Cobalt Coatings Research Articles

Multiscale textured solar absorber coatings for next-generation concentrating solar power

A high-temperature stable solar absorber is crucial for next-generation (Gen3) concentrating solar power (CSP) plants, to enable high temperature operation, maximize power generation efficiency, and thereby reduce the levelized cost of energy. This study presents novel, fractal-textured solar absorber coatings whose multiscale feature scales effectively match the visible region of the solar spectrum, leading to superb absorptive properties. Single and bimetallic oxide coatings of copper, cobalt and manganese were prepared on Inconel 625 substrates using electrodeposition. The effect of electrodeposition parameters and annealing temperature are systematically studied to optimize the morphology and properties of the oxide coatings. Multiscale textured bimetallic coatings of copper manganese oxide and copper cobalt oxide demonstrate a superior absorptance of 0.985, a remarkably low emittance <0.45 and an exceptional optical efficiency of ∼96 % under Gen3 CSP operating conditions, surpassing previously reported values in the literature by about 5 %. Durability tests confirmed the coatings’ steadfast endurance of mechanical and environmental stress, making them suitable for long-term application in harsh CSP environments.

Influence of Cobalt and Cobalt–Manganese Oxide Coating Thickness Deposited by DLI-MOCVD as a Barrier Against Cr Diffusion for SOC Interconnect

The influence of cobalt and cobalt–manganese oxide coating thickness on its ability to be a good diffusion barrier against Cr outward diffusion was investigated for stainless steel interconnects (AISI 441) of a solid oxide cell (SOC). The coatings were all synthesized using a DLI-MOCVD (Direct Liquid Injection-Metal Oxide Chemical Vapor Deposition) hot wall reactor. The study shows that a minimum cobalt oxide thickness of 300 nm was needed to be a good diffusion barrier against Cr for the 500-h exposure test. This observation was linked to the Mn concentration reached in the cobalt spinel during exposure. Indeed, during exposure at high temperature, Mn diffused from the substrate into the cobalt coating and transformed cobalt spinel into Co-Mn spinel. Whereas pure cobalt spinel was a good Cr diffusion barrier, cobalt-manganese spinel, Co3-xMnxO4, was not when x > 2. The thickness of the cobalt coatings must be chosen so that the Mn quantity coming into it from diffusion from the substrate does not degrade the protectiveness of the coating.

Using anodic oxidation for boosting supercapacitive performance of thermally-oxidized cobalt coatings with various morphologies

Metal oxide electrodes for supercapacitors are commonly synthesized through the hydrothermal method. Despite the simplicity and cost-effectiveness of electrodeposition for producing electrode materials, there is a scarcity of literature on electrodeposited electrodes. Previous studies have utilized nitrate-based solutions and subsequent heat-treatment to fabricate these materials without additional treatments to enhance their performance. This research explores the creation of cobalt coatings with varying morphologies (pyramidal, ridge-shaped, powdery, and rough nodular) using electrodeposition from sulfate-based solutions by adjusting deposition parameters. The cobalt coatings were then heat-treated at 550˚C for 3 h to convert them to cobalt oxide, a promising material for supercapacitor electrodes. The study investigates the impact of initial morphology on the structure, phases formed, and supercapacitive properties of the heat-treated coatings. Analysis of XRD and FTIR data indicated that the primary phase post-heat treatment was Co3O4, alongside some CoO. Cyclic voltammetry (CV) measurements in 1 M KOH solution revealed that the powdery coating exhibited the highest specific capacitance of 796±21 mF cm−2 (∼110 F g−1) at a scanning rate of 2 mV s−1, surpassing the heat-treated pyramidal coating by approximately tenfold. These CV findings were corroborated by galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) analyses. Furthermore, the heat-treated coatings underwent anodic oxidation in a 3 M KCl solution for 5 minutes to assess the impact of this lesser-known process on their capacitive behavior. Following anodic oxidation, the ridge-shaped and pyramidal coatings displayed significantly enhanced specific capacitance due to the formation of fine pores and surface modifications. Specifically, the specific capacitance of the ridge-shaped coating surged from 103±4 mF cm−2 (∼11 F g−1) to 1832±64 mF cm−2 (∼201 F g−1) at a scanning rate of 2 mV s−1 after anodic oxidation. Although the rough nodular coating also experienced an increase in specific capacitance, the morphology and electrochemical characteristics of the powdery coating remained relatively stable throughout the study.

A Comparative Study of the Life Cycle Inventory of Thermally Sprayed WC-12Co Coatings

In this research, a life cycle inventory (LCI) is developed for tungsten carbide–cobalt (WC-Co) coatings deposited via atmospheric plasma spray (APS), high-velocity oxy-fuel (HVOF), and cold gas spray (CGS) techniques. For the APS process, a mixture of Ar/H2 was used, while the HVOF process was fueled by H2. The carrier gas for CGS was N2. This study aims to determine and quantify the inputs (consumption of inputs and materials) and outputs (emissions to air, soil, water, and waste generation) that could be used in the life cycle analysis (LCA) of these processes. The dataset produced will allow users to estimate the environmental impacts of these processes using WC-Co feedstock powder. To obtain a complete and detailed LCI, measurements of electrical energy, gas, WC-CO powder, and alumina powder consumption were performed (the use of alumina was for sandblasting). Furthermore, emissions like carbon dioxide (CO2), carbon monoxide (CO), and noise were also measured. This practice allowed us to determine the input/output process quantities. For the first time, it was possible to obtain LCI data for the APS, HVOF, and CGS deposition processes using WC-12Co as a feedstock powder, allowing access to the LCI data to a broader audience. Comparisons were made between APS, HVOF, and CGS processes in terms of consumption and emissions. It was determined that the APS process consumes more electrical energy and that its deposition efficiency is higher than the other processes, while the HVOF process consumes a large amount of H2, which makes the process costlier. CGS has comparatively low electricity consumption, high N2 consumption, and low deposition efficiency. The APS, HVOF, and CGS processes analyzed in this study do not emit CO, and CO2 emissions are negligible.

Stress-induced, debris-modulated friction and wear resistance performance of nanostructured Ni–Co coatings

Owing to their HCP structure and inherent resistance to deformation, Cobalt-containing alloys are often used for low-friction and wear-resistant purposes. Here, the tribological performance of nanostructured Nickel–Cobalt coatings with 0–83 wt% Co was investigated. Three Co-rich coatings with similar microhardness and grain sizes showed different friction and wear behaviors that cannot be solely attributed to the HCP phase fraction. The coating with the highest Co content of 83 wt% achieved the lowest wear rate. However, the lowest surface friction was observed in Ni-76 wt% Co with a large amount of wear debris covering the contact surface of its counterpart. Nevertheless, these debris led to micro-cutting of the coating and a high wear rate. Detailed surface investigation of these coatings and their counterparts revealed a significant difference in material transfer, distribution of wear products, and wear mechanisms. Our analysis showed that the tribological performance of Ni–Co coatings can be dominated by surface-related features (such as surface oxide integrity, tribofilm, and wear debris) and lattice internal stress over the underlying phase fractions.

Synthesis and Structure of the Nanosized Cobalt Coatings on Porous Aluminum Oxide

The results of studies of the morphology and chemical structure of cobalt coatings deposited by magnetron sputtering on nanostructured surfaces of porous alumina with different morphologies are presented. The morphology of porous alumina was specified by the anodization voltage in solutions of sulfuric (25 V) and oxalic (40 and 120 V) acids. Using scanning electron and atomic force microscopy, it has been shown that the coatings have morphological features, which are hexagonally arranged nanoparticles formed at the boundaries between pores. With an increase in the size of nanopores on the surface of the substrates, the size and shape of the morphological features of the deposited coatings change. According to X-ray absorption fine structure spectroscopy and fine structure spectroscopy of the near region of the X-ray absorption edge, there are changes in the local atomic structure of cobalt, in particular, cobalt in a coating sample deposited on the surface of porous alumina obtained by anodizing at a voltage of 25 V in sulfuric acid, oxidized more strongly, which is associated with greater chemical activity due to the smaller sizes of the nanoparticles that make up the coating. The results obtained will allow in the future to make a directed change in the formation of structure-sensitive properties, such as chemical and electrochemical activity, magnetic sensitivity, of the resulting coatings.

An improvement in aluminium composites interface strength and microhardness through electroless cobalt coatings on tungsten carbide

Aluminium tungsten carbide (Al-WC) composites are extensively employed in defence and automotive industries, have been given an attempt to increase their interfacial strength. The improvement of interfacial strength is investigated by powder metallurgy process. It was calculated that the electroless cobalt coated WC reinforcement's ultimate breaking load had risen by 45% compared to uncoated reinforcement. The presence of cobalt in the aluminium matrix was confirmed by powder XRD and SEM examinations. Thus, the produced composites can be employed for heavy machinery as an alternative to monolithic alloys because of improved interfacial strength and micro hardness.

Deposition current density-induced grain boundary engineering of electrodeposited cobalt coatings for enhanced electrochemical stability

ABSTRACT Cobalt coatings were electrodeposited at different deposition current densities (10 mA·cm−2, 20 mA·cm−2, 30 mA·cm−2, 40 mA·cm−2, 60 mA·cm−2) over mild steel substrate. The coating deposited at 30 mA·cm−2 showed the highest corrosion resistance (Rp = 7515Ω·cm2) due to a higher fraction of Low energy grain boundary constitution (i.e. coincidence site lattices (CSLs) and low angle grain boundaries (LAGB)) and exhibited higher fraction of stabler Co3O4 passive oxide layer. The coatings electrodeposited at 60 mAcm−2 exhibited lower corrosion resistance (Rp = 1304 Ω·cm2) due to a higher fraction of high-angle grain boundaries and a higher fraction of relatively lesser stable Co(OH)2.

Synthesis of electrodeposited Co–P–ZrO2–CeO2 nanocomposite coating: Effect of heat treatment on corrosion and mechanical properties

Electrodeposited cobalt coatings have been considered a suitable replacement for hard chromium coatings due to their promising properties. In this research, electrochemical methods through the direct current technique have been applied to synthesize a novel Co–P–ZrO2–CeO2 nanocomposite coating. The addition of different phosphorous contents as a determinant of the crystalline or amorphous structure was investigated using X-ray diffraction (XRD). The needle-like or cauliflower morphologies and related elemental compositions were surveyed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. The XRD, microhardness, wear, and corrosion resistance tests were conducted on heat-treated samples. The results illustrate that heat treatment significantly increases the microhardness of the amorphous nanocomposite layer (up to 1323 HV0.1). Additionally, it causes the best wear behavior for the nanocrystalline Co–P–ZrO2–CeO2 (0.2), while leading to a lower wear resistance for the amorphous coatings (0.65). Furthermore, applying heat treatment diminishes the corrosion behavior of the coating. Tafel polarization and electrochemical impedance spectroscopy (EIS) tests reveal that the best corrosion resistance has been achieved for an amorphous nanocomposite coating 11929 Ω cm2. These findings demonstrate that this coating has desirable properties for industrial applications.

On the Use of Surfactant Polarity for Grain Boundary Engineering in Electrodeposited Cobalt Coatings and Its Direct Effect on the Coating Corrosion Behavior

On the Use of Surfactant Polarity for Grain Boundary Engineering in Electrodeposited Cobalt Coatings and Its Direct Effect on the Coating Corrosion Behavior

Comparison of Superhydrophobicity, Anti-Corrosion, Anti-Icing, and Self-Cleaning Properties of Nickel and Cobalt Coatings Fabricated by one-Step Electrodeposition

Comparison of Superhydrophobicity, Anti-Corrosion, Anti-Icing, and Self-Cleaning Properties of Nickel and Cobalt Coatings Fabricated by one-Step Electrodeposition

Effect of electrolysis parameters on the functional properties of composite electrolytic coatings

Problem. The functional properties of composite electrolytic coatings Co-Mo-WОх, Co-W-ZrО2, Co-Mo-ZrО2, besieged in galvanostatic mode from pyrophosphate-citrate electrolytes are discussed. The effect of the temperature and acidity of the electrolyte on the microstinity of coatings has been proved. It was established that the content of refractory metals does not affect the microhardness of cobalt coatings with such metals, however, dependence on the conditions of the electrical sanction was detected. Goal. The goal is investigation of the effect of electrolysis parameters on the qualitative composition and microhardness of cobalt-based composite coatings with heavy metals. Methodology. The electrical equipment was made at a unipolar current when varying the density of current and temperature. The morphology of the surface was investigated using the Zeiss Evo 40xvp. The study of the phase composition of the coatings was carried out using X-ray analysis using the Siemens D500 powder diffractometer in the emitting of copper with graphite monochrome. The micro-hardness of composite coatings Cо-Mo-WOx, Co-Mo-ZrO2 and Co-W-ZrO2, as well as substrate material was determined as 0.2 kg and an exposure time as 10 s. Results. The increase in the micro-hardness of the covers relative to the ranging components is proven, with the highest indicator of the Cо-Mо-WOх systems (1100kg/mm2), and the micro-affirmation of the Cо-Mо-ZrО2 and Cо-W-ZrО2 is up to 550 kg/mm2. Originality. The effect of electrolysis parameters on the functional properties has been established, in frequency the micro-hardness of composite coatings on the mock-up of cobalt will allow the sphere of use of such coatings. The connection between the composition and morphology of cobalt covers and their physico-mechanical and physical and chemical properties is experimentally established. Based on the studies, it was found that the optimal for the formation of composite electrolytic coatings with cobalt alloys is the span pH = 8–9. Practical value. The compositional coatings of the Cо-Mо-WOх with the overall content of tight components of 25–34 mass% allow to recommend them as wear-resistant coatings for applying parts to products that work in aggressive media at high temperatures.

Comparison of the Activity of 3D Binary or Ternary Cobalt Coatings for Hydrogen and Oxygen Evolution Reactions

In this study, cobalt-nickel (Co-Ni), cobalt-iron (Co-Fe), cobalt-iron-manganese (Co-Fe-Mn), cobalt-iron-molybdenum (Co-Fe-Mo), and cobalt-zinc (Co-Zn) coatings were studied as catalysts towards the evolution of hydrogen (HER) and oxygen (OER). The binary and ternary Co coatings were deposited on a copper surface using the electroless metal plating technique and morpholine borane (MB) as a reducing agent. The as-deposited Co-Ni, Co-Fe, Co-Fe-Mn, Co-Fe-Mo, and Co-Zn coatings produce compact and crack-free layers with typical globular morphology. It was found that the Co-Fe-Mo coating gives the lowest overpotential of 128.0 mV for the HER and the lowest overpotential of 455 mV for the OER to achieve a current density of 10 mA cm−2. The HER and OER current density values increase 1.4–2.0 times with an increase in temperature from 25 °C to 55 °C using the prepared 3D binary or ternary cobalt coatings for HER and OER. The highest mass electrocatalytic activity of 1.55 mA µg−1 for HER and 2.72 mA µg−1 for OER was achieved on the Co-Fe coating with a metal loading of 28.11 µg cm−2 at 25 °C.

Influence of suppressing additive malachite green on superconformal cobalt electrodeposition

• Adsorption-coordination mechanism was calculated by quantum chemistry to demonstrate the inhibition effect of MG. • Adsorption-transport mechanism was illustrated to explain the bottom-up growth of cobalt under the influence of MG. • The nucleation and growth of cobalt is 3D diffusion-controlled progressive nucleation process. A novel suppressor, malachite green, was used to achieve bottom-up growth of cobalt in this work. Electrostatic potential, HOMO/LUMO of malachite green was calculated to provide an insight into the interaction between malachite green and metal substrate, while charge distribution, AIM (atoms in molecules theory) analysis and IRI (interaction region indicator) analysis were coupled to analyze the interaction between malachite green and cobalt ions. Adsorption-coordination inhibition mechanism was illustrated to explain the inhibition effect of malachite green. Electrochemical analysis was applied to evaluate malachite green. Cyclic voltammetry was used to confirm the inhibition effect of malachite green, while EQCM analysis demonstrates that the current efficiency was lowered by MG. The nucleation and growth of cobalt is 3D diffusion-controlled progressive nucleation growth under the influence of hydrogen evolution reaction and the compact cobalt coatings could be obtained by surface analysis. The effective MG concentration gradient could be formed within blind vias according to current transient analysis so as to develop electroplating rate difference. The bottom-up growth of cobalt within blind vias was achieved by carrying out electroplating test and the adsorption-transport mechanism was proposed to explain the superconformal electrodeposition of cobalt under the influence of MG.

Effect of grain boundary constitution on corrosion behaviour in cobalt-carbon nanotube composite coatings

Corrosion behavior and micro-texture of electrodeposited cobalt coatings containing different volume fractions of carbon nanotubes (CNTs) were investigated and correlated. For lower CNT volume fractions, a compact and smoother coating morphology were observed. The morphology however, became coarser for higher CNT volume fractions. Corrosion properties of the coatings were determined using the electrochemical impedance spectroscopy and Tafel polarization techniques. Pristine cobalt coating showed corrosion potential (Ecorr), corrosion current density (icorr), and polarization resistance (Rp) values of -0.574 V, 21.48µA/cm2 and 2071 ohms.cm2 respectively. With the incorporation of CNTs, the coating corrosion resistance increased up to Co-CNT3 coating (produced by 20mg/L of CNT dispersion). Co-CNT3 coating showed Ecorr, icorr and Rp values of -0.521V, 5.33µA/cm2 and 3525 ohms.cm2 respectively. However, for higher volume fractions of CNTs, the coating corrosion resistance dropped to values lower than pristine cobalt coating. For Co-CNT6 coating (produced from 80 mg/L of CNT dispersion) the Ecorr, icorr and Rp values were -0.581V, 23.45µA/cm2 and 1409 ohms.cm2 respectively. Micro-texture analysis was conducted for pristine Co and Co-CNT3 coatings to investigate the correlation between the observed corrosion behavior and coating micro-texture. Both the coatings showed strong {211¯0} texture along the coating growth direction. When compared to printine Co coating, the Co-CNT3 coating showed lesser fraction of high angle grain boundaries as well as higher fraction of low energy special boundaries like STGBs (32°/ [211¯0], 62°/ [211¯0] angle axis pair) leading to better corrosion resistance performance for Co-CNT3 coatings.

СІНТЕЗ І ФОТОКАТАЛІТИЧНІ ВЛАСТИВОСТІ КОМПОЗИЦІЙНИХ ПОКРИТТІВ НА ОСНОВІ КОБАЛЬТУ З ТУГОПЛАВКИМИ КОМПОНЕНТАМИ

The possibility of electrosynthesis and control of the surface composition and morphology of the electrolytic cobalt coatings with refractory metals by varying the parameters of electrolysis has been proved. It was found that oxygen and carbon are included in the composition of the coatings as well as the main components, thus such systems can be considered as composite. The coatings deposited by pulsed current can be considered as composite materials the oxide phase for which is formed directly in the electrode process as an intermediate of incomplete reduction of tungstates and hydrolysis of zirconium (IV) salts. The topography of the films is distinguished by the presence of elliptical and spherical grains with crystallite sizes of 80 - 180 nm. On the surface of the coatings, there are hills (large grains) with a diameter of 1 - 3 μm. The fractal dimension of the surface is 2.77, which indicates the 3D mechanism of crystal growth during the formation of coatings. In terms of phase composition, composites are predominantly amorphous materials that contain nanocrystalline cobalt and the intermetallic compound Co3W and Zr3Co. The study of the morphology and topography of the composite coatings surface, as well as its quantitative and phase composition, indicates the possibility of photocatalytic activity of the Co-Mo-WOх, Co-Mo-ZrO2 and Co-W-ZrO2 coatings. Investigation of the photodegradation of the azo dye methyl orange found that the efficiency of MO removal from the solution was 24%, 18%, and 10% for 30 min of ultraviolet irradiation in the presence of Co-Mo-WOх, Co-Mo-ZrO2 and Co-W-ZrO2 on composite coatings, respectively. The higher photoactivity of Co-Mo-WOx composite coatings can be explained by the presence of non-stoichiometric molybdenum and tungsten oxides.

INFLUENCE OF CARBON NANOTUBES REINFORCEMENT ON CHARACTERISTICS OF THERMALLY SPRAYED CERAMIC COATINGS

The influence of reinforcement of carbon nanotubes (CNTs) on microstructural features and mechanical properties of thermally sprayed Al2O3–3[Formula: see text]wt.%TiO2and WC–20[Formula: see text]wt.%Co coatings was investigated. Alumina–Titania coatings were deposited by Air Plasma Spraying (APS) and Tungsten Carbide–Cobalt coatings were deposited by High-Velocity Oxy-Fuel (HVOF) spraying process. The coatings obtained with reinforcement of CNTs were characterized to interpret the microstructural changes and also to evaluate the variation in their mechanical properties. The percentage composition of CNTs in both APS and HVOF coatings systems were varied in the order of 2, 4, and 6[Formula: see text]wt.%. It has been found that homogenous dispersion of carbon nanotubes in the coating systems results in increased microhardness and reduced surface roughness. Also, the microstructural features of the coating systems clearly showed that the coatings are denser with fewer pores due to the presence of CNTs.

Evolution of microstructure and mechanical properties of Co-SiC tungsten inert gas cladded coating on 304 stainless steel

In this work, Silicon carbide (SiC) reinforced Cobalt (Co) coatings were produced using tungsten inert gas (TIG) coating technique on AISI 304 stainless steel substrates. The effects of various heat inputs on microstructure, wear resistance, coefficient of friction (COF), and microhardness, of composite coatings were systematically investigated. Results of X-ray diffraction (XRD) showed that the composite coatings were primarily composed of FeSi, CoSi, CoSi2, Fe3C, SiC and Co phases. Analysis of the elements by using energy dispersive X-ray spectroscopy (EDX) confirmed the existence of elements Co, C, Si, Ni, and Fe in the coating. The microstructural analysis was performed using scanning electron microscopy (SEM), micrographs showed that grains changed from an irregular polygonal grain to an elongated dendritic grain depending on heat inputs. Composite coating produced at 528 J/mm heat input shows uniformly distributed fine dendritic grains and produces defect-free coatings. The average maximum microhardness of composite coating was increased from ~374 HV0.1 to ~650 HV0.1, whereas the average microhardness of the 304-steel substrate was ~190 HV0.1. Comparative wear resistance of Co-SiC composite coating was appreciably improved, ranging from ~1.7 to ~6.4 times better than that of the AISI 304 stainless steel substrate. At 528 J/ mm heat input, composite coating exhibits the best tribological properties with reduced COF (~0.40) compared to the substrate.

Scratch Resistance of High Velocity Oxy-Fuel Sprayed WC-20% Co Coatings Reinforced with Carbon Nanotubes

Tungsten Carbide-20 weight % Cobalt (WC-20 wt% Co) coatings were extensively used material to achieve a combination of extreme hardness and excellent strength. Hence, an effort has been made to improve the toughening properties of WC-Co coatings through reinforcement of Carbon Nano-Tubes (CNTs) using High-Velocity Oxy-Fuel (HVOF) spraying process. In this work, 2 wt%, 4 wt%, and 6 wt% of CNTs were blended by the ball milling process with WC-Co powders. These composed powders were deposited by HVOF process on to the plain mild steel substrates. The scratch test analysis on as-sprayed coatings showed that due to the addition of CNTs on WC-Co coatings, the resistance to penetrate the coating surface increased. Also, by varying the percentage of CNTs in the coating system, the pores were reduced. This phenomenon is attributed to the toughening mechanism by forming a CNT bridge which avoids the formation of internal cracks.

COMPOSITION AND SURFACE MORPHOLOGY OF COMPOSITE ELECTROLYTIC COATINGS CO-W-ZRO2

possibility of electrosynthesis and control of the composition and surface morphology of the composite electrolytic coatings of cobalt with refractory metals by varying the pulse current density has been proved. Composites deposited on copper substrate from biligand citrate-pyrophosphate electrolytes at 4 A/dm2 are distinguished by a developed surface and a more uniform distribution of components on the surface, increased tungsten content, almost 5 times higher than coatings deposited at 10 A/dm2, and a half reduction in oxygen percentage (up to 5.5%). This is explained by the inhibition of the hydrogen gas evolution reaction and the participation of hydrogen ad-atoms in the chemical reduction of intermediate tungsten oxides to metal when polarization is interrupted. Coatings obtained using pulsed current can be considered as composites of the composition Co-W-ZrO2, in which the oxide phase is formed directly in the electrode process as an intermediate for the incomplete reduction of tungstates. The topography of the films is characterized by the presence of grains of elliptical and spherical shape with crystallite sizes of 80 – 180 nm. On the main surface there are protrusions (large grains) with a diameter of 1 – 3 microns. The fractal dimension of the surface is 2.77, which indicates the 3D crystal growth mechanism during coating formation. According to the surface roughness parameters Ra and Rq, coatings belong to the 9th roughness class. By phase composition, composites are predominantly amorphous materials, which include nanocrystalline cobalt and intermetallic compounds Co3W and Zr3Co. Due to the quantitative and phase composition, surface morphology and fractality, the microhardness and corrosion resistance of Co-W-ZrO2 systems deposited at a current density of 4 А/dm2 are 20% higher than the coatings obtained at 10 A/dm2, and 3 times higher than the corresponding characteristics of the substrate.