JP2024020014A - Flame spray apparatus and manufacturing method of substrate with coating film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame spray apparatus capable of forming a spray coating film with a high voltage resistance.

SOLUTION: A flame spray apparatus includes: a gas discharge part for discharging gas for transporting powder; a dispersion part that receives a powder raw material and the gas for transporting powder and discharges raw material dispersion gas obtained by dispersing the powder raw material into the gas for transporting powder from a raw material gas discharge part; a flame spray part that receives the raw material dispersion gas from a raw material receiving part and forms a substrate with a coating film by flame spraying using the raw material dispersion gas by a flame spray method or a plasma spray method; and a transportation route that connects the raw material gas discharge part in the dispersion part and the raw material receiving part in the flame spray part and through which the raw material dispersion gas flows. A maximum value X of a cross sectional diameter in the transportation route is larger than a cross sectional diameter Y in the raw material receiving part in the flame spray part, thereby increasing a flow rate of the raw material dispersion gas inside the raw material receiving part and enabling supply of the raw material dispersion gas into a flame jet or a plasma jet injected in the flame spray part.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a thermal spraying apparatus and a method of manufacturing a coated substrate using the same.

Conventionally, a method has been proposed in which dry powder is supplied to a thermal spraying device and thermally sprayed.
For example, Patent Document 1 discloses that a thermal spraying powder, which is a ceramic powder, is supplied in a dry state to a thermal spraying machine using a carrier gas, and the thermal spraying machine sprays the surface of a base material to be thermally sprayed to form a thermal spray coating on the surface of the base material to be thermally sprayed. In the thermal spraying method for forming a film, the thermal spraying powder is a powder mixture obtained by mixing ceramic powder with a specific particle size and ceramic powder with a specific particle size. has been done.

Special table 2018-521218 publication

The present invention relates to a thermal spraying apparatus capable of forming a thermal spray coating with a high withstand voltage, particularly a high withstand voltage per coating thickness (i.e., dielectric breakdown strength) on a substrate, and a coated substrate using the same. Provides a manufacturing method.

The present inventor conducted extensive studies to solve the above problems and completed the present invention.
The present invention includes the following (1) to (6).
(1) A gas discharge section that discharges powder conveying gas;
a dispersion section that receives a powder raw material and the powder conveying gas and discharges a raw material dispersion gas in which the powder raw material is dispersed in the powder conveying gas from a raw material gas discharge section;
a thermal spraying section that receives the raw material dispersion gas from the raw material receiving section and uses the gas to spray by a flame spraying method or a plasma spraying method to form a coated base material;
a conveyance path connecting the raw material gas discharge part in the dispersion section and the raw material receiving part in the thermal spraying part, through which the raw material dispersion gas flows;
has
The maximum value X of the cross-sectional diameter in the conveyance path is larger than the cross-sectional diameter Y in the raw material receiving part of the thermal spraying section, whereby the flow velocity of the raw material dispersion gas inside the raw material receiving part is increased, and the thermal spraying A thermal spraying apparatus capable of supplying the raw material dispersion gas into a flame or a plasma jet that is injected at a part.
(2) The maximum value X of the cross-sectional diameter in the conveyance path is larger than the cross-sectional diameter Z in the raw material gas discharge part of the dispersion section, whereby the flow velocity of the raw material dispersion gas inside the conveyance path is reduced, and the The thermal spraying apparatus according to (1) above, wherein the degree of dispersion of the powder raw material in the raw material dispersion gas is increased.
(3) The maximum value X of the cross-sectional diameter in the conveyance path is 1.25 to 10 times the cross-sectional diameter Y in the raw material receiving part of the thermal spraying part, according to (1) or (2) above. Thermal spray equipment.
(4) According to (2) or (3) above, the maximum value X of the cross-sectional diameter in the conveyance path is 1.25 to 10 times the cross-sectional diameter Z in the raw material gas discharge part of the dispersion part. thermal spray equipment.
(5) The conveyance path is arranged such that the radius of curvature of the curve formed by the central axis of the conveyance path is 120 to 250 mm when the conveyance path is viewed from above in the vertical direction, ) The thermal spraying device according to any one of the above.
(6) A method for producing a coated substrate, the method comprising obtaining a coated substrate by thermal spraying using the thermal spraying apparatus according to any one of (1) to (5) above.

According to the present invention, there is provided a thermal spraying apparatus capable of forming a thermal spray coating with a high withstand voltage, particularly a high withstand voltage per coating thickness (i.e., dielectric breakdown strength) on a base material, and a coating using the same. A method for manufacturing a base material can be provided.

1 is a diagram (schematic diagram) showing a thermal spraying apparatus 1 that corresponds to a preferred embodiment of the thermal spraying apparatus of the present invention. FIG. 2 is a diagram (schematic diagram) mainly showing the portions of the thermal spraying section 10 that are not shown in FIG. 1 . FIG. 2 is a schematic diagram showing a thermal spraying section in the thermal spraying apparatus of the present invention, showing an aspect of thermal spraying by a plasma spraying method. 1 is a cross-sectional photograph (SEM image) of the coated base material [1] obtained in Example 1. It is a cross-sectional photograph (SEM image) of the coated base material [2] obtained in Comparative Example 1.

The present invention will be explained.
The present invention includes a gas discharge section for discharging a powder conveying gas, a gas discharging section that receives a powder raw material and the powder conveying gas, and a raw material dispersion gas in which the powder raw material is dispersed in the powder conveying gas. a dispersion part that discharges the raw material gas from the raw material gas discharge part; a thermal spraying part that receives the raw material dispersion gas from the raw material receiving part and uses it to spray by flame spraying or plasma spraying to form a coated base material; a conveyance path connecting the raw material gas discharge part in the thermal spraying part and the raw material reception part in the thermal spraying part, and through which the raw material dispersion gas flows, the maximum value X of the cross-sectional diameter of the conveyance path is is larger than the cross-sectional diameter Y in the raw material receiving part of the part, thereby increasing the flow velocity of the raw material dispersion gas inside the raw material receiving part, so that the raw material dispersion gas flows into the flame or plasma jet injected in the thermal spraying part. This is a thermal spraying device that can supply dispersion gas.
Such a thermal spraying apparatus will also be referred to below as a "thermal spraying apparatus of the present invention".

Further, the present invention is a method for producing a coated base material, in which a coated base material is obtained by thermal spraying using the thermal spraying apparatus of the present invention.
Such a manufacturing method is also referred to below as the "manufacturing method of the present invention."

The thermal spraying apparatus of the present invention will be explained using FIG. 1.
FIG. 1 is a diagram (schematic diagram) showing a thermal spraying apparatus 1 that corresponds to a preferred embodiment of the thermal spraying apparatus of the present invention. The thermal spraying apparatus of the present invention is not limited to the embodiment shown in FIG.

Thermal spraying apparatus 1 shown in FIG. 1 includes a gas discharge section 3, a dispersion section 4, a thermal spraying section 10, and a conveyance path 7.

<Gas discharge part>
The gas discharge section 3 will be explained.
The gas discharge section 3 discharges a powder conveying gas 31.
The gas discharge section 3 is not particularly limited as long as it can accept gas such as air and discharge the powder conveying gas 31.

As the gas discharge section 3, for example, a conventionally known compressor can be used.
It is preferable that the gas discharge section 3 has a function of dehumidifying the received gas such as air.

The powder conveying gas 31 may be air, for example, and is preferably dry air.

The powder conveying gas 31 discharged from the gas discharge section 3 is introduced into the dispersion section 4 through a flow path such as a pipe.

<Dispersion section>
The dispersion section 4 will be explained.
The dispersion section 4 receives powder raw material 41. It also receives the powder conveying gas 31 discharged from the gas discharge section 3 described above.

The powder raw material 41 preferably contains a fluoride of a rare earth element (Ln).
Here, the fluoride of rare earth element (Ln) is not particularly limited as long as it is a compound consisting of rare earth element (Ln) and fluorine (F). A specific example of the fluoride of rare earth element (Ln) is YF ₃ .

It is preferable that the powder raw material 41 contains 20% by mass or more of rare earth element (Ln) fluoride. This content is more preferably 40% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

In addition to the rare earth element (Ln) fluoride, the powder raw material 41 may also contain a rare earth oxyfluoride (a compound containing Ln, O, and F, such as YOF) or a rare earth oxide (such as Y ₂ O ₃ ). .

The powder raw material 41 preferably contains an alkaline earth metal fluoride.
The alkaline earth metal fluoride is not particularly limited as long as it is a compound consisting of an alkaline earth metal and fluorine (F).

It is preferable that the powder raw material 41 contains ceramic particles as a main component.
Here, "main component" is 70% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 98% by mass or more, still more preferably substantially This means that it is 100% by mass (that is, it does not contain anything other than ceramic particles other than unavoidable impurities that may be mixed in from raw materials or manufacturing processes).
In the following, unless otherwise specified, the term "principal component" will be used in this sense.

Ceramics constituting the ceramic particles include oxide ceramics, nitride ceramics, carbide ceramics, and boride ceramics.

Oxide ceramics include BeO, MgO, CaO, SrO, BaO, ZnO, CdO, Al ₂ O 3 _, Ga ₂ O ₃ , In ₂ O ₃ , Sc ₂ O ₃ , Y ₂ O ₃ , La ₂ O ₃ , SiO ₂ , _GeO2 , _SnO2 , _{TiO2, ZrO2, HfO2, ThO2, V2O3 , Nb2O3 , Ta2O3 , Cr2O3 , MoO3 , WO3 , UO3 , Fe 2O3 , Fe3O4 ,} NiO, _CeO2 , _Ce2O3 , _{Nd2O3 , Sm2O3 , Eu2O3 , Gd2O3 , Dy2O3 , Yb2O3 , Ta 2} O ₅ and Hf ₂ O ₃ are mentioned.

Nitride ceramics include BN, AlN, GaN, InN, ScN, YN, LaN, Si ₃ N ₄ , Ge ₃ N ₄ , Sn ₃ N ₄ , TiN, ZrN, HfN, Th ₃ N ₄ , VN, NbN, TaN. , CrN, Mo ₂ N, WN, Fe ₄ N, CeN, and GdN.

Examples of carbide ceramics include B ₄ C, SiC, TiC, ZrC, HfC, ThC, VC, NbC, TaC, Cr ₃ C ₂ , MoC, WC, UC, Fe ₃ C, and YC.

Examples of boride ceramics include _TiB2 , _ZrB2 , HfB2, _ThB6 , TaB2, _MoB2 , _WB2 , _CrB2 , _NbB2 , _{UB2 ,} NiB, _FeB , and CoB.

The powder raw material 41 preferably has a particle size of 0.01 to 30 μm, more preferably 0.1 to 15 μm, and even more preferably 0.5 to 8 μm.
Here, the particle diameter of the powder raw material 41 is a value determined by measurement using a conventionally known laser diffraction/scattering particle size distribution measuring device.

The powder raw material 41 preferably has an average particle diameter (median diameter) of 0.01 to 30 μm, more preferably 0.5 to 3 μm.
Here, the average particle diameter of the powder raw material 41 is a value obtained by measuring the integrated particle size distribution (volume basis) using a conventionally known laser diffraction/scattering type particle size distribution measuring device.

The dispersing section 4 receives the powder raw material 41 and the powder conveying gas 31, and discharges the raw material dispersion gas 42 in which the powder raw material 41 is dispersed in the powder conveying gas 31 from the raw material gas discharge section 43.
It is preferable that the dispersion section 4 is capable of discharging the raw material dispersion gas 42 from the raw material gas discharge section 43 at a desired constant flow rate.
A conventionally known powder supply device having such a function can be used as the dispersion section 4. An example of such a powder supply device is one manufactured by JEOL Ltd., product number: TP-Z18011VEFDR.

The raw material gas discharge section 43 is a part of a flow path connecting the dispersion section 4 and the thermal spraying section 10 described later, and is directly connected to the dispersion section 4 and extends from the boundary α with the dispersion section 4. shall mean a portion having the same diameter as the path. Therefore, in the case of the thermal spraying apparatus 1 shown in FIG. 1, the flow path from the boundary α with the dispersion section 4 to the boundary β, which is the boundary with the conveyance path 7 described later, has the same diameter. This part corresponds to the raw material gas discharge section 43.
The inner diameter of the flow path in the raw material gas discharge section 43 (the diameter of the cross section in the direction perpendicular to the direction in which the raw material dispersion gas 42 flows) is defined as a "cross-sectional diameter Z."
Here, if there is no part with the same diameter as the diameter of the flow path at the boundary α, for example, the diameter of the flow path gradually increases from the boundary α along the flow direction of the raw material dispersion gas 42, the raw material gas discharge The portion 43 means only the portion of the boundary α. In this case, the cross-sectional diameter of the flow path at the boundary α becomes the "cross-sectional diameter Z."

<Thermal spraying section>
The thermal spraying section 10 will be explained using FIG. 2 in addition to FIG. 1.
FIG. 2 is a diagram (schematic diagram) mainly showing parts of the thermal spraying section 10 that are not shown in FIG.
The thermal spraying section 10 receives the raw material dispersion gas 42 from the raw material receiving section 24, and uses the gas to spray the gas by flame spraying or plasma spraying to form a coated base material.

FIGS. 1 and 2 show a thermal spraying section 10 when thermal spraying is performed by the flame spraying method.
However, in addition to the thermal spraying section 10 shown in FIGS. 1 and 2, there are other embodiments in which thermal spraying is performed by flame spraying, and even such embodiments may fall under the scope of the present invention.

In FIG. 1, the thermal spraying section 10 has a combustion chamber 12 therein, and includes an oxygen passage 14 for supplying oxygen-containing gas to the combustion chamber 12, a main fuel passage 16 for supplying main fuel, and It has a burner 18 for igniting the mixture of oxygen-containing gas and main fuel.
As shown in FIG. 2, the oxygen flow path 14 is connected to an oxygen gas cylinder 51, and oxygen-containing gas is supplied from the oxygen gas cylinder 51 to the oxygen flow path 14. Further, the main fuel flow path 16 is connected to a fuel tank 52, and main fuel is supplied from the fuel tank 52 to the main fuel flow path 16. Here, it is preferable that the thermal spraying section 10 has a control unit 53 in the middle of these flow paths. The control unit 53 controls the pressure and flow rate of the oxygen-containing gas supplied from the oxygen gas cylinder 51 and the pressure and flow rate of the fuel supplied from the fuel tank 52.

A hole (gun nozzle 20) for ejecting a flame 25 is formed in the combustion chamber 12 of the thermal spraying section 10 on the side facing the burner 18, and a cylindrical hole with a hole in the center is formed on the outside of the gun nozzle 20. A tip tube 22 is installed, and a frame 25 can be ejected outward from holes in the gun nozzle 20 and the tip tube 22. By adjusting the size of the hole in the tip tube 22, the speed of the frame 25 can be adjusted.

A raw material receiving section 24 is formed in the tip cylinder 22, and a raw material dispersion gas 42 is supplied into the frame 25 from here.

Here, the raw material receiving section 24 is a part of a flow path connecting the thermal spraying section 10 and the dispersing section 4, and is directly connected to the thermal spraying section 10 and extends from the boundary ε with the thermal spraying section 10. shall mean a portion having the same diameter as the diameter of Therefore, in the case of the thermal spraying apparatus 1 shown in FIG. 1, the flow path from the boundary ε with the thermal spraying section 10 to the boundary δ, which is the boundary with the conveyance path 7, which will be described later, has the same diameter. This part corresponds to the raw material receiving section 24.
The inner diameter of the flow path in the raw material receiving section 24 (the diameter of the cross section in the direction perpendicular to the direction in which the raw material dispersion gas 42 flows) is defined as "cross-sectional diameter Y."
Here, if there is no part with the same diameter as the flow path at the boundary ε, for example, the diameter of the flow path gradually decreases from the boundary δ along the flow direction of the raw material dispersion gas 42, the raw material receiving portion 24 means only the portion of the boundary ε. In this case, the cross-sectional diameter of the flow path at the boundary ε becomes the "cross-sectional diameter Y."

Further, the thermal spraying section 10 of the embodiment shown in FIG. 1 has two raw material receiving sections 24. Furthermore, these raw material receiving parts 24 are formed at positions symmetrical to each other with respect to the central axis of the hole formed at the center of the tip cylinder 22.
It is preferable that the thermal spraying section 10 has an even number of raw material receiving sections 24 as described above, and that they are formed at symmetrical positions with respect to the central axis of the hole formed at the center of the tip tube 22. That is, it is preferable that the raw material receiving portions 24 are formed on the outer circumference of the tip tube 22 at equal intervals in the circumferential direction. In this case, the present inventors have discovered that it is possible to form a sprayed coating on the substrate with a higher withstand voltage, particularly withstand voltage per coating thickness (that is, dielectric breakdown strength).

An auxiliary fuel supply channel 26 is further formed in the tip cylinder 22, and auxiliary fuel can be supplied to the frame 25 from here.
As shown in FIG. 2, the auxiliary fuel supply passage 26 is connected to the auxiliary fuel gas cylinder 54, and auxiliary fuel is supplied from the auxiliary fuel gas cylinder 54 to the auxiliary fuel supply passage 26. Here, it is preferable that the thermal spraying section 10 has a regulator 55 in the middle of this flow path. The regulator 55 controls the flow rate of the auxiliary fuel supplied from the auxiliary fuel gas cylinder 54.

Further, the thermal spraying section 10 of the embodiment shown in FIG. 1 has two auxiliary fuel supply channels 26. Furthermore, these auxiliary fuel supply channels 26 are formed at positions symmetrical to each other with respect to the central axis of the hole formed at the center of the tip tube 22.
It is preferable that the thermal spraying section 10 has an even number of auxiliary fuel supply passages 26 as described above, and that the auxiliary fuel supply passages 26 are formed at symmetrical positions with respect to the central axis of the hole formed at the center of the tip cylinder 22. That is, it is preferable that the auxiliary fuel supply channels 26 are formed at equal intervals on the outer circumference of the tip tube 22. In this case, the present inventors have discovered that it is possible to form a sprayed coating on the substrate with a higher withstand voltage, particularly withstand voltage per coating thickness (that is, dielectric breakdown strength).

A compressed air supply channel 28 is formed in the gun nozzle 20, and compressed air is supplied from the channel so as to flow along the inner side surface of the hole formed in the tip tube 22. This prevents the raw material dispersion gas 42 supplied from the raw material receiving section 24 from adhering to the inner side surface of the hole of the tip tube 22.

Further, the thermal spraying section 10 of the embodiment shown in FIG. 1 has two compressed air supply channels 28. Furthermore, these compressed air supply passages 28 are formed at positions symmetrical to each other with respect to the central axis of the hole formed at the center of the tip cylinder 22.
It is preferable that the thermal spraying section 10 has an even number of compressed air supply passages 28 as described above, and that they are formed at symmetrical positions with respect to the central axis of the hole formed at the center of the tip cylinder 22. That is, it is preferable that the compressed air supply passages 28 are formed at equal intervals on the outer circumference of the tip cylinder 22. In this case, the present inventors have discovered that it is possible to form a sprayed coating on the substrate with a higher withstand voltage, particularly withstand voltage per coating thickness (that is, dielectric breakdown strength).

As shown in FIG. 2, compressed air is supplied to the thermal spraying section 10 at a constant pressure by a compressed air supply device 56.

By thermally spraying the base material 2 using the thermal spraying section 1 of the preferred embodiment illustrated in FIGS. 1 and 2, a coated base material having a thermally sprayed coating can be manufactured.

Here, the oxygen-containing gas supplied from the oxygen channel 14 may be a gas containing oxygen, such as air, or may be a mixture of oxygen and air. Preferably, the oxygen-containing gas is oxygen.

The oxygen-containing gas is preferably supplied at a supply pressure of 10 to 300 psi.

The oxygen-containing gas is preferably supplied at a flow rate of 100 to 1500 L/min, more preferably 200 to 1000 L/min, and even more preferably 350 to 600 L/min.

Further, the main fuel supplied from the main fuel flow path 16 is preferably supplied at a supply pressure of 10 to 300 psi.

The main fuel is preferably supplied at a flow rate of 50 to 600 ml/min, more preferably 100 to 300 ml/min, and even more preferably 140 to 220 ml/min.

Here, as the main fuel, kerosene, acetylene, propylene, propane, ethylene, natural gas, etc. can be used. Among these, the main fuel is preferably kerosene.

In this way, the oxygen-containing gas and the main fuel are supplied to the combustion chamber 12 and mixed, and the resulting mixture is ignited to generate the flame 25. Then, the raw material dispersion gas 42 is supplied into the frame 25 .

The feed rate of the raw material dispersion gas 42 is preferably 20 to 100 ml/min, more preferably 30 to 70 ml/min.
Note that the supply amount here is a value converted to normal temperature and normal pressure.

The solid content concentration contained in the raw material dispersion gas 42 is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, more preferably 15 to 40% by mass, and more preferably 20 to 38% by mass. %, and even more preferably 25 to 35% by mass.

Compressed air does not need to be used, but if it is used, it is preferable to supply the compressed air at a pressure of 0.05 to 1.5 MPa, more preferably at a pressure of 0.3 to 0.8 MPa. Further, the compressed air is preferably supplied at a flow rate of 250 to 2000 L/min, more preferably 400 to 800 L/min.
Note that in some cases, uncompressed gas (for example, the atmosphere) can be used instead of compressed air.

Auxiliary fuel may not be used. It is preferable to use auxiliary fuel because the temperature of the frame 25 can be adjusted.
When the auxiliary fuel is supplied to the frame 25, the temperature of the frame 25 can be lowered by the heat of vaporization when the auxiliary fuel is supplied into the frame 25 and vaporized. In this case, it is preferable because at least a part of the powder raw material can easily form a coating while remaining in an unmolten state.

Acetylene, methane, ethane, butane, propane, propylene can be used as auxiliary fuel.

The auxiliary fuel is preferably supplied at a supply pressure of 0.05 to 1.0 MPa.
Further, the auxiliary fuel is preferably supplied at a flow rate of 5 to 100 L/min, more preferably 10 to 30 L/min.

In the thermal spraying section 10 shown in FIG. 1, the distance from the tip of the tip cylinder 22 to the main surface of the base material 2 is preferably 10 to 250 mm, more preferably 70 to 150 mm.

The base material 2 will be explained.
The base material 2 is not particularly limited, and examples thereof include aluminum _, stainless steel, glass (silica glass, alkali-free glass, etc.), ceramic (sintered body made of _Y2O3 , AlN, _{Al2O3 ,} etc.), carbon, etc. It will be done.

Although the size and shape of the base material 2 are not particularly limited, it is preferably plate-shaped. In the manufacturing method of the present invention, it is preferable to form a film on the main surface of such a plate-shaped base material (also referred to as a substrate).

The thermal spraying part in the thermal spraying apparatus of the present invention may be sprayed by a flame spraying method as described above with reference to FIGS. 1 and 2, but it may be sprayed by a plasma spraying method. Good too.
Hereinafter, the thermal spraying section of the thermal spraying apparatus of the present invention, which performs thermal spraying by the plasma spraying method, will be explained using FIG. 3.
Note that FIG. 3 shows a preferred embodiment, and the thermal spraying section in the thermal spraying apparatus of the present invention is not limited to this.

Further, in the thermal spraying apparatus 1' shown in FIG. 3, the configuration other than the thermal spraying section 60 may be the same as that shown in FIG. 1.

In FIG. 3, the thermal spraying section 60 has a pair of electrodes: a nozzle-shaped anode 61 and a cathode 62 arranged at the center thereof. Plasma can be generated by flowing an inert gas (argon, nitrogen, hydrogen, etc.) from the gas introduction part 63 into the donut-shaped gap between the anode and cathode and ionizing the gas by arc discharge. The plasma gas is ejected from the nozzle-shaped anode 61 to the outside of the thermal spraying section 60 as a plasma jet 65 .

The raw material dispersion gas 42 is supplied to the plasma jet 65 through a pipe-shaped raw material receiving section 66 connected to the vicinity of the outlet of the nozzle-shaped anode 61 . The raw material dispersion gas 42 supplied to the plasma jet is heated in the plasma, becomes molten, and is jetted out from the anode 61 on the plasma jet 65 to form a coating 68 on the surface of the base material 67 .

The raw material receiving section 66 is a part of the flow path connecting the thermal spraying section 60 and the dispersion section 4, and is directly connected to the thermal spraying section 60 and extends from the boundary ε with the thermal spraying section 60. shall mean a portion having the same diameter as the diameter of Therefore, in the case of the thermal spraying apparatus 1' shown in FIG. 3, the flow path from the boundary ε with the thermal spraying section 60 to the boundary δ which is the boundary with the conveyance path 7, which will be described later, has the same diameter. This portion corresponds to the raw material receiving section 66.
The inner diameter of the flow path in the raw material receiving section 66 (the diameter of the cross section perpendicular to the direction in which the raw material dispersion gas 42 flows) is the "cross-sectional diameter Y".
Here, if there is no part with the same diameter as the flow path at the boundary ε, for example, the diameter of the flow path gradually decreases from the boundary δ along the flow direction of the raw material dispersion gas 42, the raw material receiving portion 66 means only the portion of the boundary ε.

The feed rate of the raw material dispersion gas 42 to the plasma jet 65 is preferably 5 to 100 ml/min, more preferably 10 to 50 ml/min.
The solid content concentration contained in the raw material dispersion gas 42 is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, more preferably 15 to 40% by mass, and more preferably 20 to 38% by mass. %, and even more preferably 25 to 35% by mass.

Plasma spraying can be performed by a conventionally known method. Further, it is preferable to perform plasma spraying under treatment conditions that completely melt the powdered raw material contained in the raw material dispersion gas 42 to form a coating made of the powdered raw material on the surface of the base material.

Plasma spraying is preferably carried out at a plasma temperature of 10,000 degrees or higher, more preferably 15,000 degrees or higher. This is because a film having better plasma resistance can be formed.

<Transport path>
The conveyance path 7 will be explained.
The conveyance path 7 is a flow path through which the raw material dispersion gas 42 flows. The conveyance path 7 connects the raw material gas discharge section 43 in the dispersing section 4 and the raw material receiving sections 24 and 66 in the thermal spraying section 10.

The conveyance path 7 may be a hose or a pipe through which the raw material dispersion gas 42 flows.
The conveyance path 7 is preferably made of resin, and more preferably made of conductive resin. Specifically, it is preferably made of a conductive resin based on polyurethane. Moreover, it is preferable that the hose-shaped conveyance path 7 is configured so that the electricity inside moves (conducts) to the outside so as not to accumulate electricity inside the hose-like conveyance path 7.

The conveyance path 7 is preferably made of a material with a volume resistivity of 5.0×10 ³ Ω·cm or less, more preferably 2.0×10 ³ Ω·cm or less.
In this case, the present inventors have discovered that it is possible to form a sprayed coating on the substrate with a higher withstand voltage, particularly withstand voltage per coating thickness (that is, dielectric breakdown strength).

The conveyance path 7 may have a uniform cross-sectional diameter, but may also have a cross-sectional diameter that gradually widens at the ends, or conversely, gradually narrows.

In the thermal spraying apparatus (thermal spraying apparatus 1, 1') of the present invention, the maximum value It is larger than the cross-sectional diameter Y in the raw material receiving parts 24 and 66 of. As a result, the flow velocity of the raw material dispersion gas 42 inside the raw material receiving parts 24 and 66 becomes higher than the flow velocity inside the conveying path 7, and the raw material is dispersed into the flame 25 or plasma jet 65 sprayed in the thermal spraying parts 10 and 66. Gas 42 can be supplied. As a result, the present inventors have discovered that it is possible to form a sprayed coating on a substrate with a higher withstand voltage, particularly withstand voltage per coating thickness (that is, dielectric breakdown strength).

Here, the maximum value X of the cross-sectional diameter in the conveyance path 7 is preferably 1.25 to 10 times the cross-sectional diameter Y in the raw material receiving parts 24 and 66 of the thermal spraying parts 10 and 60, and 1.5 to 6 It is more preferably 1.5 to 5 times, even more preferably 1.5 to 4 times. As a result, the present inventors have discovered that it is possible to form a thermal sprayed coating on a substrate with a higher withstand voltage, particularly a higher withstand voltage per coating thickness (that is, dielectric breakdown strength).

In the thermal spraying apparatus of the present invention, the maximum value X of the cross-sectional diameter (the diameter of the cross-section in the direction perpendicular to the direction in which the raw material dispersion gas 42 flows) in the conveyance path 7 is equal to the cross-sectional diameter Z at the raw material gas discharge part 43 of the dispersion section 4. It is preferable that it is larger than . In this case, the flow velocity of the raw material dispersion gas 42 inside the conveyance path 7 is lower than the flow velocity inside the raw material gas discharge part 43, and the degree of dispersion of the powder raw material 41 in the raw material dispersion gas 42 within the conveyance path 7 is reduced. increases. As a result, the present inventors have discovered that it is possible to form a sprayed coating on a substrate with a higher withstand voltage, particularly withstand voltage per thickness of the coating (ie, dielectric breakdown strength).

The maximum value X of the cross-sectional diameter in the conveyance path 7 is preferably 1.25 to 10 times, and preferably 1.25 to 6 times, the cross-sectional diameter Z in the raw material gas discharge part 43 of the dispersion part 4. More preferably, it is 1.25 to 5 times, and even more preferably 1.25 to 4 times. As a result, the present inventors have discovered that it is possible to form a thermal sprayed coating on a substrate with a higher withstand voltage, particularly a higher withstand voltage per coating thickness (that is, dielectric breakdown strength).

The maximum cross-sectional diameter X of the conveyance path 7 is preferably 0.75 to 10 mm, more preferably 1.25 to 7 mm.

The cross-sectional diameter Y of the raw material receiving sections 24, 66 of the thermal spraying sections 10, 60 is preferably 0.5 to 5 mm, more preferably 1 to 3 mm.

The cross-sectional diameter Z of the raw material gas discharge section 43 of the dispersion section 4 is preferably 0.5 to 6 mm, more preferably 1 to 4 mm.

The conveyance path 7 is arranged so that the radius of curvature R of the curve (ω shown by a dotted line in FIG. 1) formed by the central axis of the conveyance path 7 is 120 to 250 mm when the conveyance path 7 is viewed from above in the vertical direction. It is preferable. Here, the radius of curvature R is more preferably 150 to 230 mm, and even more preferably 160 to 200 mm. In this case, the present inventors have found that it is possible to form a sprayed coating on the substrate with a higher withstand voltage, particularly a higher withstand voltage per coating thickness (that is, dielectric breakdown strength).

When the conveyance path 7 is divided into two or more, the radius of curvature R of the conveyance path 7 from the branching point γ where it divides into two or more to the boundary β between the raw material gas discharge part 43 and the conveyance path 7 must be within the above range. is preferred.

The conveyance path 7 is fixed using fixing fittings, supports, etc. so that the radius of curvature R of the curve ω formed by the central axis of the conveyance path 7 is within the above range when the conveyance path 7 is viewed from above in the vertical direction. It is preferable to do so.

It is thought that the coated base material obtained by the manufacturing method of the present invention can be used as a member of a semiconductor manufacturing device using plasma. This is because the coating of the coated substrate obtained by the production method of the present invention is dense.
Here, the semiconductor manufacturing equipment member refers to a member exposed to a plasma atmosphere in, for example, an ion implantation device, an epitaxial growth device, a CVD device, a vacuum evaporation device, an etching device, a sputtering device, an ashing device, etc. used in semiconductor manufacturing. These components include, for example, a chamber, a bell jar, a susceptor, a clamp ring, a focus ring, a shadow ring, an insulating ring, a dummy wafer, a tube for generating plasma, a dome for generating plasma, a transmission window, an infrared transmission window, and a monitoring Examples include windows, lift pins for supporting semiconductor wafers, shower plates, baffle plates, bellows covers, upper electrodes, lower electrodes, and electrostatic chucks.

Examples of the present invention will be described below. The invention is not limited to the following examples.

<Example 1>
Using the thermal spraying apparatus shown in FIGS. 1 and 2 above, yttrium particles (average particle diameter: 2 μm) are thermally sprayed as a powder raw material by flame spraying onto the main surface of a 5 mm thick aluminum plate to a thickness of about 200 μm. A thermally sprayed coating having a thickness of 100 mL was formed to obtain a coated substrate [1].

Specifically, thermal spraying was performed under the following conditions.
・Powder transport gas: Dry air ・Powder raw material: Yttrium particles (average particle size: 2 μm)
・Maximum cross-sectional diameter X in the conveyance path: 4mm
・Cross-sectional diameter Y at the raw material receiving part of the thermal spraying part: 1mm
・Cross-sectional diameter Z at the raw material gas discharge part of the dispersion part: 1 mm
- Radius of curvature R of the curve ω formed by the central axis of the conveyance path when the conveyance path is viewed from above in the vertical direction: 161 mm

Further, the processing conditions for flame spraying are as follows.
・Main fuel: Kerosene ・Main fuel supply flow rate to the frame: 218mL/min
・Oxygen-containing gas: Oxygen/oxygen-containing gas supply flow rate to the frame: 580L/min
・Compressed air pressure: Approximately 0.5MPa
・Auxiliary fuel: Acetylene ・Supply flow rate of auxiliary fuel to the frame: 25L/min
・Amount of powder raw material supplied to the frame: 95g/min
・Powder transport gas: dry air ・Supply pressure of raw material dispersion gas to the frame: 0.55 MPa
・Distance from the tip of the tip tube to the main surface of the aluminum substrate (spraying distance): 120mm

<Comparative example 1>
An aluminum substrate with a thickness of 5 mm is prepared, and yttrium particles (average particle size: 30 μm) are used as a powder raw material and plasma sprayed (atmospheric pressure plasma spraying (APS)) onto the main surface of this substrate to form a coating of approximately 200 μm. A coated substrate [2] having a thick coating was obtained.
Note that the thermal spraying apparatus used for plasma spraying here is a conventionally known one, and does not correspond to the thermal spraying apparatus of the present invention.

The processing conditions for plasma spraying are as follows.
(1) Main plasma working gas/gas type: Ar
・Flow rate [NLPM]: 100
(2) Double plasma working gas/gas type: H ₂
・Flow rate [NLPM]: 10
(3) Atmosphere control gas/Gas type: Air/Pressure [bar]: 3.0
(4) Powder supply/raw material type: Y ₂ O ₃
・Average particle size: 30μm
・Supply amount [g/min]: 45
(5) Carrier gas/gas type: Ar
・Supply amount [NLPM]: 3.9
(6) Thermal spraying distance/Thermal spraying distance [mm]: 150

Next, the coated substrate [1] obtained in Example 1 and the coated substrate [2] obtained in Comparative Example 1 were subjected to the following tests.

<1. Withstand voltage measurement>
<1-1 Test method>
A test was conducted by applying a commercial frequency AC voltage using a withstand voltage measuring device (manufactured by Kikusui Electronics Co., Ltd., model: TOS8750). Here, the test frequency was 50 Hz. The measurement environment was air, and the test was conducted at a temperature of 23±2° C. and a humidity of 50%.

<1-2 Measurement procedure>
Each of the coated substrate [1] and the coated substrate [2] was placed on a base with the sprayed surface facing upward. Then, each of the coated substrate [1] and the coated substrate [2] was sandwiched in the thickness direction between two electrodes each having a diameter of 6 mm, and a voltage was applied between the electrodes. Here, the voltage was increased from 0 V at a boost rate of 100 V/sec, and the voltage value when the cut-off current exceeded 1 mA was measured, and this was defined as the withstand voltage value. Furthermore, the strength of dielectric breakdown was calculated by dividing this withstand voltage by the film thickness.
Note that the film thickness was measured using an eddy current film thickness meter.
Further, the test was conducted five times for each of the coated substrate [1] and the coated substrate [2].

<1-3 Measurement results>
The withstand voltage values measured as described above and the calculated dielectric breakdown strengths are shown in Table 1 below.

<2. Vickers hardness test>
<2.1 What is Vickers hardness>
Vickers hardness is defined as the surface area S of a depression, which is determined from the diagonal length d (average of two diagonal lengths) of the produced depression when a test force F is applied to the sample using a square pyramidal diamond indenter with a facing angle θ of 136°. It is obtained by dividing the test force F by (F/S).

here,
HV: Vickers hardness K: constant, k=1/gn=1/9.80665≒0.102
F: Test force [N]
S: Surface area of depression [mm ² ]
d: Average value of two diagonal lengths of the depression [mm]
θ: Face angle of diamond indenter (136°)
gn: Standard gravitational acceleration (JIS Z 2204 Vickers hardness test - Test method reference).

<2-2 Measurement procedure>
The sprayed surface was polished so that when a depression was formed on the sprayed surface with a diamond indenter, the diagonal length of the depression could be accurately measured. After that, the coated substrate was fixed with a jig so that the direction in which the diamond indenter was pressed was the normal direction of the sprayed surface.

The test conditions for the Vickers hardness test are shown below.
・Test force: 2.942N (HV0.3)
・Loading time: 4 seconds ・Holding time: 10 seconds ・Unloading time: 4 seconds The test was conducted under the above test conditions, and the diagonal length was measured using a measuring microscope (30x magnification) to calculate the Vickers hardness. The number of samples was measured five times per condition.
Table 2 shows the measurement results of Vickers hardness.

Vickers hardness is a value that measures the hardness of the particles themselves, and tends to basically depend on the density of the powder raw material and the thermal spray coating. The reason why there is a mixture of high values and low values in the measurement results for the coated base material [2] in Table 2 is thought to be due to the presence of pores in the coat. Furthermore, the reason why the measurement results for the coated base material [1] are stable is considered to be because the thermal spray coating is denser than that for the coated base material [2].

<3. Cross-sectional observation>
After polishing the end face of the sprayed coating to expose the cross section of the sprayed coating, the cross section was observed using a scanning electron microscope (Hitachi High-Technologies Corporation, Hitachi tabletop microscope Miniscope TM3000) and a photograph was taken. .
Cross-sectional photographs of the obtained coated base material [1] and coated base material [2] are shown in FIGS. 4 and 5.
From these figures, it can be confirmed that the film is more densely formed on the coated base material [1] than on the coated base material [2].

1, 1' Thermal spraying device 2 Base material 3 Gas discharge part 31 Powder transport gas 4 Dispersion part 41 Powder raw material 42 Raw material dispersion gas 43 Raw material gas discharge part 7 Conveyance path 10 Thermal spray part 12 Combustion chamber 14 Oxygen flow path 16 Main Fuel channel 18 Burner 20 Gun nozzle 22 Tip tube 24 Raw material receiving section 25 Frame 26 Auxiliary fuel supply channel 28 Compressed air supply channel 51 Oxygen gas cylinder 52 Fuel tank 53 Control unit 54 Auxiliary fuel gas cylinder 55 Regulator 56 Compressed air supply device 60 Thermal spraying Part 61 Anode 62 Cathode 63 Gas introduction part 65 Plasma jet 66 Raw material receiving part 67 Base material 68 Coating

Claims (6)

a gas discharge section for discharging gas for powder conveyance;
a dispersion section that receives a powder raw material and the powder conveying gas and discharges a raw material dispersion gas in which the powder raw material is dispersed in the powder conveying gas from a raw material gas discharge section;
a thermal spraying section that receives the raw material dispersion gas from the raw material receiving section and uses the gas to spray by a flame spraying method or a plasma spraying method to form a coated base material;
a conveyance path connecting the raw material gas discharge part in the dispersion section and the raw material receiving part in the thermal spraying part, through which the raw material dispersion gas flows;
has
The maximum value X of the cross-sectional diameter in the conveyance path is larger than the cross-sectional diameter Y in the raw material receiving part of the thermal spraying section, whereby the flow velocity of the raw material dispersion gas inside the raw material receiving part is increased, and the thermal spraying A thermal spraying apparatus capable of supplying the raw material dispersion gas into a flame or a plasma jet that is injected at a part. The maximum value X of the cross-sectional diameter in the conveyance path is larger than the cross-sectional diameter Z in the raw material gas discharge part of the dispersion section, whereby the flow velocity of the raw material dispersion gas inside the conveyance path decreases, and the flow rate of the raw material dispersion gas inside the conveyance path decreases. The thermal spraying device according to claim 1, wherein the degree of dispersion of the powder raw material within the body is increased. The thermal spraying apparatus according to claim 1 or 2, wherein a maximum value X of the cross-sectional diameter in the conveyance path is 1.25 to 10 times as large as a cross-sectional diameter Y in the raw material receiving part of the thermal spraying part. The thermal spraying apparatus according to claim 2, wherein a maximum value X of the cross-sectional diameter in the conveyance path is 1.25 to 10 times as large as a cross-sectional diameter Z in the raw material gas discharge part of the dispersion part. The thermal spraying apparatus according to claim 1 or 2, wherein the conveyance path is arranged so that the radius of curvature of the curve formed by the central axis of the conveyance path is 120 to 250 mm when the conveyance path is viewed from above in the vertical direction. . A method for producing a coated base material, the method comprising spraying using the thermal spraying apparatus according to claim 1 to obtain a coated base material.

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