Electric Arc Metallization Research Articles

USE OF ELECTRIC ARC METALLIZATION TO PROTECT METAL SURFACES FROM CORROSION: A STUDY ON THE EXAMPLE OF STEEL 45 AND 30HGSA WIRE

The effect of protective coating applied to steel 45 made of 30HGSA wire by electric arc metallization on corrosion resistance compared to untreated steel 45 was investigated. The test methodology included electrochemical analyses such as polarization curves. The results showed that steel 45 coated with 30HGSA wire shows significantly higher corrosion resistance compared to standard steel 45.The result of this study confirms the significance of electric arc metallization technology as an effective way to improve the corrosion resistance of steels. The application of protective coating of 30HGSA wire on steel 45 not only improves its characteristics, but also provides opportunities for more durable use in aggressive environments. Also, these methods can be adapted for other types of materials, which opens new perspectives in the field of steel structures protection. This research can serve as a basis for the development of new norms and standards in metal fabrication and processing. These results provide valuable scientific data that can contribute to the development of improved corrosion resistant materials for applications in critical industries such as oil and gas, marine and construction projects, and mechanical engineering, where material reliability is a key factor.

INFLUENCE OF GAS ENVIRONMENT OF SPRAYING ON THE PROPERTIES OF GAS-THERMAL METALLIZED COATINGS

This article is devoted to the study of the influence of the technological parameters of spraying, in particular the gaseous medium, on the physical and mechanical properties and corrosion resistance of gas-thermal metallization coatings. To protect the housings of submersible electric motors (PAD) in oil and gas wells, the method of electric arc metallization (EDM) has become widespread, due to the high level of physical and mechanical properties of the resulting gas-thermal metallization coating, high productivity and cost-effectiveness of the process, as well as the mobility of equipment. Despite the effectiveness of this method of protection, it does not exclude the occurrence of corrosion processes in the metal of the PAD body. In this regard, research aimed at increasing the operational life of the metallization coating is relevant and promising.The article considers the theoretical aspects of the influence of the technological parameters of the spraying process on the properties of the metallization coating. The effect of the sputtering gas medium on the physical and mechanical properties and corrosion resistance of metallization coatings has been experimentally investigated. Comparative tests and studies of gas-thermal metallization chromium-nickel coatings applied by the EDM method in an air environment and in an argon environment have been carried out. The main trends and features of the formation of metallization chromium-nickel coatings applied by the EDM method and the effect of the application mode, in particular the technological gas spraying medium on the microstructure studied on metallographic grinds using a scanning electron microscope with an attachment for energy dispersion analysis; microhardness determined by the Vickers method are determined; The wear resistance is determined by abrasive wear during friction against non-rigidly fixed abrasive particles and the corrosion resistance of the resulting coatings, determined by autoclave tests during exposure in a simulated environment containing corrosive components.The study of the influence of certain technological parameters of spraying of gas-thermal metallization coatings, including the gas medium, on the properties of the coatings obtained is a fairly promising task aimed at increasing the operational life of the metallization coating, which in the future will reduce the cases of premature failure of oilfield equipment.

Дослідження відновлення корпусних деталей автомобільних двигунів методом електродугової металізації

Road transport ensures a rational organization of production and transportation of products. The cylinder block is a basic part, mechanisms and engine parts are attached to it. Engine blocks are operated with high loads. Defects arise and develop, which can be eliminated during major repairs. Improving the methods of restoring worn cylinder blocks of automobile engines is an urgent task. The possibility of restoring parts with such defects by gas-thermal methods was considered. The total level of defects that can be eliminated by applying a restorative coating by the method of electric arc metallization is 37%. The analysis of literary sources shows that surfacing and welding methods do not ensure the quality of the restored part. Gas-thermal methods are often used in the process of repairing parts. The most technological and effective is electric arc metallization. Productivity of electric arc metallization can be very high. Operating costs of using electrometallization are small. The equipment is relatively simple. Restoration of parts by electric arc metallization increases wear resistance and durability of the engine. To assess the repeatability of block defects, we analyzed a sample of 20 truck cylinder blocks from different manufacturers. It was established that the resource of the block depends on: wear of the main bearing beds, holes, cracks, damage to the thread and breakage of pins and holes. Laboratory experiments on the application of electroplating coating were carried out on samples of high-strength cast iron. Preparatory processing of samples - shot blasting. Experiments on sputtering of samples were carried out with known powder wires PG-SR4 and PG-SR4+3% Al with a diameter of 2.0 mm. Spraying was carried out with an EM-17 electric arc metallizer. Tests on the adhesion strength of the coating to the base metal were carried out using the adhesive method. From the research results, we can see that the coating applied with PG-SR4+3%A1 wire is destroyed at the joint under a higher load than the corrosion formed by PG-SR4 wire. At the same time, the adhesion strength also exceeds, and is 22.9 MPa. The microhardness of the coating built up with powder wire PG-SR4+3%A1 exceeds the level of microhardness of the surface built up with wire PG-SR4. Microhardness in both cases. decreases with distance from the surface of the deposited layer. Conclusions. From the conducted research, it follows that the electric arc restoration does not have a thermal effect on the part, provides high adhesion strength of the applied layer, which prevails over the majority of traditional methods of restoration of parts. In addition, the method of electric arc metallization is characterized by low energy consumption, small-sized and mobile technological equipment. Therefore, there is a need to continue the research of electric arc metallization in the restoration of worn surfaces of car parts.

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.

Investigation of the Technology of Restoration of the Eccentric Sleeve of a Cone Crusher by Electric Arc Metallization

A solution of two problems is proposed. The first task was technological, in which one of the ways of repairing and restoring the involved part was considered – the restoration of the eccentric sleeve of the GP 500 cone crusher for fine and fine crushing of ores by electric arc metallization. The second task is mathematical. A computational and theoretical analysis of the choice of optimal EDM modes for obtaining a high-quality coating with antifriction properties on the surface of an eccentric sleeve is carried out.Conclusion on research work: - a decrease in the purge flow rate leads to an increase in the influence of the aerodynamic drag coefficient of the air on the movement of the parts of the molten particle, i.e. the time during which the molten metal is collected into the spherical part of the particle increases, therefore the diameter of the sprayed particles increases; - materials selected from copper and steel wire make it possible to obtain a coating of the surface of the sprayed part with high antifriction properties, which increases the strength and service life of the eccentric sleeve restored in the operation of the cone crusher; - in this paper, an alloy consisting of two metals is presented and studied, but today there are a huge number of possibilities in choosing various modern coatings used for parts operating under conditions of intense abrasive wear, significant shock loads, pressure, rolling, friction, sliding of metal surfaces. As an innovation in electroplating technology, it is proposed to continue research on a larger scale with further determination of stronger alloys.

RESEARCH OF WEAR RESISTANCE AND MECHANISM OF ABRASIVE WEAR OF GAS THERMAL METALLIZED COATINGS USED FOR SEM PROTECTION

As is known, the current stage of the development of the oil industry of the Russian Federation is characterized by complicated conditions for field development, which is due to low production rates due to the high viscosity of oil, high aggressiveness and water cut in the media. Almost the entire well stock is operated mechanically, mainly with the help of electric submersible pumps (ESPs). To date, the use of metallization coatings applied by thermal spraying, due to their high physical, mechanical and chemical properties, is the most effective way to protect submersible equipment in the mining industry, in particular, the body of a submersible electric motor (SEM) from the influence of complicating factors. Nevertheless, there have been repeated cases of a decrease in the service life of equipment associated with the processes of destruction of metallization coatings. Abrasive wear is one of the most common reasons for the destruction of gas-thermal metallization coatings of SEM cases during operation. This article presents an overview of the main parameters that determine the wear resistance of gas-thermal metallization coatings, the main wear mechanisms and types of coating damage during wear are considered. Comparative tests of the wear resistance of gas-thermal metallization coatings deposited by the methods of electric arc metallization (EDM) and high-speed flame spraying (HSFP) under the influence of abrasive particles were carried out. It has been established that the destruction of gas-thermal metallization coatings proceeds mainly by chipping particles, for metallization coatings that have refractory compounds in their composition, fatigue failure is also characteristic, due to the accumulation of internal stresses during highcycle elastic-plastic deformation of the coating, which contribute to the formation of fatigue cracks and subsequent separation of particles with surface layer. The results obtained confirm the significant effect of the uniformity of the structure of gas-thermal metallization coatings on their wear resistance, as well as the staging of the wear process.

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.

THE USE OF SUPERSONIC ELECTRIC ARC METALLIZATION TO PRODUCE CORROSION-RESISTANT COATINGS OF AGRICULTURAL MACHINERY PARTS

During seasonal work, as practice shows, the paintwork is subject to damage, which leads to the appearance of corrosion foci on steel structures, the removal of which requires considerable labor. The applied paint coatings of agricultural machinery are short-lived, therefore, the development and implementation of new progressive methods of protecting parts of agricultural machinery from corrosion is important. (Research purpose) The research purpose is to extend the service life of agricultural machinery by creating an anticorrosive coating by supersonic electric arc metallization with subsequent application of paint and varnish coating. (Materials and methods) Abrasive blasting with corundum was performed for preliminary preparation of the surface of the parts before coating by electric arc metallization. A specialized installation for electric arc supersonic metallization «Dragon» was used for coating, zinc-aluminum wire Zn85/Al15 was used as the applied material. (Results and discussion) Selected equipment for the preparation of parts and assemblies and the application of anticorrosive coating by supersonic electric arc metallization. We have completed the layout of the site for coating. The modes of supersonic electric arc metallization were established. The modes of obtaining high-quality and durable coating of products were worked out on the basis of the Kaluga Region state enterprise «Kaluga Machine-Technological Station». (Conclusions) Anticorrosive treatment of products operating in aggressive environments is most effective when two coatings are applied sequentially: anti-corrosion layer by electric arc metallization and subsequent application of a layer of paint and varnish coating. The use of the technology of abrasive blasting and anticorrosive protection of housing and frame structures of agricultural machinery by the method of supersonic electric arc metallization allows extending the service life of these structures for 12 years.

Properties of coatings obtained by supersonic electric arc metallization with aerosol fluxing

The method of electric arc metallization has both undeniable advantages and some disadvantages. For example, there is a burnout of alloying elements and a high content of oxides in the applied coating. Aerosol fluxing during metallization can solve this problem and neutralize the negative oxidative effect of interaction of the applied metal with air oxygen. This article discusses an effective method to improve physical and mechanical properties of an electrometallization coating using aerosol fluxing. The essence of this method is introduction of an aerosol together with compressed air into a torch of molten metal. This aerosol consists of an aqueous solution of the chemical inorganic materials. Such the aqueous solution is poured into a hydrodispergator, which is connected to the air channel of the metallizer. Aerosol fluxing makes it possible to deoxidize and ligate metal during electric arc metallization. As a result, the physical and mechanical properties of the metal increase. The paper considers the results of topographic studies of electrometallization coatings. Formed coatings have a structure with grain sizes from 200 to 2500 nm and also have pronounced and subtle grain boundaries. Aerosol fluxing with electric arc metallization forms a coating with finer-grained structure, which increases their strength. It is established that formed coatings have a finer-grained structure and increased strength when using aerosol fluxing during electric arc metallization. Metallographic studies showed that the thickness of the electrometallization coating varies from 2490 µm to 2586 µm. The use of aerosol fluxing during electric arc metallization does not significantly affect the coating thickness. The microhardness of electrometallization coatings was studied. This study showed that the use of aerosol flux consisting of Na2CO3 , Na3AlF6 , Na2B4O7 during metallization increases microhardness of electrometallization coatings by 1.6 – 1.9 times.

НАПРАВЛЕНИЯ СОВЕРШЕНСТВОВАНИЯ ЭЛЕКТРОДУГОВОЙ МЕТАЛЛИЗАЦИИ

The main directions and ways of improving electric arc metallization (EDM) are considered. Improvement of physical and mechanical properties of metallization coatings, in addition to the use of modern consumables, can be achieved by increasing the metal-air flow rate, the use of activated arc metallization and aerosol fluxing in EDM. The paper presents the developed equipment for EDM, and the improvement of EDM technology in the above areas.

DEVELOPMENT OF THE TECHNOLOGY FOR IMPROVING THE STRENGTH CHARACTERISTICS OF GAS-THERMAL COATINGS USING THERMODYNAMIC EFFECTS

The application of various types of functional and protective coatings made of inorganic materials to parts made of conventional structural materials will be able to solve the issue of ensuring the planned service life of modern devices, machines and mechanisms. Electric arc metallization, characterized by relatively high productivity and low cost of coating, serves as one of the methods of applying gas-thermal coatings. However, the high porosity of the resulting coatings, their low adhesion strength to the substrate and plastic properties prevent the widespread use of this method. (Research purpose) The research purpose is in studying the chemical, thermal and mechanical effects on samples obtained by electric arc metallization, on the adhesive, cohesive and strength properties of the coating and the areas of connection of the coating with the substrate. (Materials and methods) The authors used electric arc metallization and gas-dynamic spraying to obtain the necessary coatings. A mechanical effect on the coating was studied using the machine IZH- 250TV and special research equipment to determine the properties of coatings and substrates. (Results and discussion) Gas-thermal coatings can be successfully used in the manufacture of new and restoration of worn parts of agricultural machinery. The processing of metallized samples by surface plastic deformation are expedient and necessary. Chemical and thermal treatment has a positive effect on the properties of the coating and the substrate, increasing the value of microhardness by 50-70 percent. The use of supersonic metallization devices leads to an increase in adhesive strength by 30-35 percent. (Conclusions) The study showed that chemical and thermal treatment has a positive effect on the properties of the coating. Plastic deformation of the sprayed surfaces is practically equivalent to thermodynamic effect. It is recommended to use plastic deformation for spraying cylindrical surfaces.

A Study of the Wear Resistance of the Surfaces of Components via a Strengthened Combined Electromechanical Method

The issues of the process of hardening of parts made from steel 45 by a combined method were considered, which consisted in the application of coating by electric-arc metallization, subsequent lathe work, diamond surface smoothing and pulsed magnetic refinement. Parts that were hardened by a combined method were analyzed for durability. A pilot plant for the study of parts for durability resistance was described. The results of the research are presented. The nature of wearing of the component surfaces hardened by the combined method has been established. According to the test results, it was found that in the process of wear of component surfaces hardened by a combined electromechanical method no run-in occurred. The period of normal exploitation began immediately after the start of the work. The surface of the analyzed part after burnishing deformation by the diamond smoothing method works for a long period of time practically without abrasion. According to this, wear products do not enter the friction zone and cause abrasive wear. The destruction of the surface does not affect the entire surface simultaneously, it occurs in its individual sections. Other sections are only vulnerable to physico-chemical changes. Such partial destruction and changes features of the surface affect the interaction of the conjugate surfaces. Pulsed magnetic refining also increases the wear path by changing the physico-mechanical properties of the original material. The wear stages of coating surfaces hardened by diamond smoothing and pulsed magnetic refinement last longer.

Applications of electric arc metallization method with pulsating air-spraying flow for application of coatings made from a cored wire

In order to reduce the oxidizing effect of the spraying flow on the liquid metal of the ends of the molten electrodes the method of periodic (pulsating) impact of the air spraying flow on the liquid metal of the electrodes has been previously proposed and developed, considering that the pause between the moments of the flow impacts allows ensuring the melting of the electrodes with a limited amount of air. The design of the device which provides pulsations of a stream with various frequency and duration is developed, data on the influence of a pulsing stream on technological characteristics of coatings, in particular, a considerable decrease in losses of alloying elements are received.As a solution to the problem of energy saving in arc metallization, the use of oxygen of the air spraying flow was considered in order to obtain wear-resistant coatings with high adhesion strength through the formation of solid oxides from non-deficient powders of metals and alloys.Due to a limited range of compositions of solid cross-section wires, it is suggested to use cored wires consisting of low-carbon shell and rod made of non-deficient, widely spread metal and ferroalloy powders, which provide high wear-resistant coatings with increased adhesion strength.Theeconomically alloyed flux-cored wire PP-MM-2 developed at the Department of Automation and Mechanization of Welding Production of the Priazovsky State Technical University was taken as the investigated one.In this paper, the influence of spraying airflow pulsation frequency in arc metallization on microstructure and micro hardness value of coatings obtained by using powder wires is considered

Abrasion resistance analysis of coatings at electro-arc spraying using a pulsating spraying airflow

Abstract. In the global practice of application, more than 50% are metal coatings applied by the method of electric arc metallization, which has the following advantages: high productivity, simplicity of equipment, low power consumption, the ability to 6obtaining coatings with high-performance properties through the use of scarce and inexpensive wires of industrial production.
 But the main drawback is the process of oxidation of alloying elements during transportation of molten electrode particles by spraying airflow.
 A series of scientists' works are aimed at improving the design of spray heads of electric arc metallizers, which involves improving the design of the air nozzle through the use of inserts and devices providing a change in the spraying airflow, and leads to a significant increase in the price of the process.
 To reduce the oxidizing effect of the spraying airflow on the liquid metal of the electrodes the method of pulsating air injection into the electrode melting zone has been developed.
 This paper presents the influence of the pulsating spraying flow on the indicators of abrasive wear and reduction of oxidation of metal particles, at the arc metallization to obtain coatings with the specified properties and application of resource-saving.

Elemental Distribution of Gas-Thermal Coatings with W and Ta Modifiers

Currently, the technology of arc metallization according to technical and economic indicators is a promising way to restore worn parts of equipment. In the coating process the cored wire is melted by an electric arc, and molten particles are accelerated towards the surface parts with high temperature gas flow. On the subsequent formation of strengthening coatings are significantly influenced the technological modes of electric arc metallization. As practice shows, the coatings obtained by electric arc metallization are characterized by a heterogeneous layered structure. The structure of powder coatings, the distribution, composition and properties of the phases affect on the wear resistance, hardness and strength of the machined surface of machine parts and mechanisms. It is therefore necessary a detailed study of the structure of wear-resistant coatings taking into account technological properties of cored wire, and process heating of the particles by arc spraying. In this work the X-ray microanalysis of the elements of the structure of wear-resistant coatings obtained from cored wire with a refractory additives were conducted. The results of the study will be useful for the improvement technology of electric-arc metallization cored wires.

Deposition of Pseudo-Alloy Coatings by Electric Arc Metallization

Deposition of Pseudo-Alloy Coatings by Electric Arc Metallization

Application of metallization coatings for protection of submersible electric motors of pumping equipment from influence of complicating factors in oil wells

The paper provides a review of results obtained when using metallization coatings to protect the outer surface of electric centrifugal pump (ECP) equipment against the complicating factors in oil wells. Metallization coating is applied by thermal spraying using the method selected based on the chemical composition, materials used and properties of the finished coating. The most common coatings on the Russian market are Monel and alloys based on austenitic stainless steel applied by methods of electric arc metallization or high-speed spraying. Traditional coatings obtained by thermal spraying feature by insufficiently high level of physical, mechanical and chemical properties. The studies of failed cases of submersible motors show that most critical shortcomings of the coatings used include insufficient resistance to mechanical impact and abrasive wear, higher electrochemical potential in relation to the base metal, application technology violations, and significant coating porosity. One of the main reasons for the observed shortcomings is the limited number of traditionally used methods and materials. In order to solve the problem of using protective coatings for submersible motors, significantly improve their properties, service life and economic efficiency, it is necessary to use modern achievements of science in the development of coatings to protect metal surfaces from wear and corrosion, namely: to expand the number of methods and materials for coating application; to develop a methodology for coating quality assessment; to develop a methodology for assessing the economic efficiency of protective coatings. Solving these tasks will enable a reasonable technical and economic choice of a specific submersible motor coating for specific operating conditions.

СНИЖЕНИЕ ВОЗДЕЙСТВИЯ КИСЛОРОДА НА ЖИДКИЙ МЕТАЛЛ ЭЛЕКТРОДОВ ПРИ ЭЛЕКТРОДУГОВОМ НАПЫЛЕНИИ ПУЛЬСИРУЮЩЕЙ РАСПЫЛЯЮЩЕЙ СТРУЕЙ ВОЗДУХА

In electric arc metallization an intensive oxidation of the spraying metal takes place due to the oxygen contained in the air which causes a great reduction in contents of alloying elements in the coating. In order to reduce the oxidizing impact of the air-spraying jet on the liquid metal of electrodes a method involving pulsing air feed has been developed. This is achieved by introducing an additional element into the spraying head of an electric arc metallizer.The analytical dependencies presented in this paper are to determine the level of reduction of air consumption in electric arc spraying as well as the reduction in the mass of oxygen in contact with the air. There have been represented some examples of chemical composition of coatings when air consumption is dropped by 35-40% which diminishes the energy give-out on its reproduction.

Evaluation of the content of corundum in the wear-resistant coating applied by wire arc metallization of a powder wire with fireproof additives

In this paper, the evaluation of the content of corundum (α-Al2O3) in the wear-resistant coating applied by wire arc metallization of a powder wire with fireproof additives has been carried out. One of the most promising high-energy methods of application of wear-resistant coatings is electric arc metallization wires, the use of the powder wires for the restoration of worn parts of equipment gives unparalleled flexibility in choice of coating material and in coatings with a variety of properties – high hardness and wear resistance, corrosion resistance, high heat resistance and heat resistance and etc. Coatings of about 300μm thickness were prepared through high temperature fusing of a powder wires on steel substrate. Corundum particles were used as a strengthening additive, Al2O3 particles exhibit high hardness, good wear resistance and thermal stability. The microstructure and morphology of the wear-resistant coatings were investigated. It is shown that the thickness of the deposited layers in the coating does not depend on the change in the magnitude of the current. The aim of this study was to investigate the influence of the arc metallization on the microstructure of the wire sprayed coatings. Meanwhile, the distribution of chemical elements in obtained coatings were investigated. In addition we found the dependence of the corundum content in the wire thermal sprayed coatings from current strength.

Influence of Capillary-Porous Coatings on Heat Exchanger Efficiency

The possibility of enhancing heat exchanger efficiency by applying capillary-porous coatings onto the surface of a heating element using gas-thermal spray techniques is explored. Aluminum oxide porous coating was applied by electric-arc metallization using AMC wire of 1.6 mm diameter as the coating material. Aluminum oxide coatings were applied by spraying filamentous material with a Top–Jet gun.