In this work, an attempt was made to obtain a dispersion-reinforced composite material based on molybdenum using the method of spark plasma sintering. To prepare the powder mixture used a ball mill. The density of the alloy after sintering at a temperature of 1450 °C was ≈96.11% of theoretical. The mechanical properties of the alloy were σ_f,m=400 MPa, KS=8.84 kJ / м², average microhardness – 233.5 HV 0.1. In the study of the microstructure, the presence of titanium and zirconium oxides and a uniform distribution of carbon over the volume of the alloy were found, but carbides in the material structure were not observed. After quenching in the structure, the alloying elements were dissolved in the molybdenum matrix, and molybdenum carbide was precipitated. In this case, the strength increased to σ_f,m=590 MPa, and the microhardness decreased slightly. The aging of the alloy led to a slight increase in the microhardness of the alloy and the precipitation of molybdenum carbides and complex carbides of non-stoichiometric composition.

Along with the many advantages of epoxy polymers and, often, unique properties, they also have disadvantages. The most significant drawback of polymer composite materials based on epoxy binders is that they are easily susceptible to burning. Therefore, the use of flame retardants is a very effective method to prevent or reduce the intensity of the combustion process of epoxy polymers. Flame retardants are special additives that increase the resistance of various materials to combustion, acting by slowing down combustion and making it difficult to ignite the material. Among flame retardants for epoxy resins, reactive type additives are of particular interest, since they, unlike traditional heterogeneous additives (most often mineral fillers), do not create technological difficulties, and they do not significantly reduce the physical and mechanical characteristics of the initial composition. In the first part of the work, the combustion mechanism of polymeric materials and the main ways to increase the resistance to burning of polymers are considered. Traditional and new classes of reactive flame retardants based on halogenated and organophosphorus compounds are presented.

The second part of the work considers a wide range of various additives based on functionalized organophosphazenes, which have found application as flame retardantsfor epoxy resins, as well as compounds on the basis of nitrogen-containing organic compounds, which, when burned, emit a large amount of neutral, non-toxic gases. Also, there is presented a review of reactive type flame retardants based on silanes, siloxanes and silsesquioxanes. These compounds have great thermal stability, due to which they significantly reduce the amount of heat released during combustion and contribute to a decrease in combustibility. In addition, new epoxies based on modified thermostable, inflexible organic structures such as biphenyls or naphthalen

In the production of promising aircraft and a number of other types of equipment, the fight for reduction of mass-dimensional characteristics of parts without reduction of their strength becomes of particular importance. The use of PCM based on thermoplastic heat-resistant matrices such as polyethyrimide, polysulfone or polyether ketone can solve this problem in a large part of the cases.

Thermoplastic PCMs have almost unlimited storage life of prepregs, their production is environmentally safe, they show high impact resistance, matrix structure is weakly dependent on forming conditions, and their repair and recycling can be carried out much more easily than reactor-based PCMs.

The article is devoted to the development of polymer composite materials based on carbon fabrics of sarge weaving and polyester ether ketones.

For the manufacture of carbon plastics in the work used polyester ether ketones produced by England and China brands Victorx 90Р, and Zypek 550PF and 330UPF, film TK Lite manufactured by Austria.

Two technologies for obtaining TPKM have been tested - film and prepreg. It has been found that low fluidity polyether ketones are not desirable for the manufacture of carbon plastics because they do not provide for proper impregnation of the fiber with melt.

In order to assess the potential of obtained sheet carbon plastics as structural materials, studies were carried out on the defect of their structure and determination of strength characteristics of samples from normal and defective areas. It has been found that the dimensions of the fully and partially shaped areas of the sheet correlate with the dimensions of the press plates and the proportion of quality carbon plastic increases with the dimensions of the forming area. It is shown that the

Modern production engineering of repair of an aeronautics develops constantly and improved, therefore there are all new necessities for creation or development of already available bonding materials and the production engineering used at operative repair of aviation designs in the conditions of the maintaining organisations. Therefore in the given work features of production engineering of installation of time layered stoppers from an aluminium foil with a sticky layer (FSL) for time operative repair of an aeronautics in the conditions of aerodrome were observed. The carried out analysis of a condition of this point in question allowed to choose components for manufacturing of samples FSL, to complete production engineering of drawing of a glutinous layer on an aluminium foil which would secure conservation of its adhesive and technological properties not less, than 12 months from the date of manufacturing.

In the capacity of criterion sizing up a way of preparation of surfaces of the sample of a sheeting and the joint magnitude of adhesion of a glutinous layer to a surface of a repaired element is chosen. Researches showed that adhesion depends on force of clip FSL to a surface of an aluminium alloy and from a condition of the given surface, the greatest adhesion possesses FSL to a surface with an anodic covering.

For studying of agency pasted FSL on level of acoustical loadings on aluminium sheetings tests on measurement of level of a sound pressure and a noise sorbtion which showed decrease in level of a sound pressure in all range of geometrical frequencies were conducted. Accomplishments of the given work of research FSL besides conducted in a course showed, the stopper from three layers FSL considerably reduce growth rate of a fatigue crack in aluminium sheetings.

Thus, the spent comprehensive investigations of properti

Properties, processing techniques and possible applications in «hot sections» of gas turbine engine of different structural high-temperature materials with an operating temperature higher than 1200 °С are highlighted. Composites with a multi-layered structure based on «ceramic/carbon», «ceramic/ceramic», «ceramic/metal» systems have demonstrated to be promising materials. Layer widths with low/high Young modules, their ratio and arrangement have a significant impact on the strength parameters. High-temperature composites with a multi-layered structure can have a «graceful failure» mode and higher toughness as compared to particle reinforced ceramic composites.

The surface structure of reactive coatings based on a composition of refractory glasses of the BaO–Al₂O₃–SiO₂₂ system and silicon tetraboride was studied using atomic force microscopy and scanning electron microscopy, depending on the conditions of heat treatment of coatings. The correlation of AFM and SEM results of the studied compositions of reactive coatings was revealed. Due to the transition to a visco-fluid state at the firing temperature with an increase in the firing duration, the surface roughness is reduced and does not depend on the initial relief of the protected substrate. A slight roughness of the coatings was revealed, the level of which is reduced as a result of firing in an oxidizing environment. The surface roughness of coatings is determined not only by the duration of formation at firing temperatures, but also by the phase composition of the coating compositions under study. The relief of the surface causes the presence of non-oxidized silicon tetraboride particles in the coatings, as well as a high-temperature modifying glass of the BaO–Al₂O₃–2SiO₂ composition, which crystallizes under high-temperature exposure to form barium silicates. A key structural feature of reactive coatings is the preservation of under-oxidized silicon tetraboride particles in the glass matrix volume, which determines the high level of properties of reactive coatings. The dynamics shows the effectiveness of the selected modes of high-temperature firing of coatings, which results in obtaining a composite structure that is formed step by step. Each structural element in the composition of reactive coatings affects the firing temperature of the coatings and their temperature stability. During the operation of coatings, it is possible not only to preserve the Si–B covalent bond, but also to form new bonds between silicon tetraboride, bor

This article presents investigations of the properties of ion-plasma wear-resistant coatings based on multicomponent titanium nitrides of the type (Ti–Al) N, (Ti–Zr) N, (Ti–Al-Mo) N deposited on the MAP-3 installation on structural steels EP517Sh, EP678, VKS- 170 in comparison with monocomponent TiN. The wear resistance and heat resistance of the applied coatings were studied at temperatures of 400 and 600 ° C. According to the results of wear resistance tests, it was found that a temperature of about 400 ° C is working for monocomponent titanium nitride, at this temperature multicomponent compositions do not have any advantage. When the test temperature rises to 600 °C, we see that individual multicomponent wear-resistant coatings (Ti–Al–Mo) N, (Ti–Zr) N have an advantage in wear resistance over simple TiN. Meanwhile, it was found that the (Ti–Zr) N coating has low heat resistance, due to the fact that the ZrN constituent in it is actively oxidized at temperatures above 450 °C. X-ray diffraction studies of coatings (Ti–Al–Mo) N, (Ti-Al) N showed the presence of the main phase TiN. In general, alloying titanium nitride with aluminum increases its wear resistance and heat resistance to temperatures of the order of 600 ° C; however, this only works if aluminum is present directly in the TiN solid solution at a concentration in the initial cathode of 6–7%. It was also established that the layered structure of a wear-resistant TiN–Ti–TiN coating based on titanium nitrides is more heat-resistant compared to a monolayer one, since the presence of a denser metal layer of titanium creates a barrier to oxygen. Analysis of the test results showed that the maximum temperature range for the use of multicomponent nitrides on structural steels as a wear-resistant coating is not more than 600–650 °C.

Coating type

Academician I.N. Friedlander in his works outlined the prospect of using welded aluminium-lithium alloys instead of those traditionally used in the aircraft design in order to increase its weight efficiency, service life and reliability. However, conventional electrochemical processing techniques do not always allow these alloys to produce high quality, stable coatings.

The work carried out studies of plasma electrolytic coating formed using silicate-phosphate electrolyte on samples of sheet semi-finished product from aluminium-lithium alloy of 1441Т1. Studies were conducted to change the rate of growth of the coating over the oxidation time. Analysis of change of microhardness of coating and its electric resistance was also carried out.

Directly proportional dependence of the general thickness of the covering formed on samples from aluminum - a lithium alloy 1441Т1, from duration of plasma electrolytic oxidation for 165 minutes is established. It is thus established that the mechanism of growth of an oxide coating at an initial and final stage differs.

Results of research of microhardness of a covering on various time intervals of plasma electrolytic oxidation allowed to confirm assumptions of direct link of this indicator with chemical composition of an oxide coating. The maximum value of microhardness is reached by 120th minute and remains almost invariable at continuation of process of drawing, as well as mass % of the content of aluminum in a covering.

It has been found that reduction of volume defects in PEO coating over time of oxidation directly affects dielectric properties of samples surface. Breakdown resistance is almost directly proportional to the thickness of the coating formed, but after reaching 50 μm, there is a significant decrease in the rate of growth of the index.&

In the field of development of new paint and varnish materials the problem of replacement of chromate pigments with less toxic components, not conceding to them on anticorrosive properties is at present especially actual.

For ensuring anticorrosive protection of fixing connections, and also contact couples of combined designs of VIAM protective polymeric pastes VP-1 and VZP-1 have been developed. However these pastes contain toxic compounds of chrome in the structure.

For modifying of protective polymeric pastes the fillers, potentially capable to improve protective and other operational properties of coverings have been picked up at the general decrease in the contents of chromates as a part of paint material.

In this work influence of silicate fillers (microtalc and microwollastonite) on operational properties of coatings based on protective polymeric anticorrosive pastes VP-1 and VZP-1 with the lowered content of strontium chromates is investigated.

Influence of silicate fillers on protective properties of anticorrosive polymeric pastes with the lowered contents strontium chromate is investigated. By means of method of impedance spectroscopy it is established that partial replacement strontium chromate as a part of VZP-1 paste has allowed to increase protective properties of the coatings put on steel samples by microwollastonite. Partial replacement strontium chromate as a part of VP-1 paste has allowed to keep protective properties of coatings on steel samples at initial level. The received result can testify to availability of sinergy effect of microwollastonite in relation to anticorrosive pigments.

Hardness and adhesive durability of the coatings received on the basis of the protective polymeric pastes is investigated. Positive influenc

The paper presents a comparative analysis of the material of six carbide cutters made of WC-Co material. The structure of all samples is faceted tungsten carbide WC grains separated by layers of Co-binder. The studied samples are characterized by different chemical composition of carbon and inhibitor elements (Cr, V). The paper presents the calculated data of the optimal values of the carbon content, at which all carbon goes to the formation of WC grains. The inhomogeneity of the structure (clusters of large WC grains and "islands" of the Co-binder) is caused by deviations of the carbon content from the optimal value.

It is shown that the dependence between grain size and hardness is inversely proportional. Conversion of grain size to the specific fraction of the interfacial surface allows obtaining a direct relationship with the values of hardness. At the same time, the reduction of WC grain to 0,3 microns leads to a significant increase in the hardness of the material due to a strong increase in the interfacial surface of WC/Co.

The use of magnetic methods of structure estimation in order to reduce time costs is experimentally justified. The WC grain size and Co-phase fraction can be estimated by measuring the coercive force and saturation magnetization, and the value of the volume fraction of the Co-phase can be obtained directly from the measurements. The inverse dependence of WC grain size and coercive force is explained. The determining factor for the growth of coercive force is the increase in the proportion of interfacial boundaries WC/Co, which are the boundaries of the domains of the ferromagnetic Co-binder. In this case, the method is applicable only in the absence of porosity in the material, which can distort the measurement results.

In order to inhibit the growth of carbide grain, all manufacturers of carbide ma

Growth of volumes of output of products from nonmetallic materials demands introduction in manufacture of products from them modern highly productive technologies. In this connection in the given work possibility of use of laser radiation for cutting details from organic glasses is considered, are spent comparative strength tests of samples received by means of laser and mechanical cutting. As results of researches on influence of thermal radiation laser beam cutting on residual pressure in plexiglass and in particular on it «silverfirmness» are resulted.

The article presents the features of the destruction of fibrous MCMs system Ti–SiC under cyclic loads under the review of foreign scientific and technical literature. Abroad, the MCMs system Ti–SiC is developed for critical aircraft engine parts, which must have high performance and long life. In this regard, the study of the reaction of a material to a mechanical load under cyclic loads is an integral part for predicting the life of parts.

The paper presents the main factors affecting the nature of fracture and the fatigue life of fibrous MCMs system Ti–SiC under cyclic loads with different asymmetry coefficients. The influence of fiber packing density, volumetric content, reinforcement patterns on the nature of fracture and the durability of fibrous MCMs system Ti–SiC is considered. It is noted that due to the mismatch of the thermal expansion coefficient of the matrix and the fibers, residual stresses are formed in the MCMs, which affect the subsequent reaction of the material to mechanical stress. This effect is especially reflected in alternating loads. It should be noted that the residual stresses in the MCMs at the “fiber–matrix” interface are lower in the MCMs with the hexagonal packing of the reinforcing fibers than wi th the square packing of the reinforcing fibers. It is shown that at a low volume content of fiber in the MCMs, the destruction of the material occurs with the predominance of crack propagation from reinforcing fibers; at a high volumetric fiber content, matrix alloy cracking predominates. It was revealed that the characteristic damage to the MCMs under cyclic loads are cracks at the fiber-matrix interface in the reaction layer, delamination of fibers from the matrix, delamination between layers with different fiber orientations, cracks in the matrix, transverse cracks in the fiber, slip bands.
The stages of destruction of fibr