KR102130346B1 - Coating method of spray surface - Google Patents

Abstract

The disclosed method for coating a sprayed surface according to the present invention comprises: accelerating the sprayed material particles heated in a molten state on the surface of a base material with compressed air or gas to form a sprayed layer; Planarizing the sprayed layer by processing; And forming a coating layer on the flattened thermal spray layer.
According to the present invention, by flattening the surface of the sprayed layer so that the gap between the particles of the sprayed material is reduced, and forming a coating layer thereon, the absorption amount of the coating material penetrating between the sprayed layer gaps is reduced, so that the thickness of the coating layer can be realized thin and uniform coating is achieved. There is a possible effect.

Description

Coating method of spraying surface {COATING METHOD OF SPRAY SURFACE}

The present invention relates to a method for coating a sprayed surface, and more particularly, to a method in which a thin and uniform coating is possible by flattening a sprayed layer formed on a surface of a base material.

In general, thermal spray coating is one of the surface modification technologies that improves performance without damaging or deforming the base material, and melt or semi-melt state by injecting powder or wire spray material into a spray device that generates a high temperature heat source such as flame or plasma. It is a technology to form a coating layer by colliding and stacking on the surface of a base material at high speed after changing to.

In the beginning, thermal spray coating was mainly used only in special fields such as military facilities, aviation and power generation facilities, but the scope of application was limited, but with the development of the general industry in recent years, abrasion resistance, heat resistance, corrosion prevention, insulation, conduction, and development And as the necessity for granting special functionality increases, the range of application is expanding.

Particularly, when spraying, the coating is applied to the sprayed surface depending on the situation. A technique related to a method of forming a post-treatment coating layer on the sprayed coating layer has been proposed in Korean Patent Publication No. 2011-0077366.

Patent Document 1 discloses a surface treatment method and annealing of a surface treatment of an annealing roll forming a post-treatment coating layer by wet heat treatment after wet coating on the thermal spray coating layer in a state in which a thermal spray coating layer is formed on the surface of the annealing roll.

However, Patent Document 1 has a problem in that when the post-treatment coating layer is formed on the thermal spray coating layer, the coating layer material is absorbed into the gap of the thermal spray coating layer and is not coated at the site, so that the coating is not uniformly performed.

Korean Patent Publication No. 2011-0077366 (Publication date: 2011.07.07.)

The present invention has been devised in view of the above points, and the problem of the present invention is that of the coating material penetrating between the spray layer gaps by flattening the surface of the spray layer so as to reduce the gap of the spray material particles and forming a coating layer thereon. It is an object of the present invention to provide a coating method of a sprayed surface capable of uniform coating while reducing the amount of absorption to realize a thin coating layer.

In order to achieve the above object, a method of coating a sprayed surface according to the present invention comprises: accelerating the sprayed material particles heated in a molten state on the surface of a base material with compressed air or gas to form a sprayed layer; Planarizing the sprayed layer by processing; And forming a coating layer on the flattened thermal spray layer.

The step of flattening the sprayed layer may be implemented by sanding or sanding or grinding.

The spraying layer forming step may be implemented by any one of arc spraying, plasma spraying, flame spraying and HVOF spraying.

When performing the forming of the coating layer, the coating layer may include a primer coating layer and a top coating layer.
In addition, the present invention, removing the oxide layer on the surface of the base material and roughening the surface to form a surface roughness layer; Forming a thermal spray layer by accelerating the thermal spray material particles heated in a molten state on the surface of the surface roughness layer with compressed air or gas; Planarizing the sprayed layer by processing; And forming a coating layer on the surface of the flattened sprayed layer. When performing the sprayed layer forming step, air pressure or gas pressure is sprayed more strongly in the early and late stages compared to the mid-term to realize fine particles in the early and late stages of spraying. It is possible, and the step of flattening the sprayed layer may be implemented by either sanding or sanding.
In addition, the present invention, removing the oxide film layer on the surface of the iron plate base material and roughening the surface to form a surface roughness layer; Forming a sprayed layer by accelerating the aluminum sprayed material particles heated in a molten state on the surface of the surface roughness layer with compressed air or gas; Planarizing the sprayed layer by processing such that the gap between the particles of the aluminum sprayed material is reduced; And forming a coating layer on the surface of the flattened sprayed layer. When performing the forming of the sprayed layer, air or gas pressure is strongly supplied in the early and late stages compared to the middle period to spray the spray material particles in the early and late stages of spraying. While making the particles finer than the material particles, the gap due to the sprayed material particles in the initial and late spraying stages is smaller than the gap caused by the sprayed material particles in the middle of spraying, and the step of flattening the sprayed layer can be implemented by either sanding or sanding.

According to the present invention, by flattening the surface of the sprayed layer so that the gap between the particles of the sprayed material is reduced, and forming a coating layer thereon, the absorption amount of the coating material penetrating between the sprayed layer gaps is reduced, so that the thickness of the coating layer can be realized thin and uniform coating is achieved. There is a possible effect.

1 is a block diagram showing a method of coating a spray surface according to the present invention.
2 is a process chart showing a coating method of the thermal spraying surface according to the present invention.
3 is an enlarged view of A in FIG. 2.
FIG. 4 is an image showing a case where a spraying layer flattening step is not performed when implementing the coating method of the sprayed surface according to the present invention, and the surface roughness inspection and coating finished product according to the case performed.

The above objects, features and other advantages of the present invention will become more apparent by describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings. Hereinafter, a method of coating a sprayed surface according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a method of coating a spray surface according to the present invention, FIG. 2 is a process diagram showing a method of coating a spray surface according to the present invention, and FIG. 3 is an enlarged view of FIG. 2A, This is an image showing the case where the spraying layer flattening step is not performed when implementing the coating method of the sprayed surface by, and the surface roughness inspection of the coated surface according to the performed case and the finished product.

1 to 3, the coating method of the sprayed surface according to the present invention includes a sprayed layer forming step (S10), a sprayed layer flattening step (S20) and a coating step (S30).

On the other hand, before performing the sprayed layer forming step (S10), a surface cleaning step and a surface roughness layer forming step are preceded.

The surface cleaning step is a step of cleaning the surface of the iron plate base material 100 to remove oil and foreign substances remaining on the surface.

That is, in the surface cleaning step, when contaminants, such as oil, remain on the surface of the iron plate base material 100, it affects the thermal spray layer 120, which is a post process, and the adhesion between the iron plate base material 100 and the spray layer 120. It is performed to prevent the peeling phenomenon of the thermal spray layer 120 due to degradation.

The surface roughness layer forming step is a pretreatment sanding step for removing the oxide layer and forming the surface roughness layer 110 by blasting the surface of the iron plate base material 100 with alumina oxide.

In general, the surface of the iron plate is covered with an oxide layer in the manufacturing process. This is to make the rust less likely, the surface roughness layer 110 is formed by removing the oxide film layer and roughening the surface by alumina oxide in the surface roughness layer forming step.

That is, when performing the surface roughness layer forming step, alumina oxide particles having a small size are sprayed onto the surface of the iron plate base material 100 using a blasting machine (not shown in the drawings). The surface roughness layer 110 formed by the surface roughness layer forming step is intended to improve adhesion and bonding strength between the iron plate base material 100 and the thermal spray layer 120.

The spraying layer forming step (S10) is a step of forming the sprayed layer 120 by accelerating particles of sprayed material, such as aluminum, heated to the surface of the iron plate base material 100 in a molten state with compressed air or gas.

At this time, the sprayed layer forming step (S10) may form the sprayed layer 120 by any one method selected from arc spraying, plasma spraying, flame spraying and HVOF spraying.

In the Arc Spray, two aluminum wires charged by the positive and negative electrodes by DC electricity are melted by an arc energy of about 4100°C. It is a method of forming a coating film by colliding with the iron plate base material 100 by compressed air of about 150 m/sec.

Plasma Spray ionizes the mixed inert gas such as argon, hydrogen, nitrogen or helium in the chamber of the nozzle and electrode of low voltage and high electric current through the cable charged with DC+ and DC-. , Forming a plasma energy composed of neutrons, protons, and transferring the aluminum sprayed material in powder form in an appropriate amount and uniform speed in a flame of 16,500° C. to collide with the iron base material 100 by high temperature heat energy and high speed energy. This is a method of forming a coating film.

Flame spray is a spraying method that increases the injection speed to the flame spray and forms a film by using a strong injection shock. It uses fuel gas such as flame, and combustion occurs inside the tube, and the generated combustion gas flows through the nozzle at high speed. It is a method of forming a coating film by spraying raw material powder with high-speed injection gas while spraying, heating and melting at high speed.

HVOF spraying (High Velocity Oxy-Fuel Spray) is called high-speed spraying and transfers powdered aluminum sprayed material into the flame in the flame generated by burning oxygen and fuel (propane, propylene, hydrogen, kerosene, etc.) in the chamber. It is a method of moving through and melting by heat energy of about 3000° C., and then spraying it on the iron plate base material 100 at a high speed of 700 m/sec to form a coating film.

On the other hand, when performing the spraying layer forming step (S10), by changing the air pressure or gas pressure, more fine particles can be formed. For example, when performing the sprayed layer forming step (S10), the air pressure or the gas pressure may be sprayed more strongly in the early and late stages to further fine-tune the particles in the early and late stages of the injection.

The spraying layer flattening step (S20) refers to a post-treatment sanding step of flattening the surface of the sprayed layer 120 by processing.

At this time, the thermal spray layer planarization step (S20) may be implemented by any one method, such as sandpaper processing or sanding processing or grinding processing.

In this way, when the spraying layer flattening step (S20) is performed, the gap between the sprayed material particles in the sprayed layer 120 is reduced, so that when the coating layer 130 is formed on the flattened sprayed layer 120, the sprayed layer 120 gaps are formed. By reducing the amount of absorption of the coating material penetrating therebetween, the thickness of the coating layer can be realized thinly, and uniform coating is possible.

The coating step (S30) is a step of forming the coating layer 130 on the flattened thermal spray layer 120, the coating layer 130 in this embodiment is illustrated as a Teflon coating layer.

Here, since the Teflon coating is thick, a crack is formed in the coating layer, and accordingly, the thickness of the coating layer 130 may be thinned according to the flattening of the thermal spray layer 120, thereby preventing cracking.

That is, in the coating layer forming step (S30), when a coating material such as Teflon coating is applied to the surface of the sprayed layer 120, since the sprayed layer 120 has many pores formed, the coating material penetrates into the pores and is coated. There is no peeling phenomenon and the life of the coating is also increased. However, if the coating material is coated only by sanding the normal base material, the adhesive strength of the coating appears differently depending on the degree of sanding and the service life is shortened.

Moreover, when performing the coating layer forming step (S30), the coating layer 130 includes a primer coating layer and a top coating layer. Primer coating layer, such as a primer (Primer) coating layer is applied thereto, and improves the wear resistance optical. As the top coat layer, a fluororesin coat layer or the like is applied thereto, and gives a gloss to the surface.

On the other hand, when the thermal spray layer 120 is formed using aluminum or the like, when the corrosion due to moisture or salt occurs, the thermal spray layer is first oxidized to form an oxide layer, and the oxide layer prevents the corrosion layer of the iron plate from rising to the surface, and the rigidity It is excellent and can be manufactured in various shapes while making the thickness thin.

Therefore, when performing a surface cleaning step, a surface roughness layer forming step, a spraying layer forming step, and a coating step when coating on a sprayed surface as shown in FIG. 4(a), the surface after coating is also roughly formed because the sprayed surface is rough, It can be seen that the coating chemical is excessively absorbed into the thermal spray layer, causing a lot of chemical consumption, and a problem that the surface of the coating layer is not polished.

On the other hand, when performing the coating method of the sprayed surface according to the present invention as shown in Figure 4 (b), by performing the sprayed layer flattening step (S20) between the sprayed layer forming step and the coating step in the previous step additionally Since the slope is processed with a soft sanding yarn, the coated surface is formed smoothly, and by polishing the uneven surface of the sprayed surface, coating chemicals can be prevented from being absorbed excessively, reducing the consumption of chemicals, and the surface of the coating is dense. , It can be seen that the coating layer is glossy.

The surface roughness of the sprayed surface without performing the sprayed layer planarization step as shown in FIG. 4(a) is 53(μ), while the surface roughness of the sprayed surface after performing the sprayed layer planarization step as shown in FIG. 4(b) is Since it is 38(μ), it can be seen that there is a clear difference.

In conclusion, when the thermal spray layer 120 is formed using aluminum or the like on the surface of the base plate 100, various effects such as atmospheric corrosion, chemical corrosion, high temperature corrosion, thermal conductivity, and ceramic bond coating can be obtained as follows. have.

Ⅰ) Atmospheric corrosion-Aluminum coating is used to suppress heterogeneous metal contact corrosion, and forms an oxide film that serves as a protective coating. Therefore, aluminum coating is the recommended method under various environmental conditions, and is particularly suitable for underwater environments.

Ii) Chemical corrosion-It is effective to protect chemical treatment equipment, refinery equipment, and commercial equipment that are in contact with sea water or exposed to similar environments. When exposed to an acidic environment, when in contact with soft water and hard water, aluminum can be applied to an optimal arc spray wire.

Ⅲ) High temperature corrosion-Coating increases the life of the heat treatment equipment and automobile exhaust system made of iron and prevents thermal shock.

Iv) Thermal conductivity-Cooking utensils used in commercial and home kitchens undergo thermal spray treatment to facilitate heat flow and distribution. In addition, due to the weight characteristics and thermal conductivity of the aluminum coating itself, when the brake disc is coated with aluminum, the disc does not wear and the heat flow is smooth, which is good for cooling the disc when there is a large amount of work.

Ⅴ) Ceramic bond coating-Arc sprayed aluminum is an optimal bond coating that can be used for ceramic materials such as zinc oxide and carbide. The bond's high temperature and fast speed allow for tight bonding on clean surfaces. Because of the tight bond bonding, aluminum can also be used for varistors and thermistors.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may be implemented in other specific forms without changing the technical spirit or essential features of the present invention. You will understand. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

100: iron plate base material
110: surface roughness layer
120: warrior layer
130: coating layer

Claims (4)

Removing the oxide coating layer on the surface of the iron plate base material and roughening the surface to form a surface roughness layer;
Forming a sprayed layer by accelerating the aluminum sprayed material particles heated in a molten state on the surface of the surface roughness layer with compressed air or gas;
Planarizing the sprayed layer by processing such that the gap between the particles of the aluminum sprayed material is reduced; And
And forming a coating layer on the flattened thermal spray layer,
When performing the spraying layer forming step, the air pressure or gas pressure is strongly supplied in the early and late stages compared to the middle period to make the sprayed material particles finer than the sprayed material particles in the middle and later stages of spraying. Make it smaller than the gap due to the particles of thermal spray material in the middle of the injection,
The step of flattening the spray layer is a method of coating a spray surface, characterized in that implemented by either sanding or sanding.
delete According to claim 1,
The step of forming the spray layer is a method of coating a spray surface, characterized in that implemented by any one of arc spraying, plasma spraying, flame spraying and HVOF spraying.
According to claim 1,
When the coating layer forming step is performed, the coating layer includes a primer coating layer and a top coating layer.

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