Plating film, composite film, sliding parts, method for manufacturing a plating film, method for manufacturing a composite film, and method for manufacturing sliding parts

Abstract

To provide a plating film that can improve corrosion resistance with nickel or nickel alloy plating film while providing a crystalline phosphoric acid salt at a surface of the plating film, and to provide a composite film, a slide component, a method for manufacturing a plating film, a method for manufacturing a composite film, and a method for manufacturing a slide component.SOLUTION: A plating film 13 provided at a surface or on a surface of a material to be plated 11 includes: a precipitated metal 14 including nickel or a nickel alloy; and a crystalline phosphoric acid salt particle 15 dispersed in the precipitated metal 14. The crystalline phosphoric acid salt particle 15 dispersed in the precipitated metal 14 includes a particle partially exposed from a surface of the precipitated metal 14.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a plating film containing nickel or a nickel alloy, a composite film containing the plating film, a sliding component provided with the composite film, a method for manufacturing the plating film, a method for manufacturing the composite film, and a method for manufacturing the sliding component.

Background Art

[0002] Nickel or nickel alloy plating in the field of surface treatment technology is used, for example, for the purpose of improving wear resistance, corrosion resistance, etc. Since nickel or nickel alloy plating is a metal, it has no sliding property by itself, but exhibits sliding property when combined with oil or a solid lubricant. As an example of a technique for improving the sliding property of a plating film, Patent Document 1 discloses a low-friction sliding member used in oil containing a strongly polar additive, and having a composite dispersion nickel plating layer containing at least one of particles or flakes of Y2O3, SiO2, Ta2O5, CeO2, MoO3 in a total volume ratio of 5 to 40% on the surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology described in Patent Document 1 is based on the premise of sliding in oil, so it is effective in environments with relatively low surface pressure, but its effect becomes limited as the surface pressure increases. When the surface pressure is relatively high, a technology that uses oils and fatty acid salts together with phosphate formed on the surface of the material by chemical conversion treatment (phosphate treatment) is effective. However, in the case of phosphate treatment, the material to be treated is limited to iron-based materials and is not generally applicable to non-iron-based materials. In addition, since the rust prevention effect of a phosphate-treated surface is lower than that of a surface plated with nickel or nickel alloy, it cannot be applied to parts where corrosion resistance is required. [Means for solving the problem]

[0005] A plating film for solving the above problems is a plating film provided on or on the surface of a material to be plated, comprising a deposited metal containing nickel or a nickel alloy, and crystalline phosphate particles dispersed in the deposited metal, wherein the dispersed crystalline phosphate particles include particles partially exposed on the surface of the deposited metal. With this configuration, it is possible to provide crystalline phosphate on the surface of the plating film while obtaining the effect of improving corrosion resistance by the deposited metal containing nickel or a nickel alloy.

[0006] A composite coating for solving the above problems comprises a plating film and a lubricating film provided on or on the surface of the plating film, wherein the lubricating film contains a fatty acid salt. With this configuration, a metal soap is formed by the reaction between the crystalline phosphate particles contained in the plating film and the fatty acid salt contained in the lubricating film. A composite coating with such a lubricating film can achieve both the effect of improved corrosion resistance due to precipitated metals containing nickel or nickel alloys and the effect of improved sliding properties due to the lubricating film.

[0007] A sliding part for solving the above problems is provided with the composite coating, wherein the surface of the composite coating is the surface that slides against the object to be slid. With the above configuration, by providing the surface of the sliding part with a composite coating comprising a plating film containing crystalline phosphate particles and a lubricating film containing a fatty acid salt, the corrosion resistance and sliding properties of the sliding part can be improved.

[0008] A method for manufacturing a plating film to solve the above problems involves using a plating solution in which nickel components are dissolved and crystalline phosphate particles are dispersed, and depositing a precipitated metal containing nickel or a nickel alloy derived from the nickel components onto the surface of the material to be plated by electroless plating or electroplating, thereby forming a plating film in which a portion of the crystalline phosphate particles are exposed on the surface of the precipitated metal. According to the above manufacturing method, a plating film containing crystalline phosphate particles on the surface can be provided for materials to which plating containing nickel or a nickel alloy can be applied. Therefore, compared to chemical conversion treatment, which is an example of a technique for forming phosphate on the surface of a material, this plating film can be applied to a wider variety of materials.

[0009] A method for manufacturing a composite film to solve the above problems involves forming the plating film on or on the surface of a material to be plated using the plating film manufacturing method, and then forming a lubricating film containing a fatty acid salt on or on the surface of the plating film.

[0010] A method for manufacturing sliding parts to solve the above problems involves forming the composite coating on or on the surface of a plated material that will become a sliding part, using the composite coating manufacturing method described above. [Effects of the Invention]

[0011] According to the present invention, corrosion resistance can be improved by a nickel or nickel alloy plating film while providing crystalline phosphate on the surface of the plating film. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic diagram showing the cross-sectional structure of a sliding part. [Modes for carrying out the invention]

[0013] One embodiment of the present invention will be described below with reference to Figure 1. [Sliding parts] As shown in Figure 1, the sliding parts 10 are components that make up, for example, an automobile engine or powertrain. Specifically, the sliding parts 10 are components that make up various industrial products such as engine pistons and cylinders, bearings, shafts as sliding shafts, plunger pumps, washers, etc.

[0014] The sliding part 10 comprises a plated material 11 having a smooth surface that is planar, curved, or spherical. The plated material 11 is a metallic material such as steel (including alloy steel), copper alloy, or aluminum alloy. However, the plated material 11 is not limited to metallic materials and may be a non-metallic material such as glass, ceramic, or resin.

[0015] A composite film 12 is provided on or on the surface of the material to be plated 11. The surface of the composite film 12 is a surface that slides against any sliding object. The composite film 12 comprises a plating film 13 located on or on the surface of the material to be plated 11, and a lubricating film 16 located on or on the surface of the plating film 13. Note that "the film is located on the 'surface' of the object" means that the film is arranged so as to be in contact with the surface of the object. Also, "the film is located on the 'surface' of the object" means that it is arranged with any layer (for example, an oxide film or an undercoat) interposed between the surface of the object and the film. In other words, "the film is located on or on the surface of the object" means that the film may be arranged so as to be in contact with the surface of the object, or any layer may be interposed between the surface of the object and the film. Figure 1 shows an example in which the composite film 12 is provided on the surface of the material to be plated 11.

[0016] [Plating film] The plating film 13 is a layer formed, for example, by electroless plating or electroplating. The plating film 13 comprises deposited metal 14 and crystalline phosphate particles 15 dispersed in the deposited metal 14. The deposited metal 14 includes nickel or a nickel alloy. The crystalline phosphate particles 15 are located inside and on the surface of the deposited metal 14. That is, the crystalline phosphate particles 15 dispersed in the deposited metal 14 include particles that are partially exposed on the surface of the deposited metal 14. The deposited metal 14, which includes nickel or a nickel alloy, is responsible for improving corrosion resistance and surface hardening in the composite film 12. The deposited metal 14 may also include an oxide film (nickel oxide) formed by the oxidation of the surface of the deposited metal 14. In this case, the surface of the plating film 13 is composed of an oxide film formed by the oxidation of the deposited metal 14.

[0017] The crystalline phosphate particles 15 contain a phosphoric acid component and a metal component. The phosphoric acid component is, for example, at least one selected from the group consisting of orthophosphate, phosphorous acid, and hypophosphorous acid, which are oxoacids of phosphorus, and pyrophosphate and tripolyphosphate, which are condensates of orthophosphate. The metal component is, for example, at least one selected from the group consisting of iron, zinc, calcium, magnesium, barium, manganese, titanium, and aluminum. The crystalline phosphate particles 15 are preferably insoluble or sparingly soluble in the plating solution and do not inhibit the plating reaction, and are, for example, at least one selected from the group consisting of zinc phosphate, zinc iron phosphate, zinc calcium phosphate, manganese phosphate, titanium phosphate, calcium phosphate, and condensed aluminum phosphate. The crystalline phosphate particles 15 may be anhydrous or hydrated. Here, "slightly soluble in the plating solution" means that the solubility in the plating solution is 0.05 g / 100 g or more and 0.1 g / 100 g or less. Furthermore, "insoluble in plating solution" here means that the solubility in the plating solution is less than 0.05 g / 100 g.

[0018] The plating solution used for forming the plating film 13 contains a nickel component that constitutes the deposited metal 14 and crystalline phosphate particles 15. The plating method for forming the plating film 13 is eutectic of the deposited metal 14 and the crystalline phosphate particles 15. The eutectic for forming the plating film 13 deposits the deposited metal 14 derived from the nickel component on the surface of the workpiece 11 while incorporating the crystalline phosphate particles 15 into the inside and surface of the deposited metal 14.

[0019] The shape of the crystalline phosphate particles 15 is not particularly limited as long as they are particles, and they may be any shape such as spherical, substantially spherical, rod-shaped, flake-shaped, plate-shaped, scaly, or a mixture thereof. The particle diameter of the crystalline phosphate particles 15 is preferably 20% or more and 200% or less in terms of the 50% particle diameter (median diameter D50) with respect to the required thickness of the plating film 13. By using the crystalline phosphate particles 15 having a particle diameter within the above range, the crystalline phosphate particles 15 can be preferably incorporated during the deposition of the deposited metal 14, and the crystalline phosphate particles 15 that are buried in the deposited metal 14 and do not expose on the surface of the deposited metal 14 can be reduced. As an example, the particle diameter (median diameter D50) of the crystalline phosphate particles 15 is 0.5 μm or more and 10 μm or less. The plating thickness of the plating film 13 is, for example, 3 μm or more and 30 μm or less, but it may also be less than 3 μm or more than 30 μm.

[0020] [Lubricating film] The lubricating film 16 is, for example, a layer formed by soap treatment. The lubricating film 16 includes an alkaline soap film 17 and a metal soap 18. The alkaline soap film 17 constitutes the outermost surface of the composite film 12. The metal soap 18 is located between the plating film 13 and the alkaline soap film 17.

[0021] The alkali soap film 17 contains a fatty acid salt. The fatty acid salt is a salt of a fatty acid and an alkali metal. The fatty acid is preferably a saturated or unsaturated fatty acid having 8 to 22 carbon atoms. The fatty acid is, for example, octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, ricinoleic acid, or 12-hydroxystearic acid. The alkali metal is, for example, sodium, potassium, or lithium. The fatty acid salt is at least one selected from the group consisting of combinations of the above fatty acids and alkali metals.

[0022] The metal soap 18 is formed by the reaction of the metal component contained in the crystalline phosphate particles 15 of the plating film 13 and the fatty acid contained in the fatty acid salt of the alkali soap film 17. The metal soap 18 is, for example, aluminum octylate, calcium laurate, zinc laurate, barium laurate, calcium myristate, zinc myristate, zinc palmitate, calcium stearate, zinc stearate, barium stearate, magnesium stearate, aluminum stearate, calcium ricinoleate, zinc ricinoleate, barium ricinoleate, calcium 12-hydroxystearate, zinc 12-hydroxystearate, magnesium 12-hydroxystearate, aluminum 12-hydroxystearate, and at least one selected from the group consisting of barium 12-hydroxystearate.

[0023] Note that the metal soap 18 may be formed in layers between the plating film 13 and the alkali soap film 17, or may be partially located so as to be distributed around the crystalline phosphate particles 15 partially exposed on the surface of the deposited metal 14.

[0024] The lubricating film 16 functions as a lubricant to enhance the slidability and contribute to the improvement of wear resistance. That is, the composite film 12 achieves both the effect of improving the corrosion resistance by the deposited metal 14 containing nickel or a nickel alloy and the effect of improving the slidability by the lubricating film 16.

[0025] [Method for manufacturing a sliding part] As a method for manufacturing the composite coating 12, first, a plating process is performed in which a plating film 13 is formed on or on the surface of the material to be plated 11 by an electroless plating method or an electroplating method. In the plating process, deposited metal 14 derived from the nickel component contained in the plating solution is deposited on or on the surface of the material to be plated 11, and crystalline phosphate particles 15 are incorporated into the surface and interior of the deposited metal 14 and co-deposit. Prior to the plating process, although not essential, it is preferable to remove oil and dirt adhering to the material to be plated by appropriately combining alkaline degreasing, acidic degreasing, electrolytic degreasing, pickling, solvent washing, deionized water washing, etc. Physical operations such as ultrasonic irradiation and agitation may also be performed. After pre-cleaning of the material to be plated 11, it is preferable to wash the surface of the material to be plated 11 with water so that no cleaning solution remains on the surface. After the plating process, the surface of the plating film 13 may be washed with water and dried so that no processing solution remains on the surface, or it is not necessary to dry it after washing with water. The following describes the plating solutions used in electroless plating and electroplating in the plating process.

[0026] [Electroless plating] The plating solution used in the electroless plating method contains crystalline phosphate particles 15, nickel components, a reducing agent, a complexing agent, and a pH adjuster. The amount of crystalline phosphate particles 15 added is, for example, 100 mg / L to 20,000 mg / L, preferably 500 mg / L to 10,000 mg / L, and more preferably 1,000 mg / L to 5,000 mg / L. The crystalline phosphate particles 15 are dispersed in the plating solution without being dissolved.

[0027] The nickel component used is a water-soluble nickel compound that is soluble in the plating solution. The water-soluble nickel compound is, for example, at least one selected from the group consisting of nickel sulfate, nickel chloride, nickel sulfamate, and nickel hypophosphite. Nickel sulfate is particularly preferred because of its good solubility in the plating solution. The concentration of the nickel component is, for example, 0.5 g / L to 50 g / L.

[0028] The reducing agent is, for example, at least one selected from the group consisting of hypophosphorous acid, hypophosphate (sodium salt, potassium salt, ammonium salt), dimethylamine borane, and hydrazine. The concentration of the reducing agent is, for example, 0.01 g / L or more and 100 g / L or less.

[0029] The complexing agent is, for example, at least one selected from the group consisting of monocarboxylic acids, dicarboxylic acids, hydroxycarboxylic acids, aminopolycarboxylic acids, ethylenediaminediacetic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, and their ammonium, potassium, and sodium salts. Examples of monocarboxylic acids are acetic acid or formic acid. Examples of dicarboxylic acids are malonic acid, succinic acid, adipic acid, maleic acid, or fumaric acid. Examples of hydroxycarboxylic acids are malic acid, lactic acid, glycolic acid, gluconic acid, or citric acid. Examples of aminopolycarboxylic acids are ethylenediaminetetraacetic acid or diethylenetriaminepentaacetic acid. Other complexing agents such as phosphonic acids or amino acids may also be used. The concentration of the complexing agent is, for example, 5 g / L to 180 g / L.

[0030] The pH adjusting agent is, for example, at least one selected from the group consisting of inorganic acids such as sulfuric acid and phosphoric acid, sodium hydroxide, and ammonia water. The pH range of the plating solution in electroless plating is, for example, 3.0 to 12.0, more preferably 4.0 to 9.0. The pH of the plating solution in electroless plating is, as an example, 4.3 to 6.3.

[0031] Furthermore, various additives may be added to the plating solution. An example of an additive is a stabilizer, which is at least one selected from the group consisting of lead salts such as lead nitrate and lead acetate, bismuth salts such as bismuth nitrate and bismuth acetate, and sulfur compounds such as thiodiglycolic acid and sodium thiosulfate. The amount of stabilizer added is, for example, 0.01 mg / L to 100 mg / L. An example of an additive is a pH buffer, which is at least one selected from the group consisting of boric acid, phosphoric acid, phosphorous acid, carbonic acid, their sodium salts, potassium salts, and ammonium salts. The amount of buffer added is, for example, 0.1 g / L to 200 g / L. An example of an additive is a surfactant, which is at least one selected from the group consisting of nonionic, cationic, anionic, or amphoteric surfactants. The amount of surfactant added is, for example, 0.1 mg / L to 100 mg / L.

[0032] [Electroplating] In the case of electroplating, plating solutions such as Watt baths and nickel sulfamate baths are used. These plating solutions contain nickel components in addition to crystalline phosphate particles 15. The amount of crystalline phosphate particles 15 added can be within the same numerical range as in electroless plating, even in the case of electroplating. Note that the crystalline phosphate particles 15 do not dissolve in the plating solution but exist dispersed in the plating solution.

[0033] In the case of a Watt bath, the nickel component is, for example, at least one selected from the group consisting of water-soluble nickel compounds such as nickel sulfate hexahydrate, nickel chloride hexahydrate, and nickel carbonate tetrahydrate. Among the water-soluble nickel compounds, nickel sulfate hexahydrate or nickel chloride hexahydrate is preferred in terms of its excellent deposition properties on the material to be plated 11, and a mixture of nickel sulfate hexahydrate and nickel chloride hexahydrate is more preferred. When using a mixture of nickel sulfate hexahydrate and nickel chloride hexahydrate as the nickel component, it is preferable that the amount of nickel sulfate hexahydrate added is 200 g / L or more and 500 g / L or less, and the amount of nickel chloride hexahydrate added is 70 g / L or less.

[0034] In the case of a nickel sulfamate bath, the nickel component is, for example, a water-soluble nickel compound such as nickel sulfamate, nickel chloride hexahydrate, or a mixture thereof. Furthermore, in the case of electroplating, the pH of the plating solution can be set between 3.5 and 5.0 in both the Watt bath and the nickel sulfamate bath.

[0035] Furthermore, various primary and secondary brighteners may be added to the plating solution. The primary brightener is, for example, at least one selected from the group consisting of saccharin, benzene such as sodium naphthalenesulfonate, derivatives of naphthalene, sulfonates, and sulfonamides. The secondary brightener is at least one selected from the group consisting of butynediol, propargyl alcohol, and coumarin.

[0036] [Method for controlling the amount of co-deposition of crystalline phosphate particles] Here, we will explain how to control the amount of crystalline phosphate particles 15 co-deposited onto the plating film 13 during the plating process. The amount of crystalline phosphate particles 15 co-deposited changes depending on the angle of the surface of the material to be plated 11 with respect to the surface of the plating solution. If we define 0 degrees as the state where the surface of the material to be plated 11 is facing upwards and parallel to the surface of the plating solution, and 90 degrees as the state where the surface of the material to be plated 11 is perpendicular to the surface of the plating solution, then the amount of crystalline phosphate particles 15 co-deposited decreases as the angle approaches 90 degrees from 0 degrees.

[0037] Furthermore, if the surface of the plating solution and the surface of the material to be plated 11 are parallel, precipitation of crystalline phosphate particles 15 and the like may occur, so it is preferable that the angle of the surface of the material to be plated 11 with respect to the surface of the plating solution be at least 0 degrees. Also, if the angle of the material to be plated 11 with respect to the surface of the plating solution is greater than 90 degrees, crystalline phosphate particles 15 may not co-deposit in the plating film 13, so it is preferable that the angle of the material to be plated 11 with respect to the surface of the plating solution be 90 degrees or less. Specifically, it is preferable that the angle of the material to be plated 11 with respect to the surface of the plating solution be between 15 degrees and 80 degrees.

[0038] On the surface of the plating film 13, the ratio of the area of ​​crystalline phosphate particles 15 to the total area of ​​deposited metal 14 is preferably 2% to 50%, and more preferably 4% to 42%. If the area ratio of crystalline phosphate particles 15 is within the above range, the corrosion resistance improvement effect and hardness improvement effect of the deposited metal 14, and the sliding effect of the metal soap 18 produced by the reaction of crystalline phosphate particles 15 with fatty acids can be suitably exhibited.

[0039] The area ratio of crystalline phosphate particles 15 on the surface of the plating film 13 can be determined, for example, from a scanning electron microscope (SEM) image (backscattered electron image) obtained by imaging the surface of the plating film 13 with an SEM. Alternatively, the area ratio of crystalline phosphate particles 15 on the surface of the plating film 13 can also be determined by detecting elements specific to the crystalline phosphate particles 15 using EDS instead of backscattered electron images.

[0040] [Soap treatment] After the plating process is completed, a soap treatment process is performed to form a lubricating film 16 on the surface of the material to be plated 11 or on the plated film 13 formed on the surface. Specifically, an aqueous solution in which a fatty acid salt is dissolved in a solvent consisting of water (e.g., deionized water) or an organic solvent is applied to the surface of the plated film 13 by methods such as brushing, dipping, or spraying. At this time, the fatty acid in the aqueous solution reacts with the crystalline phosphate particles 15 exposed on the surface of the plated film 13, forming a metallic soap 18 that covers the surface of the plated film 13. Subsequently, by evaporating the solvent, a lubricating film 16 is formed with the metallic soap 18 at the boundary between the plated film 13 and the alkaline soap film 17.

[0041] The concentration of the aqueous solution used in the soap treatment process is, for example, 10 g / L to 200 g / L, but can be determined according to the type of fatty acid salt used, reaction time, temperature, and other conditions. The temperature of the aqueous solution used in the soap treatment process is preferably, for example, 60 degrees Celsius to 90 degrees Celsius, from the viewpoint of increasing the reaction rate. The reaction time is, for example, 1 minute to 30 minutes, but can be determined appropriately according to the required thickness of the lubricating film 16. There are no particular restrictions on the method of evaporating the solvent, but examples include natural drying, reduced-pressure drying, convection-type heat drying (e.g., natural convection-type heat drying, forced convection-type heat drying), and radiant drying (e.g., near-infrared drying, far-infrared drying). A combination of these may also be used. By following the above procedure, a composite film 12 is formed on the material to be plated 11, thereby manufacturing the sliding part 10.

[0042] [Effects of the Embodiment] According to the above embodiment, the following effects can be obtained. (1) According to the configuration of the plating film 13, while providing crystalline phosphate particles 15 on the surface of the plating film 13, it is possible to obtain the effect of improving corrosion resistance and hardness due to the deposited metal 14 containing nickel or a nickel alloy.

[0043] (2) Chemical conversion treatment (phosphate treatment), which is one example of a technique for forming phosphates on the surface of a material, is mainly limited to iron-based materials. In this respect, a plating film 13 in which a portion of crystalline phosphate particles 15 are exposed on the surface of the deposited metal 14 can be applied to materials to which plating containing nickel or nickel alloys is applicable. Therefore, compared to chemical conversion treatment, the plating film 13 can be applied to a wider variety of materials.

[0044] (3) By forming a lubricating film 16 containing a fatty acid salt on or on the surface of a plating film 13 in which a portion of the crystalline phosphate particles 15 are exposed on the surface of the deposited metal 14, a metal soap 18 is formed between the plating film 13 and the alkaline soap film 17 by the reaction between the crystalline phosphate particles 15 and the fatty acid salt. With a composite film 12 having such a lubricating film 16, it is possible to achieve both the effect of improved corrosion resistance by the deposited metal 14 containing nickel or a nickel alloy and the effect of improved sliding properties by the lubricating film 16.

[0045] (4) By forming a composite coating 12 on the surface of the sliding part 10, which comprises a plating coating 13 containing crystalline phosphate particles 15 on its surface and a lubricating coating 16 containing a fatty acid salt, the corrosion resistance and sliding properties of the sliding part 10 can be improved.

[0046] (5) By setting the area ratio of crystalline phosphate particles 15 on the surface of the plating film 13 to 2% or more and 50% or less, the corrosion resistance improvement effect and hardness improvement effect of the deposited metal 14 and the sliding effect of the metal soap 18 can be suitably exhibited.

[0047] The above embodiment can be implemented with the following modifications. The lubricating film 16 can be changed to any material depending on the application of the sliding part 10. For example, instead of the lubricating film 16 containing fatty acid salts, a layer made of a solid lubricant containing a layered lattice structure may be provided. Examples of the layered lattice structure include molybdenum disulfide, tungsten disulfide, graphite, boron nitride, mica, etc. In this case, no reaction that would form a metal soap 18 will occur.

[0048] The plating film 13 may be applied to applications other than the sliding parts 10 by omitting the lubricating film 16. For example, instead of the lubricating film 16, various coatings may be applied to or on the surface of the plating film 13. In this case, the plating film 13 functions as a base for the coating.

[0049] If the mechanical strength and corrosion resistance of the plating film 13 are sufficient, the area ratio of crystalline phosphate particles 15 on the surface of the plating film 13 is not limited to 2% or more and 50% or less, but may be, for example, greater than 50%.

[0050] Various undercoat plating films may be provided between the material to be plated 11 and the plating film 13. In other words, the material to be plated 11 may have an undercoat plating film that serves as the base for the plating film 13. In this case, the surface of the material to be plated 11 is composed of the undercoat plating film. For example, if a nickel or nickel alloy plating film that is sufficiently thick relative to the particle size of the crystalline phosphate particles 15 is required, an undercoat plating film that does not contain the crystalline phosphate particles 15 but contains nickel or a nickel alloy may be provided. In this case, the mechanical strength and corrosion resistance of the plating film 13 can be further improved. Note that the undercoat plating film does not have to be the same type of plating film as the deposited metal 14.

[0051] [Examples] Examples 1 to 7 and Comparative Examples 1 to 4 are described below. Note that each example and comparative example is not limited to the embodiments described above.

[0052] [Substrate and pre-plating treatment] In Examples 1-7 and Comparative Examples 1-4, a 50mm x 50mm x 3.0mm thick cold-rolled steel sheet SPCC-SB (manufactured by Paltec Co., Ltd.) was used as the substrate. In addition, as a pre-processing step before plating, the substrate surface was cleaned in the following order: alkaline degreasing, deionized water washing, electrolytic degreasing, deionized water washing, pickling (17% hydrochloric acid), and deionized water washing.

[0053] [Example 1] The substrate was immersed in an electroless plating solution stirred with a stirrer, and electroless plating was performed at 90°C until a film thickness of approximately 5 μm was achieved. At this time, the angle of the surface of the material to be plated with respect to the surface of the plating solution was set to 45 degrees. After the plating treatment, the sample was washed with water and dried to prepare the first and second test pieces. As the plating solution, a medium-high phosphorus type electroless nickel plating solution "SE-666" (manufactured by Nippon Kanigen Co., Ltd.) was used with 4.0 g / L of manganese phosphate particles "PL-55A" (manufactured by Nippon Parkerizing Co., Ltd.) added.

[0054] Next, the second test specimen was treated with soap using Palub 235 (manufactured by Nippon Parkerizing Co., Ltd.). Palub 235 is a soap treatment agent mainly composed of sodium stearate, an example of a fatty acid salt. The soap treatment conditions were as follows: the test specimen was immersed for 2 minutes in an 80°C aqueous solution to which 70 g / L of Palub 235 had been added, and then allowed to air dry.

[0055] [Example 2] Electroless plating was performed in the same manner as in Example 1, except that 2.0 g / L of manganese phosphate particles were added instead of 4.0 g / L of manganese phosphate particles. After plating, the sample was washed with water and dried to prepare a first test piece and a second test piece. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0056] [Example 3] Electroless plating was performed in the same manner as in Example 1, except that 2.5 g / L of titanium phosphate particles (manufactured by Fujimi Incorporated) were added instead of 4.0 g / L of manganese phosphate particles. After plating, the sample was washed with water and dried to prepare the first and second test pieces. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0057] [Example 4] Electroless plating was performed in the same manner as in Example 1, except that 1.5 g / L of condensed aluminum phosphate particles "K-WHITE#84" (manufactured by Teika Co., Ltd.) was added instead of 4.0 g / L of manganese phosphate particles. After plating, the sample was washed with water and dried to prepare the first and second test pieces. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0058] [Example 5] A Watt bath was prepared by adding 0.5 g / L of manganese phosphate particles "PL-55A" (manufactured by Nippon Parkerizing Co., Ltd.). The substrate was then immersed in the Watt bath while stirring it with a stirrer. The Watt bath contained 280 g / L of nickel sulfate, 40 g / L of nickel chloride, and 20 g / L of boric acid, and the pH was adjusted to 4.5. In this state, the current density was 2 A / dm² at 50°C. 2 The samples were electroplated using DC electrolysis until a film thickness of approximately 5 μm was achieved. At this time, the angle of the surface of the material to be plated relative to the surface of the plating solution was set to 45 degrees. After that, the plated samples were washed with water and dried to prepare the first and second test pieces. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0059] [Example 6] Electroplating was performed in the same manner as in Example 5, except that 1.0 g / L of zinc tetrahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., for chemical use) was added instead of 0.5 g / L of manganese phosphate particles. After the plating treatment, the sample was washed with water and dried to prepare the first and second test pieces. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0060] [Example 7] Electroplating was performed in the same manner as in Example 5, except that 3.0 g / L of tricalcium phosphate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., for chemical use) was added instead of 0.5 g / L of manganese phosphate particles. After the plating treatment, the sample was washed with water and dried to prepare the first and second test pieces. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0061] [Comparative Example 1] Electroless plating was performed in the same manner as in Example 1, except that dispersed particles were not added to the plating solution. After the plating treatment, the sample was washed with water and dried to prepare a first test piece and a second test piece. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0062] [Comparative Example 2] Except for not adding dispersed particles to the Watt bath, electroless plating was performed in the same manner as in Example 5. After plating, the sample was washed with water and dried to prepare the first and second test pieces. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0063] [Comparative Example 3] Electroless plating was performed in the same manner as in Example 1, except that 2.0 g / L of yttrium oxide particles (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 99.99%) were added instead of 4.0 g / L of manganese phosphate particles. After plating, the sample was washed with water and dried to prepare the first and second test pieces. Then, the second test piece was subjected to soap treatment in the same manner as in Example 1.

[0064] [Comparative Example 4] A chemical conversion treatment (phosphate treatment) was performed on the substrate to precipitate phosphate on the substrate surface. Prior to the chemical conversion treatment, surface preparation was carried out using alkaline degreasing, deionized water washing, and the surface conditioning agent "Preparen 55" (manufactured by Nippon Parkerizing Co., Ltd., 0.2% aqueous solution). For the chemical conversion treatment following the prior steps, "Parphos M1A" (manufactured by Nippon Parkerizing Co., Ltd., 14% aqueous solution) containing manganese phosphate was used as the treatment solution. In the chemical conversion treatment, the substrate was immersed in the treatment solution at 98°C for 10 minutes to precipitate a manganese phosphate film on the substrate, thereby preparing the first and second test specimens. The weight of the manganese phosphate film at this time was 6.4 g / m². 2 The second test specimen was then treated with soap, similar to the procedure in Example 1.

[0065] [Area ratio measurement of crystalline phosphate particles] For the first test specimens in Examples 1-7 and Comparative Examples 1-4, SEM images obtained using a scanning electron microscope (SEM) were observed on the plated or chemically converted substrate surface. In Examples 1-7, the ratio of the area of ​​crystalline phosphate particles 15 to the sum of the area of ​​deposited metal 14 and the area of ​​crystalline phosphate particles 15 on the surface of the plated film 13 was measured from the acquired SEM images. In Comparative Example 3, the ratio of the area of ​​yttrium oxide particles to the sum of the area of ​​deposited metal 14 and the area of ​​yttrium oxide particles on the surface of the plated film 13 was measured from the acquired SEM images. In Comparative Example 4, the ratio of the area occupied by the manganese phosphate film on the substrate surface was measured. The measurement results of the area ratios for each sample are shown in Table 1.

[0066] [Corrosion resistance evaluation] For Examples 1-7 and Comparative Examples 1, 2, and 4, the surface of the first test piece was scratched with a utility knife, and a salt spray test (JIS Z2371) was performed for 3 hours. After that, the corrosion resistance was evaluated based on the degree of rust formation on the iron, which was the base material. A sample was classified as poor (×) if rust was observed on the entire surface, both in the scratched area and the non-scratched area. A sample was classified as average (△) if rust was observed from the scratched area and partially from the non-scratched area. A sample was classified as good (〇) if rust was observed only in the scratched area. A sample was classified as best (◎) if only slight rust was observed only in the scratched area. The results of the corrosion resistance evaluation are shown in Table 1.

[0067] [Sliding performance evaluation] For Examples 1-7 and Comparative Examples 1-4, the sliding properties of the second test specimen were evaluated using the ball-on-disk method. The friction test conditions for the ball-on-disk method involved rotating a 10mm diameter SUJ2C sphere on the test specimen under a load of 19.6N, a sliding circle diameter of 10mm, and a rotation speed of 300rpm. The frictional force during rotation was measured. The evaluation method assessed the sliding properties based on the time it took for the friction coefficient μ, calculated from the frictional force, to exceed 0.1. A time of less than 2000 seconds for the friction coefficient μ to exceed 0.1 was classified as poor (×), 2000 seconds or more but less than 4000 seconds as average (△), 4000 seconds or more but less than 6000 seconds as good (〇), and 6000 seconds or more as best (◎). The evaluation results for sliding properties are shown in Table 1.

[0068] [Table 1]

[0069] As shown in Table 1, in Examples 1 to 7, the area ratio of crystalline phosphate particles 15 on the surface of the plating film 13 was between 4% and 42%. In Comparative Examples 1 and 2, since no dispersed particles were present in the plating film 13, the ratio was set to 0%. In Comparative Example 3, the area ratio of yttrium oxide particles on the surface of the plating film 13 was approximately 20%. In Comparative Example 4, since a manganese phosphate film was deposited over the entire surface of the substrate, the evaluation result was set to 100% even though it was not particulate.

[0070] In the corrosion resistance evaluation, rusting was observed only from the defective areas in Examples 1-7 and Comparative Examples 1 and 2. In contrast, rusting was observed across the entire surface of the substrate in Comparative Example 4. Therefore, it was confirmed that even when crystalline phosphate particles 15 are present on the surface of the plating film 13, the corrosion resistance is improved by the rust-preventive effect of the deposited metal 14, which consists of nickel or a nickel alloy, in the plating film 13.

[0071] In the evaluation of sliding properties, Examples 1-7 and Comparative Example 4 showed superior sliding properties compared to Comparative Examples 1-3. Therefore, it was confirmed that the crystalline phosphate particles 15 present on the surface of the plating film 13 react with the soap treatment to form a metal soap 18, contributing to the improvement of sliding properties. From the above, it was confirmed that by applying a soap treatment to a plating film 13 in which crystalline phosphate particles 15 are dispersed in the deposited metal 14, it is possible to achieve both the rust prevention effect of the deposited metal 14 and the sliding property improvement effect of the metal soap 18. [Explanation of Symbols]

[0072] 10…Sliding parts 11…Material to be plated 12…Composite coating 13…Plating film 14...Precipitated metal 15...Crystalline phosphate particles 16… Lubricating film 17…Alkaline soap film 18…Metal soap

Claims

1. A plating film provided on or on the surface of a material to be plated, Precipitated metals containing nickel or nickel alloys, The system comprises crystalline phosphate particles dispersed in the precipitated metal, The dispersed crystalline phosphate particles include particles that are partially exposed on the surface of the precipitated metal. The area ratio of the crystalline phosphate particles on the surface of the plating film is 4% or more and 42% or less. Plating film.

2. The plating film according to claim 1, The plated film comprises a lubricating film provided on or on the surface of the plated film, The lubricating film contains a fatty acid salt. Composite coating.

3. A plating film provided on or on the surface of a material to be plated, The plated film comprises a lubricating film provided on or on the surface of the plated film, The aforementioned plating film comprises a deposited metal containing nickel or a nickel alloy, and crystalline phosphate particles dispersed in the deposited metal. The dispersed crystalline phosphate particles include particles that are partially exposed on the surface of the precipitated metal. The lubricating film contains a fatty acid salt. Composite coating.

4. The composite coating comprises the one described in claim 2 or 3, The surface of the composite coating is the surface that slides against the object to be slid. Sliding parts.

5. The method involves using a plating solution in which nickel components are dissolved and crystalline phosphate particles are dispersed, and depositing a deposited metal containing nickel or a nickel alloy derived from the nickel components onto the surface of the material to be plated by electroless plating or electroplating, thereby forming a plating film on the surface of the deposited metal in which a portion of the crystalline phosphate particles are exposed. The area ratio of the crystalline phosphate particles on the surface of the plating film is 4% or more and 42% or less. A method for manufacturing a plated film.

6. After forming the plating film on or on the surface of a material to be plated using the method for manufacturing a plating film according to claim 5, a lubricating film containing a fatty acid salt is formed on or on the surface of the plating film. A method for manufacturing a composite coating.

7. Using a plating solution in which nickel components are dissolved and crystalline phosphate particles are dispersed, a plated film is formed in which a portion of the crystalline phosphate particles are exposed on the surface of the plated material by electroless plating or electroplating, thereby depositing a deposited metal containing nickel or a nickel alloy derived from the nickel components onto the surface of the plated material. This includes forming a lubricating film containing a fatty acid salt on or on the surface of the plated film after the aforementioned plating film has been formed. A method for manufacturing a composite coating.

8. Using the method for manufacturing a composite coating described in claim 6 or 7, the composite coating is formed on or on the surface of a plated material that will become a sliding part. A method for manufacturing sliding parts.

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