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Using the method of high-frequency ion-plasma sputtering (magnetron high-frequency deposition under conditions of ion-plasma assisted using a gas (argon) plasma generator «PINK») on the surface of a high-entropy CoFeCrMnNi alloy of non-equiatomic composition. Boron-containing coatings of the elemental composition Al – Mg – B and Mg – Ti – B with a thickness of 3 μm are formed. Using transmission electron diffraction microscopy, it was found that the coatings are amorphous-crystalline, i.e. contain nanosized 1.5-2 nm islands of the crystalline phase located in an amorphous matrix. It is shown that the coating deposition is accompanied by the formation in the substrate layer (high-entropy alloy) adjacent to the coating of a nanocrystalline structure with a crystallite size of 25-40 nm. At the boundaries of the crystallites, particles of iron boride of the FeB and Fe3B compositions are revealed, which indicate the penetration of boron into the substrate. The particle size of iron boride is 5-8 nm.

According to the technology of wire-arc additive manufacturing a nonequiatomic composition CoCrFeMnNi high-entropy alloy (HEA) was obtained. Deformation curves of samples in tension are plotted and analyzed after the HEA fabrication by the methods of wire-arc additive manufacturing (initial state) and after the electron-beam processing (EBP). The EBP results in a decrease in the HEA's strength and plastic properties. Along with a pit character of the fracture a presence of micropores and microlayerings are identified. A study of the HEA's fracture surface after the EBP except for regions with a ductile fracture mechanism revealed regions with a band (lamellar) structure. The area with a band structure increases with a growth in the beam electron density from 25% at 10 J/cm2 to 65% at 30 J/cm2. A diameter of separation pits in fracture bands varies in the limits (0.1–0.2) μm, which is considerably less than those of the remaining part of the HEA sample. An average size of crystallization cells formed in the EBP depends on the energy density of electron beam and increases from 310 nm at 15 J/cm2 to 800 nm at 30 J/cm2. A non-monotonous change in the scalar dislocation density, reaching a maximum value of ∼5.5 · 1010 cm-2 at a distance of 25 μm from the irradiation surface is revealed. It is suggested that defects being formed in surface layers in the EBP may be one of the reasons for decreasing the values of HEA strength and plasticity.

By the methods of transmission and scanning electron microscopy the effect of a carbon-fluorine containing additive in a flux of a silicomanganese slag with a low content of manganese oxide on the structural-phase state, defect substructure and fracture surface of an electric arc surfacing of low-alloy steel is investigated. A quantitative analysis of the parameters of structure, phase composition, dislocation substructure of the surfacing with the additive into a flux and without it is made. It is shown that the deposited metal with the additive into a flux has a layer surface structure. It is detected that a predominant fracture mechanism is a ductile fracture with a formation of the pit structure of the fracture. The areas of a quasibrittle fracture are much more rarely detected. The main structural constituent of the deposited metal are the α-phase grains. The second structural constituent of the surfacing is the pearlite grains of lamellar morphology whose relative content in the surfacing with the carbon-fluorine containing additive to a flux is three-fold higher than in the surfacing to a flux without it. In most cases the α-phase grains are fragmentary. The particles of iron carbide of a round shape of 20–80 nm in size are revealed in the α-phase grains of the deposited metal with the carbon-fluorine containing additive to a flux. The metal of the surfacing with the additive to a flux is characterized by the higher values of scalar and excess dislocation density and the amplitude of curvature-torsion of a crystal lattice.

This paper presents the results of structural studies of films with a thickness of up to 5 microns of high-entropy alloys of the AlNbTiZrCu system. The films were synthesized on metal and cermet substrates by deposition of a multielement metal plasma created by electric arc plasma assisted simultaneous independent sputtering of several cathodes. It is shown that the films are a layered material and have an amorphous-crystalline structure. It was found that irradiation of films with a pulsed electron beam (18 keV, 20 J/cm^2, 50 μs, 3 imp., 0,3 s^(-1)) is accompanied by crystallization of the material. It is shown that the resulting films are dominated by the compound of the AlNbTiZr composition with the lattice parameter of nm. On the basis of theoretical calculations, the structural data of the crystal AlTi0,86Zr0,95Nb lattice were obtained, mechanical and thermodynamic characteristics of this compound were determined.

Silumin (an alloy of aluminum with silicon) is a cheap industrial alloy with good corrosion resistance, high specific mechanical properties and good casting properties. As a result it has found wide applications in modern industry (aircraft and mechanical engineering, instrument making, shipbuilding, etc.). The aim of this work is to analyze the regularities of transformation of the structure and phase composition of the surface layer of a hypereutectic silumin ( Al - 22 wt % Si ), subjected to irradiation with an intense pulsed electron beam. It was found that irradiation of silumin with a pulsed electron beam ( 18 keV, 25 J / cm^2, 200 μs, 3 pulses, 0,3 s^(-1)) leads to melting of the surface layer up to 60 μm thick, the high-speed crystallization of which is accompanied by the formation of a submicro-nanocrystalline multiphase structure. It is shown that aluminum (a solid solution based on fcc crystal lattice) forms cells of high-speed crystallization; nanoscale particles of the second phases are located at the cell boundaries. Analysis of three-component state diagrams of the Al - Si - Fe - Cu system (the main elements of the studied silumin) demonstrated the possibility of forming a large number of two- and three-element compounds in the alloy under equilibrium conditions. It has been shown by diffraction electron microscopy that, along with three-element phases, phases based on four and, possibly, more elements are formed in silumin.

Ion nitriding is one of the most common methods of surface hardening of parts and tools. The purpose of this work is to identify and analyze the laws governing the transformation of the structure and properties of the surface layer of high-chromium stainless steel subjected to low-temperature nitriding in a low-pressure gas discharge plasma. It was found that the saturation with nitrogen ( 793 K, 3 hours) of austenitic high-chromium steel 20X23H18 in a low-pressure gas discharge plasma is accompanied by the formation of a plate type structure with alternating plates of austenite and iron nitride in a layer (55 — 60) μm thick (transverse plate sizes do not exceed 10 nm), the microhardness and wear resistance of which exceed the microhardness of the initial state by 6,5 times, wear resistance – more than 400 times.

It was established that comprehensive surface treatment of 12Cr18Ni10Ti (AISI 321) high-chromium stainless steel, combining the electro-explosive alloying with titanium and boron and subsequent irradiation with an intense pulsed electron beam, allows the formation of a multiphase submicro- nanocrystalline surface layer up to 60 µm thick, whose microhardness and wear resistance exceed the initial state microhardness by 7 times, wear resistance – by more than 9 times.

The analysis of diagrams of the state of the Fe – B – Ti, Fe – Cr – B and Fe – Cr – Ti systems is carried out, describing the phase converting into high-chromium stainless steel of 12Cr18Ni10Ti (AISI 321) alloyed by titanium and boron. It is shown that in the conditions of the high-speed tempering realized at the electro-explosive alloying by titanium and boron and irradiation by an intensive pulsed electronic beam, compounds from two elements are formed in the steel only.

The results obtained during the study of 20H13 steel subjected to a combined treatment including irradiation with a pulsed electron beam and nitriding in a plasma of a low-pressure gas discharge are presented. It is shown that nitriding of steel previously irradiated with an electron beam makes it possible to increase in 1,8 times the microhardness of the surface layer of 140 μm in thickness on the original sample and in 1,4 times on the sample after nitriding.

The results of structural studies of the formation of MAX-phases on the surface of titanium alloys synthesized as a result of combined treatment combining the electric explosive alloying and irradiation with a high-intensity pulsed electron beam are presented.

A thermodynamic analysis of phase transformations occurring during heat treatment of the alloy Fe-Cr-Ni-C, which is the basis of steel AISI 321, is carried out. The results of the analysis of the elemental and phase composition, the defect substructure of stainless steel caused by the irradiation with a high-intensity pulsed electron beam are presented.

The results of the analysis of the elemental and phase composition, the defect substructure, strength and tribological characteristics of the hypereutectic composition silumin in the molten state and after irradiation with high-intensity electron beam are presented. The formation of the modified surface layer with thickness of up to 1000 µm, having increased strength and tribological characteristics was demonstrated as a result of irradiation.

The paper presents a study of Cu-Zn-Al alloy that is proved to be a multiphase material. In the equilibrium state, α-phase (fcc crystal lattice) and β-phase (simple centered cubic lattice) can be formed in this alloy based on copper. It is shown that γ-phase can be formed due to the three-component alloy composition, and the different chemical composition of the Cu-based solid solution ( Zn or Al alloys), the different concentrations of its second element result in the formation of a certain amount of α- and β- phases within the one type of the crystal lattice that differ in its parameter. The possibility of the alloy powder synthesis is shown using the plasma-chemical techniques that allows the formation of X-ray amorphous and nanocrystal structure. A variety of binary phases characterized by Zn and Al concentration in the Cu-based solid solution is described in this paper. The experimental results show that plasma-chemical synthesis of metal alloy powders is accompanied by decomposition of chemical elements. Powders of the triple composition were not observed.

The results of silumin surface modification by combined method including irradiation by plasma produced in the electric explosion of conductive material followed by a pulsed electron beam treatment are presented. The formation of a multilayer polyphase sub-micro and nanoscale structure with high mechanical and tribological properties is revealed. The results obtained are discussed from the viewpoint of thermodynamics.

The studies of the phase and elemental composition, condition of the defect substructure of the surface layer of electrical grade copper M00 subjected electroexplosive composite coating deposition systems Cu-Mo and subsequent exposure of high-intensity pulsed electron beam. Identified modes of electron-beam processing, enable the development of compact, high-gloss surface layers with submicron and nano-crystalline structure based on molybdenum and copper.

In work are submitted data on evolution of structure and properties of a titanic alloy of BT6 and silumin after an electroexplosive alloying and radiation by an electronic bunch. Formation the MAX -phase of structure of Ti3SiC2 and Ti3AlC is established.