JP2001181817A - Thermal spraying method and thermal spraying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a smooth thermal spraying work by avoiding adhesion of a molten thermal spraying material to a flame forming unit (an expansion nozzle) to eliminate any defective operation caused by the stuffing of the thermal spraying material. SOLUTION: A high-speed flame F is formed toward a surface 11 to be thermally sprayed by a flame forming unit 2, a thermal spraying material M is charged in the middle of the high-speed flame F from a thermal spraying material charging unit 3, and the thermal spraying material M is adhered to the surface 11 to be thermally sprayed to form a spray deposit 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal spraying method and a thermal spraying apparatus for depositing a thermal spraying material on a base material surface (sprayed surface) by using high-speed flame spraying to form a coating of the thermal spraying material. The present invention relates to an apparatus which eliminates an operation failure due to clogging and enables a smooth spraying operation to be performed.

[0002]

2. Description of the Related Art As a technique for coating a surface of a base material such as a metal with ceramics or another metal, there is a technique called high-velocity flame spraying (HVOF). Is formed while the thermal spraying material is carried at a high speed by the high-speed frame, and is applied to the surface of the base material (thermally sprayed surface). Then, by spraying the sprayed material on the sprayed surface at a high speed in this manner, pores are hardly generated in the coating, and a coating having high hardness can be obtained.

FIG. 3 is a sectional view schematically showing a conventional thermal spraying apparatus X used for performing high-speed flame spraying. The thermal spraying apparatus X includes a combustion chamber 101 to which fuel and oxygen such as propylene, hydrogen, and propane are supplied, an ignition device 102 for igniting fuel in the combustion chamber 101, and a throttle unit 1
An expansion (divergence) nozzle 104 connected to the combustion chamber 101 via a gas supply line 03 and a thermal spraying material supply device 105 for supplying a thermal spraying material to the upstream side of the expansion nozzle 104. In the thermal spraying apparatus X configured as described above, the fuel in the combustion chamber 101 is ignited by the igniter 102 and burned, and the combustion gas is accelerated while passing through the expansion nozzle 104 from the throttle section 103, so that the Mach 2 -6 high-speed frames F are emitted. Then, by spraying the thermal spray material M from the thermal spray material supply device 105 into the expansion nozzle 104 while directing the high-speed frame F toward a thermal spraying surface (not shown), the thermal spray material M is carried at high speed on the high-speed frame F. , And strikes and adheres to the sprayed surface to form a coating.

[0004]

By the way, in the high-speed flame spraying, the granular thermal spray material M is softened by the heat of the high-speed frame F while being carried on the high-speed frame F,
By hitting the sprayed surface with this softness, the adhesion to the sprayed surface is increased, and a stronger film is formed.
In the conventional thermal spraying apparatus X shown in FIG. 3, since the thermal spraying material M from the thermal spraying material supply device 105 is injected into the expansion nozzle 104, the thermal spraying material M is injected into the high-speed frame F. When a material having a high melting point such as (melting point is about 2500 ° C.) is used as the thermal spray material M, the thermal spraying material M is injected from the expansion nozzle 104 without melting, but has a low melting point such as aluminum (melting point is about 600 ° C.). When the material is the thermal spray material M, the thermal spray material M is melted before being injected from the expansion nozzle 104. In this case, not only does the melt of the thermal spray material M adhere to the inner surface of the expansion nozzle 104 and lowers the yield, but also the melt adheres and accumulates near the outlet of the expansion nozzle 104 to block the outlet portion, There is a problem that a malfunction of the thermal spraying device is caused and a smooth thermal spraying operation cannot be performed.

[0005] Even high melting point materials such as ceramics having a small particle size may be melted before being injected from the expansion nozzle 104, and a particle size distribution including such a small particle size may be obtained. If a product having a wide width is used, clogging of the expansion nozzle 104 occurs as in the case described above. On the other hand, it is possible to use a product with a specified particle size distribution (a product excluding a product with a small particle size), but a product with a specified particle size distribution is expensive, which leads to an increase in cost. Absent.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. In performing high-speed flame spraying, even when a low-melting substance or a material having a small particle diameter is used as a thermal spraying material, a molten material of the thermal spraying material forms a frame forming portion ( It is an object of the present invention to provide a thermal spraying method and a thermal spraying apparatus which can prevent the thermal spraying material from adhering to an expansion nozzle, and eliminate a malfunction due to the clogging of the thermal spraying material, thereby enabling a smooth thermal spraying operation.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a high-speed frame is formed toward a thermal spraying surface, and a thermal spray material is supplied in the middle of the high-speed frame to perform thermal spraying. Adopts technology to attach thermal spray material to the surface. In this thermal spraying method, the thermal spray material is injected in the middle of the high-speed frame without being injected inside the frame forming portion, so that the thermal spray material does not melt and adhere to the frame forming portion,
By avoiding an operation failure due to the clogging of the thermal spray material while improving the yield, it is possible to carry out a smooth thermal spraying operation. In particular, a low-melting substance or a material having a small particle size can be used as a thermal spray material, which makes it possible to broaden the application range of the thermal spray material and reduce costs.

According to a second aspect of the present invention, in the thermal spraying method of the first aspect, a technique is applied in which the thermal spray material falls into the high-speed frame by being dropped from above the high-speed frame.
In this thermal spraying method, the thermal spray material is sucked into the high-speed frame and carried by dropping the thermal spray material from above the high-speed frame having a large dynamic pressure.
It is possible to simplify the thermal spraying operation and to improve the efficiency of the operation.

The invention according to claim 3 is the invention according to claim 1 or 2
In the thermal spraying method, a technique is applied in which two or more types of thermal spraying materials are charged into a high-speed frame and the composition of the deposits on the thermal spraying surface is changed by changing the mixing ratio. In this thermal spraying method, since the composition of the deposit is changed by changing the mixing ratio of two or more types of thermal spraying materials supplied to the high-speed frame,
It is possible to easily change the composition change of the deposit,
In addition, it is possible to easily produce a functionally graded material by changing the composition of the deposit during thermal spraying.

[0010] The invention according to claim 4 employs a technology including a frame forming section for forming a high-speed frame, and a thermal spray material charging section for charging a thermal spray material into the high-speed frame ejected from the frame forming section. In this thermal spraying device, the thermal spray material is injected from the thermal spray material input portion into the injected high-speed frame, so that the thermal spray material does not melt and adhere to the frame forming portion, and the thermal spray material is clogged while improving the yield. It is possible to carry out a smooth thermal spraying operation by avoiding an operation failure due to the above. In particular, a low-melting substance or a material having a small particle size can be used as a thermal spraying material, so that the application range of the thermal spraying material can be expanded and the cost can be reduced.

According to a fifth aspect of the present invention, in the thermal spraying apparatus of the fourth aspect, a technique in which two or more thermal spraying material charging portions are arranged is applied. In this thermal spraying device, since two or more thermal spraying material input sections are arranged, it is possible to easily change the composition of the deposit by inputting different thermal spraying materials from each thermal spraying material inputting section to the high-speed frame.

According to a sixth aspect of the present invention, in the thermal spraying apparatus of the fifth aspect, a technique is applied in which each of the two or more arranged spraying material charging sections has an adjusting section for adjusting the amount of the spraying material. In this thermal spraying apparatus, the mixing ratio of the thermal spraying material is changed when different thermal spraying materials are charged together in order to adjust the amount of the thermal spraying material to be adjusted by the adjusting unit for each of the two or more thermal spraying material charging portions. Thus, the composition of the deposit can be easily changed, and by changing the composition of the deposit during thermal spraying, the functionally gradient material can be easily produced.

[0013]

1 and 2 show an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a side sectional view schematically showing a thermal spraying apparatus 1 for performing a thermal spraying method according to the present invention. As shown in FIG. 1, the thermal spraying apparatus 1 includes a frame forming section 2 for forming a high-speed frame F, and a frame forming section 2.
And a thermal spray material input section 3 for inputting the thermal spray material M into the high-speed frame F that has been injected.

The flame forming section 2 is provided with a combustion chamber 4 to which fuel and oxygen such as propylene, hydrogen, and propane are supplied, similarly to the thermal spraying apparatus X shown in FIG. 3 (a fuel and oxygen supply mechanism is not shown). An ignition device 5 for igniting fuel in the combustion chamber 4, and a throttle 6 formed at an outlet of the combustion chamber 4
And an expansion (divergence) nozzle 7 connected to the combustion chamber 4 via the throttle section 6. Then, the fuel and oxygen supplied into the combustion chamber 4 are ignited by the ignition device 5 and burned, so that the combustion gas is accelerated while passing through the expansion nozzle 7 from the throttle unit 6 as shown by an arrow in FIG. Two to six high-speed frames F are ejected from the expansion nozzle 7.

The thermal spraying material feeding section 2 holds a granular thermal spraying material M and feeds the thermal spraying material M by a predetermined amount, and guides the thermal spraying material M sent from the thermal spraying material supply device 8 to above the high-speed frame F. And a dropping nozzle 9 for dropping. The injection nozzle 9 is arranged near the outlet of the expansion nozzle 7, and inputs the thermal spray material M from above the high-speed frame F immediately after the injection from the expansion nozzle 7.

A thermal spraying method according to the present invention will be described using the thermal spraying apparatus 1 configured as described above. First, the frame forming unit 2 is driven to form the high-speed frame F, and the high-speed frame F is set to the sprayed surface 11 of the base material 10. Next, the thermal spray material supply device 8 of the thermal spray material input section 2
Is driven to feed the spray material M from the injection nozzle 9 to the high-speed frame F.
In the middle of. At this time, since the high-speed frame F is ejected at Mach 2 to 6 and has a high dynamic pressure, a state similar to the case where the periphery thereof is evacuated occurs. Therefore, the granular thermal spray material M that falls from the injection nozzle 9 to the high-speed frame F is sucked into the high-speed frame F and enters the high-speed frame F.
It does not fall off and does not fly nearby, and the possibility of contamination to the surroundings is extremely low.

The thermal spray material M sucked into the high-speed frame F is carried toward the thermal spraying surface 11 and hits and adheres to the thermal spraying surface 11. By laminating the adhesion of the thermal spray material M, a coating 12 is formed on the thermal spray surface 11 as shown in FIG. Note that the direction of the frame forming portion 2 (expansion nozzle 7) and the
Is moved, the adhesion position of the thermal spray material M is moved, and a wide range of coating film can be continuously formed.

As described above, since the thermal spray material M is not injected into the expansion nozzle 7 but is injected in the middle of the high-speed frame F ejected from the expansion nozzle 7, the thermal spray material M is melted and A stable spraying operation can be performed without causing malfunction due to the adhesion at the outlet of the nozzle. In particular, when a low melting point material such as aluminum or a product having a wide particle size distribution including a small particle size is used as the thermal spray material M,
The application range of the thermal spray material M can be expanded without causing any trouble due to the melting of the thermal spray material M.

FIG. 2 is a side sectional view schematically showing another embodiment of the thermal spraying apparatus. This thermal spraying device 13 is shown in FIG.
In addition to the above, a flame forming part 2 is provided, and two thermal spray material introduction parts 14 and 14a are provided. The frame forming unit 2 is as described above, and the description is omitted. Each of the thermal spray material input sections 14 and 14a is provided with the thermal spray material supply device 1.
Control device 1 which includes input nozzles 5 and 15a, input nozzles 16 and 16a, and variable valves (adjustment units) 17 and 17a, and instructs the operation of the variable valves (adjustment units) 17 and 17a.
Eight.

The spraying material supply devices 15 and 15a and the injection nozzles 16 and 16a are the same as those shown in FIG. The injection nozzles 16 and 16a are arranged side by side along the emission direction of the high-speed frame F, as shown in FIG. The variable valves 17, 17a are provided with sprayed materials Ma, M per unit time to the respective injection nozzles 16, 16a.
This adjusts the supply amount of b and operates based on an instruction from the control device 18 or a manual operation by an operator. Therefore, by adjusting the operation amounts of the variable valves 17, 17a, the mixing ratio of the thermal spray materials Ma, Mb is determined.

A thermal spraying method according to the present invention will be described using the thermal spraying apparatus 13 configured as described above. First, the frame forming unit 2 is driven to set the high-speed frame F toward the sprayed surface 11 of the base material 10. Next, the thermal spray material supply devices 15 and 15a of the thermal spray material input sections 14 and 14a are driven to supply the thermal spray material Ma from the charging nozzle 16 and the thermal spray material Mb from the charging nozzle 16a to the middle of the high-speed frame F. The thermal spray materials Ma and Mb are transported while being mixed in the high-speed frame F, and also collide with and adhere to the thermal spray surface 11. Thus, the coating 19 is formed with a composition in which the thermal spray materials Ma and Mb are mixed at a predetermined ratio, and the thermal spray material M
The composition of the coating 19 can be set arbitrarily by changing the mixing ratio of a and Mb.

The mixing ratio of the thermal spray materials Ma and Mb may be changed during the thermal spraying operation. For example, when the base material 10 is a metal, the thermal spray material Ma is a ceramic, and the thermal spray material Mb is a metal, At the beginning of the thermal spraying on the thermal spraying surface 11, the thermal spray material M
By spraying with only b (metal) or by increasing the mixing ratio of the thermal spray material Mb, the adhesion (adhesion) with the base material 10 is improved,
The mixing ratio of the thermal spraying material Ma (ceramics) is gradually increased in the process of laminating the deposits.
It is also possible to form a coating (so-called functionally graded material) that improves heat resistance by increasing only a or the mixing ratio of the thermal spray material Ma.

It is also possible to change the mixing ratio of the sprayed materials Ma and Mb while moving the direction of the expansion nozzle 7 and the base material 10 during the spraying operation. This makes it possible to perform a series of operations when forming a film whose composition is changed in some regions. Moreover, by smoothly changing the mixing ratio, a seam of the coating is not formed, and a decrease in the coating strength can be prevented.

The various shapes, combinations, and the like of the constituent members shown in the above embodiment are merely examples, and can be variously changed based on design requirements without departing from the spirit of the present invention. For example, in the illustrated thermal spray material charging section 8 or the like, the thermal spray material M or the like is simply dropped from above the high-speed frame F. Instead of this, the thermal spray material M or the like is sprayed toward the high-speed frame F. Is also good. Also,
As shown in FIG. 2, it goes without saying that three or more thermal spraying material charging sections may be provided instead of being provided.

[0025]

As described above, in the thermal spraying method according to the first aspect, since the thermal spraying material is injected in the middle of the high-speed frame without being injected inside the frame forming portion, the thermal spraying material is melted to form the frame. By avoiding malfunction due to clogging of the sprayed material while improving the yield without adhering to the parts, a smooth spraying operation can be performed. In particular, a low-melting substance or a material having a small particle size can be used as a thermal spray material, so that the range of application of the thermal spray material can be widened and the cost can be reduced.

In the thermal spraying method according to the second aspect, the thermal spraying material is dropped from above the high-speed frame having a large dynamic pressure, so that the thermal spraying material is sucked and carried into the high-speed frame. In addition, it is possible to simplify the thermal spraying operation and improve the efficiency of the operation. In the thermal spraying method according to the third aspect, since the composition of the deposit is changed by changing the mixing ratio of the two or more types of thermal spraying materials supplied to the high-speed frame, the composition change of the deposit can be easily changed. In addition, the gradient functional material can be easily manufactured by changing the composition of the deposit during thermal spraying.

In the thermal spraying apparatus according to the fourth aspect, since the thermal spraying material is injected from the thermal spraying material input portion into the high-speed frame that has been injected, the thermal spraying material does not melt and adhere to the frame forming portion, thereby improving the yield. By avoiding the malfunction due to the clogging of the spray material while achieving the above, a smooth spraying operation can be performed. In particular, a low-melting substance or a material having a small particle size can be used as a thermal spray material, so that the range of application of the thermal spray material can be widened and the cost can be reduced.

In the thermal spraying apparatus according to the fifth aspect, since two or more thermal spraying material charging portions are arranged, different thermal spraying materials are charged from each thermal spraying material charging portion to the high-speed frame, so that the composition of the deposit can be easily changed. can do. In the thermal spraying apparatus according to claim 6, in order to adjust the input amount of the thermal spraying material by the adjusting unit for each of the two or more thermal spraying material input sections, when the different thermal spraying materials are injected together, the mixing of the thermal spraying material is performed. By changing the ratio, the composition of the deposit can be easily changed, and by changing the composition of the deposit during thermal spraying, the functionally gradient material can be easily produced.

[Brief description of the drawings]

FIG. 1 is a side sectional view schematically showing an embodiment of a thermal spraying apparatus according to the present invention.

FIG. 2 is a side sectional view schematically showing another embodiment of the thermal spraying apparatus.

FIG. 3 is a side sectional view showing a conventional thermal spraying apparatus.

[Explanation of symbols]

 F High-speed frame M, Ma, Mb Thermal spray material 1, 13 Thermal spraying device 2 Frame forming unit 3, 14, 14a Thermal spray material input unit 7 Expansion nozzle 9, 16, 16a Input nozzle 10 Base material 11 Thermal spray surface 12, 19 Coating (with Kimono) 17, 17a Variable valve (adjustment part)

Claims (6)

[Claims] 1. A thermal spraying method, comprising: forming a high-speed frame toward a thermal spraying surface, charging a thermal spraying material in the middle of the high-speed frame, and attaching the thermal spraying material to the thermal spraying surface. 2. The thermal spraying method according to claim 1, wherein the thermal spraying material is dropped into the high-speed frame by being dropped from above the high-speed frame. 3. The composition according to claim 1, wherein two or more kinds of thermal spraying materials are charged into the high-speed frame, and a composition of the deposits on the thermal spraying surface is changed by changing a mixing ratio thereof. Spray method. 4. A thermal spraying apparatus comprising: a frame forming section for forming a high-speed frame; and a thermal spraying material charging section for charging a thermal spraying material into the high-speed frame injected from the frame forming section. 5. The thermal spraying apparatus according to claim 4, wherein two or more of the thermal spray material input sections are arranged. 6. The thermal spraying apparatus according to claim 5, wherein each of the two or more thermal spray material input sections includes an adjusting section for adjusting an amount of injected thermal spray material.