JP2010242204A - Impact sintering and coating method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive method for obtaining an excellent coating having functionality satisfying demands by performing impact sintering and coating at or below the temperature at which coated powder is transformed, decomposed, sublimated or evaporated, since a frame temperature becomes 2,200°C to 3,400°C in conventional flame spraying, the powder is easily melted, deformed, decomposed, sublimated and evaporated and thus a deformed coating different from the coated powder or the coating of a different composition is obtained in the case of manufacturing a ceramic coating by impact sintering and coating by using oxide, nitride, carbide, boride ceramics or fluoride powder. <P>SOLUTION: After the combustion chamber of a gun, powder and a combustion gas are turned from a supply nozzle to the shaft of a frame, and the combustion gas and slurry-like fine powder are injected. Oxygen equivalent introduced to the combustion chamber is lowered, the capacity of the combustion gas introduced from a powder supply nozzle is adjusted, and the temperature of fine powder present in the frame is controlled. Also, acceleration is performed by a combustion generation gas, the impact sintering and coating are performed, and the coating having demanded function characteristics and adhesion is formed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an impact-sintering coating method and apparatus using a coating made of ceramics and the like having functions such as heat resistance, heat transfer, electrical insulation and corrosion resistance, and fine powder.

Metals / alloys and ceramics change their properties due to changes in temperature. In a surface modification process where the treatment temperature is high, the material properties at room temperature are transformed by the high temperature treatment and changed to other properties. In particular, in the conventional thermal spraying process, it is difficult to perform thermal spraying at a temperature below 4000 ° C to 30000 ° C and gas thermal spraying method 2200 ° C to 3400 ° C in plasma spraying by electric spraying. There is a strong demand for a method in which coating is performed by changing the coating composition by controlling accurately at a low temperature at which the material does not transform. In addition, when the thermal spraying powder is 10 μm or less, particularly 5 μm or less, a normal powder supply apparatus cannot be stably supplied because it is intermittently supplied or causes a bridge and clogs the passage.

Japanese Patent Laid-Open No. 10-60617 JP 2006-108178 JP JP 2006-104496 JP

For the coating process, conventional plasma spraying using working gases such as Ar + hydrogen, Ar + nitrogen, He + hydrogen has a flame center temperature of 5000 ° C to 30000 ° C. On the other hand, in conventional flame spraying using fuel and oxygen, oxygen / kerosene, air / kerosene, oxygen / hydrogen, oxygen / propylene, oxygen / propane, oxygen / ethylene, oxygen / acetylene, oxygen / natural gas mixed gas To generate heat. The flame spraying temperature is 2200 ° C to 3400 ° C, and is a continuous combustion reaction, so it is very difficult to control the temperature below this.

As for the powder supply device, when a material having low thermal conductivity such as ceramics is instantaneously heated and melted, it is better that the particle size of the powder is fine. Further, when the coating powder is fine, the surface roughness of the film is fine, and there is an advantage that the subsequent surface finishing step can be omitted. However, fine powder with a particle size of 0.1 μm to 10 μm is easy to agglomerate and is mixed with a solvent to form a slurry. Flow and stable feeding are difficult and uniform film formation is impaired.

As for the coating material, there are oxide ceramics which transform at 2200 ° C. or less of flame spraying, so that there is a drawback that the film characteristics change and the function is impaired. In addition, in plasma spraying, there are oxide ceramics that melt from 5000 ° C. to 30000 ° C., decompose, and evaporate. Therefore, there is a drawback that the function of the film characteristics is not sufficiently satisfied.

Similarly, in the case of flame spraying, nitride ceramics are easily sublimated and decomposed at a flame temperature of 2200 ° C. or less, and it is almost impossible to coat them.

Carbide-based ceramics are difficult to be transformed and decomposed by flame spraying or plasma spraying.

Fluoride easily sublimes and evaporates by flame spraying and plasma spraying and is therefore difficult to coat.

For example, if the flame temperature is 30000 ° C in plasma spraying, and if a fine powder of oxide Al2O3 or βSiO2 is introduced, it will be easily transformed or melted and decomposed, making it very difficult to coat the substrate. is there. In addition, nitrides AlN, Si3N4, BN, and carbide SiC with low binding energy, which have a relatively low melting point and are susceptible to sublimation decomposition, decompose and are very difficult to coat. In addition, since the upper limit of the flame temperature in the gas spraying method is about 3400 ° C., fluorides such as AlF3, HfF4 and ZrF2 have a low boiling point and are sublimated at the flame temperature in flame spraying, so that it is difficult to coat them.

The impact sintered coating method according to the present invention is burned in a combustion chamber using oxygen / kerosene, air / kerosene, oxygen / hydrogen, oxygen / propylene, oxygen / propane, oxygen / ethylene, oxygen / acetylene, oxygen / natural gas. And generate a frame. In the combustion of CmHn + (m + n / 2) O2 → mCO2 + n / 2H2O, the amount of CmHn is less than (m + n / 2) of oxygen equivalent to 1 mole of CmHn hydrocarbon, and CmHn remains without burning. To reduce the calorific value and the frame temperature. (See Fig. 3) The gas combusted in the combustion chamber is narrowed in cross section at the gun inlet, thus accelerating the combustion flame. (See Fig. 4) Also, compressed air is allowed to flow from the gun inlet along the inner surface of the gun to prevent the charged powder from adhering. (See Fig. 5) At the combustion chamber, attach the gun tip tube to the tip of the gun, and place the powder supply nozzle at two positions 180 ° toward the cylinder axis of the tip tube or at four positions at 90 ° with respect to the gun axis. And install with an inclination. (refer graph1)

In the powder supply apparatus, the fine powder forms a bridge in a narrow conveyance tube and cannot be stably supplied. Therefore, the fine powder is conveyed in the form of a slurry. A ceramic fine powder with a particle size of 0.1 μm to 10 μm is stirred with an ultrasonic oscillator using ethyl alcohol, methyl alcohol or kerosene as a solvent and mixed uniformly to form a slurry. Therefore, it does not become a lump and the density of the slurry is eliminated, and a uniform film can be formed. Even if powder having a particle size of 10 μm or more is present, it can be made into a slurry. It is sent to the tube with a pump, and one or two kinds of acetylene gas, methylene, ethylene, methane, ethane, butane, propane, or propylene are sent from the Y-shaped union of the tube and mixed. These gases are cooled and kept at room temperature through a gas cooling device before being sent to the Y-shaped union. By mixing a cold gas into the slurry powder, these acetylene and methylene gases injected into the combustion flame are in an oxygen-deficient state and do not burn, that is, do not generate heat. Therefore, the temperature rise of the powder itself is suppressed and the sublimation temperature and evaporation temperature are not increased.

As nitride ceramics for coating, BN, AlN, Si3N4, and NbN sublimate as the temperature rises, so it is desirable to coat at a sublimation temperature or lower.

As carbide ceramics for coating, SiC transforms with increasing temperature, and further decomposes, so it is desirable to coat at or below the transformation temperature.

As boride ceramics, MoB decomposes with increasing temperature, so it is desirable to coat at or below the decomposition temperature.

As fluorides, AlF3, HfF4, and ZrF2 sublimate as the temperature rises, so it is desirable to coat them at or below the sublimation temperature. Further, since MgF2, CaF2, BaF2, GaF3, YF3, and ZnF2 evaporate at 2500 ° C. or lower, it is desirable to coat them at an evaporation temperature or lower.

If the amount of oxygen in the fuel is greater than the theoretical oxygen content for the impact sintering coating, the combustion gas contains oxygen and reacts with acetylene, methane, ethane, butane, propane, propylene, or alcohol conveyed from the powder supply nozzle. Fever. On the other hand, if the amount of oxygen is less than the (m + n / 2) theoretical oxygen amount relative to the CmHn fuel, non-combustible fuel is contained and the temperature is lowered. In addition, since the acetylene, methylene, ethylene, methane, ethane, butane, propane, propylene, and alcohols conveyed from the powder supply nozzle do not burn, the frame is cooled. Also, when alcohols are vaporized without burning, they take heat of vaporization from the surroundings and exert a cooling effect.
Reference: In the case of kerosene, C12H26 + 37 / 2O2 → 12CO2 + 13H2O where the oxygen amount is less than 37/2 mol.

Other impact sintering coating conditions include the total amount of combustion gas and oxygen such as kerosene or hydrocarbons, the distance from the gun of the powder supply nozzle in the gun tip tube, acetylene, methane, ethane, butane, propane mixed in the slurry, or There are propylene supply amount and slurry supply amount, and the heating particle temperature, the atmosphere temperature of the flame and the heating particle speed are controlled by the balance between them, and it is built into the film configuration that meets the target.

For example, when using a kerosene / oxygen mixture as fuel, the shock sintering coating conditions are: oxygen gas pressure 0.5 to 1.5 MPa, flow rate 400 to 1900 liters / min, kerosene pressure 0.4 to 1.4 MPa, flow rate 0.2 to 0.5 liters / minute, compressed air pressure 0.2-1.5 MPa, 250-2000 liters / minute, slurry powder feed rate. 100-900 grams / minute, C2H2 (acetylene) pressure 0.1-1.5 MPa, 20-600 liters / minute Make minutes. The distance to the workpiece is 70mm to 400mm from the tip of the gun tip.

When using an acetylene / oxygen mixture as the fuel, the impact sintering coating conditions are as follows: oxygen gas pressure 0.15-0.3 MPa, flow rate 30-70 liters / minute, acetylene pressure 0.10-0.24 MPa, flow rate 15-55 liters / minute Min, compressed air pressure to 0.2-1.5MPa, 100-1500L / min, slurry powder feed rate. 100-900g / min, C2H2 (acetylene) pressure 0.3-1.5MPa, 60-600L / min . The distance to the workpiece should be 50mm to 300mm from the tip of the gun tip.

In the case of oxides, nitrides, carbides, borides, and fluorides that are easily sublimated, decomposed, and evaporated in the impact sintered coating, the flame temperature is lowered and the temperature is controlled with high precision, enabling the impact sintered coating.

With a simple powder supply system, the solvent and fine powder used can be supplied in the form of a uniform slurry by ultrasonic vibration. An impact-sintered coating film using fine powder can be formed, and the surface roughness can be made finer, and the surface finishing step can be omitted. Therefore, it was possible to suppress the increase in cost.

Theoretically, the combustion reaction of hydrocarbons and oxygen in the fuel results in CmHn + (m + n / 2) O2 → mCO2 + n / 2H2O, and CmHn
If the oxygen equivalent is less than (m + n / 2) moles per mole, CmHn remains unburned. As a result, the combustion energy decreases. (See Fig. 3) This unburned CmHn gas reacts with the oxygen in the compressed air coming from the gun inlet, but flows along the inner surface of the gun, so the area of contact with the CmHn gas is small and the calorific value is very small. (See Figure 5)
In a solid-liquid-gas three-phase mixture consisting of slurry powder and hydrocarbons such as C2H2 and C2H4, the hydrocarbons in these are injected into the oxygen deficient combustion flame, and therefore do not generate heat due to incomplete combustion. Moreover, since the coating powder is covered with gas, heat transfer from the combustion flame coming from the combustion chamber is hindered. Furthermore, the alcohol as the solvent of the slurry is vaporized and loses heat of vaporization to lower the temperature. (See Figure 5)
Impact sintering energy: E, powder particle mass: m, powder particle mass: v, residence time: τ, temperature: Tp (constant pressure), specific heat: Cp (constant pressure), heat of dissolution: Lp, E = ^{τ τ} ₀ Cp (Tp) dTp + mLp + 1/2 mv ² holds. That is, as the particle temperature, residence time, heat of dissolution, and powder particle mass increase, the coating powder melts well and tends to adhere. However, in the impact sintering method of the present invention, in order to coat at a temperature below the sublimation temperature, evaporation temperature, and transformation temperature, the flame temperature is lowered to reduce the heat transfer from the combustion flame to a solid-liquid-gas three-phase. Then, the particle temperature is lowered, in other words, the temperature of the coating powder is lowered (Tp is lowered), and it is not dissolved (Lp = 0), and the particle velocity V is increased to increase the adhesion. (See Fig. 5) On the other hand, if the nozzle cross-sectional area s, the frame speed v, the combustion chamber cross-sectional area S, and the speed V of the gun nozzle, SV = sv and v∝S / s = (R ² / r ² ) area Proportional to ratio and faster. That is, the flame speed can be increased by increasing the inner diameter of the combustion chamber and reducing the inner diameter of the gun. (See Figure 4)

Schematic diagram of impact sintered coating gun for implementing the impact sintered coating method of the present invention Schematic diagram of slurry powder and combustion gas supply device for carrying out the impact sintering coating method of the present invention Conceptual diagram of temperature control for carrying out the impact sintering coating method of the present invention Schematic diagram of combustion flame acceleration for carrying out the impact sintered coating method of the present invention Conceptual diagram of supply of three-phase mixed powder for carrying out the impact sintered coating method of the present invention

As shown in the schematic diagram of FIG. 1, the impact sintering coating apparatus has a combustion chamber 1, introduces oxygen gas from an oxygen passage 2, and uses kerosene, acetylene, propylene, propane, ethylene, natural gas, etc. from a fuel passage 3. Introduce combustion gas and liquid fuel. Fuel and oxygen are mixed in the burner 4, introduced into the combustion chamber, and burned when ignited. The frame passes through a gun nozzle 5 with a reduced area. The frame is then accelerated. It reaches the tip tube 6 attached to the tip of the gun nozzle 5. The gun nozzle 5 has a compressed air passage 7 therein, and the compressed air flows in a laminar flow on the inner surface of the tip tube 6 by the compressed air injection ring 8 so that the powder does not adhere to the inner surface of the gun tip tube 6. ing.

A solid-liquid-gas three-phase mixture of slurry powder and acetylene, methylene, ethylene, methane, ethane, butane, propane, or propylene gas is introduced into the tip tube 6 from a three-phase injection passage 9, and a powder supply nozzle 10. Is inclined toward the axis of the tip tube 6. The powder is supplied from the three-phase injection passage 9 through the powder supply nozzle 10 into the combustion gas flame.

A uniform slurry-like fine powder and combustion gas supply device will be described with reference to the schematic view of FIG. An ultrasonic vibrator 13 having an ultrasonic generator 12 is inserted into the slurry container 11 in the cylindrical shape. The frequency is changed according to the material, particle size and solvent of the fine powder and the optimum conditions are set, and the slurry fine powder is uniformly dispersed. The slurry fine powder is introduced into the slurry pump 14 and conveyed to the Y-shaped union 15. Adjust the flow rate with the number of rotations of the pump. The flow rate is confirmed with the slurry flow meter 16. On the other hand, the combustion gas stored in the combustion gas cylinder 17 is kept at a normal temperature through a water cooling gas cooling device 20 composed of a water jacket, adjusted with a fuel gas adjustment valve, and confirmed with a gas flow meter 18. These solid-liquid-gas three-phase mixtures are introduced into the three-phase injection passage 9.

When the theoretical oxygen equivalent is large with respect to the fuel, the combustion gas contains oxygen, and acetylene, methylene, ethylene, methane, ethane, butane, propane, or propylene gas introduced from the powder supply nozzle 10 on the inner surface of the tip tube 6. It reacts with the alcohol in the form of a slurry to raise the flame temperature, and the fine powder is heated to a high temperature. Therefore, by reducing the theoretical oxygen equivalent with respect to the fuel and flowing a large amount of acetylene, methylene, ethylene, methane, ethane, butane, propane, or propylene gas kept at room temperature on the inner surface of the tip tube 9 part, a fine powder The temperature is maintained at a low temperature, accelerated by the combustion flame coming from the combustion chamber, and collides with the base material to form a film.
The temperature of the conventional HVOF spraying method can be adjusted by water cooling, but the combustion flame is cooled from the inner surface of the spray gun cylinder, so the combustion flame is a gas and heat transfer is difficult. The temperature is difficult to decrease. On the other hand, by injecting a mixture of slurry-like powder and gas into the frame, the slurry-like powder is covered with acetylene or methylene cooled by the surrounding gas cooling device and cooled, so the temperature of the powder itself There is a difference that is suppressed from rising to the sublimation temperature and evaporation temperature.

The oxide αAl2O3 transforms to γAl2O3 at 1000 ° C or higher and dissolves at 2030 ° C. Anatase TiO2 transforms to rutile TiO2 at 700-800 ° C. SiO2 transforms at a low temperature of 573 ° C and dissolves at 1710 ° C.
Depending on the required properties of the coating, the fine powder is coated with the temperature kept below the transformation temperature and dissolution temperature.

The nitride AlN sublimates at 2450 ° C, and Si3N4 sublimes at 1900 ° C. BN sublimes at 3000 ℃. NbN decomposes at 2050 ° C. Depending on the required properties of the film, the fine powder is coated while being kept below the sublimation temperature.

The carbide αSiC transforms at 2100 ℃ and decomposes at 2830 ℃. Depending on the required properties of the coating, the fine powder is coated while maintaining the transformation temperature or lower.

The boride MoB evaporates at 2180 ° C. Depending on the required properties of the film, the fine powder is coated while being kept below the evaporation temperature.

Fluoride AlF3 undergoes sublimation decomposition at 1291 ° C, HfF4 undergoes sublimation decomposition at 968 ° C, and ZrF2 undergoes sublimation decomposition at 600 ° C. MgF2 evaporates at 2260 ° C, CaF2 evaporates at 2500 ° C, BaF2 ° C evaporates at 2260, GaF3 evaporates at 2270 ° C, YF3 evaporates at 2230 ° C, and ZnF2 evaporates at 1500 ° C. Depending on the required properties of the coating, the fine powder is coated while maintaining below the sublimation temperature and evaporation temperature.
The present invention will be described in detail with reference to examples.

A SUS304 specimen having a size of 50 mm × 50 mm × plate thickness 2 mm was used. Before forming the film, it is washed in advance and a grit blast treatment is performed as a roughening treatment. Alumina grit 80 mesh is used and sprayed onto the test specimen substrate at a pressure of about 0.5 Mpa. The surface roughness after blasting was Ra5 to 10 μm.

The powder and acetylene gas were stopped using the impact sintered coating gun shown in FIG. 1 and burned, and the test piece was heated from 50 ° C. to 150 ° C. for pre-heat treatment. This treatment removed moisture, water, and water vapor.

Mix with ethyl alcohol using αAl2O3 fine powder particle size 1μm to 3μm. For the αAl2O3 bulk volume 1, a volume 1.5 of ethyl alcohol is put into a slurry container 11 and subjected to ultrasonic waves to form a slurry. These mixtures are conveyed by a slurry pump 14 through a slurry conveying tube, mixed with acetylene maintained at room temperature through a Y-shaped union 15, and introduced into the three-phase injection passage 9. The distance from the tip tube tip 6 to the specimen base is kept at 150 mm, and the gun axis and specimen surface are held vertically. That is, the distance to the workpiece is 150 mm. The impact sintering coating conditions are summarized below.
[Conditions for impact-sintering coating]

Fuel kerosene: Pressure 0.8MPa, Flow rate 0.5L / min Oxygen gas: Pressure 1.0MPa, Flow rate 750L / min Compressed air: Pressure 0.5MPa, Flow rate 600L / min Powder supply rate: αAl2O3 + Ethyl alcohol: 450g / min Acetylene: Pressure 0.3 MPa, Flow rate 70 liter / min

The thickness of the impact-sintered coating film on the test piece substrate thus obtained was 50 μm, and the surface roughness was Ra1 to 2 μm. As a result of observing this film cross section with an optical microscope, it is a structure having a sintered layer containing some pores. As a result of examining this film with an X-ray diffractometer, αAl2O3 was detected.
This was coated in a combustion chamber without lowering the combustion temperature by reducing the oxygen equivalent to less than 1, and heating the slurry powder αAl2O3 to γAl2O3 by mixing with acetylene gas at room temperature and not heating above 1000 ° C. I understood that. The ionic conductivity of the αAl2O3 film was 70% of that of the αAl2O3 sintered body at 1000 ° C.

A SUS304 specimen consisting of a 30 mm × 100 mm cylinder was used. Before forming the film, it is washed in advance and a grit blast treatment is performed as a roughening treatment. Alumina grit 60 mesh is used and sprayed onto the specimen substrate at a pressure of about 0.5 Mpa. The surface roughness after blasting was Ra10-15 μm.

The powder and acetylene gas were stopped using the impact sintered coating gun shown in FIG. 1, and the test piece was heated from 50 ° C. to 150 ° C. for pre-heat treatment. This treatment removed moisture, water, and water vapor.

Mix Si3N4 powder with ethyl alcohol using 1µm to 2µm. A volume 2 of ethyl alcohol is put into a slurry container 11 with respect to 1 bulk capacity of Si3N4, and ultrasonic waves are applied to form a slurry. These mixtures are conveyed by the slurry pump 14 through the slurry conveying tube, mixed with acetylene through the Y-shaped union 15, and introduced into the three-phase injection passage 9. The distance from the tip of the tip tube 6 to the specimen base is maintained at 150 mm, and the gun axis and specimen surface are held vertically. The impact sintering coating conditions are summarized below.
[Shock-sintering coating conditions]

Fuel kerosene: Pressure 0.9MPa, Flow rate 0.45L / min Oxygen gas: Pressure 1.0MPa, Flow rate 600L / min Compressed air: Pressure 0.4MPa, Flow rate 500L / min Powder supply rate: Si3N4 + Ethyl alcohol: 500g / min Acetylene: Pressure 0.4 MPa, flow rate 60 liters / minute

The thickness of the sprayed coating on the specimen substrate thus obtained was 40 μm, and the surface roughness was Ra.
3-4 μm. The cross-sectional structure of the film was observed with an optical microscope. The result was a structure composed of a sintered layer having a porosity of 15 to 25%. As a result of examining this film with an X-ray diffractometer, Si3N4 was detected. This is because when the oxygen equivalent is reduced to less than 1 in the combustion chamber and the combustion temperature is lowered, and the slurry powder Si3N4 is mixed with acetylene gas at room temperature, the Si3N4 is maintained at a sublimation temperature of 1900 ° C or less and coated. I understood. Using the above Si3N4 film, a high temperature thermal shock test was performed by rapid cooling from 700 ° C. Good results were also obtained in repeated tests under severe thermal shock evaluation test conditions where large thermal stresses were generated at the interface. The thermal conductivity was 50% of the Si3N4 sintered body.

A SUS304 test piece of 20 mm × 150 mm × thickness 5 mm was used. Before forming the film, it is washed in advance and a grit blast treatment is performed as a roughening treatment. Alumina grit 60 mesh is used and sprayed onto the specimen substrate at a pressure of about 0.5 Mpa. The surface roughness after blasting was Ra10-15 μm.

The powder and acetylene gas were stopped using the impact sintered coating apparatus shown in FIG. 1, and the test piece was heated from 50 ° C. to 150 ° C. for pre-heat treatment. This treatment removed moisture, water, and water vapor.

Mix with methyl alcohol using αSiC particle size of 1μm to 3μm. For the αSiC bulk volume 1, a volume 1.5 of methyl alcohol is placed in a slurry container 11 and subjected to ultrasonic waves to form a slurry. These mixtures are conveyed by the slurry pump 14 through the slurry conveying tube, mixed with acetylene through the Y-shaped union 15, and introduced into the three-phase injection passage 9. The distance from the tip of the tip tube 6 to the specimen substrate is maintained at 130 mm, and the gun axis and specimen surface are held vertically. The impact sintering coating conditions are summarized below.

[Conditions for impact-sintering coating]
Fuel kerosene: Pressure 0.7 MPa, Flow rate 0.35 liter / min Oxygen gas: Pressure 0.8 MPa, Flow rate 600 liter / min Compressed air: Pressure 0.4 MPa, Flow rate 550 liter / min Powder supply rate: αSiC + Methyl alcohol: 300 g / min Acetylene: Pressure 0.3 MPa, Flow rate 80 l / min

The thickness of the impact-sintered coating film on the test piece substrate thus obtained was 60 μm, and the surface roughness was Ra2 to 3 μm. The cross-sectional structure of this film was observed with an optical microscope, and the result was a structure having a lamellar layer containing a few pores. As a result of examining this film with an X-ray diffractometer, αSiC was detected. This is because when the oxygen equivalent is reduced to less than 1 in the combustion chamber and the combustion temperature is lowered, and αSiC in the slurry powder is mixed with acetylene gas at room temperature, αSiC is maintained at 2100 ° C or less and decomposed. I understood. The emitter characteristics of the αSiC film were good, showing the same value as the sintered body αSiC.

A specimen of SUS304 having a diameter of 50 mm and a thickness of 10 mm was used. Before forming the film, it is washed in advance and a grit blast treatment is performed as a roughening treatment. Alumina grit 60 mesh is used and sprayed onto the specimen substrate at a pressure of about 0.5 Mpa. The surface roughness after blasting was Ra10-15 μm.

The powder and acetylene gas were stopped using the impact sintered coating gun shown in FIG. 1, and the test piece was heated from 50 ° C. to 150 ° C. for pre-heat treatment. This treatment removed moisture, water, and water vapor.

Mix with methyl alcohol using MoB particle size 1μm to 5μm. A volume 1 of methyl alcohol is placed in a container with respect to the bulk volume 1 of MoB, and ultrasonic waves are applied to form a slurry. These mixtures are conveyed by the slurry pump 14 through the slurry conveying tube, mixed with ethylene through the Y-shaped union 15 and introduced into the three-phase injection passage 9. The distance from the tip tube tip 6 to the specimen base is kept at 120 mm, and the gun axis and specimen surface are held vertically. In other words, the distance to the workpiece is 120 mm. The impact sintering coating conditions are summarized below.

[Shock-sintering coating conditions]
Fuel acetylene gas: Pressure 0.1 MPa, Flow rate 25 l / min Oxygen gas: Pressure 0.2 MPa, Flow rate 40 l / min Compressed air: Pressure 0.2 MPa, Flow rate 100 l / min Powder supply rate: MoB + Methyl alcohol: 50 g / min Ethylene : Pressure 0.35 MPa, Flow rate 70 l / min

The thickness of the impact sintered coating film thus obtained on the test piece base material was 110 μm, and the surface roughness was Ra 4 to 5 μm. The cross-sectional structure of this film was observed with an optical microscope, and the result was a structure having a lamellar layer containing a few pores. As a result of examining this film with an X-ray diffractometer, MoB was detected. This is because when the oxygen equivalent is reduced to less than 1 in the combustion chamber to lower the combustion temperature, and the slurry powder of MoB is mixed with ethylene gas at room temperature, the MoB is decomposed and kept at 2180 ° C or less. I understood. A wet ball-on-disk test was conducted at 100 ° C. in a lubricating fluid of engine oil 5W-30 using SUJ2 bearing alloy φ6 mm balls on the MoB coated disk. The seizure load was three times higher than the seizure test between SUJ2 bearing alloys.

A SUS304 specimen having a size of 50 mm × 50 mm × thickness 10 mm was used. Before forming the film, it is washed in advance and a grit blast treatment is performed as a roughening treatment. Alumina grit 120 mesh is used and sprayed onto the specimen substrate at a pressure of about 0.5 Mpa. The surface roughness after blasting was Ra5 to 10 μm.

The powder and acetylene gas were stopped using the impact sintered coating gun shown in FIG. 1, and the test piece was heated from 50 ° C. to 150 ° C. for pre-heat treatment. This treatment removed moisture, water, and water vapor.

Mix with methyl alcohol using YF3 particle size 1μm to 5μm. For YF3 bulk volume 1, place volume 1 of methyl alcohol in a container and apply ultrasonic waves to form a slurry. These mixtures are conveyed by the slurry pump 14 through the slurry conveying tube, mixed with ethane through the Y-shaped union 15 and introduced into the three-phase injection passage 9. The distance between the tip tube tip 6 and the test piece base is kept at 140 mm, and the gun axis and the test piece surface are held vertically. In other words, the distance to the workpiece is 140 mm. The impact sintering coating conditions are summarized below.

[Shock-sintering coating conditions]
Fuel kerosene: Pressure 0.7 MPa, Flow rate 0.25 l / min Oxygen gas: Pressure 0.8 MPa, Flow rate 200 l / min Compressed air: Pressure 0.4 MPa, Flow rate 400 l / min Powder supply rate: YF3 + Methyl alcohol: 200 g / min Ethane: Pressure 0.35 MPa, Flow rate 60 l / min

The thickness of the impact sintered coating film thus obtained on the test piece base material was 80 μm, and the surface roughness was Ra 4 to 5 μm. The cross-sectional structure of this film was observed with an optical microscope, and the result was a structure having a lamellar layer containing a few pores. Moreover, YF3 was detected as a result of examining this film with an X-ray diffractometer. It was found that YF3 was kept below 2230 ° C and was coated by lowering the combustion temperature by making the oxygen equivalent less than 1 in the combustion chamber and mixing the slurry powder YF3 with ethane gas at room temperature. . A plasma resistance test was performed on the test piece of the YF3 film. As a result of measuring the weight loss of the coating after a certain time by Ar sputtering using RF, the YF3 coating of the present method has a coating damage rate of 1/10 or less compared with the conventional alumina sprayed coating, which is excellent It showed plasma resistance.

Automotive industry: Abrasion resistance, seizure resistance Electronic equipment industry: Electrical insulation, plasma resistance, heat dissipation Medical: Antibacterial, tissue compatible Industrial equipment: Thermal insulation, oxidation resistance, corrosion resistance Chemical industry: Catalytic

1 Combustion chamber 2 Oxygen passage 3 Fuel passage 4 Burner 5 Gun nozzle 6 Tip tube 7 Compressed air passage 8 Compressed air injection ring 9 Three-phase injection passage 10 Powder supply nozzle 11 Slurry container 12 Ultrasonic generator 13 Ultrasonic vibrator 14 Slurry pump 15 Y-shaped union 16 Slurry flow meter 17 Combustion gas cylinder 18 Fuel gas adjustment valve 19 Gas flow meter 20 Gas cooling device

Claims (4)

In a shock-sinter coating device, a flame is generated by igniting a burner using a mixed gas of hydrocarbon and oxygen of fuel and burning in a combustion chamber. Lowering the temperature, installing a powder supply nozzle behind it, dissolving the powder using a fine powder and solvent coated from the nozzle and forming a slurry, and a solid-liquid-gas three-phase mixture consisting of combustion gas powder supply nozzle The temperature of the sprayed fine powder is decreased by increasing the amount of combustion gas held at room temperature, accelerating below the transformation temperature, sublimation temperature and evaporation temperature of the powder material, and instantaneously sintered by impact and coated. A shock-sintering coating method characterized by that. As a mixed gas of hydrocarbon and oxygen of the fuel according to claim 1, any one of kerosene / oxygen, propylene / oxygen, propane / oxygen, ethylene / oxygen, acetylene / oxygen, and natural gas / oxygen is used. In addition to the combination of hydrocarbon and oxygen, one type of hydrogen / oxygen, kerosene / air is used for combustion, combustion of hydrocarbons in a constant volume combustion chamber, and accompanying gas volume expansion, and An impact-sintering coating method characterized by increasing the frame speed by increasing the ratio of the cross-sectional area of the combustion chamber to the cross-sectional area, accelerating the coating powder, and instantaneously sintering the coating by impact. As a medium for making the coated fine powder of claim 1 into a slurry, one kind of ethyl alcohol, methyl alcohol, and kerosene is used and introduced into a container. The container is in contact with an ultrasonic generator so that the solvent and the powder are uniform. These slurry-like fine powders are charged into the flame of claim 2 and mixed as combustion gases such as acetylene, methylene, ethylene, propylene, butylene, methane, One or two of ethane, butane, propane, and propylene is used, and at that time, a solid-liquid-gas three-phase mixture of gas and slurry powder that is cooled by a gas cooling device and kept at room temperature is put into the frame. Thus, the impact-sintering coating method is characterized in that the coating powder is accelerated in a state where the temperature of the coating powder is lowered and is coated by instantaneous sintering. ΑAl2O3, anatase TiO2, βSiO2, sublimated AlN, Si3N4, BN, NbN, αSiC, AlF3, HfF4, ZrF2, MoB, MgF2, CaF2, BaF2, which evaporates below 2500 ° C An impact sintering coating method characterized by coating with GaF3, YF3, or ZnF2.

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