The aim of this study was to analyze the phase composition of metal films formed by plasma-assisted vacuum arc deposition due to evaporation of a near-equiatomic TiNbZrTaHf cathode. High-temporal- resolution data were obtained by an in situ X-ray diffraction analysis using synchrotron radiation. The use of this technique made it possible to identify the time interval of formation of the films and that of change in their phase composition. It was revealed that the film growth occurred in three stages. At the first stage of film deposition, (3 phase (bcc lattice, a = 0.34748 nm) was identified. At the second stage, an amorphous-crystalline phase formed, as evidenced by the rise in the background of the diffraction line in the angular range of 2 theta = 24-25 deg. At the third, final stage, the diffraction lines of omega phase (hexagonal lattice; a = 0.46636 nm and c = 0.27872 nm) and alpha phase (hcp lattice; a = 0.31261 nm and c = 0.47846 nm) were detected. After completion of the deposition process, the films contained 84 wt.% (3 phase, 14 wt.% alpha phase, and 2 wt.% omega phase.

Titanium dioxide coatings have been formed by vacuum-arc plasma-assisted method and their structure, phase composition and properties have been studied in detail. It is shown that the discharge current of the gas plasma source is one of the key parameters allowing to control the polymorphic composition of titanium dioxide coating, its hardness and wear resistance. Titanium dioxide in coatings is present in two polymorphic modifications: rutile and anatase, the relative content of which depends on the conditions of plasma assist. Titanium dioxide coatings, irrespective of the plasma assisted mode, are nanocrystalline material having a columnar structure.

The formation of nitride coatings based on the titanium (Ti), niobium (Nb), zirconium (Zr), tantalum (Ta), and hafnium (Hf) (i.e., TiNbZrTaHf) high-entropy alloy (HEA) was studied by in situ X-ray diffraction analysis using synchrotron radiation. HEA-based nitride coatings were formed as thin films (1.5-2 mu m) by plasma-assisted vacuum arc deposition. The multielement gas-metal plasma used was produced by evaporating a near-equiatomic TiNbZrTaHf cathode. In studying the thin film growth in situ with high time resolution, the VEPP-3 electron storage ring was used as a synchrotron radiation source. To verify the data of the in situ X-ray diffraction analysis, electron diffraction spectra of the films were obtained using transmission electron microscopy. It was found that the film growth was a multistage and multiphase process. The deposition of a metallic sublayer on the substrate before coating deposition (the first stage of film synthesis) was accompanied by the formation of a three-phase system represented by beta, alpha, and omega metallic phases, which were in an amorphous-crystalline state. The nitride layer formed on the metal substrate was presented by metal-nitride (MeN) and MeN* phases, which differed in the type of crystal lattice. The diffraction lines of the nitride phases were blurred, which might have been due to the nanocrystalline state (0.7-1.2 nm) of the film.

The paper proposes the reduction of the surface roughness and improvement of its strength properties for metallic materials and products fabricated by additive manufacturing. The proposed technique implies the creation of a 2 µm thick metal film on the doped surface layer by the vacuum arc deposition and pulsed electron-beam processing of the film/substrate system. The proposed technique of the film (Zr)/substrate (VT6) system processing provides a 25 times reduction of the surface roughness and improves its strength properties by 1.5 times.

Thin (3 µm) metal coatings with a columnar nanocrystalline bcc structure composed of crystallites of size 1.5–2.5 nm were formed from a near-equiatomic HfNbTaTiZr cathode through its plasma-assisted vacuum arc evaporation. The hardness of the coatings is 4.7 GPa. Their specific wear rate and friction coefficient measure 1.6 × 10–6 mm3 N–1 m–1 and 0.82, respectively.

High-entropy alloys based on refractory metals, possessing an unusual combination of physical, mechanical, tribological, electrophysical, etc. properties, can be recommended for use in various fields of industry and medicine. The aim of the work is to study the growth process of high- entropy alloys films of the Ti-Nb-Zr-Ta-Hf-Cu system in real time by X-ray phase analysis using synchrotron radiation. Experiments on the deposition of multielement metal films were carried out the VEIPS-1 setup developed at the Institute of high current electronics Siberian branch of the Russian academy of sciences for studying the processes of the film and coating formation on a synchrotron radiation source. The process of in situ thin film structure formation with high time resolution was studied using a synchrotron radiation source - the VEPP-3 electron storage ring, the Institute nuclear physics, Siberian branch of the Russian academy of sciences. It is shown that the deposition Ti-Nb-Zr-Ta-Hf-Cu plasma on a HG40 substrate is accompanied by the formation of an amorphous crystalline state represented by phases of the composition (presumably) Ti-Nb-Zr-Ta-Hf-Cu, TiZr, NbZr, and CuTiZr, formed at different stages of film deposition. The main phase is the Ti-Nb-Zr-TaHf-Cu composition.

Р а с с м о т р е н ы р е з у л ь т а т ы , п о л у ч е н н ы е п р и и с с л е д о в а н и и с т р у к т у р ы и с в о й с т в к е р а м и ч е с к и х п л е н о к н а о с н о в е в ы с о к о э н т р о п и й н о г о с п л а в а ( В Э С ) .К е р а м и ч е с к и е п л е н к и В Э С ф о р м и р о в а л и п у т е м о с а ж д е н и я н а м е т а л л и ч е с к и е п о д л о ж к и м н о г о э л е м е н т н о й г а з о -м е т а л л и ч е с к о й п л а з м ы , с о з д а н н о й и о н н о -п л а з м е н н ы м м е т о д о м п р и о д н о в р е м е н н о м р а с п ы л е н и и ч е т ы р е х к а т о д о в ( C u , Z r , N b , T i -5 0 % A l )

Zirconium nitride coatings are deposited by a vacuum-arc method at a low (0.01-0.04 Pa) nitrogen partial pressure in the modes without and with plasma assistance. The plasma assistance is provided by the operation of a gas plasma source based on a non-self-sustained arc discharge with thermionic and hollow cathodes. This new low-inertia method has not been practically studied in terms of formation of nitride coatings with different architecture (single-layer, multi-layer, gradient coatings). We note that the effect of plasma assistance (an increase of the nitrogen concentration in the nitride coating with the increasing nitrogen ion fraction in the gas-metal plasma) is practically unobservable in the ZrN coatings formed under the selected conditions. Furthermore, their phase compositions do not noticeably change and their physical, mechanical and tribological properties are not significantly improved.

Multielement nitride coatings of quasi-equiatomic compositions, (NbMoCrTiAl)N and (NbZrCu-TiAl)N, are synthesized by deposition on a substrate in vacuum from a multicomponent gas-metal plasma. This plasma is generated by a simultaneous independent vacuum-arc evaporation of the cathodes of the selected elements in a plasma-assisted mode in a nitrogen atmosphere. It has been established that the synthesized coatings are single-phase materials with a face-centered cubic crystal lattice. For the (NbZrCuTiAl)N coating composition, the crystal lattice parameter a = 0.44288 nm and for (NbMoCrTiAl)N – a = 0.40540 nm. The resulting nitride coatings have a nanocrystalline multilayer structure. Their microhardness depends on concentration and type of chemical elements, as well as on nitrogen pressure in the gas-metal plasma; it reaches 43 and 46.5 GPa for the (NbMoCrTiAl)N and (NbZrCuTiAl)N coatings, respectively.

A method for finishing the surface of metal materials manufactured by additive technologies with an intense pulsed electron beam, which can be an alternative to traditional processing methods, is presented. The optimal irradiation modes for VT6 titanium alloy specimens manufactured by metal powder fusion and 308LSi stainless steel specimens manufactured by electron beam welding are determined. It is shown that the presented processing method leads to a visual decrease in the porosity and a multiple decrease in the surface layer roughness (Ra) (by 20 times) of the VT6 titanium alloy manufactured by the additive method. The surface roughness of 308LSi stainless steel specimens manufactured by electron beam welding decreased by a factor of 2.1 in the longitudinal direction and by a factor of 5.2 in the transverse direction relative to the surfacing plane. It has been shown that the elemental composition, strength, and tribological properties of the specimens do not change after irradiation in optimal modes. Tensile testing of irradiated specimens revealed an increase in the tensile strength by 12

A developed vacuum-arc plasma-assisted method is applied to produce films of a high-entropy alloy from a multicomponent gas-metal plasma generated by the simultaneous independent evaporation of selected metal cathodes. New modes are revealed to allow the deposition of thin films of a high-entropy alloy, AlTiCrNbMo–N, with a nearly equiatom composition. The films are a multilayer nanocrystalline material with a body-centered cubic lattice, the parameter of which specifically depends on the concentration of elements in the alloy. The synchrotron-radiation technique demonstrates that films of the high-entropy alloy AlTiCrNbMo–N are stable when heated in air to temperatures not exceeding 620°C.

The development of alloys called high-entropy alloys, which consist of several (usually five or more) basic elements, in contrast to conventional alloys with one and rarely two basic elements, indicates the emergence of a new class of metallic materials with a unique combination of mechanical, physical, tribological, and other properties. The aim of this work is to analyze the results obtained in the study of the elemental and phase composition, and defect substructure of multilayer multielement nanostructured metal films (so-called high-entropy alloys of nonstoichiometric composition) by X-ray diffraction analysis and transmission diffraction electron microscopy. Films of high-entropy alloys are formed by depositing a metal plasma onto a substrate, which is formed as a result of the vacuum arc plasma-assisted simultaneous independent evaporation of cathodes of the following groups of metals: Nb, Mo, Cr, Ti, Al (sample 1) and Ti, Al, Cu, Zr, and Nb (sample 2). The elemental composition of the films is revealed. It is found that the obtained films are multilayer and have a nanocrystalline structure. Sample 1 is a single-phase material based on a MoNbCrTiAl solid solution with a body-centered cubic (bcc) crystal lattice with a parameter of 0.3166 nm. Sample 2 is an X-ray amorphous material. It is found that the microhardness of films 1 deposited on VK8 hard alloy turns out to be higher than that of films 2.

Nitride coatings based on the high-entropy alloy with the elemental composition of TiNbZrTaHf were formed by deposition onto a solid substrate in vacuum from a multi-component gas-metal plasma created by vacuum arc cathode evaporation with plasma assistance in a mixture of nitrogen and argon. It was shown that the coatings are a single-phase (FCC crystal structure; a = 0.4508 nm) nanocrystalline (2.5–3 nm) material with a hardness of 26 GPa and a Young’s modulus of 359.2 GPa.

The paper analyzes the structure and properties of metal, cermet, and ceramic NbMoCrTiAl high-entropy alloy (HEA) coatings formed on solid substrates by plasma-assisted vacuum arc deposition (from multicomponent gas-metal plasma through Nb, Mo, Cr, and TiAl cathode evaporation in argon and/or a mixture of argon and nitrogen). The analysis shows that all coatings represent a nanocrystalline (3–5 nm) multilayer film. The metal coating has a bcc lattice (a = 0.3146 nm). The ceramic coating has an fcc lattice (an uncertain lattice parameter due to highly smeared diffraction peaks). The coating hardness increases in the order of metal, cermet, and then ceramic, reaching 43 GPa at Young’s modulus equal to 326 GPa. When heated in air, the metal and cermet coatings start to oxidize at 630–640 °C, and the ceramic coating at 770–780 °C.

The results of studies aimed at synthesizing coatings of ceramic high-entropy alloys by the vacuum-arc plasma-assisted method with simultaneous evaporation of several cathodes are presented. The optimal regimes for deposition a nitride coating of the (NbMoCrTiAl)N composition were revealed. To determine the contribution of the ion current of each arc evaporator, the azimuthal characteristics of the ion current density of the arc evaporators and the PINK-P gas plasma generator were measured. It is shown that the formed coating had a non-equiatomic composition, and the concentration of metal atoms in the coating varied from 6.6 at

The paper analyzes the Cr-B film structure formed via argon plasma-assisted deposition on pretreated 12Cr18Ni10Ti stainless steel using the COMPLEX electron-ion-plasma setup (IHCE SB RAS, Russia, Tomsk). The analysis shows that after simultaneous deposition of chromium and boron, the Cr-B film represents a multilayer structure consisting of alternating amorphous boron and nanocrystalline chromium boride layers. At a total film thickness of 1 μm, the thickness of its amorphous and nanocrystalline layers measures 2.0-7.0 and 2.0-2.5 nm, respectively. The steel layer adjacent to the film contains Fe2B nanoparticles. Their presence in the steel is due to its preliminary electron beam irradiation and boriding. The micro-hardness of the Cr-B film is 29.0 GPa (standard deviation 4.1 GPa), and its Young's modulus is 200 GPa.

Multilayer cermet coatings based on a TiNbZrTaHf high-entropy alloy were produced on solid substrates by plasma-assisted vacuum-arc deposition. The assisting multicomponent metal-gas plasma was generated by evaporating TiNbZrTaHf cathodes in a gas mixture of nitrogen and argon. It was found that the coatings were nanocrystalline in structure (with nanocrystal sizes ranging from 2.5 to 4 nm). The metallic layer had a body-centered cubic lattice (a = 0.33396 nm), and the ceramic layer had a face-centered cubic lattice (a = 0.44465 nm). Transition layers formed between the substrate and the metallic layer and between the metallic and the ceramic layers were revealed. The hardness of the coatings was 36.7 GPa and their Young's modulus was 323 GPa.

The work is aimed at obtaining new knowledge about the structure and properties of high-chromium AISI 304 steel subjected to complex electron-ion-plasma saturation with boron atoms, which combines deposition of a boron and metal films and subsequent irradiation of the “film/substrate” system with an intense pulsed electron beam. An increase in the microhardness of the surface layer up to 21 GPa and wear resistance more than 20 times was revealed. The short duration of the modification process considered in the work (the total processing time is 1.5–2 hours), environmental friendliness (all processes take place in the vacuum chamber) and a minimal change in the structural-phase state and, consequently, the properties of the volume of the modified part (temperature of the specimen volume was 600–650 K) are emphasized.