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In this study, Ti-Zr coatings were fabricated by ion-assisted arc-plasma deposition in vacuum. The phase composition, morphology and mechanical properties of the developed thin films were studied. The addition of Zr into Ti resulted in the formation of α’- (Ti,Zr) and α”- (Ti,Zr) solid solutions and mechanical properties change of the prepared alloys. It was revealed that the increase of Zr content in the coating resulted in the increase of nanohardness. The deposited coatings possess reduced modulus of elasticity 77–98 GPa, which is significantly improved compared with Ti substrate, which reveals a modulus of elasticity of 110 GPa. Furthermore, nanoindentation results demonstrate significant improvement of the elastic strain to failure and plastic deformation resistance of the Ti-Zr coatings with the increase of the content of Zr from 11 wt % to 22 wt%. Thus, it is likely that Ti-Zr coatings obtained by ion-assisted arc-plasma deposition possess a high biomedical potential due to synergetic combination of biocompatibility and biomechanical properties.

The paper studies the formation of TiAlN and TiSiB coating by macroparticle filtered vacuum arc plasma, high-frequency short-pulsed plasma immersion and repetitively pulsed high-current ion beam implantation. A new design of an axially symmetric plasma filter is described. The samples were pretreated by a repetitively pulsed high-current ion beam and plasma source “Rainbow-5” and high-frequency (100 kHz) short-pulsed (8 μs) metal plasma immersion ion surface treatment. Macroparticle-filtered metal plasma deposition was realized under ion beam mixing or using high-frequency short-pulsed negative bias. The work yields the surface morphology, elemental composition, and mechanical properties of coatings.

This paper describes the effect of plasma immersion ion implantation (PIII) of titanium on hydrogenation behavior and mechanical properties of Zr–2.5Nb alloy. Surface morphology and depth distribution of elements in the surface layer of the samples were analyzed by scanning electron (SEM) and atomic force microscopy (AFM), and glow-discharge optical emission spectroscopy (GDOES). Hydrogenation was performed at 673 K temperature and 2 atm pressure. It was found that after titanium implantation a diffusion barrier is formed, accumulating hydrogen and preventing hydrogen penetration in the sample volume. The microdroplet content significantly influences the hydrogenation behavior of the zirconium alloy. Hydrogen sorption rate decreased 18.3 times and 4.3 times using filtered and unfiltered PIII, respectively. The mechanical properties of titanium-implanted zirconium layer were improved. The degradation of the mechanical properties after hydrogenation was revealed.

The changes of the phase composition, structure and physicomechanical properties of Ti‑40 mas % Nb after severe plastic deformation are investigated in this paper. By the methods of microstructural, X-ray diffraction analysis and scanning electron microscopy it is determined that phase and structural transformations occur simultaneously in the alloy after severe plastic deformation. The martensitic structure formed after tempering disappears. The inverse α'' → β transformation occurs. The structure consisting of oriented refined grains is formed. The alloy is hardened due to the cold working. The Young modulus is equal to 79 GPa and it is less than that of initial alloy and close to the value obtained after tempering. It is possible that Young modulus is reduced by additional annealing.

The effect of the pulsed electron beam (PEB) treatment on the structure and morphology of the hydroxyapatite (HA) coating deposited on the surfaces of titanium substrates by radio frequency magnetron sputtering was elucidated. The structure, composition and morphology of the samples were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results collected from SEM experiments demonstrated that the HA film was smooth and featureless. The samples were irradiated by PEB using an electron beam energy density of 0.1 J cm−2, electron beam pulse duration of 50 μs, pulse repetition frequency of 5 Hz, and number of pulses N=50 and N=150. After PEB treatment with N=50, the coating exhibited a much finer uniform surface morphology, playing a crucial role in the enhancement of the mechanical properties of the HA-coated titanium substrate. The surface of the HA film treated with N=150 was still smooth and featureless. The XRD data demonstrated that PEB treatment of HA films produced only a slight decrease in the HA phase content. The combination of these two techniques opens the possibility of preparing high quality HA layers.

The aim of the present study is to investigate hydrogen permeation through an aluminium oxide coating Al 2 O 3 , which was deposited on the nanocrystalline titanium (NCTi) using two methods: deposition from a substrate saturated with hydrogen, and saturation of Al 2 O 3 /NCTi system from an ambient medium (electrolyte, gas, plasma). Films were deposited onto the surface of specimens by magnetron sputtering. While performing the deposition, hydrogen diffused throughout the depth of the film; however, diffusion was restricted to the area near the film–substrate interface, affecting less than 50% of the thickness of the film. Film–substrate interface is significantly broader (compared to the deposition on an unsaturated substrate), and metallic hydroxides are formed in the interface. Saturation of Al 2 O 3 /NC Ti system with hydrogen was performed using three methods: electrolytic method, saturation from the high-frequency discharge hydrogen plasma, and from hydrogen atmosphere at high temperature and pressure. The analysis of the saturation process shows that the Al 2 O 3 coating can protect the metal surface from hydrogen permeation only in the case of its operation in the conditions of contact with aqueous solutions.

Ti-Al-N coatings were deposited on high-speed steel substrates by filtered vacuum arc deposition (FVAD) during evaporation of aluminum and titanium cathodes. Distribution of elements, phase composition, and mechanical properties of Ti-Al-N coatings were investigated using Auger electron spectroscopy (AES), X-ray diffraction (XRD), transmission electron microscopy (TEM) and nanoindentation, respectively. Additionally, tribological tests and scratch tests of the coatings were performed. The stoichiometry of the coating changes from Ti0.6Al0.4N to Ti0.48Al0.52N with increasing aluminum arc current from 70 A to 90 A, respectively. XRD and TEM showed only face-centered cubic Ti-Al-N phase with preferred orientation of the crystallites in (220) direction with respect to the sample normal and without precipitates of AlN or intermetallics inside the coatings. Incorporation of Al into the TiN lattice caused shifting of the (220) reflex to a higher 2θ angle with increasing Al content. Low content and size of microdroplets were obtained using coaxial plasma filters, which provides good mechanical and tribological properties of the coatings. The highest value of microhardness (36 GPa) and the best wear-resistance were achieved for the coating with higher Al content, thus for Ti0.48Al0.52N. These coatings exhibit good adhesive properties up to 30 N load in the scratch tests.

By the results of X-ray analysis, microstructural analysis, nanohardness and elastic modulus measurements it was defined that non-equilibrium phases during the process of crystallization are formed in the titanium-niobium alloy with 40wt.% of Nb. The minimum of non-equilibrium phases is formed at the Ti-40wt.% Nb alloy. The uniform grain structure, which consists of β-phase grains with the minimum of elastic modulus, is formed in the alloy ingot. Such structure and complex of properties allows using this alloy for severe plastic deformation.

A set of methods has been applied to study the properties of titanium oxide and oxynitride coatings on steel. It is established that the coatings consist of two phases with a nanocrystalline and an amorphous structure with a high proportion (∼50 %) of grain boundaries; anatase is the dominant crystalline phase. The obtained results can be applied in the development of coatings for stents as well as for manufacturing hydrogen accumulators.

A high-vacuum installation for the qualitative and quantitative investigation of the content of monatomic and molecular gases (hydrogen, oxygen, nitrogen, water vapors, gaseous hydrocarbons, CO2, CO, etc.) on the surface and in the near-surface layers of compact and porous materials is designed. Methods of radiation-stimulated and thermally stimulated desorption, as well as a technological method for degassing solid materials via electron irradiation, are achieved in the installation. The results of an investigation into the hydrogen content upon saturation and its emission from polycrystalline (average grain size d > 1μm) and submicrocrystalline (d < 0.1 μm) titanium under radiation and thermal effects are presented as an example of the use of the abovementioned methods.

A high-vacuum plant and methods for studying thermal and radiation-stimulated desorption from solid-state materials are described. Radiation-stimulated desorption was studied using an electron gun with a 1- to 120-keV beam energy, featuring a new technology of power supply units. Partial pressure gages with a sensitivity of up to 10−13 Pa were used to record mass spectra of residual gases. Results of studying thermal- and radiation-stimulated yields of hydrogen from submicrocrystalline samples of a BT-6 alloy are presented to demonstrate the serviceability of the created procedures.

OA gold This study reports the effect of titanium (Ti) microstructure on the mechanical properties and surface wettability of thin (

In this paper the latest results obtained for (Ti, Al)N, TiSiB coating deposition using a hybrid technology are presented. This technology includes several approaches. For sample pretreatment the repetitively pulsed high-current ion-beam and high-frequency short-pulsed metal plasma immersion ion surface treatment were used. An intermediate layer between coating and sample surface was formed by metal ion implantation using a high-current vacuum ion-beam and plasma source “Raduga-5”. The vacuum arc microdroplet-filtered metal plasma coating deposition was realized under ion mixing using high-frequency short-pulsed plasma immersion ion technology. It was experimentally shown that for deposition of TiAlN coatings, mono (Ti, Al) and multi-element (TiAl) cathodes can be used. Phase and elemental composition, structural state, and mechanical properties of (Ti,Al)N and TiSiB coatings were observed, and they are presented in this paper.

A 3 × 3 matrix of samples has been ion implanted with nitrogen at low-to-high doses and low-to-high current densities (dose rates). All samples show surface exfoliation which results in a loss of the implanted nitrogen and a consequent loss of the wear-resistant properties—a condition of over-implantation reminiscent of that observed with metal ion implantation. There is an uptake of post-implantation oxygen which is believed to form an amorphous TiO2 component in the surface leading to the well-established low frictional properties. This uptake decreases as the dose rate is increased and would lead to a loss of wear resistant properties. The work confirms that a dose of 3 × 1017 ions cm− 2 is optimal provided that the dose rate does not exceed the present industrial standard.

The surface morphology, chemical composition and microstructural evolution of the near-surface (up to 0.5 μm) layers of austenitic stainless steels (SS) 304L and 316L irradiated with a pulsed (2.5 μs) low-energy (20–30 keV), high-current (up to 30 kA) electron beam (2–10 J/cm 2 ) have been studied. It was revealed that the cratering on irradiation caused by the local overheating followed by explosive ejection of the material at the sites of localization of low-melting-point second-phase (e.g. FeS 2 ) particles having a low-thermal-conductivity occurs. The plate rolling stock SS 304L cratered far less than the rod stock one. Multiply repeated pulsed melting of SS 304L (plate) and 316L (rod) almost completely suppresses cratering and reduces the surface roughness compared to the untreated surface. Surface smoothing is accompanied by cleaning of the near-surface (≈50 nm) layer from O, C and N. As a result of fast (∼10 9 K/s) quenching from the melt, in the near-surface (≈0.5 μm) layer, a single-phase ( γ ) microstructure is formed with a grain size of 0.2–0.6 μm, which is almost two orders of magnitude lower compared to the untreated SS. The formation of such substructure allows to considerably enhance the electric strength of vacuum insulation and corrosion resistance of SS.

The results of the study of the pulsed plasma-immersion ion implantation of titanium in steel Cr18Ni10Ti depending on the time (dose) implantation are presented. It is shown that the change of the element and the phase composition of the surface layers and their microscopic characteristics and mechanical properties (hardness, wear resistance) depending on the implantation time is not monotonic, but follows to a certain rule. The possibility of interpretation of the obtained results in the thermal spike concept of the generation on the surface by the stable (magic) clusters is discussed. This concept follows logically from the recent studies on the plasma arc composition and from a polyatomic clusters-surface interaction.

The investigation results are presented for some processes occurring at different stages of strong adhesion coating and modified layer creation with the use of high-dose implantation and deep diffusive doping of elements under pulsed energetic impact. The investigations have been carried out on installation, providing the possibility of combined materials treatment with pulsed ion beams of power density ranged from 10 3 to 10 8 W/cm 2 . The facility includes an accelerator of high-power ion beams and sources of repetitively-pulsed metal ion beams and metal plasma flows. The possibility of the application of a high power ion beam pulsed energetic impact to intensify mass transfer and increase the depth of doping for a preliminary implanted impurity has been demonstrated. The results are presented concerning the formation of high quality thin coatings with wide buffer layers determining their adhesive strength by means of the method of combined treatment using a high power ion beam.

The life of TiN-coated tools can be improved by a post-coating ion implantation treatment, but the mechanism by which this occurs is still not clear. Nitrogen implantation of both physical-vapor-deposited TiN and CVD TiN leads to surface softening as the dose increases, which has been attributed to amorphization. In this study a combination of transmission electron microscopy and atomic force microscopy was used to characterize the microstructure of implanted TiN coatings on cemented carbide for comparison with mechanical property measurements (nanoindentation, residual stress, etc.), made on the same samples. Ion implantation leads to a slight reduction in the grain size of the TiN in the implanted zone, but there is no evidence for amorphization. Surface softening is observed for physical-vapor-deposited TiN, but this is probably due to a combination of changes in surface composition and the presence of a layer of bubbles generated by the very high implantation doses used.

Titanium nitride, TiN, is used as wear protective and decorative coatings in various applications. These coatings are deposited by standard industrial methods such as chemical and physical vapor deposition (CVD and PVD, respectively), including magnetron sputtering or its modifications [e.g. the plasma-enhanced magnetron sputtered deposition (PMD) method]. The coatings have different microstructures (size and morphology of grains, orientation, dislocation structure, residual stress, etc.) depending on the method used and the deposition regime. The results of comparative transmission electron microscopy (TEM) investigations of the microstructure of thin TiN coatings deposited by classical CVD and PVD, including PMD, are presented. The microstructure was studied in sections perpendicular and parallel to the coating surface. The grain size was estimated from dark field images and the residual stress was determined using the bend extinction contours in the bright field images. It was found that the coatings deposited by PVD and CVD methods have different grain microstructures and residual stresses. The CVD coatings have an equiaxed microcrystalline structure with very low levels of the local residual stress. The mean grain size is 0.4–0.6 μm. The PVD coatings (Balzers and Metaplas) have a non-equilibrium submicron grain structure with a high level of the local residual stress equal to 0.06–0.08E, where E is Young's modulus, and a mean grain size of 0.1–0.2 μm in the section parallel to the coating surface. The PMD coating structure is highly non-equilibrium nanocrystalline, with a very high level of residual stress equal to 0.13E and a much finer grain size of 0.06 μm.

Two versions of vacuum arc sources for producing accelerated ion beams and plasma flows are described. The sources are distinguished by use of a dc vacuum arc discharge for plasma generation on the basis of a simple linear or coaxial plasma gun with extended large area (70 300 and 1500 cm2) cathodes and microparticle filtering system. The dc vacuum arc discharge combined with the diode extraction system enables us to use the single source for dc mode of plasma flow formation and repetitively pulsed mode of ion beam generation. Experimental and numerical results are presented on the repetitively pulsed accelerated ion beam formation in the vacuum arc sources with large area cathodes.

The surface morphology, chemical composition, microstructure, nanohardness, and tribological properties of a film (Cu)–substrate (stainless steel 316) system subjected to pulsed melting with a low-energy (20–30 keV), high-current electron beam (2–3 μs, 2.8–8.4 J/cm 2 ) have been investigated. The film was deposited by sputtering a Cu target in the Ar plasma of a microwave discharge. To prevent the local delamination of the film due to the cratering, the substrates were repeatedly pre-irradiated with 8–10 J/cm 2 . Single pulsed melting of this system resulted in the formation of a diffusion layer of thickness 120–170 nm near the interface, irrespective of the energy density. The layer has the subgrain structure consisting of the γ-Fe-solid solution and submicrometer or nanocrystalline Cu particles. The nanohardness and the wear resistance of the surface layer of thickness 0.5–1 μm, including the molten film and the diffusion layer, non-monotonically vary with energy density, reaching a maximum in the range of 4.3–6.3 J/cm 2 . As the pulse number is increased to five in the same range of energy density, the film dissolves in the substrate, and a ∼2-μm-thick surface layer is formed which contains ∼20 at.% Cu. Under these conditions, the segregation of Cu during resolidification leads to the formation of two-phase nanocrystalline layers separating γ-phase grains.

The paper presents the results of investigating the formation of vacuum-arc plasma flow cleaned from the microparticle fraction. The plasma filter design is based on plasma spread in a channel formed by electrodes located at an angle with the axis of an arc evaporator. The effects of magnetic insulation of the electrodes and the positive near-electrode potential drop on the mechanisms of charged plasma component spread are investigated. The results of the obtained experimental data are discussed.

The paper discusses examples of realizing the regimes of high-intensity and high-concentration ion implantation, and plasma deposition of coatings including the conditions of dynamic ion mixing using "Raduga-5", a source of accelerated ions and plasma based on the DC vacuum arc discharge. It is shown that when a target is treated with high average power beams, it is possible to dope a material at depths exceeding the projective ion range by an order of magnitude. Features of ion beam application at different stages of ion plasma deposition of coatings are considered. Examples are given for the formation of wide transition layers between the coating and the substrate under conditions of intensive ion mixing. Mechanisms of change in the properties of the coatings formed with decreasing microparticle fractions in the arc plasma stream are considered.

Results are presented for some processes occurring at different stages of strong adhesion of coatings and modified layers creation with the use of high-dose implantation and deep diffusive doping of elements under pulsed energetic impact. The investigations have been carried out to consider the possibility of combined materials treatment with pulsed ion beams of power density ranging from 10/sup 3/ to 10/sup 8/ W/cm/sup 2/. The facility includes the accelerator of high-power ion beams and the sources of repetitively-pulsed metal ion beams and metal plasma flows.

Phase composition, structural state, and mechanical properties of the ion-doped surface layers of Ni, Ti, and Fe targets with Al and Ti ions implanted into using the metal ion beam and plasma source Raduga 5 have been investigated. The high-intensity mode of implantation allowed us to obtain the ion-doped layers with the thickness exceeding the ion projected range by several orders of magnitude. By the transmission electron microscopy, it has been found that the fine-dispersed equilibrium intermetallic phases (Me3Al, MeAl) and the solid solution of aluminum were formed in the doped Ni, Ti, and Fe surface layers at the depth of up to 2600nm. The maximum dopant concentration reached 75%. It has been shown that the average size of the formed phases was of 70nm. The microhardness of the different target surface layers increased by 1.5–3 times. The wear resistance of the samples did not change within the temperature range of 300–700K.

Tribological behavior of Cu–MoS2 and Ag–MoS2 nanocomposite lubricant was studied. Cu nanoparticles produced by electrical explosion of copper wires and Ag nanoparticles prepared by electrospark erosion were employed as metal cladding modifiers of MoS2 nanolamellar particles. The tribological tests showed Cu–MoS2 and Ag–MoS2 nanocomposite lubricants changed the friction coefficient of the initial grease and essentially improved its wear resistance.

The complex installation for combined materials treatment with accelerated ion beams of different peak power and metallic plasma flows is described. The installation comprises the high-current repetitively pulsed vacuum arc ion source, high-intensity pulsed ion beam source, and direct-current vacuum arc plasma source combined with the plasma filter for plasma cleaning from the microparticle fraction. It has been found that the preliminary treatment of stainless steel samples with the high-power ion beam of nanosecond pulse duration results in the reduction of ion sputtering coefficient at the implantation of tungsten ions. It has been shown that the increase of maximum implanted tungsten concentration is influenced by changing the surface morphology and element structure of the samples affected by the high-power ion beam.