KR20210062503A - Surface coated body - Google Patents

Abstract

According to the present invention, a metal surface coated body is formed to enable two or more surface coating layers on a surface of a base material to have each pore penetrating the inside thereof and has a section where the pores penetrating each surface coating layer are not connected to each other on an interface where two surface coating layers come in contact with each other to increase a penetration passage where an external substance penetrates the base material and lower penetration time to increase life of a component.

Description

Surface coated body}

An embodiment of the present invention relates to a surface coating body formed on the surface of the base material.

Surface coating is a coating formed on the surface of the base material by coating, which is a coating processing method that improves the properties of the material surface, and the surface coating of a commonly used metal base material has characteristics such as abrasion resistance and hardness on the surface of the metal base material. This excellent thin film is deposited to improve the hardness of the surface to prevent damage due to external impact, or it is formed as a metal oxide film on the surface layer or a coating layer containing a material with excellent corrosion resistance and chemical resistance to prevent air, water, chemicals, etc. It is used to protect the base material.

In addition, the surface coating may be formed and used on the surface so that devices and parts used under special conditions are suitable to perform functions under the corresponding conditions. The sink roll that continuously induces the steel sheet into the hot-dip galvanizing tank to form a plating layer and then pulls it out, and the sleeve and bush that support it are melted at a high temperature. Since it operates in the molten zinc of zinc, it is a part that causes severe wear and corrosion caused by dross, which is a foreign substance mixed with molten zinc and molten zinc.

The above parts are severely eroded, eroded or corroded by hot molten zinc, and as they are continuously used for a long time under high temperature and high load conditions, the life of the base material and coating layer of the part is shortened. Due to this phenomenon, the hot-dip galvanizing process requires the process of stopping the line once every 3 to 4 weeks and replacing parts, resulting in a decrease in the productivity of the process, and there is a problem that it is not appropriate.

Accordingly, in order to solve the above problems, research has been conducted on a method of reducing wear due to friction by removing dross of molten metal, and a method of improving the structure of a plating apparatus.

Korean Patent Publication No. 10-0711444

In the metal surface coating material according to an embodiment of the present invention, a section in which the penetration path of foreign substances penetrating into the coating layer through the pores included in the coating layer is not directly connected is included in the interface, so that the time required for the foreign substance to directly contact the base material is reduced. Its purpose is to provide a multi-layered metal surface coating that can be delayed and extends the life of the base material.

One aspect of the present invention, the metal surface coating body is a base material;

A first surface coating layer formed on the base material and having at least one or more first pores penetrating the inside; And

And a second surface coating layer provided on the first surface coating layer and having at least one second pore penetrating therein,

A section in which the first pore and the second pore are not directly connected may be included at the first interface between the first surface coating layer and the second surface coating layer.

When a foreign material penetrates from the outside of the second surface coating layer to the base material through the second pore, the first pore, the first interface, and a path through the second pore may be included. Can,

It is preferable that a penetration path connecting the path passing through the first pore and the path passing through the second pore is formed at the first interface.

In addition, it is preferable that the first surface coating layer and the second surface coating layer do not have pores or that the porosity of the surface coating layer exceeds 0% and is 10% or less,

The second porosity may be less than or equal to the first porosity,

The diameter of the second pore may be less than or equal to the diameter of the first pore.

In addition, the second surface coating layer may be formed by differently from the first surface coating layer at least one or more of a composition and a coating method,

The first surface coating layer may have a thickness of 0.01 μm to 5 mm, the second surface coating layer may have a thickness of 0.01 μm to 3 mm, and the metal surface coating body may have a thickness of 0.1 μm to 10 mm.

In this case, it is provided on the second surface coating layer, and includes a third surface coating layer having at least one third pore formed therein,

It is preferable that the third surface coating layer has a third porosity less than or equal to the second porosity,

The third surface coating layer may be formed by including the same composition as at least one of the first surface coating layer or the second surface coating layer,

An average distance of a path connecting the first pores and the second pores along the first interface at the first interface may be in the range of 1 μm to 30 μm.

The metal surface coating body according to an embodiment of the present invention includes first and second surface coating layers formed on the surface of the base material and an interface therebetween, and penetrates the second surface coating layer through pores included in the second surface coating layer. By preventing the penetration path of the foreign material from being directly connected to the pores of the first surface coating layer at the interface, the penetration path of the foreign material to the base material increases, thereby extending the life of the base material.

In addition, the porosity of the second surface coating layer is formed to be equal to or smaller than that of the lower first surface coating layer to prevent penetration of foreign substances from the surface.

1 is a schematic diagram showing the penetration path of molten metal when forming a single-layer metal surface coating body,
2 is a schematic diagram showing an increased penetration path of molten metal when forming a multilayered metal surface coating body having first and second surface coating layers.

Before describing the present invention in detail below, it is understood that the terms used in the present specification are for describing specific embodiments and are not intended to limit the scope of the present invention, which is limited only by the scope of the appended claims. shall. All technical and scientific terms used in this specification have the same meaning as commonly understood by those of ordinary skill in the art unless otherwise stated.

Throughout this specification and claims, unless otherwise stated, the term "comprise, comprises, comprising" means to include the recited object, step or group of objects, and steps, and any other object It is not used in the sense of excluding a step, a group of objects, or a group of steps.

In the present specification, the porosity refers to the degree of pores existing on the surface of the particles of the coating layer or inside the coating layer, and refers to the ratio of the volume occupied by the empty space in the total coating layer volume or the area ratio of the area where pores are formed on the surface of the coating layer. Can be used.

In the gas adsorption method, in general, a gas such as nitrogen is adsorbed to measure the specific surface area of the sample surface, the size and distribution of pores, and it is possible to analyze even the closed microscopic pores. (Pore size 0.35~200nm) Mercury adsorption method is a method that analyzes the porosity, pore size and apparent density of the sample from the amount of intrusion by pressing mercury on the sample.It is possible to analyze even larger pores than the gas adsorption method. .(Pore size 3.6nm ~ 900㎛)

In addition, it is also possible to perform micropolishing of the specimen using SiC abrasive paper and diamond paste, and then photograph it with an optical microscope at 200 magnification and analyze this image with an image-pro analysis device.

The porosity (the ratio of pores to the total area), which indicates the size of pores or the amount of pores, increases the opportunity for substances such as gases, liquids, and molten solids to penetrate from the outside as the porosity increases. This means that there are many opportunities for damaging the mother agent as it is highly likely that other substances will pass through the pores. In addition, when the pores are connected to each other to form a passage, it becomes a penetration path that is a passage through which fluid moves from the outside to the inside.

The penetration path refers to the path that the fluid existing outside the coating layer passes through in the process of penetrating the inside through cracks, pores, and incorrect surface treatment of the coating layer, and penetrates from the surface of the surface coating body to the surface of the base material. Therefore, it means the path through which the fluid moves in order to directly contact the base material.

When the term penetrating is used in the present specification, it is interpreted in a broad sense including a case where both ends or two portions of an object are penetrated in a straight line and a case that passes through a path including a curve.

On the other hand, various embodiments of the present invention may be combined with any other embodiments unless clearly indicated to the contrary. Any feature indicated to be particularly desirable or advantageous may be combined with any other feature and features indicated to be desirable or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

The foreign material penetrating the surface coating layer is not limited, but the case where the foreign material is a molten metal will be described below.

1 is a schematic diagram showing a penetration path of molten metal when forming a single-layer metal surface coating body. The metal surface coating body is formed on the surface of the base material. The base material (母材) means a material to be coated in the present invention.

The use of the base material is not limited, but it may be a metal material that is used in an environment exposed to molten metal, and preferably, a sink roll and a guide that are immersed in a coating pot where molten metal is present when manufacturing a molten metal plated steel sheet. It is better to be a part such as a roll. The material of the base material is not limited, but a material containing a metal or engineering plastics having heat resistance (Polyether ether ketone (PEEK), polyetherimide), polyamide-imide, polyimide (Polyimide, PI), polybenzimidazole, etc.) or composite materials mixed with metal materials based on engineering plastics, etc. may be included.

The first surface coating layer is a coating layer formed directly on the base material. The composition of the first surface coating layer is not limited, but may include a metal composition, and is preferably an alloy based on metal carbides such as tungsten (W), nickel (Ni), chromium (Cr), ceramic material, amorphous Alloys, Inconel, Timken heat-resistant alloys, or derivatives such as nickel, chromium, and zinc metals and their chromates may be used.

Ceramic materials may include silicate ceramics made by combining natural raw materials and alumina (aluminum oxide, aluminum silicate) or oxide ceramics based on aluminum oxide, zirconium oxide, aluminum titanate and metal oxides, and silicon carbide, silicon nitride. And ceramic materials such as non-oxide ceramics based on carbon, nitrogen and silicon compounds such as aluminum nitride.

The amorphous alloy may include iron-based amorphous alloys, zirconium-based amorphous alloys, titanium-based amorphous alloys, or aluminum-based amorphous alloys using iron, zirconium, titanium or aluminum as the main material.

Inconel is a heat-resistant alloy containing nickel as the main body, adding 15% chromium, 6-7% iron, 2.5% titanium, and less than 1% aluminum, manganese, and silicon. Timken heat-resistant alloys are based on iron. It is an alloy containing 15-17% chromium, 20-27% nickel, 5-7% molybdenum, 2% manganese, and 1% silicon.

The coating method of the first surface coating layer is not limited, and preferably, electrolytic plating, electroless plating, hot dip plating, chemical plating, ion plating, liquid coating, powder coating, baking coating, carbon or nitrogen penetration to harden the surface. Case Hardening, Chemical Coatings to make a chemical film, Anodizing to improve the oxide layer, Lining to coat with fluid, Powder on a high temperature heat source such as flame or plasma Alternatively, a method including thermal spray coating in which a material in the form of a wire is melted and coated, and deposition of forming a solid coating layer on the surface by making a solid material into a gaseous state may be used.

The first surface coating layer may be formed with a uniform thickness on the base material, and the thickness may be in the range of 0.01 μm to 5 mm, preferably 0.1 μm to 500 μm. If the thickness is out of the range, the thickness of the entire metal surface coating body becomes thicker and the amount of the composition used increases, resulting in poor economy, poor adhesion, and the loss of the coating layer may occur, and the elasticity decreases due to external impact. Problems may occur. If it is not within the range, it is easily damaged by physical impact such as imprinting, and it is easily contaminated, so that property deterioration easily occurs, and there is a problem that it is easy to penetrate liquid foreign substances and thus damage the base material.

The first surface coating layer may have one or more first pores depending on the composition or coating method. The first pores may exist on the surface of the first surface coating layer, are connected inside the first surface coating layer, and pass through the upper surface of the first surface coating layer and the lower surface in contact with the base material.

Ideally, the porosity of the first surface coating layer is 0% or close thereto, but fine pores may be included in the surface coating layer in the actual coating process. Since the formed fine pores can form a path through which the fluid in contact with the surface coating layer can proceed, the lower the porosity, the better the effect of preventing the penetration of the fluid.

The porosity of the first surface coating layer may vary depending on the composition and coating method constituting the surface coating layer, and even when the same composition and coating method are used, the porosity may vary depending on the experimental conditions and equipment.

The first surface coating layer may be formed by selecting a composition and a coating method such that no pores exist or the porosity of the surface coating layer exceeds 0% and is 10% or less, and when pores are present, the porosity is preferably 0%. It is better to exceed and less than 2%.

If the composition of the coating is not made uniform, the porosity of the formed coating layer may increase.

As a coating method, plating, thermal spray coating, oxidation, painting, deposition, surface hardening, chemical treatment, lining, etc. can be used. The porosity is different for each coating method, but the process, temperature, speed, and coating material of the coating method are different. It varies depending on the mixed type, and in general, the higher the coating temperature and the faster the speed, the higher the porosity is measured.If the temperature is low and the speed is slow, the porosity may be relatively reduced, but the coating layer may be intensively formed at a specific point. There is a disadvantage in that there is a variation in thickness.

In the coating method described above, the porosity according to the coating method may appear low in the order of oxidation, surface hardening, plating, deposition, chemical conversion, thermal spray coating, painting, and lining. It is preferable to form the first coating layer by using a thermal spray coating method, or oxidation or plating method, which is secured and the required thickness is easily secured. In order to reduce the porosity of the coating layer, a coating layer may be formed in a vacuum condition or a heat treatment process may be added under normal pressure.

The size of the first pores may be in the range of tens nm to several tens µm, may be in the range of 10 ㎚ to 50 µm or in the range of 10 ㎚ to 100 ㎚, preferably close to 10 nm in the range, the smaller the better.

The size of the first pores can be obtained in the range of several tens of nanometers to several micrometers by coating with thermal spray coating of an iron-based amorphous alloy composition. When the size of the first pores is larger than the corresponding range, it becomes easier for foreign substances to penetrate into the first pores at the first interface, so that the effect of forming the coating layer may be reduced.

2 is a schematic diagram showing an increased penetration path of molten metal when forming a multilayered metal surface coating body having first and second surface coating layers. The second surface coating layer is formed on the first surface coating layer, and a first interface is formed between the first surface coating layer and the second surface coating layer.

The composition of the second surface coating layer is not limited, but may include a metal composition, and is preferably an alloy based on metal carbides such as tungsten (W), nickel (Ni), chromium (Cr), ceramic material, amorphous Alloys, Inconel, Timken heat-resistant alloys, or derivatives such as nickel, chromium, and zinc metals and their chromates may be used.

Ceramic materials may include silicate ceramics made by combining natural raw materials and alumina (aluminum oxide, aluminum silicate) or oxide ceramics based on aluminum oxide, zirconium oxide, aluminum titanate and metal oxides, and silicon carbide, silicon nitride. And ceramic materials such as non-oxide ceramics based on carbon, nitrogen and silicon compounds such as aluminum nitride.

The coating method of the second surface coating layer is not limited, and the same coating method as the first surface coating layer can be used, and preferably, plating, vapor deposition, thermal spray coating, oxidation, painting, surface hardening, chemical conversion treatment, lining, etc. Can be used.

The second surface coating layer may be formed to have a uniform thickness on the first surface coating layer, and the thickness may be in the range of 0.01 μm to 3 mm, preferably 0.1 μm to 300 μm.

Ideally, the porosity of the second surface coating layer is 0% or close thereto, but the second pores may be included in the surface coating layer in the actual coating process. The fine second pores formed can be connected inside the second surface coating layer to penetrate the second surface coating layer, and form a path through which the fluid in contact with the surface coating layer can proceed, so the lower the porosity, the more the fluid penetrates. It may have a good effect to prevent it.

The porosity of the second surface coating layer may vary depending on the composition and coating method constituting the coating layer, and even when the same composition and coating method are used, the porosity may vary depending on the experimental conditions and equipment.

The second surface coating layer may be formed by selecting a composition and a coating method such that no pores exist or the porosity of the second surface coating layer exceeds 0% and is 10% or less. It is better to exceed% and less than 1%.

As a coating method, methods such as plating, vapor deposition, thermal spray coating, oxidation, painting, surface hardening, chemical treatment, lining, etc. can be used.The porosity according to the coating method is the temperature during the coating process, the speed of the coating, the temperature during the coating process, It is affected by the size of particles used for coating, and the porosity may be low in oxidation, surface hardening, plating, deposition, chemical conversion, thermal spray coating, etc., and porosity may be high in painting and lining. In the coating method shown as an example, the porosity according to the coating method may appear low in the order of oxidation, surface hardening, plating, deposition, chemical conversion, thermal spray coating, painting, and lining. It is preferable to use plating or thermal spray coating to form the second surface coating layer.

The porosity of the second surface coating layer may be lower than or equal to the porosity of the first surface coating layer. Since the second surface coating layer is located above the first surface coating layer and contacts the molten metal earlier, when the porosity of the second surface coating layer is lower than that of the first surface coating layer, the effect of delaying the penetration of molten metal of the metal surface coating body is high, The durability of the first surface coating layer and the life of the metal base material may be further extended.

The effect of delaying penetration of molten metal is that two different coating layers are formed through processes that ensure economic efficiency at a level that can secure industrial productivity in the physical coating layer, and pores generated in the process of forming these coating layers are at the interface. By being formed at different locations, it can be obtained by increasing the length of the path through which the molten metal physically penetrates, thereby improving the durability of the coating layer. In addition, when the second surface coating layer is formed with respect to the pores generated on the surface when the first surface coating layer is formed, along with the formation of the coating layer having pores formed at different positions, the pores of the first surface coating layer are reduced to the second surface coating layer. Since the particles can be blocked or blocked, the number of points at which the first surface coating layer can start permeation when the molten metal permeates can be relatively reduced, resulting in a higher penetration delay effect.

The size of the second pores may be in the range of tens nm to tens of µm, and may be formed in the range of 10 ㎚ to 50 µm or 10 ㎚ to 100 ㎚. C. The size of the second pores can be preferably obtained in the range of several tens of nm to 1 µm through the processes of plating, vapor deposition, and thermal spray coating. If the size of the second pore is out of the corresponding range, it becomes easier for foreign substances to penetrate the second pore, so that the effect may be reduced. As the size of the second pore is smaller than that of the first pore, the effect of delaying penetration is higher.

In the relationship between the second surface coating layer and the first surface coating layer, the porosity is preferably small or the same in the second surface coating layer, and the pore size is also preferably small or the same in the second surface coating layer. As the size of the pores increases, the porosity increases and the penetration of foreign substances becomes easier. Therefore, even in the case of the same porosity, when the average size of the pores is small, the effect of blocking penetration of foreign substances may be good. When the pore size is large, the path through the surface coating layer is simplified and the path is shortened. However, when the pore size is small, the optical path formed in the surface coating layer may become complicated, making it easy to block penetration.

The first interface is formed between the first surface coating layer and the second surface coating layer, and as shown in FIG. 2, the first interface may serve to delay the penetration time by extending the penetration path of the molten metal. When molten metal penetrates from the outside of the second surface coating layer to the base material, a section in which the first and second pores are not directly connected is included in the first interface where the first surface coating layer and the second surface coating layer are in contact. A penetration path connecting the path passing through the pores and the path passing through the second pore may be formed.

The penetration path includes a path passing through the second pores of the second surface coating layer, includes a path passing through the first pores in the first surface coating layer, and includes a path passing through the first interface. The path passing through the first interface includes a path connecting the first pores and the second pores along the first interface at the first interface, and a path not passing through the inside of the first surface coating layer and the inside of the second surface coating layer. Includes.

There may be one or more penetration paths, and may include a plurality of paths through the first pore, through the first interface, and through the second pore, but the path through the first pore and the second pore in one penetration route. It is preferable that the passing path is included one by one.

Since the penetration path includes a path connecting the first pore and the second pore at the first interface, the entire penetration path is extended.

The probability that the first pores present in the first surface coating layer and the second pores present in the second surface coating layer are directly connected between different first and second surface coating layers is very low. When the probability of connecting the pores of each surface coating layer at the first interface is calculated from the porosity of the first and second surface coating layers, it is in the range of 0.1% to 10%. In this case, the probability is the probability that the pores and pores can be connected to each other at the first interface, and assuming that all pores present at the interface do not penetrate the surface coating layer, the pores at this time are the first and second surface coating layers. Since non-penetrating pores are included, the probability that the first and second pores penetrating the first and second surface coating layers are connected to each other is lower than this, and may exceed 0% and be 0.1% or less.

The first pores and the second pores may respectively pass through the first and second surface coating layers and lead to the first interface, and the average distance of the path connecting the first pores and the second pores from the first interface along the first interface is It may be 1 μm to 30 μm, preferably 15 μm to 30 μm. The average distance of a path connecting the first pores and the second pores along the first interface at the first interface may be 0.1 to 100 times the thickness of the metal surface coating body. The average distance of a path connecting the first pores and the second pores along the first interface at the first interface may be 1.1 to 2 times greater than the penetration path in a single surface coating layer in which no interface is formed.

The average distance of the paths connecting the first pores and the second pores along the first interface at the first interface may be 0.1 to 10 times the average distance of the paths passing through the first pores in the first surface coating layer.

The second pores may be formed at a position different from the first pores on the first interface between the first surface coating layer and the second surface coating layer. When the first pore and the second pore are not directly connected, the molten metal that has penetrated the second pore reaches the first interface and moves along the first interface, and the molten metal that has penetrated is transferred to the first interface. Penetration proceeds in the interfacial direction (tangential direction), not the parent material direction (diameter direction), to the first pores of the surface coating layer or the defective part of the surface treatment. In this process, the tangential penetration path that occurs at the interface is relatively longer compared to the radial penetration path that occurs in the inner pores of the first and second surface coating layers, and the molten metal that has penetrated through the second pore is in the direction of the first pore. It does not move in the interfacial direction only, but moves randomly.

The movement of the molten metal at the interface relatively reduces the possibility of selecting a path from the second pore to the first pore, thereby exhibiting a delay effect of the penetration time. Due to the extension of the penetration path, the time taken for the molten metal to penetrate from the outside of the second surface coating layer to contact the base material through the first pores is delayed, so that the life of the base material is improved.

In order to increase the radial penetration path, there is a limitation in that the thickness of the entire metal surface coating body must be increased, but the tangential penetration path can be increased by forming the metal surface coating body to include an interface.

In addition, while the radial penetration is easy for the molten metal to penetrate in the moving direction, the tangential penetration at the interface allows the molten metal to spread widely along the two-dimensional interface. It is also possible to obtain an effect of reducing the decrease in the diametrical penetration rate in the first surface coating layer compared to the diametrical penetration rate of.

Another aspect of the present invention is a metal surface coating body including a third surface coating layer formed on the second surface coating layer.

The composition of the third surface coating layer is not limited, but a composition that can be used for the first surface coating layer or the second surface coating layer including a metal composition may be used. The coating method of the third surface coating layer is not limited, and a coating method that can be used for the first surface coating layer or the second surface coating layer may be used.

The third surface coating layer may be formed with a uniform thickness on the second surface coating layer, and the thickness may be in the range of 0.01 μm to 3 mm, preferably 0.1 μm to 300 μm.

The porosity of the third surface coating layer is preferably 0% or close thereto, but the third pores may be included in the surface coating layer in the actual coating process. The formed fine third pores are connected so as to pass through the third surface coating layer inside the third surface coating layer, penetrate through the third surface coating layer, and the second interface, which is the upper surface of the third surface coating layer and the lower surface in contact with the second surface coating layer. It can be formed to connect.

The porosity of the third surface coating layer varies depending on the composition and coating method constituting the coating layer, and even when the same composition and coating method are used, it may appear different according to the experimental conditions and equipment.

The third surface coating layer may be formed by selecting a composition and a coating method such that no pores exist or the porosity of the third surface coating layer exceeds 0% and is 10% or less. It is better to exceed% and less than 1%.

The porosity of the third surface coating layer may be lower than or equal to the porosity of the second surface coating layer. Since the third surface coating layer is located above the second surface coating layer and contacts the molten metal earlier, when the porosity of the third surface coating layer is lower than that of the second surface coating layer, the effect of delaying the penetration of molten metal into the metal surface coating body is high, The durability of the first surface coating layer and the life of the metal base material may be further extended.

The second interface is formed between the second surface coating layer and the third surface coating layer and serves to delay penetration by further extending the penetration path of the molten metal.

The probability that the second pores present in the second surface coating layer and the third pores present in the third surface coating layer are directly connected at the second interface is very low, and the probability is calculated from the porosity of the second surface coating layer and the third surface coating layer. And the range is calculated in the same way as the probability that the first pore and the second pore are directly connected.

The average distance between the second and third pores at the second interface can be calculated in the same way as the average distance between the first and second pores, and the second and third pores are separated from the second interface along the second interface. The average distance of the connecting path may be 1 μm to 30 μm, and preferably 15 μm to 30 μm. The average distance of a path connecting the third pores and the second pores along the second interface at the second interface may be 0.1 to 100 times the thickness of the metal surface coating body. The average distance of a path connecting the third pores and the second pores along the second interface at the second interface may be 1.1 to 2 times the penetration path distance in a single surface coating layer in which no interface is formed.

The average distance of a path connecting the third pores and the second pores along the second interface at the second interface may be 0.1 to 10 times the average distance of a path passing through the second pores in the second surface coating layer.

The second interface is located above the first interface, and the second surface coating layer and the third surface coating layer adjacent to the second interface may have a lower porosity than the first and second surface coating layers adjacent to the first interface. The anti-metal effect may be better than that of the first interface.

As the penetration path of molten metal increases, the distance between the third pore through which molten metal flows from the surface of the outermost surface coating layer (third surface coating layer) and the end of the penetration path increases, and the ends of the penetration path are dispersed in various directions. Therefore, the penetration rate of molten metal at the end of one penetration path is reduced. In addition, the movement path of the molten metal in the direction of the interface connecting the second pores and the third pores is lengthened, resulting in a decrease in the penetration rate.

Another aspect of the present invention is a metal surface coating body comprising a plurality of surface coating layers. The metal surface coating body includes a first surface coating layer formed on the surface of the base material, and includes an n-th surface coating layer formed on the (n-1)th surface coating layer for a natural number n of 2 or more and 5 or less, and the n-th surface An (n-1)th interface is formed between the coating layer and the (n-1)th surface coating layer.

The composition of the n-th surface coating layer is not limited, but may include a metal composition, and preferably, an alloy based on metal carbides such as tungsten (W), nickel (Ni), chromium (Cr), and natural raw materials. Silicate ceramics made by combining alumina (aluminum oxide, aluminum silicate) / oxide ceramics based on aluminum oxide, zirconium oxide, aluminum titanate and metal oxides / carbon, nitrogen and silicon compounds such as silicon carbide, silicon nitride and aluminum nitride A ceramic material such as non-oxide ceramics based on nickel, which is a heat-resistant alloy containing 15% chromium, 6-7% iron, 2.5% titanium, and 1% or less aluminum, manganese, and silicon. Inconel, iron-based amorphous alloy with iron/zirconium/titanium/aluminum as the main material / zirconium-based amorphous alloy / titanium-based amorphous alloy / aluminum-based amorphous alloy, etc. can be used. ,Timken heat-resistant alloy containing 20-27% nickel, 5-7% molybdenum, 2% manganese, and 1% silicon, nickel/chromium/zinc metal and derivatives such as chromate, etc. can be used. It may be formed by including the same composition as the composition of the surface coating layer.

The coating method of the n-th surface coating layer is not limited, and the same coating method as the first surface coating layer can be used, preferably plating, vapor deposition, thermal spray coating, oxidation, painting, surface hardening, chemical conversion, lining, etc. The porosity according to the coating method is affected by the temperature during the coating process, the speed of the coating, the temperature during the coating process, and the size of the particles used for the coating. Porosity may be low in the back, and porosity may be high in painting and lining.

In the coating method shown as an example, the porosity according to the coating method may appear low in the order of oxidation, surface hardening, plating, deposition, chemical conversion, thermal spray coating, painting, and lining. It is preferable to use plating or thermal spray coating to form the second surface coating layer.

The n-th surface coating layer may be formed to have a uniform thickness on the second surface coating layer, and the thickness may be in the range of 0.01 μm to 3 mm, preferably 0.1 μm to 300 μm. The thickness of the n-th surface coating may vary depending on the number of surface coating layers included in the entire metal surface coating body, and as the number of coatings increases, the thickness of the n-th surface coating further decreases to form a range of 0.1 μm to 200 μm. have.

The thickness of the metal surface coating body may be 0.1 μm to 10 mm, preferably 0.1 μm to 2 mm. If the thickness of the metal surface coating body is thinner than the applicable range, molten metal is likely to penetrate due to pores or cracks, and durability and abrasion resistance are reduced, so that cracks are likely to occur afterwards due to external shock or vibration. In addition, it is difficult to increase the number of surface coating layers, making it difficult to sufficiently obtain the effects of the present invention, and when the thickness is thicker than the range, the amount of coating material is increased, resulting in low economic efficiency, and the adhesion is weakened, causing the coating layer to fall off due to external impact. There is this.

The n-th surface coating layer may include at least one or more n-th pores therein, and has an n-th porosity. The n-th surface coating layer may be formed by selecting a composition and a coating method such that no pores exist or the porosity of the n-th surface coating layer exceeds 0% and is 10% or less. It is better to exceed% and less than 1%. The nth porosity may be less than or equal to the (n-1)th porosity. The size of the n-th pores may be in the range of tens nm to several tens µm, and may be formed in the range of 10 ㎚ to 50 µm or 10 ㎚ to 100 ㎚. The smaller the size of the nth pores than the size of the (n-1)th pores, the higher the effect of delaying penetration of the metal surface coating body.

When the nth surface coating layer is formed by the same coating method using the same composition as the adjacent (n-1)th coating layer, the properties of the two adjacent surface coating layers at the (n-1)th interface are similar, so that the composition or coating method is not The effect of the invention may not be sufficiently obtained compared to the interface of the other two surface coating layers. It is difficult to form an interface because the interface formed by the two surface coating layers having the same properties has less difference in surface energy than the interface formed by the two surface coating layers having different properties. It can be seen that when pores are continuously connected in the nth coating layer and foreign substances such as molten metal penetrate, the connected pores serve as a passage for the movement of foreign substances.

The nth surface coating layer may be formed of a composition different from the adjacent (n-1)th coating layer, may be formed by a different coating method than the adjacent coating layer, and may be formed by a different coating method using a different composition.

The n-th surface coating layer may be formed by the same coating method as at least one of the first surface coating layer to the (n-1)-th surface coating layer. In addition, the type of composition constituting the metal surface coating body is n types or less with respect to the first surface coating layer to the n-th surface coating layer, and may be (n-1) types or less, and the n-th surface coating layer is the first surface coating layer to the first surface coating layer. (n-1) It may be formed of the same composition as at least one of the surface coating layers.

When the metal surface coating body is made of n layers, fewer (n-1) interfaces than the number of coating layers may be formed. The (n-1)th interface can be distinguished according to the composition and coating method of the (n-1)th surface coating layer and the nth surface coating layer adjacent at the top and bottom, and only the order of the top and bottom surface coating layers is changed. Can be seen as the same interface. That is, as the interface between the A layer and the B layer, when the layer A is lower and the layer B is upper and the layer B is lower and the layer A is upper, the two interfaces are the same.

For example, in the case of forming the same composition of the (n-2)th surface coating layer and the nth surface coating layer for 3 or more n by the same coating method, the (n-1)th interface is the (n-1)th surface coating layer and It is formed between the nth surface coating layer, and the (n-2)th interface is formed between the (n-1)th surface coating layer and the (n-2)th surface coating layer. The n-2) interface can be seen as an interface with the same properties.

At this time, the (n-1)th interface and the (n-2)th interface are interfaces having the same properties, but the (n-1)th and (n-2)th pores are not connected to each other, and an external substance A path that must move through the interface is added at the time of penetration, resulting in the effect of delaying the penetration rate of the molten metal.

The number of interfaces included in the metal surface coating body is not limited, but the metal surface coating body may include two or more interfaces having the same properties.

The metal surface coating body may not include a bonding layer for improving the adhesion of the n-th surface coating layer. The bonding layer is less effective in preventing the penetration of liquid through the existing interface due to improved bonding strength with the adjacent coating layer, making it difficult to achieve the object of the present invention.

In order to achieve the object of the present invention, the multilayer coating structure of the metal surface coating body is preferably formed to minimize the porosity of the surface coating layer while the number of interfaces formed between adjacent surface coating layers is large.

The metal surface coating body, an aspect of the present invention, has the following advantageous effects by the number of interfaces and porosity of the entire metal surface coating body, and the coincidence ratio of pores at the interface, regardless of characteristics such as electrical properties or magnetic properties of each coating layer. There are features that can be obtained.

Hereinafter, the present invention will be described in detail with reference to specific examples.

Example

Example 1

A sample was prepared by thermal spray coating with TaeguTec's tungsten carbide powder (WC250H) on a 10cm x 10cm carbon steel specimen.

For the thermal spray coating, the first surface coating layer was formed so that the coating layer of tungsten carbide powder was 50㎛ by using a TAFA Model 8200 gun and a TAFA Model 1288 Powder Feeder on Praxair JP8000 equipment.

A second surface coating layer was formed on the first surface coating layer so that the iron-based amorphous alloy powder (AA02) of Atometal Tech Korea was spray-coated using the same equipment, and the porosity was the same as that of the first surface coating layer and the coating layer was 50 μm.

Example 2

The same tungsten carbide powder as in Example 1 was spray-coated to form a 33 µm first surface coating layer, and the same iron-based amorphous alloy as in Example 1 was spray-coated to form a 33 µm second surface coating layer. By thermal spraying, a 33 µm third surface coating layer having the same porosity as the second surface coating layer was formed.

Example 3

The same tungsten carbide was spray-coated to form a 25 µm first surface coating layer and a third surface coating layer, and the same iron-based amorphous alloy was spray-coated to form a 25 µm second surface coating layer and a fourth surface coating layer.

Example 4

The same tungsten carbide was spray coated to form a first surface coating layer of 50 μm, and a second surface coating of 50 μm was formed by hard chromium electroplating.

Example 5

The same tungsten carbide powder was spray-coated to form a 33 µm first surface coating layer, and a 33 µm second surface coating layer was formed by the same hard chromium electroplating as in Example 4, and the same tungsten carbide was spray-coated to form a 33 µm layer. A third surface coating layer was formed.

Example 6

The same tungsten carbide powder was spray-coated to form a 33 µm first surface coating layer, and a 33 µm second surface coating layer was formed by the same hard chromium electroplating as in Example 4, and an iron-based amorphous alloy powder was spray-coated to 33 µm. A third surface coating layer was formed.

Example 7

The same tungsten carbide powder was spray-coated to form a 50 µm first surface coating layer, and the same tungsten carbide powder was electroplated to form a 50 µm second surface coating layer.

Example 8

A first surface coating layer and a second surface coating layer having the same composition as in Example 7 were formed to have a thickness of 33 μm, and a third surface coating layer having a lower porosity than the second surface coating layer was formed by thermal spray coating with tungsten carbide powder.

Example 9

The first surface coating layer, the second surface coating layer, and the third surface coating layer having the same composition as in Example 8 were each formed to have a thickness of 25 μm, and a fourth surface of 25 μm having a lower porosity than the third surface coating layer by electroplating tungsten carbide powder. A coating layer was formed.

Example 10

Under the same conditions as in Example 1, the same tungsten carbide powder was spray-coated to form a 75 µm first surface coating layer, and the same iron-based amorphous alloy powder was spray-coated to form a 75 µm second surface coating layer.

Example 11

Under the same conditions as in Example 1, the same tungsten carbide powder was spray coated to form a first surface coating layer of 85 μm, and the same iron-based amorphous alloy powder was spray coated to form a second surface coating layer of 15 μm.

Example 12

Under the same conditions as in Example 1, the same tungsten carbide powder was spray-coated to form a 15 µm first surface coating layer, and the same iron-based amorphous alloy powder was spray-coated to form a 85 µm second surface coating layer.

Example 13

The same surface coating layer as in Example 2 was formed, and the surface coating layer formed on the upper portion of each surface coating layer was formed to have a lower porosity than the lower surface coating layer.

Example 14

The same surface coating layer as in Example 5 was formed, and the surface coating layer formed on the upper portion of each surface coating layer was formed to have a lower porosity than that of the lower surface coating layer.

Example 15

The same surface coating layer as in Example 8 was formed, and the surface coating layer formed on the upper portion of each surface coating layer was formed to have a lower porosity than the lower surface coating layer.

The composition, coating method, and thickness of the surface coating layer of Examples 1 to 15 are summarized in Table 1 below and shown.

1st surface coating layer 2nd surface coating layer 3rd surface coating layer 4th surface coating layer Composition Coating method Thickness(㎛) Composition Coating method Thickness(㎛) Composition Coating method Thickness(㎛) Composition Coating method Thickness(㎛) Example 1 Tungsten carbide Thermal spray coating 50 Iron-based amorphous alloy Thermal spray coating 50 Example 2 Tungsten carbide Thermal spray coating 33 Iron-based amorphous alloy Thermal spray coating 33 Tungsten carbide Thermal spray coating 33 Example 3 Tungsten carbide Thermal spray coating 25 Iron-based amorphous alloy Thermal spray coating 25 Tungsten carbide Thermal spray coating 25 Iron-based amorphous alloy Thermal spray coating 25 Example 4 Tungsten carbide Thermal spray coating 50 Hard chrome Electroplating 50 Example 5 Tungsten carbide Thermal spray coating 33 Hard chrome Electroplating 33 Tungsten carbide Thermal spray coating 33 Example 6 Tungsten carbide Thermal spray coating 33 Hard chrome Electroplating 33 Iron-based amorphous alloy Thermal spray coating 33 Example 7 Tungsten carbide Thermal spray coating 50 Tungsten carbide Electroplating 50 Example 8 Tungsten carbide Thermal spray coating 33 Tungsten carbide Electroplating 33 Tungsten carbide Thermal spray coating 33 Example 9 Tungsten carbide Thermal spray coating 25 Tungsten carbide Electroplating 25 Tungsten carbide Thermal spray coating 25 Tungsten carbide Electroplating 25 Example 10 Tungsten carbide Thermal spray coating 75 Iron-based amorphous alloy Thermal spray coating 75 Example 11 Tungsten carbide Thermal spray coating 85 Iron-based amorphous alloy Thermal spray coating 15 Example 12 Tungsten carbide Thermal spray coating 15 Iron-based amorphous alloy Thermal spray coating 85 Example 13 Tungsten carbide Thermal spray coating 33 Iron-based amorphous alloy Thermal spray coating 33 Tungsten carbide Thermal spray coating 33 Example 14 Tungsten carbide Thermal spray coating 33 Hard chrome Electroplating 33 Tungsten carbide Thermal spray coating 33 Example 15 Tungsten carbide Thermal spray coating 33 Tungsten carbide Electroplating 33 Tungsten carbide Thermal spray coating 33

Comparative example

Comparative Example 1

The same tungsten carbide powder as in Example 1 was spray-coated to form a first surface coating layer having a thickness of 50 μm, and a second surface coating layer having the same thickness and thickness was formed.

Comparative Examples 2 to 4

The same tungsten carbide powder as in Example 1 was spray-coated to form a first surface coating layer having a thickness of 30 µm, 50 µm, and 100 µm, respectively.

Comparative Examples 5 to 7

The same iron-based amorphous alloy powder as in Example 1 was spray-coated to form a first surface coating layer having a thickness of 30 μm, 50 μm, and 100 μm, respectively.

Comparative Examples 8 to 10

Hard chromium electrolytic plating was performed on the base material to form a first surface coating layer having a thickness of 30 µm, 50 µm, and 100 µm, respectively.

Comparative Example 11

While forming the same coating layer as in Example 1, a coating was formed so that the porosity of the second surface coating layer was greater than 0.6%.

Comparative Example 12

Under the same conditions as in Example 1, the same tungsten carbide powder was spray-coated to form a 97 µm first surface coating layer, and the same iron-based amorphous alloy powder was spray-coated to form a 3 µm second surface coating layer.

Comparative Example 13

Under the same conditions as in Example 1, the same tungsten carbide powder was spray-coated to form a 3 µm first surface coating layer, and the same iron-based amorphous alloy powder was spray-coated to form a 97 µm second surface coating layer.

Comparative Example 14

The same surface coating layer as in Example 2 was formed, and when each surface coating layer was formed, the surface coating layer formed on the upper side was formed to have a higher porosity than the lower surface coating layer.

Comparative Example 15

The same surface coating layer as in Example 5 was formed, and when each surface coating layer was formed, the surface coating layer formed on the upper side was formed to have a higher porosity than the lower surface coating layer.

Comparative Example 16

The same surface coating layer as in Example 8 was formed, and the surface coating layer formed on the upper portion of each surface coating layer was formed to have a higher porosity than that of the lower surface coating layer.

The composition, coating method, and thickness of the surface coating layer of Comparative Examples 1 to 16 are summarized in Table 2 below.

1st surface coating layer 2nd surface coating layer 3rd surface coating layer Composition Coating method thickness
(㎛) Composition Coating method Thickness(㎛) Composition Coating method thickness
(㎛) Comparative Example 1 Tungsten carbide Thermal spray coating 50 Tungsten carbide Thermal spray coating 50 Comparative Example 2 Tungsten carbide Thermal spray coating 30 Comparative Example 3 Tungsten carbide Thermal spray coating 50 Comparative Example 4 Tungsten carbide Thermal spray coating 100 Comparative Example 5 Iron-based amorphous alloy Thermal spray coating 30 Comparative Example 6 Iron-based amorphous alloy Thermal spray coating 50 Comparative Example 7 Iron-based amorphous alloy Thermal spray coating 100 Comparative Example 8 Hard chrome Electroplating 30 Comparative Example 9 Hard chrome Electroplating 50 Comparative Example 10 Hard chrome Electroplating 100 Comparative Example 11 Tungsten carbide Thermal spray coating 50 Iron-based amorphous alloy Thermal spray coating 50 Comparative Example 12 Tungsten carbide Thermal spray coating 97 Iron-based amorphous alloy Thermal spray coating 3 Comparative Example 13 Tungsten carbide Thermal spray coating 3 Iron-based amorphous alloy Thermal spray coating 97 Comparative Example 14 Tungsten carbide Thermal spray coating 33 Iron-based amorphous alloy Thermal spray coating 33 Tungsten carbide Thermal spray coating 33 Comparative Example 15 Tungsten carbide Thermal spray coating 33 Hard chrome Electroplating 33 Tungsten carbide Thermal spray coating 33 Comparative Example 16 Tungsten carbide Thermal spray coating 33 Tungsten carbide Electroplating 33 Tungsten carbide Thermal spray coating 33

Experimental example

After measuring the porosity (%) of the sample specimens according to Examples 1 to 12 and Comparative Examples 1 to 13, a zinc specimen having a thickness of 3 mm and a size of 1 cm x 1 cm was placed on the coated specimen, and in an oven at a temperature of 600° C. It was left for 1 hour.

After cooling the specimen out of the oven to room temperature, polish the coating layer using a specimen grinder (Nanotech NA-P2000N), and analyze the upper portion of the carbon steel specimen by SEM-EDS (Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy) to obtain zinc. The number of spots to be detected was recorded.

For Examples 13 to 15 and Comparative Examples 14 to 16, the porosity was measured and recorded after the formation of each surface coating layer, respectively, and the experiment time in the oven was changed from 1 hour to 2 hours, and the same procedure was performed.

Experimental Example 1

The porosity of the sample specimen of Example 1 was measured to obtain a porosity of 0.6%. Four spots where zinc was detected were found and recorded.

Experimental Example 2

As a result of the sample experiment of Example 2, the porosity was 0.6%, and the zinc detection sites were 2 locations.

Experimental Example 3

As a result of the sample experiment of Example 3, the porosity was 0.6% and the zinc detection site was 0.

Experimental Example 4

As a result of the sample experiment of Example 4, the porosity was 0.3%, and the zinc detection sites were 3 locations.

Experimental Example 5

As a result of the sample experiment of Example 5, the porosity was 0.4% and the zinc detection site was 0.

Experimental Example 6

As a result of the sample experiment of Example 6, the porosity was 0.3% and the zinc detection site was 0.

Experimental Example 7

As a result of the sample experiment of Example 7, the porosity was 0.6%, and the zinc detection sites were 4 locations.

Experimental Example 8

As a result of the sample experiment of Example 8, the porosity was 0.4% and the zinc detection site was 0.

Experimental Example 9

As a result of the sample experiment of Example 9, the porosity was 0.3% and the zinc detection site was 0.

Experimental Example 10

As a result of the sample experiment of Example 10, the porosity was 0.7%, and the zinc detection sites were 2 locations.

Experimental Example 11

As a result of the sample experiment of Example 11, the porosity was 0.7%, and the zinc detection sites were 3 locations.

Experimental Example 12

As a result of the sample experiment of Example 12, the porosity was 0.7%, and the zinc detection sites were 3 locations.

Experimental Example 13

As a result of the sample experiment of Example 13, the porosity of the surface coating layer was 0.6, 0.2, and 0.08% in the order of the first surface coating layer to the third surface coating layer, respectively, and the zinc detection site was 0.

Experimental Example 14

As a result of the sample experiment of Example 14, the porosity of the surface coating layer was 0.5, 0.2, and 0.1%, respectively, in the order of the first surface coating layer and the third surface coating layer, and the zinc detection site was 0.

Experimental Example 15

As a result of the sample experiment of Example 15, the porosity of the surface coating layer was 0.3, 0.1, and 0.06% in the order of the first surface coating layer to the third surface coating layer, respectively, and the zinc detection site was 0.

Experimental Example 16

As a result of the sample experiment of Comparative Example 1, the porosity was 0.7%, and the zinc detection sites were 24 locations.

Experimental Examples 17 to 19

As a result of the sample experiments of Comparative Examples 2 to 4, the porosity was 0.8%, 0.8%, and 0.7%, respectively, and the zinc detection sites were 17, 15, and 13, respectively.

Experimental Examples 20 to 22

As a result of the sample experiments of Comparative Examples 5 to 7, the porosity was 0.6%, 0.5%, and 0.5%, and the zinc detection sites were 17, 12, and 11, respectively.

Experimental Examples 23 to 25

As a result of the sample experiments of Comparative Examples 8 to 10, the porosity was 0.5%, 0.5%, and 0.6%, and the zinc detection sites were 16, 13, and 12, respectively.

Experimental Example 26

As a result of the sample experiment of Comparative Example 11, the porosity was 1.5%, and the zinc detection sites were 17 locations.

Experimental Example 27

As a result of the sample experiment of Comparative Example 12, the porosity was 1.4%, and the zinc detection sites were 19 locations.

As a result of the sample experiment of Comparative Example 12, the porosity was 0.7%, and the zinc detection sites were 9 locations.

Experimental Example 28

As a result of the sample experiment of Comparative Example 13, the porosity was 1.6%, and the zinc detection sites were 21 locations.

As a result of the sample experiment of Comparative Example 13, the porosity was 0.7%, and the zinc detection sites were 10 locations.

Experimental Example 29

The sample of Comparative Example 14 was measured for porosity at the time of formation of each surface coating layer, and the experiment was performed by changing the time of the oven left experiment to 2 hours. As a result of the experiment, the porosity of the surface coating layer was 0.6, 0.8, and 1.1% in order from the first surface coating layer to the third surface coating layer, respectively, and there were 16 zinc detection sites.

Experimental Example 30

The sample of Comparative Example 15 was tested in the same manner as in Experimental Example 29. As a result of the experiment, the porosity of the surface coating layer was 0.5, 0.8, and 1.0% in order from the first surface coating layer to the third surface coating layer, respectively, and there were 15 zinc detection sites.

Experimental Example 31

The sample of Comparative Example 16 was tested in the same manner as in Experimental Example 29. As a result of the experiment, the porosity of the surface coating layer was 0.5, 0.6, and 1.1% in order from the first surface coating layer to the third surface coating layer, respectively, and there were 17 zinc detection sites.

The porosity and the number of zinc detection sites of Experimental Examples 1 to 31 are summarized and shown in Table 3 below.

Measurement target Porosity Zinc detection
Part (dog) Measurement target Porosity Zinc detection
Part (dog) Experimental Example 1 0.6% 3 Experimental Example 16 0.7% 13 Experimental Example 2 0.6% One Experimental Example 17 0.7% 24 Experimental Example 3 0.6% 0 Experimental Example 18 0.8% 17 Experimental Example 4 0.3% 3 Experimental Example 19 0.8% 15 Experimental Example 5 0.4% 0 Experimental Example 20 0.6% 17 Experimental Example 6 0.3% 0 Experimental Example 21 0.5% 12 Example 7 0.6% 4 Experimental Example 22 0.5% 11 Experimental Example 8 0.4% One Experimental Example 23 0.5% 16 Experimental Example 9 0.3% 0 Experimental Example 24 0.5% 13 Experimental Example 10 0.7% 2 Experimental Example 25 0.6% 12 Experimental Example 11 0.7% 3 Experimental Example 26 1.5% 17 Experimental Example 12 0.7% 3 Experimental Example 27 0.7% 9 Experimental Example 13 0.6%
0.2%
0.08% 0 Experimental Example 28 0.7% 10 Experimental Example 14 0.5%
0.2%
0.1% 0 Experimental Example 29 0.6%
0.8%
1.1% 16 Experimental Example 15 0.3%
0.1%
0.06% 0 Experimental Example 30 0.5%
0.8%
1.0% 15 Experimental Example 31 0.5%
0.6%
1.1% 17

Looking at the results of Experimental Examples 1 to 6 in Table 3, there was an effect of preventing the penetration of molten metal according to an increase in the number of interfaces when forming a surface coating layer in which at least one of the composition or coating method is formed differently.

In the results of Experimental Examples 7 to 9, when a surface coating layer having the same composition and a different coating method was used, the penetration of molten metal was prevented as the number of interfaces increased.

In the results of Experimental Example 16, it was found that the effect of the invention was relatively small when the same composition was formed by the same coating method.

In the experiments of Experimental Examples 13 to 15, the lower the porosity of the surface coating layer formed thereon, the better the molten metal blocking effect could be obtained.

Features, structures, effects, and the like illustrated in each of the above-described embodiments may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

1: first surface coating layer 2: second surface coating layer
3: first interface 10: base material
20: molten metal

Claims (14)

Base material;
A first surface coating layer formed on the base material and having at least one or more first pores penetrating the inside; And
It is provided on the first surface coating layer, and includes a second surface coating layer in which at least one or more second pores penetrating the inside are formed,
A metal surface coating body comprising a section in which the first pores and the second pores are not directly connected at a first interface between the first surface coating layer and the second surface coating layer. The method of claim 1,
Metal surface coating body including a path through the first pore, the first interface, and the second pore when a foreign material penetrates from the outside of the second surface coating layer to the base material through the second pore . The method of claim 2,
A metal surface coating body in which a penetration path connecting a path passing through the first pore and a path passing through the second pore is formed on the first interface. The method of claim 3,
A metal surface coating body having a first porosity of the first surface coating layer exceeding 0% and not exceeding 10%. The method of claim 4,
The second porosity of the second surface coating layer exceeds 0% and is 10% or less. The method of claim 5,
The second porosity is less than or equal to the first porosity of the metal surface coating body. The method of claim 6,
The diameter of the second pore is smaller than or equal to the diameter of the first pore. The method of claim 7,
The second surface coating layer is a metal surface coating body formed by differently from the first surface coating layer at least one or more of a composition and a coating method. The method of claim 8,
The thickness of the first surface coating layer is 0.01㎛ to 5mm metal surface coating body. The method of claim 9,
The thickness of the second surface coating layer is 0.01㎛ to 3㎜ metal surface coating body. The method of claim 10,
The metal surface coating body has a thickness of 0.1 μm to 10 mm. The method of claim 1,
It is provided on the second surface coating layer, and includes a third surface coating layer in which at least one or more third pores are formed,
The third surface coating layer is a metal surface coating body having a third porosity less than or equal to the second porosity of the second surface coating layer. The method of claim 12,
The third surface coating layer is a metal surface coating body formed by including the same composition as at least one of the first surface coating layer or the second surface coating layer. The method of claim 3,
The average distance of a path connecting the first pores and the second pores along the first interface at the first interface is 1 μm to 30 μm.

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