JP3904197B2 - Method for forming Re film by electrolytic plating - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming a Re film used for a corrosion-resistant alloy film for a high-temperature device member.
[0002]
[Prior art]
Ni-base superalloy base materials used for jet engines and gas turbine blades are strongly required to have oxidation resistance and corrosion resistance. For this reason, diffusion treatment of Al or the like is performed on the surface, for example, an Al ₂ O ₃ film is applied to obtain high-temperature oxidation resistance. However, its performance is not sufficient, and means such as providing a diffusion barrier using Pt or the like on the substrate have been developed. When Re is used as the diffusion barrier layer, the high temperature corrosion resistance can be improved. Re is excellent in 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. Until now, the following methods are known as methods for forming the Re film and the Re alloy film.
[0003]
(1) Sputtering method or physical vapor deposition method While film thickness and composition are easy to control, (1) there are many restrictions on the size and shape of the substrate, (2) the apparatus is large and the operation is complicated, 3) There are problems such as the formation of a film with many defects and cracks.
(2) Thermal spraying method (1) A film with many defects is formed, (2) It is not suitable for forming a thin film (less than 10 μm), (3) The yield is poor and uneconomical. .
(3) Electroplating method for Re alloy
Ni-Cr-Re with a maximum Re content of 50% by weight (lower percentage in atomic composition) and Re-Ni alloys for electrical contacts with a maximum Re content of 85% by weight (63 atomic%) Although plating is known, the Re content is low.
[0004]
[Problems to be solved by the invention]
The present invention makes it possible to apply complex shapes that cannot be solved by sputtering or physical vapor deposition, as well as thin film application that cannot be solved by thermal spraying, and electrolytic plating of Re at a lower cost and easier than both. A method of forming is provided.
[0005]
[Means for Solving the Problems]
As a result of examining the electrolytic plating method of Re, the present inventors have included an organic acid having at least one functional group selected from a hydroxyl group, a carbonyl group, and an amino group in a plating bath, and further, in the plating bath It was found that by controlling the composition of the metal ions and the organic acid, a Re film having an atomic composition of Re of 98% or more can be formed.
[0006]
That is, the present invention is a perrhenate ion 0.1-8.0 mol / l, the total amount of at least one of nickel, iron, cobalt, chromium (III) ions 0.005-2.0 mol / l, lithium ions and sodium ions The total amount of at least one selected from the group consisting of 0.0001 mol / l to 5.0 mol / l, and the concentration of at least one organic acid selected from carboxylic acid, hydroxycarboxylic acid, and amino acid is based on the total metal ion concentration Re electroplating method characterized by using a plating bath consisting of an aqueous solution of more than 5.0 equivalents and less than or equal to 15.0 equivalents, pH of 0 to 8, and liquid temperature of 10 to 80 ° C. It is possible to form a Re film that becomes a heat and corrosion resistant alloy film.
[0007]
If the perrhenate ion is less than 0.1 mol / l, 98% or more of Re is not contained in the plating, and if it is more than 8.0 mol / l, an insoluble material is generated in the bath. In addition, if the total amount of at least one ion of nickel, iron, cobalt, and chromium (III) is less than 0.005, the plating efficiency is remarkably lowered, and if it exceeds 2.0 mol / l, the Re concentration during plating is 98% in atomic composition. Less than. If the total amount of at least one of lithium ions and sodium ions is not 0.0001 mol / l or more, the Re concentration in the plating is less than 98% in atomic composition, and if it exceeds 5.0 mol / l, an insoluble substance is generated in the bath, The fluidity of the liquid is impaired.
[0008]
Even if the above conditions are satisfied, if the concentration of at least one organic acid selected from carboxylic acid, hydroxycarboxylic acid, and amino acid is 5.0 equivalents or less with respect to the total metal ion concentration, the Re concentration during plating is the atomic composition. If it is less than 98% and 15.0 equivalents or more, an insoluble material is generated in the bath, and the fluidity of the liquid is impaired. Therefore, the perrhenate ion is 0.1 to 8.0 mol / l, the total amount of at least one of nickel, iron, cobalt, and chromium (III) ions is 0.005 to 2.0 mol / l, and at least selected from lithium ions and sodium ions. The total amount of one kind is 0.0001 mol / l or more and 5.0 mol / l or less, and the concentration of at least one organic acid selected from carboxylic acid, hydroxycarboxylic acid, and amino acid is more than 5.0 equivalent and less than 15.0 equivalent with respect to the total metal ion concentration Limited to.
[0009]
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 soluble salts thereof. The hydroxycarboxylic acid is preferably at least one selected from lactic acid, hydroxybutyric acid, glycolic acid, mandelic acid, malic acid, tartaric acid, gluconic acid, citric acid, or soluble salts thereof. The amino acid is preferably at least one selected from glycine, alanine, proline, valine, leucine, isoleucine, methionine, serine, cysteine, asparagine, glutamine, and tyrosine.
[0010]
The pH of the plating bath is preferably 0 to 8, and the temperature at which plating is performed is preferably 10 to 80 ° C. With these, plating with high covering power and uniform composition can be obtained. If the pH is less than 0, the covering power of the plating is reduced, and if it is more than 8, there are many insoluble substances and the fluidity of the liquid is impaired. In addition, when the temperature at which plating is performed is lower than 10 ° C, the electrolytic deposition efficiency is remarkably reduced, and when it is higher than 80 ° C, the covering power is reduced. Therefore, the pH of the bath was limited to 0-8, and the temperature at which plating was performed was limited to 10-80 ° C. More preferably, the pH of the bath is 2 to 5, and the temperature at which plating is performed is 40 to 60 ° C.
[0011]
In the present invention, when the bath contains at least one ion selected from potassium, rubidium, cesium, calcium, strontium, and barium, the total amount of at least one selected from lithium ions and sodium ions in the bath Is more than the total amount of at least one ion selected from potassium, rubidium, cesium, calcium, strontium, and barium. This enables higher concentration Re plating.
[0012]
Since the total amount of at least one selected from lithium ions and sodium ions is less than the total amount of at least one ion selected from potassium, rubidium, cesium, calcium, strontium, and barium, sufficient effects cannot be obtained. The total amount of at least one selected from sodium ions was limited more than the total amount of at least one selected from potassium, rubidium, cesium, calcium, strontium, and barium.
[0013]
In the present invention, the composition of the alloy film to be formed has an atomic composition of Re of 98% or more, and the rest are Ni, Co, Fe, Mn, Cr, Mo, W, Nb, Ta, Hf, Si, Al Ti, Mg, Pt, Ir, Rh, Au, Ag, P, B, C, Y, is the above-described electrolytic plating method characterized by being an unavoidable impurity and selected from Ce, This makes it possible to provide functions according to the base material and purpose.
[0014]
Further, the present invention is characterized in that the plating bath contains 0.0001 mol / l or more and 5.0 mol / l or less sulfate ion and 0.0001 mol / l or more and 5.0 mol / l or less chloride ion. This is a plating method, and this makes it possible to reduce the liquid voltage and improve the covering power of plating, and to obtain a stable coating composition. If the above ion is less than 0.0001 mol / l, these effects are insufficient, and if it is more than 5.0 mol / l, an insoluble material is formed and the fluidity of the liquid is impaired. Therefore, these ion concentrations were limited to 0.0001 mol / l or more and 5.0 mol / l or less.
[0015]
【Example】
A copper plate was used after degreasing and washing as a base material for Examples and Comparative Examples. The plating solution used contained perrhenate ion, nickel sulfate, chromium chloride, and citric acid. A plating bath was prepared in which the chemical equivalent ratio of metal ions and organic acid in the plating bath was changed in the range of 2-11. The pH of the bath was adjusted in the range of 3 to 8, and the pH was adjusted using lithium hydroxide and sulfuric acid. Electrolytic plating was performed at a plating solution temperature of 50 ° C. and a current density of 100 mA / cm ² .
[0016]
The plating film composition determined by fluorescent X-ray analysis is shown below. In FIG. 1, the horizontal axis represents the chemical equivalent of the organic acid to the metal ions in the plating solution, and the vertical axis represents the atomic composition of the film. As can be seen from FIG. 1, the plating film composition depends on the ratio of metal ions and organic acid in the plating solution, and the higher the ratio of organic acid, the higher the Re concentration in the plating film. In an example in which the chemical equivalent ratio of the organic acid to the total metal ions is 5 or more, the Re concentration of the plating film is 98% or more in terms of atomic composition. As described above, by controlling the composition of the metal ions and the organic acid in the plating solution, it is possible to form a Re plating film having an atomic composition of 98% or more with good reproducibility.
[0017]
【The invention's effect】
Since Re used for a corrosion-resistant film for high-temperature device members can be formed by aqueous solution electroplating, heat and corrosion resistance can be easily and inexpensively provided to device members having complicated shapes.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the chemical equivalent ratio of metal ions and organic acids in plating baths of examples and comparative examples, and the plating layer composition.

Claims (4)

Perrhenate ion is 0.1 to 8.0 mol / l, nickel, iron, cobalt, chromium (III) ion total amount is 0.005 to 2.0 mol / l, at least one selected from lithium ion and sodium ion In which the concentration of at least one organic acid selected from carboxylic acid, hydroxycarboxylic acid, and amino acid is more than 5.0 equivalents to 15.0 equivalents with respect to the total metal ion concentration A method for forming a Re film by electroplating, comprising using a plating bath comprising an aqueous solution having a pH of 0 to 8 and a liquid temperature of 10 to 80 ° C. When the bath contains at least one ion selected from potassium, rubidium, cesium, calcium, strontium, and barium, the total amount of at least one selected from lithium ions and sodium ions in the bath is potassium, rubidium, 2. The method for forming a Re film by electroplating according to claim 1, wherein the amount is larger than the total amount of at least one ion selected from cesium, calcium, strontium, and barium. The composition of the alloy film to be formed is an atomic composition with Re of 98% or more, and the rest are Ni, Co, Fe, Mn, Cr, Mo, W, Nb, Ta, Hf, Si, Al, Ti, Mg, Pt The method for forming a Re film by electrolytic plating according to claim 1, wherein at least one selected from the group consisting of Ir, Rh, Au, Ag, P, B, C, Y, and Ce is an unavoidable impurity. . 2. The electroplated Re according to claim 1, wherein the bath contains sulfate ions of 0.0001 mol / l to 5.0 mol / l and chloride ions of 0.0001 mol / l to 5.0 mol / l. Method for forming a film.

Images