TWI385277B - Preparation method of black yttrium oxide sputtering film and black yttrium oxide sputtering film coating material - Google Patents

Description

Method for forming black yttria spray film and black yttrium oxide spray film coating material

The present invention relates to a method for forming a black cerium oxide spray film having excellent properties such as heat radiation resistance and damage resistance, and a black yttria spray coating material having excellent color pattern properties.

The spraying method is a technique in which a powder such as a metal or a ceramic or a cermet is melted by a plasma jet or a combustion flame, and is blown onto the surface of the object to be irradiated (substrate) to form a film on the surface of the substrate. One of the surface treatment technologies is widely used in most industrial fields. The spray film obtained by the above-described spray method is known to have mechanical strength or corrosion resistance in the film due to the strong bonding force between the particles of the film, the amount of unbound particles, and the amount of unmelted particles (hereinafter referred to as "unmelted particles"). There is a huge difference in it.

For this reason, the development goal of the conventional melting technology is, for example, by using a high-temperature heat source in the plasma to generate strong impact energy on the surface of the fused body, thereby improving the bonding force between the particles while reducing the porosity and even raising the film. The adhesion between the substrate and the substrate.

On the other hand, the molten metal film is formed in the atmosphere, and all of the molten particles are in contact with air, and an oxide film is formed on the surface of the particles, and the adhesion between the particles and the substrate is deteriorated in view of the decrease in the bonding force between the particles. A method for solving this problem is, for example, a method of performing melting in a low-pressure inert gas atmosphere (generally referred to as a reduced-pressure plasma spraying method) as proposed in Japanese Laid-Open Patent Publication No. Hei No. Hei. Specifically, in a vacuum container that discharges air In the case, argon gas is introduced at 50 hectopascals (hPa) to 200 hectopascals to perform plasma spraying in the atmosphere.

In this regard, the molten film of the oxide-based ceramics is oxidized by the powder itself, so that it is not oxidized in the atmosphere, and on the other hand, it is melted in an argon atmosphere under reduced pressure. The shot also does not undergo chemical changes on the molten particles. Since then, the current state of the oxide ceramic decompression plasma spray method is a case of less research and development on atmospheric plasma spray.

Further, studies on conventional spray coatings have been made of metals (alloys), ceramics, cermets, etc. due to the improvement in hardness, wear resistance, heat resistance, corrosion resistance, or adhesion of the film. The type of molten material and the chemical composition are selected, and placed in a key position in the selection of the spray method and the determination of the spray conditions. Therefore, for the conventional spray film, there is almost no research work to utilize the color of the film to enhance the commercial value of the color pattern of the spray film product.

However, observing the appearance color of the ceramic molten film, it was found that the chromium oxide (Cr ₂ O ₃ ) powder as a molten material is a dark green ink, and when it is sprayed, it becomes a black film. On the other hand, the alumina (Al ₂ O ₃ ) powder is white, and the film obtained by plasma spraying is also white. However, although the titanium oxide (TiO ₂ ) powder is white, it is a black film obtained by plasma spraying. In the foregoing, the reason for the color change of the molten film is that the molten heat source is, for example, a part of oxygen which constitutes titanium oxide disappears and becomes an oxide of (Ti _n O _2n-1 ). (Japanese Patent Laid-Open No. Hei 9-069554)

In the above description, after the oxide-based ceramic spray film is removed from a part of the oxide, the color of the powder material for the spray itself is originally reproduced only as the color of the film. For example, yttrium oxide (Y ₂ O ₃ ) is usually the same as alumina (Al ₂ O ₃ ), and is white in the state of a powder material, and the molten film obtained by spraying the powder material is also white. The cerium oxide is, for example, sprayed in a plasma heat source, and the enthalpy and oxygen-bonding state constituting the cerium oxide particles may not change. The chemical affinity of aluminum or bismuth as a metal element is also extremely strong, and oxygen does not disappear in a high-temperature plasma environment. Therefore, after the molten film is formed, the alumina and yttrium oxide can be maintained while maintaining the powder material. Physical and chemical properties.

The above-mentioned cerium oxide sprayed film is excellent not only in heat resistance, high temperature oxidation resistance, and corrosion resistance, but also is excellent in resistance to plasma etching in the plasma etching atmosphere by using a low temperature plasma of a halide. (Japanese Patent Laid-Open No. Hei 10-004083, Japanese Patent Publication No. Hei 10-163180, Japanese Patent Laid-Open No. Hei 10-547744, Japanese Patent Laid-Open No. Hei No. 2001-164354, Japanese Patent Laid-Open No. 2003-321760 Bulletin).

The cerium oxide spray film disclosed in the above documents is all white. Further, in the above document, since the characteristics of the white yttrium oxide film do not change, the color of the film is not changed, and it is used for the improvement of the product value of engineering and color patterns.

As a technique for modifying the surface of the substrate, in addition to coating the above-mentioned molten film, there is also a technique of irradiating with an electron beam or a laser beam. For example, in Japanese Laid-Open Patent Publication No. SHO 61-104062, the entire disclosure of the present invention is directed to a technique of illuminating a metal film on a metal film to melt the film to eliminate pores. Further, Japanese Laid-Open Patent Publication No. Hei 9-316624 discloses a technique of irradiating an electron beam to a carbide cermet film or a metal film to improve the film performance. Further, Japanese Laid-Open Patent Publication No. Hei 10-202782 discloses a technique of irradiating a zirconia (ZrO ₂ )-based ceramic spray film with a laser beam. In the case of forming a rare earth oxide sprayed film, a technique of adding carbon, titanium, and molybdenum to a molten material to change the film to gray to black is disclosed in Japanese Laid-Open Patent Publication No. 2004-100039. .

However, in the technique disclosed above, since it is necessary to add a heterogeneous component to the molten powder material, the addition work is increased, and the physicochemical property is lowered due to a decrease in the purity of the film component.

In short, the foregoing prior art is a technique for the purpose of eliminating the pores in the molten film, improving the adhesion, or performing longitudinal cutting on the film for the cooling process after remelting, without being added to the other components. A method of changing the appearance color of the spray film is proposed.

In contrast to the current state of the art, the inventors have disclosed in Japanese Patent Laid-Open Publication No. 2006-118053 that a white yttrium oxide sprayed film is successfully borrowed by irradiating a laser beam or an electron beam to successfully change it into black. The blackening of the spray film enhances the commercial value of heat radiation and color patterns.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for directly forming a yttria black molten film by spraying, without using a laser beam or an electron beam, using a molten material composed of white cerium oxide powder. By this method, the following problems possessed by the prior art can be solved.

(1) In the conventional technique, when a rare earth oxide film is colored, since a coloring component such as carbon, titanium, or molybdenum is added to the powder, the production process is not only increased, but also the cost is increased. The physicochemical properties such as reduction in film purity, corrosion resistance, and heat resistance are deteriorated by mixing other components.

(2) In the prior art, the blackening treatment of the yttria-sprayed film is performed by irradiating a laser beam or an electron beam to the surface of the film after forming a white yttrium oxide film, so it is necessary to use it for this purpose. Equipment, resulting in reduced productivity and increased production costs.

In order to solve the above problems possessed by the prior art, the present invention employs the following solutions.

The invention provides a method for forming a black cerium oxide molten film, which is a mixed gas of inert gas and hydrogen as a plasma. The operating gas for jet generation is used, and the white cerium oxide powder is sprayed with the plasma to form a yttria black molten film.

Further, in the present invention, it is preferred to give the following solution.

(1) The molten atmosphere for the flight of the molten material is maintained in a reduced pressure environment of 50 to 600 hectopascals by an inert gas.

(2) The foregoing yttria black molten film is formed by the aforementioned plasma. The reductive action of the atomic hydrogen contained in the jet is formed by stacking black particles of Y ₂ O _3-x in a state in which part of the oxygen of the yttria (Y ₂ O ₃ ) powder disappears.

(3) The spray atmosphere is to flow non-oxidizing gas around the plasma spray gun so that the air cannot invade the plasma toward the coated surface. The environment of the jet.

(4) The particle size of the molten material composed of the aforementioned white cerium oxide powder is 5 Micron to 80 microns.

(5) used to generate plasma. Among the above-mentioned operating gases to be injected, a gas having a volume ratio of inert gas to hydrogen of 10/1 to 3/1 is used.

(6) The foregoing cerium oxide black molten film is formed directly or by a primer on the surface of the substrate.

(7) The foregoing substrate is selected from various steels containing stainless steel, aluminum and alloys thereof, titanium and alloys thereof, tungsten and its alloys, molybdenum and its alloys, sintered carbon, quartz, glass, plastics, oxides and non-oxidation. One or more metal-based or non-metal-based substrates in the group of the ceramic sintered body.

(8) The primer is one or more metals selected from the group consisting of nickel and its alloys, chromium and alloys thereof, tungsten and alloys thereof, molybdenum and alloys thereof, titanium and alloys thereof, aluminum and alloys thereof, and alloys thereof.

Further, the present invention provides a black cerium oxide spray coating material which is formed by a thickness of 50 μm to 2000 μm of a yttria black melt film composed of Y ₂ O _3-x formed by the above method. .

In the present invention, it is preferred to give the following solution.

(1) A primer having a film thickness of 50 μm to 500 μm is provided between the foregoing cerium oxide black spray film and the substrate.

(2) The foregoing substrate is selected from various steels containing stainless steel, aluminum and alloys thereof, titanium and alloys thereof, tungsten and its alloys, molybdenum and its alloys, sintered carbon, quartz, glass, plastics, oxides and non-oxidation. One or more metal-based or non-metal-based substrates in the group of the ceramic sintered body.

(3) The aforementioned primer is selected from the group consisting of nickel and its alloys, chromium and its alloys, tungsten and its alloys, molybdenum and its alloys, titanium and its alloys, aluminum and its alloys. More than one metal and its alloys.

(4) The spray atmosphere flows through the non-oxidizing gas around the plasma spray gun, so that the coated surface is prevented from facing the plasma. The environment in which the injected air invades.

(5) The particle size of the molten material composed of the aforementioned white cerium oxide powder is from 5 μm to 80 μm.

(6) used to generate plasma. Among the above-mentioned operating gases to be injected, a gas having a volume ratio of inert gas to hydrogen of 10/1 to 3/1 is used.

According to the present invention, the effects shown below can be expected.

(1) The present invention is used as a plasma of a heat source for spraying. In the inert gas for jet generation, by adding hydrogen which is highly reductive, it is possible to directly form black yttrium oxide by using a commercially available white yttrium oxide powder for spraying without using a coloring component such as carbon or titanium or molybdenum. Spray film. It is therefore possible to use only existing spray-related devices comprising a reduced-pressure plasma spray device.

(2) According to the present invention, since the processing for secondary blackening such as laser beam or electron beam irradiation can be omitted, a high-energy irradiation device or the like is not required. Therefore, economic effects such as improved workability and no need for new equipment will increase.

(3) In the method of forming a black cerium oxide film by an oxygen-free plasma spraying method under reduced pressure (Japanese Patent Laid-Open Publication No. Hei. No. 2006-118053), black which is doped from gray to black is present, and Unstable quality. According to the present invention, a constant and stable black cerium oxide film can be obtained, and quality improvement and productivity improvement can be obtained.

(4) The black cerium oxide spray film to which the method of the invention is applied has the same corrosion resistance and plasma resistance as the white yttria sprayed film. Aggressive, so Used for the same purpose.

(5) According to the present invention, since the molten film itself is black, the material of the black molten film is formed, which can be used as a heat transfer surface or a heat receiving surface, in addition to the heat absorption capability and the far infrared radiation capability. It can also improve heat radiation characteristics and heat efficiency. In particular, it is possible to achieve a uniform quality effect while being programmed into a semiconductor processing apparatus and increasing the speed of plasma etching.

(6) A product having a black yttrium oxide sprayed film formed according to the present invention, in order to maintain a black gloss in the entire thickness direction, for example, surface cutting machining can be performed to make the film black, thereby improving the quality of the product.

(7) When the black cerium oxide spray coating material of the present invention is used in a semiconductor processing apparatus, since the reaction product due to particles or etching does not adhere significantly, an additional cleaning device is not required to improve the operation efficiency.

(8) Used in semiconductor manufacturing. Among the molten film of the processing apparatus, the alumina ceramic is represented by a white color, and the cerium oxide molten film formed by a conventional technique is also white. For this reason, it is difficult to distinguish the material of the film during the conservative inspection. When it is damaged, the troublesome work is to prepare a lot of countermeasures. When the black cerium oxide is sprayed on the coating material, the difference in the material of the coating becomes easy, and the accuracy and productivity of the conservative inspection can be improved.

(9) According to the material of the present invention, an industrial product such as a semiconductor processing apparatus excellent in color pattern and high in commercial value can be obtained.

A method of forming a black cerium oxide sprayed film using a molten material composed of white yttria (Y ₂ O ₃ ) powder will be described.

In the present invention, in order to use a commercially available molten material composed of white yttrium oxide (Y ₂ O ₃ ) powder to form a black yttrium oxide sprayed film, the operation gas introduced as a heat source in the spray gun is not only An inert gas such as argon or helium is added to the operating gas to add a regenerative gas such as hydrogen. The flight path of the molten particles from the spray gun to the substrate must reduce the oxygen potential in the film forming (spraying) atmosphere.

Hereinafter, the reason why the black cerium oxide film is formed by the melt will be described. In general, the plasma spray operating gas uses an inert gas such as argon or helium. In the arc in the spray gun that is subjected to the DC voltage, the inert gas flows to produce a high temperature plasma. Spray as a heat source. This plasma. In the environment where the heat source is sprayed, it is composed of electrons, ions, atoms, and molecular combinations that are ionized from argon or helium. Therefore, as long as there is no air from the outside, it is reductive or non-oxidizing.

However, the plasma heat source in the spray gun in this state was supplied with white yttria (Y ₂ O ₃ ) powder and sprayed, and the obtained spray film was white, and the appearance color did not change. The reason is that plasma is usually used in plasma spraying. The jet is weaker, and since the molten atmosphere in which the molten particles fly is atmospheric, the yttria (Y ₂ O ₃ ) powder particles which are sprayed by the heat source and are in contact with the air are only in a white structure.

However, in the vacuum plasma spray method, the molten atmosphere gas, that is, the droplets ejected from the spray gun, flies toward the coated surface and the oxygen partial pressure in the spray environment is greatly reduced. Substantially oxygen-free argon forms a film under a reduced pressure of 50 hectopascals to 200 hectopascals, and sometimes changes to gray under weak oxidizing properties, but does not change to black.

For this reason, in the present invention, a. As the operation gas 4 introduced into the spray gun 2 provided in the decompression vessel 1, in addition to the conventional argon or helium, a hydrogen gas having a strong mixing property is introduced.

b. The spray gun 2 and the substrate to be treated 3 are disposed in the decompression vessel 1, that is, the spray atmosphere is maintained in an inert gas such as argon or helium.

In particular, in the operating gas system for plasma generation supplied to the spray gun 2 in the present invention, a mixed gas obtained by adding hydrogen as a regenerative gas is used. When this operating gas is used, the molten material (white yttrium oxide (Y ₂ O ₃ ) powder) which is introduced into the spray gun 2 can be simultaneously synchronized due to the presence of atomic hydrogen which exhibits strong reductivity during the plasma generation. 5 yuan. Moreover, the molten material that has been reduced is multiplied by the plasma. The spray 6 is applied to the surface of the substrate. The yttrium oxide sprayed film 7 formed therein is a black fused film formed by depositing reduced black yttrium oxide (Y ₂ O _3-x ) spray particles in the spray.

In this regard, the inventors found that the black yttrium oxide spray film is composed of particles of yttrium oxide (Y ₂ O _3-x ) which are formed by white yttria (Y ₂ O ₃ ) particles disappearing from a part of oxygen atoms. The film. Here, the inventor's white cerium oxide is represented by "Y ₂ O ₃ ", and the "Y ₂ O _3-x " composition obtained according to the present invention is black cerium oxide, which is also called "cerium oxide". Also alumina (Al ₂ O ₃ ) uses the aforementioned plasma containing hydrogen. When the jet heat source is formed into a film, it also appears white, so the phenomenon of blackening of yttrium oxide (Y ₂ O ₃ ) is a peculiar phenomenon of the present invention.

According to the study by the inventors, when the mixed operating gas 4 to which the hydrogen gas is added as the plasma heat source in the inert gas of the spray gun 2, the flow path of the molten particles from the spray gun toward the surface to be treated (the surface of the substrate) is atmospheric. Medium time The atmosphere is contacted with air and returned to white or gray. Therefore, in the present invention, control of the spray atmosphere gas (particle flight path) is also important. That is, without using the decompression container 1, the atmospheric plasma is sprayed (the flight path is under the atmosphere), the aforementioned plasma. Spray 6 needs to be installed with air to prevent air from entering the environment, or plasma. Only an inert gas such as argon, helium or nitrogen or a gas having low reactivity is allowed to flow around the jet, and it is necessary to prevent the molten particles flying in a molten state from coming into direct contact with the air. Based on this, a vacuum plasma spray device which can form a film under a reduced pressure inert gas atmosphere is preferably used, and it is preferable that contact between particles and air (correctly, oxygen) does not occur during the flight.

Further, the amount of hydrogen added to the plasma generating gas such as argon or helium is preferably a mixing ratio of a volume such as the lower one. That is, argon/hydrogen = 10/1 to 3/1

The hydrogen mixing ratio is 10/1, preferably 5/1. When the ratio is less than 5/1, the blackening of the cerium oxide is incomplete and the color quality is not fixed. On the other hand, when argon is mixed more than 3/1, the blackening effect is saturated.

As the plasma generating gas, a mixed gas of argon and helium may be used, and the object of the invention can be attained by maintaining the ratio of the hydrogen gas to the argon gas alone. The above ratio is preferably from about 5/1 to about 3/1.

2(a) to (d) are graphs showing the appearance of a black yttrium oxide sprayed film formed in accordance with the teachings of the present invention and a Y ₂ O ₃ film obtained according to the prior art. It is apparent from this figure that an argon/hydrogen mixed gas suitable for the present invention is used as the plasma. The operating gas for jet generation is controlled even in a non-oxidizing atmosphere, and is sprayed under an atmosphere having a small partial pressure of oxygen to make formation of a black cerium oxide film.

(a) Use argon/hydrogen volume ratio = 4/1 as the plasma. The gas was generated by spraying, and white Y ₂ O ₃ (Monsell: N3, black or dark gray) was sprayed in an atmosphere of 200 kPa of argon gas.

(b) Use only argon as the plasma. A gas was generated by spraying, and white Y ₂ O ₃ (N5, bright gray) was sprayed in an atmosphere of 200 kPa of argon gas.

(c) Using the condition gas of (a), Y ₂ O ₃ (N4, medium gray) is sprayed while the argon gas in the atmosphere of the spray gun is in the atmosphere.

(d) Using a conditional gas of (b), white Y ₂ O ₃ (N9, white) is sprayed in the atmosphere.

Next, the powder size and purity of this powder will be described with respect to the present invention as a Y ₂ O ₃ powder for forming a black cerium oxide molten film material.

The Y ₂ O ₃ powder particle size is preferably in the range of 5 to 80 μm, more preferably 5 to 50 μm. The reason is that the powder having a particle diameter larger than 80 μm includes a plurality of unmelted particles that are not completely melted in the heat source for melting. Since the inside of the unmelted particles is not affected by the plasma heat source containing hydrogen, it is considered to be maintained in a white state, which is a factor that lowers the film quality. On the other hand, particles of 5 μm or less are completely melted and blackened to the inside, and the supply and supply speed from the powder supply machine to the spray gun is unstable, and the state is melted and raised in the plasma heat source, and cannot be used to constitute The strength factor of the film, so the profile of the sprayed film may be uneven, incomplete, and may deteriorate the film strength.

The purity of the cerium oxide powder used in the present invention is preferably such that impurities (e.g., iron, magnesium, chromium, aluminum, nickel, ruthenium, etc.) are less. Recently, the inventors investigated commercial products, all of which are above 98% by weight, even if this commercial form is used. It is preferred that the black cerium oxide film is formed, but the invention is not limited thereto.

Next, a substrate for forming a black cerium oxide sprayed film will be described. The object of forming the above-mentioned yttria black molten film in the present invention, that is, the substrate, is initially aluminum and its alloys, stainless steel, titanium and alloys thereof, and ceramic sintered bodies (for example, oxides, nitrides, borides, tellurides, and As the mixture of the above compounds, a material composed of quartz, glass, plastic or the like can also be used. Further, various vapor deposition films or coating films may be applied to such materials, or may be formed directly or via a primer or an intermediate layer on the surface of the material.

Next, the film structure of the black cerium oxide spray coating material will be described.

In the material of the present invention, in addition to directly coating the above-mentioned cerium oxide black molten film on the surface of the substrate, a primer may be formed on the surface of the substrate before forming the molten film, and then the black cerium oxide spray film is formed. As a surface coating to enhance the adhesion of the film. At this time, the primer material may use one or more metals selected from the group consisting of nickel and its alloys, chromium and its alloys, tungsten and its alloys, molybdenum and its alloys, titanium and its alloys, aluminum and its alloys, and magnesium alloys. ,alloy. Further, it is preferred to apply the primer to a thickness of about 50 μm to 500 μm.

In this case, when the primer spray film is thinner than 50 μm, the primer has a weak effect. On the other hand, when the thickness of the primer spray film exceeds 500 μm, the coating effect is saturated, and the production cost depending on the film forming operation may be increased.

Further, the primer is preferably an arc spray method, a flame spray method, a high-speed flame spray method, an atmospheric plasma spray method, a vacuum plasma spray method, or an explosion. Spraying method, etc.

On the other hand, the black cerium oxide molten film of the present invention which becomes a surface coating layer is preferably formed by directly forming a film on the surface of the substrate or by depositing a film on the primer. It is applied to 50 microns to 2000 microns. Thinner than 50 microns, corrosion resistance and plasma resistance. Insufficient erosion. On the other hand, a film thicker than 2000 microns is uneconomical because the effect is saturated.

The primer is formed as an intermediate layer between the black cerium oxide spray film and the substrate, and preferably the bonding strength between the substrate and the substrate is selected, and the other side is maintained with the black cerium oxide as the surface coating. Good adhesion. The material is preferably a metal material selected from the group consisting of nickel and its alloys, chromium and its alloys, tungsten and its alloys, molybdenum and its alloys, titanium and its alloys, aluminum and its alloys, and magnesium alloys. Metal, alloy. Further, it is preferred to apply the primer to a thickness of about 50 μm to 500 μm.

In this case, when the primer spray film is thinner than 50 μm, the primer has a weak effect. On the other hand, when the thickness of the primer spray film exceeds 500 μm, the coating effect is saturated, and the production cost depending on the film forming operation may be increased.

(Example 1)

In this embodiment, a Y ₂ O ₃ white spray film according to a conventional technique is formed on the surface of a quartz glass protective tube having a built-in heating wire, and a conventional technique (Japanese Patent Laid-Open Publication No. Hei. No. 2006-118053) After the white Y ₂ O ₃ molten film was irradiated with an electron beam to form a blackened film and the yttria black molten film (50 μm thick) of the present invention, a current was passed through the heating wire, and the wavelength emitted from each film was examined.

The results show that the Y ₂ O ₃ white spray film is about 0.2 μm to 1 μm, and the black film obtained by electron beam irradiation treatment and the present invention in the yttria black spray film is also 0.3 μm to 5 μm. It is determined that infrared radiation is emitted and the efficiency of the heater is different.

Further, in order to replace the quartz glass heater, the above two kinds of yttria black molten film (50 μm thick) are applied on the surface of a halogen lamp (high-brightness lamp), and the wavelength of the lamp is 0.2 to 0.4 μm with respect to the state without the film. Inside, the black spray film is applied from 0.3 μm to 10 μm in the far-infrared region that can be utilized, which can significantly improve the efficiency of the heater. There is also a Y ₂ O ₃ white spray film obtained according to the conventional technique, which is the same as or in the wavelength range below which the spray film is not applied.

From the above results, it can be seen that the black yttrium oxide spray film formed by the method of the present invention is not only resistant to plasma as a material for a semiconductor processing device. Erosive enhancement can also be useful as a heat source to promote the speed of etching processing.

(Example 2)

In this embodiment, after the surface of the test piece of SUS410 steel (50 mm × 50 mm × 5 mm) is subjected to bombardment roughening treatment, the argon gas is controlled to have an atmospheric gas pressure of 50 to 200 hPa. The piezoelectric slurry was sprayed to form 150 μm thick Y ₂ O ₃ . At this time, before the formation of the Y ₂ O ₃ film, whether or not a primer of 100 μm thick nickel-aluminum alloy was obtained by the atmospheric plasma spraying method on the test piece was examined to investigate the effect.

Further, when the vacuum film is sprayed, when the black film of the present invention is formed, A mixed gas having an argon/hydrogen volume ratio of 5/1 was used as the operating gas. Also in the case of the comparative example, a mixed gas having an argon/rhenium ratio of 5/1 was used.

The test piece on which the sprayed film was formed was subjected to the following thermal shock test after investigating the appearance color of the surface coating formed by the molten yttrium oxide (Y ₂ O ₃ ) to investigate the peeling resistance of the sprayed film.

Table 1 is a summary of the above results. From the results, it was found that the test piece (No. 1 to 4) formed in the film was black under the condition that the mixed gas having an argon/hydrogen volume ratio of 5/1 was used as the plasma heat source operating gas. The test pieces (No. 5 to 8) showed only gray but not black under a mixed gas condition of hydrogen/hydrogen-free argon/rhodium ratio of 5/1.

The test piece is first heated to 500 degrees Celsius and maintained in an electric furnace for about 15 minutes, then put into water of 25 degrees Celsius and repeated for 5 times, and directly forms yttrium oxide on the whole test film, that is, the substrate. ₂ O ₃ ) The spray film and the primer with nickel-aluminum alloy are not related to the appearance of the Y ₂ O ₃ spray film. Under the conditions of the examples, it was confirmed that all of the excellent thermal shock resistance can be exhibited, and the peeling resistance due to blackening can be lowered.

(Example 3)

In this embodiment, all of the spray test sheets shown in Example 2 were formed by an atmospheric plasma spray method, and the peeling resistance of the film was investigated by a thermal shock test under the same conditions as in Example 2. Also, in the atmospheric plasma spray method, while using an argon/hydrogen volume ratio of 4/1, the periphery of the spray gun, especially near the exit of the spray gun, flows a large amount of argon gas to prevent plasma. The injected air invades.

Table 2 shows this result. Whether the black yttrium oxide spray film is formed by the atmospheric spray method or the vacuum plasma spray method of the second embodiment, it can be the same as the white Y ₂ O ₃ spray film obtained by the conventional technique. And maintain excellent peel resistance.

(Example 4)

In this embodiment, an aluminum substrate of 50 mm × 50 mm × 5 mm thickness is used, which is sprayed by atmospheric plasma on the surface and uses a plasma composed of different compositions. The jet-generating operating gas was used as a source of the spray heat to form a 150 μm thick Y ₂ O ₃ spray film and an alumina spray film. At this time, the presence or absence of a nickel-aluminum alloy film (100 μm) as a primer was added to the test conditions. Thereafter, the surface area of the central portion of the test piece was exposed to a range of 10 mm × 10 mm, and the other portions of the mask were exposed, and a 20-hour plasma erosion test was carried out under the following conditions. Further, as another surface treatment method, an aluminum substrate was anodized (corrosion-resistant aluminum) as a comparative sample.

<plasma etching conditions>

Etching gas: carbon tetrafluoride (CF ₄ ), argon, oxygen (volume ratio of 10:100:1) Plasma output: 1300 watts.

The test results are shown in Table 3. As a result, it was apparent that the anodic oxide film (No. 10), the alumina spray film (No. 7, 8), and the boron carbide spray film (No. 9) obtained according to the prior art of the comparative example were used. Holding a plasma. The amount of erosion becomes large, and this lacks durability in the plasma environment.

On the other hand, the black cerium oxide molten film (No. 1 to 4) of the present invention can exhibit excellent plasma corrosion resistance regardless of the presence or absence of the primer. Further, under the same conditions, the molten film (No. 5 to 8) was compared with the white yttrium oxide (Y ₂ O ₃ ) to be tested, and it was confirmed that the sprayed film of the present invention can be used as the whole. Durability.

[Industry use possibility]

The technology of the present invention can be applied not only to black semiconductors, but also to other ceramics such as titanium dioxide and titanium dioxide-aluminum oxide, so that it can be applied to semiconductors, liquid crystals, other, polymer industries or machinery industries. Formed from the materials used.

1‧‧‧Decompression container (spraying environment)

2‧‧‧Solving gun

3‧‧‧Processed substrate

4‧‧‧Operating gas

5‧‧‧Solid material

6‧‧‧ Plasma. injection

7‧‧‧Oxide spray film

Figure 1 is a schematic circuit diagram showing a plasma spray gun.

Fig. 2 is a photomicrograph showing the appearance of a yttrium oxide spray film.

1‧‧‧Relief container

2‧‧‧Solving gun

3‧‧‧Processed substrate

4‧‧‧Operating gas

5‧‧‧Solid material

6‧‧‧ Plasma. injection

7‧‧‧Oxide spray film

Claims (9)

A method for forming a black cerium oxide molten film, characterized in that a mixed gas of an inert gas and hydrogen is used as a plasma. In a spray gun for generating an operating gas for injection, white Y ₂ O ₃ powder is supplied to generate a black Y ₂ O ₃ molten powder, and the black Y ₂ O ₃ molten powder is sprayed in an inert gas under reduced pressure atmosphere. The medium is jetted and sprayed by plasma to form a yttria black molten film on the surface of the substrate. The method for forming a black cerium oxide spray film according to claim 1, wherein the vacuum gas atmosphere for the inert gas of the molten material is maintained in a reduced pressure environment of 50 to 600 hectopascals. . The method for forming a black cerium oxide molten film according to claim 1 or 2, wherein the cerium oxide black molten film is formed by the foregoing plasma. The reductive action of the atomic hydrogen contained in the jet is formed by stacking black particles of Y ₂ O _3-x in a state where the partial oxygen of the Y ₂ O ₃ powder disappears. The method for forming a black cerium oxide sprayed film according to claim 1 or 2, wherein the spray atmosphere flows a non-oxidizing gas around the plasma spray gun so that the air cannot invade the coated surface. Injection of plasma. The environment of the jet. The method for forming a black cerium oxide sprayed film according to claim 1 or 2, wherein the powder of the above-mentioned white Y ₂ O ₃ powder has a particle diameter of 5 μm to 80 μm. The method for forming a black cerium oxide molten film according to claim 1 or 2, wherein the plasma is generated. In the above-mentioned operating gas sprayed, the volume ratio of the inert gas to the hydrogen gas is in the range of 10/1 to 3/1. gas. The method for forming a black cerium oxide spray film according to claim 1 or 2, wherein the cerium oxide black spray film is formed directly or via a primer on the surface of the substrate. The method for forming a black cerium oxide sprayed film according to claim 1 or 2, wherein the substrate is selected from the group consisting of various steels containing stainless steel, aluminum and alloys thereof, titanium and its alloys, tungsten and its alloys, molybdenum and alloys thereof. And one or more metal-based or non-metal-based substrates in the group consisting of sintered carbon, quartz, glass, plastic, oxide, and non-oxide ceramic sintered body. The method for forming a black cerium oxide sprayed film according to claim 7, wherein the primer is selected from the group consisting of nickel and its alloys, chromium and its alloys, tungsten and its alloys, molybdenum and its alloys, titanium and its alloys, and aluminum One or more metals and alloys thereof in the group of alloys.