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The process of making a weld using the heat-resistant EP693 alloy (Ni–Cr–W–Co–Co–Mo system) to make assemblies and components for gas-turbine engines (GTEs) is considered based on laser welding using a TruLaser Cell 7020 CO2 installation operating in the pulse-periodic radiation mode. EP367 (Ni–Mo–Cr–Mn) additive wire is used to obtain the weld. The effect of thermal treating is studied to estimate the change in structure and properties both in the weld-adjacent area and in the weld. The results are used to examine the structure of the weld and its breaks. The physics and mechanical properties of the weld are evaluated. The greatest durability limit is estimated for welds at a level of 2 × 106 cycles. The feasibility of using a laser-welding heat-resistant dispersion hardened nickel alloy is evaluated to make support and stator shells for GTEs. It is established that complex thermal treatment (quenching and aging) provides for the optimum values of strength at room temperature and at high temperatures. It is also responsible for the short-term strength of welds. According to the strength calculations made for the support and stator of GTE shells and experimental data, the strength of welds made using pulse-periodic laser welding results in a strength safety factor between 1.35 and 3. This technology is proposed for industrial application to make shell parts and assemblies to be used in GTE support and stator in order to improve the quality of welds with a reducing time of high-temperature heating to bring down power consumption.

This paper presents the results of research on the synthesis of aluminum alloys of the Al–Si–Mg (Ak7ch), Al–Si–Mn (AK12), Al–Si–Cu–Mg (AK6M2), and Al–Mg–Mn (AMg5) systems using dispersed waste: beverage cans (Al–Mn–Mg system), sawdust of a cast alloy (Al–Si–Mg system), and twisted chips of deformable alloys of the Al–Cu–Mg and Al–Mg–Mn systems. A study of the microstructure of waste in the initial state is performed and the typical sizes of the main phases are determined. The main criteria for the quality of recyclable waste are determined: the purity (kp), contact with the atmosphere (ka), and maximum recovery of metal (ММе). Based on the proposed criteria, the waste is graded according to recycling efficiency. The lowest total score is assigned to cans of waste. Sawdust from the AK9ch alloy had the highest score. Experiments on the synthesis of Al–Si–Mg (Ak7ch), Al–Si–Mn (AK12), Al–Si–Cu–Mg (AK6M2), and Al–Mg–Mn (AMg5) alloys have shown that the usable yield varies from 82 to 96%. The minimum yield of usable material is set for the AK12 alloy, whose charge composition is dominated by beverage-can waste. The chemical compositions of the alloys in terms of the content of the main alloying and impurity elements meets the requirements of regulatory documentations. Tests of mechanical properties have shown that the synthesized alloys have a guaranteed margin of strength and plasticity in comparison with the requirements of regulatory documentation. Based on metallographic studies, it is found that the microstructure of synthesized alloys does not contain nonmetallic inclusions and gas porosity. Unmodified and modified samples from the Al–Mg–Mn alloy (AMg5) are subjected to cold rolling in several passes until cracks form. On the sample from an unmodified alloy, cracks appear after the tenth pass. The modified alloy sample withstands 12 passes before cracking. The degree of deformation in the thickness of the sample from the unmodified alloy is 60.5%; for the modified one it is 67.2%.

The effect of the structure of the initial charge density in liquid and solid states, as well as on the temperature–time parameters of the process of solidification of the AK6M2 alloy (Al–6% Si–2% Cu), is shown. To obtain a coarse-crystal charge (C charge), part of the melt is crystallized in ceramic forms in a sand backfill with a cooling rate of ~0.5–1.0°C/s. The fine-crystal charge (F charge) in the form of thin ingots weighing 0.2–0.3 kg is obtained by crystallization of the melt in cast-iron cold molds with ~5.0–10°C/s. Further, the charge billets are separately melted, re-refined and degassed, and the samples are poured to determine the gas content and density in the liquid (dL) and solid (dS) states. It is established that structural information from the original charge of the alloy is stable in the solid–liquid–solid system. Direct thermal analysis is used to find that the melt obtained from the F charge hardens at low temperatures: the decrease in liquidus temperature tL is 3°C; the temperature of the beginning of solidification of the eutectic is reduced by 10°C, and the temperature of the end of solidification of a eutectic is 3°C in comparison with the melt of the C charge. At the same time, the formation of α-Al and eutectic dendrites in the melt from the F charge occurs 0.4 and 0.6 min more quickly, respectively. The results obtained on the Paraboloid-4 installation show that a smaller number of pulses throughout the studied temperature range passes through the melt from the F charge, which confirms its increased density when compared to the alloy from the C charge. Thus, for the melt from the F charge, the values of the degrees of compaction were –ΔJl ~ 278.66 and –ΔJe ~ 129.83 imp/s and, for the melt from the C charge, –ΔJl ~ 302.9 and –ΔJe ~ 163.47 imp/s. The values of the phase-transition temperatures determined by anomalies on the temperature dependence Jt practically coincide with the results of direct thermal analysis. The main technological recommendations of management by structural information in aluminum alloys are formulated from the position of the phenomenon of structural heredity.

Based on studies of fractional, chemical, and phase compositions of Al-containing slags of different origin, it is established that they are multicomponent systems consisting of metal and nonmetal parts. The nonmetal part includes water-soluble and water-insoluble compounds. A practical flowsheet of recycling of Al-containing slags is proposed with the purpose of its further use as the secondary refractory dusting material (SRDM). The positive effect of the SRDM on the quality of refractory ceramic molds for investment casting and the surface finish of aluminum pilot castings is established. Its use promotes a ninefold increase in strength of refractory ceramic molds when compared with the quartz sand mold and an increase in gas permeability by 15 and 33% when compared with molds made of fused alumina and quartz sand, respectively. The formation of refractory ceramic mold formed based on the SRDM is investigated. The interaction mechanism of the dusting material particles with the suspension is substantiated from the viewpoint of colloidal chemistry. When forming the layers of the ceramic mold using the SRDM, negatively charged aluminum hydroxide micelles are formed. The interaction of oppositely charged Al(OH)3 and SiO2 micelles promotes the close engagement of the secondary refractory dusting material particles to each other. The theoretical substantiation of the formation of the ceramic mold layers with the application of the SRDM makes it possible to explain the decrease in the roughness characteristics on the surface of AK9ch alloy castings for the investment casting by a factor of 3.7 when compared with standard production processes.

Solders of the Al–Cu–Si system (A34 brand) and Zn–Al–Cu system (Welco52 brand) are investigated. It is found that the A34 solder (Al–28% Cu–6% Si) melts and crystallizes in a narrow temperature range (~18°C). Solidus and liquidus temperatures of the A34 solder are ~508 and ~526°С, respectively. Solders of the Zn–Al–Cu system (Zn–4% Al–2.5% Cu) have an eutectic composition that provides melting and crystallization at a constant temperature of ~389°С. Densities of studied solders in liquid and solid states are investigated. Their values for the solder of the A34 brand are 3.02 and 3.32 g/cm3, respectively, and, for the zinc solder, 6.28 and 6.69 g/cm3. The influence of casting conditions on the structure of cast alloys in the form of rods with a cross-section area of 13, 10, and 5 mm2 is investigated. The main structural components of solder alloys refine with a decrease in the cross-section area. Dendrites of the aluminum-based solid solution and CuAl2 phase refine in the microstructure of the A34 solder. Dendrite sizes of the zinc-based solid solution most noticeably decrease in the zinc solder. The largest castability is characteristic of alloys fabricated from rod solders with a cross section of 5 mm2 for studied gaps in the sampling of 2.0, 1.5, and 1.0 mm. The zinc solder of the eutectic composition has the best castability when compared with the A34 solder: this characteristic for the melt formed from the zinc-based solder rod with a cross section of 5 mm2 and a gap width in the sampling of 2.0 mm is 100% (the melt of the A34 solder formed from the rod of the same cross section has a castability of 98%). The results of experiments on soldering plates made of the AK12 alloy and sheets made of the AMts alloy show the presence of a tight boundary in the “solder–base material” system, as well as the absence of discontinuities in the form of pores and unsoldered regions. An insignificant interpenetration of solder alloys into the base material is observed, especially when soldering cast plates made of the AK12 alloy.

A comparative study on the influence of fabrication methods of AlTi4 master alloys on the grain size of Al3Ti intermetallic compounds is performed. It is found that an increase in the cooling rate during the solidification from 10–15 K/s (the crystallization in a hot cast iron mold and plate 30 mm in thickness) to 60–65 K/s (the crystallization in a cold cast iron chill mold; the rod 20 mm in diameter and 170 mm in length) promotes an increase in length and thickness of needle crystals of intermetallic compounds almost twofold (from 397 × 23 to 215 × 13 μm). Herewith, a decrease in electrical conductivity and an increase in the master alloy density in the solid state are observed. The modification of the master alloy melt by the addition of magnesium in an amount of 0.5 wt % determines the formation of homogeneous fine needles of intermetallic compounds 98 × 3 μm in size. The magnesium addition insignificantly decreases electrical conductivity and density when compared with the AlTi4 master alloy crystallized at the same cooling rate (60–65 K/s). The grain refinement of aluminum of the A97 grade and AK9ch alloy (the Al–Si–Mg system) by these foundry alloys with the same amount of introduced titanium (0.01 wt %) exert hereditary influence on the density and electrical conductivity, as well as on the marcograin (A97) and aluminum dendrites (AK9ch). The maximal modifying effect is characteristic of the AlTi4 master alloy containing magnesium in an amount of 0.5 wt %. Its introduction into the alloy promotes the formation of aluminum dendrites of 10 μm in size in an amount of 1427 pieces/mm2 in the alloy structure. When modifying the AK9ch alloy by the master alloy crystallized with cooling rates of 10–15 K/s, dendrites 28 μm in size in an amount of 672 pieces/mm2 are formed in the alloy structure. It is proposed to use the determination procedures of density and electrical conductivity for the express evaluation of the modifying efficiency of master alloys.

Herpes simplex virus type 1 is a highly contagious worldwide prevalent infection, which, once it enters the organism, persists during its whole lifetime. According to World Health Organization estimates, about 3.7 billion people under the age of 50 years (90% of the human population) are infected with by HSV-1 worldwide. The important role played by ribonucleases (RNases) in protection of the cell and whole organism from viruses has been confirmed by a considerable body of data that allow considering RNases not only as immune system components, but also as a basis for development of the new antiviral drugs. The purpose of the present work was to demonstrate the antiviral activity of the RNase from Bacillus pumilus (binase) toward HSV-1 at the cell entrance and reproduction stages. Virus treatment with binase in the concentration of 100 μg/mL for 60 min reduced virus replication in the bovine kidney epithelial cell culture MDBK by 100 times compared with untreated virus. Development of cytopathic effects produced by untreated virus in the cells grown on the medium with binase was retarded by 7 h compared with the growth of virus-infected cells on the medium without binase. It may be suggested that HSV-1 treatment with RNases reduces its ability to enter the cell; antiviral action of RNases toward the intracellular virus is realized at the initial stage of virus reproduction.

A comparative investigation on the influence of AlZr4, AlZr10, and AlSc2 modifying master alloys, as well as magnetic-pulsed treatment (MPT) on density (in the liquid and solid states), electrical conductivity (in a solid state), and macrostructure of AMg5 and AMg6 alloys is performed. Mater melts are poured into special facilities providing cooling rates during the crystallization of ~102, ~103, and ~106C/s. Master alloys are introduced into the melts in an amount of 0.01% by the modifier element. It is shown that the modifying treatment of the melts by additives of nucleating master alloys promotes an increase in alloy densities in liquid and solid states. The electrical conductivity of alloys with additives of AlZr4 and AlZr10 master alloys lowers. The introduction of the AlSc2 master alloy increases in electrical conductivity of AMg5 and AMg6 alloys. This effect is established for the first time and requires additional investigations. It is established that, when compared with AlZr4 and AlZr10 master alloys, the AlSc2 master alloy prepared by crystallization in a water-cooled roll crystallizer most strongly affects the physical properties of alloys. It also provides the maximal macrograin refinement. MPT of alloys according to the axial effect scheme, similarly to the introduction of modifying master alloys, promotes an increase in the density of alloys in liquid and solid states. Electrical conductivity increases after MPT like after the addition of the AlSc2 master alloy into the melts. Alloy macrograin refining during MPT is comparable with the modification with the AlZr4 master alloy. Based on comparative investigations, it is concluded that MPT can be attributed to physical modification methods. It is proposed to use the determination procedures of density and electrical conductivity for the express evaluation of the modifying efficiency of studied effects.

An increase in the sum of alloying elements in industrial silumins causes the formation of excess intermetallic phases in their structure. When introducing modifiers in such alloys above a certain amount, structural components are coarsened because of overmodification, which can cause a decrease in the mechanical properties of cast alloys. The optimal consumption of the modifying microcrystalline remelt decreases from 0.6 to 0.3 wt % with an increase in the sum of alloying elements in alloys from 7.35% (AK7ch) to 14.3% (AK10M2N). When using the AlTi5 master alloy, the optimal amount of introduced titanium decreases from 0.05 to 0.01% and, in the case of the AlTi5B1 master alloy, from 0.02 to 0.01%. The modifying effect of the AlSr10 master alloy enhances with an increase in the silicon content with smaller amounts of strontium introduced into alloys. It is shown that the consumption of the metallic modifier depends on its modifying ability, as well as the sum of alloying elements in the modified silumin.

An experimental setup developed in cooperation between the Institute for Energy Problems of Chemical Physics and the Joint Institute for High Temperatures for studying processes that occur during laser sublimation and for modeling thermophysical and chemical processes in situ at high temperatures in large-scale facilities is described.

The influence of treating the melts by electromagnetic acoustic fields on the structure and properties of Al–12% Si and Al–20% Si binary alloys is investigated. In the course of experiments, the frequency of the electromagnetic field induced in the loop antenna varies as 500, 1000, and 2000 kHz. The melts are treated after their degassing and refining. It is established that this treatment method of the melts leads to a reduction of the total preparation time of alloy by 12% on average. The short-term treatment of the melts by electromagnetic acoustic fields promotes the refinement of the main phase components of alloys and an increase in their mechanical properties. When treating the Al–12% Si eutectic alloy with a frequency of 500 kHz, α-Al dendrites are refined from 30 to 22 μm and eutectic Si crystals are refined from 13 to 10 μm. When treating the Al–20%Si eutectic alloy with a frequency of 1000 kHz, eutectic Si crystals diminished from 8 to 5 μm and these of primary Si diminished from 90 to 62 μm. The ultimate tensile strength of the Al–12%Si eutectic alloy increases 13% under the mentioned treatment modes, while the relative elongation increases 17%; as for the Al–20% Si eutectic alloy, the same characteristics increases 9 and 65%, respectively. Based on these investigations, it is concluded that the selection of the treatment parameters of the melts of the Al–Si system by electromagnetic acoustic fields should be determined by the silicon content in the alloy. It is necessary to treat the melt by waves with a higher oscillation frequency with an increase in the silicon concentration. This treatment method makes it possible to form the modified fine-crystalline structure of alloy and, consequently, improves their mechanical properties. It can be successfully used when fabricating fine-crystalline foundry alloys and in the production of alloys of the Al–Si system. To determine the optimal treatment parameters depending on the structure of the initial charge and alloy nature, additional investigations are required.

Computer modeling of main force factors when treating aluminum alloys by pulsed magnetic fields according to the radial and axial effect schemes is performed. It is established that, when using the radial scheme, the shock wave, which appears in the melt after a single pulse, affects its entire bulk for 40 μs; when using the axial scheme, this time is 416 μs. Experimental studies for industrial silumins AK6M2 and AK10M2N have confirmed the presence of a stable modifying effect under the magnetic pulsed treatment (MPT), notably, dendrite sizes of the α-Al phase and eutectic silicon crystals decrease, density and electrical conductivity increases, and alloy strength and plasticity in a cast state increase. Based on the experimental investigations, it is concluded that the MPT is most manufacturable for the axial effect scheme.

Forms of the condensed phase created under the action of a high-power CO2 laser pulse (power, 4 J/pulse; λ = 10.6 μm; pulse duration, 1.5 μs) on optical sapphire (Al2O3) solid targets are investigated. The ablation products emitted from the laser crater and the particles formed in the space above the surface of the target are collected using witness samples oriented in a predetermined manner with respect to the laser crater. Forms of the condensed phase are studied via electron microscopy and atomic force microscopy. Conclusions are drawn as to the mechanisms of formation of particles with different shapes and structures, including Al2O3 vacuum hollow microspheres (hollow bubbles).

XLPE-insulated cables and wires are becoming more widespread. For this reason, it is becoming necessary to control the state of insulation over its total operating life. Online monitoring of the effects on the insulation and determination of its remaining life becomes possible using modern equipment. In this paper, a method of determining the remaining lifetime of the cross-linked polyethylene insulation of the powertransmission line is presented. An insulation-aging model developed at the previous stage of the research was used. It is proposed to control the destructive effects on the insulation and calculate the remaining life based on the obtained data. The results of the research showed that the probability of failure is subject to the normal character of distribution (Gaussian distribution) as the insulation in the process of operation is exposed to a large number of effects (partial discharges, thermal actions, effect of the environmental factors, etc.). The remaining lifetime is defined as a function of inverse failure probability. The proposed method can be used to develop a set of devices for determining the remaining life of polyethylene insulation.

Factors causing the solid-phase dispersal of particles of alloying elements in the aluminum melt depending on their nature are considered. It is shown that the particles can be fragmented under the effect of uniform tensile stresses appearing due to the particles heating. The reasonability of using additional external effects (for example, magnetic-pulsed treatment of the foundry-alloy melt) to intensify the assimilation of silicon in liquid aluminum and provide the microcrystalline structure of the foundry alloy is substantiated theoretically and confirmed experimentally by the example of the Al–20 wt % Si foundry alloy.

It is established experimentally that internal local pressure is the physical cause of the self-organization of atomic displacements discovered earlier in multiferroics of the BiFeO3 type, activated by the action of an external impulse (γ-irradiation, electric shock). The main method of research is Mossbauer spectroscopy on nuclei of 57Fe.

The influence of the structure of charge bars, overheating temperatures, and isothermal holding time of Al-5 wt % Cu melts on their properties in solid and liquid states is investigated. It is revealed using the express method that the density of melts prepared from fine-crystalline charge bars (F-c charge) has reduced values compared with the melts prepared from coarse-crystalline charge bars (C-c charge). This peculiarity is retained over the entire studied range of overheating temperatures (760–1060°C). The influence of the structure of initial charge bars manifests itself in the second generation (after melting and crystallization from the corresponding overheating temperatures): alloys fabricated from the F-c charge have a smaller dendritic parameter α-Al and increased density and electrical conductivity compared with the alloys made from the C-c charge. It is shown that the involvement of deformed aluminum and copper waste into the charge composition provides a finely dispersed structure and increased density of Al-5 wt % Cu alloys in the solid and liquid states.

The influence of dispersity of charge silicon and structure of initial charge alloys on the density of silumins of the Al-Si system is investigated using the improved express-method for determining the melt density. It is established that the structure of charge materials substantially and stably affects this characteristic, which should be taken into account in preparation technologies of alloys of the Al-Si system.

Delayed (up to several months) transformations in the atomic structure induced by the external action (electric shock) are observed for the first time in a class of nonmetals in BiFeO3 multiferroic.

It was shown that irradiation of the crystals with high-energy (up to 55 MeV) γ-rays leads to the prolonged self-organization of atomic displacements. A tiny portion (at about 10−9 of the sample volume) of the initially excited atoms organize the entire crystal volume with respect to the time and the space.

The authors look into the potentiality of efficiently using natural mineral grain concentrates as bearing elements in the abrasive layer of diamond wheels in order to improve their performance in grinding operations.

A study is performed to find ways for efficient use of bearing elements in the form of layered compacts or milled Kiborite in the working layer of superabrasive wheels in order to improve the wheel performance in grinding processes.

The aim of the present paper is the theoretical investigation of the mechanical properties of carbon nanostructures of graphene and single-wall carbon nanotubes by using nanoscopic and macroscopic approaches. The nanoobject structures in free and deformed states were considered and the corresponding energies were computed in the framework of quantum mechanics methods by using the original software package of semi-empirical programsNDDO/sp-spd (developed in the Institute of Applied Mechanics, Russian Academy of Sciences) in parallel computations. The nanostructural deformations were prescribed in the approximation of the mechano-chemical deformation coordinate. The deformation forces were described by the energy gradients in selected coordinates of microscopic deformations. The mechanical characteristics of nanoobjects such as Young’s modulus, rigidity coefficients, works done in deformation, critical stresses, and relative elongations in fracture were calculated in the framework of the macroscopic linear theory of elasticity; the deformation forces determined by quantum mechanical calculations were used in the corresponding relations. It was found that the mechanical characteristics of single-wall carbon nanotubes (CNT) depend on their diameter and chirality, and the deformation properties of a graphene sheet are asymmetric with respect to two normal extension modes directed along the “zigzag” and “armchair” on the sheet edges. The calculated mechanical characteristics are in good agreement with the experimental data known fromthe literature, in both the values and the deformation asymmetrywith respect to different deformation modes.

A model of the motion of coal suspension in a hydraulic centrifugal classification unit with a toroidal separating rotor is considered. In simulation, the motion of the suspension is divided into stages. For each stage, differential equations are derived; their solution permits recommendations regarding the optimal design parameters and operating conditions.

A model of the motion of coal suspension in a hydraulic classification unit with a toroidal separating rotor is considered. In simulation, the motion of the suspension is divided into stages. For each stage, differential equations are derived; their solution permits recommendations regarding the optimal design parameters and operating conditions.

The addition of pyrolytic slag obtained from tire casings to coking batch is considered, along with methods of processing rubber goods and the products obtained. Analysis of the pyrolytic liquid indicates that its addition to coal batch will yield metallurgical coke of normal strength.

The need to improve coal enrichment stems from the sharp deterioration in the coal being enriched (increasing ash and moisture content, content of small classes, rock content, etc.), which results from the widespread mechanization of mining operations, the development of high-ash deposits, and dust suppression [1].

The previously found anomalies of radioactive decay of Mossbauer isotopes have been successively interpreted on the basis of the model of a “wave field” in a source saturated with its own decay products.