JP2003213483A - METHOD OF FORMING Re-Cr ALLOY FILM BY ELECTROPLATING USING ALKALI OR ALKALINE-EARTH METALLIC ION-CONTAINING BATH - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming an Re-Cr alloy film applicable to complicated shapes which can not be solved by a sputtering method, a physical vapor deposition method or the like, and used for thin film operation which can not be solved by a thermal spraying method, and, e.g. for a corrosion resistant alloy film for a high temperature apparatus member such as a turbine blade which is applied inexpensively and simply compared with both the cases by aqueous solution electroplating. <P>SOLUTION: A plating bath consisting of an aqueous solution containing ≥0.0001 to <2.0 mol/l perrhenate ions, >0.001 to 10.0 mol/l chromium (III) ions, and 0.001 to 10.0 mol/l of ions of at least one or more kinds of elements selected from potassium, rubidium, cesium, calcium, strontium and barium, and whose pH is controlled to 0 to 8, and solution temperature to 10-80°C is used. The atomic composition of the alloy film can consist of 0%<Re<98%, and the balance Cr with inevitable impurities. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a Re-Cr alloy film used as a corrosion resistant alloy film for high temperature equipment members.

[0002]

2. Description of the Related Art Ni-based superalloy substrates used for jet engines, gas turbine blades, etc. are strongly required to have oxidation resistance and corrosion resistance. Therefore, the surface is subjected to a diffusion treatment of Al or the like, and an Al ₂ O ₃ film is applied, for example, to obtain high temperature oxidation resistance. However, its performance is not sufficient, and Pt
Means such as providing a diffusion barrier using the above have been developed. When Re is used as the diffusion barrier layer, the high temperature corrosion resistance can be improved. Further, Re has excellent thermal shock resistance and is used as a high temperature member such as various combustors such as a rocket engine combustor and a high temperature nozzle. Heretofore, the following methods have been known as methods for forming a Re film or a Re alloy film.

(1) Sputtering method or physical vapor deposition method While it is easy to control the film thickness and composition, there are many restrictions on the size and shape of the base material, the equipment is large-scale, the operation is complicated, and defects and cracks are generated. It has a problem that many films are formed. (2) Thermal spraying method Thin film (10 μm or less) where a film with many defects is formed.
It is not suitable for the formation of, the yield is poor and it is uneconomical. (3) Electroplating method for Re alloys Re content up to 50 wt% (lower atomic composition ratio) Ni-Cr-Re and Re content up to 85 wt% (63 atoms)
%) Re-Ni alloy plating for electrical contacts is known, but the Re content is low.

[0004]

DISCLOSURE OF THE INVENTION The present invention makes it possible to apply a complex shape which cannot be solved by a sputtering method or a physical vapor deposition method, and at the same time, a thin film construction which cannot be solved by a thermal spraying method,
In addition, a method for forming a Re-Cr alloy film by electrolytic plating more easily and cheaply than both methods is provided.

[0005]

The present inventors have found that the activity of perrhenate ion can be controlled by including an appropriate type and concentration of alkali or alkaline earth metal ion in the bath. . As a result, we have developed a method for electrolytic plating of Re-Cr alloy coatings whose coating composition can be freely controlled.

[0006] That is, the present invention, the perrhenate ion to 0.
0001 mol / l or more and less than 2.0 mol / l, 0.003% chromium (III) ion
1 or more and 10.0 mol / l or less, and 0.001 or more 1 or more ions selected from potassium, rubidium, cesium, calcium, strontium, and barium.
Re-C characterized by using a plating bath made of an aqueous solution containing 0.0 mol / l or less, a pH of 0 to 8, and a liquid temperature of 10 to 80 ° C.
This is an electroplating method for r alloys, which makes it possible to freely control the film composition within the atomic composition range of 0 <Re <98%.

When the perrhenate ion is less than 0.0001 mol / l,
Re is not contained in the plating, and if it is more than 2.0 mol / l, Cr is not contained in the plating. In addition, chromium (III) ions
At 0.001 mol / l or less, Cr is not included in the plating and 10.0 mo
If the amount is more than 1 / l, insoluble matter is produced and the fluidity of the liquid is impaired.

[0008] Further, potassium, rubidium, cesium, mosquito
A few selected from Lucium, Strontium and Barium
If the ion concentration of at least one kind is less than 0.001 mol / l, ReO
_Four ^-The effect of suppressing the activity is small, even if it exceeds 10.0 mol / l
The effect does not increase any further. Therefore, over Renyu
Chromate (III) ion
ON greater than 0.001 and 10.0 mol / l or less, and potassium,
Rubidium, cesium, calcium, strontium,
Ion concentration of at least one selected from barium
Was limited to 0.001 or more and 10.0 mol / l or less.

[0009] The pH of the plating bath is 0 to 8, and the liquid temperature at which plating is performed is
10-80 degreeC is preferable. With these, the covering power is high,
Plating having a uniform composition can be obtained. When the pH is less than 0, the coating power of the plating is reduced, and when it is more than 8, the amount of insoluble substances is large and the fluidity of the solution is impaired. In addition, the temperature of the plating solution
If it is lower than 10 ° C, the electrolytic deposition efficiency is remarkably reduced, and if it is higher than 80 ° C, the covering power is lowered. Therefore, the pH of the bath is 0-8,
The liquid temperature at which plating is performed was limited to 10 to 80 ° C. More preferably, the pH of the bath is 2-5, the temperature at which the plating is performed is 20-40
℃.

Further, the present invention is characterized in that the composition of the alloy film to be formed is 0% <Re <98% in atomic composition, and the balance is Cr except for unavoidable impurities. This is a method, which makes it possible to give the material to be plated with a function according to the type and purpose of the base material.

[0011] Further, the present invention is the above-described electrolytic plating method, wherein the plating bath contains an organic acid, which facilitates control of the coating composition. By specifying the type and concentration of the organic acid, the film composition can be controlled more accurately. If the organic acid concentration is less than 0.1 equivalent relative to the total metal ion concentration, a sufficient effect cannot be obtained, and if it is more than 15.0 equivalent, an insoluble matter is produced and the fluidity of the liquid is impaired. Therefore, the organic acid concentration is limited to 0.1 or more and 15.0 equivalents or less.

[0012] The organic acid is preferably at least one selected from hydroxycarboxylic acids, carboxylic acids and amino acids. Hydroxycarboxylic acids include lactic acid, hydroxybutyric acid, glycolic acid, mandelic acid, malic acid, tartaric acid,
It is preferably at least one selected from gluconic acid, citric acid and soluble salts thereof. The carboxylic acid is preferably at least one selected from formic acid, propionic acid, acetic acid, oxalic acid, acrylic acid, malonic acid, ethylenediaminetetraacetic acid or their soluble salts. Amino acids include glycine, alanine, proline, valine, leucine, isoleucine, methionine, serine,
It is preferably at least one selected from cysteine, asparagine, glutamine and tyrosine.

[0013] The present invention also provides 0.0001 mol / l or more and 5.0 mol / l or less ammonium ions and / or 0.0001 mol / l or more.
The above electrolytic plating method is characterized by containing 5.0 mol / l or less of boric acid, which stabilizes the bath and enables formation of a film having a uniform thickness. When ammonium ion or boric acid is less than 0.0001 mol / l, plating spots are generated, and when it is more than 5.0 mol / l, insoluble matter is generated and the fluidity of the liquid is impaired. Therefore, ammonium ions and boric acid are limited to 0.0001 mol / l or more and 5.0 mol / l or less.

[0014] The present invention is also the above electrolytic plating method, wherein the plating bath contains 0.0001 mol / l or more and 5.0 mol / l or less bromine ions, whereby a toxic chlorine gas Suppress the occurrence. Bromine ion concentration is 0.0001
If it is less than mol / l, no effect is seen, and if it is more than 5.0 mol / l, a gas containing Br as a main component is generated, so the bromine ion concentration is limited to 0.0001 mol / l or more and 5.0 mol / l or less. .

Further, the present invention, the plating bath, 0.0001mol / l or more 5.0mol / l or less sulfate ions, 0.0001mol / l or more 5.0mol / l
The above electrolytic plating method is characterized by containing less than or equal to 1 chloride ion, which makes it possible to reduce the voltage between liquids and improve the coating power of plating, and to obtain a stable coating composition. You can The above ion is 0.
If it is less than 0001mol / l, these effects are insufficient and 5.0mo
If it is more than 1 / l, insoluble matter will be generated and the fluidity of the liquid will be impaired.
Therefore, the concentration of these ions should be 0.0001 mol / l or more 5.0
Limited to mol / l or less.

[0016]

Example 1 A copper plate was used as a substrate after degreasing and cleaning. The plating solution is K ⁺
The ion concentration was 1.0 mol / l, and as a bath component other than K ⁺ , Re
^{_{O 4 -: 0.1mol / l,}} Cr 3+: 0.5mol / l, acetic acid: 1.5 mol / l, ammonium chloride: 0.5 mol / l, ammonium bromide: 0.5 mol
A plating bath consisting of an aqueous solution added with / l was used. The pH was adjusted to 4 with sulfuric acid and sodium hydroxide, and the liquid temperature was 35 ° C.
Electrolytic plating was performed at a current density of 100 mA / cm ² .

Example 2 Electroplating was performed under the same conditions as in Example 1 except that the K ⁺ ion concentration was 2.0 mol / l. Comparative Example 1 Electroplating was performed under the same conditions as in Example 1 except that the K ⁺ ion concentration was 0 mol / l.

[0018] FIG. 1 shows the plating film compositions of Examples and Comparative Examples,
The relationship of K ⁺ concentration in the plating bath is shown. From this, as the K ⁺ increases, as shown in Fig. 1, the
It can be seen that the Re concentration decreases.

[0019]

EFFECT OF THE INVENTION Since the Re-Cr alloy used for the corrosion resistant alloy film for high temperature equipment members can be formed by aqueous solution electroplating, heat resistance and corrosion resistance can be easily and inexpensively applied to equipment members having complicated shapes. Can be given.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the plating film compositions of Examples and Comparative Examples, the molar concentrations of ReO ₄ ⁻ and Cr ^{3+ in} the plating bath, and the molar concentration ratio.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshio Narita             Shinkotoni 1-9-7-8, Kita-ku, Sapporo-shi, Hokkaido (72) Inventor Shigenari Hayashi             18-1-36 Odori Nishi, Chuo-ku, Sapporo-shi, Hokkaido             Nfinito Odori 801 (72) Inventor Takayuki Yoshioka             2-1-23 Kita 22 Nishi, Kita-ku, Sapporo-shi, Hokkaido             Lawr N22 505 (72) Inventor Hiroshi Yawa             Fujisawa City, Kanagawa Prefecture Fujisawa 4-2-1 Stock Association             Inside the Ebara Research Institute (72) Inventor Michiaki Soma             6-5-2-21 cold from Nishi-ku, Sapporo-shi, Hokkaido             Article 6 201 F-term (reference) 4K023 AB24 AB49 BA03 BA08 BA16                       BA29 CA01 CA09 CB03 CB13                       CB16 DA02 DA03 DA08

Claims (6)

[Claims] 1. A perrhenate ion of 0.0001 mol / l or more
Less than 2.0 mol / l, more than 0.001 of chromium (III) ions 10.0
mol / l or less and potassium, rubidium, cesium,
Calcium, strontium, barium containing at least one or more ions of 0.001 or more and 10.0 mol / l or less, characterized by using a plating bath made of an aqueous solution having a pH of 0 to 8 and a liquid temperature of 10 to 80 ° C. Re by electrolytic plating
-Method of forming Cr alloy coating. 2. The composition of the alloy film formed is 0% <Re <98% in atomic composition, and the balance is Cr except for unavoidable impurities.
The method for forming a Re-Cr alloy film by electrolytic plating according to claim 1, wherein 3. The plating bath is based on the total metal ion concentration.
A method for forming a Re-Cr alloy film by electrolytic plating, which comprises a concentration of 0.1 to 15.0 equivalents inclusive of an organic acid. 4. The plating bath is 0.0001 mol / l or more and 5.0 mol / l
A method for forming a Re-Cr alloy film by electrolytic plating, which comprises the following ammonium ions and / or 0.0001 mol / l or more and 5.0 mol / l or less boric acid. 5. The plating bath is 0.0001 mol / l or more and 5.0 mol / l
A method for forming a Re-Cr alloy film by electrolytic plating, which comprises the following bromine ions. 6. The plating bath is 0.0001 mol / l or more and 5.0 mol / l
A method for forming a Re-Cr alloy film by electrolytic plating, comprising the following sulfate ion and 0.0001 mol / l or more and 5.0 mol / l or less chloride ion.