JP2007314886A - Member coated with yttrium oxide sprayed coating film, excellent in heat-radiation property and damage resistance and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a black sprayed coating film of yttrium oxide on the surface of a substrate to solve the problem that the color of conventional Y<SB>2</SB>O<SB>3</SB>sprayed coating films is limited to white. <P>SOLUTION: A member coated with the yttrium oxide sprayed coating film is excellent in heat-radiation property and damage resistance, wherein the surface of the substrate is coated with the black sprayed coating comprising yttrium oxide represented by the formula: Y<SB>2</SB>O<SB>3-x</SB>. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plasma sprayed coating member having excellent thermal radiation and damage resistance, and a method for producing the same, by forming a blackened yttrium oxide layer on a substrate surface. .

  Thermal spraying can accelerate the process of melting metal, ceramics, cermet powder, etc. with plasma or combustion flame, and spray it onto the surface of the sprayed body (base material). This is one of the surface treatment techniques widely used in the industrial field. However, it is known that the thermal spray coating obtained by laminating fine particles in the molten state has a large difference in the mechanical strength and corrosion resistance of the coating depending on the strength of the particles constituting the coating and the presence or absence of the unbonded state. It has been. For this reason, the goal of conventional thermal spraying technology development is to apply a large kinetic energy to the thermal spray particles using a high-temperature heat source, for example, a device that aims to achieve complete melting of the thermal spray particles using plasma as a heat source or a high-speed combustion flame. Thus, by generating a strong collision energy on the surface of the sprayed object, an attempt was made to increase the bonding force between particles and minimize the porosity.

  For example, in Patent Document 1, by adopting a low-pressure plasma spraying method in which plasma spraying is performed in an argon atmosphere of 50 to 200 hPa, an oxide film generated on the particle surface, which is one of the causes of pore generation, is improved. We propose a method to reduce this.

Although the performance of the thermal spray coating has improved in recent years due to such technological development, there are not many examples that have examined the change in the color tone of the coating surface formed using the same thermal spray material. However, when the color of the ceramic sprayed coating is observed, the chromium oxide (Cr ₂ O ₃ ) powder as the sprayed material is dark green close to black, but when this is plasma sprayed, it becomes a black coating. On the other hand, the aluminum oxide (Al ₂ O ₃ ) powder is pure white, and the film obtained by plasma spraying this powder is white. However, titanium oxide (TiO ₂ ) powder is white, but when it is plasma sprayed, it becomes a black film. It is thought that the cause of such a color change is that, for example, a part of oxygen constituting TiO ₂ disappears in the thermal spray heat source and becomes an oxide that can be displayed with Ti _n O _2n-1. (See Patent Document 2).

As described above, the color of the oxide-based ceramic sprayed coating is generally one in which the color of the thermal spray powder material itself is reproduced as it is. For example, in the case of yttrium oxide (Y ₂ O ₃ ), as in the case of Al ₂ O ₃ , not only the state of the powder material but also the thermal spray coating obtained by thermal spraying this powder material is also a white system, It seems that the Y ₂ O ₃ bonding state does not change even when sprayed in a heat source. Both Al and Y as metal elements have extremely strong chemical affinity with oxygen, and even in a high temperature plasma environment, oxygen does not disappear and even after forming a sprayed coating, Al ₂ O in the powder material. ₃ because it is considered that the characteristics of Y ₂ O ₃ are maintained.

The Y ₂ O ₃ sprayed coating has excellent heat resistance, high-temperature oxidation resistance, and corrosion resistance, and excellent resistance (plasma erosion resistance) even in a plasma atmosphere used in semiconductor manufacturing equipment and processing processes. This is a ceramic film used in many industrial fields (Patent Documents 3 to 7).

All of the Y ₂ O ₃ sprayed coatings currently in use are white, and some effects have been recognized, but without changing the properties of the Y ₂ O ₃ sprayed coating, There are no proposals for technologies that change color. For example, if blackening of the Y ₂ O ₃ sprayed coating is possible, even if mechanical processing such as surface grinding is performed, a predetermined gloss (so-called black glow) can be imparted, and the commercial value is increased. Will be able to. Moreover, the black film is less noticeable than the white film, and is useful for reducing the number of cleaning of the film-coated member that causes a decrease in productivity. In addition, the black film is excellent in heat absorption ability and far infrared radiation ability, and can be expected to be industrially used to improve performance of heat exchange members such as heat receiving heat and to provide environment resistance. Nevertheless, the actual situation is that the blackening technology of the Y ₂ O ₃ sprayed coating has not been developed at present.
Japanese Patent Laid-Open No. 1-139749 JP 2000-054802 A JP-A-6-196421 JP-A-10-004083 JP 10-163180 A JP-A-10-547744 JP 2001-164354 A

  Next, as a technique for modifying the surface of the substrate, there is a technique using electron beam irradiation or laser beam irradiation in addition to the above-mentioned coating formation of the sprayed coating. For example, with respect to electron beam irradiation, Patent Document 8 discloses a technique for irradiating a metal film with an electron beam to melt the film and extinguish it. Patent Document 9 discloses a technique for applying electrons to a carbide cermet film or a metal film. There is a technique for improving the performance of a film by irradiating a beam.

However, all of these prior arts are directed to carbide cermets and metal films, and are techniques aimed at eliminating pores in the film and improving adhesion, and ceramics, particularly Y It is not a technique for adjusting the color of ₂ O ₃ sprayed coating.
As described in paragraph [0011] of Patent Document 9, these prior arts have a fixed idea that an electrically conductive coating is necessary to perform a thermal spray material by electron beam treatment. It is thought that it is caused. On the other hand, Patent Documents 10 and 11 can be exemplified for the technique of irradiating the thermal spray coating with a laser beam. However, in these exemplary techniques, there are many examples of irradiation not only on metal films but also on ceramic films such as carbide cermets. However, even if the base is a ceramic film, the purpose of the treatment is to eliminate the pores of the film and to promote the occurrence of vertical cracks associated with the remelting phenomenon of the film. The target ceramic film is a ZrO ₂ type.
Japanese Patent Laid-Open No. 61-104062 JP 9-316624 A Japanese Patent Laid-Open No. 9-327779 Japanese Patent Laid-Open No. 10-202782

An object of the present invention is to make it possible to solve the above-described problems of the prior art. In other words, in view of the fact that all conventional Y ₂ O ₃ sprayed coatings are limited to white, we propose a technology that breaks this reality and forms a black yttrium oxide sprayed coating on the substrate surface. There is to do.

This is because the following technical problems that cannot be solved by the white sprayed Y ₂ O ₃ coating can be solved by forming the black sprayed yttrium oxide sprayed coating.
(1) Y ₂ O ₃ white sprayed coating is blackened without impairing the properties of the coating, and can be used for the same applications as white coating (good use) sex).
(2) Since the color of the film is black, the film product is hardly contaminated, and it is not necessary to repeat washing more than necessary (environmental deterioration resistance).
(3) Since the color of the film is black, forming this film on the heat-dissipating surface and heat-receiving surface protects these members from the environment and improves the thermal emissivity and heat-receiving efficiency, thereby improving the overall performance of the device. Can contribute (good heat radiation characteristics).
(4) Since the sprayed coating of blackened yttrium oxide has a higher hardness than the white coating, it can also contribute to an improvement in wear resistance (damage resistance).

Therefore, in the present invention, in order to obtain a member coated with the yttrium oxide sprayed coating exhibiting the above-mentioned characteristics by color change, a black sprayed coating of yttrium oxide was formed as the sprayed coating formed on the surface of the substrate. There is a feature in the point. That is, technical matters characterized by the present invention are summarized as follows.
(1) An yttrium oxide sprayed coating excellent in thermal radiation and damage resistance, characterized in that the surface of the substrate is coated with a black sprayed coating made of yttrium oxide whose compound form is Y ₂ O _3-x Covering member.
(2) An yttrium oxide sprayed coating member characterized in that an undercoat made of a metal coating is provided under a black sprayed coating of yttrium oxide.
(3) An yttrium oxide sprayed coating member comprising an intermediate layer provided between an undercoat made of a metal coating and a black sprayed coating of yttrium oxide formed as a topcoat.
(4) The undercoat is one or more metals selected from Ni and alloys thereof, W and alloys thereof, Mo and alloys thereof, Ti and alloys thereof, Al and alloys thereof, and Mg alloys or alloys thereof. An yttrium oxide sprayed coating member characterized by being a metal coating formed with a thickness of 50 to 500 μm.
(5) The yttrium oxide sprayed coating member characterized in that the intermediate layer is formed by a coating of a solid solution or a mixture with Al ₂ O ₃ or Y ₂ O ₃ .
(6) The black sprayed coating composed of the above yttrium oxide is made of blackened yttrium oxide in which the outer periphery or the inside of each Y ₂ O ₃ particle constituting the coating takes the form of Y ₂ O _3-x . An yttrium oxide spray-coated member having a thickness of about 50 to 2000 μm by a laminate of particles having a layer.

The blackened yttrium oxide sprayed coating is produced by the method described below.
(1) Plasma spraying a white Y ₂ O ₃ powder material directly or on an undercoat applied to the surface of the substrate in an inert gas atmosphere not containing oxygen. To form a blackened layer of yttrium oxide in the form of Y ₂ O _{3 -x} .
(2) to the surface of the substrate, first, a white spray coating Y ₂ O _3, followed by laser beam irradiation, the form of the compound in the surface layer of white spray coating the Y ₂ O ₃ is Y A method of forming a blackened yttrium oxide layer that is ₂ O _3-x .
(3) A white sprayed coating of Y ₂ O ₃ is first formed on the surface of the substrate directly or on the undercoat applied to the surface of the substrate, and then in an inert gas atmosphere under reduced pressure. A method of forming a black yttrium oxide layer having a compound form of Y ₂ O _{3 -x} on a surface layer portion of the Y ₂ O ₃ white sprayed coating by electron beam irradiation.

As described above, the yttrium oxide blackened thermal spray coating, which is a structure unique to the present invention, basically has the various characteristics of the conventional Y ₂ O ₃ white thermal spray coating. Therefore, even in an environment such as plasma treatment in an atmosphere containing a halogen or a halogen compound, which is the main application of this thermal spray coating, it exhibits a performance equal to or higher than that of the white Y ₂ O ₃ thermal spray coating. In addition, when a black sprayed coating of yttrium oxide is formed on the heat transfer surface and the heat receiving surface, it exhibits superior characteristics in both heat radiation and heat receiving efficiency compared to the white Y ₂ O ₃ sprayed coating, such as plasma etching processing. Increase efficiency further.

  In addition, since the surface is a black coating (layer), contamination due to adhesion of particles flying from the handling process and the environment is inconspicuous, and the current number of cleanings that are repeated more than necessary can be reduced, so In addition to reducing the amount of maintenance and inspection, it can also contribute to improving production efficiency, reducing product costs, and extending the service life of equipment members due to cleaning with highly corrosive chemicals.

(1) Properties and Characteristics of Blackened Yttrium Oxide Sprayed Coating (Yttrium Oxide Black Sprayed Coating) The yttrium oxide black sprayed coating, which is a composition unique to the present invention, is at least the appearance of the Y ₂ O ₃ white sprayed coating. Although the difference is clearly different, X-ray diffraction of this blackened Y ₂ O ₃ sprayed coating does not reveal a clear difference in X-ray diffraction from the Y ₂ O ₃ white sprayed coating. It is considered the same. However, as shown in FIG. 1 (photograph), there is a clear difference in appearance. In the present invention, “blackened yttrium oxide sprayed coating” is referred to as a black sprayed coating of yttrium oxide. According to the experiments conducted by the inventors, the blackening phenomenon of the yttrium oxide sprayed coating becomes apparent when heated to a temperature higher than the melting point (rapid heating) for a short time in an environment with a low oxygen partial pressure. From this, it is presumed that a part of oxygen constituting yttrium oxide is lost, so that the form of the compound is considered to be Y ₂ O _3-x .

The black sprayed yttrium oxide, that is, the black sprayed yttrium oxide in the form of Y ₂ O _3-x , is compared with the properties of the white sprayed yttrium oxide spray formed by the atmospheric plasma spraying method. Differences are observed.
(i) Y ₂ O _{3-x type} black spray coating (it is a black spray coating of yttrium oxide, and the following notation is the same) The surface of the coating is very smooth and has good gloss. Value is improved.
(ii) Yttrium oxide black spray coating is less noticeable of dirt (for example, fingerprints, fine black dust etc.) than white spray coating, so maintenance management is easy and productivity is improved. .
(iii) Since the surface of the black sprayed coating of yttrium oxide is dense, the invasion of corrosive gas components into the coating is suppressed, and the corrosion resistance to the substrate is improved.
(iv) The surface of the yttrium oxide black sprayed coating is compared to the white sprayed yttrium oxide coating formed by atmospheric plasma spraying or low-pressure plasma spraying by melting each Y ₂ O _3-x particle constituting the coating. Thus, the mutual bonding force of the particles is remarkably improved, so that the hardness and wear resistance are improved.
(v) The phenomenon (iii) and (iv) described above is a Y ₂ O _3-x sprayed coating in which at least a depth of 30 μm from the surface layer is blackened among the black sprayed coating of yttrium oxide. In this case, the other part of the so-called yttrium oxide white sprayed coating maintains a porous state peculiar to the plasma sprayed coating. Accordingly, the black sprayed coating (layer) of yttrium oxide does not break or peel off even if the environment undergoes a rapid temperature change, that is, thermal shock.
(vi) When a black sprayed coating of yttrium oxide is formed on the surface of the heating element, a remarkable far-infrared radiation effect is exerted. Therefore, when it is disposed in a reduced pressure atmosphere, it is useful as a radiation heat source coating. In the case of this application, the effect is exhibited as the film thickness is thinner.
(vii) The physicochemical properties of the black spray coating of yttrium oxide are the same as the conventional Y ₂ O ₃ white spray coating except for the change in color tone (black change). Can be used for For example, one of the main uses of the Y ₂ O ₃ white spray coating is a member disposed in a plasma processing vessel related to a semiconductor manufacturing apparatus. In general, it is known that a thermal spray coating of yttrium oxide exhibits excellent plasma erosion resistance in an environment where plasma treatment is performed in an atmosphere containing various halogen gases. Black sprayed coating also shows outstanding performance.

Specifically, CF ₄
In 100cm ³ -Ar1000cm ³ -O ₂ 10cm mixed gas of ^3, where under the conditions of the plasma irradiation output 1300 W, was 20 hours irradiation experiments,
Erosion loss depth on the surface of the white Y ₂ O ₃ sprayed coating: 6.1 to 7.6 μm
Erosion loss depth on the surface of yttrium oxide black spray coating: 5.8-6.5μm
As a result, it was found that the black sprayed coating of yttrium oxide, which is peculiar to the present invention, has better plasma irradiation resistance.
Further, even when the white and black yttrium oxide sprayed coatings were immersed in a 2N NaOH aqueous solution (40 ° C.), both coatings were not eroded at all and exhibited excellent alkali resistance.

  In the present invention, in forming the black sprayed coating of yttrium oxide on the substrate surface, an undercoat may be first formed on the substrate surface. In this case, the undercoat material is one or more metals or alloys selected from Ni and alloys thereof, W and alloys thereof, Mo and alloys thereof, Ti and alloys thereof, Al and alloys thereof, Mg alloys, and the like. It is preferable to apply to a thickness of about 50 to 500 μm. In this case, if the thermal spray coating of the undercoat is thinner than 50 μm, the action effect as the undercoat is weak, while if the thickness exceeds 500 μm, the covering effect is saturated and the production cost is increased due to the lamination work. Not.

The black spray coating of yttrium oxide, which is formed directly on the substrate surface or as a top coat through an undercoat or intermediate layer, is formed by oxygen-free plasma spraying, as well as a white spray coating of Y ₂ O ₃ by electron beam or It is good to make the film black by irradiation with a laser beam, or including a blackened layer, about 50 to 2000 μm thick. If the film thickness is less than 50 μm, thermal radiation performance as a black film can be obtained. However, it is because the essential characteristics as a ceramic film, for example, heat resistance, heat insulation, corrosion resistance, wear resistance and the like cannot be sufficiently exhibited. On the other hand, when the thickness is larger than 2000 μm, the mutual bonding force of the ceramic particles constituting the coating is reduced, the coating is easily broken mechanically, and it takes a long time to form the thickness. It is not appropriate because the production cost increases. Therefore, it can be said that the thickness is preferably about 50 to 2000 μm.

The porosity of the yttrium oxide black sprayed coating is about 0.2 to 5% in the case of the oxygen-free plasma sprayed coating. This porosity is remarkably small compared to the porosity of 8 to 15% of the Y ₂ O ₃ white spray coating obtained by conventional atmospheric plasma spraying. The surface of the yttrium oxide sprayed coating blackened treated white spray coating Y ₂ O ₃ by electron beam irradiation or laser beam irradiation, because it is heated to above the melting point of the respective Y ₂ O ₃ (2683K), At the time of irradiation, it is completely melted locally and becomes a non-porous state. However, when solidified by subsequent cooling, cracks are generated due to the contraction phenomenon of the volume, and this becomes a new pore. The presence of this new pore is characterized by much less compared to the porosity of the initial film. However, it is empirically known that the thermal shock resistance of a black sprayed coating of yttrium oxide as a top coat is remarkably reduced in the case of a non-porous coating, so that the non-porous membrane is not preferable in all cases. In the present invention, it is about 5% or less including pores (0.1 to 1%) due to solidification cracks generated after irradiation.

In the present invention, an intermediate layer may be formed between the undercoat (metal layer) under the black sprayed coating of yttrium oxide formed as a top coat. The intermediate layer may be a sprayed coating made of Al ₂ O ₃ alone or a solid solution or mixture of Al ₂ O ₃ and Y ₂ O ₃ . The thickness of this intermediate layer is preferably about 50 to 1000 μm, and if it is thinner than 50 μm, the function as the intermediate layer is not sufficient, while if it is thicker than 1000 μm, the mechanical strength of the film is reduced. This is not appropriate.

The above film thickness is arranged as follows. However, the thickness of the film is not indispensable in obtaining the effects of the present invention, and is a preferable exemplary range.
Undercoat (metal / alloy) 50-500μm
Intermediate layer (Al ₂ O ₃ , Al ₂ O ₃ + Y ₂ O ₃ ) 50 to 1000 μm
Top coat (black Y ₂ O ₃ ) 50-2000 μm

(2) Substrate on which the black sprayed coating of yttrium oxide is formed In the present invention, the target for forming the black sprayed coating of yttrium oxide, that is, the substrate is Al and its alloy, stainless steel, Ti and its alloy, Any material such as quartz, glass, plastic, as well as ceramic sintered bodies (eg, oxides, nitrides, borides, silicides, and mixtures thereof) can be used. Moreover, what gave various vapor deposition films and plating films on these raw materials can be used, and you may form into a film directly or through an undercoat or an intermediate | middle layer on the surface of these raw materials.

(3) Structure of Black Sprayed Coating of Yttrium Oxide The inventors consider that the structure of black sprayed coating of yttrium oxide has the following configuration. That is, in order to improve the adhesion of the yttrium oxide black sprayed coating on the outermost layer covering the substrate (black layer of yttrium oxide black sprayed coating) and the substrate of the yttrium oxide black sprayed coating, After applying a metallic undercoat on the surface of the material, a black sprayed coating of yttrium oxide is formed thereon (two-layer structure coating), and on the undercoat, Al ₂ O ₃ and Al ₂ An intermediate layer made of a solid solution or mixture of O ₃ and Y ₂ O ₃ is formed, and a black sprayed coating of yttrium oxide is formed thereon (three-layer structure coating). Also, if necessary, in the Al ₂ O ₃ and Y ₂ O ₃ intermediate layer in the three-layer structure film, the Al ₂ O ₃ content is increased on the undercoat side and the Y 2O ₃ content on the top coat side. It is also possible to intentionally incline the ceramic content so that the ₂ O ₃ content increases.

(4) Thermal spray method for forming a black sprayed coating of yttrium oxide A black sprayed coating of yttrium oxide can be formed by the thermal spraying method shown below.
(A) For the undercoat (metal / alloy), it is preferable to use an electric arc spraying method, a flame spraying method, a high-speed flame spraying method, an atmospheric plasma spraying method, a low pressure plasma spraying method, or an explosion spraying method.
(B) For the top coat (white Y ₂ O ₃ coating, yttrium oxide black coating), it is preferable to use an air plasma spraying method for the white coating and an oxygen-free plasma spraying method for the black coating.
(C) For the intermediate layer (Al ₂ O ₃ , Al ₂ O ₃ + Y ₂ O ₃ ), it is preferable to use an atmospheric plasma spraying method, an oxygen-free plasma spraying method, or an explosion spraying method.

(5) Method of blackening a white Y ₂ O ₃ sprayed coating A general Y ₂ O ₃ powder material for thermal spraying is a white powder adjusted to a particle size in the range of 5 to 80 μm. When ordinary air plasma spraying is performed using this white powder, the formed sprayed coating also becomes white. On the other hand, in the present invention, to produce a blackened yttrium oxide sprayed coating (Y ₂ O _{3−x type} black sprayed coating) as shown in FIG. The following method is adopted.
(A) Plasma spraying using white Y ₂ O ₃ powder in an atmosphere substantially free of air (oxygen) (hereinafter referred to as “oxygen-free plasma spraying”).
For example, a black sprayed coating can be obtained by plasma spraying using a white Y ₂ O ₃ spray material powder in an inert atmosphere such as Ar or He. In this method, only the surface layer of each yttrium oxide sprayed particle constituting the sprayed coating changes to black, and the center of the particle is often still in a white state. In particular, the larger Y ₂ O ₃ spray material powder having a particle size, observed such a phenomenon, the small particle size particles (less than 5 [mu] m), because the black changes to the center of the particles, Y ₂ O ₃ spray material The black color change of the powder occurs from the surface and seems to propagate to the inside as the processing time (spraying time) elapses.
In an inert gas atmosphere such as Ar or He, a black yttrium oxide sprayed coating can be obtained even at atmospheric pressure or under reduced pressure such as 50 hPa.

(b) The Y ₂ O ₃ white sprayed coating formed by the atmospheric plasma spraying method is irradiated with an electron beam in an inert gas atmosphere under reduced pressure.
For example, when a white sprayed coating of Y ₂ O ₃ obtained by normal atmospheric plasma spraying is irradiated with an electron beam in an Ar gas of 10 ⁻¹ to 10 ⁻³ MPa, only the surface layer portion of the sprayed coating becomes black. Change. In this method, since the surface layer portion of the yttrium oxide particles changed to black is locally melted by the electron beam, there is a tendency to smooth the entire coating. Further, the black change portion of the sprayed coating gradually reaches the inner layer by repeating the number of times of electron beam irradiation. However, if the depth is practically about 30 μm, it is suitable for the purpose of the present invention. I can do things.

The following conditions are recommended as the conditions for electron beam irradiation.
Irradiation atmosphere: 1 × 10 ^{−1 to} 5 × 10 ⁻³ MPa
Irradiation output: 10-30Kev
Irradiation speed: 1-20mm / s
Number of irradiations: 1 to 100 times (continuous or discontinuous)

(C) Laser irradiation of a Y ₂ O ₃ white sprayed coating formed by an atmospheric plasma spraying method. For example, it is possible to change the black color by irradiating a white spray coating of Y ₂ O ₃ obtained by normal atmospheric plasma spraying with a laser beam in the air or in vacuum. In this method, it takes a long time to blacken the entire sprayed coating having a large area, but this method is suitable for blackening only the local part of the sprayed coating.

As the laser beam irradiation conditions, the following are recommended.
Laser output: 2 to 4 kW
Beam area: 5-10mm ²
Beam scanning speed: 5-20mm / s

  The present invention can also obtain a desirable black sprayed coating of yttrium oxide by appropriately combining the above-described methods for forming a black sprayed coating of yttrium oxide (for example, the method (a) and the method (b)). A combination of methods, a combination of the method (a) and the method (c), etc.).

Example 1
In this example, after forming a white thermal spray coating of yttrium oxide according to the prior art and a black thermal spray coating of yttrium oxide specific to the present invention (50 μm thickness) on the surface of a quartz glass protective tube containing a heating wire, The wavelength emitted from the surface of each coating was investigated by passing an electric current through the heating wire. As a result, the white spray coating of yttrium oxide was about 0.2 to 1 μm, but the black spray coating of yttrium oxide was 0.3 to 5 μm, and infrared emission was observed, and a difference in efficiency as a heater was recognized.
In addition, when a black spray coating (50 μm thick) of yttrium oxide is applied to the surface of a halogen lamp (high-intensity lamp) instead of a quartz glass heater, the wavelength of the lamp without the coating is in the range of 0.2 to 3 μm. On the other hand, when the black sprayed coating of yttrium oxide was used, it became over 0.3 to 10 μm, and it was used in the far-infrared region, and the efficiency of the heater was improved. It should be noted that the white sprayed coating of yttrium oxide according to the prior art was in the same wavelength range as when no thermal spray coating was applied or within a wavelength range of less than that.

(Example 2)
In this example, an atmospheric plasma sprayed coating of 80 mass% Ni-20 mass% Cr alloy (100 μm thickness) as an undercoat on one side of a SUS304 stainless steel base material (dimensions 50 mm × length 50 mm × thickness 3.5 mm) Is formed by using a commercially available white Y ₂ O ₃ thermal spraying material powder and oxidizing it by an atmospheric plasma spraying method belonging to the conventional method by a white spray coating of Y ₂ O ₃ and an oxygen-free plasma spraying method suitable for the present invention. Three thermal spray coating specimens each having a black spray coating of yttrium with a thickness of 250 μm were prepared for each condition.
Thereafter, for these test pieces, the appearance test, the porosity of the Y ₂ O ₃ topcoat film in the cross section of the film were measured with an optical microscope and an image analyzer, while the thermal shock test, the topcoat adhesion strength test, and the topcoat The surface micro Vickers hardness was measured, and the properties of the white and black yttrium oxide sprayed coatings were compared.
Table 1 summarizes the above test results. In the lower part of the table, the film production conditions and test methods / conditions are also shown.

As is apparent from the results shown in Table 1, all the thermal spray coatings (Nos. 2 to 5) suitable for the present invention exhibit a black color, and the thermal shock resistance, adhesion strength, etc. of the coatings are Y ₂ O of the comparative example. It has the same performance as ₃ white sprayed coating (No1). The porosity of the coating, although it towards the coating of the present invention are clearly dense turned out, this causes, by irradiation with an electron beam (No2) and laser beam (No3), the coating surface Y ₂ This is probably because the O ₃ particles were melted. However, the surface of the film was not completely non-porous, and it was observed that fine new “cracks” were generated when the Y ₂ O ₃ particles were melted and then cooled and solidified.
The microhardness of the coating surface clearly shows an increase in hardness as compared with the Y ₂ O ₃ white sprayed coating according to the prior art, indicating that the blast erosion resistance is improved.

(Example 3)
In this example, the wear resistance of the black sprayed coating of yttrium oxide as the top coat was investigated using the test piece of Example 2. The test equipment and test conditions tested are as follows.
Test method: A reciprocating wear test method defined in JIS H8503 plating wear test method was adopted.
Test conditions: Load 3.5N, reciprocating speed 40 times / min for 10 minutes (400 times) and 20 minutes (800 times), wear area 30 × 12mm, wear test paper CC320
The evaluation was performed by measuring the weight of the test piece before and after the test, and quantifying the amount of wear from the difference and comparing it.
The test results are shown in Table 2. As is apparent from the results shown in Table 2, the wear amount (No. _{2 to} 5) of the hard yttrium oxide black spray coating on the coating surface is 50 to 60% of the Y ₂ O ₃ white spray coating (No 1) of the comparative example. And excellent wear resistance was observed. This result includes smoothing of the coating surface by black treatment.

The product according to the present invention (base material with black spray coating of yttrium oxide) is excellent in thermal radiation and damage resistance as well as noticeable dirt when applied to conventional Y ₂ O ₃ white spray coating products. It becomes a difficult film. Specifically, in addition to the deposition shield, baffle plate, focus ring, insulator ring, shield ring, bellows cover, electrode, etc., which are plasma-treated using a processing gas containing halogen and its compounds, molten metal resistance is utilized. It can be applied as a surface treatment technique for members such as metal melting crucibles.

It is the figure which compared the external appearance of the white and black yttrium oxide sprayed coating. (1) is a Y ₂ O ₃ white spray coating (a coating formed by plasma spraying using a white Y ₂ O ₃ powder material) according to the prior art (2) is a yttrium oxide coating according to the technology of the present invention. Black spray coating (Y ₂ O ₃ white spray coating is formed by plasma spraying using white Y ₂ O ₃ powder material, then blackened by electron beam irradiation)

Claims (9)

Surface of the substrate, the compounds of the form Y _{2 O 3-x} in which it is covered with a black spray coating composed of yttrium oxide is excellent in heat radiation property and damage resistance, wherein the yttrium oxide sprayed coating covering member. 2. The yttrium oxide sprayed coating member excellent in thermal radiation and damage resistance according to claim 1, wherein an undercoat made of a metal coating is provided under the black sprayed coating of yttrium oxide. The yttrium oxide excellent in thermal radiation and damage resistance according to claim 2, wherein an intermediate layer is provided between an undercoat made of a metal film and a black sprayed film of yttrium oxide formed as a top coat. Thermal spray coating coated member. The undercoat is made of 50 or more of at least one metal selected from Ni and alloys thereof, W and alloys thereof, Mo and alloys thereof, Ti and alloys thereof, Al and alloys thereof, and Mg alloys. The yttrium oxide spray-coated member having excellent thermal radiation and damage resistance according to claim 2 or 3, wherein the yttrium oxide spray-coated member is a metal film formed to a thickness of 500 µm. The yttrium oxide sprayed coating having excellent thermal radiation and damage resistance according to claim 3, wherein the intermediate layer is formed of a coating of a solid solution or a mixture with Al ₂ O ₃ or Y ₂ O _3. Covering member. The black sprayed coating composed of the above yttrium oxide has a blackened yttrium oxide layer in the form of Y ₂ O _3-x in the outer peripheral part or inside of each Y ₂ O ₃ particle constituting the coating. The yttrium oxide having excellent thermal radiation and damage resistance according to any one of claims 1 to 6, wherein the layered body of particles is formed to a thickness of about 50 to 2000 µm. Thermal spray coating coated member. By plasma spraying a white Y ₂ O ₃ powder material directly or on an undercoat applied to the surface of the substrate in an inert gas atmosphere containing no oxygen, Y _A method for producing a yttrium oxide spray-coated member excellent in thermal radiation and damage resistance, characterized by forming a blackened yttrium oxide layer in the form of ₂ O _3-x . First, a white sprayed coating of Y ₂ O ₃ is formed on the surface of the substrate, and then the surface of the white sprayed coating of Y ₂ O ₃ has a compound form of Y ₂ O ₃ by laser beam irradiation. _A method for producing a yttrium oxide spray-coated member excellent in thermal radiation and damage resistance, characterized by forming a blackened yttrium oxide layer that is _-x . A Y ₂ O ₃ white sprayed coating is first formed on the surface of the substrate directly or on an undercoat applied to the surface of the substrate, and then irradiated with an electron beam in an inert gas atmosphere under reduced pressure. by the heat radiation property and damage resistance which form of the compound in the surface layer portion and forming a layer of yttrium oxide blackened a Y _{2 O 3-x} white sprayed coating of the Y ₂ O ₃ For producing a yttrium oxide spray-coated member excellent in resistance.

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