Articles

 


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1.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-3-14
УДК 544.344:621.762:669.245
Kablov E.N., Letnikov M.N., Ospennikova O.G., Bakradze M.M., Shestakova A.A.
PARTICULARS OF THE PRECIPITATION STRENGTHENING γʹ-PHASE DURING AGING OF HEAT-RESISTANT WROUGHT NICKEL SUPERALLOY VZh175-ID

Mechanical properties of nickel superalloys for gas-turbine engine disks depends on the size, morphology and character of the distribution γʹ-phase in the γ-solid solution, after complete heat treatment.

During the heat treatment of large-sized disk forgings, the cooling conditions during quenching in thin and massive sections of forgings can differ greatly, which will lead to an inhomogeneous distribution of the γʹ strengthening particles through volume of the workpiece and reduce the mechanical properties. This paper is presented the features of the formation of γ strengthening particles in VZh175-ID heat-resistant wrought nickel superalloy during aging, depending on the cooling rate during quenching.

Quantitative analysis of secondary and tertiary γʹ-phase in VZh175-ID superalloy after quenching with cooling rates of 340 and 58°C/min and subsequent aging for 10 hours at various temperatures is carried out. For each state, microstructures and histograms of the distribution of secondary γʹ-phase are given. The changes in the average size of the secondary g¢-phase for each cooling rate during quenching and the aging temperature are shown. The dependence of the yield strength at 20°C with the size of the tertiary phase is shown. The results of stress to rupture tests at temperature of 650°C of the samples after quenching with cooling rate of 340°C/min and aging at different temperatures are presented.

The results of this study are shown that the excellent strengthening effect in the VZh175-ID nickel superalloy is achieved in the case of rapid cooling from the quenching temperature and subsequent aging at temperatures below or near the γʹ-phase dissolution start temperature.

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2.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-15-25
УДК 669.245
Kuzmina N.A., Lifshitz V.A., Potrakhov E.N., Potrakhov N.N.
COMPARATIVE STRUCTURE CONTROL OF SINGLE-CRYSTAL CASTINGS OF NICKEL SUPERALLOYS X-RAY DIFFRACTION METHODS OF OSCILLATION AND LAUE

Single-crystal turbine blades made of Nickel heat-resistant alloys are very sensitive to the degree of structural perfection. The quality of the structure of the single crystal has an impact on the strength and plastic characteristics of the products from the nickel-base superalloy and is the most important technological criterion that determines the yield of usable products and its cost. The article compares the possibilities of two x-ray methods of mass control – the method of swing on the DRON-4 diffractometer and the method of Laue on the installation of PRDU in relation to assessing the quality of the structure of single-crystal castings.

The standard slit of the diffractometer DRON-4. allow the production of turbine engine blades to test the priming, growth cones and samples for mechanical testing of different geometric sizes. In the absence of blocks (subgrains), both x-ray methods give almost the same result of the measurement of the axial component of the crystallographic orientation, i.e., the deviation of the given crystallographic direction from the optical axis of the device combined with the investigated direction in the sample; shooting of one sample takes approximately the same time. Therefore, both methods can be used for mass control of the size of the crystallographic orientation of the seed needed to obtain a single-crystal structure of the blades, growth cones and samples of nickel-base superalloy.

When a block substructure is detected at the stage of visual inspection of growth cones, it is necessary to determine the axial component of the block misdirection by the "swing" method on an x-ray diffractometer of the DRON- type.  Provided that the axial component of the disorientation does not exceed the required technical conditions, the casting can be further tested by Laue. This will allow us to determine the azimuthal orientation

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3.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-26-37
УДК 669.295
Ospennikova O.G., Lukin V.I., Afanasiev-Khodykin A.N., Galushka I.A.
TECHNOLOGY OF THE HIGH TEMPERATURE DIFFUSIVE BRAZING OF A BIMETALLIC «BLISK» DESIGN

The article presents the work on developing manufacturing technology for the «blisk» design made of bimetallic nickel-based superalloys (the disk from deformable EP975 and blades from single-crystal VKNA-25), with the high-temperature diffusion brazing. During the work temperatures of brazing and heat treatment of the product, that considers it technological features during the work and selected combination of materials has been selected. Designed brazing alloy at selected brazing temperature, has an optimal set of technological characteristics.

Studies of EP975 and VKNA-25 brazing joints, with brazing alloy VPr56 showed that the microstructure in brazing joint has a complex multi-component structure that consists of grains g solid solution and a complex eutectic layer in the center of the solder seam that consists of a solid solution.

The study of the effect of homogenizing heat treatment on the microstructure of brazing joint showed the result of diffusion exchange between the structural component of brazing joint and joined materials showed, as a result, it formed an aligned between them. An increase of exposure of homogenization treatment showed a smooth gradient between concentrations of alloying elements of materials that were joined without forming excessive and non-equilibrium phases.

The strength determining of brazing joint of EP975 and VKNA-25 in bimetallic combination with optimal homogenization thermal treatment showed the long-term strength of solder joints at a temperature of 975°C on the level of 313–352 MPa, which corresponds to a strength of 0,8–0,9 from the strength of the material EP975.

The obtained research results were applied in the manufacture of a bimetallic specimen of a «blisk&am

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4.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-38-46
УДК 669.295
Zakharova L.V.
SOLID-METAL EMBRITTLEMENT OF TITANIUM ALLOY VT20 IN CONTACT WITH SILVER, ZINC AND CADMIUM

The phenomenon of solid-metal embrittlement of titanium alloy VT20 in contact with silver, cadmium and zinc was considered. The influence of such factors as the contact density of the titanium surface with the metal, the temperature and duration of the tests, as well as the application of external tensile stresses were investigated.

It was established that the temperature cracking threshold of titanium alloy VT20 in contact with the silver is about 270°C, and under the influence of the zinc coating is not more than 150°C. However when titanium alloy VT20 contact with galvanized titanium foil temperature cracking threshold is 250°C and can be detected in the result of long test for 500 hours at a stress σ=0,9σ0,2. When the applied stress level or the duration of the test at 250°C are reduced, no cracking in contact with the galvanized foil is detected. Since in real conditions the influence on titanium parts is possible only from the contacting galvanized steel parts, the contact of titanium and galvanized steel parts can be considered acceptable at operating temperatures not higher than 250°C.

It was found that close contact with cadmium can cause solid-metal embrittlement of titanium even at 20°C and in the absence of external tensile stresses. Under the influence of the contact pressure in the absence of external tensile stresses the incubation period of crack nucleation in contact with cadmium is very small and decreases with test temperature increase: at 20°C – not more than 25 h, at 60°C – less than 10 h, at 100°C – no more than 2 hours. It was established that the application of external tensile stresses intensifies cracking and reduces the incubation period.

The specific structure of the focal zone of cracking in the fractures of the samp

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5.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-47-56
УДК 665.939.5
Petrova A.P., Lukina N.F., Rubtsova E.V., Isaev A.Yu.
THE EFFECT OF REINFORCING EPOXY FILM ADHESIVE VK-51 WITH NON-WOVEN FIBROUS MATERIAL ON ITS PROPERTIES

The influence of the type of reinforcing filler in the composition of the film adhesive VK-51 on the properties of adhesive joints based on it. To compare the properties of adhesive joints made with application of glue VK-51 without fibrous filler.

The use of the adhesive composition VK-51 of the reinforcing filler leads to a decrease in the strength of adhesive joints during shift, this increases the strength at peeling, which is important to the health of glued laminates when exposed udiraya loads.

Comparing the properties of the adhesive joints obtained with the use of adhesives VK-51A containing, as reinforcement two types of reinforcing fillers, it is determined that when used in the adhesive composition of the canvas only on the basis of Mylar fibers, one can obtain the higher shear strength of the adhesive joints at elevated temperatures, and resistance to water and tripicolinate compared to the glue, obtained using the canvas only on the basis of Mylar fibers.

The presence of a reinforcing fibrous filler for glue VK-51A viscose fibres leads to a decrease of the strength characteristics of the adhesive joints. When used in the adhesive composition VK-51A reinforcing filler cloth on the basis of Mylar fibers provides increased durability of the adhesive joints under shear at an elevated temperature, as well as improving their water resistance and tripicolinate.

With the aim of increasing the duration of the gap between the operations of anodizing and bonding directly after anodization, the prepared surface is applied to adhesive soils, through the application of which increases the gap between the process until at least 30 days.

The application of primer EP-0234 as a sublayer under the high-strength film adhesive VK-51 and MC-51A does not reduce t

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6.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-57-63
УДК 665.939.5
Petrova A.P., Lukina N.F., Isaev A.Yu.
OPERABILITY OF GLUED JOINTS ON EPOXY FILM ADHESIVES AT SIMULTANEOUS INFLUENCE OF LOADINGS AND CLIMATIC FACTORS

Test results of glued joints of the D19-AT aluminum alloy executed using epoxy film adhesives VK-31, VK-41M and VK-51, after exposure within 5 years in the conditions of subtropical climate of the coast of Black Sea in free and loaded condition are provided. The adhesives joints made using VK-31 glue, have high climatic firmness: after endurance without loading within 5 years, both on open atmospheric area and in warehouse their durability has decreased ~ for 6%. The glued joints executed using VK-41M adhesive, in initial condition have durability ~ for 4,5% below, than adhesived joints on VK-31 glue. After influence of weather conditions of open atmospheric area without loading within three years their durability has decreased ~ for 20% in comparison with 4,5% for VK-31 glue, at simultaneous influence of loadings and climatic factors: at level of loading 0,2 from initial durability decrease makes in 2 years for 17%, and in 3 years for 19%. In the conditions of warehouse decrease in durability of adhesived joints is lower, than on open atmospheric area.

VK-51 adhesive is strongest of three considered glues, thus its mode of curing similar to VK-41M glue. After endurance of adhesived joints on open climatic area within 3 years decrease in durability of glued joints at the room temperature has made 12 %, at temperature 80°C – 28%. At tests of adhesived joints under loading 0,2 from initial durability decrease in durability makes 24,6% at temperature of testing of 20°C and 32 % at 80°C. Putting EP-0234 soil under VK-51 glue promotes durability preservation at the room temperature in initial condition, to increase of durability of characteristics at testing temperature 80°С, and also to saving of higher strength characteristics at simultaneous influence of weather conditions and loadings.

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7.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-64-72
УДК 678.7
Semenova S.N., Suleymanov R.R., Chaykun A.М.
MIXING ETHYLENE-PROPYLENE-DIENE AND METHYLPHENYLSILOXANE RUBBERS IN THE FORMULATION OF COLD AND OZONE RESISTANT RUBBER

Improving the performance of special polymer compositions is an important work direction of FSUE "VIAM". It is actual to create cold-resistant materials resistant to climatic factors: temperature extremes, ozone and air oxygen.

In the present work we investigated the possibility of obtaining ozone-resistant and cold-resistant rubber based on ethylene-propylene-diene (SKEPT-40) and methylphenylsiloxane (SKTFV-803) rubbers.

The choice of rubbers is associated with high mechanical characteristics and good low-temperature properties of SKEPT, a wide range of operating temperatures and excellent indicators of residual deformation under compression of SKTFV, as well as their high ozone resistance.

It is known that ethylene polypropylen diene and siloxane rubbers, having different chemical nature, are poorly compatible in the mixture. In literature the ways of effective mixing in the presence of binding agents, such as polydiorganosiloxane resins, silanes are described. To improve compatibility nanoclay was used. Also joint curing of two layers of material was carried out, in one of which silicone rubber, and in other – ethylene polypropylen diene rubber were prevailed.

This work was carried out in a mixture of EPDM and SKTFV in the presence of two types of reinforcing fillers. On the basis of the dispersion analysis of vulcanizates it is concluded that the quality of mixing is satisfactory.

As a result of measurements of elastic strength and heat-cold-resistant characteristics, the optimal ratios of rubbers in the rubber mixture and the vulcanizing system are proposed.

It is shown that the investigated rubber based on EPDM and SKTFV has improved physicomechanical and&

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8.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-73-79
УДК 678.747.2
Malakhovskiy S.S., Mishkin S.I.
THE MAIN TRENDS OF RECEIVING AND APPLICATIONS SECONDARY CARBON FIBRES (review)

Currently, taking into account the active use of polymer composite materials (PCM) in virtually all sectors of the industry of the Russian Federation (construction industry, transport engineering, transport infrastructure, energy, utilities, etc.), the question of their safe disposal is becoming acute. Carbon fibers, contained in PCM, is an expensive raw material that must be removed from the out-of-service products and reused.

The paper discusses the main methods of recycling carbon fiber-reinforced PCM: physical, chemical and thermal. The basic methods of PCM processing are described, both positive and negative sides of each method are noted. A domestic PCM recycling method is also provided. From the literature data it has been shown that solvolysis and pyrolysis remain the most promising ways of recycling composite materials.

The main way to solve the problem of PCM utilization is their recycling. The article provides foreign firms engaged in the processing of products and materials, the source of raw materials of which are defective parts, products with expired shelf life, trimming, unused prepregs. Showing intermediary firms that produce specific products from recycled fiber: the bottom of the car body, interior, composite vessels and much more.

Analysis of foreign scientific and technical literature and existing methods of using secondary carbon filler showed the relevance of work in this area of materials science. More and more countries are interested in reducing the consumption of oil resources and the transition to energy-intensive and resource-saving technologies. Many companies in the EU, the USA and the UK are engaged in the processing of PCM and the extraction of expensive carbon-reinforced filler.

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9.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-80-88
УДК 678.8
Gunyaeva A.G., Veshkin E.A, Antyufeeva N.V., Panafidnikova A.N., Efimik V.A.
RESEARCH OF INFLUENCE OF THE CONDENSATION MOISTURE ON CARBON FIBER PLASTIC PREPREG ON THE BASIS OF SOLUTION EPOXY BINDER AND PСM ON ITS BASIS

Modern production of junctions and structures made of polymeric composite materials (PCM) for aviation equipment is majority based on prepreg technology of manufacturing products. Prepregs are semifinished PCM. During storage properties of prepreg tend to change under the influence of various factors (chemical, physical, biological).

The article considers the influence of storage conditions, including condensation moisture, on its reactivity and properties of the rejected PCM based on the example of prepreg PU-4E-2m used in the mass production of aircraft products. Prepreg PU-4E-2m is made on the basis of a carbon tape ELUR-P and a solution epoxy binder ENFB-2M. Designed for the manufacture of parts and assemblies for structural purposes, operating in the temperature range from minus 60 to plus 150 °C. The methods of thermal analysis were choosen as the main method for the analysis

For research a batch of ENFB-2M binder and a batch of prepreg PU-4E-2m based on it were made, their properties were investigated.

To assess the effect of condensed moisture, which can be formed on the prepreg during storage, its effect on the reactivity of the prepreg PU-4E-2m by differential scanning calorimetry (DSC) after its multiple freezing was made, which takes place in the conditions of mass manufacture of products from PCM.

The influence of the storage time (1 and 3 months) of prepreg PU-4E-2m at a temperature of not more than minus 18°C on the properties of the resulting carbon fiber CMU-4E-2m, including after accelerated climatic tests (boiling), was done.

The case of violation of storage conditions of prepreg in the process of its thermostating – defrosting (exposure) at room temperature before the beginning of the technological process of laying out

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10.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-89-99
УДК 539.262
Nazarkin R.M.
SMALL-SIZED X-RAY DIFFRACTOMETERS FOR STRUCTURE AND PHASE ANALYSIS PURPOSES (review)

The high-priority problem for material physics at the present time is the investigation of dependency of physical and mechanical properties from crystal structure and phase composition. The research methods of materials structure are divided into two main groups: the diffraction methods and the microscopical methods. The diffraction methods of analysis, such as X-ray diffraction analysis, make possible the determination of the crystal lattice parameters to a high-precision and, also, the qualitative and quantitative phase analysis of materials.

Also, by use of the diffraction methods of analysis, the texture of polycrystalline materials and the crystallographic orientation of single crystals are determined. There are principal for the investigation of anisotropy of the physical and mechanical properties.

The determination of stress condition is required for predicting behavior of materials and facilities under service conditions. The macroscopic stresses in the material – environment interface of the polycrystalline materials may be determinate by non-destructive technique – the X-ray diffractometry.

There are all the above problems requested the use of special scientific instruments i.e. the X-ray diffractometers. The X-ray diffractometer be capable of automatized record of X-ray diffraction patterns as a diagram «X-ray radiation intensity» – «2θ diffraction angle». The X- ray diffractometer be made up of X-ray tube, X-ray goniometer and X-ray detector.

The small-sized X-ray diffractometers with various designs were developed for improved equipment of industrial, research and educational laboratories by domestic and foreign manufacturing companies, which produced scientific instruments. The small-sized X-ray diffractometers are designed to b

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11.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-100-107
УДК 620.1:678.8
Laptev A.B., Golubev A.V., Kireev D.M., Nikolaev E.V.
TO THE QUESTION OF BIODEGRADATION OF POLYMERIC MATERIALS IN NATURAL ENVIRONMENTS (review)

In the course of research, the exposition of samples of steel, polystyrene and PET in water of different mineralization and in different climatic zones was carried out. The study of samples allowed to evaluate the stages of biofouling and biodegradation based on the analysis of mechanical properties of deposits on the surface.

It is established that at the first stage under the action of algae the surface of the samples is oxidized by oxygen released during photosynthesis of algae and their curing. At the second stage, after 30-40 days of exposure, the polymer samples are saturated with moisture and the surface is destroyed by bacterial exchange products, which leads to a drop in both strength and plasticity of polystyrene and polyethylene terephthalate samples.

For metal samples in the coastal waters of the Black sea, one of the most aggressive groups of microorganisms are organisms of the invertebrate species — marine sponges of Calcispongiae class, which are the first to attach to the surface. The products of their metabolism cause local acidification of water with carbon dioxide, which causes the destruction of samples and the formation of deposits in the form of calcium salts.

Methods of molecular biology in biological samples taken from samples of materials in Ufa, the most active representatives of the genera Pseudomonas and gammaproteobacteria Aeromonosis, as well as genera betaproteobacteria Acidovorax and Hydrogenophaga; in samples taken from samples in Gelendzhik – general alfaproteobacteria Erythrobacter, Marivita and Alterythrobacter; in samples taken from samples in D. goretovo is a genus of betaproteobacterium aquabacterium. Since it is for the representatives of the genus Pseudomonas, according to the literature, the ability to degrade PET, they, and possibly Acidovorax, can be bacteria-destructors

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12.
dx.doi.org/ 10.18577/2307-6046-2019-0-9-108-126
УДК 66.017:620.1
Oreshko E.I., Erasov V.S., Grinevich A.V., Shershak P.V.
REVIEW OF CRITERIA OF DURABILITY OF MATERIALS

In work the analysis of various criteria of durability for isotropic, orthotropic and anisotropic materials is carried out. Applied approaches are described at calculation of durability of fibrous and layered composite materials. Criteria are considered: Mises, Pisarenko-Lebedev, William-Varnke, Druker–Prager, Bazant, Norris, Kuntts, Goldenblat–Kopnov, Tsai–Hill, Tsai–Wu, Hashin, LaRC, Hoffman, Puck, criteria of durability sandwich of panels, etc. The review of models of durability of the materials used in the ANSYS Mechanical APDL program is presented.

It is noted that to modeling of designs from composite materials apply some main ways: structural, phenomenological and combined. At a structural approach the structure of a material and micromechanical interaction between separate elements of components is considered when loading all design. At a phenomenological method the non-uniform composite material is considered as an averaged continuous material - homogeneous anisotropic. The combination of these two methods will be intermediate. In a structural and phenomenological method idealized describe behavior of a monolayer, but a multilayered composite material describe compound, including separate layers (estimate properties of heterogeneous systems through physicomechanical properties of the separate phases making this system).

In the analysis of durability of multilayered covers according to structural phenomenologically method at first receive averaged physicomechanical characteristics then there is a calculation of the design consisting of covers. By mathematical model define distribution of tension and deformations in a design. Then pass from averaged deformations and tension in composite covers to tension and deformations in each monolayer of a composite material, on the basis of its properties, orientation of fibers, thickness and situation in a package. In the final stage on the basis of the received values the conc

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