№12 2015
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1
The investigations of directional solidification parameters (rate and temperature gradient of crystallization) on microstructure, structural and phase parameters (lattices parameters of γꞌ- and γ-phases, misfit) and mechanical properties of intermetallic VIN alloys based on nickel were considered.
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2
The harmful influence of sulfur and phosphorus on heat resistant properties of ZhS36-VI alloy during stress rupture test on long base testing (500 and more hours) as well as on middle quantity of cycles to rupture upon MCF wasdetermined . The possibility to reduce the content of harmful influence of sulfur and phosphorus impurities or their neutralization through microalloing by lanthanum that positively influence on alloy properties recovery was investigated. The mechanism of lanthanum addition for neutralization of these impurities harmful influence was suggested whereby sulfur removes from the melt as refractory lanthanum sulfides by their adhesion on crucible walls during melting and on foam filter during casting. In contrast to sulfur the refractory phosphides with lanthanum don’t remove from the melt. The properties comparison of single crystal alloy cast on units of low- and high gradient direct solidification UVNK-9A and UVNS-5 is presented.
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3
The results of researches of single-crystal rotor blades from cast Ni-based superalloy ZhS32-VI in process of long-time life cycle testing of gas turbine engine (high-pressure turbine) are represented for microstructure and substructure. It is shown that precipitation of TCP-phases particles in the alloy during high-temperature testing is accompanied by the decreasing of crystal lattice constant of γ-solid solution. It is verified by data of x-ray diffraction analysis, x-Ray microanalysis and scanning electron microscopy. The point is proposed that decreasing of alloying element content in the γ-solid solution as result of TCP-phases precipitation (rich with the refractory elements) leads to the fall of the high-temperature resistance of the material. Also, a TCP-phases make negative influence on mechanical properties of the alloy due to the local destruction of coherency for interphase boundaries in zone of development of TCP-phases particles.
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4
The LCF behavior for Ni-base superalloy VZh175 was investigated for a given total strain, ratio R=0 and stain amplitude εa=0,4–0,6% at test temperatures 20 and 650°С. Parameters of elastic-plastic strain were observed in this article.
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5
Comparative research of sulfide-oxide corrosion resistance of ZhS36 nickel superalloy with different advanced protective ion-plasma coatings is conducted. Results of accelerated comparative research method («salt shell method») tests of ZhS36 nickel superalloy with advanced protective ion-plasma coatings in comparison with standard SDP-6 coating in temperature range 850–900°С are presented.
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6
The article presents a research on development of methods to assess the geometric characteristics and volume fraction of porosity, the geometric characteristics and volume fraction of eutectic (γ-γ)ʹ-phase, and the geometric characteristics of particles of the hardening γʹ-phase in monocrystalline Ni superalloys ZhS32U-VI. The results of investigations on proposed methods of quantitative metallographic analysis of blanks from the ZhS32U-VI superalloy, derived by directional solidification from the melt in different temperature gradient are presented.
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7Silicium determination in nickel alloys by ICP-AES method in combination with micro-wave preparation
In various types of nickel alloys silicon is present in a wide concentration range from a few hundredths of a percent in the heat resisting nickel alloys to whole percent in the nickel-based solders. The paper describes a method of measuring the mass fraction of silicon in the nickel-based alloys by atomic emission spectrometry with inductively coupled plasma (ICP-AES) in combination with microwave sample preparation. Compositions of dissolution mixtures and parameters of microwave digestion were selected. Limits of relative measurement error for Si content from 0,01 to 8% don't exceed 2% (±δ, at P=0,95).
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8
The article presents research results on technological parameters of deformation, structure and phase composition of a pilot intermetallic ortho alloy Ti–13Al–40Nb–5(Zr+V+Mo+W)–0,5(Si+C) determination. It has been resolved that no strain strengthening effect throughout hot working process is observed at a temperature of 1000°С. Temperature intervals of the following phase areas have been determined for the pilot alloy: (О+βA2)→(О+β(A2+В2)+α2)→(β(A2+В2)+α2)→β(A2+В2). Also it has been shown that technological plasticity (degree of strain) decrease at deformation temperatures lower than 1000°С and prolonged duration is caused by phase transformations: in these conditions decomposition of β-phase takes place together with the ordered intermetallic O- and α2-phases precipitation.
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9
The article contains the review and analysis of methods of increasing in fire safety of fibrous thermal insulation. Permanent growing requirements to service properties of heat-insulating materials are caused by the progress in such areas of the industry, as transport, aviation, energy, chemical, oil-extracting and others, and also need of providing operation safety of machines and mechanisms. A number of new heat-insulating systems is developed for implementation of fire safety requirements of new aviation rules. New types of protective coatings meeting the modern requirements of aviation rules are developed.
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10
The epoxy polymer based on Ethal-247 resin and cycloaliphatic Ethal-45M curing agent was exposed to Gelendzhik and Saransk atmosphere. The color characteristics of the specimens were measured and it was shown that colorimetric property such as a color difference of the polymer surface is sensitive to initial stages of weathering. It was shown that the natural UV-radiation is a dominant factor for polymer degradation. The application of solar radiation doze provides more reliable results.
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12
The article describes the experience of several countries (Japan, USA, UK, Germany and others.) to reduce the negative impact on the environment and meet the legal requirements by manufacturing products of national economic destination of the recycled carbon fiber reinforced plastics, fiberglass reinforced plastics and fiber reinforced polypropylene. Some of the main technological processes using abroad in the manufacture of products from recycled polymers composite materials are described. At present, the solution of recycling problem is one of the aspects contributing to widespread adoption and application of polymeric composite materials in priority industries. This is due to the fact that today more and more consumers prefer those materials and products the negative influence of which on the environment in the process of manufacture, use and disposal would be minimal.
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11Part 1. Research of the influence of sorbate moisture on epoxy matrix and layered car-bon fiber on its basis
Processes of sorption and desorption of moisture by epoxy polymeric matrix and layered carbon fiber on its basis are considered. Moisture diffusion factors are estimated on stages of sorption and desorption. The conclusion is drawn on nature of diffusion in epoxy matrix and in polymeric composite material, on the basis of this matrix. The qualitative analysis of epoxy matrix, in the course of moisture sorption, is carried out by FTIR Spectroscopy. The structure and energy of molecule of epoxy matrix is calculated, at absence and presence of the bonded moisture in its composition. Researches of mechanical properties of polymeric composite materials are conducted at different values of moisture content. Changes of thermophysical properties of layered carbon fiber in the course of moisture sorption and desorption are investigated.
