Articles

 


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1.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-3-10
УДК 543.51; 669.1
Alekseev A.V., Yakimovitch P.V., Legkodukhova I.S.
DETERMINATION OF LOW CONTENTS (LESS THAN 0,0005%) OF ARSENIC IN NICKEL ALLOYS BY ICP-MS AND AAS METHODS WITH ELECTROTHERMAL ATOMIZATION

At present, nickel alloys are widely used in various industries (aircraft construction, engine construction). These materials are characterized by increased heat resistance, heat resistance, as well as high mechanical strength, which makes it possible to use products made of these alloys at high temperatures reaching 1050 °C.

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.

Inductively coupled plasma mass spectrometry (ICP-MS) is a multi-element method for the determination of impurities in various materials. The method allows the simultaneous determination of a large number of elements and is characterized by low detection limits, simplicity of sample preparation using microwave decomposition of a sample in a mixture of acids. However, direct determination of arsenic in cobalt-doped alloys is difficult due to the presence of spectral interference (superposition) of the signal from 59Co16O+ with the signal from 75As+. When arsenic is determined in chromium, there is an interference of 40Ar35Cl+ with 75As+, because hydrochloric acid is needed to dissolve chromium. In this work, the determination of low contents (less than 0,0005 wt.%)

Of arsenic in complex-alloyed samples of nickel alloys by means of inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption (AAS) spectroscopy with electrothermal atomization was carried out. These methods also determined the content of arsenic in chromium, which is an alloying component of nickel alloys. A technique for dissolving a sample and preparing it for analysis is presented. Spectral interferences are eliminated by ap

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2.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-11-20
УДК 621.762
Knyazev A. E., Vostrikov A.V.
SIEVING OF POWDERS ADDITIVE AND POWDER MANUFACTURINGS (review)

The paper considers the features of powders obtained by various methods, their technological properties in relation to additive and granular production. The sequence of operations upon receipt of metal powder compositions is presented. The factors affecting the process of vibration sieving of metal powders and granules are described. The features and advantages of vibratory sieving on horizontally arranged circular sieves using ultrasonic cleaning to obtain specified trajectories of motion are shown. Criteria for evaluating the sieving efficiency are given and explanations are given for determining the particle size distribution of powders and granules.

The preliminary operation after gas atomization before screening is an aerodynamic separation operation, which removes fine and fine fractions, which improves technological properties and facilitates subsequent screening;

The most preferred for industrial screening of powders used in additive manufacturing and granular metallurgy is the use of round sieving machines (vibrating screens) with a horizontal arrangement of sieves providing the greatest efficiency;

Creation of complex trajectories during sieving on horizontal circular sieves makes it possible to increase the percentage of extraction of the target fraction, as well as apply more compact installations without loss of productivity and efficiency;

In order to obtain the target granule fractions with high yield used in additive production and in the production of gas-turbine disc blanks by granular metallurgy, it is necessary to use special equipment to ensure high process and technology productivity.

When sieving powders with a particle size of less than 40–63 μm, plants should be equipped with continuous cleaning systems, the most prefer

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3.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-21-30
УДК 669.715
Benarieb I., Romanenko V.A., Klochkova Y.Y., Ovchinnikov V.V., Sbitneva S.V.
APPLICATION OF HIGH-TECH ALUMINUM ALLOY V-1341 OF Al–Mg–Si SYSTEM FOR PIPELINES OF AIRCRAFT PRODUCTS

This paper presents the results of industrial manufacturing technology development of cold-worked drawn seamless thickness tubes from aluminum alloy В-1341 of Al–Mg–Si system (6xxx series) with additions of calcium. Alloy В-1341 tubes are for applications in hydraulic and air conditioning systems of aircrafts.

The results of analysis of structure and mechanical properties of tubes that have influenced by heat treatment and manufacturing are presented. Because of high workability of alloy at cold rolling and tube drawing carrying out additional intermediate annealing was not required.

Complex researches of structure and properties of tubes Æ10×1,0, Æ25×1,0 and Æ50×1,5 mm in size are conducted. After strengthening thermal processing on tubes the fine grained recrystallize structure with average grain size from 20 to 40 microns was created.

The tubes made on developed technology, have high level of mechanical properties (σв=355 МПа, σ0,2=310 МПа, δ=13%) in combination to high corrosion resistance and plasticity at cold morphogenesis. Tubes have high technological ductility at the first 6 hours after quenching hardening that allows to make of them by means of cold forming elements of pipelines difficult on configuration.

The evaluation of weldability of alloy by automatic argon arc welding and resistance spot welding when manufacturing elements of  pipelines connections is carried out.

Pressurization is evaluated and comparison tests on strength by hydraulic pressure are carried out. High strength and pressurization of detachable joints and welded sites of tubes with internal working pressure is established.

Comparison of charact

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4.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-31-37
УДК 678.5
Semenova S.N., Chaykun A.М.
HIGHLY HEAT-RESISTANT SILICONE RUBBER COMPOSITIONS (review)

The development of heat-resistant and fire-resistant cushioning materials and sealing materials is of great interest for the aerospace, automotive, marine, gas, petroleum and defense industries. Innovative developments of FSUE «VIAM» are dedicated to the creation of new generation materials. The review presents modern developments of silicone rubber compositions with increased heat resistance, including those with fire-resistant properties. The retrospective is designed to help in the creation of new silicone rubbers with improved performance properties.

The heat-resistant properties of silicone compositions can be improved due to the polymer base and heat-stabilizing additives. The presence of phenyl groups in the structure of rubber increases the resistance of rubbers obtained on its basis to thermal oxidation. Siloxane block copolymers have unique heat resistance properties.

Heat-stabilizing additives are traditionally metal oxides. In modern developments, preference is given to red iron oxide and cerium oxide. To enhance the heat resistance of the material, combinations of metal oxides with other additives, such as compounds based on isoindolinone, are used.

The heat-resistant properties of silicone rubber may be affected by fillers. The advantage of fumed silica fillers in comparison with the precipitated silica and natural silica is established. It is noted that carbon black improves the heat resistance and fire resistance of rubber.

To obtain both heat-resistant and fire-resistant silicone compositions, a combination of heat stabilizers and flame retardants is used. In modern developments, platinum compounds are mainly used as flame retardants, as well as flame retardants enhanced with a synergist, such as melamine phosphate with lanthanum oxide.

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5.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-38-47
УДК 678.067.5:614.814.41
Shuldeshov Е.М., Nazarov I.A., Ivanov M.S., Donskih I.N.
DECORATIVELY FINISHING MATERIALS FOR WALL PANELS OF PASSENGER CAB AND THE CREW COCKPIT OF AIR VEHICLES (review)

Article is devoted to decorative and finishing films and the decorative tkaneplenochny materials applied to manufacturing of wall and ceiling and panels, and does not mention questions of development and application of paint and varnish materials. The purpose of this work is the assessment of the reached level of development of decortivno-finishing materials in our country and abroad, and also definition of the main tendencies of development of such materials. Assignment of the decorative materials applied in salons and crew cockpits of air vehicles is described. Are provided shown to decorative and finishing films and decorative tkaneplenochny materials of the requirement which performance is necessary for the admission to application in aviation engineering. Short historical data on materials available in our country are provided. Importance of development of the similar materials, developed is designated now. The principle of division of layers of similar materials is described and the list of the options of execution demanded at present is provided. Functions of each layer are investigated and most often applied options of execution, and also options of exception/association of layers meeting in practice are specified. Three ways of manufacturing of decorative materials most popular now, with the indication of specific examples of implementation, and also got advantages are given. Are in detail described, with analysis of specific examples, options of improvement of characteristics both separate layers, and decorative materials or designs with their application. The great attention is given to options of increase of fireproof properties of decorative materials, and also ways of improvement of technological effectiveness and giving to materials of other properties, such as the increased bacteriemic firmness, etc. Information on films of Schneller firm of the USA which according to authors occupy now one of leading positions in this

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6.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-48-59
УДК 677.499
Doriomedov M.S.
ARAMID FIBER MARKET: TYPES, PROPERTIES, APPLICATION

The article is devoted to the consideration of the world and Russian market of aramid fiber. Provides information about the approximate production of aramid fibers in general and by types: para- and meta-aramid. The main trade names of aramid fibers, production facilities, main aramid producers in the world and in Russia, information about the properties of some brands of aramid fiber and indicative percentages of various fields of application in the global and Russian consumption of aramid fibers are given.

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7.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-60-67
УДК 669.018.95
Nyafkin A.N., Shavnev A.A., Serpova V.M., Razmakhov M.G., Pahomkin S.I.
INVESTIGATION OF IMPACT OF VACUUM HEAT TREATMENT ON THERMOPHYSICAL PROPERTIES OF COMPOSITE MATERIAL OF Al–SiC SYSTEM WITH HIGH CONTENT OF REINFORCING PHASE

The article is devoted to the study of the effect of vacuum annealing of MCM based on aluminum casting alloy AK9h of Al–Si–Mg system reinforced with silicon carbide particles on thermophysical characteristics: thermal conductivity, TCLR and density. Performance studies were carried out on samples of the MCM system Al–SiC with a volume content of reinforcing particles of silicon carbide 69±1 vol.%. The volume percentage of reinforcing particles was calculated by weight percent based on the MCM density. Silicon carbide powder of grade F220 with particle size of 63–50 mcm was used as reinforcing particles. MCM was manufactured by powder metallurgy using the hot pressing technology of aluminum and silicon carbide powders. One of the disadvantages of the powder metallurgy method is the porosity of the material, which negatively affects not only the mechanical characteristics of the material, but also the thermophysical ones. An increase in the density of the material can be achieved both by determining optimal process parameters of the MCM production process and by applying subsequent heat treatment. Therefore, the resulting MCM was vacuum annealed at various temperatures. After that thermophysical characteristics of MCM in temperature range from 20 to 400 °C were examined. The determination of thermal conductivity was carried out by a calculation method taking into account experimentally measured values of specific heat capacity and temperature conductivity according to the «laser flash» method. Measurement of TCLR is carried out using a method of determining the change in the length of a solid sample during thermal expansion relative to parts (support and pusher) made of quartz glass or aluminum oxide. The hydrostatic weighing method is used to determine the density of the material.

It is shown that an increase in the vacuum annealing temperature lea

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8.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-68-75
УДК 669.018.95
Zhabin A.N., Nyafkin A.N., Serpova V.M., Krasnov E.I.
METHODS OF PHYSICAL VAPOR DEPOSITION FOR THE MANUFACTURE OF METAL MATRIX COMPOSITES (review)

The article discusses the features of physical vapor deposition methods for the manufacture of metal composite materials based on the results of a review of foreign scientific and technical literature.

Recently, to obtain MCMs based on titanium and intermetallic matrices, reinforced with high-strength ceramic fibers of silicon carbide, physical vapor deposition technologies are used, which are an intermediate stage in the technological process of manufacturing monolithic MCMs. The most common methods of this technology used to obtain MCMs include electron beam deposition and magnetron sputtering.

The use of such methods makes it possible to obtain a uniform layer of matrix material on silicon carbide fibers.

One of the important distinctive feature of the methods is that for the deposition of the matrix material on silicon carbide fibers by the method of electron beam deposition, higher evaporation temperatures are required in comparison with the method of magnetron sputtering.

It is noted that when using the magnetron sputtering method, the chemical composition of the deposited matrix layer corresponds to the chemical composition of the cathode material. When applying the method of electron-beam deposition, a reduced concentration of low-melting elements is observed in comparison with the chemical compositions of the sputtered cathode.

The main advantage of these methods is to achieve a uniform distribution of fibers without contact with each other in the volume of the CM. In addition, the fiber volume fraction in the MCM is controlled by the coating thickness. However, magnetron sputtering deposited coatings provide additional versatility in the sense that they are suitable for in-situ deposition of interfacial coatings on fibers prior to matrix alloy

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9.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-76-92
УДК 678.84
Shestakov A.M.
CERAMICS BASED ON ORGANOSILICON POLYMERS-PRECURSORS: METHODS OF PREPARATION AND PROPERTIES (review)

An oxide-free ceramic based on silicon compounds such as silicon carbide (SiC), silicon oxycarbide (SiCO), silicon nitride (Si3N4) and their derivatives (SiCN, SiAlON, etc.) is widely used, including in aviation and space technologies, due to its high temperature resistance, chemical resistance, excellent mechanical and electrical properties.

Over the past 50 years, organosilicon polymers have been used to produce advanced ceramics. Ceramics based on such polymers-precursors exhibit enhanced of thermal and mechanical properties with respect to creep, oxidation, crystallization, and phase separation up to 1500 °C and higher.

This review considers the main types of preceramic organosilicon polymers, methods of their synthesis and physical, and chemical properties. The dependence of the composition and properties of ceramics is shown, as well as the wide possibilities of their regulation by selecting the required of polymer precursor.

The polymer nature of organosilicon precursors makes it possible to apply to them the entire range of shaping methods used in polymer processing technology, which simplifies the technology for producing ceramic products of complex geometric shapes. The composition and structure of ceramics is determined by the technological parameters of the precursor processing.

The use of modifying fillers of various natures in preceramic compositions makes it possible to control the macro- and microstructure of ceramics, its mechanical and physical properties.

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10.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-93-101
УДК 678.747.2
Dyshenko V.S., Minibaev M.I., Usacheva M.N.
CREATING HOLES IN SOUND-ABSORBING STRUCTURES DURING MOLDING

Reducing noise pollution is an important task in the modern world. In aircraft manufacturing, safety takes the first place in production, followed by the task of reducing noise levels. Sound-absorbing structures can be used to reduce the noise from the engine and nacelle of the aircraft. In this work, the task was to obtain perforated holes in sound-absorbing panels during molding and to examine prepared samples in tension.

Monolithic CFRP slabs based on a twill weave fabric were chosen as the objects of research: with subsequent perforation, performed on a CNC milling machine, followed by perforation, performed on special equipment and without perforation. For the manufacture of monolithic CFRP slabs, a blank package was assembled. Plates were made by the infusion method.

For the manufacture of perforated CFRP plates, a special tooling was made, consisting of a polyvinyl chloride base with cylindrical holes, into which cylindrical pins are inserted.

Structurally similar specimens were cut from the slabs at an angle of 4–5°, the orientation of the holes was the same as in real sound-absorbing panels.

All samples were tested for tensile strength. Specimens cut from slabs, perforated by plate molding, when stretched give a result 25% higher than specimens, the perforation of which was obtained by CNC machining.

This is due to the fact that when perforation is performed on a milling machine, damage to carbon fibers and «nucleation» of stress concentrators in the samples occurs, which entails a decrease in the strength of CFRP samples. When perforating CFRP specimens during molding, the carbon fibers are bent, which also leads to a decrease in strength compared to the initial values.

This method of&

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11.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-102-112
УДК 66.017
Kuzin Ya.S., Kozlov I.A., Sibileva S.V., Fomina M.A.
INVESTIGATION OF THE INFLUENCE OF COMPONENT COMPOSITION OF PEO ELECTROLYTES ON THEIR STABILITY AND COATING PROPERTIES

There are extremely many publications on PEO in open sources, but the practical issues of mastering PEO by the industry are not affected. Very little is known about the safety of electrolytes over time, which is the key to the economic efficiency of the technology.

Based on the above, the study of the component composition of PEO electrolytes on their stability and coating properties is an urgent task, and the results obtained will expand the implementation of plasma electrolytic oxidation technology in the industry.

In this work the efficiency of various variants of the component composition of alkaline electrolytes of plasma electrolytic oxidation was studied. Technical liquid glass, NaOH, Na2B4O7, Na3PO4, and NaAlO2 were used as components of aqueous solutions. All of the studied components of electrolytes are the most common for use in PEO processes of aluminum alloys. The influence of the component composition of electrolytes on their stability during 30 days of exposure was evaluated, and the most stable compositions were selected. The structure and properties of coatings formed on samples of aluminum alloy AK6 during plasma electrolytic oxidation (PEO) are studied. The dependences of the hardness of coatings and their growth rate on the composition of the electrolyte are established. Possible variants of coating growth in the PEO process with different component composition of electrolytes are proposed.

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12.
dx.doi.org/ 10.18577/2307-6046-2020-0-11-113-121
УДК 66.017
Dobrynin D.A., Iatsyuk I.V., Doronin O.N.
REMOVAL OF HARDENING COATINGS BASED ON TITANIUM NITRIDE AND ZIRCONIUM NITRIDE FROM THE SURFACE OF PARTS MADE OF TITANIUM ALLOYS

The actual problem of modern aircraft construction is post-operational repair of GTE parts, in particular, the repair of compressor blades. Comprehensive repair of GTE compressor blades includes the operations of removing the used coating, preparing the surface of the blades for re-coating, and the coating process according to the enterprise's serial technology. The paper provides an overview of the most common chemical and electrochemical methods for removing hardening coatings based on titanium nitride and zirconium nitride from the surface of compressor blades and other parts made of various materials. The main disadvantages of chemical methods are: aggressiveness and toxicity of the components of solutions, the complexity of preparation and adjusting the composition of solutions, the duration and multistage process. The main disadvantages of electrochemical methods are the multistage and high labor intensity of the process, as well as the high cost and energy intensity of the equipment used. Taking into account the analysis of the disadvantages of the considered methods of chemical and electrochemical removal of hardening coatings based on titanium nitride and zirconium nitride, FSUE "VIAM" has developed methods for chemical removal of hardening coatings based on titanium nitride and zirconium nitride from the surface of parts made of titanium alloys, as well as compositions of solutions based on acids (acidic) and on based on salts of inorganic acids (unkilized) and processing modes that allow the removal of the coating with the least effect on the base material. According to the research results, it was found that the removal time of hardening coatings based on titanium nitride and zirconium nitride in an acid solution is 3.5 and 5.5 times, respectively, more time to remove the same coatings in an acid-free solution. Recommendations are given on the duration of the coating removal process in an acid solution and to determine the

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