KR20210091007A - Method for thermal spray coating and apparatus for the same - Google Patents

Abstract

Various embodiments relate to a thermal spray coating method, wherein the thermal spray coating method forming a ferromagnetic metal coating layer on an aluminum base material which comprises: a step of preparing one surface of the base material where the coating layer is formed; a step of heating the other surface of the base material to enable the base material to reach predetermined temperature; and a step of forming the ferromagnetic coating layer on one surface of the base material maintained at the predetermined temperature. The present invention can prevent separation or a crack of the coating layer while sufficiently securing the thickness of the metal coating layer formed on the aluminum base material. Various other embodiments are possible.

Description

Thermal spray coating method and apparatus {METHOD FOR THERMAL SPRAY COATING AND APPARATUS FOR THE SAME}

Various embodiments to be described later relate to a thermal spray coating method and a thermal spray coating apparatus.

Thermal spraying is a technique for forming a film on a substrate by changing a powder or a linear material from a high-temperature heat source into molten droplets and collides with a substrate at high speed. In particular, thermal spray coating is used to improve heat resistance and durability of parts such as power plant turbines, ships, automobile engines, and space shuttles. As for coating technology, plasma spraying, flame spraying, HVOF (High Velocity Oxygen Fuel) spraying, arc spraying, etc. are known. Such thermal spray coating has the advantage of rapidly forming a film of various types of materials, such as metal, alloy, ceramic, plastic, and composite material, on the substrate.

On the other hand, induction is a heating appliance for cooking food by generating heat using electromagnetic force. In order to use an aluminum alloy cookware for induction, a ferromagnetic metal material such as steel is mainly coated on the bottom surface of the aluminum alloy cookware. The ferromagnetic metal coating layer formed on the bottom surface of the aluminum alloy cooking utensil increases the magnetic flux density of the electromagnetic force applied by induction in proportion to the thickness of the metal coating layer if the porosity in the tissue of the coating layer is similar, and increases the cooking temperature to a high temperature. can However, in general, it is known that it is very difficult to coat a metal material such as steel on aluminum by thermal spraying, and it is difficult to find a case of actually coating a steel material of 300 μm or more on aluminum for commercial use.

Figure 6a is a photograph in which a thermal spray coating of a steel material is formed on an aluminum base material in the prior art.

Referring to FIG. 6A , the thicker the film of the steel material formed on aluminum is, the more the coating layer falls off or cracks occur.

Various embodiments disclosed in this document may provide a thermal spray coating method and a thermal spray coating apparatus for forming a ferromagnetic metal coating layer on an aluminum base material.

In addition, various embodiments provide a thermal spray coating method and a thermal spray coating device in which a ferromagnetic metal coating layer having a thickness of 1.3 mm or more is directly formed on an aluminum base material without intervening other layers so that the aluminum cookware can be used under optimal conditions for induction. can provide

The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. There will be.

A thermal spray coating method according to various embodiments, for example, in the thermal spray coating method of forming a ferromagnetic metal coating layer on an aluminum base material, comprising the steps of: preparing one surface of the base material to form the coating layer; heating the other surface of the base material to bring the base material to a predetermined temperature; and forming the ferromagnetic metal coating layer on one surface of the base material maintained at the predetermined temperature.

In various embodiments, the forming of the ferromagnetic metal coating layer on one surface of the base material maintained at the predetermined temperature may include heating the other surface of the base material to maintain the base material at the predetermined temperature.

In various embodiments, the step of preparing one surface of the base material on which the coating layer is to be formed may include cleaning one surface of the base material, and blasting one surface of the base material.

In various embodiments, the method may further include cooling the base material on which the coating layer is formed.

In various embodiments, further comprising the step of measuring the temperature of the base material, the predetermined temperature may be included in the range of 180 to 300 ℃.

In various embodiments, the forming of the ferromagnetic metal coating layer on one surface of the preheated base material includes melting the ferromagnetic metal wire, and spraying the molten ferromagnetic metal particles on one surface of the base material may include.

In various embodiments, the coating layer may contain 97 wt% or more of Fe (pure iron).

In various embodiments, the coating layer may be formed on one surface of the base material with an average thickness of 1.3 mm to 2.5 mm.

In one embodiment, cooling the base material on which the coating layer is formed may include disposing a block bar on one surface and the other surface of the base material, and spraying the cooling air on one surface of the block bar.

A thermal spray coating apparatus according to various embodiments, for example, in a thermal spray coating apparatus for forming a ferromagnetic metal coating layer on an aluminum base material, melts the ferromagnetic metal wire, and applies the molten ferromagnetic metal particles to the base material. A thermal spray gun that sprays on one side; and a heater disposed on the other surface of the base material and heating the base material to a predetermined temperature.

In one embodiment, it may further include a block bar disposed in contact with the one surface and the other surface of the base material on which the coating layer is formed.

In various embodiments, the predetermined temperature may be included in the range of 180 to 300 ℃.

In various embodiments, the ferromagnetic metal wire may contain 97 wt% or more of Fe (pure iron).

In various embodiments, the thermal spray gun, a guide for guiding the ferromagnetic metal wire,

It may include a power supply unit for supplying electricity to the ferromagnetic metal wire, and a spraying part for spraying compressed air to the ferromagnetic metal wire melted by an electric arc generated by contact with the ferromagnetic metal wire supplied with electricity.

The thermal spray coating method and the apparatus according to various embodiments may form a ferromagnetic metal coating layer having a thickness of 1.3 mm or more on an aluminum base material without intervening another intermediate layer.

The thermal spray coating method and the apparatus according to various embodiments can prevent the coating layer from falling off or cracking while sufficiently securing the thickness of the metal coating layer formed on the aluminum base material.

Effects obtainable in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present disclosure belongs from the description below. will be.

1 is a flowchart of a thermal spray coating method according to various embodiments.
2 is a view showing a thermal spray coating method according to various embodiments.
3 is a side view showing a thermal spray coating apparatus according to various embodiments.
4 is a cross-sectional view of a thermal spray coating apparatus according to various embodiments.
5 is a top view of a thermal spray coating apparatus according to an embodiment.
Figure 6a is a photograph in which a thermal spray coating of a steel material is formed on an aluminum base material in the prior art.
6B is a photograph of an iron thermal spray coating layer formed on an aluminum base material by a thermal spray coating method according to various embodiments.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings.

The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of the embodiments. In connection with the description of the drawings, like reference numerals may be used for similar or related components. The singular form of the noun corresponding to the item may include one or more of the item, unless the relevant context clearly dictates otherwise. As used herein, "A or B", "at least one of A and B", "at least one of A or B," "A, B or C," "at least one of A, B and C," and "A , B, or C" each may include any one of the items listed together in the corresponding one of the phrases, or all possible combinations thereof. Terms such as “first”, “second”, or “first” or “second” may simply be used to distinguish the component from other such components, and refer to those components in other aspects (e.g., importance or order) is not limited.

1 is a flowchart of a thermal spray coating method according to various embodiments, and FIG. 2 is a diagram illustrating a thermal spray coating method according to various embodiments.

1 and 2, the thermal spray coating method according to various embodiments may form a thick ferromagnetic metal coating on one surface of the aluminum base material in order to reinforce the electromagnetic properties of the aluminum base material. Here, the ferromagnetic metal may be, for example, iron (Fe). The thermal spray coating method 100 according to various embodiments may include preparing a coating target surface of a base material 110 , heating the base material 120 , and forming a metal coating layer 130 .

The step 110 is a step of preparing a surface to be coated on which the metal coating layer 222 is to be formed on the aluminum base material 230 , that is, one surface of the aluminum base material. Step 110 may include cleaning one surface of the base material and blasting one surface of the base material. In the step of cleaning one surface of the base material, for example, heat is applied to the base material to dissolve contaminants, or grease may be applied to remove oleaginous contaminants. The first picture of FIG. 2 is a picture taken after washing one side of the base material. The step of blasting one surface of the base material may include spraying an abrasive on one surface of the aluminum base material to remove oxides generated on the one surface and adjust the surface roughness of the one surface to increase the surface area of the one surface. The second picture of FIG. 2 is a picture taken after blasting one side of the base material.

The step 110 may further include a step of masking in order to partition a portion on which a coating layer is to be formed among one surface of the aluminum base material. In the masking step, a part on which a thermal spray coating layer is to be formed among one surface of the base material may be manufactured as a mask, and the mask may be adhesively disposed on one surface of the base material.

The step 120 is a step of heating the other surface of the aluminum base material to reach a predetermined temperature. In step 120, to increase the adhesion of the ferromagnetic metal particles to the aluminum base material and directly form a 1.3 mm or more thick ferromagnetic metal coating layer on the aluminum base material without intervening another intermediate layer between the aluminum base material and the ferromagnetic metal coating layer, the aluminum base material must reach The predetermined temperature may be included in the range of 180 to 300 ℃. Preferably, the predetermined temperature may be included in the range of 200 to 260 °C.

The thermal spray coating method 100 according to various embodiments may further include measuring the temperature of the aluminum base material in order to check whether the aluminum base material is within a predetermined temperature range. By irradiating a laser to the base material and receiving the reflected laser, the temperature of the base material can be measured.

The step 130 is a step of forming a ferromagnetic metal coating layer on one surface of the aluminum base material maintained at a predetermined temperature. At this time, the other surface of the aluminum base material can be heated so that the base material is maintained at a predetermined temperature. Step 130 may include melting the ferromagnetic metal wire and spraying the molten ferromagnetic metal particles on one surface of the base material. Steps 120 and 130 may be performed with the thermal spray coating apparatus 200 as shown in FIG. 2 . In the melting of the ferromagnetic metal wire, electricity may be supplied to the metal wire and the metal wire may be melted by an electric arc generated by the contact of the metal wire. In the step of spraying the molten ferromagnetic metal particles on one surface of the base material, compressed air or inert gas is sprayed from the rear side of the metal particles in the direction of the base material, and the molten metal particles are accelerated by the compressed air or inert gas so that the metal particles are aluminum. It can be sprayed on one side of the base material. A ferromagnetic metal coating layer may be formed on one surface of the aluminum base material by spraying the ferromagnetic metal wire molten metal particles to the aluminum base material and depositing the metal particles on one surface of the aluminum base material reaching a predetermined temperature.

In various embodiments, the ferromagnetic metal coating layer formed on the aluminum base material is made of a ferromagnetic metal wire. In an embodiment, the ferromagnetic metal wire has pure iron (Fe) as a main component, and may contain 97 wt% or more of pure iron (Fe). Table 1 below shows the weight ratio of elements constituting the ferromagnetic metal wire used to form the thermal spray coating layer in an embodiment when the ferromagnetic metal wire is 100 wt%.

element C Si Mn P S Ni Cr Cu Ti Fe Weight ratio (wt%) 0.09 0.91 0.93 0.023 0.014 0.01 0.01 0.15 0.19 97.773

6b is a photograph of forming an iron spray coating layer on an aluminum base material by a spray coating method according to various embodiments.

Referring to FIG. 6b, in various embodiments, by forming a ferromagnetic metal coating layer by arc spray coating while maintaining the aluminum base material at a predetermined temperature within the range of 180 to 300 ° C., the ferromagnetic metal coating layer is applied to the aluminum base material. It may be formed with an average thickness of 1.3 mm to 2.5 mm without lifting.

In one embodiment, by forming a coating layer on one surface of the aluminum base material by arc spraying coating with a metal wire containing 97 wt% or more of pure iron (Fe) in a state where the aluminum base material is maintained at a predetermined temperature within the range of 180 to 300 ° C., The coating layer may contain 97 wt% or more of Fe (pure iron) without lifting with respect to the aluminum base material and be formed with an average thickness of 1.3 mm to 2.5 mm.

In various embodiments, the thermal spray coating method 200 may further include a step 140 of cooling the base material and the metal coating layer. In step 140, cooling air may be sprayed on the base material to cool the base material and the metal coating layer. In one embodiment, the base material and the metal coating layer may be cooled by disposing a block bar having good thermal conductivity on one surface and the other surface of the base material and spraying cooling air on one surface of the block bar. By bringing the block bar into contact with the base material and cooling the base material and the metal coating layer, the coating layer is prevented from being separated from the base material due to the difference in thermal stress due to the difference in the material of the aluminum base material and the ferromagnetic metal coating layer, and the flatness of the coating layer can be maintained.

3 is a side view illustrating a thermal spray coating apparatus according to various embodiments, and FIG. 4 is a cross-sectional view of a thermal spray coating apparatus according to various embodiments.

3 and 4, the thermal spray coating apparatus 200 according to various embodiments is an electric arc thermal spray coating device that melts a metal wire by an electric arc and disperses it with compressed air to form a thermal spray coating layer on the surface of the base material. . The thermal spray coating apparatus 200 according to various embodiments may form a ferromagnetic metal coating layer 222 on the aluminum base material 230 . The apparatus 200 may include a thermal spray gun 210 and a heater 240 . The thermal spray gun 210 may melt the ferromagnetic metal wire 220 and spray the molten ferromagnetic metal particles 221 onto one surface of the aluminum base material. The molten ferromagnetic metal particles 221 sprayed from the thermal spray gun 210 may be deposited on one surface of a base material of aluminum to form a coating layer 222 . The heater 240 is disposed on the other surface of the aluminum base material 230 , and may heat or maintain the base material 230 at a predetermined temperature.

In various embodiments, while the molten ferromagnetic metal particles 221 sprayed from the thermal spray gun 210 are deposited on one surface of the base material of aluminum, the base material 230 is maintained at a predetermined temperature within the range of 180 to 300 ℃ heater 240 may be activated. Alternatively, the heater 240 may be preferably operated so that the base material 230 is maintained at a predetermined temperature within the range of 200 to 260 °C.

In an embodiment, the ferromagnetic metal wire 220 may contain pure iron (Fe) in an amount of 97 wt% or more with pure iron (Fe) as a main component. For example, the ferromagnetic metal wire 220 may be a steel wire shown in Table 1.

In the embodiment shown in FIG. 4 , the thermal spray gun 210 may include a guide unit 211 , a power supply unit 212 , and an injection unit 213 . The guide 211 may guide the ferromagnetic metal wire 220 into the thermal spray gun at a constant speed. The power supply unit 212 may supply electricity to the ferromagnetic metal wire to charge one metal wire as an anode and the other metal wire as a cathode. An electric arc may be generated at the point where the charged metal wires meet, and the ferromagnetic metal wire may be melted by the generated electric arc. The injection unit 213 may accelerate the ferromagnetic metal particles 221 by spraying compressed air 214 to the ferromagnetic metal wire melted by the electric arc generated by the contact of the ferromagnetic metal wire having an electrical polarity. The accelerated ferromagnetic metal particles 221 may be deposited on one surface of the aluminum base material 230 to form a ferromagnetic metal coating layer 222 on the aluminum base material 230 .

In various embodiments, by forming the ferromagnetic metal coating layer 222 by the thermal spray coating apparatus 200 in a state where the aluminum base material is maintained at a predetermined temperature within the range of 180 to 300 ° C., the ferromagnetic metal coating layer 222 is formed of aluminum It may be formed with an average thickness of 1.3 mm to 2.5 mm without lifting with respect to the base material 230 .

In one embodiment, a coating layer on one surface of the aluminum base material by the thermal spray coating apparatus 200 with a metal wire containing 97 wt% or more of pure iron (Fe) while maintaining the aluminum base material at a predetermined temperature within the range of 180 to 300 ° C. By forming, the coating layer 222 can be formed with an average thickness of 1.3 mm to 2.5 mm containing Fe (pure iron) of 97% by weight or more without lifting the aluminum base material.

5 is a top view of a thermal spray coating apparatus according to an embodiment.

Referring to FIG. 5 , the thermal spray coating apparatus according to an embodiment may further include a block bar 251 . The block bar 251 may be disposed in contact with one surface and the other surface of the aluminum base material 230 on which the coating layer is formed and fixed by a vice 254 . An injection pipe 252 for spraying cooling air 253 may be disposed on one side of the block bar 251 . In one embodiment, a block bar 251 having good thermal conductivity is placed in contact with one surface and the other surface of the base material 230 and cooling air is sprayed on one surface of the block bar 251 to the base material 230 and the metal coating layer 222. can be cooled. The block bar 251 is brought into contact with both sides of the base material to cool the base material 230 and the metal coating layer 222, thereby preventing the coating layer from being separated from the base material due to the difference in thermal stress according to the material difference between the aluminum base material and the ferromagnetic metal coating layer. It is possible to maintain the flatness of the coating layer.

Claims (15)

In the thermal spray coating method of forming a ferromagnetic metal coating layer on an aluminum base material,
preparing one surface of the base material on which the coating layer is to be formed;
heating the other surface of the base material to bring the base material to a predetermined temperature; and
A thermal spray coating method comprising the step of forming the ferromagnetic metal coating layer on one surface of the base material maintained at the predetermined temperature.
The method according to claim 1,
The step of forming the ferromagnetic metal coating layer on one surface of the base material maintained at the predetermined temperature may include heating the other surface of the base material to maintain the base material at the predetermined temperature.
The method according to claim 1,
The step of preparing one surface of the base material to form the coating layer,
A thermal spray coating method comprising the steps of cleaning one surface of the base material, and blasting one surface of the base material.
The method according to claim 1,
Further comprising the step of cooling the base material on which the coating layer is formed, a thermal spray coating method.
The method according to claim 1,
Further comprising the step of measuring the temperature of the base material,
The predetermined temperature is included in the range of 180 to 300 ℃, thermal spray coating method.
The method according to claim 1,
The step of forming the ferromagnetic metal coating layer on one surface of the preheated base material,
Melting the ferromagnetic metal wire, and spraying the molten ferromagnetic metal particles on one surface of the base material, a thermal spray coating method.
The method according to claim 1,
The coating layer, containing more than 97% by weight of Fe (pure iron), thermal spray coating method.
8. The method of claim 7,
The coating layer is formed on one surface of the base material with an average thickness of 1.3 mm to 2.5 mm, a thermal spray coating method.
5. The method according to claim 4,
The step of cooling the base material on which the coating layer is formed,
Placing a block bar on one surface and the other surface of the base material, and spraying the cooling air on one surface of the block bar, a thermal spray coating method.
In the thermal spray coating apparatus for forming a ferromagnetic metal coating layer on an aluminum base material,
a thermal spray gun for melting the ferromagnetic metal wire and spraying the molten ferromagnetic metal particles on one surface of the base material; and
A thermal spray coating device disposed on the other surface of the base material and including a heater for heating the base material to a predetermined temperature.
11. The method of claim 10,
Further comprising a block bar disposed in contact with the one surface and the other surface of the base material on which the coating layer is formed, a thermal spray coating device.
11. The method of claim 10,
The predetermined temperature is included in the range of 180 to 300 ℃, thermal spray coating device.
11. The method of claim 10,
The ferromagnetic metal wire, containing 97% by weight of Fe (pure iron), a thermal spray coating device.
11. The method of claim 10,
The warrior gun,
a guide for guiding the ferromagnetic metal wire;
A power supply unit for supplying electricity to the ferromagnetic metal wire, and
Including a spraying unit for spraying compressed air to the ferromagnetic metal wire melted by the electric arc generated by the contact of the ferromagnetic metal wire supplied with electricity, a spray coating device.
In the aluminum base material having a ferromagnetic metal coating layer manufactured by the manufacturing method according to claim 1,
An aluminum base material comprising a thermal spray coating layer formed on one surface of the base material, containing 97 wt% or more of iron, and having an average thickness of 1.3 mm to 2.5 mm.

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