JP5162148B2 - Composite and production method thereof - Google Patents

Description

 The present invention relates to a composite used in a vacuum apparatus and a method for producing the same, and more particularly to corrosion resistance against corrosive gases such as fluorine-based gas, fluorine plasma, and fluorine radicals and reactive gases such as oxygen gas, plasma, and radicals. The present invention relates to an excellent composite and a method for producing the same.

Conventionally, in a vacuum apparatus used in a liquid crystal display manufacturing process or a semiconductor manufacturing process, a strong corrosive gas such as a fluorine-based gas, fluorine plasma, or fluorine radical is used in the apparatus. Therefore, in order to prevent corrosion, since the vapor pressure of fluoride is low, aluminum and aluminum alloys are often used in the apparatus.
Furthermore, in order to improve the corrosion resistance to fluorine-based gases and to improve the resistance to reactive gases such as oxygen gas, plasma and radicals, the surface of aluminum or aluminum alloy used in vacuum devices is subjected to porous anodization treatment. An anodized film is formed by the barrier type anodizing treatment (see, for example, Patent Document 1).
JP 2001-172895 A

However, when a porous anodizing treatment is performed on the surface of aluminum or an aluminum alloy, there is a problem that the amount of gas released increases from 1000 times to 10,000 times compared to before the treatment.
Therefore, a barrier type anodizing process is used to reduce the amount of gas released. However, since the oxide film formed by the barrier type anodizing treatment is thin, it is not possible to secure a thickness sufficient to cover all intermetallic compounds existing on the surface of aluminum or aluminum alloy. There was a problem that the periphery of the was poor in corrosion resistance.
Furthermore, since the mechanical strength of aluminum alloys is lower than that of stainless steel, stainless steel, Inconel (registered trademark), Hastelloy (registered trademark) are used at places where mechanical strength is required at the expense of corrosion resistance. ) Etc. had to be used.

 The present invention has been made in view of the above circumstances, and is excellent in corrosion resistance to corrosive gases such as fluorine-based gas, fluorine plasma and fluorine radicals and reactive gases such as oxygen gas, plasma and radicals, and An object of the present invention is to provide a composite having sufficient mechanical strength and a method for producing the same.

 As a result of intensive studies to solve the above problems, the present inventors formed an aluminum thin film on the surface of a substrate used in a vacuum apparatus and the like, and further formed a barrier type anodic oxide coating on the surface of the aluminum thin film. By forming, the outermost surface is excellent in oxidation resistance in any substrate, or in corrosion resistance to corrosive gases such as fluorine-based gas, fluorine plasma, fluorine radicals, and reactive gases such as oxygen gas, plasma, radicals, etc. Has been found to be able to be formed, and the present invention has been completed. In particular, when the substrate is an aluminum alloy, the formation of an aluminum thin film on the surface of the substrate makes it possible to expose intermetallic compounds present on the surface of the substrate more than when a barrier type anodized film is formed directly on the surface of the substrate. As a result, it was also found that the outermost surface having few pits and excellent corrosion resistance can be formed, and the present invention has been completed.

That is, the composite of the present invention comprises a base, an aluminum thin film formed on the base, and a barrier type anodic oxide coating formed on the aluminum thin film. The base includes stainless steel, magnesium, One or more selected from the group consisting of titanium, nickel-based alloy, copper, and carbon material, the aluminum thin film is formed by sputtering, and the thickness of the aluminum thin film is 0.1 μm or more and 3 μm or less And the thickness of the barrier type anodic oxide coating is 0.1 μm or more and 1 μm or less.

Before SL aluminum thin film preferably contains aluminum 90%.

In the method for producing a composite of the present invention, the surface of a substrate made of one or more selected from the group of stainless steel, magnesium, titanium, nickel-base alloy, copper, and carbon material is sputtered on the surface of the substrate. An aluminum thin film having a thickness of 0.1 μm or more and 3 μm or less is formed, and then a barrier type anodic oxide film having a thickness of 0.1 μm or more and 1 μm or less is formed on the surface of the aluminum thin film. .

 The composite of the present invention comprises a substrate, an aluminum thin film formed on the substrate, and a barrier type anodic oxide film formed on the aluminum thin film, so that the oxidation resistance and corrosion resistance against fluorine and the like are improved. Are better. This is because the aluminum thin film is formed by vacuum deposition or sputtering, so that there are few inclusions and defects, and the barrier type anodic oxide film formed on the aluminum thin film has few defects.

The best mode of the composite of the present invention and the production method thereof will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

 The composite of the present invention is generally composed of a substrate, an aluminum thin film formed on the substrate, and a barrier type anodic oxide film formed on the aluminum thin film.

The substrate is not particularly limited, but a material capable of forming an aluminum thin film on the surface by vacuum deposition or sputtering is used. Among these, stainless steel, aluminum, aluminum alloy, magnesium, titanium It is preferable that it is 1 type, or 2 or more types selected from the group of nickel base alloy, copper, and carbon material.
Among these substrates, examples of aluminum or aluminum alloy include A5052 alloy, A6061 alloy, A2017, A2219, A5056, A6063, AC4A, and AC4C.

Nickel-based alloys are based on nickel and classified by differences in alloy elements such as iron, chromium, niobium, molybdenum, etc. Inconel (registered trademark), nickel as the main component, alloys such as molybdenum, chromium, iron Examples include Hastelloy (registered trademark) classified by elemental differences.
Inconel (registered trademark) includes Inconel 600, Inconel 625, Inconel 718, Inconel 750X, and the like.
Hastelloy (registered trademark) includes Hastelloy B, Hastelloy C, Hastelloy X, Hastelloy G and the like.

 Examples of the carbon material include carbon composites such as glassy carbon, carbon-aluminum, and carbon-epoxy.

 The aluminum thin film preferably contains 90% or more of aluminum. The reason for this is that when the aluminum content is less than 90%, the entire surface of the substrate cannot be completely covered with aluminum. When the barrier type anodizing treatment is applied to the surface of the aluminum thin film, the barrier type anodized film is not spotted. Cannot be formed uniformly. As a result, the outermost surface of the obtained composite may be inferior in oxidation resistance and corrosion resistance.

 The thickness of the aluminum thin film is not particularly limited, but is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 3 μm or less.

 Such an aluminum thin film is preferably formed by vacuum deposition or sputtering. According to vacuum deposition or sputtering, an aluminum thin film having almost uniform thickness with few spots, excellent adhesion to a substrate, and few inclusions and defects can be formed.

The barrier type anodized film is formed by subjecting the surface of the aluminum thin film to a barrier type anodizing treatment.
In order to perform barrier type anodizing treatment on the surface of aluminum thin film and form a barrier type anodized film, organic acid salts such as borate and adipate, and solutions such as phosphate are used as the anodizing solution. In this anodic oxidation solution, the aluminum thin film is electrolyzed with an anode to form a barrier type anodic oxide film having a predetermined thickness on the surface of the aluminum thin film.

The thickness of the barrier type anodic oxide coating is preferably 0.1 μm or more and 1 μm or less, more preferably 0.1 μm or more and 0.8 μm or less.
If the thickness of the barrier type anodized film is less than 0.1 μm, the thickness of the barrier type anodized film is too thin to provide stable corrosion resistance. On the other hand, if the thickness of the barrier type anodic oxide coating exceeds 1 μm, there is a high possibility that dielectric breakdown will occur during the electrolytic treatment, and the dielectric breakdown will cause defects in the barrier type anodic oxide coating and deteriorate the corrosion resistance.

 Since the composite of the present invention comprises a substrate, an aluminum thin film formed on the substrate, and a barrier type anodic oxide film formed on the aluminum thin film, the substrate is not made of aluminum or an aluminum alloy. Even so, it is excellent in oxidation resistance and corrosion resistance against fluorine and the like. This is because the aluminum thin film is formed by vacuum deposition or sputtering, so that there are few inclusions and defects, and the barrier type anodic oxide film formed on the aluminum thin film has few defects.

Next, the manufacturing method of the composite_body | complex of this invention is demonstrated.
In the method for producing the composite of the present invention, an aluminum thin film is formed on the surface of the substrate by vacuum evaporation or sputtering, and then a barrier type anodic oxide film is formed on the surface of the aluminum thin film. And a barrier type anodic oxide film formed on the aluminum thin film.

 In the method for producing a composite of the present invention, examples of the substrate include one or more selected from the group consisting of stainless steel, aluminum, aluminum alloy, magnesium, titanium, nickel-base alloy, copper, and carbon material. .

 An aluminum thin film is formed on the surface of such a substrate by vacuum deposition or sputtering.

 Next, the surface of the aluminum thin film is subjected to a barrier type anodizing treatment to form a barrier type anodized film. As an anodizing solution, organic acid salts such as borate and adipate, phosphates and the like are used. In this anodic oxidation solution, an aluminum thin film is electrolyzed with an anode to form a barrier type anodic oxide coating having a predetermined thickness on the surface of the aluminum thin film, and a base and an aluminum thin film sequentially formed on the base And a composite comprising the barrier type anodic oxide coating.

In the barrier type anodizing treatment described above, the concentration of the anodizing solution is appropriately adjusted, but is preferably 0.1% by weight or more and 30% by weight or less.
The reason why the concentration of the anodizing solution is preferably 0.1% by weight or more and 30% by weight or less is that when the concentration of the anodizing solution is less than 0.1% by weight, a dense barrier type anodized film is difficult to be formed. On the other hand, if the concentration of the anodic oxidation solution exceeds 30% by weight, dielectric breakdown is likely to occur, and a barrier type anodic oxide film having many defects is formed.

In the barrier type anodizing treatment, the voltage to be applied and the time for which the voltage is applied are appropriately adjusted, but a voltage of 50 V or more and 1000 V or less is applied for 15 minutes or more and 360 minutes (6 hours) or less. It is preferable to do.
The reason why the applied voltage is preferably 50 V or more and 1000 V or less is that when the voltage is less than 50 V, only a thin barrier type anodic oxide film can be obtained, whereas when the voltage exceeds 1000 V, This is because defects in the barrier type anodic oxide film due to dielectric breakdown increase.
The reason why the voltage application time is preferably 15 minutes or more and 360 minutes (6 hours) or less is that, since the treatment time is short when the voltage application time is less than 15 minutes, it is a continuous barrier type anodic oxide coating. On the other hand, if the voltage application time exceeds 360 minutes (6 hours), the processing time is too long and it is not practical.

 In the method for producing the composite of the present invention, an aluminum thin film is formed on the surface of the substrate by vacuum deposition or sputtering, and then a barrier type anodic oxide film is formed on the surface of the aluminum thin film. Even when a material other than an alloy is used, the outermost surface with less exposure of intermetallic compounds can be formed, and as a result, a composite having the outermost surface with few defects and excellent oxidation resistance and corrosion resistance against fluorine and the like can be obtained. Can be manufactured.

 EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

"Example 1"
An aluminum alloy (A6061) having a length of 30 mm, a width of 45 mm, and a thickness of 1 mm was used as a substrate, and an aluminum thin film having a thickness of 1 μm was formed on the surface of the substrate by RF magnetron sputtering.
Here, an aluminum target having an aluminum purity of 99.99% was used.
Next, the substrate on which the aluminum thin film is formed is immersed in a 5 wt% ammonium adipate solution, and a voltage of 200 V is applied for 30 minutes in this solution to perform anodization of the aluminum thin film. A barrier type anodic oxide film having a thickness of 250 nm was formed, and a composite body including a base, an aluminum thin film and a barrier type anodic oxide film sequentially formed on the base was obtained.

"Example 2"
Stainless steel (SUS304L) having a length of 30 mm, a width of 45 mm, and a thickness of 1 mm was used as a substrate, and an aluminum thin film having a thickness of 1 μm was formed on the surface of the substrate by RF magnetron sputtering.
Here, an aluminum target having an aluminum purity of 99.99% was used.
Next, the substrate on which the aluminum thin film is formed is immersed in a 5 wt% ammonium adipate solution, and a voltage of 200 V is applied for 30 minutes in this solution to perform anodization of the aluminum thin film. A barrier type anodic oxide film having a thickness of 250 nm was formed, and a composite body including a base, an aluminum thin film and a barrier type anodic oxide film sequentially formed on the base was obtained.

“Comparative Example 1”
An aluminum alloy (A6061) having a length of 30 mm, a width of 45 mm, and a thickness of 1 mm was used as a substrate. The substrate was immersed in a 5 wt% ammonium adipate solution, and a voltage of 200 V was applied in the solution for 30 minutes. The thin film was anodized to form a barrier type anodic oxide film having a thickness of 250 nm on the surface of the substrate, and a composite comprising the substrate and the barrier type anodic oxide film formed on the surface of the substrate was obtained.

"Comparative Example 2"
Stainless steel (SUS304L) having a length of 30 mm, a width of 45 mm, and a thickness of 1 mm was prepared as a substrate. This substrate was not particularly surface treated.

"Evaluation of corrosion resistance"
The composite of Example 1, the composite of Example 2, the composite of Comparative Example 1, and the substrate of Comparative Example 2 were heated in air at 550 ° C. for 48 hours.
Thereafter, the change in the color of the surface before and after heating was examined visually.
The results are shown in Table 1.

From the results of Table 1, the composites of Examples 1 and 2 showed no change in surface color before and after heating.
On the other hand, the composite of Comparative Example 1 was visually observed to have a spot-like brown discoloration on the entire surface, and it was recognized that the gloss was lowered due to the spot-like discoloration. The dot-like brown discoloration is due to the oxidation of the defective portion of the barrier type anodic oxide coating.
Further, in the substrate of Comparative Example 2, brown discoloration was observed on the entire surface, and a spot-like brown discoloration that was darker than the surrounding brown was also observed, and the gloss was lowered by the dot discoloration. It was recognized that This is because the entire surface of the stainless steel is oxidized.
Thus, it was shown that the sample in which the sputtered film of aluminum was formed on the surface of the sample and the barrier type anodic oxidation treatment was performed thereafter was not oxidized and was excellent in corrosion resistance.

In Examples 1 and 2 described above, RF magnetron sputtering was used to form the aluminum thin film. However, the same effects as in Examples 1 and 2 can be obtained even if vacuum deposition is used.
In Examples 1 and 2 described above, an aluminum alloy or stainless steel was used as the substrate. However, even when magnesium, titanium, Inconel (registered trademark), Hastelloy (registered trademark), copper, carbon material, or the like was used, the present invention was implemented. The same effect as in Examples 1 and 2 can be obtained.

The composite of the present invention and the method for producing the same include an oxygen-based gas, an oxygen plasma, an oxygen radical, a fluorine-based gas, a fluorine plasma, a fluorine protective film, an electrode, a ground plate, a heater, etc. It can be applied to other vacuum parts.

Claims (3)

A substrate, an aluminum thin film formed on the substrate, and a barrier type anodic oxide film formed on the aluminum thin film,
The substrate is one or more selected from the group consisting of stainless steel, magnesium, titanium, nickel-base alloy, copper, and carbon material,
The aluminum thin film is formed by sputtering, and the thickness of the aluminum thin film is 0.1 μm or more and 3 μm or less,
The barrier type anodized film has a thickness of 0.1 μm or more and 1 μm or less. The composite according to claim 1, wherein the aluminum thin film contains 90% or more of aluminum. An aluminum thin film having a thickness of 0.1 μm or more and 3 μm or less is formed by sputtering on the surface of one or more substrates selected from the group consisting of stainless steel, magnesium, titanium, nickel-base alloy, copper, and carbon material. And then forming a barrier type anodic oxide film having a thickness of 0.1 μm or more and 1 μm or less on the surface of the aluminum thin film.