Supersonic Spraying Research Articles

Reversible wettability of thermally treated Hanji decorated with supersonically sprayed ZnO nanoparticles

In this study, we aimed at transforming naturally superhydrophilic Hanji, a traditional Korean Han paper into its superhydrophobic version. This change is crucial for applications requiring water damage resistance, such as mold growth, abrasion, and degradation. The resulting superhydrophobic Hanji shows potential for diverse applications, including fabricating wallpaper, traditional window covers, and high-end wrapping paper. To achieve this, ZnO nanoparticles (NPs) were deposited on the surface of Hanji via supersonic spraying, resulting in morphological curvatures capable of accommodating nanoscale air pockets. Additionally, supersonic spraying facilitated the robust adhesion of ZnO NPs to the Hanji cellulose fibers. Notably, the hydroxyl groups from both ZnO and Hanji were removed through subsequent annealing, resulting in superhydrophobic ZnO-Hanji. The annealing-induced shrinkage and densification of Hanji enhanced its superhydrophobicity, a property not achieved using regular A4 paper. This substantiated the unique benefits of using Hanji to realize superhydrophobicity. The superhydrophobicity reverted to superhydrophilicity upon exposure to ultra-violet irradiation, initiating reactions of the –OH group from atmospheric moisture with electron–hole pairs on the ZnO surfaces. Consequently, tunable/reversible wettability of ZnO-decorated Hanji was achieved via simple supersonic spraying and annealing, without any chemical modifications.

Enhancing the piezoelectric coefficient of SrTiO3 nanocubes and PVDF film deposited by supersonic spraying for energy-harvesting nanogenerators

Many perovskites and their piezoelectric composites have been investigated for harvesting ambient mechanical energy over the past two decades; however, the prospects for their commercialization appear remote because of several practical challenges. Therefore, highly scalable supersonic cold-spraying technology was used to fabricate flexible piezoelectric films of poly(vinylidene fluoride) (PVDF) and a novel perovskite SrTiO3 (ST). Substantial shear stress was exerted on PVDF during cold spraying owing to the hydrothermally synthesized SrTiO3 nanocubes and supersonic velocity, and the resulting film delivered an effective piezoelectric coefficient (69.6 pm·V−1) as confirmed by piezo-response force microscopy. As a result, the piezoelectric nanogenerator yields a maximum power of 130 µW at a load resistance of 0.9 MΩ. The composite film exhibited durability for 21,000 tapping cycles with 20 N applied force and 7 Hz frequency. The flexibility endurance was confirmed from 3000 bending cycles. PENG attached to knee delivered 1 and 2.3 V on bending to 45 and 90°, respectively. After electrical poling, the PENG was subjected to a 20 N tapping force that yielded a piezopotential of 31 V. To the best of our knowledge, this is the first time piezoelectricity was obtained using an ST/PVDF composite via mechanical energy harvesting. The flexible PENG film deposited by cold-spraying shows good potential for wearable self-powered devices.

Flexible piezoelectric energy-harvesting nanogenerator using supersonically sprayed polyvinylidene fluoride and iron oxide nanocubes

Soft wearable electronics are being applied as state-of-the-art self-powered devices based on piezoelectric nanogenerators (PENGs), which provide flexible energy harvesters and sustainable energy generators. We introduce a composite of poly(vinylidene fluoride) (PVDF) and Fe2O3 nanocube fillers coated via supersonic cold spraying to obtain substrate-free and flexible films for PENGs. The hydrothermally synthesized Fe2O3 nanocubes induce shear stress between Fe2O3 and PVDF during supersonic spraying. An optimized sample having 0.77 g Fe2O3 in 1 g PVDF produces a piezopotential of 25.6 V and a short-circuit current of 70 μA. In addition, a maximum power density of 44.4 μW·cm−2 is achieved at a load resistance of 1 MΩ. Tapping and bending tests for 1800 s confirm the consistent generation of piezopotentials of 25.6 V and 1.5 V, respectively. The developed Fe2O3/PVDF PENG can power several light-emitting diodes, thus showing promise as a device for sustainable power supply.

Thermal energy management using supersonically sprayed copper pyramids decorated with zinc oxide nanowires for surface cooling

Miniaturized microelectronics or small modular reactors (SMRs) simultaneously undergo an increase in heat flux and a decrease in size with the enhancement of device functionalities. Therefore, efficient convection cooling is required to prevent the malfunctioning of electronic devices or small nuclear reactors. Herein, mesh-patterned copper pyramids were fabricated via supersonic spraying for surface cooling applications. Zinc oxide nanowires (ZnO NWs) were patterned on top of the copper pyramids to produce a highly efficient cooling system for a high-heat-flux surface by increasing the overall surface area of the pyramids. In addition, ZnO NW decoration imparted superhydrophilicity to the surface with firm anchoring and spreading of impacting spray liquid drops until complete evaporation. The effects of macroscale pyramid mesh resolution and introduction of ZnO NWs on the spray cooling efficiency were quantified and compared. Herein, the pyramids with coarse resolution and ZnO NWs yielded the highest heat flux during the drop impact heat transfer process and the lowest surface temperature under air and spray cooling conditions owing to the maximized surface area. The use of the pyramids and introduction of ZnO NWs increased the Leidenfrost temperature from 140 to 190 °C, thereby expanding the range of the evaporation cooling regime.

Uniformly distributed FeVO4 nanocuboids on exfoliated rGO facilitated by supersonic spraying for wearable supercapacitors

High-energy–density supercapacitors exhibiting high power density and long-term stability are essential devices for energy storage applications, such as wearable electronics. In this study, we utilized supersonic spray deposition to exfoliate reduced graphene oxide (rGO). Additionally, a solvothermal process was employed to engineer the nanostructure of iron/vanadium oxides. Consequently, the resulting multivalent iron/vanadium oxide and rGO composites exhibited remarkably high energy densities. Three major parametric studies were conducted to investigate the electrochemical properties of iron oxide (FO), vanadium oxide (VO), and iron/vanadium oxide (FVO) composites with rGO. FVO/rGO emerged as the most promising sample, exhibiting an areal capacitance of 1240 mF·cm−2 at a current density of 2 mA·cm−2, as well as achieving a 90 % capacitance retention even after 8000 galvanostatic charge–discharge cycles. Furthermore, this sample delivered an energy density of 0.17 mWh·cm−2 at a power density of 4 mW·cm−2.

Supersonic spray derived Cu–Co oxide coating on SUS441 to protect the metallic interconnect and to increase stability of SOFC cathode

The interconnects for solid oxide fuel cells (SOFCs) are usually ferritic stainless steels such as SUS441. These steels have issues of oxidation and Cr diffusion under the operational high temperatures, which can cause serious deterioration of the cathode performance. In order to improve the electrode stability and the oxidation resistivity, this work deposits Cu–Co oxide coating on SUS441 interconnects via room-temperature supersonic spray using fine CuCo2O4 spinel-based oxide powders synthesized via a combustion process. The coating can significantly inhibit the growth of chromium oxide scale on the steel surface and increase the interconnect conductivity by a factor of 4.4 in 200-hr oxidation test in air. The coating effectively prevents Cr diffusion to the cell composed of La0·6Sr0·4FeO3-δ electrode and La0·8Sr0.2Ga0.8Mg0·2O3-δ electrolyte. As a result, the coating substantially increases the cathode performance by reducing the interfacial polarization resistance and improving the stability in 100-hr test at 800 °C. This study demonstrates that this high-performance protective Cu–Co oxide coating has a promising application prospect for SOFC interconnects.

Beta-phase transformation of polyvinylidene fluoride with supersonically sprayed ZnSnO3 cuboids for flexible piezoelectric nanogenerators

Flexible self-powered electromechanical devices, such as piezoelectric nanogenerators (PENGs), which are used in wearable and implantable devices, are emerging as state-of-the-art clean energy sources. In this study, a scalable supersonic spraying technique was used to prepare flexible piezocomposite films of polyvinylidene fluoride (PVDF) and hydrothermally synthesized ZnSnO3 (ZSO) cubes for PENGs. Raman spectra confirmed that the transformation of the α-phase of PVDF to its β-phase was induced by the shear stress generated between the ZSO particles and PVDF polymer during supersonic spraying. The optimized sample comprising 0.43 g of ZSO cubes and 1 g of PVDF produced a maximum piezopotential of 41.5 V and a short-circuit current, Isc, of 52.5 μA. A maximum power density of 50.6 μW cm−2 was obtained at a loading resistance of 0.4 MΩ, which matched the impedance of the PENG. Long-term tapping and bending cycles of Ntap = 4200 and Nbend = 600 yielded piezopotentials of 40.5 and 1.7 V, respectively. In addition, electrical poling for 2 h increased the piezopotential to 52 V owing to the alignment of the ferroelectric dipoles in the PVDF.

Nanotextured surfaces with iron oxide and titania for antibacterial and water purification applications via supersonic spraying

Microbial infections pose a significant threat to public health worldwide. Antibacterial treatments are required to prevent bacterial contamination and protect public health. Herein we supersonically sprayed iron and titania NPs which are nontoxic earth-abundant and low-cost antibacterial materials to fabricate Fe2O3/TiO2-based antibacterial hybrid films capable of inhibiting E. coli by up to 100% upon ultraviolet (UV) light irradiation. The supersonically sprayed iron and titania NPs were annealed to prepare Fe2O3/TiO2-based metal oxide nanosheets. The photomobilized electrons and holes generated superoxide anions and hydroxyl radicals respectively via reduction and oxidation. The bare Fe2O3-based and hybrid Fe2O3/TiO2-based films were photoactivated via visible and UV lights and exhibited E. coli inhibition rates of 42.1% and 99.9% respectively. In addition the hybrid Fe2O3/TiO2-based films were superhydrophilic which promoted the strong adhesion of bacteria-contaminated aerosols between the surrounding atmosphere and films. The water-purification capability of the films was confirmed by the efficient photodegradation of a methylene blue solution upon UV irradiation.

Scalable, flexible BaTiO3/PVDF piezocomposites prepared via supersonic spraying for use in energy harvesting and integrated energy storage devices

Flexible piezoelectric nanogenerators (PENGs) are emerging as sustainable power sources for self-charging wearable electronic devices owing to their ability to harvest ambient mechanical energy. The use of piezopolymer polyvinylidene fluoride (PVDF) and piezoceramic barium titanate (BaTiO3) as flexible composite materials for PENGs deposited using the supersonic cold-spraying technique was investigated in this study. The PENG with an optimized concentration of BaTiO3 to PVDF generated a piezoelectric voltage of 11.5 V when subjected to a tapping force of 5 N for 15,000 cycles. Scanning electron microscopy images captured after cycling confirm the robustness of the BaTiO3 and PVDF composite films. A maximum power of 28.7 μW was achieved at an impedance-matching resistance of 0.7 MΩ. A flexible-PENG bending test of 3000 cycles with a bending radius of 0.8 cm confirmed the durability when an optimal PVDF matrix accommodated well-dispersed BaTiO3 particles. Furthermore, the ferroelectric characteristics of BaTiO3 and PVDF were activated by electrical poling for 14 h, thereby increasing an open circuit voltage to 37.5 V, indicating the possibility of a 3.3-times enhancement after poling.

Supersonically Sprayed Flexible ZnO/PVDF Composite Films with Enhanced Piezoelectricity for Energy Harvesting and Storage

A flexible piezoelectric nanogenerator (PENG) was developed to convert ambient mechanical energy into electrical energy. Highly crystalline template-free zinc oxide (ZnO) microrods were prepared using a wet chemical method at a low temperature. As-synthesized ZnO microrods were blended with polyvinylidene fluoride (PVDF) to prepare a piezoelectric composite film using the supersonic spraying method. A PENG electrode comprising ZnO microrods (0.5 g) produced 15.2 V under a tapping force of 20 N at 5 Hz. In addition, an output current of 32 μA was produced with a maximum power density of 12.5 μW cm–2. The output voltage considering various body movements was investigated to demonstrate the flexibility and durability of the proposed PENG. Furthermore, the supercapacitive properties of ZnO/reduced graphene oxide were studied.

Wearable heater composites comprising traditional Hanji cellulose fibers coated with graphene, silver nanowires, and PEDOT:PSS via scalable supersonic spraying

Traditional Korean Hanji paper and cotton fabric were introduced as flexible substrates in the fabrication of graphene-coated heaters. Silver nanowires and PEDOT:PSS were added to increase the electrical conductivity of the heaters, thereby enhancing their heating performance. The optimal concentrations of silver nanowires and PEDOT:PSS with respect to that of graphene were identified. These active materials were deposited on flexible Hanji/cotton and non-flexible alumina substrates using supersonic spraying. The proposed Hanji- and cotton-based heaters were light, wearable, stretchable, skin-friendly, and biodegradable. The unyielding alumina-based heater exhibited the highest heating temperature of 275 °C at 13 V. Wearable heater bendability and stretchability were tested considering multiple bending and stretching cycles. Moreover, water boiling and fabric drying were successfully performed using the alumina-based heater. The supersonic spraying deposition technique was used to produce writable and patternable heaters.

Water-repelling, vapor-resisting, self-cleaning, oil–water-separating, water-purifying, antibacterial Hanji cellulose papers coated with Teflon and ZnO particles via supersonic spraying

Cellulose-based Korean mulberry paper, called Hanji, has been used as a functional material in heaters, supercapacitors, sensors, and light-emitting diodes because of its low weight, high mechanical strength, antibacterial activity, and eco-friendliness. Imparting water resistance property to these functional papers is critical to protect them against potential moisture-associated damage and to ensure their longevity. This study applied supersonic spraying technique to deposit superhydrophobic Teflon and antibacterial ZnO particles on Hanji. The results show that functionalized Hanji deposited with Teflon/ZnO exhibited water-repelling, anti-fogging, and antibacterial properties. Furthermore, the photoinduced water purification and self-cleaning features of functionalized Hanji has been demonstrated. Hanji enabled the passage of purple-colored hexane; however, blue-colored water could not permeate the Hanji filter, demonstrating the oil–water separation capability of Hanji.

A Study on Converging-Diverging Nozzle Design for Supersonic Spraying of Liquid Droplets Toward Nanocoating Applications

Abstract Supersonic cold spray (CS) of functional nanomaterials from atomized droplets has attracted significant attention in advanced thin-film coating as it enables particle deposition with high-adhesion strength. In CS, optimum design of the supersonic nozzle (i.e., converging-diverging nozzle) is essential for accelerating particles to desired velocities. However, research on the nozzle design for supersonically spraying of “liquid droplets” for nanocoating applications is limited. To this end, we investigate the effect of nozzle geometrical parameters, including throat diameter, exit diameter, and divergent length on droplets impact velocity by numerical modeling and experimental validation, followed by a case study on nanocoating. The discrete-phase modeling was employed to study droplets’ flow behavior in continuous gas flow for various nozzle geometries. The results reveal that the nozzle expansion ratio, defined as a function of throat and exit diameters, has a significant influence on droplet velocity, followed by divergent length. Noteworthy, to correctly accelerate “low-inertia liquid microdroplets,” it was found that the optimum nozzle expansion ratio for axisymmetric convergent-divergent nozzles should be in a range of 1.5–2.5, which is different and way smaller than the recommended expansion ratio (i.e., 5–9) for CS of conventional micron-scale “metal” powders. Based on the simulation results, an optimum design of supersonic nozzle is established and prototyped for the experimental studies. Particle image velocimetry (PIV) was used to experimentally investigate the spray flow field and to validate the numerical modeling results. Moreover, coating experiments using the optimized nozzle confirmed the effective supersonic spraying of droplets containing nanoparticles, thereby showing the potential for advanced nanocoating applications.

Eco-friendly cellulose wearable heaters using Korean traditional Han paper coated with graphene nanosheets via binder-free supersonic spraying

Transparent and nontransparent exoskeleton wearable heaters are used in automobile and aircraft deicing, oil-pipeline defrosting, smart windows, underwater protection clothing, winter sportswear, bioelectronics, personal healthcare, athletic rehabilitation, and thermotherapy applications. In this study, we introduce Korean traditional Han paper (or Hanji), which comprises eco-friendly cellulose fibers from the mulberry bark, as a substrate for nontransparent wearable heaters. Hanji consists of cellulose fibers and is highly flexible, making it suitable for low-cost roll-to-roll scalable production. Graphene flakes are readily and firmly embedded inside the fibrous structure of Hanji by the catastrophic impact inflicted by supersonic spraying. Additionally, Hanji can withstand temperatures of up to 100 °C before suffering thermal damage. The heater with the thicker graphene layer had the lowest electrical resistance and exhibited the highest heating temperature at a constant voltage level. Graphene flakes are firmly held inside the fibrous structure of Hanji, securing the material's mechanical durability. Additionally, tests at various bending radii were conducted to demonstrate the mechanical strength of the Hanji graphene heater. Graphene flakes deposited on an unyielding alumina substrate withstood temperatures of up to 280 °C, thereby facilitating the use of the substrate in high-temperature applications. Graphene-coated textiles were heated and stretched up to 50%, thus demonstrating the application of such materials in human-body thermotherapy.

Supersonically sprayed PVDF and ZnO flowers with built-in nanocuboids for wearable piezoelectric nanogenerators

Healthcare implant devices that can internally generate a flow of electrical charge driven by mechanical stimuli are in demand. Such self-powered electromechanical devices are known as piezoelectric nanogenerators (PENGs). In this study, a piezo-ceramic element of hydrothermally synthesized ZnO flowers comprising built-in nanocuboids was supersonically sprayed with piezo-polymer polyvinylidene fluoride (PVDF) to fabricate ZnO-embedded PVDF films for flexible PENG devices. In the presence of ZnO, the catastrophic supersonic impact and shear flow transformed the nonpolar α-phase of PVDF into the polar β-phase. The combination of ZnO flowers with built-in nanocuboids and β-phase-rich PVDF can help enhance generated charges at interfacial sites under an applied force. The supersonically sprayed PVDF/ZnO composite exhibited a 32% increase in the β-phase compared to that exhibited by pure PVDF prior to supersonic coating. The effective piezoelectric coefficient values (d33*) of the pure PVDF and PVDF/ZnO composite films were 43 and 150 pm·V‐1, respectively; the corresponding open-circuit voltages were 1.2 and 25.5 V, respectively. These significant differences confirm the pivotal role of ZnO in increasing the β-phase within PVDF during supersonic spraying. The form of the externally applied force and frequency were varied to evaluate the electromechanical performance of PVDF/ZnO. The energy harvesting capability of the composite was demonstrated using 33 light-emitting diodes.

Investigation of CuxMn3-xO4 coatings for solid oxide fuel cell interconnect applications

In order to investigate the performance of Cu–Mn spinel coatings used for solid oxide fuel cell interconnect, a series of CuxMn3-xO4 (x = 0.6, 0.8, 1.0, 1.1, 1.2, and 1.3) coatings are prepared using supersonic spraying via subsequent sintering. The chemical composition and distribution, lattice structures, morphology, and electrical properties are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and area-specific resistance (ASR) measurements. The experimental results show that with the increase of Cu concentration in the coatings, the crystalline structure gradually changes from inverse spinel into normal spinel, especially when 0.6 ≤ x ≤ 1.0. An improvement in electrical conductivity accompanies the crystalline structural transformation. The coatings show high electrical conductivity when 1.0 ≤ x ≤ 1.3, especially from 600 to 800 °C. However, the scale (mainly Cr2O3) is reactive to the CuxMn3-xO4 coatings (especially when 1.1 ≤ x ≤ 1.3) at elevated temperatures. During the long-term experiment, the reaction corrodes the coatings, consumes the materials in coatings and scale, and forms new phases (mainly (Cu,Mn,Cr)3O4 and (Cr,Mn)3O4). This phenomenon (Cr-corrosion) aggravates the Cr diffusion, causes a quick increase of ASR, and weakens the oxidation resistance. The adverse effects of Cr-corrosion can be alleviated by appropriately lowering the operating temperature. Among the coatings, Cu1.0Mn2.0O4 exhibited good electrical conductivity and soundness against the Cr-corrosion and can be considered a competitive candidate for SOFC applications.

Drop impact phenomena and spray cooling on hot nanotextured surfaces of various architectures and dynamic wettability

Spray cooling has been used to quench metal slabs during casting, cool nuclear reactors, suppress accidental fires, and remove heat from high-power density electronics. In particular, the miniaturization of electronic devices inevitably results in an increased power density or heat flux on the microelectronics surfaces and poses a threat of a thermal shutdown of such devices when cooling is insufficient. Surface nanotexturing effectively augments additional liquid-to-substrate surface area, thereby increasing cooling capability, as well as an effective heat transfer coefficient. In spray cooling, surface dynamic wettability also affects drop impact dynamics and subsequent coolant evaporation on a hot surface. Herein, we introduced various nanotextured surfaces and affected dynamic wettability using the so-called thorny-devil nanofibers, nickel nanocones, Teflon and titania nanoparticles, and zinc nanowires. The effect of these different nanoscale architectures on drop impact phenomena and subsequent evaporative cooling was investigated. These nanotextured surfaces were fabricated using various deposition methods, including electrospinning, electroplating, supersonic spraying, aerosol deposition, and chemical bath deposition. We found that the surface with greater dynamic wettability related to the hydrodynamic focusing considerably improved the heat removal capability by furthering the Leidenfrost limit and facilitating drop spreading. In particular, the thorny-devil nanofiber surface yielded the highest heat flux at all ranges of the Reynolds and Weber numbers. Spray cooling on a model electronic kit also confirmed that the thorny-devil nanofibers were most effective in cooling the surface of the model kit during multiple cycles of water spraying.

CuxCo3-xO4-δ (0≤x≤1) coatings for solid oxide fuel cell interconnect applications

In order to obtain the solid oxide fuel cell (SOFC) interconnect coatings with high electrical conductivity, satisfactory protectiveness, and well-fitting thermal expansion, a series of CuxCo3-xO4-δ (x = 0, 0.5, 0.8, and 1.0) coatings are prepared by supersonic spraying via subsequent sintering. The chemical composition, lattice and morphological structures, electrical properties, and thermal expansion are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), area-specific resistance (ASR), and coefficient of thermal expansion (CTE) measurements. The experimental results show that the formation of CuCo2O4 is a reversible and incomplete reaction at the elevated temperature, and the coexistence of CuO, Co3O4, and CuCo2O4 is inevitable in the coatings. The concentration of the chemicals mentioned above is highly related to the coatings’ Cu:Co molar ratio. The correlation between the chemical composition and the properties is comprehensively studied in this research. The CuxCo3-xO4-δ coatings exhibit good electrical conductivity when 0 ≤ x ≤ 0.8, satisfactory protectiveness when 0.5 ≤ x ≤ 1.0, and fitting CTE with remarkable robustness through the quick heating-cooling cycles when 0.8 ≤ x ≤ 1.0. In general, Cu0.8Co2.2O4-δ can be an appropriate candidate to meet the advancing interconnect coating demands with high electrical conductivity, satisfactory protectiveness, and well-fitting thermal expansion properties.

Pool boiling performance of TiO2 superhydrophilic and Teflon superhydrophobic surfaces on evenly deposited copper frustums

The miniaturization of electronic devices with ever-increasing functionalities inevitably results in greater thermal load on the devices. Hence, pool boiling, which utilizes the powerful latent heat of vaporization, is introduced as an effective method to manage severe thermal loads on miniaturized electronics. Hydrophobic surfaces tend to augment sufficient nucleation sites via roughening or low surface energy, while hydrophilic surfaces are prone to ample liquid supply, thus facilitating rapid bubble release and preventing surface dry-out. Herein, we compared the heat removal performance of TiO2-coated superhydrophilic and Teflon-coated superhydrophobic surfaces fabricated by aerosol deposition and supersonic spraying, respectively. TiO2 and Teflon particles were deposited on evenly patterned frustums. The resolution of the frustum is categorized as no-frustum, coarse, medium, or fine. We found that the surface wettability had little effect on the critical heat flux (CHF) for the no-frustum and fine cases. However, the CHF and effective heat transfer coefficient (heff) of the superhydrophilic surface increased considerably in the medium case. For the superhydrophobic surface, the presence of frustum deteriorated the pool boiling performance. Frustum texturing enhanced the pool boiling performance by increasing the number of nucleation sites and pathways of fresh liquid supply for the bare and superhydrophilic surfaces, but not for the superhydrophobic surface.

Functional-gradient coatings of the HfB<sub>2</sub>–Si<sub>3</sub>N<sub>4</sub> system with high wear resistance obtained by supersonic cold gas-dynamic spraying

The results of comprehensive studies of obtaining functionally graded coatings based on HfB2– Si3N4–Zr compositions using the technology of supersonic cold gas-dynamic spraying are presented. Data are given on the measurement of adhesive strength (up to 62 MPa), microhardness (up to 42 GPa) and wear resis- tance (up to 1.2·10–9 mm/km) of the obtained coatings.