KR20190102514A - Internal cooling channel vapor coating device and method - Google Patents

Abstract

Disclosed are a vapor coating device for a cooling channel and a method thereof which can drastically improve internal cooling quality. According to an aspect of the present invention, the vapor coating device for a cooling channel comprises: a container for coating placed in a heating furnace of a high-temperature environment, and provided with an upper and a lower plate and a processing space divided by a side wall; an upper donor box which is divided in an upper space of the processing space by an upper partition separated from the upper plate, and stores a coating material of a pellet form manufactured by sintering metal powder; a lower donor box which is divided in a lower space of the processing space by a lower partition separated from the lower plate, and stores a coating material of a pellet form manufactured by sintering metal powder; an upper and a lower carrier gas conduit connected to the upper and the lower donor box respectively to introduce carrier gas from the outside to the upper and the lower donor box respectively; and an upper and a lower reaction gas manifold which form an introduction path to introduce gaseous reaction gas for coating generated by the upper and the lower donor box with carrier gas to the cooling channel of an object to be coated, play a role of a jig to fix the object to be coated in the processing space between the upper and the lower donor box, and are symmetric vertically.

Description

Cooling Channel Vapor Coating System and Method {INTERNAL COOLING CHANNEL VAPOR COATING DEVICE AND METHOD}

The present invention relates to a cooling channel vapor phase coating apparatus and method, and more specifically, to prevent oxidation by introducing a reaction gas into a coating object (for example, a turbine blade) in which a passage such as an internal cooling channel is formed. The present invention relates to a cooling channel vapor phase coating apparatus and method of vapor phase coating for forming a coating layer.

Surfaces of components operating in high temperature environments, such as turbine blades or vanes of gas turbine engines, other airfoils, etc., generally form a metal coating layer alone or in various combinations with other materials. This metal coating layer confers the ability to resist oxidation, corrosion and sulfiding conditions that occur during operation in high temperature environments.

Among the various methods of forming a metal coating layer for preventing oxidation or corrosion, one or more protective metals such as aluminum or aluminum alloy are exposed to a high temperature environment to generate a reactive gas in the form of a vapor, and maintain the generated vapor in a high temperature environment. There is a vapor coating method (Vapor coating) to form an aluminide coating layer by introducing into the processing space to be deposited on the surface to be coated.

The vapor phase coating method is carried out in a non-oxidizing or inert atmosphere (e.g. hydrogen, nitrogen, helium or argon) in a coating container or chamber called " retort ", and coating objects such as turbine blades are usually pellets that are housed in porous boxes. Or with an aluminide coating source in the form of a powder at a designated coating location in the coating container.

The coating container is charged in a heating device such as a heating furnace to generate a reaction gas, which is a coating vapor that deposits on the surface of the object to form a protective film (coating layer), and generally generates a reaction gas such as fluoride, chloride, or bromide. The halide (halide) activator is used because it is very reactive and combines with a compound or another element to form a stable substance.

The halide activator is introduced into the coating container in gaseous form and reacts with the aluminide coating source in pellet or powder form to produce an aluminide-containing gas (hereinafter referred to as 'reaction gas'), or in a coating container. The reactive halogen gas of the halide activator of the raw material is reacted with the coating source to generate a reaction gas.

The reaction gas is transferred in the coating container by a non-oxidizing or inert carrier gas such as hydrogen, nitrogen, helium or argon. In a typical gas phase coating system, the carrier gas is introduced at the bottom of the container and the aluminide-containing gas is moved upward to coat the coating object, or vice versa, and the aluminide-containing gas is diffused to coat the coating object.

However, most of the conventional vapor phase coating methods, as mentioned above, because the one-way coating method to implement the coating on the object by introducing the reaction gas from one side (upper or lower side) of the coating container, the cooling channel inside, such as turbine blades or vanes It is difficult to secure uniformity of coating thickness when internal coating of a coating object having a hollow structure in which a passage such as an internal cooling channel is formed.

Moreover, for parts operating in high temperature environments such as turbine blades or vanes, the non-uniformity of the internal coating thickness is a major cause of abnormalities in the turbine coolant flow (TBN Coolant Flow), which is likely to lead to a reduction in the life of the device. . Accordingly, it is urgent to prepare a method for securing uniformity of the inner coating on the hollow part in which a passage such as a cooling channel is formed.

Japanese Patent Laid-Open No. 2001-512181

The technical problem to be solved by the present invention is a gas phase coating method that can significantly improve the internal coating quality for the coating target, the passage (Passage) such as the internal cooling channel (internal cooling channel), such as turbine blades or vanes It is an object of the present invention to provide a cooling channel vapor phase coating apparatus and method.

According to one aspect of the present invention as a means for solving the problem,

An apparatus for treating an oxidation resistant coating on an internal cooling channel formed inside an object to be coated,

A coating container placed inside a furnace of a high temperature environment, the coating container having a treatment space partitioned into a top plate, a bottom plate, and a side wall;

An upper donor box partitioned in an upper space of the processing space through an upper plate spaced apart from the upper plate, and containing a coating material in pellet form made by sintering metal powder;

A lower donor box partitioned in a lower space of the processing space through a lower diaphragm spaced apart from the lower plate, and containing a coating material in pellet form made by sintering metal powder;

An upper carrier gas conduit and a lower carrier gas conduit respectively connected to the upper donor box and the lower donor box to introduce carrier gas from the outside into the upper donor box and the lower donor box, respectively; And

Forming an introduction path for introducing a gaseous coating reaction gas generated in the upper and lower donor boxes together with a carrier gas into the cooling channel of the coating object, and treating the coating object between the upper donor box and the lower donor box; It provides a cooling channel gas phase coating apparatus including a vertical symmetric upper reaction gas manifold and a lower reaction gas manifold serving as a jig for fixing to the space.

The cooling channel gas phase coating apparatus according to an aspect of the present invention may further include a fan installed on the side wall of the container for coating to exhaust the surplus reaction gas remaining after the coating treatment to the outside.

In addition, sealing members may be provided at end portions of the upper reaction gas manifold and the lower reaction gas manifold that face each other, respectively, which contact the upper and lower openings of the coating object.

In addition, the cooling channel gas phase coating apparatus according to an aspect of the present invention, the controller for controlling the supply of the carrier gas to be supplied to each of the upper donor box and the lower donor box through the upper carrier gas conduit and the lower carrier gas conduit; can do.

At this time, the carrier gas of a predetermined pressure is simultaneously supplied to the upper and lower donor boxes under the control of the controller, and the reaction gas generated in the upper and lower donor boxes is coated through the upper and lower reaction gas manifolds by the carrier gas. It can be configured to be introduced into the cooling channel simultaneously at the top and bottom of the object.

Alternatively, the carrier gas of a constant pressure is alternately supplied to the upper and lower donor boxes by the control of the controller, and the reaction gas generated in the upper and lower donor boxes is used to supply the upper and lower reaction gas manifolds by the carrier gas. It may be configured to be introduced into the cooling channel alternately at the top and bottom of the coating object.

According to another aspect of the present invention as a means of solving the problem,

As a method for the oxidation-resistant coating treatment of the internal cooling channel (Internal cooling channel) formed in the interior of the coating object,

a) fixing the object to be coated with the upper reaction gas manifold and the lower reaction gas manifold at a designated position of the coating container located inside the furnace in a high temperature environment;

b) applying heat to the coating container through a heating furnace to generate a coating reaction gas from the coating raw material contained in the upper door box and the lower donor box inside the coating container;

c) supplying carrier gas from the outside to the upper donor box and the lower donor box inside the coating container through an upper carrier gas conduit and a lower carrier gas conduit; And

d) The coating gas is introduced at the upper and lower portions of the coating object through the upper reaction gas manifold and the lower reaction gas manifold using a carrier gas to uniformly distribute the oxidation-resistant coating layer on the wall partitioning the cooling channel. It provides a cooling channel vapor phase coating method comprising the step of forming.

Preferably, the carrier gas of a predetermined pressure is simultaneously supplied to the upper and lower donor boxes in the step c), and the reaction gas generated in the step b) by the carrier gas and the top of the coating object in the step d) It can be introduced into the cooling channel at the same time from the bottom.

As another example, the carrier gas of a predetermined pressure is alternately supplied to the upper and lower donor boxes in step c), and the reaction gas generated in step b) is applied to the upper portion of the coating object in step d) by the carrier gas. It can also be introduced into the cooling channel alternately from and below.

According to the cooling channel vapor phase coating apparatus and method according to an embodiment of the present invention, the oxidation-resistant coating on the inner surface of the hollow structure in which the passage (Passage), such as the internal cooling channel (internal cooling channel) is formed, such as turbine blades or vanes By supplying the reaction gas (coating vapor) simultaneously or alternately in both directions, it is possible to form the oxidation resistant coating layer with a uniform thickness throughout the inner coating target surface.

In addition, by securing uniformity of coating thickness, it is possible to give more resistance to oxidation, corrosion and sulfidation in high temperature environment, which can improve product quality and extend life, and the overall device configuration is considerably simple. Treatment facilities can be built at low cost. That is, it is possible to build a coating treatment facility capable of low-cost, high-quality coating treatment.

1 is a schematic configuration diagram of a cooling channel vapor phase coating apparatus according to the present invention;
FIG. 2 is an enlarged view of the reaction gas manifold of FIG. 1. FIG.
3 illustrates another preferred embodiment of a manifold.
4 is a flow chart schematically illustrating a coating process for a coating object performed through a cooling channel vapor phase coating apparatus according to the present invention.

It will be described in a preferred embodiment of the present invention.

In describing the present invention, terms used in the following description are merely used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In addition, the terms "comprise" or "having" in the present specification are intended to indicate that there exists a feature, number, step, operation, component, part, or a combination thereof described in the specification, and one or more other It is to be understood that the present invention does not exclude the possibility of the presence or the addition of features, numbers, steps, operations, components, parts, or a combination thereof.

In addition, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the terms “… unit”, “… unit”, “… module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. Can be.

In the description with reference to the accompanying drawings, the same components will be denoted by the same reference numerals and duplicate descriptions of the same components will be omitted. In the following description of the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

The present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram of a cooling channel vapor phase coating apparatus according to the present invention, and FIG. 2 is an enlarged view of the reaction gas manifold of FIG. 1.

The coating apparatus 10 according to the present invention uses a product having a passage formed therein as a coating target T. The coating object T may be, for example, a turbine blade having a cooling channel formed therein, but is not limited thereto. That is, any product that has a passage or flow path formed therein and needs an oxidation-resistant coating on the surface partitioning the passage or flow path may be the target.

Hereinafter, a turbine blade having a platform and a shroud at the top and a bottom thereof as an object to be coated and an internal cooling channel as a cooling medium flow passage will be described as an example.

1 to 2, the present invention is a vapor phase coating method of forming a coating layer for preventing oxidation by introducing a reaction gas into the interior space of the coating target (T) in which a passage (Passage) such as an internal cooling channel (Passage) is formed Coating apparatus, comprising a coating container (12), upper and lower donor boxes (14, 15), upper and lower carrier gas conduits (16, 17), and upper and lower reactive gas manifolds (18, 19). .

The coating container 12 may be placed inside a heating device (not shown) such as a heating furnace maintained in a high temperature environment. The coating container 12 may be a tubular structure composed of an upper plate 120, a lower plate 122, and a side wall 124 that define a predetermined processing space 126, and the side wall 124 may have a surplus remaining after coating treatment. A ventilator 13 for external forced exhaust of the reaction gas may be installed.

The main function of the coating container 12 is to produce a reaction gas which is a coating vapor deposited on the inner surface (surface partitioning channel) of the coating object T to form a protective film (coating layer). Metals containing a halide activator, which is a highly reactive compound such as fluoride, chloride, and bromide, are combined with a compound or another element to form a stable substance to generate a reaction gas.

The metal to be the coating raw material (S) may preferably be aluminum or an aluminum alloy mainly composed of aluminum, and may be provided in powder form or pellet form. Metal powder to be the coating material (S) is accommodated in the upper donor box 14 and the lower donor box 15, the vapor form (Vapor) to form a protective film by being exposed to a high temperature environment in the state stored in the donor box The reaction gas of is produced.

 The upper donor box 14 and the lower donor box 15 in which the coating material S is accommodated may be formed at the upper and lower portions of the processing space 126 inside the coating container 12, respectively. More specifically, the upper and lower portions of the processing space 126 by the upper plate 140 and the lower plate spaced apart from the upper plate 120 and the lower plate 122, which respectively partition the coating container 12 by a predetermined distance. The space may be partitioned into a predetermined volume.

The upper carrier gas conduit 16 and the lower carrier gas conduit 17 may be connected to the upper donor box 14 and the lower donor box 15, respectively. The upper and lower carrier gas conduits 16 and 17 are connected to the upper and lower donor boxes 14 and 15, respectively, and serve to introduce the carrier gas supplied from the outside into the upper and lower donor boxes 14 and 15, respectively. The carrier gas introduced into the donor box serves to carry the reaction gas.

Carrier gas is specifically supplied from the outside through the upper and lower carrier gas conduits 16 and 17 at a predetermined pressure to coat the reaction gas generated in each of the upper and lower donor boxes 14 and 15 to be coated (T). It serves to transport to the side, the reaction gas carried by the carrier gas is deposited on the target surface of the coating target (T) to form a protective film that resists oxidation and corrosion.

The carrier gas can be a non-oxidizing or inert gas. More specifically, the valve may be a non-oxidizing or inert gas such as hydrogen, nitrogen, helium or argon gas, which is compressed and stored under high pressure in a separate storage tank provided outside the furnace and operated with a coating start command. Upon opening it can be supplied to the upper and lower donor boxes 14, 15 through the upper and lower carrier gas conduits 16, 17.

The upper reaction gas manifold 18 and the lower reaction gas manifold 19 provide an introduction path for introducing the reaction gas into the coating object space of the coating object T, such as a cooling channel inside the turbine blade. Specifically, it serves to introduce the gaseous coating reaction gas generated in the upper and lower donor boxes 14 and 15 together with the carrier gas into the cooling channel (not shown) of the coating object T.

 The upper reaction gas manifold 18 and the lower reaction gas manifold 19 also fix the coating object T on the processing space 126 between the upper donor box 14 and the lower donor box 15. It also serves as a jig. To this end, the upper reaction gas manifold 18 and the lower reaction gas manifold 19 is a pipe structure in which a straight flow path is formed therein, and at least one pair is provided in a vertically symmetrical structure with respect to the center of the coating target T. Can be.

As shown in an enlarged view of the main portion of FIG. 2 showing an enlarged reaction gas manifold, the sealing members 180 and 190 may be provided at the upper reaction gas manifold 18 and the lower reaction gas manifold 19, respectively. . The sealing members 180 and 190 serve to seal gaps between the openings and the manifolds formed in the upper and lower portions of the coating object T, and the lower and lower reaction gas manifolds of the upper reaction gas manifold 18. 19) may be provided at the top of each.

Sealing members (180, 190) is a material that can be tightly coupled to the opening of the coating object (T) to tightly seal the gap with the manifold, such as silicon or rubber material is preferably, but not limited to, the coating object ( Since the shape of the opening of T) may be modified in various forms, the shape or size thereof is not limited to the hexahedral shape or the specific size illustrated in the drawings.

3 is a view showing another preferred embodiment of the manifold, the upper reaction gas manifold 18 and the lower reaction gas manifold 19 is applied according to the size or volume of the coating target (T) It may be configured to adjust the length. For example, a portion of the tube 18a may be inserted into another neighboring tube 18b having a different diameter, and may be configured to be adjustable in length by adjusting the overlapping section D between the two tubes.

The length adjustment includes a screw-mechanism mechanism that can switch the rotational movement of linear motion when one pipe is rotated with respect to one pipe, and a length adjustment mechanism with a clamp between the two coaxially coupled pipes. Any known type of length adjustment mechanism capable of implementing the adjustment of the length of may be included.

Meanwhile, in FIG. 1 attached above, reference numeral 20 denotes a controller. The controller 20 controls the overall function of the device, including temperature control of the furnace containing the coating container 12. In particular, the carrier gas to be supplied to each of the upper donor box 14 and the lower donor box 15 by controlling the control valves V1 and V2 installed in the upper carrier gas conduit 16 and the lower carrier gas conduit 17 described above. To regulate the supply of

The controller 20 preferably controls the control valves V1 and V2 installed in each gas conduit at the same time so that the carrier gas can be simultaneously supplied from the outside to the upper donor box 14 and the lower donor box 15. have. In this case, since the reaction gas is simultaneously introduced from the upper and lower portions of the coating target T through the upper and lower reaction gas manifolds 18 and 19 through the carrier gas, the time required for the coating process can be greatly shortened.

In some cases, the carrier gas at a constant pressure may be alternately supplied to the upper and lower donor boxes 14 and 15 by the control of the controller 20. In this case, reaction gases generated in the upper and lower donor boxes 14 and 15 are alternately introduced by the carrier gas through the upper and lower reaction gas manifolds 18 and 19 at the upper and lower portions of the coating object T. As a result, an even quality protective film may be formed over the entire surface of the object.

4 is a flowchart schematically illustrating a coating process for a coating target T performed through a cooling channel vapor phase coating apparatus according to the present invention.

Referring to FIG. 4 in conjunction with FIG. 1 above, in the coating through the aforementioned cooling channel vapor phase coating apparatus, first, a coating object T, for example, a turbine blade, is fixed at a designated position of the coating container 12 (S100). . More specifically, the turbine blade T is positioned at a designated position of the coating container 12 located inside the furnace of the high temperature environment by using the upper reaction gas manifold 18 and the lower reaction gas manifold 19. Fix it.

Next, a coating reaction gas is generated from the coating raw material S accommodated in the upper donor box 14 and the lower donor box 15 (S200). Specifically, the coating reaction gas is a coating housed in each of the upper donor box 14 and the lower donor box 15 inside the coating container 12 when heat is applied to the coating container 12 through a heating furnace. It can be produced from the chemical reaction of the raw material (aluminum or aluminum alloy in powder or pellet form).

When the reaction gas is generated, the upper carrier gas conduit 16 and the lower carrier gas conduit 17 are opened so that the carrier gas from the outside is discharged from the upper donor box 14 and the lower donor box inside the container 12 for coating ( 15) to be supplied (S300). At this time, through the controller 20 to properly control the open state of the upper carrier gas conduit 16 and the lower carrier gas conduit 17 so that the coating time and coating thickness can be adjusted.

Finally, the coating reaction gas is applied through the upper reaction gas manifold 18 and the lower reaction gas manifold 19 using the carrier gas supplied through the upper and lower carrier gas conduits 16 and 17. By introducing from the upper and lower portions of the object (T) to be uniformly formed on the inner surface, for example, the wall surface partitioning the cooling channel of the turbine blade (S400).

On the other hand, in the above-described step S300 by controlling the carrier gas of a predetermined pressure to be supplied to the upper and lower donor boxes 14, 15 at the same time or alternately supplied, the reaction gas generated in the step S200 by the carrier gas In the step S400 may be introduced into the cooling channel at the same time or in the upper and lower portions of the coating target (T) or alternately introduced.

According to the cooling channel vapor deposition apparatus and method according to an embodiment of the present invention, the oxidation of the inner surface of the hollow structure in which a passage (Passage), such as an internal cooling channel (internal cooling channel) is formed, such as turbine blades or vanes By coating the reaction gas (coating vapor) at the same time or alternately at the time of coating, it is possible to form an oxidation resistant coating layer with a uniform thickness throughout the inner coating target surface.

In addition, by securing uniformity of coating thickness, it is possible to give more resistance to oxidation, corrosion and sulfidation in high temperature environment, which can improve product quality and extend life, and the overall device configuration is considerably simple. Treatment facilities can be built at low cost. That is, it is possible to build a coating treatment facility capable of low-cost, high-quality coating treatment.

In the detailed description of the present invention, only specific embodiments thereof have been described. It is to be understood, however, that the present invention is not limited to the specific forms referred to in the description, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. Should be.

10: vapor phase coating device 12: coating container
13: ventilator 14: upper donor box
15 lower donor box 16 upper carrier gas conduit
17: lower carrier gas conduit 18: upper reaction gas manifold
19: lower reaction gas manifold 20: controller
120: upper plate 122: lower plate
124: side wall 126: processing space
140: upper plate 150: lower plate
180: sealing member S: coating raw material
T: Coating object (turbine blade) V1, V2: Control valve

Claims (9)

An apparatus for treating an oxidation resistant coating on an internal cooling channel formed in an interior of a coating object T,
A coating container 12 placed inside a furnace in a high temperature environment and having a treatment space 126 partitioned into an upper plate 120, a lower plate 122, and a side wall 124;
An upper donor box 14 partitioned in the upper space of the processing space 126 through the upper plate 140 spaced apart from the upper plate 120 and containing the coating material S in pellet form made by sintering metal powder. );
A lower donor box 15 which is partitioned in a lower space of the processing space 126 through a lower diaphragm spaced apart from the lower plate 122 and accommodates a coating material S in pellet form made by sintering metal powder;
An upper carrier gas conduit 16 connected to the upper donor box 14 and a lower donor box 15 to introduce carrier gas from the outside into the upper donor box 14 and the lower donor box 15, respectively; Lower carrier gas conduit 17; And
An introduction path for introducing a gaseous coating reaction gas generated in the upper and lower donor boxes 15 together with a carrier gas into the cooling channel of the coating object T is formed, and the coating object T is formed on the upper portion. And a top and bottom symmetric upper reaction gas manifold 18 and a lower reaction gas manifold 19 which serve as a jig for fixing to the processing space 126 between the donor box 14 and the lower donor box 15. Cooling channel vapor phase coating device.
The method of claim 1,
Cooling channel vapor phase coating apparatus is installed on the side wall (124) of the coating container (12) is provided with a ventilator (13) for forcibly exhausting the surplus reaction gas remaining after the coating process.
The method of claim 1,
Sealing members 180 and 190 are respectively provided at the end portions of the upper reaction gas manifold 18 and the lower reaction gas manifold 19 which face each other in contact with the upper opening and the lower opening of the coating object T, respectively. Cooling channel vapor phase coating apparatus.
The method of claim 1,
And a controller (20) for controlling the supply of carrier gas to be supplied to each of the upper donor box (14) and the lower donor box (15) through the upper carrier gas conduit (16) and the lower carrier gas conduit (17). Cooling channel vapor phase coating device.
The method of claim 4, wherein
Under the control of the controller 20, the carrier gas of constant pressure is simultaneously supplied to the upper and lower donor boxes 15, and the reaction gas generated in the upper and lower donor boxes 15 is transferred to the upper and lower portions by the carrier gas. Cooling channel vapor phase coating apparatus characterized in that it is introduced into the cooling channel at the same time in the upper and lower portions of the coating object (T) through the reaction gas manifold (19).
The method of claim 4, wherein
By the control of the controller 20, the carrier gas of constant pressure is alternately supplied to the upper and lower donor boxes 15, and the reaction gas generated in the upper and lower donor boxes 15 is transferred to the upper and lower portions by the carrier gas. Cooling channel vapor phase coating apparatus, characterized in that it is introduced into the cooling channel alternately from the top and bottom of the coating target (T) through the lower reaction gas manifold (19).
As a method for the oxidation-resistant coating treatment of the internal cooling channel (Internal cooling channel) formed in the interior of the coating object,
a) fixing the object to be coated with the upper reaction gas manifold and the lower reaction gas manifold at a designated position of the coating container located inside the furnace in a high temperature environment;
b) applying heat to the coating container through a heating furnace to generate a coating reaction gas from the coating raw material contained in the upper door box and the lower donor box inside the coating container;
c) supplying carrier gas from the outside to the upper donor box and the lower donor box inside the coating container through an upper carrier gas conduit and a lower carrier gas conduit; And
d) The coating gas is introduced at the upper and lower portions of the coating object through the upper reaction gas manifold and the lower reaction gas manifold using a carrier gas to uniformly distribute the oxidation-resistant coating layer on the wall partitioning the cooling channel. Forming a cooling channel vapor phase coating method.
The method of claim 7, wherein
Simultaneously supplying carrier gas of a predetermined pressure to the upper and lower donor boxes in step c),
Cooling gas vapor phase coating method characterized in that the reaction gas generated in step b) is introduced into the cooling channel at the same time by the carrier gas at the top and bottom of the coating object in step d).
The method of claim 7, wherein
Alternately supplying a carrier gas of a predetermined pressure to the upper and lower donor boxes in step c),
Cooling gas vapor phase coating method characterized in that the reaction gas generated in the step b) is introduced into the cooling channel by the carrier gas alternately in the upper and lower parts of the coating object in step d).

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