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In this paper, we studied the phase and elemental composition of the surface layer of die steel 5KhNM subjected to electro-explosive sputtering deposited composite TiC–Ni–Mo coating and subsequent pulsed irradiation with a high-intensity submillisecond electron beam. The modes of electron-beam processing providing the formation of a dense, with a mirror gloss, surface layer with a submicrocrystalline structure based on titanium carbide and intermetallic compounds based on Mo, Ni, and Ti are determined. The electron-beam processing of an electro-explosive coating in the melting mode is shown to lead to the formation of a structurally uniform and concentration-uniform surface layer. TiC–Ni–Mo coatings have a 1.26 times higher wear resistance compared to die steel 5KhNM used as a substrate. The microhardness of the formed coatings is 450–2400 HV, the nanohardness is 25.5 GPa, and the modulus of elasticity is E = 398 GPa.

The electroexplosive method is used to obtain Ti-Zr coatings on the titanium dental implant surface (alloy VT6). Scanning and transmission electron microscopy as well as X-ray diffraction analysis are used to determine the elemental and phase composition; the morphology and defect substructure of the coating is studied. Hardness and Young’s modulus, friction coefficient and wear resistance of the formed coating are determined. The coating formed by electric explosion is found to be multielement and multiphase and to have a submicro-nanocrystalline structure.

The effect of the structural transformations during non-vacuum electron-beam cladding of amorphous boron powder on the hydroabrasive wear resistance of the surface layers of a chromium-nickel austenitic steel is studied. It is shown that the cladding yields a coating with densely arranged borides. An x-ray method is used to show that the modified layer consists virtually fully of Fe2 B iron borides. This structure raises the hydroabrasive strength of steel 12Kh18N9T by a factor of 1.5 – 2.

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.

The study has been conducted in line with the current approach to investigation of materials obtained by considerably deep surface alloying of the titanium substrate with Ta, Nb, and Zr. The thickness of the resulting alloyed layer was equal to 2 mm. The coating was formed through weld deposition of a powder with the use of a high-voltage electron beam in the air. It has been lately demonstrated that manufactured such a way alloyed layers possess corrosion resistance which is significantly higher than the resistance of titanium substrates. It has already been shown that such two-layered materials are weldable. The study objective is to investigate the feasibility of rolling for necking the sheets with the Ti-Ta-Nb anticorrosion coating with further fourfold decrease in their thickness. The research is also aimed at investigation of the material properties after rolling. Anticorrosion layers were formed both on CP-titanium and on VT14 (Ti-4Al-3Mo–1 V) durable titanium alloy. The results of chemical composition determination, structure examination, X-ray phase analysis and mechanical properties observations (including bending properties of the alloyed layers) are presented in the paper. The combination of welding, rolling, and bending enables the manufacture of corrosion-resistant vessels and process pipes which are made from the developed material and find technological application.

The research was devoted to studying unlubricated tribological behaviors of γ-TiAl-based coatings in the temperature range 25–400 °C. These γ-TiAl-based intermetallic coatings alloyed with Fe or Mn were formed on CP-Ti workpieces using a non-vacuum electron beam deposition. The microstructure, phase and elemental analyses proved the formation of γ-TiAl and appearance of the ternary phases (Laves and G-phases). It was shown that friction coefficients obtained for three materials were barely different but their fluctuations were strongly dependent on surface oxidation and the phase composition. It was found that the Ti-45Al-8Mn (at.%) coatings consisting mainly of γ and α2 phases had lower wear resistance in comparison with the Ti-42Al-7Fe (at.%) and Ti-57Al-13Fe (at.%) coatings. Whereas the Ti-57Al-13Fe (at.%) coating contained γ and G phases possessed better wear resistance as compared to that of Ti-42Al-7Fe (at.%) coating with the structure represented by the γ matrix and a eutectic (α2 + Laves phases). The microprobe analysis, scanning electron and optical microscopy, and XPS measurements revealed the formation of highly oxidized mechanically mixed layers after the sliding tests. The Ti-45Al-8Mn (at.%) coating subsurface consisted of Al2O3, Al, TiO2, and Ti sub-oxides, whereas for both Ti-Al-Fe coatings the formation of an initial oxide film consisted of a titanium dioxide (rutile structure), alumina, and a low amount of iron oxide (hematite structure) was revealed. Thermal softening of the counter body provoked the iron oxide growth in the wear traces of the coatings alloyed with Fe. Tribooxidation behaviors of Ti-Al-Fe coatings may be interpreted as an example of adaptation the as-deposited structure and phases to high-temperature sliding condition and therefore these coatings can be recommended for protection of the titanium alloy components.

In the present study the effect of the thermal-mechanical processing regime—cold high-pressure torsion (HPT) at room temperature, cold HPT followed by annealing at 773 K (500 °C), and warm HPT at 723 K (450 °C)—on the peculiarities of the microstructure and microhardness of a Mo-Nb-Ti-V-0.08C microalloyed steel was analyzed. HPT processing resulted in high deformation and refinement of the initial structure and produced an ultrafine-grained microstructure featuring different morphologies with fine (

In the present research a novel method of increasing in mechanical characteristics (wear resistance, friction coefficient, Young's modulus and nanohardness) of titanium implants is proposed. A complex processing was used including electroexplosion spraying of hafnium coating and subsequent electron-beam processing combined with nitriding. Electroexplosion spraying was carried out in the modes ensuring the formation of microrelief on the boundary with titanium substrate. Electron beam processing of hafnium coating surface allowed its smooth surface to be provided and the coating to be nanostructurized. Smooth surface makes the coating a more commercially profitable for selling the medical products and nanostructurization ensures a high level of mechanical and biolodical properties. The obtained coating of Ti-Hf-N system contributes to the increase in wear resistance by the factor of 17.4 and simultaneous increase in friction coefficient by 7%. The coating also ensures the increase in nanohardness by the factor of 2.05 and the increase in the Young modulus by 13% in comparison with Ti-6Al-4V alloy. Nitriding allowed the strengthening of hafnium coating by nitrides. In the coating 40–50 μm in thickness hafnium is distributed homogeneously and is presented in the phases of HfN, Hf and HfTiN2. The comparison of the phases being formed in the coating and the structural components of coatings' surface depending on processing mode is made. After combined processing the surface of the coating is presented by three different structural components. The proliferative activity of fibroblasts and antimicrobial activity were studied as biological properties of the coating in the present research. The structure of the coating is studied by the methods of modern physical materials science. The complex analysis carried out enables one to recommend the coating for subsequent tests on experimental animals (rabbits) and further commercial production of strengthened titanium implants. To study osteointegration the samples of the experimental implants with bioinert coatings obtained in the present research are to be introduced into rabbits' osseous tissue in future.

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 phase transformations of the alloy Ti-40 mas % Nb after tempering and severe plastic deformation are studied. The phase transformations of the alloy according to the type and conditions of external influences are analyzed using methods of XRD, SEM and optical metallography. It is determined that inverse phase transformation of the metastable α''-phase to equilibrium β-phase is carried out after severe plastic deformation. Complete phase transformation α'' → β is typical for the mode, which consists of three pressing operation with the change of the loading axis in cramped conditions, followed by a multi-pass rolling in grooved rolls.

The structural transformations of the Cr-Ni austenitic steel surface layers during non-vacuum electron beam cladding of the amorphous boron and wetting agents (Cr, Ni, Fe) were investigated. Gas- and hydroabrasive wear resistance of the obtained materials was evaluated. It was shown that the modified layer almost completely consisting of the complex borides (Cr,Fe)хBy is formed during the cladding. The structure provides improving the wear resistance of the steel by 2-5 times. The thickness of the formed layers is 2.5-2.7 mm. The coating formed by beam current 23 mA with Fe as wetting agent has the best set of properties.

The influence of the cladding rate on the structure and microhardness parameter of coatings obtained by non-vacuum electron beam treatment of Ni-Cr-Si-B powder mixtures was investigated. Modified layers characterized by the gradient structure and consist of dendritic grains and a eutectic located at the grain boundaries. It was found that the lowest microhardness level (300 HV) was characteristic of the coatings obtained when the workpiece was moving relative to an electron beam with a speed of 10 mm per second. This treatment regime allowed obtaining high-quality coatings 2.5 mm in thickness. However, a large thickness of fusion penetration led to the interfusion of the base metal with a coating material and a decrease in the concentration of alloying elements in the coating. Reducing the lifetime of the liquid phase during treatment prevented intensive diffusion processes. Increasing the treatment velocity to 20 mm per second doubled the cladded layer microhardness (up to 650 HV).

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.

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.

The paper explores the effect of a modifier based on ultrafine powders of refractory metal oxides on the change of structural state, phase composition and mechanical properties of cast iron of ИЧХ28Н2 (Russian grade). It was shown that the modifier added to the melt does not change the phase composition of ferrite-austenitic matrix and carbides and is not carbide-forming. Material microstructure changes only due to the presence of a large amount of crystallization nuclei during the casting cooling. It was established that the modification increases the ultimate stress limit by 53%, plasticity by 10.7%, corrosion resistance by 15%, and leads to the reduction of friction factor and linear wear due to the decreasing of structural elements: carbide phase and austenitic-carbidic eutectic.

This paper presents the results of studies of the structure and properties of coatings produced by cladding 10 mm thick titanium plates with titanium–tantalum powder mixtures using an electron beam extracted into air. A mixture of CaF 2 and LiF salts was used as a flux that protected the heated material from the air atmosphere. The electron beam power was 33.5 kW, the velocity of the sample relative to the beam 10 mm/s, and the beam scanning frequency 50 Hz. High-performance titanium–tantalum layers 2–2.5 mm thick with a tantalum content of 3.9–22.4 wt% were obtained. The surface layers have a dispersed α(α′)+β structure. The tensile strength of the alloy containing 3.9% tantalum is 620 MPa. Increasing the Ta content to 22.4% increases the tensile strength to 735 MPa. For the coating material containing 22.4 wt% Ta, the rate of corrosion in a 68% solution of boiling nitric acid was 190 times lower than that for unclad titanium. The conditions of formation of the layer structure by high-velocity electron-beam cladding of powder materials are significantly different from equilibrium. For this reason, the resulting materials are characterized by a number of features, including a high degree of dispersion of the structural components and inhomogeneous chemical composition.

Composite WC/Co + MoS 2 coatings were deposited onto steel substrates by Computer Controlled Detonation Spraying using three spraying modes: very cold, cold and normal. Maximal content of MoS 2 in a sprayed powder was 10 wt.%. Characterization of coatings was made with chemical and phase analyses, microhardness measurement, morphology and microstructure investigation. X-ray diffraction study shows that residual MoS 2 exists only in coatings obtained at very cold and cold spraying modes. At normal spraying mode complete decomposition of the solid lubricant occurs during spraying. From the engineering point of view, the coating applied at the cold mode using a powder containing 10 wt.% MoS 2 is the most promising. Such a coating has microhardness of 650 HV 0.2 and a porosity of 10%.

The aim of the work was to clad Ti-Ta-Nb coating on a substrate of pure titanium. Cladding was carried out by non-vacuum electron-beam treatment. As a result a good quality coating thickness of about 2 mm was obtained. Microstructural and microhardness tests were conducted. Dendritic structure and the borders of the former grains of β-phase were revealed. At the microlevel, the coating has a martensitic structure. The average hardness of coating is about 4000 MPa.

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.

The effect of the initial heat treatment (quenching or tempering) of low-carbon steel (Fe-Mo-Nb-V-C) on special features of the ultrafine-grained structure and microhardness produced by high-pressure torsion was investigated. High-pressure torsion promotes the more apparent refinement of structural elements of the steel (dpr = 55 nm for the quenched state and 74 nm for the tempered state) and an increase in structural homogeneity of microhardness of quenched specimens in comparison with tempered ones. Experimental results reveal a high significance of the initial structural state for the final deformation-processed microstructure and microhardness (radial distribution) of steel specimens.

The effect of initial heat treatment on peculiarities of ultrafine-grained structure and on homogeneity of strength properties (microhardness) through the specimens was studied in low-carbon steel Fe-Mo-Nb-V-C processed by high-pressure torsion. Three initial states, i.e. (I) normalized, (II) quenched and (III) quenched and tempered, with different morphologies and grain sizes were used. A noticeable effect of the initial state on characteristics of ultrafine-grained structure processed by high-pressure torsion was observed: decrease in the initial grain size causes more effective grain refinement and formation of higher value of microhardness in the middle part of disk radii (dav = 91 nm and 700 HV for normilized state, dav = 98 nm and 770 HV for quenched state and dav = 100 nm and 600 HV for initial quenched and tempered state).

The paper presents the results of the investigation of VT6 titanium alloy subjected to electro-explosion alloying with TiB2 and irradiation with pulsed electron beam. It was established that electro-explosion alloying resulted in a high level of roughness of the surface layer with high adhesion of the modified layer and matrix. Further irradiation of the material with electron beam resulted in the smoothing of the surface of alloying and formation of a porous structure with various scale levels in the surface layer. It was also established that the energetic exposure causes the formation of a gradient structure with a changing elemental composition along the direction from the surface of alloying.

Special features of plastic deformation and fracture of excess cementite segregated under the conditions of high-temperature carbon supersaturation of steel are studied by the methods of light and scanning electron microscopy. It is shown that regularly oriented flakes of excess cementite with a lamellar structure are formed within the former austenite grains. The cementite flakes oriented along the, rolling plane fracture by a brittle mechanism forming numerous fragments. The behavior of free cementite under the conditions of cold rolling depends on the orientation of the flakes in the specimen. The mutual shift of the layers allows coarse cementite formations to deform under the action of compressive stresses without cracking.

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.

1. Among the materials investigated the pitting formation process takes place most intensely in the M2 plasma coating. The resistance of the PG-SR4 coating to contact-fatigue failure is at the level of a similar characteristic of U8 steel with bainite structure after isothermal processing. 2. The controllable thermoplastic hardening of the U8 steel with subsequent treatment to bainite results in an increase in its fracture toughness, increases the resistance to contact-fatigue failure in comparison with normal isothermal processing. 3. For increasing the resistance to contact-fatigue of protective coatings, it is necessary to reduce their porosity, increase their cohesion strength and the strength of bonds with the base metal.

Bands of localized plastic flow 20–30 μm wide and up to 3000 μm long are formed in deep drawing of steel 18YuA. The development of the bands is completed with the formation of cracks due to exhaustion of the reserve of plastic properties in the steel. The special features of the process of localized flow in drawing steel 18YuA are considered.