№2 2015
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1
The article describes experience on application of semiproducts made of high-modulus Al–Be–Mg alloys (ABM) in experimental structures. An experimental work on production of the wing spoiler skin from ABM1 alloy for An-72 aircraft was carried out under scientific supervision of Academician I.N. Friedlander and Doctor of Science (Tech.) K.P. Yatsenko at Voskresensk experimental and technological center of VIAM in cooperation with Antonov Design Bureau. A fuselage section from ABM1 alloy was produced together with A.S. Yakovlev Design Bureau. TSNIIMV (now JSC «Composite») produced ABM1 alloy pipe weldments which are used by S.A. Lavochkin Design Bureau for production of solar battery modules of «Venera» spacecraft (from 5 to 16) and «Vega» series.
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2
Structure and properties of pieces produced by selective laser sintering of powders of high-chromium heat-resistant alloy EP648 by Concept Laser unit were investigated. It was shown that the developed sintering conditions provide production of dense parts with average volume porosity as much as 0.07% and a high complex of mechanical properties equal (or higher) to maximum certified values for cast material.
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3
Modern principles and approaches to development of processing procedures for manu-facture of wrought billets of disks and blades from heat-resistant nickel, titanium and other alloys for the purpose to achieve an optimum combination of operational and processing characteristics were described in the paper. Isothermal forging of disks in a special oxida-tion-resistant stamping tool without the use of a vacuum camera was considered.
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4
VKS-180-ID steel is recommended for production of high-loaded parts, landing gears, airframe and engine. Metallurgical characteristics of high-strength maraging steel VKS-180-ID melt in a vacuum induction furnace (VI) with the subsequent remelting in a vacuum arc furnace (VA) using the chosen system of REM-based micro-alloying and addition of nickel oxide were studied. The technology allows production of steels with a low content of gases and impurities (carbon ≤0.005%; oxygen ≤0.004%; nitrogen ≤0.003%) providing a high level of mechanical properties both in longitudinal and in transverse directions (tensile strength, impact strength, ductility).
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5
An impact of a negative electrical potential (voltage) of the substrate on deposition rate of multicomponent Ni-based coatings produced by the cathodic arc physical vacuum deposition from the surface of cathodes made of nickel-based alloys with additives of chromium, aluminum, tantalum, rhenium, yttrium, hafnium on the surface of specimens of various cast heat-resistant nickel alloys was investigated. It was shown that the maximum etching rate could be achieved in case of applying of 350 V potential to a substrate. The threshold values of spray voltage for all compositions of heat-resistant materials tested in this study were determined. An influence of the chemical composition of the plasma formed in vacuum from the cathode surface on the sputtering threshold was stated depending on the content of chromium and high-melting point elements in the cathode.
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6
A possibility of photometric determination of cobalt content in titanium-based alloys within the concentration range of 6–12% mass. was studied. Ethylene diamine (EDA) was used as reactant. The studies were focused on factors of stability in time and selectivity of the reaction of Co with EDA and its influence on light absorption of EDA in combination with some elements contained in the alloys, which form colored EDA (Ni, Cu, Cr) or colorless (Zn, Mo, V, Sn) soluble complexes. It was established that the color of a complex with EDA was stable within several hours. Reaction sensitivity is 0.1 microgram of Co in 1 milliliter of solution. The light absorption of cobalt has its maximum at λ=360 nm. In order to prevent precipitation of titanium, potassium pyrophosphate was applied, since it forms with titanium soluble complexes, which do not affect changes in optical density of Co+EDA complex. This work resulted in the development of a technique for a direct photometric determination of hig
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7
An influence of climatic factors and working fluids on properties of CFRP VKU-35 manufactured by RTM technology was studied. It was shown that CFRP VKU-35 has a high stability of properties under an influence of environmental factors (at least 75% of the initial value) and in this respect is not worse than the typical structural CFRP KMU-11tr manufactured by autoclave molding.
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8
The research was focused on modification of the polyimide binding material SP-97s. The character of transformations in the binder, which contents modifying additives of different types, was studied on the stage of material forming. The optimum amount of modifiers was determined and effectiveness of each of them with the purpose to decrease curing temperature of binder down to 170°C was estimated taking into account the properties of fiberglass plastics. The composition of modifying binder was established, polyimide fiberglass plastic STP-97K was developed and its properties were studied. It was demonstrated that lowering of the curing temperature does not cause a significant change of properties of the material in different operational conditions.
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9
Currently, the use of natural fibers in production of up-to-date polymer composite materials (PCM) becomes much more important. Replacement of conventional glass and carbon fillers with natural ones reduces both production cost and the effect of polymer composite materials production on the environment. Furthermore, application of natural fibers for manufacturing of polymer composite materials boosts development of agricultural industries traditional for Russia.
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10
Causes of porosity formation in the products made of polymer composite materials prepared by the autoclave and out-of-autoclave methods are discussed in the paper and recommendations for porosity reduction are given.
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11
Possibility of production of continuous cords from short oxide fibers by direct formation of aqueous pulp was investigated. The laboratory unit for production of cords equipped with forming assembly, heat chamber and winding assembly was designed and installed. The experiment showed the possibility in principle to produce cords from short oxide fibers.
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12
A methodology has been developed to define parameters of the topological structure of the polymer network in cross-linked polyethylene by the stress relaxation method. The obtained experimental data were used to calculate parameters of the polymer network of cross-linked polyethylene. Parameters of the topological structure of peroxide cross-linked polyethylene obtained by stress relaxation and equilibrium swelling methods were compared.
