JP5858431B2 - Method for forming fluoride sprayed coating and member coated with fluoride sprayed coating - Google Patents

Description

  The present invention relates to a method for forming a fluoride sprayed coating and a member coated with a fluoride sprayed coating, and in particular, on the surface of a member for a semiconductor processing apparatus that is subjected to plasma etching in an environment where various halogen gases and halogens are present. We propose a method of coating a fluoride spray coating excellent in corrosion resistance and plasma etching resistance by firmly attaching it, and a fluoride spray coating coating member obtained by carrying out this method.

  Equipments such as dry etchers, CVD, and PVD used in semiconductor processing and liquid crystal manufacturing processes need to improve the precision of microfabrication associated with the high integration of circuits formed on substrates such as silicon and glass. As for the processing environment, higher cleanliness is required. On the other hand, in various processes for microfabrication, highly corrosive gas or aqueous solution such as fluoride and chloride is used. As a result, secondary environmental pollution caused by corrosion products cannot be ignored.

Semiconductor device manufacturing / processing steps belong to a so-called dry process in which a compound semiconductor composed mainly of Si, Ga, As, P, or the like is used and processed in a vacuum or a reduced pressure environment. In this dry process, various types of film formation, impurity implantation, etching, ashing, cleaning, and the like are repeatedly performed in the environment. Equipment and members used in such dry processes include oxidation furnaces, CVD equipment, PVD equipment, epitaxial growth equipment, ion implantation equipment, diffusion furnaces, reactive ion etching equipment, and piping attached to these equipment, There are components and parts such as exhaust fans, vacuum pumps, and valves. Moreover, these devices include fluorides such as BF ₃ , PF ₃ , PF ₆ , NF ₃ , WF ₃ , HF, BCl ₃ , PCl ₃ , PCl ₅ , POCl ₃ , AsCl ₃ , SnCl ₄ , TiCl ₄ , It is known to use highly corrosive agents and gases such as chlorides such as SiH ₂ Cl ₂ , SiCl ₄ , HCl and Cl ₂ , bromides such as HBr, NH ₃ and CH ₃ F.

In the dry process using a halide, plasma (low temperature plasma) is often used to activate the reaction and improve processing accuracy. In the plasma usage environment, various halides form highly corrosive atomic or ionized F, Cl, Br, and I, and exert a great effect on fine processing of semiconductor materials. Particles such as fine SiO ₂ , Si ₃ N ₄ , Si, and W that have been scraped off by the etching process float in the processing environment from the surface of the semiconductor material (particularly plasma etching process), and these are being processed Alternatively, there is a problem that the quality of the processed product is remarkably deteriorated by adhering to the surface of the device after processing.

As one of countermeasures against these problems, there is conventionally a method of treating the surface of a semiconductor manufacturing / processing apparatus member with aluminum anodic oxide (alumite). In addition, oxides such as Al ₂ O ₃ , Al ₂ O ₃ .Ti ₂ O ₃ , Y ₂ O ₃ , oxides of Group IIIa metal of the periodic table are sprayed or vapor-deposited (CVD method, PVD method) For example, there is a technique of coating the surface of the member by using the above, or using these as a sintered body (Patent Documents 1 to 5).

More recently, plasma erosion resistance has been improved by irradiating the surface of Y ₂ O ₃ , Y ₂ O ₃ -A1 ₂ O ₃ sprayed coating with a laser beam or electron beam to remelt the surface of the sprayed coating. The technique to make it appear also (patent documents 6-9).

There is also a proposal of using a fluoride coating of a metal element belonging to a halogen compound as a corrosion-resistant coating for a member for a semiconductor processing apparatus. For example, Patent Document 10 discloses a method in which a surface of a ceramic sintered body such as silicon nitride or silicon carbide is coated with a rare earth element or alkaline earth element fluoride by a magnetron sputtering method, a CVD method, a thermal spraying method, or the like. Patent Document 11 has a proposal for a member in which a YF ₃ film is formed on an A1 ₂ O ₃ base material.

  Patent Document 12 discloses a method for producing a susceptor using a powder mainly composed of a fluoride of Y and a lanthanoid element, and Patent Documents 13 and 14 include fluoride particles of Group IIIa elements in the periodic table. A technique is disclosed in which a film is formed by a thermal spray heat source such as an inert gas plasma or a combustion gas flame, and then heat treatment at 200 ° C. to 250 ° C. is performed to change the crystal into stable orthorhombic crystals.

  Further, Patent Document 15 proposes a spraying particle for rare earth-containing mixture (oxide, fluoride, chloride) containing Y of particles granulated from primary particles having an average particle diameter of 0.05 μm to 10 μm. Patent Document 16 discloses a technique that uses a cold spray method or an aerosol deposition method in addition to a plasma spray method at a high heat source temperature as a method for forming a fluoride spray coating.

JP-A-6-36583 Japanese Patent Laid-Open No. 9-69554 JP 2001-164354 A Japanese Patent Laid-Open No. 11-80925 JP 2007-107100 A Japanese Patent Laid-Open No. 2005-256093 JP 2005-256098 A JP 2006-118053 A JP 2007-217779 A Japanese Patent Laid-Open No. 11-80925 JP 2002-001865 A JP 2001-351966 A JP 2004-197181 A Japanese Patent Laid-Open No. 2005-243988 JP 2002-302754 A JP 2007-115973 A JP 2007-308794 A

  In the present invention, in particular, the following problems related to the fluoride spray coating formed by the thermal spraying method and the coating forming method among the above-described conventional techniques are improved, and the halogen corrosion resistance and plasma erosion resistance are improved. The aim is to propose an excellent fluoride spray-coated member and a method for forming the same.

(1) The following phenomenon occurs when a film is formed by a thermal spraying method using a combustion flame such as inert gas (Ar, He) plasma, hydrocarbon gas, or kerosene as disclosed in Patent Document 12. That is, in the thermal spraying method using plasma as a heat source, fluoride particles flying in a high temperature jet flame are exposed to a high temperature environment of 5000 ° C. to 7000 ° C., and even a combustion flame is 2000 ° C. to 2800 ° C. Since a high temperature atmosphere is configured, in any heat source, some of the fluoride particles induce a thermal decomposition reaction and an oxidation reaction, and F ₂ gas is released.

Then, with the release of the F ₂ gas, the components of the fluoride particles are changed, and the formed fluoride film is stoichiometrically changed. For example, when plasma spraying is performed using YF ₃ particles, it is presumed that F ₂ gas is released in the heat source and changes to a fluoride represented by YF _3-X .

However, it is presumed that the halogen resistance of the yttrium fluoride sprayed coating represented by YF _3-X is chemically unstable as compared with the film forming fluoride particles (YF ₃ ). This is about the yttrium fluoride film in paragraph (0010) of Patent Document 13. “It was found that the color of the yttrium fluoride film is changed by corrosive halogen gas only by using yttrium fluoride. It can be seen from the description that “it was found that corrosion resistance is not sufficient by using yttrium fluoride alone and the yttrium fluoride film is depleted.”

(2) Further, in the technique disclosed in Patent Document 13, as a measure for changing the color of the coating and reducing corrosion resistance, the amorphous fluoride sprayed coating immediately after film formation is subjected to heat treatment at 200 ° C. to 500 ° C. A technology to change to orthorhombic is proposed. However, even if this method is applied, as described in paragraph (0014) of this document 13, the change in the color of the film is reduced, and this is not a drastic measure.

(3) Furthermore, as for the method of forming a fluoride film described in Patent Document 16, the paragraph (0021) describes that a cold spray method, an aerosol deposition method, or the like is desirable. On the other hand, when it is applied as a thermal spraying method, it is stated that “if a hydrogen gas is further mixed with a plasma gas such as argon or helium, the plasma temperature becomes high and a denser film can be formed”. However, the cold spray method is according to the Journal of the Japan Thermal Spray Association, “Spraying Technology Vol. 26 No. 2/3, published on January 31, 2007, pages 18 to 25, overview of cold spray and trends in research and development” , Ar, N ₂ , He, or other inert gas is heated to 500 ° C., and film-forming particles are sprayed at a high speed of 300 to 1200 m / S.

  In this method, there is an explanation that the gas at 500 ° C. is lowered to room temperature due to the adiabatic expansion phenomenon in the sprayed portion of the nozzle. Under these conditions, it cannot be said that the method is suitable for forming a fluoride film.

Further, Patent Document 16 does not explain the detailed contents of the cold spray method necessary for forming the fluoride film. That is, in order to further increase the plasma heat source temperature of the plasma spraying method, which is significantly higher than that of the cold spray method, the film is formed by increasing the plasma temperature by mixing H ₂ gas into an inert gas such as Ar or He. Although the method of forming a fluoride film is recommended, on the other hand, although there is a technical contradiction such as the ability to form a film at a low gas temperature by the cold spray method, the reason is completely mentioned. Not done.

(4) Moreover, in the method of heat-treating the fluoride sprayed coating as in Patent Documents 13 and 16, in addition to the increase in the manufacturing process, there is a problem that the production efficiency is reduced and the cost is increased. However, there was a problem that the corrosion resistance of the film could not be sufficiently recovered.

(5) Further, in the process of forming a fluoride sprayed coating by the atmospheric plasma spraying method or the high-speed flame spraying method, the fluoride particles for film formation are thermally decomposed in a high-temperature heat source, and harmful F ₂ gas with a strange odor is generated. , The work environment is deteriorated and there is a problem in work safety and health.

(6) Furthermore, although the fluoride sprayed coating has excellent halogen resistance, it has a drawback of poor adhesion to the substrate. However, there are few prior art documents describing this cause and countermeasures. Moreover, even if it is disclosed, it is only an application of a general blast treatment, and the intention to improve the adhesion of the fluoride spray coating is not recognized.

For example, Patent Document 13 and Patent Document 16 only disclose that the surface of the substrate is roughened with steel balls or corundum (Al ₂ O ₃ ), and Patent Document 17 discloses roughening with Al ₂ O ₃ . In addition, there is no description about the blast roughening treatment and the undercoat material as measures for improving the adhesion of the film, and the surface roughness is not disclosed.

(7) Moreover, each of the above-mentioned patent documents employs a method in which a fluoride sprayed coating is directly formed on the surface of a substrate, and conditions for blasting as a pretreatment for forming a fluoride sprayed coating Since there is no description about the necessity of undercoat construction, it is clear that the adhesion of the fluoride sprayed coating is not considered important, and despite this, the coating often peels off. However, no investigation was made on the solution.

  Therefore, an object of the present invention is to provide a fluoride sprayed coating coating member in which a fluoride sprayed coating having good quality characteristics by suppressing thermal decomposition reaction and oxidation reaction is firmly adhered to the surface of a substrate. And providing a method for forming a coating by firmly attaching the coating.

  The present invention is a conventional fluoride spray coating forming method formed by a thermal spraying method with a high heat source temperature as a result of earnest research to overcome the above-mentioned problems of the prior art and reliably realize the above object. Then, there was a problem that the chemical and physical characteristics of the coating were unstable and the adhesion was small. To solve this problem, it was advantageous to adopt a new sprayed coating formation method from the following viewpoints. As a result, the present invention was conceived.

(1) Fluoride for film formation (spraying material) is a film-forming fluoride that is a single or mixed inert gas such as Ar, N ₂ , and He heated to a temperature of about 600 ° C. to 1300 ° C. Use as a fluid drive source of particles is advantageous.
(2) The film-forming fluoride spray material is jetted in the heat source at a high speed of 500 m / second or more. As a result, the coating has a flocking structure in which at least a part of the flying sprayed particles adheres to the concave portion of the adherend surface (such as the substrate surface) because it collides with the substrate surface with a large kinetic energy. It becomes. Therefore, the adhesion of the film can be improved.
(3) The base material for coating the fluoride sprayed coating is degreased, descaled or abrasive particles such as A1 ₂ O ₃ or SiC in accordance with the ceramic sprayed coating work standard specified in JIS H9302 in advance. It is preferable to form a concavo-convex surface by performing a blast roughening treatment using or to preheat.
(4) Prior to the formation of the fluoride film on the surface of the base material after the pretreatment, carbide cermets such as WC-Co and WC-Ni-Cr are subjected to high-speed flame spraying, so that at least a part of the surface of the base material is formed. The sprayed particles of carbide cermet are sparsely stabbed like a pile to form a sprayed particle scattered portion of carbide cermet, and through the sprayed particle scattered portion, the above (2) It is preferable to form a fluoride sprayed coating by a method.
(5) The sprayed particle interspersed part using the carbide cermet is a non-film-like part in which the sprayed particles of the carbide cermet are sparsely scattered in an area ratio (ratio covering the described surface) of 8 to 50%. It is preferable that it is the part which becomes. This portion is distinguished from the undercoat layer of the carbide cermet in which the entire surface of the base material is coated with a substantially uniform thickness to form a film.
(6) The distance between the nozzle of the thermal spray gun using a low-temperature inert gas as the driving source and the substrate surface is kept at 5 to 50 mm. By this, it is preferable to coat and form a fluoride sprayed coating having excellent adhesion.

The present invention developed from such a viewpoint first pretreats the surface of the base material, and carbide cermet particles are applied to the surface of the base material after the pretreatment at a flight speed of 150 to 600 m / sec. , Preferably 300 to 600 m / sec. Spraying at a spraying speed of at least a portion of the sprayed particles of the carbide cermet is sparse at an area ratio of 8 to 50% and the tip of the sprayed particles is sparsely formed on the substrate surface and The sprayed particles of carbide cermet adhering in the state of being pierced in this way are formed, and then, the sprayed material is coated with Ar or N ₂ on the sprayed particles of the substrate and carbide cermet. , He or a mixed gas thereof, and a spray gun using an inert gas as a film forming working gas, in a spray atmosphere maintained at a temperature of 600 ° C. to 1300 ° C., flight speed: 500 m / sec. Spraying at the above speed, the sprayed particles of fluoride adhere to the surface of the substrate so as to bite into the gaps between the particles of the sprayed particles of the carbide cermet. This is a method for forming a film.

Further, the present invention comprises a base material and a fluoride spray coating coated on the substrate surface, the base material, 8-50 percent of the area of the surface, WC-Co, WC-Ni- It is covered with a non-film-form sprayed particle interspersed portion of one or more carbide cermets selected from Cr, WC—Co—Cr and Cr ₃ C ₂ —Ni—Cr , and at least one of the sprayed particle interspersed portions The part is formed by sparsely depositing carbide cermet spray particles on the surface of the base material , and the other part is adhered to the substrate surface or buried in the base material. are those comprising Te, and the fluoride spray coating, fluoride spraying, characterized in that it is one that is formed to cover the substrate from above the Katsuso through the spray particles interspersed section A coating member is proposed.

In the present invention,
(1) pre-Symbol pretreatment, degreasing, it de-scale, either one or more roughening of the substrate surface,
(2) The surface roughening treatment is performed by a surface roughening treatment in which an abrasive such as Al ₂ O ₃ or SiC is blown, so that the surface roughness is Ra: 0.05 to 0.74 μm, and Rz: 0.09 to 2. To 0 μm,
(3) The base material is any of Al and alloys thereof, Ti and alloys thereof, steel containing carbon, various stainless steels, Ni and alloys thereof, oxides, nitrides, carbides, silicides, and carbon sintered bodies. Being
(4) The sprayed particle interspersed portion of the carbide cermet is made of one or more kinds of carbide cermet particles selected from WC—Co, WC—Ni—Cr, WC—Co—Cr, Cr ₃ C ₂ —Ni—Cr and the like. The non-film-like part of the state where the particles that have been sprayed and stabbed loosely on the surface of the substrate are forested,
(5) The sprayed particle interspersed portion of the carbide cermet is formed by spraying a carbide cermet material onto the surface of the base material, and adjusting the flying speed of the particles to 150 to 600 m / sec. , Preferably 300 to 600 m / sec. A layer formed by spraying at a spraying speed of at least a portion of the carbide cermet sprayed particles with an area ratio of 8 to 50% sparsely and stuck like a pile Being
(6) In order to form a sprayed particle scattered portion of non-film carbide cermet on the surface of the substrate, a commercially available high-speed flame spraying device (gun) after roughening the surface of the substrate with the abrasive particles Is used to supply carbide cermet particles such as WC—Co and Cr ₃ C ₂ —Ni—Cr to the spray gun in an amount of 100 to 200 g / min. When the spray gun repeatedly moves on the substrate surface, the moving speed is set to 300 to 1000 mm / sec. In a controlled condition, spraying (mobile) than 5 times the number of, preferably by performing the following operation 3 times, the spray particles interspersed portion of the carbide cermet consisting proportion of 8-50% by area ratio Forming,
(7) The fluoride spray coating is composed of Mg in the periodic table group IIa, Al in the periodic table group IIIb, Group IIIa in the periodic table Y, lanthanoid metal (La), atomic number 57 to 71, and cerium. (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), eurobium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), one or more kinds of fluoride particles selected from fluorides of lutetium (Lu) are sprayed to form a film thickness of 20 μm to 500 μm. Being formed,
(8) The distance between the tip of the thermal spray nozzle for injecting fluoride particles and the substrate surface is set to 5 to 5 in a thermal spray container of 600 ° C. or higher and 1300 ° C. or lower filled with the working gas for film deposition ejected from the thermal spray gun. Holding at 50 mm,
(9) The fluoride sprayed coating has a thickness of 20 to 500 μm,
(10) The substrate is heated to a temperature of 80 to 700 ° C. prior to spraying fluoride.
(11) The spraying speed of spraying particles of fluoride is 600 m / sec. According to the area ratio. Or more, more preferably 650 m / sec. The upper limit of the flight speed is 1000 m / sec. Hereinafter, preferably 800 m / sec. To:
However, this is a more preferable solution.

According to the present invention having the above-described configuration, the following effects can be expected.
(1) Since the spray heat source for heating the fluoride spray particles for film formation uses an inert gas such as Ar, N ₂ , and He, the fluoride particles flying in the spray heat source are oxidized, It reaches the adherend surface without alteration and becomes a sprayed coating. That is, the oxidation reaction is suppressed due to the thermal spraying in a non-oxidizing atmosphere, and the stable performance is obtained without impairing the original performance of the fluoride.
(2) The thermal spray heat source temperature of the inert gas for heating the fluoride particles is as follows: heat source temperature of general plasma spraying method: 5000 ° C. to 7000 ° C., heat source temperature of high-speed flame spraying method: 1800 ° C. to 2800 ° C. Compared to the above, since it is in a much lower temperature range of 600 ° C. to 1300 ° C., a thermal spray coating that suppresses the thermal decomposition reaction of fluoride particles and does not cause chemical mass change and accompanying physicochemical property deterioration. Can be formed.
(3) Furthermore, since the speed of the fluoride particles flying in the inert gas is set to 500 m or more per second, the temperature exposure time of the particles is short (1/1000 seconds), and the above (1), (2) In addition to further improving the effect of the above, by increasing the collision energy to the substrate surface obtained by applying large kinetic energy to the fluoride particles, the tip of the flying spray particles becomes sparse and piled with carbide cermet spray particles The thermal spray coating is coupled with the presence of the carbide cermet, trapped in the inter-particle gaps of the sprayed particles scattered by the pierced and pierced and skewed into the tip of the carbide cermet. It is possible to obtain an improvement in the adhesion strength.
(4) By aligning the above-mentioned conditions such as low temperature, inert gas heat source, high speed flying particles, etc., high vapor pressure fluoride particles (for example, AlF) at high temperatures that could not be formed by the current plasma spraying method etc. ₃ ) and the like can be easily formed.
(5) In addition to the conditions for the thermal spraying method, the surface of the substrate for depositing the thermal spray coating is subjected to a roughening treatment by blasting, and a pretreatment for preheating to 80 ° C. to 700 ° C. is performed. Thereafter, it is possible to improve the presence of the sprayed particle interspersed portion of the carbide cermet and the adhesion / deposition effect composed of the flocked structure of fluoride particles colliding with the substrate surface.
(6) In particular, a hard carbide cermet particle such as WC—Ni—Cr, Cr ₃ C ₂ —Ni—Cr or the like is sprayed and pierced on the roughened surface of the base material by a high-speed flame spraying method. ) When the sprayed particle sparsely pierced state of the carbide cermet particles is introduced by introducing the stopped state, the adhesion deposition rate and the adhesion strength of fluoride sprayed material particles are further improved. I can plan.
(7) Since fluoride has a small surface energy, the mutual bonding force of fluoride particles constituting the film and the adhesiveness to the substrate are low, and there is a defect that the fluoride often peels off. In this respect, according to the present invention, fluoride and carbide cermet (carbon is the main component) has a strong chemical affinity with each other and wets well. In addition to the physical adhesion mechanism of the chemical particles, it is possible to improve the adhesion of the film using a synergistic action with chemical affinity.

It is the figure which showed the flow of the process for implementing this invention method. The surface of the base material which sprayed WC-12mass% Co cermet particle | grains in the speckled state by the high-speed flame spraying method, and the SEM image of a cross section are shown. (A) is a surface sprayed with the cermet particles (b) is an enlarged photograph of the same as the above (c) is a cross section of a substrate on which cermet particles are sprayed It is a basic diagram of the apparatus for low-temperature sprayed coating formation utilized with the method of this invention. It is a basic diagram of the other apparatus for low-temperature sprayed coating formation utilized with the method of this invention. It is a photograph of YF ₃ sprayed coating formed by the method of the present invention. (A) Photograph of film surface (b) Photograph of film cross section

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the flow of steps for carrying out the method of the present invention. Hereinafter, the present invention will be described in the order of the steps.
(1) Base Material The base material that can be used in the present invention includes Al and its alloys, Ti and its alloys, various alloy steels including stainless steel, carbon steel, Ni and their alloys, and the like. In addition, ceramic sintered bodies such as oxides, nitrides, carbides, silicides, and sintered carbon materials may be used.

(2) Pretreatment The pretreatment is preferably performed on the surface of the base material in accordance with a ceramic spraying work standard defined in JIS H9302. For example, not only degreasing and descaling to remove rust and oils on the surface of the substrate, but also roughening by spraying grinding particles such as Al ₂ O ₃ , SiC, etc. Make it easy. The roughness after roughening is preferably about Ra: 0.05 to 0.74 μm and Rz: about 0.09 to 2.0 μm. In addition to this, it is also effective to preheat the substrate to 80 to 700 ° C. in advance.

(3) Formation of sprayed particle interspersed portion of carbide cermet particles The surface of the base material roughened by blasting is processed by the same method as the high-speed flame spraying method or the inert gas spraying method specific to the present invention described later. The carbide cermet particles having a diameter of 5 to 80 μm are sprayed at a high speed, and the tip of at least a part of the sprayed hard carbide cermet spray particles is pierced into the surface of the base material in an independent state so that the pile stands. To be in a proper state. In addition, by such a method, sprayed particle interspersed portions in which carbide cermet particles adhere to the base material surface in a sparse pattern are formed. In this case, if the particle size of the carbide cermet particles is smaller than 5 μm, the amount supplied to the spray gun is uneven and uniform spraying is not possible, and the amount of piercing is reduced and effective sprayed particle interspersed portions are formed. become unable. On the other hand, when the particle diameter exceeds 80 μm, the piercing effect is weakened.

  This sprayed particle interspersed portion is obtained by applying a carbide cermet material (particle size of 5 to 80 μm) to 150 to 600 m / sec. , Preferably 300 to 600 m / sec. Using a spray gun with a flying speed of 5 mm, the number of spraying is set to 5 times or less, preferably 3 times or less, and the sprayed particles are sparse and piled on the surface of the base material in the area ratio of 8 to 50%. It is the part made to adhere in the state stabbed like.

  The sparsely dispersed carbide cermet sprayed particle interspersed portion in this processing step is not completely film-formed, but has the following structure. That is, the WC-Co cermet sprayed as shown in FIGS. 2 (a) and 2 (b) showing the appearance when the particles of the carbide cermet material of WC-12mass% Co are sprayed on the surface of the SUS310 steel substrate. Part of the particles is in a state of sticking to a portion of 8 to 50% of the surface of the base material so as to pierce and reduce like a pile. The other WC-Co cermet particles are also dispersed and adhered in a state of being pulverized by the collision energy to the substrate surface, and the other part is completely buried in the substrate. As a result, a reinforcing layer made of carbide cermet is formed on the surface layer of the sprayed coating.

  Moreover, FIG.2 (c) observes the distribution state of the sprayed WC-Co cermet particle | grains which exist in a base-material surface layer part in a cross-sectional state. As is clear from this photograph, the WC-Co cermet particles exist in a state where small piles are sparsely forested by being driven into the surface of the base material, and the other part is simply attached or buried. It has become. In the present invention, on the surface of the substrate in such a state, that is, on the sprayed particle interspersed portion with the carbide cermet particles adhering in such a state (this is not a complete film shape). When fluoride particles are sprayed, a highly sprayed fluoride coating is formed by utilizing the mutual entanglement effect (planted structure) and skewering phenomenon of hard WC-Co cermet particles fluorinated spray particles grown in piles. It is something to try.

  In addition, about the said sprayed particle interspersed part, in this invention, a white part is a carbide | carbonized_material cermet sprayed particle, and a black part is a base material with an image analysis apparatus using the SEM photograph of FIG. 2 (a) or FIG. As an exposed surface, the area ratio (area occupancy) of the carbide cermet particles was determined. As a result, it was confirmed that the area ratio is preferably in the range of 8 to 50%. If it is 8% or less, the effect of roughening by the carbide cermet particles is low, and if it is 80% or more, the same mechanism of action as the undercoat layer of the carbide cermet is obtained, and the piercing effect of fluoride particles is reduced. . In the present invention, the state of the substrate surface sprayed in the range of 8 to 50% of the area ratio of the carbide cermet spray particles is referred to as “sprayed particle interspersed portion”.

As the carbide cermet material, WC—Ni—Cr, WC—Co—Cr, Cr ₃ C ₂ —Ni—Cr, or the like can be used in addition to the exemplified WC—Co. The ratio of the metal component in the carbide cermet is preferably in the range of 5 to 40 mass%, particularly preferably 10 to 30 mass%. When the metal component is less than 5 mass%, the hard carbide is scattered as a small powder, while when the metal component is more than 40 mass%, the hardness and corrosion resistance are lowered, and the effect of wedge fastening is reduced. The substrate may be corroded by the corrosive gas entering through the pores of the fluoride spray coating.

(4) Preheating of base material Prior to fluoride spraying, the base material after forming the sprayed particle interspersed portion with loosely attached carbide cermet particles accompanying the spraying treatment of the base material and carbide cermet particles is preheated. . The preheating temperature is preferably controlled according to the base material, and the following temperatures are recommended.
(I) Al, Ti and alloys thereof: 80 ° C to 250 ° C
(Ii) Steel (low alloy steel): 80 ° C to 250 ° C
(Iii) Stainless steel: 80 ° C to 250 ° C
(Iv) Ceramic sintered bodies such as oxides and carbides: 120 ° C to 500 ° C
(V) Sintered carbon: 200 ° C to 700 ° C

The preheating may be performed in the air, in a vacuum, or in an inert gas, but it is necessary to avoid an atmosphere in which the base material is oxidized by preheating and an oxide film is formed on the surface.
In the method of the present invention, one of the biggest reasons for preheating the substrate is that when an inert gas is injected from the nozzle at a high speed, the gas temperature of, for example, about 600 ° C. reaches about 50 ° C. due to the cross-sectional expansion phenomenon of the gas. This is because there is a risk that the temperature of the base material is lowered and the base material is thereby cooled. If the surface temperature of the substrate becomes such a low temperature, the fluoride spray particles ejected from the nozzle (the melting point of the fluoride is YF ₃ (1152 ° C.), the case of ErF ₃ (1350 ° C.)) If the material collides with the surface of the substrate without melting in the gas, most of the material will scatter and the probability of film formation will be very low. This is because it causes a deterioration in quality such as a film having a low porosity and a high porosity.

  The present invention provides roughening of the surface of the base material, formation of sprayed particles scattered on the surface of the sparsely coated carbide cermet particles, preheating of the base material and fluoride particles by an inert gas described later. The adhesion force of fluoride particles is improved by a large kinetic energy by hot high-speed spraying.

(5) Formation of fluoride spray coating (top coat) a. Fluoride spray material The fluoride spray material used in the present invention includes elemental periodic group IIa group Mg, periodic table group IIIb group Al, periodic table group IIIa group Y, and lanthanoids belonging to atomic numbers 57-71. It is a fluoride of a metallic metal. The metal element names of atomic numbers 57 to 71 are lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd). , Terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu) can be used.

  And as a thermal spray material, what adjusted the particle size of the said metal fluoride particle to 5-80 micrometers is used. That is, if the sprayed material is fine particles of 5 μm or less, there is a disadvantage that more particles are scattered when colliding with the surface of the substrate, and if the particles are larger than 80 μm, the feed rate to the spray gun is uniform. This is because, on the other hand, the tendency of the pores of the formed film to become large becomes remarkable.

  The sprayed coating with fluoride particles formed on the surface of the substrate after the roughening or carbide cermet sprayed particles and further on the substrate surface after preheating should have a thickness of 20 to 500 μm. A range of 50 to 200 μm is preferred. This is because a film thinner than 20 μm cannot obtain a uniform film thickness, and if it is thicker than 500 μm, the residual stress at the time of forming a fluoride film increases and the film is easily peeled off.

(B) Thermal spraying apparatus and film forming method As an apparatus used in carrying out the present invention, the low temperature thermal spray coating member described in the patent number 4628578 previously proposed by the inventors and the apparatus used in the manufacturing method thereof are used. be able to. FIG. 3 and FIG. 4 show a preferred example of an apparatus effective in forming the fluoride sprayed coating according to the present invention on the surface of the substrate in such an apparatus. In the figure, l is a working gas source supplied from a compressed gas cylinder, 2 is a spraying material supplier, 3 is a gas pressure heat exchanger, 4 is a spraying container, 5 is a spray gun, 6 is a nozzle, and 7 is a workpiece. , 8 is a silencer, 9 is a main gas pipe for working gas, 10 is a sub-gas pipe for conveying the sprayed material powder, 11 is a rectifying plate for working gas, and 12 and 13 are flow control valves provided in the respective gas pipes. It is.

  These illustrated apparatuses divide the high-pressure inert gas supplied from the working gas source 1 into two, send one of the gases as the working gas to the heat exchanger 3 and heat it to 600 to 1300 ° C. The jet gas is jetted from the nozzle 6 toward the workpiece 7 as a sonic flow jet gas. In this case, temperature control is performed so as to prevent an extremely low temperature accompanying adiabatic expansion. Preferably it is 700 degreeC, More preferably, it is 800 degreeC or more, On the other hand, it is preferable that the upper limit temperature shall be 1000 degreeC. On the other hand, the preferable upper limit temperature is about 1000 ° C.

  When the temperature of the working gas is less than 600 ° C., the temperature is lowered to around 50 ° C. due to the adiabatic expansion phenomenon at the outlet of the injection gun, and the temperature rise effect of the fluoride particles cannot be expected. On the other hand, when the temperature exceeds 1300 ° C., the energy required for heating the inert gas increases, and the cost for heat-resistant measures for the attached equipment increases.

  The other branched gas is used as a gas for conveying the spray powder material, but is merged with the working gas in the spray gun 5 to form a supersonic gas flow in the nozzle 6 (in the case of FIG. 3). The sprayed material particles are caused to fly and collide toward the object to be processed at a high speed, and sprayed so that a part of the sprayed material bites into the adherend surface and gradually thickened to form a sprayed coating having a predetermined thickness. Further, as shown in FIG. 4, the spray material particles may be supplied from a pressure reducing portion at the outlet of the spray gun 5 (near the attachment portion of the nozzle 6). In any case, the distance between the nozzle 6 and the object to be processed is 5 to 50 mm, preferably 10 to 30 mm. If the distance is smaller than 5 mm, the gas flow is obstructed, and if the distance is larger than 50 mm, the adhesion rate of fluoride particles. Is significantly reduced.

  Fluoride spray material particles are applied at 500 m / sec. From the nozzle 6 of the spray gun 5 using an inert gas as a working gas for film formation. The object 7 is sprayed at the above flight speed. The flight speed at this time is 500 m / sec. The reason for the above is 500 m / sec. It is because the adhesion rate of the fluoride particle with respect to the base material surface will fall extremely if less than. The preferred lower limit speed is 600 m / sec. Or more, more preferably 650 m / sec. That's it. The upper limit is 800 m / sec. The following is more preferably 750 m / sec. It is preferable to set the speed to a certain level.

  The supersonic gas generating part (nozzle 6) and the object 7 are protected by the steel spraying container 4, and the shock wave sound generated by the supersonic gas is combined with the action of the silencer 8. The structure is such that it does not leak to the outside.

The characteristic feature of the present invention is that an inert gas such as Ar, N ₂ or He alone or a mixed gas thereof is used as the high-pressure working gas to be used. Moreover, it is suitable to control the pressure of these gases within the range of 0.5 to less than 1.0 MPa. In the present invention, the reason why attention is given to the inert gas as an example as the working gas is that, even if heated to a high temperature of 1300 ° C., various metal members constituting the thermal spraying apparatus are not oxidized and consumed. This is because the physicochemical change due to the oxidation reaction of the particles can be minimized even when the chemical particles are heated. And the reason which makes the pressure less than 0.5-1.0 MPa is because it is suitable for utilizing the kinetic energy of the inert gas for heat sources. The use of a pressure gas of 1 MPa or higher is not a problem in film formation, but requires legal measures in handling high-pressure gas, and is not preferable from the viewpoint of stability of work.

  In the above description, the method used to form the fluoride spray coating has been described using the example of the apparatus used in the low temperature spraying method described in the patent number 4628578 previously proposed by the inventors. A similar low temperature spraying device (cold spray) may be used. Accordingly, for the present invention, any apparatus capable of obtaining the coating formation conditions of the fluoride spray coating, specifically, the type, temperature, flow rate, etc. of the working gas can be used. It is not limited to the above example.

Next, FIG. 5 shows an SEM image of the cross section and the surface of the YF ₃ sprayed coating formed on the substrate surface by the above-described method according to the present invention. It can be seen that the coating is formed on the surface of the substrate with a relatively dense thermal spray coating and in good condition.

(C) Features of Fluoride Sprayed Coating First, the following points can be pointed out as the physicochemical properties of the fluoride itself. That is, although the fluoride film has chemical stability against halogen-based gas as compared with a metal film or ceramic film, the surface energy is small, so the mutual bonding force of the fluoride particles constituting the film and the substrate The adhesion strength is weak. Further, since a large residual stress is likely to be generated during film formation, peeling of the film often occurs easily due to slight deformation of the base material after film formation. In addition, since fluoride exhibits poor ductility, the film easily “cracks” and causes corrosion of the base material due to internal penetration of acid or alkaline cleaning liquid together with pores generated during film formation. Even if the corrosion resistance of the fluoride itself is good, there is also a problem that the property cannot be used as a corrosion protection film.

  In this regard, according to the present invention, the strength of the thermal spray coating itself improves the mutual bonding force between the particles, in particular, the binding force derived from the flocked structure of the fluoride spray particles, and in particular due to the carbide cermet particles on the substrate surface. In the case where the sprayed particle interspersed portion is provided, the adhesion of the coating is also improved, and the above-mentioned problems that the fluoride has can be solved. That is, the effect of preventing the peeling of the film and cracking and preventing the corrosion of the base material by preventing the intrusion of the cleaning liquid associated therewith occurs.

  The fluoride spray coating formed in conformity with the present invention can be used as it is, but if necessary, heat treatment at 250 ° C. to 500 ° C. is performed after film formation to release the residual stress. In addition, since it is easy to crystallize an amorphous material (orthorhombic system), the present invention does not particularly limit the implementation of these treatments. The reason for limiting the temperature of this heat treatment to the above-mentioned range is that if it is 250 ° C. or lower, it takes a long time to release the residual stress of the coating, and crystallization is insufficient, and if it is 500 ° C. or higher, the fluoride sprayed coating This is because it may promote changes in physicochemical properties.

Example 1
In this example, YF ₃ and AlF ₃ were used as fluorides, and the temperature of the working gas for film formation and the feasibility of forming a fluoride spray coating were investigated.
(1) Substrate: SUS304 steel (dimensions: 30 mm × 30 mm × thickness 5 mm) was used as the substrate, and the surface was preheated to 180 ° C. after blast roughening treatment was used.
(2) Spraying atmosphere: An inert gas composed of Ar, N ₂ and He is used as a working gas for film formation, and each gas temperature is heated from less than 500 ° C. to a maximum of 1300 ° C. The flying speed of the particles is 600 to 660 m / sec. The presence or absence and quality of the fluoride film formed on the surface of the base material was investigated while maintaining the temperature.
(3) Fluoride material for film formation: YF ₃ and AlF ₃ having a particle size of 10 to 35 μm were used as fluorides. Further, as the thermal spraying method of the comparative example, the current atmospheric plasma spraying method using Ar and hydrogen gas as plasma working gas and the low-pressure plasma spraying method (particle flight speed: 350 to 500 m / sec.) Are used, and each plasma jet is used as a heat source. As a film, YF ₃ and AlF ₃ were formed.

(4) Test results Table 1 shows the test results. As is apparent from the results shown in this table, in the thermal spraying method according to the present invention, when the film forming working gas (Ar, N ₂ , He) is less than 500 ° C., no fluoride film is formed (fluoride particles). Even in the case where adhesion was observed, it was confirmed that the formation of a favorable film was observed in appearance with a porous and impractical state) and a gas temperature of 600 ° C. or higher.
On the other hand, in the current atmospheric plasma spraying method and low pressure plasma spraying method, YF ₃ film formation is observed, but the AlF ₃ film has many defects (poor and inferior in uniformity) and is practical. No film properties were obtained. This is presumably because AlF ₃ has a very high vapor pressure, and thus vaporized or decomposed from the surface of AlF ₃ particles when flying in a high-temperature plasma jet.

(Example 2)
In this example, the influence of the film forming method and the roughening method of the base material on the porosity of the fluoride spray coating formed on the surface of SS400 steel was investigated.
(1) Substrate: SS400 steel (dimensions: width 50 mm × length 50 mm × thickness 3.2 mm) was used as the base material, and blast roughening treatment (comparative example) with current alumina particles and WC-12 mass% Co. Particles (numerical values in the following examples indicate mass%) are subjected to a flight speed of 720 m / sec. Two types of spraying treatment were applied under the conditions of the number of spraying times: 6 times and the area ratio: 30 to 32%.
(2) Thermal spraying atmosphere: Ar gas heated to 750 ° C. was used as a working gas for film formation, and the flight speed of YF ₃ particles flying in the atmosphere was set to 650 to 700 m / sec. Controlled to range.
(3) Fluoride for film formation: YF ₃ (particle size: 10 to 40 μm) is formed to a thickness of 120 μm by the present atmospheric plasma spraying method and high-speed flame spraying method as film formation of the method of the present invention and the comparative example. I let you.
(4) Feroxyl test (porosity)
Specifically, the following method was used as a ferroxyl test method. That is, 10 g of potassium hexacyanoferrate (III) and 15 g of sodium chloride are dissolved in 1 liter of distilled water, and the filter paper for analysis is sufficiently impregnated. Thereafter, the filter paper was affixed to the surface of the test piece and allowed to stand for 30 minutes, and then the filter paper was peeled off to visually determine the presence or absence of blue spots on the filter paper surface. This is because the ferroxyl test solution penetrates into the amorphous membrane when penetrating pores are present, reaches the iron substrate interface and generates iron ions, and this reacts with potassium hexacyano (III) and reacts with blue on the surface of the filter paper. It can be determined by generating spots.

(5) Test results The test results are shown in Table 2. As is apparent from the results shown in this table, it was found that blue spots were generated from all the fluoride spray coatings tested, and through pores were present in the coating. However, when looking at the number of blue spots, 3-7 large blue spots are seen in the coatings (Nos. 3 and 4) formed by the atmospheric plasma spraying method and the high-speed flame spraying method of the comparative example. The coating formed by thermal spraying according to the method of the present invention has a small number of spots and shows a tendency toward densification compared to the former. It was also found that the film formed on the surface of the base material sprayed with WC-Co particles has few through pores and can be put to practical use as a pretreatment for forming a fluoride film.

(備考)
(1)供試皮膜の膜厚:120μm
(2)基材のブラスト粗面化処理の粗さ：Ra 0.6〜0.69μ、Rz 1.2〜1.8μm
(3)フェロキシル試験：JIS H8666セラミック溶射皮膜試験方法に準拠

(Remarks)
(1) Test film thickness: 120μm
(2) Roughness of the blast roughening treatment of the substrate: Ra 0.6 to 0.69 μ, Rz 1.2 to 1.8 μm
(3) Feroxyl test: Compliant with JIS H8666 ceramic spray coating test method

(Example 3)
In this example, the flying speed of the fluoride particles and the preheating temperature of the base material were respectively changed to obtain the flying speed and the preheating temperature necessary for forming the fluoride film.
(1) Substrate: Using the same stainless steel as in Example 1, a blast roughening treatment was performed, and a test piece preheated in the range of 20 ° C to 520 ° C was prepared.
(2) Thermal spray atmosphere: Ar gas heated to 750 ° C. was used as the working gas for film formation, and the velocity of the fluoride particles flying through this was set to 500 m / sec. Less than 600-700 m / sec. 750 m / sec. The film was formed under the three conditions.
(3) Fluoride for film formation: YF ₃ (particle diameter: 10 to 35 μm)

(4) Test results Table 3 shows the test results. As is apparent from the results shown in this table, the flight speed of YF ₃ particles is 500 m / sec. If it is less than 1, sufficient film formation could not be obtained even when the preheating temperature of the substrate was changed from 20 ° C to 520 ° C (No. 1). However, the flying speed of the particles is 600 m / sec. As described above, when the preheating temperature of the substrate is maintained at 80 ° C. or more, the film is formed, and this tendency causes the flight speed to be 750 m / sec. Even with the above, there was almost no change, and the formation of a good thermal spray coating was observed. Therefore, the flying speed of the fluoride particles necessary for forming the fluoride film is 600 m / sec. As described above, it has been found that if the preheating temperature of the base material (SUS304 steel) is 80 ° C. to 500 ° C., a predetermined effect can be obtained.

  The maximum preheating temperature of the base material varies depending on the base material quality, and non-ferrous metals such as Al and Ti undergo deformation and metallurgical changes as the temperature rises, and steel materials generate oxide scale on the surface. Since a change occurs, it is preferable to suppress to a low temperature. In this respect, sintered bodies such as carbides and oxides are less affected by the heating temperature, so that a better thermal sprayed film is formed when the production temperature is as high as possible. .

Example 4
In this example, the film formation state due to the difference in the flying speed of the fluoride particles and the roughened state of the substrate surface was investigated.
(1) Substrate: The same SUS304 steel test piece as in Example 1 was used, and the surface was subjected to a blast roughening treatment, and under the same conditions as Example 2 of WC-Co cermet, a sparse pattern by high-speed flame spraying method What performed the spraying process (750 m / sec.) Used as follows was prepared. All the substrates were preheated to 200 ° C.
(2) Thermal spraying atmosphere: Ar gas heated to 700 ° C. is used as the working gas for film formation, and the flying speed of fluoride particles flying in this is less than 500 to 750 m / sec. It was adjusted to become.
(3) Fluoride for film formation: YF ₃ (particle size: 5 to 30 μm)

(4) Test results Table 4 shows the test results. As is apparent from the results shown in this table, the flying speed of the fluoride particles is 500 m / sec. Below, the surface of the substrate was roughened, and the fluoride film was not sufficiently formed, and even if formed, it was porous and non-uniform. When the particle speed is 600 m / S or more, a blast roughened (No. 2) WC-Co cermet particle is sprayed and a good film is formed. Particularly, a film on a test piece sprayed with WC-Co cermet particles is A good appearance was shown (No. 3).

(Example 5)
In this embodiment, a fluoride spray coating is formed on the surface of an Al alloy substrate (dimensions: width 30 mm × length 50 mm × thickness 3 mm) by a method suitable for the present invention, and the plasma etching resistance of the coating is formed. Evaluated.
(1) Substrate: The surface of an Al alloy (A3003 specified in JIS H4000) was subjected to a blast roughening treatment and then preheated to 200 ° C.
(2) Thermal spray atmosphere: He gas heated to 800 ° C. was used as the working gas for film formation, and the flying speed of fluoride particles flying in the gas was set to 650 to 700 m / sec. Controlled to the range.
(3) Fluoride for film formation: YF ₃ , DyF ₃ , CeF ₃ (particle diameter 5 to 45 μm) was used to form a film with a film thickness of 180 μm. In addition, as a film of the comparative example, a film in which Y ₂ O ₃ , Dy ₂ O ₃ , and CeO ₂ were formed to 180 μm by the atmospheric plasma spraying method was evaluated under the same conditions.
(4) Plasma etching atmosphere gas composition and plasma output (i) Atmosphere gas and flow rate conditions (a) F-containing gas: CHF ₃ / O ₂ / Ar = 80/100/160 (flow rate cm ³ per minute)
(B) CH-containing gas: C ₂ H ₂ / Ar = 80/100 (flow rate cm ³ per minute)
(Ii) Plasma irradiation output High frequency power: 1300W
Pressure: 4Pa
Temperature: 60 ° C
(Iii) Plasma etching test atmosphere (a) Conducted in an F-containing gas atmosphere (b) Implemented in a CH-containing gas atmosphere (C) Implemented in an atmosphere in which an F-containing gas atmosphere 1h and a CH-containing gas atmosphere 1h are alternately repeated

(5) Evaluation method In the evaluation of the plasma erosion resistance test, the plasma erosion resistance and the environmental pollution resistance were investigated by measuring the number of particles of the film component scattered from the test film by the etching treatment. The particles were measured by measuring the time required for the number of particles having a particle size of 0.2 μm or more attached to the surface of an 8-inch diameter silicon wafer disposed in the test container to reach 30 particles.

(6) Test results Table 5 shows the test results. As is clear from this result, the oxide film (No. 1, 3, 5) of the comparative example has the least amount of generation of particles in the CH-containing gas, and is slightly increased in the F-containing gas to reach the allowable value. There is a situation where becomes shorter. However, it has been found that the number of particles generated in an atmosphere in which F-containing gas and CH-containing gas are alternately repeated is further increased. This is considered to be because the oxide film on the surface of the oxide ceramic film is always in an unstable state and scattered due to the repetition of the oxidizing action of the fluorinated gas and the reducing action of the CH gas in the F-containing gas. In contrast, the fluoride film (No. 2, 4, 6) maintains a chemically stable state in the F-containing gas, the CH-containing gas, and the atmosphere in which these gases are alternately repeated, and generates particles. It is thought to have been suppressed. In addition, it is thought that the environmental pollution resistance is also improved in that many are smaller by about 1/5 to 1/10 than those of the fluoride film.

(Example 6)
In this example, the corrosion resistance of the fluoride spray coating formed by the method of the present invention to the halogen acid vapor was investigated.
(1) Substrate: SS400 steel substrate (dimensions: width 30 mm × length 50 mm × thickness 3.2 mm) was used, and the surface was blast roughened and preheated to 180 ° C. to form a film.
(2) Thermal spray atmosphere: Ar gas heated to 850 ° C. was used as the working gas for film formation, and the flying speed of fluoride particles flying in this thermal spray atmosphere was 680 to 720 m / sec. Controlled to the range.
(3) Fluoride for film formation: A fluoride formed to a thickness of 250 μm using AlF ₃ , YF ₃ (particle size 10 to 60 μm) was prepared.
(4) Corrosion test (a) Corrosion test with HCl vapor is carried out by adding 100 ml of 30% HCl aqueous solution to the bottom of a dish for chemical experiments and suspending a test piece on the top to generate HCl generated from an aqueous HCl system. The method of exposure to vapor was adopted. The corrosion test temperature is 30 ° C. to 50 ° C., and the time is 96 hours.
(B) In the corrosion test with HF vapor, 100 ml of an HF aqueous solution was placed at the bottom of an SUS316 autoclave, and a test piece was hung on the top to suspend the corrosion test with HF vapor. The corrosion test temperature is 30 ° C. to 50 ° C., and the exposure time is 96 hours.

(6) Test results The test results are shown in Table 6. As is clear from the results shown in the table, all of the oxide-based films (Nos. 2 and 4) of the comparative examples had a large amount of red rust reaching the film surface. That is, since there are many through pores in the oxide-based film, vapors such as HCl and HF reach the inside of the film through the through holes and corrode the SS400 steel base material. It is considered that the iron component of the iron reached the surface of the coating through the through pores and exhibited a red rust shape. On the other hand, in the fluoride films (Nos. 1 and 3), although the occurrence of red rust was observed, the degree was only about 30 to 40% of the comparative example. From these results, there are through-pores in the fluoride film, but there are few compared to the oxide film, and the fluoride film itself has excellent corrosion resistance. It seems to have demonstrated good corrosion resistance.

(Example 7)
In this example, the influence of the pretreatment of the substrate surface on the adhesion of the fluoride spray coating was investigated.
(1) Kind of pretreatment The following pretreatment was performed on one side of an Al3003 alloy (dimension: diameter 25 mm x thickness 5 mm) as a base material.
(i) After degreasing, lightly polish with a wire brush.
(ii) After degreasing, a film with a thickness of 50 μm is formed from Ni-20 mass% Cr by atmospheric plasma spraying (metal undercoat)
(iii) After degreasing, WC-12 mass% Co is formed by a high-speed flame spraying method to form sparse sprayed particle interspersed areas (area ratio 22%)
(iv) After degreasing, a blast roughening treatment is performed using an Al ₂ O ₃ abrasive.
(v) On the same blasted surface as above, a film with a thickness of 80 μm was formed by atmospheric plasma spraying of Ni-20mass% Cr (metal undercoat)
(vi) On the blasted surface as above, WC-12mass% Co is formed by a high-speed flame spraying method to form scattered forested sprayed particle interspersed areas (area ratio 18%)
The above (iii) and (vi) are examples of the present invention, and the other (i), (ii), (iv) and (v) are comparative examples.

(2) Formation of fluoride spray coating The substrate surface after the pretreatment was heated to 800 ° C. and He gas was used, and the flying speed of fluoride particles flying through the surface was 680 to 750 m / sec. A fluoride sprayed coating with a film thickness of 140 μm was formed with YF ₃ particles controlled in the above range.

(3) Adhesion test method The adhesion of the thermal spray coating was measured by the adhesion strength test method defined in the JIS H8666 ceramic thermal spray coating test method.

(4) Test results Table 7 shows the test results. As is apparent from the results shown in this table, the fluoride sprayed coating (No. 1) formed on the light wire brushed surface after degreasing the substrate surface has poor adhesion and is 0.5 to 1.2 MPa. In the fluoride sprayed coating (No. 2) having a peeled coating and a metal undercoat, a slight improvement in adhesion is observed. On the other hand, the fluoride sprayed coating (No. 3) formed on the surface where WC-12 mass% Co is scattered sparsely exhibited a high adhesion of 13 to 16 MPa. On the other hand, the adhesion of the fluoride spray coating (No. 4) formed on the blast roughened surface is 4 to 6 MPa, and the fluoride spray sprayed with a metallic undercoat on the blast roughened surface. The adhesion of the film was No. 1, no. Compared with the case of 2, it tends to be higher, and the roughening of the base material and the construction of the metallic undercoat are effective in improving the adhesion of the film. On the other hand, the surface (No. 6) having the sprayed particle interspersed portion formed by spraying the carbide cermet particles according to the present invention further improves the adhesion with the fluoride sprayed coating. A high adhesion of 15 MPa was exhibited.

As described above, the fluoride film obtained by thermal spraying using the inert gas as a working fluid at a relatively low temperature to an ultrahigh speed according to the present invention can be obtained by thermally decomposing fluoride particles for film formation or removing F _{Since the two-} component phenomenon does not occur, the formed fluoride film exhibits the original physicochemical properties of fluoride. Furthermore, during film formation, a hard carbide cermet particle is sprayed on the side of the substrate that collides with large kinetic energy in addition to preheating so that it becomes a spotted state, and the roughened surface treatment uses the pierced particle as a projection. Thus, it is possible to form a fluoride sprayed coating that is dense and has high adhesion. The fluoride spray coating formed in this way is physicochemical, such as acid resistance, halogen gas resistance, plasma erosion resistance, etc., compared with coatings formed by conventional plasma spraying and high-speed flame spraying methods. It is excellent in properties and can be expected to be used in fields where more stringent and superior performance is required as a coating for general petrochemical and chemical plants as well as the coating for current semiconductor processing equipment members.

DESCRIPTION OF SYMBOLS 1 Working gas source 2 Spraying material supply device 3 Gas heating heat exchanger 4 Spraying vessel 5 Spray gun 6 Nozzle 7 Processed object 8 Silencer 9 Main gas pipe 10 Sub gas pipe 11 Working gas rectifying plates 12, 13 valve

Claims (14)

First, the surface of the base material is pretreated, and a carbide cermet material is sprayed onto the surface of the base material after the pretreatment, and the tip portion of at least a part of the sprayed particles of the carbide cermet is 8 to 50% in terms of area ratio. Therefore, a non-film-like sprayed particle interspersed portion of carbide cermet adhered to the base material surface in a sparsely attached state in which the tip of the sprayed particle stabs like a pile on the surface of the base material is formed. Prior to spraying the spray material, the surface of the base material and the sprayed particles of the carbide cermet are preheated to a temperature of 80 to 700 ° C., and then the base material surface and the sprayed particles of the carbide cermet are scattered. On the part, a thermal spray gun using an inert gas such as Ar, N ₂ , He or a mixed gas thereof as a film forming working gas is maintained at a temperature of 600 ° C. to 1300 ° C. Thermal spray atmosphere In the middle, flight speed: 500m / sec. Spraying at the above speed, the sprayed particles of fluoride are made to penetrate into the gaps between the sprayed particles of the carbide cermet sprayed particles and adhere to the surface of the base material to coat it. Method for forming a film.   The sprayed particle interspersed portion of the carbide cermet has a flight speed of 150 to 600 m / sec. The method for forming a fluoride sprayed coating according to claim 1, wherein the spraying is performed at a spraying speed of   After the roughening treatment of the substrate surface, the carbide cermet material was supplied to the spray gun at a rate of 100 to 200 g / min. When the spray gun repeatedly moves on the substrate surface, the moving speed is set to 300 to 1000 mm / sec. The sprayed particle interspersed portion of the carbide cermet consisting of a portion of 8 to 50% in area ratio is formed by performing a spray gun operation with the number of sprays of 5 times or less under the conditions controlled in the above. The method for forming a fluoride sprayed coating according to claim 1 or 2.   3. The method for forming a fluoride sprayed coating according to claim 1, wherein the pretreatment is at least one of degreasing, descaling, and surface roughening treatment. In the roughening treatment, the surface roughness is set to Ra: 0.05 to 0.74 μm and Rz: 0.09 to 2.0 μm by roughening treatment in which an abrasive such as Al ₂ O ₃ or SiC is sprayed. The method for forming a fluoride sprayed coating according to claim 4.   The base material is any one of Al and its alloys, Ti and its alloys, carbon-containing steel, various stainless steels, Ni and its alloys, oxides, nitrides, carbides, silicides, and carbon sintered bodies. The method for forming a fluoride sprayed coating according to any one of claims 1 to 5. The carbide cermet material is at least one selected from WC—Co, WC—Ni—Cr, WC—Co—Cr, Cr ₃ C ₂ —Ni—Cr, and the like. The method for forming a fluoride sprayed coating according to any one of the above.   The fluoride spray coating is composed of Mg of periodic table group IIa, Al of group IIIb of periodic table, Group IIIa group Y of periodic table, lanthanum (La), cerium (Ce) which is a lanthanoid metal of atomic number 57-71. , Praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), eurobium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er) One or more fluoride particles having a particle size of 5 μm to 80 μm selected from fluorides of thulium (Tm), ytterbium (Yb), and lutetium (Lu) were sprayed to form a film thickness of 20 μm to 500 μm. The method for forming a fluoride sprayed coating according to any one of claims 1 to 7, wherein the method is a method.   9. The interval between the tip of the spray nozzle for injecting fluoride particles and the substrate surface is maintained at 5 to 50 mm by a spraying method using an inert gas as a working gas for film formation. The method for forming a fluoride sprayed coating according to any one of the above.   The method for forming a fluoride sprayed coating according to any one of claims 1 to 9, wherein the fluoride sprayed coating has a thickness of 20 to 500 µm. Comprising a base material and a fluoride spray coating coated on the substrate surface,
The substrate has an area of 8 to 50% of the surface of one or more carbide cermets selected from WC—Co, WC—Ni—Cr, WC—Co—Cr and Cr ₃ C ₂ —Ni—Cr. It is covered with non-film-like sprayed particles ,
At least a part of the sprayed particle interspersed part is formed by sparsely depositing carbide cermet sprayed particles on the surface of the base material , and the other part is composed of carbide cermet sprayed particles on the base material surface. Is attached or buried in the substrate , and
The fluoride thermal spray coating, fluoride sprayed coating covering member characterized by those which are formed to cover the substrate from above the Katsuso through the spray particles interspersed section. 12. The fluoride sprayed coating according to claim 11, wherein the substrate has a rough surface with a surface roughness of Ra: 0.05 to 0.74 [mu] m, Rz: 0.09 to 2.0 [mu] m. Element.   The base material is any one of Al and its alloys, Ti and its alloys, carbon-containing steel, various stainless steels, Ni and its alloys, oxides, nitrides, carbides, silicides, and carbon sintered bodies. The fluoride sprayed coating-coated member according to claim 11 or 12, wherein: The fluoride spray coating is a lanthanum metal having a film thickness of 20 μm to 500 μm, a lanthanoid metal of Group IIa of Mg, Group Al of Group IIIb, Group IIIa of Periodic Table Y, and atomic number 57-71. (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Eurobium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), any claim from 11 to 1 3, characterized in that the coating contains at least one element selected from the fluorides of lutetium (Lu) The fluoride sprayed coating covering member according to claim 1.

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