Electric Arc Spraying Research Articles

Microhardness and Elastic Properties Evaluation of WC-TiC Coatings Obtained by Arc Spraying Process

Fulfilling the basic role of hard thermal sprayied coatings is closely related to the value of its microhardness. The quality of such a layer depends on several variables, the main categories being: spray method (flame spray, electric arc, plasma spray, cold spray, etc.), spray parameters (spray distance, voltage and intensity, working atmosphere, direction of the spray jet, etc.) and the materials used (chemical composition of the coating materials, quality and texture of the substrate). In this study, the microhardness, elastic properties and cohesion of a coating made of hard cored wire (Praxair – Tafa) by electric arc spraying process on a low alloy steel substrate, were analyzed. The cored wire has as main hard elements WC (about 26%) and TiC (about 6%), the rest of the chemical elements present being: Cr (14%), Ni (4.5%), B (1.87%), Si (1.25%) and the Fe balance. The micro-hardness was evaluated onto the surface of the coating, previously prepared by grinding to reduce the as-coated roughness. The method based on recording the forcess generated during the indentation with simultaneous measurement of the load – depth curve (with UMT 2MCETR microtribometer) were used for the microhardness evaluation. In order to analyse the cohesion of the coated layer, scratch tests with progressive loading (10N, 15N and 20N) were performed on the same microtribometer. Tests have shown that the metal matrix uniformly includes the hard particles arised from the core of the wire, and at the microstructural level, the microhardness varies significantly, depending on the hardness of the particles on which the indentor tip applies the loading forces. However, the overall behavior of the coatings thus realized is a satisfactory one, being, as a general behavior, in the average required by the applications of such a layer.

Influence of factors of the electric arc spraying process on the properties of coatings

Influence of factors of the electric arc spraying process on the properties of coatings

Formation of reflective shells by electric arc spraying and application of composite material to the punch

In the course of the work, the process of forming reflective shells and finding the position of grid elements after deformation was investigated. Fixation of mesh nodes by electric arc spraying. After that, a composite material such as polystyrene is applied to form reflective shells. Minimization of potential energy is carried out numerically by an iterative method. The result of the work is the formation of the antenna array shell by the method of electric arc spraying and the application of the composite material. The following forming operations of sheet metal stamping are known: drawing, rotary drawing, relief forming, trimming, including rubber and liquid drawing, hydromechanical drawing, explosion drawing, electric discharge stamping, electromagnetic stamping, hydropneumatic drawing, which allow to obtain a shell from sheet material (solid or gas and water permeable) by pressing it against a die or punch with a transfer medium.

INVESTIGATION OF THE PROCESS OF ELECTRIC ARC METALIZATION OF COATINGS FROM STEEL 30KhGSA

The article considers the electric arc metallization technological modes of steel 30KhGSA wires, which affect thestructure formation and properties ofcoatings.Electric arc spraying was carried out using an SX-600 electric arc metallizer. The properties and characteristics of the resulting coatings depend on several plating parameters such as wire feed speed, voltage, and amperage. The coating structure was studied by electron microscopy and metallographic analysis. The coating has a layered structure, which consists of frozen convective metal flows, micro-welded small metal particles and oxides. The results of the study show that an increase in the wire feed speed during metallization leads to an increase in the resulting coating thickness per unit time. On the surface of steel 45, depending on the selected mode, coatings were formedfromsteel30KhGSAwithathicknessintherangefrom50μmto370μm.Ithasbeenestablishedthat when electric arc metallization coatings are sprayed with 30KhGSA wire, the microhardness of the surface layer increases by a factor of 2 relative to the microhardness of 45 steel. Based on studies investigating the impact of various factors in the electric arc spraying process on the formation of coating structures and properties, it can be deduced that utilizing electric arc metallization on steel 30KhGSA substrates allows for the production of coatings with enhanced hardness.

Corrosion behavior and mechanism of electric arc-sprayed Al-Mg coating and Zn-Al-Mg pseudo-alloy coatings

Pseudo-alloy coatings produced using the electric arc spray method are economical for corrosion protection in large-scale applications. In this study, the corrosion behaviour of two Zn-Al-Mg pseudo-alloy coatings (Al-5%Mg wire + Al-50%Zn wire and Al-5%Mg wire + 99.9%Zn wire) is investigated. A reference coating (Al-5%Mg) is also tested for comparison. The results show that the variation in the Zn content significantly affects the corrosion mechanism, including corrosion kinetics, corrosion development pathway, and corrosion products. Selective dissolution is inevitable in the pseudo-alloy coatings due to the phase segregation caused by multi-galvanic systems. Severe corrosion reactions can occur if these galvanic cells are confined in a limited space, such as in a single colony. If the electrodes of these galvanic cells are relatively large, the dissolution process can be slow but continuous. Both Zn-Al-Mg pseudo-alloy coatings exhibit improved corrosion resistance due to the barrier effect of the AlMg splats and can provide adequate sacrificial protection owing to the more negative corrosion potential of the Zn-rich splats.

Electric arc synthesis of Al2O3 nanoparticles of various sizes

This article discusses the synthesis of hollow Al2O3 nanoparticles via electric arc spraying and subsequent material calcination in air. The effect of buffer gas pressure on the size and thickness of the synthesised hollow nanoparticle enclosure is investigated. Based on experimental data and numerical modelling data for the respective processes, a mechanism for the formation of various-sized nanoparticles based on changes in the residence time of carbon is proposed.

Corrosion Resistance of Pseudoalloy Copper-Iron Coatings Obtained by Electric Arc Spraying

Corrosion Resistance of Pseudoalloy Copper-Iron Coatings Obtained by Electric Arc Spraying

Study on microstructure, mechanical and wear resistance properties of arc sprayed Al‐Mg alloy coating

AbstractIn this investigation, Al‐Mg alloy coating samples were deposited by the electric arc spray technique on SS400 steel substrate at various spraying parameters, namely, the spray current (150, 200 and 300 A), the air pressure (4, 4.5 and 5.5 bar) and the stand‐off distance (100, 162.8 and 200 mm). The structure morphology, phase composition, porosity, microhardness, adhesion and wear resistance of the coating were studied. The obtained results showed that the coating at the spray current of 300 A, the air pressure of 5.5 bar and the stand‐off distance of 162.8 mm has the lowest porosity and highest microhardness. In addition, this coating also has better adhesion to the steel substrate and wear resistance than other coatings. Moreover, X–ray phase analysis showed that the following phases are created on the surface of the Al‐Mg coatings: Al, Al2MgO4 and Al3Mg2.

Effect of the Surface Chemical Composition on the Corrosion Resistance in the Mixture of FeCrMoNbB (140MXC) and FeCMnSi (530AS) Coatings Produced with the Electric Wire Arc Spraying Technique: Part I.

In this study, FeCrMoNbB (140MXC) and FeCMnSi (530AS) coatings were simultaneously projected on the substrate AISI-SAE 4340 using the electric wire arc spraying technique. The projection parameters, such as current (I), voltage (V), primary air pressure (1st), and secondary air pressure (2nd), were determined using the experimental model Taguchi L9 (34-2). Its main purpose is to produce dissimilar coatings and to evaluate the effect of the surface chemical composition on the corrosion resistance in the mixture of 140MXC-530AS as commercial coatings. Three phases were considered to obtain and characterize the coatings: Phase 1: Preparation of materials and projection equipment; Phase 2: Coatings production; and Phase 3: Coatings characterization. The characterization of the dissimilar coatings was carried out using the techniques of Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX), Auger Electronic Spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The results of this characterization corroborated the electrochemical behavior of the coatings. The presence of B was determined with the XPS characterization technique in the mixtures of the coatings in the form of Iron Boride. Moreover, the XRD technique showed Nb in the form of FeNb as a precursor compound for the 140MXC wire powder. The most relevant contributions are the pressures, provided that the quantity of oxides in the coatings decreases with respect to the reaction time between the molten particles and the atmosphere of the projection hood; moreover, for the corrosion potential, the operating voltage of the equipment does not exert any effect since these tend to remain constant.

Thermal Spray Coating Technology – A Review

Thermal spray coating involves heating of coating materials (ceramic, carbide, and metal alloys) to a semi-molten or molten state and propels to substrate. The flame temperature is in the range of 3,000 to 16,000OC but the surface temperature of the substrate rarely exceeds 500 OC depending on the thermal spray processes being used. The coating materials are feed into the spray gun in the form of powders, rods or wires. Thermal spray coating is use for the following purposes; (i) increase corrosion and wear resistance, (ii) protection against electromagnetic, or electrostatic, (iii) protection against radio frequency interference, (iv) metal buildup and, (iv) cosmetic. Thermal spray coating can be categorized into five most common processes; (i) Flame arc spraying, (ii) Electric Arc spraying, (iii) Plasma arc spraying, (iv) High-velocity Oxy/Fuel (HVOF) and (v) Detonation Gun. In this paper, thermal spraying processes will be explained, along with the advantages and disadvantages of one another.

Study of corrosion behavior of arc thermal sprayed Al-Mg alloy coating

In this study, Al-Mg alloy coatings were deposited on a C45 steel substrate by using the electric arc spray technique. The corrosion behavior of the coating was studied by electrochemical measurements and salt spray tests. The electrochemical tests were performed in 3.5 wt.% NaCl solution. Polarization tests indicated that the corrosion potential of the coating is significantly more negative than that of steel substrate after 240 hours of immersion. EIS measurements showed that after 24 hours of immersion, the total impedance increased with increasing the immersion time. This could be due to sealing of pores by corrosion products which hinder further penetration of the solution through the coating. Red rust spots did not appear on the surface of the coating after 1360 hours of salt spray test. The corrosion rate of the coating decreased with the increase in salt spray test time. After the salt spray test, the coating surface pitted and the cross section of the coating appeared with many long voids. In addition, XRD analysis proved that the main corrosion product was Al(OH)3. The results obtained indicated that arc thermal sprayed Al-Mg alloy coatings can reliably protect steel structures against corrosion in chloride-containing aqueous solutions.

Investigation of the properties of coatings obtained by electric arc spraying

The paper considers possibilities to increase the wear resistance, corrosion resistance, and service life for parts of machines and mechanisms via their hardening and renovating using electric arc coatings characterized by high density, adhesion strength, and micro hardness. Also, the possibility of controlling the properties of restored surfaces owing to choice of the related equipment with required structure and characteristics in order to prolong the service life of machinery parts is shown. The right choice of equipment for spraying makes it possible to increase the speed and temperature of the spraying gas and particles, reduce the droplet diameter, increase the density and reduce the oxidation of coatings. The influence of spray factors such as the flow rate and pressure of working gases, composition of combustion mixture, spraying distance, dispersion of the spray, properties of wire material, etc. on the properties of the coatings obtained has been investigated.

Restoration of a tractor part by the method of electric arc metallization

Relevance. Tractors are distinguished by long inter-service ranges and easy maintenance. But if the tractor components are not serviced in a timely manner (oil change, filters, and so on), the resulting contamination will begin to damage the parts, and increased friction will contribute to their wear and overheating. Since there is currently an acute shortage of original spare parts and their prices are quite high, the development of technological solutions for the restoration of worn-out seats of tractor parts is relevant. One of the coating methods, namely electric arc spraying, can solve this problem. The purpose of the study: using the example of the drive axis of a cylindrical straight tooth gear of a “John Deere” tractor, develop a technology for restoring a worn-out seat by electric arc spraying for the installation of a bearing or an oil seal. Methods. The brand of the axis material corresponding to the Russian analogue has been determined. The hardness of the axis base was measured with a TK-2M hardness tester. Preliminary mechanical treatment of the restored surface has been carried out. Additionally, jet-corundum treatment of the worn surface was carried out. The technology of electric arc spraying has been applied to obtain the necessary coating. Turning of the restored surface was performed until the nominal diameter of the axle seat was obtained. Results. The technology of restoration of the axle seat by supersonic electric arc spraying has been developed. The expediency and necessity of preliminary mechanical action on the seat, consisting in threading and jet-corundum processing, before the process of supersonic electric arc spraying are established. The results of the study showed the effectiveness of the electric arc spraying method for restoring the worn-out seat of the drive axis of a cylindrical straight tooth gear in tractors. The cost of restoring one worn-out axle seat was 3,000 rubles, which is more than 10 times cheaper than the original spare part. At the same time, all the mechanical properties of the part have been preserved. It is recommended to use the method of electric arc spraying to restore the worn-out seat of the axles of all imported agricultural machines.

Визначення впливу газодинамічних параметрів струменя на ступінь деформації частинок під час електродугового напилення

The paper analyzes the scientific and technical information on the process of propagation of a heterophase turbulent jet with particles of the solid phase during electric arc spraying. It has been established that data on determining the parameters of impact and deformation of sprayed particles are currently incomplete, which is of great importance when choosing the optimal temperature-time parameters for the subsequent heat treatment of the formed coatings. The calculation of the main gas-dynamic parameters for electric arc spraying was carried out: the velocity of air and sprayed particles along the jet axis and along its cross section at a spraying distance of 100 mm. It has been established that the air velocity in the initial section of the jet is constant and is about 310 m/s. At a distance of about 35 mm, this section ends and the air velocity begins to decrease and at a spraying distance of 100 mm it is 135 m/s. It is shown that in the initial section of the jet, the sprayed particles are accelerated and reach a maximum velocity of about 80 m/s. With a further increase in the distance from the nozzle exit, the particles gradually lose speed and at a spraying distance of 100 mm it is about 75 m/s. Based on the determination of the surface tension, the average drop size of the Sv-08G2S wire was calculated upon separation from the electrode (214 μm) and on approaching the substrate (82 μm). Taking into account the data obtained, a calculated determination of the deformation degree of the sprayed particles along the spraying spot at a distance of 100 mm was made. It has been established that particles along the flow axis have the highest degree of deformation (about 86 %), which is explained by their high kinetic energy. The average value of the diameter of sprayed particles at a distance of 100 mm was experimentally determined when spraying Sv-08G2S wire (84 µm) into water, which correlates well with the calculated value. A cross section was prepared and the degree of particle deformation along the spray spot was determined. A comparative analysis of the calculated and experimental data on the degree of particle deformation was carried out, which showed the difference between them to be no more than ±1 %.

Залежність структури електродугових покриттів від параметрів напилення деталей транспортної техніки

The use of special flux-cored wires for electric arc spraying allows for coatings with high wear resistance. However, the insufficient adhesion and cohesion of the resulting coatings does not allow these coatings to be used under increased operating loads. To improve the mechanical characteristics of gas-thermal coatings, a supersonic gas jet is used to transport molten droplets to the sprayed surface, increasing their kinetic energy. It is proposed to apply a supersonic air jet using a Laval nozzle and increasing the air jet pressure from 0.6 to 1.0...1.2 MPa. The aim of the study is to determine the effect of air jet pressure on the structure of electric arc coatings. It has been determined that an increase in the air jet pressure from 0.6 to 1.2 MPa causes a 2-fold increase in the air flow velocity from 300 to 600 m/s. At the same time, the velocity of droplets dispersed by the air jet during the spraying of electrode cored wires increases from 60-90 m/s to 160-220 m/s, and their size decreases. Reducing the flight time of the dispersed droplets from the arc to the sprayed surface ensures their higher temperature when they hit the sprayed surface. Increasing the air jet pressure also reduces the expansion angle of the metal-air jet from 30° to 15°. The microhardness of iron oxide inclusions - magnetite, wustite and hematite - in the coating of unalloyed steel wire sputtered is in the range of 700-800 HV. This ensures a microhardness of the U8 coating of 350-400 HV at a pressure of 0.6 MPa. Sputtering the same coating at a pressure of 1.2 MPa reduces the size of the lamellae and oxides, and their volume content increases, which increases the microhardness to 450...500 HV. The microhardness of coatings made of 90X17R3GS increases from 800 to 910 HV. It was found that an increase in air jet pressure from 0.6 to 1.2 MPa provides an increase in air jet velocity from 300 to 600 m/s, and the velocity of dispersed droplets from 120 to 220 m/s.

Вплив складу шихти порошкових дротів на механічні властивості та корозійну стійкість електродугових покриттів

Electric arc spraying of coatings is common in many branches of industrial production, in particular to restore the geometry of machine parts worn in operational conditions, to increase their protection against abrasive and gas-abrasive wear (at the same time, both at climatic and at technologically determined elevated temperatures). Coatings sprayed using powdered wires are characterized by high chemical heterogeneity, which significantly distinguishes them from electric arc coatings made of solid wires. This is due to the different chemical composition of the droplets formed from the molten powder wires and carried by the air jet to the surface of the substrate, forming a coating on it. The charge with alloying elements in its composition (including difficult-to-melt ones such as FH, B4C, FHB) does not have time to fully melt and mix with the melt of the steel shell. It is clear that because of this, the melt droplets of flux-cored wires dispersed by an air jet will have a different chemical composition and , as a result, the coatings formed from these droplets on the surface of the substrate will be characterized by high heterogeneity and significant chemical heterogeneity, which will affect their physical and mechanical properties at different operating temperatures and especially when exposed to corrosive environments. To ensure high corrosion resistance of electric arc coatings in aggressive environments, it was necessary to reduce their chemical microheterogeneity and achieve a sufficiently high chromium content (it should be more than 12 wt.%) in each of its lamellae. To achieve this goal, ingredients were added to the composition of the charge, which enabled the formation of eutectics with a low melting temperature, with the dissolution of such refractory components of the powder wire charge as carbides, borides, refractory metals and alloys. Microhardness measurements showed that the highest hardness was achieved by electric arc coatings made of powder-coated wires №. 2 (20X16Р3Н2ГС) and powder-coated wires №. 5 (Х17Р3С). This happened due to the presence in the charge of 3 wt.% of boron, which entered their charge as part of the FHB-2 ferrochromiumboron powder. Phase analysis of these EDPs revealed the segregation of finely dispersed FeCrB and FeCr2B borides in their ferrite structure. However, the cohesive strength of these coatings did not exceed 100 MPa. This was explained by the fact that during filing, residual first-order tensile stresses could occur in their structure, which, as a rule, contribute to the cracking of the coatings during their subsequent mechanical processing. Therefore, before applying coatings from such powdered wires, the base for spraying should be heated to 150...200ºС. Conclusions. 1. To ensure complete fusion of the components of the powder-coated wire charge with each other and with its steel sheath, it is proposed to add Fe-Mn, Fe-Si ferroalloy powders to the powder-coated wire charge, which are able to interact with the refractory components of the charge with the formation of low-temperature eutectics. The legality of such a component composition of the charge of flux-cored wires as an effective method of reducing the melting temperature of the components has been experimentally substantiated. 2. The addition of ferrosilicon, ferromanganese powders and self-fluxing alloy PН-10Н-01 to the charge of flux-cored wires based on ferrochromium and ferrochromium ensured high hardness of electric arc coatings, low heterogeneity of the chromium content in the lamellae, and, as a result, high corrosion resistance, which comparable to that of stainless steel

Study of the wear behavior of bronze coatings deposited by the EAS method

Research in the present paper has highlighted the availability of using bronze coatings, obtained by electric arc spray (EAS) method, for the purpose of increasing the life time of materials tested for abrasive sliding wear. The experimental plan of the work includes the analysis of three types of samples: S1 (samples deposited with a CuAl 90-10 layer on a steel-type base material), S2 (casted sample from CuAl9 material) and S3 (bearing material sample). The sliding wear analysis were obtained on a specific testing machine in a lubricated environment (clean oil) at a preset loading, obtaining both the friction coefficient for each material type and the material loss for each sample. The results showed an average strength of the bronze coated sample (S1), its mechanical characteristics being higher to the other two analyzed samples.

ELECTRIC ARC COATINGS WITH A COMPLEX OF IMPROVED PROPERTIES FOR REPAIRING AND HARDENING OF MINING MACHINE PARTS

Purpose. Research and analysis of the possibilities of using electric arc coatings with improving properties in the repair of machines and mechanisms for mining industry.
 Methodology. The porosity of the obtained electric arc coatings was studied using computer metallography. The hardness was determined on a Vickers-type device. The thermophysical properties of the coatings were studied using the dynamic calorimeter method. The adhesion strength of the coatings to the substrate was determined by the method of "pulling the pin". Determination of wear resistance was carried out on the SMC-2 friction machine according to the "roller-block" scheme in conditions of limited lubrication. The determination of coherent x-ray scattering regions to estimate the size of the substructure of the coating material was carried out by x-ray diffraction analysis on the DRON-3 installation.
 Results. An electric arc sprayer has been improved, which makes it possible to improve the quality of composite coatings by increasing the particle velocity in a high-temperature heterophase jet and reducing its opening angle, which leads to an increase in the CMM during spraying from 0.63 to 0.74. At the same time, the increase in the hardness of the metal matrix in the composite electric arc coating is 21%, their adhesion strength to the base increases by 26%, wear resistance is 6.9 times compared to the unfilled coating. The optimal amplitude-frequency parameters of the electric pulse action during electric arc spraying of the SV-08G2S wire (pulse frequency – 6.5 kHz, amplitude – 5 kV) are determined, which provide an increase in hardness up to 35%, adhesion strength to the substrate up to 30% and wear resistance of coatings 1.7 times due to grinding and acceleration of the sprayed particles. The optimal temperature-time parameters of pre-recrystallization heat treatment are established, which provide a further increase in the hardness of coatings due to the grinding of subgrains to the nanoscale size inclusive. The possibility of thermal stabilization of the polygonization substructure of electric arc coatings obtained by spraying 12X18N10T wire by their additional plastic deformation is shown.
 Originality. The electric arc coating method was further developed by improving the design of the spray head, which made it possible to increase the material utilization rate during their spraying and physical and mechanical, as well as operational properties. The regularities of the influence of electric pulse action on the microstructure and physical and mechanical properties (hardness, density, adhesion strength, thermal conductivity, wear resistance) of electric arc coatings are established. The process of pre-crystallization treatment of sprayed coatings in the direction of thermal stabilization of the polygonization substructure due to subsequent deformation of the obtained coatings was further developed.
 Findings and practical implications. The application of the research results obtained in this work provides an opportunity to expand the range of cheaper sprayed materials for coating with increased physical, mechanical and operational properties on heavily loaded parts of mechanical engineering, electrical products and parts of the military-industrial complex.
 Keywords: electric arc composite coatings, electric pulse action, heat treatment.

Improvement of corrosion and stress corrosion properties of magnesium alloys by coating aluminum with the electric arc spray method

AbstractIn this study, corrosion and stress corrosion behaviors of AZ31, AZ61, and AZ91 magnesium alloys coated with aluminum by the electric arc spray method were investigated in 3.5 wt.% NaCl solution. Structural properties of coated materials were investigated by scanning electron microscopy (SEM), energy dispersive X‐ray analysis, and X‐ray diffraction. Electrochemical properties were determined using the potentiodynamic polarization method in 3.5 wt.% NaCl solution. Potentiodynamic polarization curves showed that corrosion current density values did not change with coating in aluminum‐coated samples by the electric arc spray method. In contrast, corrosion potential value increased toward positive values. Slow strain rate test (SSRT) was used to determine the stress corrosion behavior and stress corrosion indexes (ISCC), ultimate tensile strength (UTS), and elongation of AZ31, AZ61, and AZ91 magnesium (Mg) alloys were determined. As a result of the SSRT, the aluminum coating process decreased significantly the stress corrosion indexes of AZ31, AZ61, and AZ91 Mg alloys. The fracture of surface images was also examined in the SEM, and both intergranular and transgranular stress corrosion cracking were observed in all three alloys.

Properties of coatings obtained by electric arc spraing for renovation of parts of machines and vehicle mechanisms

The robots present the results of investigating the power of coatings, excluding electric arc (EAS) filings, and their comparison with the powers of coatings, excluding gas-flame filings. The porosity of the coating, taken from electric arc filings, was in the range of 8-10%. the adhesion strength was 80…100 MPa. The results of the investigations show the advantages and purpose of using electric arc sawing to improve and move the capacity of machine parts and transport mechanisms. In the work, the following factors are added to the process of electric arc sawing: storage of fuel sum, distance of sawing, dispersion of sawing and other. on authority cover. In the course of the investigation, the increase in resistance, adhesive strength, coating thickness, the term for the coating thickness, was determined by the parameters of the electric arc filing. The robots have considered the possibility of securing the necessary authorities influencing the surface with the method of advancing the resource of machine parts by way of regulation by the factors of EAS. Regulating the smoothness and temperature of the stream of transporting gas and particles, you can change the diameter of the droplet, increase the width and reduce the oxidation of the coating. The results of comparative analysis of the properties of coatings applied by electric arc spraying (EAS) using the products of combustion of propane-air mixture and gas-flame spraying (FSP) using gas-air mixture are presented. Under optimal conditions of the spraying process, the porosity of the coatings obtained by electric arc spraying is much lower compared to gas-flame spraying: 8-10% and 20-30%, respectively. Adhesion strength of coatings obtained by electric arc spraying increased by 1.8-2.2 times (from 30-40 MPa in gas-flame spraying to 100 MPa in electric arc), wear resistance increased by 2-2yu5 times.