JPH0853774A - Corrosion resistant and weather resistant member and its production - Google Patents

Abstract

PURPOSE:To give excellent corrosion resistance and weather resistance by forming a boehmite coat on the surface of an Al base material and further multi-ply coating with a ceramic layer containing metallic ion oxide thereon. CONSTITUTION:After the boehmite coating film expressed by the chemical formula, Al2O3.nH2O, is formed on the surface of the Al or Al alloy base material 1, the oxide ceramic layer 3, in which the metal oxide 4 is dispersed, is laminated thereon. In this case, the oxide ceramic layer 3 preferably contains one of the metal oxide selected from a group consisting of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide and magnesium oxide and the metallic ion oxide preferably contains at least one kind selected from a group of chromium ion, yttrium ion, zirconium ion and magnesium ion. The metallic ion oxide is dispersed in ceramic by dipping the formed ceramic layer into a metallic ion aq. solution, drying and firing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion and weather resistant member and a method for manufacturing the same, and particularly to a member having high corrosion resistance for use in a semiconductor manufacturing apparatus using a corrosive gas, a nuclear power plant, etc. The present invention relates to a member used for an electric wire that is exposed outdoors and requires weather resistance, and a method for manufacturing the member.

[0002]

2. Description of the Related Art Among semiconductor manufacturing equipment, aluminum conductors used in a chemical vapor deposition manufacturing equipment using a corrosive vapor of a low melting point metal or a highly corrosive inorganic halide or organometallic compound as a source gas are With aluminum alone, corrosion proceeds early and cracks grow. For this reason, conventionally, a member used in such an apparatus has been developed by subjecting aluminum to anodizing treatment (alumite processing) or subjecting it to chemical conversion treatment called boehmite treatment.

On the other hand, also for electric wires exposed outdoors for a long time, those whose surface is subjected to anodizing treatment or boehmite treatment are used in order to improve weather resistance.

FIG. 2 is a sectional view showing the structure of an example of a conventional aluminum electric wire. With reference to FIG. 2, this electric wire includes a base material 1 made of aluminum, and a boehmite coating 2 formed on the outer surface of the base material 1 by a chemical conversion treatment.

[0005]

However, the above-mentioned anodized aluminum member or boehmite treated aluminum member is not corrosive to corrosive vapor of low melting point metal or highly corrosive inorganic halide or organometallic compound. , Was not enough.

Further, even when the member subjected to these treatments is used as an electric wire, the weather resistance to long-term outdoor exposure is not sufficient.

An object of the present invention is to solve the above-mentioned problems and to provide a corrosion-resistant weather-resistant member excellent in corrosion resistance and weather resistance, and a method for producing the same.

[0008]

A corrosion resistant and weather resistant member according to the present invention comprises a base material made of aluminum or an aluminum alloy and a chemical formula Al ₂ O formed on the outer surface of the base material.
_{It comprises} a boehmite film represented by ₃ · nH ₂ O and an oxide ceramic layer formed on the outer surface of the boehmite film, characterized in that a metal ion oxide is dispersed in the oxide ceramic layer. There is.

Preferably, the oxide ceramic layer contains any metal oxide selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide and magnesium oxide.

Also preferably, the metal ion oxide is
It is preferable to contain at least one metal ion selected from the group consisting of chromium ion, yttrium ion, zirconium ion and magnesium ion.

The method for producing a corrosion-resistant and weather-resistant member according to the present invention comprises a step of forming a boehmite film on the surface of a base material made of aluminum or an aluminum alloy, a step of forming an oxide ceramic layer on the surface of the boehmite film, and an oxide. And a step of dispersing an oxide of a metal ion in the ceramic layer.

Preferably, the step of forming the oxide ceramics layer on the surface of the boehmite coating includes the step of immersing or applying the substrate on which the boehmite coating is formed in a ceramics precursor composed of a polymerizable organometallic compound. Good.

Also, preferably, the polymerizable organometallic compound is a metal alkoxide or a metal carboxylate.

Further preferably, the polymerizable organometallic compound may contain at least one metal selected from the group consisting of silicon, aluminum, zirconium, titanium and magnesium.

Further, preferably, the step of dispersing the metal ion oxide in the oxide ceramic layer may include the step of immersing the base material on which the oxide ceramic layer is formed in a metal ion aqueous solution and then firing the base material. .

[0016]

FUNCTION Alumina hydrate is contained in the boehmite film obtained by chemical conversion treatment of aluminum or an aluminum alloy. This alumina hydrate includes trihydrate hydrargillite, bayerite, monohydrate boehmite, and diaspore.

Generally, forming the boehmite coating on a substrate made of aluminum or an aluminum alloy is not sufficient to obtain corrosion resistance and weather resistance. However, according to the present invention, this hydrate is directly and effectively utilized to enhance the corrosion resistance and the weather resistance.

That is, in the metal alkoxide and the carboxylic acid ester of metal, Al-OH and Metal-OH react with each other by a dehydration condensation reaction to produce Al-O-Metal.
Generate a bond. According to this invention, the polymerizable organometallic compound immersed in the boehmite film is the above-mentioned Al-O.
-Form an alumina-added metal composite oxide having a metal bond to form a more stable compound. This composite oxide effectively works to improve corrosion resistance and weather resistance. In addition, by impregnating the polymerizable organometallic compound, the originally porous needle-shaped boehmite coating is densified, and corrosion resistance is improved.

Incidentally, only by impregnating the boehmite film with the polymerizable organometallic compound, only a part of the impregnated organometallic compound is changed into the metal oxide. Therefore, the heat treatment further promotes the generation of the metal oxide, and the metal oxide can be almost completely converted into the metal oxide by heating at about 600 ° C.

According to the present invention, chromium ions,
After impregnating at least one of yttrium ion, zirconium ion and magnesium ion, firing is performed to disperse the oxide of the impregnating ion in the boehmite film. This impregnated ion oxide acts as a barrier against corrosive substances, and can further improve corrosion resistance and weather resistance.

[0021]

【Example】

(Example 1) According to the present invention, an example of an electric wire made of a corrosion and weather resistant member was produced as follows.

First, a pure aluminum wire 1 having a diameter of 2 mm.
5% Na ₂ CO ₃ + 2.m held at a temperature of 90 ° C.
Immersion in 5% Na ₂ CrO ₄ for 30 minutes. A boehmite coating composed of alumina hydrate was formed on the surface of the wire after the immersion to a thickness of about 1 μm. Next, the wire rod on which this film is formed is treated with tetraethoxysilane 20w.
After dipping for about 10 minutes in an isopropanol solution containing t% + tetrabutoxytitanium 2 wt%, it was dried with hot air at 80 ° C. The immersion and the drying at 80 ° C. were performed 5 times. Subsequently, the wire rod after the immersion and drying was immersed in an aqueous solution of 50 g / l of yttrium nitrate hexahydrate + 1 g / l of zirconium oxynitrate, and then heated in an oxygen stream at 500 ° C. for 10 minutes.

FIG. 1 is a sectional view showing the structure of the electric wire thus obtained. Referring to FIG. 1, this electric wire
The substrate 1 was made of pure aluminum, the boehmite film 2 was formed on the outer surface of the substrate 1, and the oxide ceramic layer 3 containing titanium oxide was formed on the outer surface of the boehmite film 2. Further, in the oxide ceramic layer 3, the metal ion oxide 4 including the oxides of yttrium ion and zirconium ion was dispersed.

The surface of the thus constructed electric wire was analyzed by an energy dispersive X-ray fluorescence spectrometer. As a result, the composition ratio of the metal elements on the surface was Al = 82 atom.
%, Si = 10 atom%, Y = 6 atom%, Zr =
1 atom% and Ti = 1 atom%.

The coating portion 5 composed of the boehmite coating 2 and the oxide ceramic layer 3 in which the metal ion oxide 4 is dispersed has an insulating property and an alternating current of 60
When the dielectric breakdown voltage was measured at Hz, a value of 500 V was shown. Therefore, it was found that this electric wire having such a covering portion 5 can also be used as an insulated electric wire.

Further, this electric wire was left in a container controlled by a gallium partial pressure of 10 mmTorr for 30 hours,
The depth of corrosion holes present on the surface of the wire was determined by observing the cross section. As a result, the average value was 2 μm.

Further, the color tone of the produced electric wire was measured in the Munsell mode using a Minometer lightness meter CR-200. As a result, the Munsell value was 4.0. In order to examine the weather resistance of this electric wire, a one-year outdoor exposure test was conducted. As a result, even after 1 year of outdoor exposure, the Munsell value was only increased to 4.5.

For comparison, a similar outdoor exposure test was conducted on untreated high-purity aluminum electric wires, and the Munsell value rose from 2.8 to 5.9. Further, when a similar outdoor exposure test was performed on an electric wire that was only formed with a boehmite film by chemical conversion treatment, the Munsell value increased from 3.8 to 5.5.

Further, in order to investigate the corrosion resistance of this electric wire,
A test was conducted under the following conditions according to JIS Z2371.

Temperature: 35 ° C. ± 2 ° C. Salt water concentration: 5% ± 1% Salt spray amount: 1.8-3.0 cc / hr pH: 6.5-7.2 Salt spray time: 500 hr Such salt spray When the electric wire was examined after the test, there was almost no change on the surface.

(Comparative Example) For comparison, an electric wire in which a metal ion oxide was not dispersed in the oxide ceramic layer was prepared as follows.

First, a pure aluminum wire 1 having a diameter of 2 mm
5% Na ₂ CO ₃ + 2.m held at a temperature of 90 ° C.
Immersion in 5% Na ₂ CrO ₄ for 30 minutes. A boehmite coating composed of alumina hydrate was formed on the surface of the wire after the immersion to a thickness of about 1 μm. Next, the wire rod on which this film is formed is treated with tetraethoxysilane 20w.
After dipping for about 10 minutes in an isopropanol solution containing t% + tetrabutoxytitanium 2 wt%, it was dried with hot air at 80 ° C. This dipping and drying process was repeated 5 times as in Example 1. As a result, Al = 84 atom%, Si
= 13 atom%, Ti = 3 atom% of the coating portion was formed 5 μm.

The electric wire was left in a container controlled by a gallium partial pressure of 10 mmTorr for 30 hours, and the depth of corrosion holes existing on the surface of the wire was determined by observing the cross section. As a result, the average value was 4 μm.

As for the weather resistance of this electric wire, the color tone of the electric wire was set to CR-2 made by Minolta as in Example 1.
It was investigated by measuring in the Munsell mode using 00. As a result, the Munsell value of 3.7 was 1
The Munsell value had risen to 4.9 after the annual outdoor exposure test.

Further, the corrosion resistance of the sample was also examined by conducting a salt spray test under the same conditions as in Example 1. As a result, a white corrosion product was formed on the surface of the electric wire after the salt spray test. In addition, it was confirmed that the electric wire of Example 1 in which the metal oxide layer was impregnated with inorganic ions had a superior difference even in the test for 500 hours.

Example 2 Another example of an electric wire made of a corrosion resistant and weather resistant member was produced according to the present invention as follows.

First, 1 m of a 6110 aluminum alloy (Japanese Industrial Standard) rod having a wire diameter of 5 mm was immersed in 0.5 M triethanolamine maintained at a temperature of 95 ° C. for 30 minutes. A boehmite coating composed of alumina hydrate having a size of 1 μm or less was formed on the surface of the wire after the immersion. Next, the wire on which this film was formed was mixed with 8 mol% of tetrabutyl orthosilicate, 32 mol% of water, and 60 mol% of ethanol, and 1.2 N concentrated nitric acid was added to 1/100 mol of tetrabutyl orthosilicate. Add 70 ℃
After immersing in the liquid obtained by heating and stirring for 2 hours,
The step of heating at 400 ° C. for 10 minutes was repeated 10 times. Subsequently, the wire rod after the dipping and heating is treated with chromic anhydride 1
After dipping in an aqueous solution of 0 g / l + zirconium oxynitrate 5 g / l, heating was carried out in an oxygen stream at 500 ° C. for 10 minutes.

The electric wire thus obtained had the same structure as the electric wire of Example 1 shown in FIG. However, the substrate 1 was made of an aluminum alloy, the oxide ceramic layer 3 contained silicon oxide, and the metal ion oxide 4 contained chromium ions and zirconium ions. The other configurations are similar to those of the first embodiment, and thus the description thereof is omitted.

The surface of the electric wire thus constructed was analyzed by an energy dispersive fluorescent X-ray spectroscopic analyzer. As a result, the composition ratio of the metal element on the surface was Al = 78 atom.
%, Si = 11 atom%, Cr = 7 atom%, Zr
= 4 atom%.

Further, the color tone of the produced electric wire was measured in the Munsell mode by using Minolta brightness meter CR-200. As a result, the Munsell value was 5.6. In order to examine the weather resistance of this electric wire, an outdoor exposure test for one year was conducted as in Example 1. As a result, the Munsell value is 5.
It only rose to 8.

Further, in order to investigate the corrosion resistance of the sample, a salt spray test was conducted under the same conditions as in Example 1 in accordance with JIS Z2371. As a result, there was almost no change on the surface of the electric wire even with salt spray.

It should be noted that the disclosure of the above embodiments is merely specific examples of the present invention and does not limit the technical scope of the present invention.

That is, in the present invention, a compound such as a metal alkoxide or a metal carboxylate can be used as the polymerizable organometallic compound. Also,
As the metal alkoxide, ethoxide, propoxide, butoxide and the like are used. Further, the metal carboxylate is preferably a metal salt with an organic acid such as naphthenic acid, caprylic acid, stearic acid, or octylic acid.

As the oxide ceramics formed by the impregnation treatment with the polymerizable organometallic compound, almost all metal oxide ceramic coatings can be formed. For example, silicon oxide, aluminum oxide, Examples thereof include zirconium oxide, titanium oxide and magnesium oxide.

[0045]

As described above, according to the present invention, a member excellent in corrosion resistance and weather resistance can be obtained.

Therefore, the corrosion-resistant weather-resistant member according to the present invention is used as a highly corrosion-resistant member used in a semiconductor manufacturing apparatus or a nuclear power plant that uses corrosive gas, or for an electric wire that is exposed to the outdoors for a long time and requires weather resistance. It can be effectively applied as a member to be used.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of an example of an electric wire made of a corrosion resistant and weather resistant member according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a conventional aluminum electric wire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material 2 Boehmite film 3 Oxide ceramics layer 4 Metal ion oxide 5 Covering part In addition, in each figure, the same code | symbol shows the same or corresponding part.

Claims (8)

[Claims] 1. A base material made of aluminum or an aluminum alloy, and a chemical formula Al ₂ O ₃ .n formed on the outer surface of the base material.
A boehmite film represented by H ₂ O, and an oxide ceramic layer formed on the outer surface of the boehmite film, wherein a metal ion oxide is dispersed in the oxide ceramic layer. Corrosion resistant and weather resistant material. 2. The corrosion resistant and weather resistant member according to claim 1, wherein the oxide ceramics layer contains any metal oxide selected from the group consisting of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide and magnesium oxide. . 3. The metal ion oxide is at least one selected from the group consisting of chromium ion, yttrium ion, zirconium ion and magnesium ion.
The corrosion-resistant weather-resistant member according to claim 1 or 2, comprising three metal ions. 4. A step of forming a boehmite coating on the surface of a base material made of aluminum or an aluminum alloy, a step of forming an oxide ceramics layer on the surface of the boehmite coating, and a step of forming metal ions in the oxide ceramics layer. And a step of dispersing an oxide. 5. The step of forming an oxide ceramics layer on the surface of the boehmite coating includes a step of immersing or applying the substrate on which the boehmite coating is formed in a ceramics precursor composed of a polymerizable organometallic compound. The method for manufacturing a corrosion-resistant and weather-resistant member according to claim 4. 6. The method for producing a corrosion-resistant weather-resistant member according to claim 5, wherein the polymerizable organometallic compound is a metal alkoxide or a metal carboxylate. 7. The polymerizable organometallic compound contains at least one metal selected from the group consisting of silicon, aluminum, zirconium, titanium and magnesium.
The method for manufacturing a corrosion-resistant and weather-resistant member according to claim 5. 8. The step of dispersing the metal ion oxide in the oxide ceramic layer includes a step of immersing the base material on which the oxide ceramic layer is formed in a metal ion aqueous solution and then firing the substrate. The manufacturing method of the corrosion-resistant weather-resistant member in any one of Claims 4-7.