JP2003213479A - METHOD OF FORMING Re FILM BY ELECTROPLATING USING Cr(III)- CONTAINING BATH - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of forming a Re film applicable to complicated shapes which can not be solved by a sputtering method, a physical vapor deposition method or the like, and can be used for thin film operation which can not be solved by a thermal spraying method and, e.g. for a corrosion resistant 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 0.001 to 2.0 mol/l perrhenate ions and 0.01 to 10.0 mol/l Cr<SP>3+</SP>ions, and in which the molar ratio of the perrhenate ions to the Cr<SP>3+</SP>ions in the plating bath is ≥0.1, and whose pH is controlled to 0 to 5, and solution temperature to 10 to 80°C is used. The atomic composition of the film can consist of ≥98% Re. <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 film used as a corrosion resistant 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,
And, a method of forming Re by electrolytic plating more easily and cheaply is provided as compared with both methods.

[0005]

Means for Solving the Problems The inventors have found that Re hardly electrolytically precipitates from a bath containing only perrhenate ion as a transition metal ion, but from a bath in which perrhenate ion and Cr ³⁺ ion coexist. By controlling the concentration ratio of perrhenate ions to other metal ions in the bath and the pH of the bath, almost no Cr is electrolytically deposited and only Re with a purity of 98 atomic% or more is electrolytically deposited. I found that

[0006] That is, the present invention, the perrhenate ion to 0.
001 mol / l or more, 2.0 mol / l or less, Cr ³⁺Ions less than 0.01 mol / l
Above 10.0mol / l content, and over-lenium in plating bath
Mumate ion, Cr³⁺When the molar ratio to ions is 0.1 or more
Characterized by using a plating bath consisting of an aqueous solution
Re electroplating method.
It becomes possible to electrolytically deposit Re of the above purity.

[0007] If the perrhenate ion is less than 0.001 mol / l, the Re concentration during plating is low, and if it is more than 2.0 mol / l, an insoluble substance is produced. In addition, the Cr ³⁺ ion concentration is 0.01 mol / l
If less than 1.0, the electrolytic deposition efficiency of Re is significantly low, 10.0 mol / l
If it is more than that, insoluble substances are produced. Therefore, the perrhenate ion is 0.001 mol / l or more and 2.0 mol / l or less, Cr ³⁺
The ion concentration was limited to 0.001 mol / l or more and 10.0 mol / l or less.

[0008] The pH of the plating bath is 0 to 5, 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. If the pH is less than 0, the coating power of the plating will be reduced, and if it is more than 5, the insoluble substances will be large and the fluidity of the liquid will be impaired, and the Re concentration in the coating will be low. Further, when the temperature of the liquid for plating is lower than 10 ° C, the electrolytic deposition efficiency is remarkably lowered, and when it is higher than 80 ° C, the covering power is lowered. Therefore, the bath pH was limited to 0 to 5 and the plating temperature was limited to 10 to 80 ° C. More preferably, the pH of the bath is
2 to 5, the temperature at which plating is performed is 20 to 40 ° C.

[0009] Further, the present invention is the above electrolytic plating method, characterized in that Re is 98% or more in atomic composition, and the rest is Cr and unavoidable impurities. It is possible to add a function according to the type and purpose of the material.

[0010] Further, the present invention is the above-described electrolytic plating method, wherein the plating bath contains an organic acid, which makes it possible to obtain a film having a more stable composition. By identifying the type and concentration of organic acid,
It is possible to obtain a film having a more stable composition. 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.

[0011] 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 acetic acid, propionic acid, formic acid, oxalic acid, acrylic acid, malonic acid, ethylenediaminetetraacetic acid or soluble salts thereof. Amino acids include glycine, alanine, proline, valine, leucine, isoleucine, methionine, serine,
It is preferably at least one selected from cysteine, asparagine, glutamine and tyrosine.

[0012] Further, the present invention 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 occur, and when it is more than 5.0 mol / l, an 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.

[0013] Further, the present invention is the above electroplating 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 0.0001mo
No effect is observed below l / l, and B above 5.0 mol / l
Since a gas containing r as a main component is generated, 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
l or less chloride ion, 0.0001 mol / l or more and 5.0 mol / l or less lithium ion, 0.0001 mol / l or more and 5.0 mol / l or less sodium ion and / or 0.0001 mol / l or more and 5.0 mol / l or less potassium ion The above-mentioned electrolytic plating method is characterized by containing the following. By this, it is possible to reduce the liquid voltage and improve the coating power of the plating, and it is possible to obtain a stable coating composition. The above ion is 0.
Below 0001 mol / l, these effects are insufficient and 5.0
If it is more than mol / l, insoluble matter will be generated and the fluidity of the liquid will be impaired. Therefore, the concentration of these ions is limited to 0.0001 mol / l or more and 5.0 mol / l or less.

[0015]

[Example] Example 1 A copper plate was used after being degreased and washed as a base material. Plating solution is salt
Using chromium oxide, Cr ³⁺Concentration 0.1mol / l, ReO_Four ^-Is 0.01m
ol / l, ReO_Four ^-Ion and Cr³⁺Vinegar as non-ion
Acid: 1.5 mol / l, ammonium chloride: 0.5 mol / l, potassium bromide
Um: A bath added with 0.5 mol / l was used. pH is sulfuric acid and hydroxide
Adjust to 4 with sodium chloride, liquid temperature to 35 ° C, current density
Is 100mA / cm²Electroplating was carried out.

[0016] Example 2 ReO ₄ ^- except that the concentration of 0.1 mol / l was electroless plated under the same conditions as in Example 1. Comparative Example 1 Electroplating was carried out under the same conditions as in Example 1 except that the ReO ₄ ⁻ concentration was 0.0001 mol / l. Comparative Example 2 ReO ₄ ^- except that the concentration 0.005 mol / l and electroplating under the same conditions as in Example 1.

[0017] FIG. 1 shows the plating film compositions of Examples and Comparative Examples,
ReO in plating bath_Four ^-Molarity and Cr³⁺Model with Aeon
The following shows the relationship of the concentration ratio. From this, Cr³⁺Concentration is 0.1 mol / l
In the bath of Comparative Example 1, ReO_Four ^-Is 0.0001 mol / l, plating
The film composition was about 55 atomic% Re-45 primitive% Cr, and Example 1 was used.
ReO_Four ^-Is 0.005mol / l, about 92 atom% Re-8 primitive% Cr
Become. Then, ReO of Example 1 and Example 2_Four ^-concentration
Is 0.01 mol / l or more (ReO _Four ^-Concentration / Cr³⁺98 atoms at concentrations ≥ 0.1)
% Or more of Re.

[0018]

[Effects of the Invention] Re used in corrosion resistant coatings for high temperature equipment members can be formed by aqueous solution electroplating,
It is possible to easily and inexpensively impart heat resistance and corrosion resistance to a device member having a complicated shape.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the plating film compositions of Examples and Comparative Examples and the ReO ₄ ⁻ concentration and ReO ₄ ⁻ / Cr ³⁺ concentration ratio in the plating bath.

   ─────────────────────────────────────────────────── ─── 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 AA30 BA03 BA06 BA08 BA16                       CA01 CA09 CB03 CB13 CB16                       DA02 DA08

Claims (6)

[Claims] 1. A perrhenate ion of 0.001 mol / l or more 2.
Cr containing 0 mol / l or less, Cr ³⁺ ions 0.01 mol / l or more and 10.0 mol / l or less, and perrhenate ions in the plating bath.
^The molar ratio to ³⁺ ions is 0.1 or more, and the pH is 0 to
5. A method for forming a Re film by electrolytic plating, which uses a plating bath composed of an aqueous solution having a liquid temperature of 10 to 80 ° C. 2. The electrolytic plating according to claim 1, wherein the composition of the alloy film formed is such that Re is 98% or more in atomic composition and the balance is Cr and inevitable impurities.
Re film formation method. 3. The plating bath is based on the total metal ion concentration.
The method for forming a Re film by electrolytic plating according to claim 1, which contains an organic acid in a concentration of 0.1 or more and 15.0 equivalents or less. 4. The plating bath is 0.0001 mol / l or more and 5.0 mol / l
The method for forming a Re film by electrolytic plating according to claim 1, which contains 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 bromine ion containing the following bromide ions:
A method for forming a Re film by electrolytic plating as described in. 6. The plating bath is 0.0001 mol / l or more and 5.0 mol / l
Sulfate ion below, 0.0001mol / l or more 5.0mol / l or less chloride ion, 0.0001mol / l or more 5.0mol / l or less lithium ion, 0.0001mol / l or more 5.0mol / l or less sodium ion and / or The method for forming a Re film by electrolytic plating according to claim 1, which contains 0.0001 mol / l or more and 5.0 mol / l or less potassium ions.