This article analyzes the chemical composition, structure, and mechanical properties of heat resistant nickel alloy, grade EP648, fabricated by various methods: deformation, lost wax casting, and selective laser sintering. It has been demonstrated that the deformed material is characterized by low porosity and higher impact toughness and plasticity; the cast material is characterized by coarser grains and a high level of long term strength and low cycle fatigue; and the material fabricated by selective laser sintering is characterized by a higher content of oxygen and nitrogen and a fine-grained structure with extremely intense grain irregularity and inheritance, as well as higher short term strength.

Work was carried out to evaluate the effectiveness of the identification of operational defects during capillary testing of parts of aircraft from heat-resistant alloys using flaw detection fluids of domestic and foreign production, revealing defects with an opening size of 1 μm or less. Two complementary approaches to a qualitative assessment of the effectiveness of various sets of flaw detection materials recommended for use in conducting capillary control in the production and operation of parts of aircraft equipment are considered with the aim of choosing a kit that identifies defects of a certain type with the smallest dimensions. The first approach is based on the assessment of the main defectoscopic properties of penetrating multicomponent liquids, which ensure their penetration into the cavities of surface defects, and the second is based on the experimental determination of defect detection parameters with a probability of 50 and 90 % with a confidence probability of 50 % and with a probability of 90 % with a confidence probability of 95 %.

The aim of this paper is to determine uncontrolled zones in the main parts of aircraft engines during capillary control using a luminescent set of flaw detection materials LYuM1-OV. The main factors affecting the defect detection process have been described. The approach not previously used in the practice of aviation enterprises has been experimentally tested. This approach takes into account the quality of applying a film-forming developer to various surfaces of structural elements of aircraft parts, using luminescence brightness samples. The research has clearly shown the control zones of holes of different diameters and herringbone type locks of different widths. It is established that the data presented in literature sources of technical and technological documentation on the controllability of holes and herringbone type locks differs from the experimental data.

Thermodilatometric methods of analysis are used to study the structural parameters of polymer materials, however, when studying moisture-saturated compositions certain difficulties arise in their identification. The results of thermophysical tests of VKU-25 carbon fiber samples in the initial state and after moisture saturation are presented. It is shown that heat treatment of materials affects the recorded values of the glass transition temperature of the epoxy matrix. When the samples are exposed in water or above the water surface, the sorbate penetrates into the polymer at the same rate, which is confirmed by almost identical values of water absorption at the same exposure time. The estimates of the thermal coefficient of linear expansion (TCLE) of the samples in the range of 20 - 250°C are given. Moreover, it is shown that the glass transition temperature of the plasticized polymer matrix depends on the direction of fiber reinforcement. In the case of moisture-saturated carbon fiber (CF)heated to 210°C, the formation of main cracks occurs mainly at the fiber-matrix interface. The glass transition temperature (GTT) of the material in the dry state (176 - 177°C), appeared almost independent on the heating rate, whereas for water-saturated samples, GTT changes significantly and can be described by a polynomial of the 2nd order. After exposure of the carbon fiber under conditions of high temperature and humidity, two relaxation transitions corresponding to the systems occur in the polymer matrix: epoxidian oligomer— amine hardener and polyfunctional resin— amine hardener. The glass transition temperature is 132 and 159°C in the first and in the second, respectively. The results obtained can be used in the development of new polymer composite materials.

The paper shows the features of the formation of the structural-phase and textural state of the EP648 alloy obtained by the SLM method in the initial state, after hot isostatic pressing and heat treatment. It was found that in the process of synthesis, a limited crystallographic texture of the γ-phase is formed, which does not undergo significant changes in the process of subsequent treatments. The uniform distribution of fine particles of the hardening phases, apparently, leads to an increase in both the strength and plastic properties of the material obtained by the SLM method in comparison with the material obtained by the traditional technology.

The review article is devoted to high-temperature borosilicate molybdenum alloys reinforced with titanium carbides MoSiBTiC. The article discusses phase diagrams, microstructure, production methods, mechanical properties, resistance to oxidation of these alloys, and protective coatings. It is shown that the long-term strength of MoSiBTiC alloys is superior at high temperatures to nickel heat-resistant alloys (NHRA) of the latest generations. Borosilicate molybdenum alloys MoSiBTiC can replace nickel heat-resistant alloys in many engineering fields, including in the production of cast parts for the hot section of aircraft gas turbine engines.

Research has been carried out to assess the defectoscopic properties of various compositions of powder preparations in order to determine whether they can be used as part of a modern Russian set of defectoscopic materials for luminescent penetrant testing that ensures detection of discontinuities with sensitivity class 1 as per GOST (State Standard) 18442. To improve the efficiency and reliability of flaw detection in hard-to-reach places of complex shaped parts, compositions have been selected that increase the brightness, contrast, and stability of the indication pattern to mechanical action due to high rates of adsorptive and adhesive interactions of the used penetrant fluid and the surface of the tested part.

The paper studies chemical composition, structure and mechanical properties of the heat-resistant nickel EP648 alloy obtained by deformation, die project casting and selective laser melting. It is shown that the deformed material is characterized by low porosity, high impact strength and ductility, the cast material has large grains, high long-term strength and low-cycle fatigue. The material obtained by selective laser melting is characterized by an increased content of oxygen and nitrogen, fine-grain structure with large variation in grain size strongly expressed and heredity, and also high short-term strength.

In this work, temperature fields have been modeled during autoclave molding of VKU-46 carbon-fiber-reinforced plastic. It has been shown that a degree of conversion of 97.2–98.4% is achieved in the center of plate upon curing according to the chosen temperature–time mode, while the material is cured completely near the ends. In this case, the glass transition temperature of the material is in the range of 193.2–205.7°C upon preliminary heating. On the contrary, it decreases to 182.5–197.6°C at repeated heating due to the conformational change of macromolecules.

На правах рукописи ШАЙСУЛТАНОВ Дмитрий Георгиевич СТРУКТУРА И МЕХАНИЧЕСКИЕ СВОЙСТВА ВЫСОКОЭНТРОПИЙНЫХ СПЛАВОВ СИСТЕМЫ CoCrFeNiХ (Х=Mn, V, Mn и V, Al и Cu) 05.16.01 -Металловедение и термическая обработка металлов и сплавов АВТОРЕФЕРАТ диссертации на соискание ученой степени кандидата технических наук Екатеринбург ̶ 2015 Работа выполнена в ФГАОУ

The microstructure of a 1417M alloy after magnetohydrodynamic (MHD) treatment has been studied. An electric field induced in the aluminum alloy melt is shown to cause electric transfer and to homogenize its structure. During the formation of an ingot upon MHD treatment, intermetallic phase dendrites are preferably oriented along the lines of the induced electric field.

The X-ray nondestructive testing process is carried out by a system which includes an object of control (OC), source of radiation, detector, and operator. Under interaction of radiation with the OC, its radiation image is formed as an X-ray dose distribution in accordance with the OC properties. At this stage, useful information about the OC is formed, which is further partially lost, partially distorted, and veiled with a noise by conversion of a radiation image into an optical one. The optical image is analyzed by an operator, and the result of testing depends on his physical and emotional state. In this article, the step-by-step analysis of the entire radiation monitoring system is performed. The first stage is formation of a radiation image. For the theoretical estimate of the minimum defect size detected by the X-ray testing system, spatial-frequency spectrum analysis was used. The minimum sizes of a defect were established, for which the radiation image will be formed depending on the characteristics of the source of radiation and the OC. The second stage is the transformation of the radiation image into an optical one. We presented the simulation of this process and developed a model of how an operator recognizes the X-ray optical image and makes the decision about the OC condition. The optical image formation was studied and the choice criterion for the radiation energy was determined by using the digital radiography technique.

The process of casting carbonless VZhM4 nickel superalloy cooled blades with a single-crystal 〈001〉 structure on UVNK plants is developed. Model blade units with seed parts for the formation of a single-crystal structure in a turbine blade are designed, the structure of the alloy is studied, and experimental batches of single-crystal blade ingots are cast. The influence of the directional solidification conditions on the structure of the carbonless alloy and the susceptibility of the single-crystal structure of the ingots to defect formation are investigated.

The damping capacity of a VT6 titanium alloy sample is shown to depend on the thickness of a new designed Al–Ni–Y alloy coating during vibrodynamic tests at the first flexural mode resonance frequency. The coating 20–100 μm thick is found to decrease the vibrostresses in the weakest section of the sample by 9–31% at a temperature of 20°C and by 40.6% at a temperature of 400°C and a coating thickness of 60 μm. The dependences of the damping capacity of the alloy–coating composition on high-temperature holding of coated samples in an atmospheric furnace ( t = 400°C, τ = 500 h), the salt fog chamber conditions ( t = 35°C, τ = 3 months), and the action of an abrasive flux (quartz sand, average particle fraction of 400 μm, particle velocity of 100 m/s) are studied.