WO2015147127A1 - Plasma spraying device - Google Patents

Abstract

Provided is a plasma spraying device comprising a primary torch that is provided with a primary positive electrode that has a material intake tube through which a material supply gas containing a spray material is admitted along a central axis and that introduces a primary plasma gas along the central axis, and a secondary torch provided with a secondary negative electrode a central axis of which intersects the central axis of the primary positive electrode. A plasma flame is formed along the central axis of the primary positive electrode by a plasma arc formed between the primary positive electrode and the secondary negative electrode, by the primary plasma gas introduced along the central axis of the primary positive electrode, and by the secondary plasma gas introduced along the central axis of the secondary negative electrode towards the central axis of the primary positive electrode. The material supply gas is admitted from the material intake tube into the plasma flame, the spray material is melted and blown onto a substrate, and a film of the spray material is thereby formed. The plasma spraying device is provided with a supply quantity control unit for controlling the quantity of the material supply gas supplied.

Description

Plasma spraying equipment

The present invention has a main torch having a main anode and a sub torch having a sub-cathode, and forms a film by spraying a sprayed material melted by a plasma arc formed between the main anode and the sub-cathode onto a substrate. The present invention relates to a plasma spraying apparatus.

Conventionally, in a plasma spraying apparatus having a main torch with a main anode and a sub-torch with a sub-cathode, a material discharge hole is provided at the center of the center axis of the main anode of the main torch, and the material discharge hole extends from the center axis of the main electrode. There is known a plasma spraying apparatus that can supply a spraying material along the surface, efficiently melt the spraying material and spray it onto a base material, and form a dense spraying material film with few pores (for example, Patent Documents) 1 and 2).

Japanese Patent No. 3733461 JP 2010-110669 A

In the plasma spraying apparatus as described above, by using the electrode of the main torch as the anode, the cathode that forms the starting point of the plasma arc that becomes a high temperature is on the sub-torch side, so that the adhesion of the sprayed material to the main electrode side can be suppressed. Therefore, it is possible to provide a material discharge hole in the main electrode. That is, in the past, in order to avoid adhesion of the thermal spray material to the main electrode, the thermal spray material was supplied from a direction inclined with respect to the central axis of the main electrode where the plasma arc is formed. A thermal spray material can be supplied along. As a result, the thermal spray material can be easily supplied to the center of the plasma flame, and the thermal spray material can be more reliably brought to the high temperature portion of the plasma flame and can be prevented from being scattered to the periphery. That is, the thermal spray material can be stably supplied to the high temperature part of the plasma flame. And the inventor thought that the characteristic of a film | membrane could be controlled by using as a parameter the supply conditions of the thermal spray material which could not be handled as a parameter so far by being able to supply a thermal spray material stably to the high temperature part of a plasma flame.
Therefore, an object of the present invention is to provide a plasma spraying apparatus capable of forming a film by changing the supply conditions of the spraying material.

In order to achieve the above object, a plasma spraying apparatus of the present invention includes a main anode having a material feeding pipe for feeding a sprayed material along a central axis together with a material supply gas for feeding the sprayed material. A main torch for introducing a main plasma gas along the central axis, and a sub torch including a sub cathode whose central axis intersects the central axis of the main anode, the main anode and the sub cathode A plasma arc formed between the main anode, the main plasma gas introduced along the central axis of the main anode, and the central axis of the main anode along the central axis of the sub-cathode. The sprayed material is fed together with the material supply gas from the material feeding pipe into the plasma flame formed along the central axis of the main anode by the introduced subplasma gas. Is melted In plasma spraying apparatus for forming a coating of the spray material is sprayed on a plasma spraying apparatus, characterized in that it comprises a supply amount controller for controlling the supply amount of the material supply gas.

According to such a plasma spraying device, since the spraying material is sprayed along the central axis of the main anode, the supply amount control unit for controlling the supply amount of the material supply gas for forming the coating on the base material is provided. By controlling the supply amount of the material supply gas, it is possible to form the coating by varying the supply amount of the material supply gas as the spraying material supply condition when reaching the substrate.

In this plasma spraying apparatus, it is preferable that the supply amount control unit controls the supply amount of the material supply gas so as to change the characteristics of the coating to be formed.
According to such a plasma spraying apparatus, it is possible to form coatings having different characteristics by controlling the supply amount of the material supply gas by the supply amount control unit.
In this plasma spraying apparatus, it is preferable that the supply amount control unit controls the supply amount of the material supply gas independently of the supply amount of the thermal spray material.

The characteristic of the film is preferably the thickness of the film to be formed.
According to such a plasma spraying apparatus, it is possible to form coatings having different thicknesses by controlling the supply amount of the material supply gas by the supply amount control unit.

In such a plasma spraying apparatus, it is desirable that the supply amount of the material supply gas is reduced by the control of the supply amount control unit as the thickness of the coating is increased.
According to such a plasma spraying apparatus, it is possible to form a thicker film by reducing the supply amount of the material supply gas by the supply amount control unit, and by increasing the supply amount of the material supply gas. It is possible to form a thinner film.

In such a plasma spraying apparatus, the characteristic of the film may be the hardness of the film to be formed.
According to such a plasma spraying apparatus, it is possible to form coatings having different hardnesses by controlling the supply amount of the material supply gas by the supply amount control unit.

In such a plasma spraying apparatus, it is desirable that the supply amount of the material supply gas is reduced by the control of the supply amount control unit as the hardness of the coating is increased.
According to such a plasma spraying apparatus, it is possible to form a coating with higher hardness by reducing the supply amount of the material supply gas by the supply amount control unit, and increase the supply amount of the material supply gas. Thus, it is possible to form a film having a lower hardness.

In this plasma spraying apparatus, a characteristic database in which the characteristic of the coating and the supply amount of the material supply gas are associated with each other is generated, and the supply amount control unit includes the characteristic and the characteristic of the coating to be formed. It is desirable to control the supply amount of the material supply gas based on a database.
According to such a plasma spraying apparatus, the supply amount control unit controls the supply amount of the material supply gas based on the characteristics of the film to be formed and the characteristic database generated in advance. Easy.

In this plasma spraying apparatus, the supply amount control unit observes at least one of a particle velocity and a particle temperature of the sprayed material sprayed on the base material, and observes the observation result and the coating of the coating to be formed. It is desirable to control the supply amount of the material supply gas based on the characteristics.
According to such a plasma spraying apparatus, since the supply amount of the material supply gas is controlled based on the observation result obtained by observing at least one of the particle velocity and the particle temperature of the sprayed material sprayed on the base material, it is more accurate. Therefore, it is possible to form a film having desired characteristics.

According to the present invention, it is possible to provide a plasma spraying apparatus capable of forming a coating by changing the supply conditions of the spraying material.

It is a figure which shows schematic structure of the composite torch type | mold plasma spraying apparatus 100 demonstrated as one Embodiment of this invention. FIG. 2 is a cross-sectional view taken along the line AA in FIG. It is a figure which shows schematic structure of the twin cathode type | mold plasma spraying apparatus 101 demonstrated as other one Embodiment of this invention. It is an image which shows an example of the particle velocity measured by changing the supply amount Qf of the material supply gas 20. It is a graph which shows the result of having measured the particle velocity of the thermal spray material 20a when the supply amount Qf of the material supply gas 20 is changed. It is sectional drawing which shows the membrane | film | coat 24 formed by making the supply amount Qf of the material supply gas 20 into 1.0 l / min and 10.0 l / min. It is a graph which shows the relationship between the supply amount Qf of the material supply gas 20, and the hardness of the membrane | film | coat 24 formed. It is a figure which shows schematic structure of the integrated plasma spraying apparatus.

Hereinafter, preferred embodiments of the plasma spraying apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

First, a composite torch type plasma spraying apparatus including a main torch and a sub torch will be described as the plasma spraying apparatus of the present invention. The composite torch type plasma spraying apparatus including the main torch and the sub torch according to the present embodiment includes the main torch including the main anode (anode) and the sub torch including the sub cathode (cathode). It is. FIG. 1 shows a schematic configuration of a composite torch type plasma spraying apparatus 100 described as an embodiment of the present invention.

The main torch 1 includes a main anode 3, a main mantle 4 surrounding the main anode 3, an insulator 27 that insulates the main anode 3 and the main mantle 4, and the like, and is concentrically formed by the main mantle 4 and the insulator 27. Is retained.
The main anode 3 is formed of a material having excellent electrical conductivity, for example, a metal such as copper. The main anode 3 includes a material feed pipe 19 having a thermal spray material discharge hole 19a at the center of the tip of the central axis C1. An automatic material supply device 30 for supplying a material supply gas 20 including a thermal spray material 20a is connected to the material supply pipe 19, and the automatic material supply device 30 can be controlled by a control device 31 as a supply amount control unit. It is.

The main mantle 4 includes an opening (nozzle portion) 4a at the tip, and a tapered portion 4b provided between the opening 4a and the insulator 27.

The insulator 27 has a main plasma gas inlet 5 through which the main plasma gas 6 is introduced, and a swirl flow forming portion 50 for the introduced main plasma gas 6. As shown in FIG. 2, the main plasma gas 6 is introduced into the gas annular chamber 51, passes through the four swirl flow forming holes 52, and passes through the inner wall 53 (between the inner wall 53 and the main anode 3) of the insulator 27. It flows toward the opening 4a of the main mantle 4 so as to turn in the space. The swirl flow forming holes 52 may be arranged in a single number or in a plurality, and in the case where a plurality of the swirl flow holes 52 are arranged, the swirl flow forming holes 52 should be evenly arranged around the central axis C1. Is preferred.

As shown in FIG. 1, the positive terminal of the main power supply 7 is connected to the main anode 3, and the negative terminal of the main power supply 7 is connected to the main mantle 4 via the switch 8.

The sub torch 2 includes a sub cathode (sub torch starting electrode) 10, a sub jacket 11 surrounding the sub cathode 10, an insulator 28 that insulates the sub cathode 10 and the sub jacket 11, and the like. The axis C2, that is, the central axis C2 of the sub-cathode 10, is arranged so as to intersect the central axis C1 of the main torch 1, that is, the central axis C1 of the main anode 3, and at a substantially right angle in front of the main anode 3 and the sub-cathode 10. Has been.
The sub-cathode 10 is made of a material having a high melting point, such as tungsten. The sub cathode 10 is held concentrically by the sub jacket 11 and the insulator 28.

The auxiliary mantle 11 has a hole 11a at the tip. The insulator 28 has a sub-plasma gas inlet 12 for introducing the sub-plasma gas 13 and a swirl flow forming portion 50 similar to the insulator 27 of the main torch 1.

The positive terminal of the sub power supply 14 is connected to the sub jacket 11, the negative terminal of the sub power supply 14 is connected to the sub cathode 10 through the switch 15, and is connected to the negative terminal of the main power supply 7 through the switch 9. Is done.

Next, a method for plasma spraying the thermal spray material 20a using the composite torch type plasma spraying apparatus 100 will be described. Here, the thermal spray material 20a indicates, for example, a conductive material such as metal, an insulating material such as ceramics, and the like.
An inert gas that can be turned into plasma, such as argon or helium, is introduced into the main torch 1 from the main plasma gas inlet 5 as a main plasma gas 6 to form a swirling flow of the main plasma gas 6. Further, a high frequency voltage is applied between the main anode 3 and the main mantle 4 by the main power source 7 with the switch 9 opened and the switch 8 closed. As a result, a main plasma arc 16 is formed from the tip of the main anode 3 toward the opening 4 a of the main mantle 4, whereby the main plasma gas 6 is heated and becomes plasma from the opening 4 a of the main mantle 4. Released.

In addition, an inert gas that can be turned into plasma, such as argon or helium, is introduced as a secondary plasma gas 13 from the secondary plasma gas inlet 12 into the secondary torch 2 to form a swirling flow of the secondary plasma gas 13. Further, a high frequency voltage is applied between the sub cathode 10 and the sub jacket 11 by the sub power source 14 with the switch 15 closed. As a result, a sub-plasma arc 17 is formed from the tip 10a of the sub-cathode 10 toward the hole 11a of the sub-jacket 11, whereby the sub-plasma gas 13 is heated and becomes plasma to be emitted from the hole 11a of the sub-clutch 11. Is done.

The central axis C1 of the main anode 3 and the central axis C2 of the sub-cathode 10 intersect outside the main torch 1 and the sub-torch 2 in front of the main anode 3 and the sub-cathode 10, so the switch 9 is closed, When 15 is opened, a conductive path is formed by the hairpin-shaped plasma 18 from the tip 10 a of the sub-cathode 10 to the anode point of the main anode 3.

In this case, the structure of the main torch 1 and the main plasma gas 6 introduced, and the structure of the sub-torch 2 and the amount of the sub-plasma gas 13 introduced into the sub-torch 2 are appropriately set as shown in FIG. As described above, the plasma flame 23 can be formed substantially coaxially with the main torch 1.

The material spray pipe 19 is controlled by a control device 31 together with a material supply gas 20 for supplying a thermal spray material 20a, which is an inert gas that can be turned into plasma, such as argon or helium. The automatic material supply device 30 is fed in. The thermal spray material 20 a discharged together with the material supply gas 20 from the material feed pipe 19 through the opening 4 a of the main mantle 4 is formed on the central axis C 1 of the main anode 3 by the main anode 3 and the sub-cathode 10. The plasma 18 is supplied to the axial center and is melted by the plasma flame 23. In addition, it is preferable that the automatic material supply apparatus 30 can control the supply amount of the material supply gas 20 independently of the supply amount of the thermal spray material 20a.

The melt 21 in which the thermal spray material 20 a is melted proceeds toward the base material 25 together with the plasma flame 23. At this time, the gas is selectively ejected from the plasma trimming portion 22 provided on the connection pipe 26 to the part of the plasma flame containing the melt immediately before the base material 25, so that an inappropriate state is obtained. The plasma flame may be changed to an appropriate shape simultaneously with the removal of the melt. As a result, a melt suitable for film formation can be deposited on the base material 25 at a more appropriate temperature, and the coating 24 of the dense thermal spray material 20a with fewer pores can be efficiently formed.

In the above embodiment, the plasma spraying apparatus 100 provided with one main torch 1 and one sub torch 2 has been described as an example. However, the plasma spraying apparatus including one main torch and a plurality of sub torches is described. It does not matter. For example, a plasma spraying apparatus 101 including a main torch and two sub torches as shown in FIG. 3 may be used. FIG. 3 is a diagram showing a schematic configuration of a twin cathode type plasma spraying apparatus 101 as another embodiment of the present invention.
The plasma spraying apparatus 101 is a twin cathode type plasma spraying apparatus 101 in which an electrode in a main torch is a main anode (anode) and an electrode in a sub torch is a sub cathode (cathode).

The configuration of the main torch 1 and the sub-torch 2 provided in the twin cathode type plasma spraying apparatus 101 is the same as that of the main torch 1 and the sub-torch 2 in the composite torch type plasma spraying apparatus 100, and thus the description thereof is omitted here.
The positive terminal of the main power supply 7 is connected to the sub jacket 11 via the main anode 3, the switch 55 and the switch 45, and the negative terminal of the main power supply 7 is connected to the main jacket 4 via the switch 8. Further, the positive terminal of the sub torch 2 from the sub power source 42 is connected to the sub jacket 11 through the switch 45, and the negative terminal of the sub torch 2 from the sub power source 42 is connected to the sub cathode 10 through the switch 46. In addition, it is connected to the negative terminal of the main power supply 7 through the switch 9.

In the present embodiment, another sub-torch 39 is disposed at a position facing the sub-torch 2 with respect to the central axis C1 of the main torch 1. The sub torch 39 includes a sub cathode (sub torch starting electrode) 40, a sub jacket 41 surrounding the sub cathode 40, an insulator 47 that insulates the sub cathode 40 and the sub jacket 41, and the like. The axis C2, that is, the center axis C2 of the sub-cathode 40, is arranged so as to intersect with the center axis C1 of the main torch 1, that is, the center axis C1 of the main anode 3, in front of the main anode 3 and the sub-cathode 40. .

The sub-cathode 40 is made of a material having a high melting point, such as tungsten. The sub-cathode 40 is concentrically held by a sub-jacket 41 and an insulator 47.

The auxiliary mantle 41 is provided with a hole 41a at the tip. The insulator 47 has a sub-plasma gas inlet 48 for introducing the sub-plasma gas 49 and a swirl flow forming portion 50 similar to the insulator 27 of the main torch 1.

The positive terminal of the sub torch 39 from the sub power source 42 is connected to the sub jacket 41 via the switch 44, and the negative terminal of the sub torch 39 from the sub power source 14 is connected to the sub cathode 40 via the switch 43, Further, it is connected to the negative terminal of the main power supply 7 through the switches 9 and 46.

Next, a method for plasma spraying a thermal spray material using the twin cathode type plasma spraying apparatus 101 will be described.
An inert gas that can be turned into plasma, such as argon or helium, is introduced into the main torch 1 from the main plasma gas inlet 5 as a main plasma gas 6 to form a swirling flow of the main plasma gas 6. Further, a high frequency voltage is applied between the main anode 3 and the main mantle 4 by the main power source 7 with the switch 9 opened and the switch 8 closed. As a result, a main plasma arc 16 is formed from the tip of the main anode 3 toward the opening 4 a of the main mantle 4, whereby the main plasma gas 6 is heated and becomes plasma from the opening 4 a of the main mantle 4. Released.

In addition, an inert gas that can be turned into plasma, such as argon or helium, is introduced as a secondary plasma gas 13 from the secondary plasma gas inlet 12 into the secondary torch 2 to form a swirling flow of the secondary plasma gas 13. Further, with the switches 43 and 44 opened and the switches 45 and 46 closed, a high frequency voltage is applied between the sub cathode 10 and the sub jacket 11 by the sub power source 42. As a result, a sub-plasma arc 17 is formed from the tip 10a of the sub-cathode 10 toward the hole 11a of the sub-jacket 11, whereby the sub-plasma gas 13 is heated and becomes plasma to be emitted from the hole 11a of the sub-clutch 11. Is done.

Since the center axis C1 of the main anode 3 and the center axis C2 of the sub-cathode 10 intersect outside the main torch 1 and the sub-torch 2 in front of the main anode 3 and the sub-cathode 10, the switch 9 is closed after the switch 9 is closed. When 45 and 46 are opened, a conductive path is formed by the hairpin-shaped plasma 18 from the tip 10 a of the sub-cathode 10 to the anode point of the main anode 3.

Thereafter, an inert gas that can be turned into plasma, such as argon or helium, is introduced as a secondary plasma gas 49 into the secondary torch 39 from the secondary plasma gas inlet 48 to form a swirling flow of the secondary plasma gas 49. In addition, a high frequency voltage is applied between the sub cathode 40 and the sub jacket 41 by the sub power source 42 with the switches 43 and 44 closed. As a result, a sub-plasma arc 56 is formed from the tip 40a of the sub-cathode 40 toward the hole 41a of the sub-cannula 41, whereby the sub-plasma gas 49 is heated and becomes plasma and is emitted from the hole 41a of the sub-clutch 41. Is done.

The center axis C1 of the main anode 3 and the center axis C2 of the sub-cathode 40 intersect outside the main torch 1 and the sub-torch 39 in front of the main anode 3 and the sub-cathode 40. The generated plasma intersects the hairpin-shaped plasma 18 extending from the tip 10 a of the sub-cathode 10 to the anode point of the main anode 3. In this state, when the switch 44 is opened after the switch 55 is closed, a conductive path is formed by the T-shaped plasma 18 from the tips 10a, 40a of the sub-cathodes 10, 40 to the anode point of the main anode 3, and the main path is formed. A plasma flame 23 is formed on the same axis of the torch 1.

An automatic material supply device 30 in which a gas obtained by mixing a spray material 20 a with a material supply gas 20, which is an inert gas that can be turned into plasma, such as argon and helium, is controlled by a control device 31. Sent in. The thermal spray material 20a discharged from the material inlet tube 19 through the opening 4a of the main jacket 4 is the axial center of the plasma 18 formed on the central axis C1 of the main anode 3 by the main anode 3 and the sub-cathode 10. And is melted by the plasma flame 23.

The melt 21 in which the thermal spray material 20 a is melted proceeds toward the base material 25 together with the plasma flame 23. At this time, the gas is selectively ejected from the plasma trimming portion 22 provided on the connection pipe 26 to the part of the plasma flame containing the melt immediately before the base material 25, so that an inappropriate state is obtained. The plasma flame may be changed to an appropriate shape simultaneously with the removal of the melt. As a result, a melt suitable for film formation can be deposited on the base material 25 at a more appropriate temperature, and the coating 24 of the dense thermal spray material 20a with fewer pores can be efficiently formed.

In the present embodiment, two sub-torches are provided in plasma spraying apparatus 101, but three or more sub-torches may be provided. When two or more sub-torches are provided, these sub-torches are arranged such that the central axis C2 of the electrode of the sub-torch intersects the front of the main anode 3 and at one point of the central axis C1 outside the main torch 1. Are preferably arranged on the circumference of a circle perpendicular to the central axis C1 with the intersecting point as the center. Further, when two or more sub-torches are provided in the plasma spraying apparatus 101, the sub-torches are arranged so that the central axis of each sub-torch intersects the central axis of the main torch 1 at the intersection. It is preferable.

In the plasma spraying apparatuses 100 and 101 described in the above embodiment, since the main electrode is a cathode that is a starting point of a plasma arc, the temperature becomes high and the main electrode melts or is supplied. In order to prevent the main electrode from adhering to the main electrode, the main electrode is used as an anode. Further, the spraying material discharge hole 19a is blocked by the spraying material by generating a swirling flow with the main plasma gas supplied into the main torch having the main electrode and suppressing the adhesion of the spraying material into the main torch. Is preventing.

In this way, in order to prevent adhesion of the thermal spray material to the main electrode and the main torch, in order to avoid adhesion of the thermal spray material to the main electrode, it is inclined with respect to the central axis of the main electrode where the plasma arc is formed. Although the thermal spray material was supplied from the direction to perform, it became possible to supply the thermal spray material along the central axis of the main electrode as in the plasma spraying apparatuses 100 and 101 of the present embodiment. As a result, the thermal spray material can be easily supplied to the center of the plasma flame, and the thermal spray material can be more reliably brought to the high temperature portion of the plasma flame and can be prevented from being scattered to the periphery. That is, the thermal spray material can be stably supplied to the high temperature part of the plasma flame.

The inventor of the present application supplies the thermal spray material 20a stably to the high temperature portion of the plasma flame, and the coating condition of the coating 24 formed using the supply conditions of the thermal spray material 20a that could not be handled as parameters so far. The change in properties was tested. And it tried to change the supply amount of the material supply gas 20 as supply conditions of the thermal spray material 20a. FIG. 4 is an image showing an example of a particle velocity measured by changing the supply amount Qf of the material supply gas 20. FIG. 5 is a graph showing the result of measuring the particle velocity of the thermal spray material 20a when the supply amount Qf of the material supply gas 20 is changed.

As shown in FIG. 4, when the particle velocity is measured by photographing a plasma flame at a position 100 mm from the opening 4 a of the main torch 1 with a high-speed camera or the like, the particle velocity differs depending on the supply amount Qf of the material supply gas 20. ing. When the particle velocities at the supply amounts Qf of the plurality of material supply gases 20 were measured, as shown in FIG. 5, it was found that the particle velocities increased as the supply amount Qf of the material supply gases 20 was increased.

FIG. 6 is a cross-sectional view showing the coating 24 formed by changing the supply amount Qf of the material supply gas 20 between 1.0 l / min and 10.0 l / min.
As shown in FIG. 6, when the supply amount of the material supply gas 20 is 10.0 l / min, the coating 24 becomes thinner than when the supply amount of the material supply gas 20 is 1.0 l / min. From this result, it can be seen that the thickness can be changed as a characteristic of the film 24 formed by controlling the supply amount Qf of the material supply gas 20. That is, the supply amount of the material supply gas 20 is increased to form the thin film 24 faster, or the supply amount of the material supply gas 20 is decreased to form the thick film 24. Is possible.

Further, the inventor measured the hardness of the coating 24 by changing the supply amount Qf of the material supply gas 20.
FIG. 7 is a graph showing the relationship between the supply amount Qf of the material supply gas 20 and the hardness of the coating 24 to be formed. As shown in FIG. 7, when the supply amount Qf of the material supply gas 20 is large, the hardness of the coating 24 is lower than when the supply amount Qf of the material supply gas 20 is small. For this reason, the inventor made it possible to change the hardness as a characteristic of the film 24 formed by controlling the supply amount Qf of the material supply gas 20. That is, the supply amount Qf of the material supply gas 20 is increased to form the coating 24 with low hardness more quickly, or the supply amount Qf of the material supply gas 20 is decreased to form the coating 24 with high hardness. Made possible.

According to the plasma spraying apparatuses 100 and 101 of the present embodiment, the supply of the material supply gas 20 that forms the coating 24 on the substrate 25 by spraying the material supply gas 20 including the sprayed material 20a along the central axis of the main anode 3. Since the control device 31 for controlling the amount is provided, the supply amount of the material supply gas 20 as the supply condition of the thermal spray material 20a when reaching the substrate 25 by controlling the supply amount of the material supply gas 20 is controlled. It is possible to form the film 24 by making it different. Then, it is possible to control the supply amount of the material supply gas 20 by the control device 31 to form the film 24 having different characteristics, that is, the thickness and hardness of the film 24.

The control of the automatic material supply device 30 by the control device 31 is, for example, a database based on data as shown in the graphs of FIGS. 5 and 7, that is, the thickness or hardness of the film 24 to be formed and the supply amount of the material supply gas 20. Can be easily controlled by generating a characteristic database in association with and controlling the supply amount of the material supply gas 20 based on the thickness or hardness of the film 24 to be formed and the characteristic database. It is.
At this time, at least one of the particle velocity and the particle temperature of the thermal spray material 20a sprayed on the substrate 25 is observed by a CCD camera or the like, and the control device is based on the observation result and the thickness or hardness of the coating 24 to be formed. When the supply amount of the material supply gas 20 is controlled by 31, more accurate control is possible, and the coating 24 having a desired thickness or hardness can be formed.

FIG. 8 is a diagram showing a schematic configuration of the plasma spraying apparatus 102 in which the main torch 1 and the sub torch 2 are integrated.
In the above embodiment, the plasma spraying apparatuses 100 and 101 in which the main torch 1 and the sub torch 2 are separately separated have been described. However, as shown in FIG. It may be an integrated plasma spraying apparatus 102 of the main torch 1 and the sub torches 2 and 39 in which the sub torches 2 and 39 are integrally provided via the insulator 60 on the outlet side.

Further, the above embodiment is for facilitating the understanding of the present invention, and is not for limiting the interpretation of the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

1 main torch, 2 sub torch, 3 main anode, 4 main mantle, 4a opening,
4b taper part, 5 main plasma gas inlet, 6 main plasma gas, 7 main power supply,
8,9 switch, 10 secondary cathode, 10a tip of secondary cathode, 11 secondary jacket,
11a hole, 12 secondary plasma gas inlet, 13 secondary plasma gas, 14 secondary power source,
15 switches, 16 main plasma arcs, 17 secondary plasma arcs, 18 plasmas,
19 Material feeding pipe, 19a Spraying material discharge hole, 20 Material supply gas, 20a Spraying material,
21 melt, 22 plasma trimming section, 23 plasma flame, 24 coating, 25 substrate,
26 connecting pipe, 27, 28 insulator, 30 automatic material supply device, 31 control device,
39 sub torch, 40 sub cathode, 40a tip of sub cathode, 41 sub mantle, 41a hole,
42 Sub power supply, 43, 44, 45, 46 switch, 47 insulator,
48 sub-plasma gas inlet, 49 sub-plasma gas, 50 swirl flow forming section,
51 gas annular chamber, 52 swirl flow forming hole, 53 inner wall, 55 switch,
56 sub-plasma arc, 60 insulator, 100 composite torch type plasma spraying device,
101 Twin cathode type plasma spraying device, 102 Integrated plasma spraying device,
C1 center axis of main anode, C2 center axis of sub-cathode

Claims (9)

A main torch having a main anode having a material feed pipe for feeding a thermal spray material along a central axis together with a material supply gas for feeding the thermal spray material, and introducing a main plasma gas along the central axis When,
A secondary torch comprising a secondary cathode whose central axis intersects the central axis of the primary anode;
Have
A plasma arc formed between the main anode and the sub-cathode;
The main plasma gas introduced along the central axis of the main anode;
The material is applied to the plasma flame formed along the central axis of the main anode by the sub-plasma gas introduced along the central axis of the sub-cathode and toward the central axis of the main anode. In the plasma spraying apparatus in which the thermal spray material is fed together with the material supply gas from a feed pipe, the thermal spray material is melted and sprayed onto a base material to form a coating of the thermal spray material,
A plasma spraying apparatus comprising a supply amount control unit for controlling a supply amount of the material supply gas. 2. The plasma spraying apparatus according to claim 1, wherein the supply amount control unit controls the supply amount of the material supply gas independently of the supply amount of the thermal spray material. The plasma spraying apparatus according to claim 1 or 2, wherein the supply amount control unit controls the supply amount of the material supply gas so as to change characteristics of the film to be formed. 4. The plasma spraying apparatus according to claim 3, wherein the characteristic of the coating is a thickness of the coating to be formed. 5. The plasma spraying apparatus according to claim 4, wherein the supply amount of the material supply gas is reduced by the control of the supply amount control unit as the thickness of the coating increases. 4. The plasma spraying apparatus according to claim 3, wherein the characteristic of the coating is a hardness of the coating to be formed. The plasma spraying apparatus according to claim 6, wherein the higher the hardness of the coating, the smaller the supply amount of the material supply gas is controlled by the supply amount control unit. Generating a characteristic database in which the characteristic of the coating is associated with the supply amount of the material supply gas;
The supply amount control unit controls the supply amount of the material supply gas based on the characteristic of the film to be formed and the characteristic database. Plasma spraying equipment.
The supply amount control unit observes at least one of a particle velocity and a particle temperature of the sprayed material sprayed on the base material, and supplies the material based on an observation result and the characteristics of the coating to be formed. The plasma spraying apparatus according to any one of claims 3 to 7, wherein a gas supply amount is controlled.

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