICE anti-friction materials are presented.

The main world and domestic manufacturers of bearings of internal combustion engines are presented. Various types of bearing structures and manufacturing techniques for their manufacture are shown. It has been established that technologies involving the use of multilayer composite materials (MKM) or bearings with a layered structure, the performance of which is determined by the integrity of their antifriction layer, are widely used.

Despite the fragility and high cost of manufacture, today the most promising bearings in the field of bearing production are ceramic bearings, which are not prone to setting during grinding due to their strictly oriented covalent bonds and relatively low concentration and mobility of defects in the crystal lattice.

It should be noted that the specific choice of the composition of the material is dete

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9.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-92-100
УДК 621.762
Trofimenko N.N., Efimochkin I.Yu., Dvoretskov R.M., Batienkov R.V.
OBTAINING FINE-GRAINED CEMENTED CARBIDE ALLOYS OF THE WC–Co SYSTEM (review)

The work represent the relevance of research of cemented carbides alloys. The classification of hard alloys is given depending on the composition and purpose. The characteristic microstructure is described and the classification of cemented carbides alloys is indicated depending on the size of the carbide phase. The data on the effect of the carbide phase size on the indicators of physicomechanical properties (flexural strength, hardness, thermal conductivity) of WC–Co system alloys are presented. Various technological options for obtaining the starting powders are considered. The technology of manufacturing a powder mixture is presented and criteria for evaluating the quality of mixing are indicated. Various options and features of the process of molding a powder mixture are described. The equipment used in industrial production is indicated. The influence of technological factors (reduction temperature) for the production of tungsten and tungsten carbide powders on the grain size of the carbide phase is considered. The stages of the liquid phase sintering process in the WC–Co system are described. Particular attention is paid to the process of recrystallization through the liquid phase, which determines the growth of grains of the carbide phase. In order to obtain WC particles of uniform size in grains and relatively fine-grained alloys, it is necessary to provide a uniform particle size distribution of the initial carbide powder, which will be more uniform under certain production conditions (relatively high temperatures) ensuring the formation of crystals as close to equilibrium as possible; the latter leads to a weakening tendency of the formation of individual large crystals.

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10.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-101-117
УДК 539.3-620.1
Oreshko E.I., Utkin D.A., Erasov V.S., Lyakhov A.A.
METHODS OF MEASUREMENT OF HARDNESS OF MATERIALS (review)

In article the review of the main methods of measurements of hardness in a chronological order which showed is presented that the indentation is one of the main ways of mechanical tests which differs simplicity of use and great opportunities for determination of tension in blankets, viscosity of destruction, thermal stability of materials, carrying out researches of structural components of a material, adhesive and elastic properties, resistance to plastic deformations, resistance to destruction, specific work of deformation, the analysis of a gradient of hardness on thickness of a blanket, an assessment of anisotropy of strength properties of a monocrystal, shortness  became, microheterogeneity of plastic deformation on local volumes of a material, the physical and chemical analysis when studying charts of a condition etc.

The following methods of measurement of hardness are considered: static hardness, dynamic hardness, kinetic hardness, microhardness, nanoindentation. Possibility of application of a method of finite element for creation of a curve of stretching of materials by results of hardness measurement is considered. The comparative analysis of methods of an indentation is carried out and the major factors influencing result of measurement of hardness are considered. The analysis of compliance of domestic and foreign standards on methods of measurement of hardness is carried out.

At hardness measurement by a method of an indentation it is necessary to consider a set of the factors influencing results of experiment, basic of which are: loading size; print arrangement; vibrations; a peening of a surface of a sample when polishing and other mechanical influences; error of measurement of the sizes of a print, etc.

The most perspective is the kinetic method of measurement of hardness which allows to carry out a numbe

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11.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-118-125
УДК 669.018.44:669.245
Yakimovitch P.V., Alekseev A.V.
DETERMINATION OF SULFUR IN CASTING HEAT-RESISTANT NICKEL ALLOYS BY GD-MS

At present, in the modern aviation industry and engine building, heat-resistant nickel alloys are widely used, which experience enormous thermal and power loads during operation. Operational characteristics and reliability are the main indicators of the quality of materials made from these alloys. For the design and manufacture of modern aircraft, it is necessary to create new types of heat-resistant alloys with increasingly better properties.

An extremely important component in the success of the production of high-quality nickel alloys is the tight control of their chemical composition, especially the sulfur content, which even in trace amounts negatively affects the various properties of metals and alloys.

Inductively coupled plasma mass spectrometry (ICP-MS) is the most preferred multi-element analysis method. The positive characteristics of this method are - high sensitivity, the ability to simultaneously determine a large number of elements, the accuracy of the analysis When using this method, it is necessary to take into account the presence of multiple spectral interference affecting the results of the analysis. To overcome spectral interference, you can use the equations of mathematical correction, as well as special reaction-collision cells, which are an integral part of modern ICP-MS spectrometers.

It is possible to completely overcome mass spectral interference in the determination of sulfur by using high-resolution mass spectrometry with a magnetic sector and electrostatic mass analyzer. This method allows you to completely separate the signal from the sulfur isotope 32S + signal interfering signals. So when using the method of high-resolution mass spectrometry for multi-element analysis of stainless steel, while the minimum sulfur content found was 0.038% of the mass.

Thus, t

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12.
dx.doi.org/ 10.18577/2307-6046-2020-0-1-126-134
УДК 621.74.045
Guseva M.A., Aslanyan I.R., Ponomarenko S.A.
STUDY OF THE RHEOLOGY OF MODEL COMPOSITIONS DEPENDING ON THE NATURE AND RATIO OF THE MAIN COMPONENTS

Lost wax casting is currently the most common method for producing cast parts of complex configuration. The quality and geometric accuracy of castings depends on the technological characteristics of the wax, which are determined by the properties and the ratio of the components included in their composition. On the basis of high-tech molding and core model compounds, which enable accurate reproduction of dimensional parts with complex geometry, modern cast parts and gas-turbine engine blades are made from the latest heat-resistant alloys.

The rheological behavior of wax is the theoretical basis for the processes of their processing in the manufacture of investment models and highly refractory ceramic molds, as well as the determining method for studying their technological properties. During application, the melt of the model polymer composition undergoes a certain deformation, which is accompanied by structural transformations and a change in rheological properties. The rheology of the model melt allows, in particular, to evaluate the speed and completeness of filling and removing the composition to / from the mold cavities, which positively affects the imperfection of the models. A modern wax consists of 5-6 or more components, each of which plays a functional role in the entire composition: hardening components (polymer synthetic resins), a mutual solvent (for example, paraffin), a plasticizer (for example, savilen), in addition, dyes and other fillers. The deformation of the polymer composition during the formation of the product can greatly depend on the nature and ratio of its constituent components, a similar negative effect is often encountered in practice when the manufactured products have a tightening and other appearance defects, for example, cracking.

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