JP3357610B2 - Micro-nitrided molding and molding method thereof, and ceramic coating molding and molding method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article by so-called micro-nitridation for forming a fine nitrogen compound layer on the surface of a metal material, a molding method thereof, and a method utilizing, for example, the excellent mechanical properties of ceramics. Also, the present invention relates to a ceramic coating molded product obtained by using a nitride, an oxide, or a boron compound as a material for the purpose of protecting the surface of a product to be treated such as wear resistance, corrosion resistance, heat resistance, or decoration, or lubrication, and a molding method thereof. , More specifically, iron-based metals such as steel and cast iron or non-ferrous metals such as aluminum and brass,
Alternatively, a sprayed powder is sprayed with a reactive spray gas, for example, compressed nitrogen gas, on the surface of a metal product made of a powder alloy such as a cemented carbide, a ceramic alloy, or a cermet, or a processed product made of a ceramic or a mixture thereof. And
Forming a nitride formed by forming a nitride layer of a compound layer generated by the reaction of the spray powder and the reactive spray gas on the surface of the article to be treated, and a method of forming the nitride, or ceramic coating or, particularly, aluminum or As a general term in a broad sense including the nitriding treatment in the present invention, in which the nitriding treatment at room temperature is put to practical use in the nitriding treatment of an aluminum alloy or the like, the inorganic compound and the intermetallic compound including the nitrided layer are formed or coated on the surface of the article to be treated. The present invention relates to a ceramic coating molded product and a molding method thereof.

[0002]

2. Description of the Related Art Conventional nitriding treatment requires a temperature of about 550.degree.
Gas nitriding and oxynitriding using ammonia gas for ~ 100 hours, salt bath nitriding performed at about 580 ° C in a mixture bath of cyanide and cyanate, reduced pressure with N2 introduced, ionized under glow discharge There is ion nitridation for infiltrating and diffusing nitrogen into steel, and gas nitrocarburizing, sulphonitriding and the like are also performed.

[0003] The ceramic coating method includes:
Examples include plasma spraying, PVD (physical vapor deposition), and CVD (chemical vapor deposition).

[0004] In plasma spraying, a sprayed powder is fed into an ultra-high-temperature, high-speed jet formed by injecting an inert gas such as argon plasmatized by an arc from a thin nozzle to melt the sprayed powder. A method of forming a film on the surface of a base material by accelerating it while applying it to the formation of high-density, high-strength films of metal materials such as molybdenum and nickel-based alloys, and thin films of high-melting materials such as ceramics. .

[0005] The PVD method is a method of heating a solid at a high temperature or forcibly evaporating and condensing it without forming a chemical reaction to form a thin film, and includes a vacuum deposition method, an ion plating method, a sputtering method and the like.

[0006] The vacuum evaporation method is a method in which a substance is heated and evaporated in a vacuum to form a thin film by depositing the substance in a layer on the surface of a product to be treated. It has features such as obtaining a thin film.

The ion plating method is a method of forming a thin film by ionizing or exciting evaporated atoms by using plasma generated by applying an electric field.

In the sputtering method, ionized plasma is generated at a relatively low degree of vacuum, and ionized argon is accelerated to collide with a target (a solid raw material serving as a target by collision of accelerated particles) to strike out target atoms. This is a method of coating on the surface of the product to be treated.

[0009] The CVD method is a method of forming a thin film by a chemical reaction of a metal vapor or a volatile compound vapor in a gas phase, and an electric furnace method, a chemical flame method,
There are an electron beam method, a laser method, a plasma method, and the like.

[0010]

In the conventional nitriding treatment including gas nitriding, the treatment temperature is generally extremely high, the treatment time is long, and the equipment cost is necessarily high. There were problems such as pollution problems.

In particular, nitriding of aluminum, aluminum alloy, and the like is difficult to cause nitriding because an oxide film is formed on the surface. Although nitriding in vacuum is possible,
Productivity and cost are not suitable for practical use. In the case of stainless steel, the treatment by ion nitriding has the same problems as aluminum and the like in terms of cost, in addition to the reduction in strength and the generation of pollution due to pickling.

The conventional ceramic coating method has the following problems.

For example, the vacuum vapor deposition method has a problem in that equipment costs for a vacuum tank, a rotary pump for evacuating the tank, and an oil diffusion pump are high.

Further, other PVD methods and various CVD methods also require expensive equipment and have a problem of high cost.

The sputtering method has a problem that even if the deposition rate of the film is high, it is as low as several hundred Å / min, which is not suitable for forming a thick film.

The present invention has been developed in order to solve the above-mentioned problems. The object and the effect of the present invention are to inject a sprayed powder onto a surface of an article to be treated with a reactive spray gas, Forming a compound layer generated by the reaction between the powder and the reactive injection gas on the surface of the article to be treated, and protecting the surface of the article to be treated from wear, corrosion and heat resistance by a thin film forming method using inexpensive equipment. It is another object of the present invention to provide a ceramic-coated molded product and a molding method capable of improving a lubricating effect and enhancing aesthetic product value by decoration. In detail, it is possible to perform the same processing as the conventional ceramic coating method in a short time by blast processing of inexpensive machinery and equipment, and to protect the surface of the product to be treated such as wear resistance, corrosion resistance and heat resistance, or to lubricate Ceramic coating that can improve the function, is aesthetically pleasing in decoration, and can increase the commercial value at a lower cost than the conventional ceramic coating method, or a completely new equipment at room temperature with no pollution caused by simple equipment It is an object of the present invention to provide a fine nitride by various means.

[0017]

To achieve the above object, according to the Invention The fine nitride molded product of the present invention, the treated finished product and the injection powder as metallic product having a nitrogen reactive component, or a metal formed
Treated formed article and the injection powder consisting of a mixture of goods and ceramics, or consists of injection powder having a treated-products and nitrogen-reactive component consisting of ceramic, pre-Symbol treated formed article surface or, in the treated finished products surface the formed film, the nitrogen
Reaction components are produced by chemical reaction in a nitrogen gas atmosphere.
Is formed by diffusing and penetrating the nitride. As a forming method, using a metal product having a nitrogen reaction component or a product to be processed consisting of a mixture of the metal product and ceramics, or a product to be processed made of ceramics and an injection powder having a nitrogen reaction component, and blasting A mixed fluid comprising the sprayed powder and nitrogen gas is sprayed onto the surface of the product to be treated, and a nitrogen compound produced by a chemical reaction between the product to be treated and / or the sprayed powder having the nitrogen reaction component and the nitrogen gas is removed. It is characterized in that a nitrided layer is generated by diffusing and penetrating into the surface of the article to be treated.

The ceramic-coated molded article of the present invention is characterized in that various compounds such as oxides, carbides, nitrides and other intermetallic compounds generated by the chemical reaction of the powder and the reactive gas are converted into metal products or It is characterized in that it is formed by diffusion infiltration or coating on the surface of an article to be treated made of ceramics or a mixture thereof.

In the method for molding a molded article, a nitrogen gas is used as a compressed fluid as an injection medium in a micro-nitrided molded article, and a gas containing oxygen or carbon in addition to nitrogen in a ceramic-coated molded article. That is, by blast treatment using a reactive injection gas of one or several types of mixed gas having high reactivity, such as oxidizing, carburizing, nitriding, etc., preferably a spherical average particle diameter is 200 to 20.
μm, preferably from 100 μm to 20 μm, and nitrogen alone as a reactive injection gas, or a mixed fluid comprising the reactive injection gas, treated with a metal product or ceramic or a mixture thereof under the above conditions. Injection speed 80m / sec or more or injection pressure 0.3MPa on the surface of the product
The method is characterized in that the nitrided layer or the compound layer is formed by spraying and diffusing and penetrating or coating the elements in the composition of the article to be treated or the sprayed powder and the reactive jetting gas.

Here, the abrasive is not limited to a metal or a synthetic resin, but is used for any grinding or surface cleaning. Means for injecting a solid-gas two-phase flow of gas and gas include so-called shot peening.

Incidentally, the average particle diameter is represented by an average of the average diameter of the largest particle and the average diameter of the 30th particle from the largest particle.

For example, a fine powder having an average particle diameter of 80 μm has an average diameter of the largest particle of 171 μm or less, an average diameter of the 30th particle from the largest particle is 120 μm or less, and an average of 87.5 to 73.5 μm. (JlSR6001).

When the blasting process injects the injection powder at a high injection speed onto the surface of the article to be processed, the energy-invariant law is obtained by a change in speed before and after the collision of the injection powder with the surface of the article to be processed. When considered, heat energy is generated. Since this energy conversion is performed only at the deformed portion where the injected powder collides, the temperature is locally increased near the surfaces of the injected powder, the reactive injected gas, and the product to be processed.

Further, since the temperature rise is proportional to the velocity of the injected powder before collision, if the injection velocity of the injected powder is increased,
The temperature of the propellant powder, the reactive propellant gas and the surface of the article to be treated can be increased. At this time, since the sprayed powder is heated on the surface of the product to be treated, the elements in the sprayed powder and the reactive spray gas cause a chemical reaction to form a compound, and furthermore, the resulting compound is heated to a temperature higher than the temperature. Thus, it is considered that the activated product is activated and adsorbed on the surface of the article to be processed, diffused and penetrated or coated, and a nitride layer or a film of another compound is formed on the surface of the article to be processed.

At the same time, effects such as surface processing heat treatment as shot peening can be obtained. Therefore, unlike the conventional ceramic coating, the micronitride and ceramic coating molded article and the molding method of the present invention are based on the temperature rise of the injected powder when the injected powder is caused to collide with the product to be processed by blasting. The present invention relates to a completely novel means for forming each compound layer by diffusing and penetrating or coating a compound produced by a chemical reaction between a sprayed powder and a sprayed gas on a surface of an article to be treated.

In order to describe in more detail, taking a vacuum deposition method as a conventional ceramic coating method as an example, a thin film material is heated and evaporated under a high vacuum, usually at a pressure lower than 1 × 10 ⁻⁶ Torr, and the evaporation is performed. The particles are deposited on the surface of the workpiece to form a thin film. In particular, in order to form a thin film of oxide, nitride or carbide, the metal constituting the compound is evaporated as a thin film material, and the thin film is formed in a reactive atmosphere gas such as oxygen, nitrogen, ammonia, or methane. The formation of adduct particles between reactants and their thermal decomposition into oxides, nitrides or carbides, or the nucleation and growth of oxides, nitrides or carbides, or the formation of metal particles and their oxidation, nitridation or A thin film of the compound can be deposited by any reaction process of carbonization. For example, atmospheric pressure 1
Under 0 ^-5 Torr to 10 ^-4 Torr, Al,
When oxygen is used as an atmosphere gas, a ceramic thin film Al2O3 is formed at 400 to 500.degree. C., and when ammonia is used as an atmosphere gas, polycrystalline AlN is formed at 300.degree.

In the case of carburizing, the deposition of particles on the surface of a product to be treated is simply performed by removing CO gas from the surface of an iron-based metal product simply by an external force, heating or other physical method. Although the product Fe and CO cannot react only by physical attachment as much as possible, the CO gas is activated and adsorbed on the Fe surface when heat or other energy is applied for a certain amount or more. This activated adsorption
CO gas thermally dissociates into carbon dioxide and carbon. It is believed that the carbon produced by this reaction diffuses into the Fe lattice and causes carburization. In addition to carbon diffusion, surface diffusion (diffusion along the surface) and grain boundary diffusion (diffusion that progresses along the grain boundaries), generally in the form of one element diffusing in a metal And lattice diffusion (diffusion that proceeds while sewing in a crystal lattice). Lattice diffusion is only when both the element and the metal form a solid solution. When neither the element nor the metal forms a solid solution, only surface diffusion or grain boundary diffusion is performed.

In view of the above-mentioned phenomena of vacuum deposition and carburization, it is considered that the ceramic coating of the present invention forms a compound layer on the article to be treated in the following process.

For example, an injection powder is sprayed onto the surface of the article to be processed at an injection speed of 80 m / sec or more or an injection pressure of 0.3 MPa or more, and collides with the surface of the article to be processed. Decrease. Considering the law of energy invariance, thermal energy is generated due to internal friction due to deformation of the collision part with the processed product at the time of collision, and the injected powder is heated on the surface of the processed product by this thermal energy In addition, the injected powder and the injected gas are simultaneously activated and reacted, and furthermore, the compound generated by the reaction is activated and adsorbed on the product to be treated and diffused or penetrated or coated, thereby forming a compound layer. Conceivable.

In the case of compressed nitrogen gas, the surface temperature of the article to be treated becomes higher than the nitrogen permeation diffusion temperature, and reacts with the nitrogen gas.
It is believed that nitriding occurs.

The purpose of the present invention is to activate and adsorb the compound on the surface of the product to be treated by utilizing the temperature rise of the powder to be sprayed. In order to be heated, the shot must be not a heavy shot but a powdery shot having a particle size of 200 μm to 20 μm, that is, a sprayed powder, and is preferably 100 μm or less to improve the film thickness and adhesion. Further, in consideration of efficient conversion to the thermal energy at the injection speed, the injection pressure is preferably 0.3 MPa or more.

Applying heat to the propellant gas and / or the article to be treated is more effective in increasing the reactivity.

In the case of micro-nitriding, nitrogen gas is required, but it is sufficient if either the product to be treated or the powder to be sprayed has a nitrogen reaction component. The nitride is simultaneously formed on the film formed on the surface of the product to be processed by the sprayed powder. In the method of the present invention, at least one of the reactions is performed to form or coat a nitrided layer.

For example, when injecting a mixed fluid using compressed nitrogen gas, the product to be treated is Ti, V, A which is a nitrogen reaction component.
l, Cr, etc., when the sprayed powder is the same metal, a nitride layer of TiN, VN, AlN, CrN, etc. is formed on the surface of the product to be treated by diffusion and infiltration. Nitride will also form in the surface coating covered by the body. When the surface of the article to be treated is the same as above and there is no nitrogen reaction component such as a case where the sprayed powder is ceramics, nitride is generated only on the surface of the article to be treated. If there is a nitrogen reaction component in both the processed product and the sprayed powder, nitrides are generated on the surface of the processed product and the coating.

Also in this case, a coating film can be formed by the sprayed powder. In addition, when the product to be treated is a metal material containing Ti, V, Al, Cr, etc., or a mixture of this and ceramics, if the injected powder is the same as the product to be treated, both the product to be treated and the coating are nitrided. If a product to be treated is ceramic and the powder mixture is the above-mentioned mixture, nitride is generated only in the coating.

That is, if only the product to be treated has a nitrogen reaction component, a nitride is formed on the surface of the product to be treated. If there is no nitrogen reaction component in both the product to be treated and the injection powder, nitriding is not performed, and When there is a nitrogen reactive component only in the body, nitride is generated only in the formed film.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION The blasting apparatus used in the first embodiment is a gravity type blasting apparatus, but a suction type siphon type or suction type as long as it is an air type in which an abrasive is blown using the injection energy of compressed gas. Alternatively, another blasting device such as a direct pressure type may be used.

In the direct pressure type, the abrasive and the dust after being sprayed are separated in a powder recovery tank as the abrasive here, and the dust is sent to a dust collector provided with an exhaust fan through a duct, and the abrasive is removed. It falls below the collection tank and accumulates in the lower part of the collection tank. A pressurized tank is provided at the lower part of the recovery tank via a dump valve. When the pressurized tank runs out of abrasive, the dump valve lowers and the powdered abrasive in the recovery tank enters the pressurized tank. When the powder enters the pressurized tank, the compressed gas enters the tank, and at the same time, the dump valve closes, the pressure in the pressurized tank increases, and the powder is pushed out from the supply port at the bottom of the tank. A compressed gas as a reactive injection gas is separately introduced into the supply port, the powder is conveyed to a nozzle by a hose, and the powder is injected at a high speed from the nozzle tip together with the gas.

In brief, the suction type blasting device will be briefly described. Here, when a compressed gas is injected into a suction injection nozzle from a hose communicating with a compressed gas supply source as a reactive injection gas, a negative pressure is generated in the nozzle. Becomes
Due to this negative pressure, the powder in the tank is sucked into the nozzle via the abrasive hose and is ejected from the nozzle tip.

In FIG. 1, a gravity type blasting device 30
Is provided with a nozzle 32 for injecting an abrasive 36 such as a shot into a cabinet 31 having an entrance 35 for taking in and out the product W to be processed, and a pipe 44 is connected to the nozzle 32. It communicates with a compressor not shown, from which compressed gas is supplied. A hopper 38 is provided at a lower portion of the cabinet 31, and a lowermost end of the hopper 38 communicates with an upper side surface of a collection tank 33 installed above the cabinet 31 via a conduit 43, and a lower end of the collection tank 33 connects a pipe 41. The nozzle 32 is communicated with the nozzle 32 via the nozzle. The abrasive in the collection tank 33 falls from the collection tank 33 under gravity or a predetermined pressure and is injected into the cabinet 31 together with the compressed gas supplied to the nozzle 32 through the pipe 44.

In the recovery tank 33, an abrasive 36 is used as an abrasive 36 in the following Example 1 to have an average shot particle diameter of 45 μm.
Is introduced. The abrasive 36 has a substantially spherical shape.

A 6Al4V titanium alloy, which is a product W to be treated, is charged into the barrel in the cabinet 31 from the entrance 35 through the inlet / outlet 35, and the shot is injected at a jet pressure of 0.6 MPa or more, a jet speed of 80 m / sec or more, and a jet distance of 100 mm. Spray on titanium alloy surface.

The blasted abrasive 36 and the dust 37 generated at this time fall into the hopper 38 at the lower part of the cabinet 31, rise by the ascending airflow generated in the conduit 43, and are sent into the collection tank 33. The abrasive 36 is collected. The dust 37 in the collection tank 33 is guided from the upper end of the collection tank 33 to the dust collector 34 via the pipe 42 by the airflow in the collection tank 33, and is accumulated at the bottom of the dust collector 34. It is released from a haiku blower 39 provided at the top.

When a nitrogen cylinder (not shown) is used as a compressed gas supply source and nitrogen is supplied as compressed gas through the pipe 44, the titanium powder is pressure-fed together with nitrogen as described above, and 6Al4 in the barrel of the cabinet 31
V Injected into titanium alloy.

The following table summarizes the blasting conditions performed by the above blasting apparatus.

[0046]

[Table 1] Example 1

In the above-mentioned treatment, when titanium, which is an injection powder, is injected with nitrogen gas, a TiN film is formed on the surface of the 6Al4V titanium alloy, and the surface becomes golden, the surface hardness increases, the appearance is improved, and the commercial value is improved. .

Embodiment 2

[0049]

[Table 2]

In the above-described treatment, when titanium, which is an injection powder, was injected with nitrogen gas, a TiN film was formed on the surface of SUS304, and the surface became gold, the surface hardness was increased, the appearance was improved, and the commercial value was improved.

[Embodiment 3]

[0052]

[Table 3]

In the above treatment, when aluminum, which is an injection powder, was injected with nitrogen gas, an AlN film was formed on the surface of the ADC 12 to become gray, the surface hardness was increased, and the life of the sliding portion was greatly extended. .

Also, by using nitrogen as the injection gas, sparks generated at the time of collision between the injection powder and the product to be processed do not occur,
In addition, aluminum dust explosion can be prevented, which is safe.

Next, the room temperature nitriding treatment in the present invention will be demonstrated by comparing the compressed gas with air and nitrogen.

Embodiment 4

[0057]

[Table 4]

According to the SEM image (X-ray analysis), (label: 7 N
K α, full scale (cps 125), label: 13 Al K
α, full scale 5000) Approximately 15 microns of the surface layer is nitrided, confirming the above hardness increase.

Example 5 The following shows the compressive residual stress.

[0060]

[Table 5]

From Example 5 described above, the processed articles 7 to 8 μm were tickered, and the zirconia was dispersed and micro-nitridation was performed simultaneously, thereby improving heat resistance and abrasion resistance. Further, when nickel plating was performed on the upper surface and tin plating was performed on the side surfaces, heat resistance and sliding wear resistance were remarkably improved.

Embodiment 6

[0063]

[Table 6]

In Example 6, the surface of the article to be treated
A tin film was formed on μ, and it was found from the increase in compressive residual stress that micronitriding was performed by nitrogen gas treatment.
When the treated product was used as a multi-layer belt, remarkable wear resistance, prolonged life and a silencing effect were recognized.

[Brief description of the drawings]

FIG. 1 is an overall view of a gravity type sandblasting apparatus used in an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 30 Gravity type blast device 31 Cabinet 32 Nozzle 33 Recovery tank 34 Dust collector 35 Doorway 36 Abrasive material 38 Hopper 39 Air blower 41 Pipe 42 Pipe 43 Pipe 43 Pipe

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C23C 24/04 C04B 41/80 C23C 8/24

Claims (11)

(57) [Claims] 1. A nitrogen metallic product having reactive components or the metallic product and comprising a mixture of ceramic to be treated-products and the injection powder or propellant powders or we made with the treated-products and nitrogen-reactive component consisting of ceramics The surface of the article to be treated or the film formed on the surface of the article to be treated is coated with the nitrogen reactant under a nitrogen gas atmosphere.
A micro-nitrided article formed by diffusing and infiltrating a nitride produced by a chemical reaction in the above . 2. A blasting process using a metal product having a nitrogen reaction component or a product to be processed comprising a mixture of the metal product and ceramics, or a product to be processed comprising ceramics and an injection powder having a nitrogen reaction component. A mixed fluid consisting of the sprayed powder and nitrogen gas is sprayed onto the surface of the article to be treated, and a nitrogen compound produced by a chemical reaction between the article to be treated and / or the sprayed powder having the nitrogen reaction component and the nitrogen gas is covered. A micro-nitriding method characterized by diffusing and infiltrating the surface of a treated product. To 3. A metallic product or ceramic or treated surface of the finished product consisting of a mixture thereof, diffusion osmosis or coated with a ceramic coating formed comprising the compounds formed by the chemical reaction of the injected powder and a reactive propellant gas object. 4. A blasting process using a reactive injection gas injects a mixed fluid comprising an injection powder and the reactive injection gas onto a surface of a workpiece to be processed comprising a metal product, ceramics, or a mixture thereof. And a compound produced by a chemical reaction between the spray powder and the reactive spray gas is diffused infiltrated or coated on the surface of the article to be treated. 5. The method according to claim 2, wherein the reactive injection gas is one kind or a mixed gas containing nitrogen. 6. The method of claim 3, wherein the sprayed powder is a metal, a ceramic, or a mixture thereof. 7. The finely-nitrided product according to claim 1, wherein the shape of said sprayed powder is substantially spherical or polygonal. Molding method. 8. The size of the sprayed powder is 200 to 20 μm.
m, preferably 100 to 20 µm. 9. An injection speed of the injection powder is 80 m / se.
The method for molding a finely nitrided molded product or the method for molding a ceramic coated molded product according to any one of claims 2 or 4 to 8, wherein the molding is performed at c or more or at an injection pressure of 0.3MPa or more. 10. At least a surface of the article to be treated and / or
The method for forming a micro-nitrided product or the method for forming a ceramic-coated product according to any one of claims 2 to 4, wherein the reactive injection gas is heated. 11. The method according to claim 4, wherein the reactive injection gas is nitrogen.