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Features of the structure of a layered material welded by explosion of high-strength titanium alloy and tool roller steel with an intermediate layer of the structural low-carbon steel have been studied. The structural transformations occurring in materials upon their dynamic interaction have been analyzed. Particular attention is paid to the structure of vortex zones formed at the interfaces of billets of various steels, as well as structural steel and titanium-based alloy. The structural analysis methods made it possible to fix stable and metastable joints appearing upon the explosive welding of various metals. To reveal features of structural transformations caused by prolonged heating, billets of titanium alloy and structural steel were also joined by diffusion welding. It has been shown that, in the course of the diffusion welding process, a continuous layer of stable brittle intermetallic compounds is formed along the entire interface of the welded materials. In the explosively welded materials, the intermetallic phases are distributed locally and, thus, they have a weaker embrittlement effect.

A number of experimental studies of melt motion and droplet ejection caused by pulsed plasma load include the measurements of the shape of surface after the solidification of target. The measured shape may be different from the one during the heating stage because of melt motion. In present paper the evolution of this perturbations is treated as capillary waves on the melt surface. The dispersion relation for capillary waves taking into account viscosity and limited depth of liquid was used. The numerical estimations for the melt surface behavior are done for tungsten samples irradiated at BETA facility.

Experimental research on behavior of rolled tungsten plates under intense transient heat loads generated by a powerful (a total power of up to 7 MW) long-pulse (0.1–0.3 ms) electron beam with full irradiation area of 2 cm2 was carried out. Imaging of the sample by the fast CCD cameras in the NIR range and with illumination by the 532 nm continuous-wave laser was applied for in-situ surface diagnostics during exposure. In these experiments tungsten plates were exposed to heat loads 0.5–1 MJ/m2 with a heat flux factor (Fhf) close to and above the melting threshold of tungsten at initial room temperature. Crack formation and crack propagation under the surface layer were observed during multiple exposures. Overheated areas with excessive temperature over surrounding surface of about 500 K were found on severely damaged samples more than 5 ms after beam ending. The application of laser illumination enables to detect areas of intense tungsten melting near crack edges and crack intersections.

The effect of annealing on the evolution of an ultrafine-grain structure and carbides in a 06MBF steel (Fe–0.1Mo–0.6Mn–0.8Cr–0.2Ni–0.3Si–0.2Cu–0.1V–0.03Ti–0.06Nb–0.09C, wt %) has been studied. The grain–subgrain structure (d = 102 ± 55 nm) formed by high-pressure torsion and stabilized by dispersed (MC, M3C, d = 3–4 nm) and relatively coarse carbides (M3C, d = 15–20 nm) is stable up to a temperature of 500°C (1 h) (d = 112 ± 64 nm). Annealing at a temperature of 500°C is accompanied by the formation in regions with a subgrain structure of recrystallized grains, the size of which is close to the size of subgrains formed by high-pressure torsion. The average size and distribution of dispersed particles change weakly. The precipitation hardening and the increase in the fraction of high-angle boundaries in the structure cause an increase in the values of the microhardness to 6.4 ± 0.2 GPa after annealing at 500°C as compared to the deformed state (6.0 ± 0.1 GPa). After 1-h annealing at 600 and 700°C, the microcrystal size (d = 390 ± 270 nm and 1.7 ± 0.7 μm, respectively) increases; the coarse M3C (≈ 50 nm) and dispersed carbides grow by 5 and 8 nm, respectively. The value of the activation energy for grain growth Q = 516 ± 31 kJ/mol upon annealing of the ultrafine-grained steel 06MBF produced by high-pressure torsion exceeds the values determined in the 06MBF steel with a submicrocrystalline structure formed by equal-channel angular pressing and in the nanocrystalline α iron.

The purpose of the research was to form a Ti-Ta-N- system bioinert coating on Ti6Al4V alloy surface as well as to study its structure and properties. The main contribution of the research is in the following. Electro-explosion spraying of tantalum coating on VT6 titanium alloy surface was pioneered in the research. After that the processing of the coating by low-energy high-current electron beam and subsequent nitriding was carried out in a single technological cycle. It has been established that a nanocrystalline coating based on tantalum, nitrogen and titanium was formed as a result of the technological operations. The phase composition of the coatings has been detected. The variations in crystal lattice parameters being formed in coating of phases and coherent scallering regions of these phases depending on power density of electron beam have been determined. Structural characteristics of the coatings at nano- and microlevel have been detected. Tests of coatings for nanohardness, the Young modulus, wear resistance and friction factor have been carried out. By all technical characteristics Ti-Ta-N-system coating exceeds titanium of VT6 grade. The cause of the increase in mechanical characteristics of the Ti-Ta-N-system coating is their nanostructural state and strengthening phases. Tests for proliferation activity of fibroplasts and antimicrobial activity have shown better results in comparison with VT6 titanium alloy as well. It is due to escape of vanadium ions from VT6 alloy into nutrient cell medium and their destructive effect on cell cultures. Variations in proliferation and antimicrobial activity develop due to amplification of cell proliferation. A complex of the obtained characteristics makes it possible to recommend Ti-Ta-N-system coating for its application as a bioinert coating on different implants in furure.

In this work we present simple grapheme-based system for low-resource speech recognition using Babel data for Turkish spontaneous speech (80 h). We have investigated different neural network architectures performance, including fully-convolutional, recurrent and ResNet with GRU. Different features and normalization techniques are compared as well. We also proposed CTC-loss modification using segmentation during training, which leads to improvement while decoding with small beam size.

The application of electron-beam processing enabled to obtain the mirror luster of electroexplosive coating surface of CuO-Ag system, to reduce the roughness without the loss of the composite material, to homogenize the surface layer of the coatings to the whole thickness of the coating being equal to 40 μm. The utilization of the selected regimes of pulsed electron—beam processing results in the realization of the processes of surface layer structurization of electroexplosive coating of CuO-Ag system. The phase composition of electroexplosive coating of CuO-Ag system after electron—beam processing presents the following phases: Ag, Cu2O, Cu64O and Cu. The electroexplosive coating of CuO-Ag system fail after 3000 cycles of switching on / switching off in the course of the accelerated electroerosion resistance tests. During the accelerated electroerosion resistance tests the electrical resistance is acceptable to the weak—current electrical contacts and is within the interval from 5.8 to 14.8 μOhm. The wear resistance tests have shown that EES of copper is accompanied by ≈3.3-fold increase in wear resistance of the modified layer; in this case, ≈1.3-fold increase in the fiction coefficient is observed. Nanohardness of coating layer varies within 280 MPa to 290 MPa at the average hardness value being 866.5 MPa. Young modulus varies within 24.3 GPa to 71.7 GPa at the average value of the modulus of 49.6 GPa.

We have examined the new phase formation and compositional variations in the coatings produced by detonation spraying of Ti3Al powders in atmospheres of different chemistry. The composition of the spraying atmosphere was varied by changing the O2/C2H2 ratio used for the detonation. In the coatings sprayed at an O2/C2H2 ratio of 0.87 and 1.05, certain deviations of the Al/Ti ratio have been observed relative to the sprayed powder. In these coatings, the Ti3Al phase was found along with TiN and Ti2N formed due to the reaction of the heated particles with nitrogen used for powder injection. The amount of TiN increased with increasing explosive charge and a concomitant rise in the particles temperature. Under O2/C2H2 ratios equal to 1.50 and 2.00, significant losses of Al were detected, the coatings being composed mainly of titanium oxides. This study shows that detonation spraying conditions excluding severe oxidation of Ti3Al can be found as well those facilitating oxidation with an associated loss of Al in the deposits.

For the first time, electroerosion-resistant coatings of the CuO–Ag system were obtained by electro-explosive spraying. The coating structure was investigated by atomic force microscopy and scanning electron microscopy. The formed coating is a homogeneous composite material consisting of a silver matrix and CuO inclusions located in it. The composite electro-explosive coating of CuO–Ag system is obtained on copper electric contact of contactor KPV-604. Tests of sprayed coatings for electrical erosion resistance under arc erosion conditions were carried out. A formation mechanism of hierarchical levels of the structure of electro-explosive coatings was suggested. The mechanism is based on theoretical concepts of the formation and evolution of fractal aggregates with diffusion-limited and cluster-cluster aggregations of the CuO. Based on the electrical properties of silver and copper oxide, the dependence of electrical contact resistance on the number of on/off cycles in the process of testing for electrical erosion resistance is substantiated.

This paper presents a brief review of research made by the authors to determine feasibility of using a titanium-based bilayer material in industrial applications. One layer, corrosion preventive, is formed by surface alloying with highly corrosion-resistant doping elements, in particular, Ta, Nb and Zr. These elements have significantly higher corrosion resistance than titanium. Applying them on the titanium substrate allows formation of a coating resistant, in particular, to boiling strong acids. Resistance of obtained coatings in said media is many times higher than that of titanium or stainless steel. The coatings are formed using a high-penetration electron beam ejected to the atmosphere. This article contains references to findings of previous works and offers some new data.

Results from different facilities for plasma-surface interaction (PSI) studies are compared and their relevance to each other and conditions of ITER transient events are discussed. For PSI studies different types of devices were used including open traps, tokamaks, linear plasma machines including quasi-stationary plasma accelerators, electron beams and lasers. The same damage thresholds were demonstrated with different techniques. At energy loads corresponding to ITER transient events (edge localized modes (ELMs), disruptions, etc.) only macroscopic erosion mechanisms are important. They are cracking, droplet formation and macroscopic mass losses of the target. Cracking occurs during cooling stage after irradiations. Details of plasma stream parameters are of secondary importance for cracks formation; only target temperature plays a role. Macroscopic mass losses strongly correspond with melting of a thin surface layer and heat loads play a key role for melting. Heat flux defines the targets surface erosion.

Wide-area (2 cm2) high-power (up to 7 MW) submillisecond electron beam source was applied for generation of intense pulsed heat loads on tungsten sample. Various diagnostics sets were used for in-situ research of the surface damage: IR imaging of the front view of the target, capturing of the reflection pattern of continuous wave laser radiation, recording of intensity of thermal radiation from several spots of the surface. Sample was exposed to a various heat loads near and above melting threshold. Formation of the crack network on the surface and its development with successive pulses was observed. Two-dimensional temperature distribution was obtained after heating at the cooling stage. Melting and spalling of material were shown on severe damaged target. Propagation of the cracks along the surface at a depth of 0.1 – 0.2 mm was revealed with transverse microsections. Circular motion of the molten layer was found with subsequent exposures.

This paper presents the results of structural investigations and results of tribological and microhardness tests of the coating obtained by electron beam cladding of a Ni-Cr-Si-Fe-B self-fluxing alloy on low-carbon steel. After electron beam treatment high-quality dense layer with a thickness of 1.2-1.8 mm was obtained. The structure of the coating consisted of dendrite crystals based on y-Ni-solid solution and eutectic with complex composition. Microhardness of the coating achieves 370 HV. Wear-resistance of the coating obtained by electron-beam cladding technique was 1.6-fold higher than that of low-carbon carburized steel.

The structure and microhardness of surface layers, obtained by non-vacuum electron beam cladding of Ti-Mo-C powder mixture on a steel substrate after different types of heat treatment, were investigated. After cladding samples were heat treated in a furnace at 200...500 °C, as well as quenched at 860 ° C and then underwent high-temperature tempering. Heat treatment of cladded coatings induced tempering of martensite and precipitation of cementite particles (Fe3C). Transmission electron microscopy of the samples after heating and holding at 300 ° C revealed precipitation of nanosized cubical TiC particles. The formation of hard nanosized particles led to the surface layer microhardness growth. The highest level of microhardness (which was 1.2...1.5-fold higher in comparison with coating microhardness after heat treatment) was achieved after heating of the claded material at 300 °C and 400 °C Additional quenching of samples at 860 °C did not increase the microhardness level.

Conjugated polymer-based organic photovoltaic devices (OPVs) have been intensively studied, since they are advantageous over regular inorganic devices. However, there is still no complete understanding of the functionality of conjugated polymer-based organic active layers. Due to this, research into the processes of microstructure formation will improve morphology control and optimization and enhance performance and productivity. In this study we used in situ measurements of conductivity and X-ray diffraction analysis in grazing incidence X-ray diffraction (GIXD) geometry to investigate the structure of light-sensitive layers produced by coating from solutions and based on poly(3-hexylthiophene) (P3HT) mixtures as donors with various fullerene acceptors: [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) and indene-C60 bisadduct (ICBA). The structure of films produced by coating from solutions was studied by large-angle GIXD. Ex situ and in situ methods (under external voltage applied) were used to detect high compatibility between the donor and acceptor for ICBA-based films. The time dependences of changes in current and intensity of the (100) peak of P3HT demonstrate that the maximum emerges simultaneously. A two-step increase in intensity of the (100) peak of P3HT was observed for films containing PCBM as an acceptor. In situ studies of the structure confirm that the joint donor–acceptor structure is formed as the solvent evaporates. Atomic force microscopy studies of the surface roughness of films containing different acceptors demonstrate that they are characterized by different morphologies.