Articles

 


№1 | №2 | №3 | №4 | №5 | №6 | №7 | №8 | №9 | №10 | №11 | №12





1.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-3-10
УДК 669.018.44:669.245
Lomberg B.S., Shestakova A.A., Letnikov M.N., Bakradze M.M.
THE INFLUENCE OF TEMPERATURE AND STRESSES ON NATURE OF NANOSIZE γʹ-PHASE IN Ni-BASE SUPERALLOY VZh175-ID

The presented article is the continuation of the range of works on the investigation of Ni-base superalloy VZh175-ID which are designed for jet-engine disk billets obtained via cast-and-method. The investigation of the possible changes of nano-particles of γ'-phase with size below 100 nm at the application of various strains and temperatures enters into the objectives of the work.

The specimens after tensile testing at room temperature, after rupture strength testing at certification regimes at 650 and 750°C and also after rupture strength testing at regimes, which are distinctive for exploitation conditions of the disks of high pressure turbine (HPT) of civil aircraft jet-engine were chosen as the objects of the investigation.

The investigation of nano-sized particles of the reinforced γ'-phase was carried out via scanning electron microscopy method at the magnifications up to 50000. The areas of the specimens near the fracture zone as well as at the distance from it were analyzed.

As a result of the investigation it was shown that the application of gap tension stress at room temperature practically does not introduce any changes in the phase composition of VZh175-ID alloy. The analogous result was carried on the specimens after rupture stress testing at 650°C. The nano-phase particles are presented in the alloy microstructure at these conditions. The microstructure degradation was found in the investigated specimens after rupture strength testing at 750°C. The specific hollows form near the fracture zone and the destruction of the specimen takes place on it. It should be notes that the stress was chosen for 100-hour time base but actually time to failure of the specimen has been 244 hour. The microstructure investigations of the specimens after the imitation of the exploitation have shown the stabil

Read in Russian

2.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-11-19
УДК 669.245
Kuzmina N.A., Pyankova L.A.
CONTROL OF CRYSTALLOGRAPHIC ORIENTATION OF MONOCRYSTALLINE NICKEL CASTINGS HEAT-RESISTANT ALLOYS BY X-RAY DIFFRACTOMETRY

The article analyzes the methods of х-ray diffraction used to assess the quality of the structure of single-crystal castings of heat-resistant nickel alloys. The results of determining the deviation from the crystallographic orientation of single crystals of nickel heat-resistant alloys obtained on an х-ray diffractometer equipped with a curved position-sensitive detector are presented. The data of optimal shooting conditions for obtaining a swing curve in order to control the crystallographic orientation of single-crystal castings of heat-resistant nickel alloys are presented.

It is revealed that the most optimal conditions are shooting samples with a scanning step of 0,5 degrees and exposure at a point of 20 seconds, corresponding to the full rotation in the plane perpendicular to the normal surface. Since the diffractometer used in this study is a desktop device with a low-power х-ray source, this imposes certain restrictions on obtaining swing curves completely identical to those obtained on high-resolution diffractometers with a point scintillation detector. So the minimum shooting time on the diffractometer Difrey-401, sufficient to obtain a quality swing curve is 4-6 minutes, which is 1,5–2 times more than on high-power diffractometers.

The measurement results obtained on a diffractometer with a curved position-sensitive detector are comparable to those obtained on a diffractometer with a point scintillation detector. Based on the study, we can talk about the possibility of using a diffractometer with a curved position-sensitive detector to control the quality of the structure of single crystals of nickel heat-resistant alloys.

The accuracy of measurements in determining the deviation from the crystallographic orientation on any of the diffractometers is limited by the accuracy of the casting cut, usually not exc

Read in Russian

3.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-20-28
УДК 669.018.44
Rassokhina L.I., Bityutskaya O.N., Gamazina M.V., Echin A.B.
TECHNOLOGICAL PROCESS DEVELOPMENT OF CASTING DETAILS «DIFFUSER» FOR GAS TURBINE ENGINES FROM VZh159 SUPERALLOY IN THE CONDITIONS OF THE MACHINE-BUILDING ENTERPRISE

In FSUE «VIAM» was developed high-tech structurally stable deformable alloy VZh159 with an operating temperature of up to 1000°C, superior to the properties of the alloy EP648. VZh159 has high characteristics of weldability in the deformed state, which ensures maintainability of parts and welded assemblies from it. The use of the alloy in the aviation industry has long been limited due to the lack of casting options required to obtain complex parts from castings due to the impossibility of their manufacture from a deformed workpiece or sheet.

According to the technological recommendations of FSUE «VIAM» in the conditions of machine-building enterprise JSC «MMP. V.V. Chernysheva» the development of technology of manufacture of castings parts made from superalloy VZh159 «diffuser»: the developed optimal design of Gating-feeding system, which made the model blocks and ceramic molds, worked out the technological parameters of the casting parts at the installation of WIPE-3 has been control the quality of the castings, visual and radiographic method was developed according to TT, the results of which showed that the castings are dense, they do not exist slivers, cracks, kinglets, through rips and sinks, as well as identified acceptable and eliminated defects.

The results of this work identified that developed at FSUE «VIAM» and worked in production conditions the technological process of production of GTE parts «diffuser» superalloy VZh 159 provided getting a usable casting. The level of mechanical properties and long-term strength at a temperature close to the operating conditions, shows the possibility of using the superalloy VZh159 as a promising structural material for parts of the stator of an aircraft engine operating at temperatures up to 900°C inclusive.

<p style="text-

Read in Russian

4.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-29-36
УДК 678.741:536.485
Kablov E.N., Semenova S.N., Suleymanov R.R., Chaykun A.М.
PROSPECTS FOR THE USE OF ETHYLENE-PROPYLENE-DIENE RUBBER AS PART OF COLD RESISTANT RUBBER

In the framework of improving the operational characteristics of polymer compositions, ethylene propylene diene rubber was investigated as the main component in the composition of cold-resistant rubber.

Ethylene propylene diene rubber has excellent resistance to oxidation by ozone and oxygen, to light, good physical and mechanical properties, a fairly wide range of operating temperatures, which can be expanded by the introduction of plasticizers or a combination with other thermally and cold-resistant rubbers.

Modern ethylene propylene diene rubbers with a low glass transition temperature ensure the performance of rubbers based on them to a temperature of -60°C.

Domestic rubbers were used in the work: SKEPT-40, SKD-N, SKTFV-803. A comparison of the technical characteristics of the obtained vulcanizates was carried out with the properties of cold-resistant sealing rubber of the IRP 1375 grade containing ethylene-propylene rubber.

For vulcanization of the rubber compound based on SKEPT-40, the optimal vulcanizing system was developed: a mixture of organic peroxide and sulfur in the presence of a sulfenamide accelerator.

It was shown that the finished rubbers had almost twice the elastic strength characteristics compared to IRP 1375, and the addition of a paraffin plasticizer to the rubber composition improved cold resistance of vulcanizate by 5°C compared to the specified rubber.

A method for mixing ethylene propylene diene and siloxane rubbers in the presence of two types of reinforcing fillers: carbon black (P324) and silicon oxide (Aerosil A-300) is proposed.

It is concluded that combinations&

Read in Russian

5.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-37-45
УДК 629.517:699.844
Shuldeshov Е.М.
SOUND-PROOF PROPERTIES OF AVIATION HEATSOUND-PROOF MATERIALS

The requirements shown to heatsound-proof materials of aviation assignment are described. The description of method of determination of sound-proof properties of materials is provided. Two types of porous materials are described: fibrous and cellular. Are designated strong and weaknesses of each type. Are provided on two representatives of each type – domestic and foreign. Comparison of density, heat conductivity, working temperature, hygroscopicity, and also combustibility is provided. It is established that materials of fibrous and cellular types are close according to the main characteristics, however fibrous materials considerably concede on hygroscopicity indicators. Sound-proof properties of heatsound-proof materials without design are provided. The conclusion is drawn on superiority of cellular materials in all the studied range of frequencies. It is noted that according to the received data probably two options of increase of sound-proof properties of heatsound-proof materials: change of structure of material, or addition of layer of bigger density and smaller porosity. Materials of the brands VTI-25 and VTI-25U in which the concept of the second layer is implemented are given. It is shown that application of similar approach allows to increase sound-proof properties to the levels close to materials of cellular type, however density of fibrous material thus raises. It is noted that the way of fastening of layers by means of glued joint is more preferable in comparison with piercing option. The assumption is made that increase of acoustic characteristics is reached at the expense of continuous glue layer which after polymerization are raised by reflection of acoustic waves in material. In case of underrunning through openings on all material thickness that leads to decrease in its sound-proof characteristics are formed.

Read in Russian

6.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-46-54
УДК 667.621
Khaskov M.A., Safronov E.V.
THE OPTIMIZATION OF THERMOSETTING MATRIXES CURING SCHEDULE ON THE EXAMPLE OF COMPLEX SHAPE SAMPLE

The finite difference and finite elements methods are regarded for mathematic simulation of thermoset curing processes on the example of epoxy resin and amine hardener. The finite difference method was used to simulation of flat layer curing and simultaneous solution of heat transfer and chemical interaction problem. The finite element method was used for simultaneous three-dimensional numerical solution of heat transfer, chemical interaction and stress-strain problems during curing of complex-shape samples. The verified kinetics model obtained from differential scanning calorimetry was used. The literature data of the parameters of heat transfer, chemical shrinkage and thermal expansion were used for calculations.

Read in Russian

7.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-55-66
УДК 669.018.95
Karashaev M.M., Lomberg B.S., Bakradze M.M., Letnikov M.N.
ON TECHNOLOGICAL APPROACHES TO THE CREATION OF COMPOSITE MATERIALS BASED ON NICKEL MONOALUMINIDE NiAl (review)

The article discusses the main technological features of the formation of natural and artificial composite structures based on NiAl compounds. It is shown that this kind of materials can be obtained by directional crystallization methods and by technology, including thermomechanical processing, as well as using mechanical activation methods followed by controlled reaction synthesis, forced and reaction impregnation with a matrix-forming melt, and deformation-diffusion solid-phase combination. Some experimental and theoretical calculations based on multicomponent state diagrams that allow the creation of such materials using the above methods are presented and generalized. Based on the data obtained, conclusions are drawn about further paths in the development and creation of materials based on nickel monoaluminide NiAl.

As a result of a review of the works, it was found that, with respect to the processes of directed crystallization and the traditional preparation of a given chemical composition of natural compositional structures based on β-phase NiAl by smelting of ingots, it is necessary to use state diagrams in order to form an optimal alloying system that provides the required final material structure and , respectively, the necessary mechanical properties, taking into account the thermal and thermomechanical processing. All this determines the need for a set of theoretical and practical work to create a reserve for the development of structural materials based on systems with a NiAl matrix that operate at elevated temperatures both as turbine disks and as GTE blades.

A significant advantage of artificially created composite materials is their versatility, in particular, allowing the formation of the necessary artificial structures with a matrix on the basis of various intermetallic compounds, including NiAl, with predetermined properties capable of wo

Read in Russian

8.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-67-79
УДК 678.747.2
Valueva M.I., Zelenina I.V., Zharinov M.A., Akhmadieva K.R.
WORLD MARKET OF HIGH TEMPERATURE POLYIMIDE CARBON PLASTIC (review)

In addition to high-strength carbon plastics at a working temperature of up to 150 °C, for highly loaded parts of aircraft, when creating a new generation of equipment, it is necessary to use polymer composites in heat-loaded structural elements at temperatures up to 250-300 °C. Based on an analysis of literature, a review of information on the world market of high-temperature carbon plastics based on thermosetting binders with imide cycles is presented.

It presents economic trends, information about the participants in the global market for high-temperature carbon plastics, as well as the high-temperature auxiliary materials necessary for their production. The supply chain of the market for high-temperature polymer composites includes suppliers of raw materials, manufacturers of high-temperature resins, manufacturers of prepregs and compounds, manufacturers of structures and aircraft (final product).

For the period until 2023, a stable growth rate of the market of high-temperature polymer composites is forecasted. The large market for high-temperature polymer composites is the Asia-Pacific region, the main growth factors of the market in North America are the intensive development of the aerospace industry in the region, while the automotive industry is the main driver in Western Europe.

A description of the materials of the companies Cytec Solvay Group (USA), Hexcel (USA), Teijin (Japan), Evonik (Germany), Renegade Materials Corporation (Maverick Corporation) (USA), UBE Industries Ltd (Japan), TenCate Advanced Composites (Toray), Nexam Chemical (Sweden), presents information about Russian developments.

In connection with the increasing requirements for materials intended for use in the latest aircraft products, there is a need for a qualitative improvement of materials, increasin

Read in Russian

9.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-80-87
УДК 621.357.7
Salakhova R.K., Tihobrazov A.B., Smirnova T.B.
ON THE PROCESS OF ELECTROCHEMICAL COPPER DURING REPAIR OF PARTS FROM TITANIUM ALLOYS

The article presents a brief overview of the state of the issue in the field of electrochemical treatment of titanium alloys, in particular in the restoration repair of the geometric dimensions of worn parts. The advantages of the proposed method of repair over the traditionally used chrome plating repair technology are considered.

Alkaline pyrophosphate copper plating electrolytes were selected for deposition of copper coatings on samples of titanium alloy VT6, as the most technologically advanced and environmentally friendly.

A method of surface preparation of titanium alloy VT6 through the operation of preliminary Nickel plating, providing the adhesion strength of the copper coating with a titanium substrate and eliminating the hydride etching of titanium in a mixture of concentrated acids. The technological modes of thick-layer copper plating of VT6 titanium alloy (coating thickness of at least 100 μm) were tested and the deposition rate of the copper coating in pyrophosphate electrolytes at the limiting current was determined. The thickness was determined by a metallographic method and the microhardness and roughness of a copper coating obtained in a copper plating electrolyte based on potassium pyrophosphate were studied.

The method of temperature change in accordance with GOST 9.302 and the method of impact using a vertical copra «Constant U-2M» assessed the adhesive strength of the combined coating «copper-chrome», for comparison in the same way tested the adhesion strength of chrome coating thickness of over 100 microns, as a coating analogue. The adhesion strength of the coatings measured by the heating method meets the requirements of GOST 9.302, copper-chrome and chrome coatings withstand the impact energy up to 9.8 J. Metallographic examination of the impact zone revealed microcracks in

Read in Russian

10.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-88-98
УДК 543.6
Dvoretskov R.M., Uridiya Z.P., Karachevtsev F.N., Zagvozdkina T.N.
DETERMINATION OF THE CHEMICAL COMPOSITION OF MAGNESIUM ALLOYS BY THE ATOMIC EMISSION SPECTROMETRY WITH INDUCTIVELY COUPLED PLASMA

The growing demand for magnesium alloys is determined by their low density and at the same time quite high strength. Complex alloying of magnesium alloys of Al, Mn, Zn, In, Cd, Li, Bi, Zr, Nb and REM allows to achieve a significant increase in corrosion resistance and improve mechanical and heat-resistant properties. Spectral analysis methods are used for analytical control of complexly alloyed metallurgical objects. The advantages of inductively coupled plasma atomic emission spectrometry (ICP AES) are, among others, graduation using standard solutions of pure elements and the ability to verify correctness using model solutions, which is especially important in the case of analysis of new alloys by reason of the lack of necessary reference materials. To ensure high accuracy and efficiency when using this method, it is necessary to develop measurement technique. In this paper, we propose ICP AES technique for determining alloying elements in magnesium alloys. Analytical lines of elements free from significant spectral overlays were selected. The limits of detection and determination of elements are estimated. The efficiency of using the spectral lines of scandium, rhodium, and barium as elements for internal standardization under conditions of changing plasma power, argon spray flow, and solution feed rate into the spray chamber is studied. Barium is selected as the preferred internal standard. Studies of the metrological characteristics of the method using model solutions were carried out: for element contents above 0.005% by mass. the repeatability does not exceed 3% relative, and the precision does not exceed 5% rel. The correctness of the developed method was verified using certified reference materials of magnesium alloys and the «entered-found» method. The developed ICP AES technique for determining Al, Mn, Zn, In, Cd, Li, Bi, Zr, Nb can be used to determine the composition of modern magnesium alloys such as VML and&

Read in Russian

11.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-99-108
УДК 620.1:678.747.2
Gulyaev A.I., Yakovlev N.O., Oreshko E.I.
FRACTOGRAPHY FEATURES OF INTERLAMINAR CRACK GROWTH IN CARBON FIBRE REINFORCED PLASTIC UNDER VARIOUS MODE LOADING

Particular attention has been paid to the issues of damage accumulation and fracture of polymer composites in recent decades. One of the critical characteristics of polymer laminates is the resistance to the initiation and propagation of interlayer cracks. An urgent task is to identify fractographic signs of interlayer crack growth under regulated loading conditions in order to use the identified characteristic elements of fracture microrelief as diagnostic signs of operational fracture of PCM structures. The object of the study in this work was unidirectional carbon fiber based on high strength fibers and an epoxy binder modified with polysulfone. The interlayer crack resistance characteristics were experimentally determined under conditions of normal opening (mode I), forward shear (mode II), and combined loading (at various opening and shear ratios) of unidirectional epoxy polysulfone carbon fiber reinforced plastic. Based on the results of fractographic analysis, the characteristic fracture microrelief elements are identified and their transformation is presented when the interlayer crack growth conditions change: from opening through combined loading to forward shear. The fracture microrelief in the zone of the epoxy thermoset continuous phase and in the zone of the thermoplastic continuous phase with spherical epoxy domains varies significantly. The separation plateau in the interfiber space passes into the zones with a creep topography with a 70% opening contribution, then into the cusps with a tufted feet at the 40% opening contribution, and finally become the pure shear cusps. In the thermoplastic continuous phase zone, with an increase in the contribution of the shear to the conditions of crack opening, the increasing effect of smearing the plastic phase of polysulfone on relatively rigid epoxy domains is manifested. On the compressed side of the fracture, the direction of smearing coincides with the direction of growth of t

Read in Russian

12.
dx.doi.org/ 10.18577/2307-6046-2019-0-12-109-118
УДК 66.045.3:678.6
Zarichnyak Yu.P., Razmakhov M.G.
PREREQUISITES FOR THE SELECTION OF THE STRUCTURE MODEL OF HIGHLY POROUS FIBROUS MATERIALS TO TAKE INTO ACCOUNT THE INFLUENCE OF TECHNOLOGICAL FACTORS AND THE CALCULATION OF HEAT TRANSFER

The main advantage of thermal conductivity calculation using structure models is its application for solving materials science problems. This approach allows us to obtain the dependence of the characteristics of the structure on the parameters of the technological process, on the processes of interaction of components and phase transformations, and to determine their relationship with the main operational characteristic of thermal insulation materials-thermal conductivity.

The results of measurement and calculation of thermal conductivity of anisotropic highly porous material on Al2O3·SiO2 fibers in the temperature range from 20 to 1700ºC are presented in the proposed work. Anisotropy of structure and properties formed as a result of forming tiles from semi-finished fibrous material with non-fixed contacts. The measurement results were obtained by stationary method on cylindrical samples and pulse method provided that the sample is in an opaque container. To process the measurement results obtained by the stationary method on cylindrical samples, the axial heat flows in the sample and the heater were taken into account, to process the measurement results by the pulse method, a mathematical model was developed, the inverse problem of radiation -conductive heat exchange was solved. The calculation assumes no convection.

Read in Russian