TWI468551B - Nozzle used in cold sprayer and cold sprayer device - Google Patents

Description

Cold sprayer nozzle and cold spray device

The present invention relates to a cold sprayer nozzle for greatly reducing the adhesion of a raw material powder of a nozzle during operation, in particular, a blockage caused by adhesion of aluminum powder, and a cold sprayer apparatus using the nozzle for a cold sprayer.

In the past, in the various types of metal members such as molds or rolling, automobile wheels, and gas turbine components, the wear resistance or corrosion resistance is improved, and the metal members are long-lived. A technique for forming a film of nickel, copper, aluminum, chromium or an alloy thereof on a metal member is known.

Among the methods for forming the film there are those using metal plating. However, this metal plating method cannot be applied to a large area and is prone to cracking.

Among other methods, there is a method of forming a film by spraying. As the spray, so-called reduced pressure plasma spray (LPPS), flame spray, high speed flame spray (HVOF), atmospheric plasma spray, and the like are included. However, when a film is formed by a spray method, there is a problem that it is difficult to form a dense film due to oxidation in the spray, and the conductivity and the thermal conductivity are low, and the adhesion rate is low, which is uneconomical. .

As a new technique for forming a film in place of this method, there has been a "cold spray method" in which a film of a raw material powder in a solid phase state is formed. In the cold spray method, the working gas having a melting point or a softening point lower than the raw material powder is a supersonic jet, and the transported raw material powder is supplied from the transport gas in the working gas, and then discharged from the tip end of the nozzle. The solid phase state thus collides with the substrate to form a film. In other words, a raw material powder such as a metal, an alloy, an intermetallic compound, or a ceramic is impinged on the surface of the substrate in a solid phase state at a supersonic speed to form a film.

Further, the cold spray technique will be described in detail as follows: A gas supply mechanism for a compressed gas cylinder in which nitrogen, helium, air, or the like is stored is divided into a working gas and a transport gas. Wherein, the high-pressure working gas is heated by a heater to After the temperature of the raw material powder is below the melting point, it is supplied to the spray gun chamber of the cold sprayer. On the other hand, the high-pressure conveying gas is introduced into the raw material powder supply mechanism, and the raw material powder is transferred into the spray gun chamber. The raw material powder conveyed by the carrier gas is supersonic jetted by the conical compression portion of the working gas passing through the nozzle, and is ejected from the nozzle outlet located at the tip end of the conical compression portion, and is formed by colliding with the solid phase of the substrate surface. Membrane.

The film formed by the cold atomizer is known to be dense, high-density, high in electrical conductivity and thermal conductivity, and low in oxidation or thermal deterioration, and is closely adhered to the film formed by the above-mentioned proposed spray. Good sex.

The biggest problem with such a cold sprayer is that the raw material powder adheres to the nozzle or is caused by the adhesion of the powder. Usually, the nozzle is made of stainless steel, tool steel, super-hard alloy, etc., but when a film is formed by a cold sprayer using nickel, copper, aluminum, stainless steel or the like as a raw material, the nozzles are particularly The expansion portion easily adheres to the raw material powder, which in turn causes the nozzle to clog. This is caused by friction between the raw material powder and the inner surface of the nozzle during operation, causing the temperature of the inner surface of the nozzle to rise and causing the raw material powder to condense on the inner surface of the nozzle. As a result, it becomes a cause of system failure, which also results in the need to change the nozzle from time to time. This is caused by the adhesion of the raw material powder to the nozzle or the nozzle clogging caused by it, which sometimes occurs several minutes after the start of the operation, and thus causes great obstacles in the practical application of the cold sprayer technology, particularly using aluminum powder as a raw material. In the case of the case, the condition in which the aluminum powder adheres to the respective portions of the nozzle is more pronounced, and the clogging of the nozzle is more remarkable.

A nozzle for a cold atomizer technique comprising polybenzimidazole at least in an expanded portion (enlarged portion) of a nozzle is disclosed in Patent Document 1 (Japanese Laid-Open Patent Publication No. 2004-298863), and it is claimed that the nozzle can be used by the nozzle It is possible to reduce the adhesion of metal powder to the nozzle or to block the nozzle.

Further, a nozzle for a cold atomizer is disclosed in the conical tip end portion connected to the nozzle inlet, and is connected to the tip end fine tip portion via a throat portion, as disclosed in Japanese Laid-Open Patent Publication No. 2005-95886. The short nozzle conical end expansion portion and the cylindrical parallel portion connected to the end expansion portion are provided with a loading and unloading mechanism and/or a powder input port in the parallel portion (Patent Patent No. 1). According to Patent Document 2, by designing the nozzle described above, it is possible to use a pipe of an inexpensive specification and to facilitate replacement of the parallel portion, and it is assumed that in a large-area construction of 0.5 m ² or more, if powder is deposited, Simply replacing only the cylindrical portion thereof can facilitate the maintenance of the nozzle when nozzle clogging occurs in the throat or the end expansion portion.

Further, in Patent Document 1, when polybenzimidazole is used as the nozzle material, the adhesion of the raw material powder to the nozzle or the nozzle clogging can be reduced to a certain limit. However, when aluminum powder is used as the raw material powder, the effect is not full. Further, since polybenzimidazole is a resin, it is easily consumed by the collision of the molten particles. Therefore, not only the nozzle life is short, but also the heat resistance is low, so that it cannot be used at a high temperature of 500 ° C or higher.

Further, in Patent Document 2, since the exchange of the nozzle member is facilitated, there is no intention to reduce the adhesion of the raw material powder to the nozzle or to reduce the clogging caused by the cause.

Therefore, as described above, the raw material powder adhering to the nozzle, particularly the adhesion of the aluminum powder or the nozzle sprayed by the nozzle, has a great problem in practical use and cannot be solved.

Therefore, an object of the present invention is to provide a nozzle for cold sprayer which is capable of greatly reducing the adhesion of a raw material powder in a nozzle for a cold sprayer during operation, in particular, adhesion of aluminum powder or adhesion of the powder, thereby achieving a long life. A nozzle for a cold sprayer and a cold sprayer device using the nozzle for the cold sprayer.

The present inventors have found that a part or the whole of the nozzle material for a cold sprayer, such as a fluororesin, a polyimide resin, or a composite resin thereof, can achieve the above object. The outline of the present invention will be described below.

The nozzle for a cold sprayer according to the present invention is characterized in that the nozzle for a cold sprayer according to the present invention is characterized in that it includes a tapered tapered portion at the tip end and is connected to the compression. a conical expansion portion having a wide front end portion, using a working gas having a temperature equal to or lower than a melting point of the raw material powder, causing the raw material powder to flow from the nozzle inlet of the compression portion, and ejecting the supersonic jet from the nozzle outlet at the tip end of the expansion portion, At least the inner peripheral wall surface of the expanded portion is formed of a resin of any of a fluororesin or a polyimide resin or a composite resin material thereof.

Therefore, the nozzle for a cold atomizer according to the present invention is preferably formed of a resin of any of a fluororesin, a polyimide resin, or the like.

Further, the nozzle for a cold sprayer according to the present invention is preferably formed by integrally molding a nozzle system for a cold sprayer.

The fluororesin used for the nozzle for cold sprayer according to the present invention is preferably a tetrafluoroethylene resin, a tetrafluoroethylene-perfluorovinyl ether copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, or a tetrafluoroethylene-ethylene copolymer. Any one of polyvinylidene fluoride, vinylidene fluoride resin or trifluoroethylene resin.

Further, the polyimine resin used for producing the nozzle for a cold sprayer according to the present invention is preferably used in a continuous use temperature of 300 ° C or higher in the atmosphere.

In the method for producing a nozzle for a cold atomizer according to the present invention, the method for producing a nozzle for a cold atomizer according to the present invention includes the at least one inner peripheral wall surface of the expanded portion of the nozzle for a cold atomizer described above, which is composed of a polyimide resin. A method for producing a nozzle for a cold sprayer, characterized in that a nozzle for a cold sprayer made of stainless steel is immersed in a precursor solution of the polyimide, and then preheated at a temperature of 80 ° C to 90 ° C 45 to 80 Minutes, and then final trimming heating to form a polyimine resin film forming process of the polyimide film on the inner peripheral surface of the nozzle of the cold sprayer as a process unit, repeating the above process unit several times, A polyimide film having a thickness of 200 μm to 800 μm is formed on the inner peripheral wall surface of the nozzle for the cold sprayer.

In the method for producing a nozzle for a cold atomizer according to the present invention, it is preferable that the final dressing heating is performed for each of 15 to 45 minutes in each of a temperature range of 100 ° C to 120 ° C, 130 ° C to 160 ° C, and 190 ° C to 210 ° C.

A method of manufacturing a nozzle for a cold sprayer according to the present invention, wherein the metal The nozzle for the cold atomizer is preferably made of any metal material such as stainless steel, copper or copper alloy.

In the method for producing a nozzle for a cold sprayer of the present invention, it is preferable to have a surface finishing process for smoothing and smoothing the surface of the polyimide film provided on the inner peripheral wall surface of the nozzle for the cold atomizer. .

Further, the cold atomizer device of the present invention is characterized in that it has at least the following mechanism: a raw material powder supply mechanism for supplying a raw material powder; a gas supply mechanism for supplying a working gas and a transport gas; A cold atomizer gun having a nozzle for a cold atomizer in which a raw material powder is sprayed at a supersonic velocity by a working gas having a melting point or lower of a raw material powder, and the nozzle for a cold atomizer described above is used as a nozzle for a cold atomizer.

[Effects of the Invention]

The nozzle for a cold atomizer according to the present invention and the cold atomizer device using the nozzle for the cold atomizer can greatly reduce the amount of the raw material powder during the operation, in particular, the adhesion of the aluminum powder to the inner peripheral wall surface of the nozzle for the cold atomizer or the adhesion of the powder. The cold sprayer that has occurred is blocked by the nozzle, and the life of the nozzle for the cold sprayer can be extended. Therefore, it is not necessary to frequently replace the nozzle for the cold sprayer.

The best mode for carrying out the invention will be described in detail below. Fig. 1 is a schematic cross-sectional view showing an embodiment of a nozzle for a cold sprayer of the present invention.

Form of nozzle for cold sprayer: The form of the nozzle for a cold sprayer will be described with reference to Fig. 1 . In Fig. 1, the nozzle 1 for a cold atomizer is a conical compressed portion 1b having a tip end having a tip end of the nozzle inlet 1a at the end portion, and a conical expansion portion 1c having a tip end portion extending from the front end of the nozzle outlet 1d. to make. The nozzle for a cold atomizer according to the present invention may have at least the above-described compressed portion 1b and the expanded portion 1c, and may have any other shape. For example, a narrow throat may be provided between the compression portion 1b and the expansion portion 1c, or a cylindrical parallel portion or the like may be provided on the nozzle outlet side of the expansion portion 1c. Further, in Fig. 1, arrows indicate the flow of the raw material powder.

In the present invention, at least the inner peripheral wall surface of the expanded portion 1c is formed of a resin of any of a fluororesin or a polyimide resin or a composite resin material (hereinafter referred to as "fluororesin or the like"). At least the inner peripheral wall surface as used herein means that an inorganic material such as a metal or a ceramic is used for the outer peripheral portion including the expanded portion, and only one of a fluororesin, a polyimide resin, or the like is used for the inner peripheral wall surface thereof. The meaning of the state of the composite resin lining is described. For example, the outer peripheral portion of the expanded portion is made of an inorganic material such as metal or ceramic, and then immersed in a solution of a polyimine resin precursor containing oxydiphenylamine and pyromellitic acid, and heated, and expanded. A method of forming a ruthenium-imided polyimide film layer on the inner peripheral wall of the portion may also be employed.

Since the expanded portion 1c is most likely to adhere to the raw material powder and is most likely to be blocked by the nozzle of the cold sprayer due to the adhesion of the raw material powder, the portion is formed of a fluorine branch or the like, thereby greatly reducing the adhesion of the raw material powder and the raw material. Blockage of the nozzle for the cold sprayer caused by the adhesion of the powder.

In the present invention, as described above, at least the expanded portion 1c is formed of a fluororesin or the like. However, the other portions of the compression portion 1b and the like may be formed of stainless steel or the like of the nozzle material for a cold sprayer which has been conventionally used. However, it is preferable that at least the inner peripheral wall surface of the entire other portion is formed of a fluororesin or the like. When the fluororesin or the like is present on the inner peripheral wall surface of the whole, the expansion portion 1c and the compressed portion 1b can significantly reduce the adhesion of the raw material powder and the clogging of the nozzle for the cold atomizer due to the adhesion of the raw material powder.

Therefore, it is preferred that the entire system of the expanded portion be composed of any of the resin materials of the fluororesin and the polyimide. If it is a single material, processing is easy and preferable. In addition, from the viewpoint of economy, the entire nozzle 1 for a cold sprayer is preferably formed into an integrally molded body by a fluororesin or the like.

The method of producing the single material such as the fluororesin such as the expanded portion 1c is not particularly limited, but is generally produced by hot compression molding using a mold or physical processing using a resin block.

Among them, the fluororesin is excellent in heat resistance, cold resistance, chemical resistance, and friction. Low, non-adhesive resin. The fluororesin used herein is not particularly limited, and examples thereof include tetrafluoroethylene resin (PTFE), tetrafluoroethylene-perfluorovinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and four. Fluorine-ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF) or trifluoroethylene resin (PCTFE), etc., but is preferably a tetrafluoroethylene resin.

Further, as for the polyimine resin, it is a general term for a synthetic resin having a quinone imine group. Among them, polyiminoimine resins, which are most widely known, are generally referred to as "all aromatic polyimines" which are produced by using oxydiphenylamine and pyromellitic acid. This polyimide resin is particularly excellent in heat resistance. Among them, those having a continuous use temperature of 300 ° C or higher in the atmosphere and 400 ° C or higher in an inert gas atmosphere are preferably selected. Further, since the polyimide resin is excellent in friction resistance and wear resistance, it is a high-performance material which combines the advantages of engineering plastics, metals, and ceramics.

Figure 2 is a schematic view of a cold sprayer device in accordance with the present invention. In Fig. 2, the gas supply mechanism is formed by a compressed gas high pressure cylinder 2, a working gas pipeline 3, a transport gas pipeline 4, and the like. The operating gas line 3 and the conveying gas line 4 are respectively provided with pressure regulators 5a and 5b, flow rate adjusting valves 6a and 6b, flow meters 7a and 7b, pressure gauges 8a and 8b, and the like, and are adjusted from the above. The pressure and flow rate of the working gas and the conveying gas of the compressed gas high pressure cylinder 2.

In the working gas line 3, the heater 10 heated by the power source 9 is disposed, and the working gas is heated to a temperature lower than the melting point or softening point of the raw material powder, and then introduced into the lance chamber 12 of the cold atomizer lance 11. A pressure gauge 13 and a thermometer 14 are also provided in the spray gun chamber 12 for controlling pressure and temperature.

On the other hand, the raw material supply mechanism is composed of the raw material powder supply mechanism 15 and the gauge 16 and the raw material powder supply line 17 attached thereto.

The carrier gas from the compressed gas high pressure cylinder 2 is introduced into the raw material powder supply device 15 through the transport gas line 4, and a specific amount of raw material powder measured by the meter 16 is supplied through the raw material powder supply line. 17 is transferred to the above-described lance chamber 12.

The raw material powder used herein is exemplified by a metal, an alloy, an intermetallic compound, etc., but specific examples thereof include a powder of aluminum, nickel, iron, silver, chromium or an alloy thereof, and aluminum powder is preferably used.

The raw material powder that has been transported into the lance chamber 12 by the transport gas is ejected from the tip end of the nozzle 1 by using the working gas as a supersonic jet, and collides with the base material 18 in a solid phase state or a solid-liquid coexistence state to form a film.

As described above, the nozzle 1 used herein includes a conical compression portion 1b having a tip end and a conical expansion portion 1c that communicates with the compression portion 1b and has a wide tip end portion, and at least the expansion portion 1c is made of a fluororesin or the like. Former.

For this reason, as described above, the raw material powder adheres to the inner wall portion of the nozzle for the cold atomizer during the operation of the cold atomizer, and the blockage of the nozzle for the cold atomizer caused by the adhesion of the raw material powder is greatly reduced.

In the manufacturing method of the nozzle for a cold atomizer according to the present invention, the nozzle for a cold atomizer according to the present invention is first made to contact the inner peripheral wall surface of the metal nozzle for the cold atomizer with the polyimide precursor solution. The so-called polyimine precursor solution, known as poly-proline, is an organic tetracarboxylic dianhydride and an aromatic diamine in N-methyl-2-pyrrolidone, N, N- In a solvent such as dimethylacetamide, N,N-dimethylformamide, dimethylhydrazine or hexamethylsulfonamide, it is polycondensed at a temperature of 0 ° C to 80 ° C for 1 hour to 48 hours. The polyglycolate solution was obtained in the varnish state at the left and right time. At this time, the solid content of the polyamic acid in the varnish is preferably in the range of 10% by weight to 25% by weight. If the solid content of the poly-proline is less than 10% by weight, the polyimide film becomes thinner and the productivity is lowered, which is not preferable. On the other hand, when the solid content of the polyamic acid exceeds 25% by weight, the film thickness of the polyamic acid film becomes larger than the average value, and the deviation of the thickness of the formed polyimide film becomes larger, so that Not good.

Here, "the inner peripheral wall surface of the nozzle for the cold atomizer made of metal is brought into contact with the polyimide precursor solution", and the inner peripheral wall surface of the nozzle for the cold atomizer is brought into contact with the polyimide precursor solution. As long as the inner peripheral wall surface of the nozzle for the cold sprayer is brought into contact with the polyimide precursor solution, any method is employed. can. The most common method is to use a method in which a polyimide precursor solution is passed through a nozzle of a metal cold sprayer, and a metal cold sprayer is immersed in a polyimide precursor solution to make a poly Any of the methods of filling the amine precursor solution into the interior of the nozzle.

As described above, the polyimide film layer is formed on the inner peripheral wall surface of the nozzle for the cold atomizer. The formation operation of the polyimide film is set as a process unit. Here, the preheating conditions are 80 ° C to 90 ° C × 45 to 80 minutes, and if the conditions are removed, the surface roughness of the formed polyimide film is increased, which is not preferable.

Then, if necessary, the process unit can be repeated a plurality of times to form a polyimide film having a thickness of 200 μm to 800 μm on the inner peripheral wall surface of the nozzle for the cold sprayer. When the thickness of the polyimide film layer is less than 200 μm, the durability is deteriorated, which makes it difficult to surface-treat the subsequent polyimide layer of the polyimide. On the other hand, when the thickness of the polyimine resin layer exceeds 800 μm and the thickness is more than the above, the durability required as a nozzle for a cold atomizer is not improved, and it is not preferable because the cost is increased.

In the method for producing a nozzle for a cold sprayer according to the present invention, the trimming heating performed in a state in which the preheating treatment is completed is not particularly limited as long as the polyphosphonium amide is imidized. Generally, it is heated at a temperature in the range of 250 ° C to 500 ° C. However, as the trimming heat treatment, it is preferred to apply a three-stage heat treatment. The first stage of heating is heated at 100 ° C ~ 120 ° C × 15 ~ 45 minutes. The second stage of heating is heated at 130 ° C ~ 150 ° C × 15 ~ 45 minutes. The third stage of heating is heated at 190 ° C ~ 210 ° C × 15 ~ 45 minutes. With such a stepwise heating, the hydrazine imidization reaction of the polyimine precursor solution (polyproline) can be carried out slowly, so that the polyimide layer formed on the inner peripheral wall surface of the nozzle of the cold atomizer is slowly The surface roughness becomes smooth.

As described above, after the polyimide film is formed on the inner peripheral wall surface of the nozzle for a cold sprayer, if the surface of the polyimide film layer does not have an appropriate surface state, it is preferable to provide the polymer after the event. The surface of the yttrium imide resin layer becomes a smooth and smooth surface finishing process. The surface finishing treatment uses resin etching, stone grinding (honing) physical processing methods such as processing and polishing.

In the method for producing a nozzle for a cold sprayer according to the present invention, the cold spray nozzle made of the metal is preferably made of any metal material such as stainless steel, copper or copper alloy. Stainless steel has excellent properties as a heat-resistant material, and is preferably a material that flows inside as a high-temperature cold sprayer. Further, copper or a copper alloy is excellent in thermal conductivity, and is preferably a metal material excellent in heat dissipation. The copper alloy referred to herein is a copper-nickel alloy, a copper-silver alloy, a copper-nickel-zinc alloy, or the like.

A cold atomizer device according to the present invention includes at least the following means: a raw material powder supply mechanism for supplying a raw material powder; a gas supply mechanism for supplying a working gas and a transport gas; and A cold spray gun for a nozzle for a cold sprayer which is sprayed at a supersonic speed by a working gas below the melting point of the raw material powder. Therefore, the cold atomizer device is characterized in that the nozzle for a cold sprayer described above is used as a nozzle for a cold sprayer. The cold atomizer device configured as described above can greatly reduce the adhesion of the raw material powder (especially aluminum powder) during the operation to the inner peripheral wall surface of the nozzle of the cold sprayer or the nozzle of the cold sprayer which is caused by the adhesion of the powder, and can A cold sprayer device that achieves a long life.

Hereinafter, the present invention will be specifically described by way of examples.

[Comparative Example 1]

In Comparative Example 1, a nozzle for a cold atomizer shown in Fig. 1 was obtained by using a fluororesin (tetrafluoroethylene resin) as an integrally molded product. Using the cold sprayer nozzle, the cold sprayer operation was performed by the cold sprayer apparatus shown in FIG. The operating conditions and equipment used for the cold sprayer are listed in Table 1 below.

As a result, after the operation for 30 minutes, the raw material powder of the inner wall portion of the nozzle for the cold atomizer did not adhere, and the nozzle for the cold atomizer was not clogged. The results are shown in Table 2 in the manner of comparison with the examples.

[Example 1]

In the present embodiment, a nozzle for a cold atomizer shown in Fig. 1 was obtained by using a wholly aromatic polyimide resin (Sumitomo Chemical Co., Ltd., using MELDIN (registered trademark)) as an integrally molded product. Using the cold sprayer nozzle, the cold sprayer operation was performed by the cold sprayer apparatus shown in FIG. The others were the same as in Comparative Example 1.

[Embodiment 2]

This embodiment is based on the surface of the nozzle for a stainless steel refrigerating sprayer shown in Fig. 1, to form a polyimide film, and to manufacture a polyimide-coated nozzle. Hereinafter, the manufacturing order will be described.

A stirrer is placed in the container, and a nitrogen gas introduction pipe and a nitrogen gas outflow pipe are provided in the vessel. Next, 40.02 g (0.13 mol) of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride was added to the vessel. Next, 300 g of a mixed solvent of N-methyl-2-pyrrolidone and diethylene glycol monomethyl ether in a ratio of 1:1 (by weight) was added, and the mixture was mixed under a nitrogen purge. In the above, under a nitrogen gas stream, for the bis(3-aminopropyl)polydimethyl decane having an average molecular weight of 790, 11.20 g (0.014 mol), 150 g of the above mixed solvent was added dropwise over 30 minutes, and thoroughly mixed. . Reveal, At the end of the mixing, while using an ice bath at 0 ° C, 44.38 g (0.13 mol) of 4,4'-1,3-phenylene bis(1-methyl amide) was added in 5 portions under a nitrogen stream. Ethyl)aniline was further stirred while maintaining the temperature of the solution at 30 ° C or lower for 5 hours to obtain a polyimide precursor solution. In addition, the preparation of the polyimide precursor solution is described in Patent Document 3 (Japanese Laid-Open Patent Publication No. Hei No. Hei-5-79224).

Subsequently, a nozzle for a cold sprayer made of stainless steel is immersed in the polyimide precursor solution, and the inner peripheral wall surface of the nozzle for the cold sprayer is brought into contact with the polyimide precursor solution, and heated at 80 ° C for 1 hour. Each of them was heated at 100 ° C, 150 ° C, and 200 ° C for 30 minutes to form a yellowish transparent polyimide resin layer on the surface of the nozzle for a cold sprayer made of stainless steel. The above operation was repeated several times to produce a nozzle coated with a polyimide film having a polyimide layer having a thickness of 500 μm. The cold sprayer operation was carried out using the cold sprayer apparatus shown in Fig. 2 using the nozzle coated with this polyimide film. The others were the same as in Comparative Example 1.

Further, the glass transition temperature (value measured by TMA) of the polyimide film forming the polyimide coating layer is 180 ° C, and the 5% weight loss temperature (measured by TGA) under nitrogen is 490 ° C, heat The decomposition temperature was 500 ° C, and the imidization ratio measured by infrared spectroscopy was 95% or more.

[Comparative Example 2]

The nozzle for the cold sprayer shown in Fig. 1 is integrally molded using conventional stainless steel. Using the cold sprayer nozzle, a cold spray operation was performed using the cold sprayer apparatus shown in Fig. 2. The operating conditions and the device used were the same as in Comparative Example 1.

As a result, after 4 to 5 minutes of operation, the raw material powder began to adhere to the inner wall surface of the expanded portion of the nozzle for the cold sprayer, and after 5 to 6 minutes, the cold sprayer was blocked by the nozzle. Therefore, the spraying efficiency cannot be measured.

1) Fluoro Resin: One molded product of tetrafluoroethylene resin 2) PI: One-piece molded product of wholly aromatic polyimine resin 3) PI coating: nozzle coated with yttrium imide resin layer 4) Stainless steel: Stainless steel one-piece molded product

[Comparison of Examples and Comparative Examples]

As is fully understood from Table 2, there is no difference between the examples and the comparative examples from the viewpoint of nozzle wear. The raw material powder heated to a working gas temperature of 300 to 350 ° C during cold spraying is almost in a solid state. When the raw material particles collide with the inner wall portion of the nozzle for the cold atomizer, the difference in the constituent materials of the nozzle for the cold atomizer is clearly displayed. In the comparative example, a nozzle for a cold sprayer was made of stainless steel. This stainless steel can be said to be a hard material which does not show significant softening at a temperature of 300 to 350 °C. On the other hand, at least the inner peripheral wall surface of the nozzle for a cold atomizer used in the examples was a fluororesin or a polyimide resin, which was softer than stainless steel. In other words, when the nozzle for a cold sprayer is used in the temperature range described herein, a nozzle for a cold sprayer is produced by using a soft-based material of a heat-resistant resin without using a hard material of a metal type, and it is known that the nozzle has little wear.

Further, in view of the state of nozzle clogging, it is clear that the embodiment is superior to the comparative example. When the working gas temperature is in the range of 300 to 350 ° C, if the raw material powder is in a solid state, the raw material particles colliding with the inner wall portion of the nozzle for the cold atomizer vary depending on the degree of plastic deformation of the particle shape of the nozzle of the cold atomizer. Comparison In the case of using a nozzle for a cold atomizer formed of stainless steel in the example, the collision particles of the inner peripheral wall are greatly deformed, and the adhesion phenomenon is remarkably exhibited, and it is blocked in 5 to 6 minutes, and the cold spray operation cannot be performed. On the other hand, in the embodiment, at least the inner wall portion of the nozzle for the cold atomizer is formed of any soft resin material such as fluororesin, so that plastic deformation of the raw material particles colliding with the inner wall surface is caused, and adhesion is less likely to occur. As a result, in the case of the example, the cold atomizer was continuously operated for 30 minutes, and no nozzle clogging occurred at all.

[Industry use possibility]

According to the nozzle for a cold atomizer according to the present invention and the cold atomizer device using the nozzle for the cold atomizer, the raw material powder during the operation of the cold atomizer, in particular, the adhesion of the aluminum powder to the nozzle of the cold atomizer and the nozzle clogging caused by the adhesion of the raw material powder Can be greatly reduced. As a result, the life of the nozzle for a cold atomizer can be extended. Thus, there is no need to change the nozzle frequently. Therefore, the present invention is extremely useful for the practical use of cold sprayer technology.

1‧‧‧Nozzles for cold sprayers

1a‧‧‧nozzle entrance

1b‧‧‧Conical compression

1c‧‧‧Conical expansion

1d‧‧‧nozzle exit

2‧‧‧Compressed gas high pressure cylinder

3‧‧‧Working gas pipeline

4‧‧‧Transporting gas pipeline

5a‧‧‧Pressure regulator

5b‧‧‧Pressure regulator

6a‧‧‧Flow adjustment valve

6b‧‧‧Flow adjustment valve

7a‧‧‧Flow meter

7b‧‧‧Flowmeter

8a‧‧‧ pressure gauge

8b‧‧‧ pressure gauge

9‧‧‧Power supply

10‧‧‧heater

11‧‧‧Cool sprayer spray gun

12‧‧‧gun chamber

13‧‧‧ Pressure gauge

14‧‧‧ thermometer

15‧‧‧Material powder supply device

16‧‧‧meter

17‧‧‧Material powder supply line

18‧‧‧Substrate

Fig. 1 is a schematic cross-sectional view showing an embodiment of a nozzle for a cold atomizer according to the present invention.

Figure 2 is a schematic view of a cold sprayer device of the present invention. Further, the arrows shown in the drawings indicate the flow direction of the raw material powder.

1‧‧‧Nozzles for cold sprayers

1a‧‧‧nozzle entrance

1b‧‧‧Conical compression

1c‧‧‧Conical expansion

1d‧‧‧nozzle exit

Claims (5)

A nozzle for a cold sprayer, comprising: a tapered conical compression portion having a tip end; and a conical expansion portion having a wide end before communicating with the compression portion, wherein the raw material powder is made of a working gas having a temperature lower than a melting point of the raw material powder The nozzle inlet of the compression portion flows in, and the nozzle outlet at the tip end of the expansion portion is ejected by a supersonic jet, wherein at least the inner peripheral wall surface of the expansion portion is formed of a polyimide resin. A nozzle for a cold sprayer according to the first aspect of the invention, wherein the whole is formed of a polyimide resin. The nozzle for a cold sprayer according to the second aspect of the patent application, wherein the cold sprayer is integrally formed by a nozzle. The nozzle for a cold sprayer according to the first aspect of the invention, wherein the polyimine is continuously used in the atmosphere at a temperature of 300 ° C or more. A cold atomizer device comprising: a raw material supply mechanism for supplying a raw material powder; a gas supply mechanism for supplying a working gas and a transport gas; and a working gas having a temperature equal to or lower than a melting point of the raw material powder, and the raw material powder is super A cold spray gun for a nozzle for a cold sprayer to be sprayed by a sonic jet, wherein a nozzle for a cold sprayer as in the first aspect of the patent application is used as the nozzle.