Surface treatment method for sliding parts

Abstract

To provide a surface processing method for a slide member having excellent frictional properties with a simple manner.SOLUTION: A surface processing method for a slide member 10 including a texture by a laminate part 22 laminated on a surface of a base material 11, has a step of jetting a material of the laminate part 22 with a pattern of the texture to form the laminate part 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a surface treatment method for a slide member and a slide member. [Background technology]

[0002] Patent Document 1 discloses a movable scroll having a floating island-shaped pressure-receiving portion, which is formed by high-precision casting using a mold made of a mixture of sand and a special resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-219809 Summary of the Invention [Problem to be solved by the invention]

[0004] Attempts have been made to reduce frictional resistance by applying texture to the surface of a sliding member. However, when forming the texture by casting, as in the method disclosed in Patent Document 1, a special mold must be prepared, making the manufacture of the sliding member complicated. Furthermore, the method disclosed in Patent Document 1 has a low degree of freedom in the shape of the texture, leaving room for improvement in terms of reducing frictional resistance.

[0005] The present invention has been made in view of the above-mentioned conventional circumstances, and an object to be achieved by the present invention is to provide a surface processing method for a slide member, which can provide a slide member having good friction characteristics by a simple method, and to provide such a slide member. [Means for solving the problem]

[0006] The surface processing method for a sliding member is a method for processing a surface of a sliding member having a texture formed by a laminated portion laminated on the surface of a base material, and includes a step of spraying a material for the laminated portion in a pattern of the texture to form the laminated portion.

[0007] According to the above-described method for surface treatment of a sliding member, a sliding member having good friction characteristics can be provided by a simple method. [Brief explanation of the drawings]

[0008] [Figure 1] 1A is a plan view of the texture according to embodiment 1. FIG. 1B is a cross-sectional view taken along line BB. [Figure 2] 10A to 10C are explanatory views for explaining a surface processing method for a sliding member. [Figure 3] 1 shows an image of the laminated portion observed with a confocal laser microscope. [Figure 4] FIG. 10 is an explanatory diagram for explaining the lubricating oil drawing action. [Figure 5] FIG. 10 is an explanatory view for explaining a surface processing method for a slide member according to a second embodiment. [Figure 6] 1 shows an image of the laminated portion observed with a confocal laser microscope. [Figure 7] FIG. 10 is an explanatory view for explaining a surface processing method for a slide member according to a third embodiment. [Figure 8] 10A and 10B are cross-sectional views of a laminated part according to another embodiment. [Figure 9] 1A is a plan view of a texture according to another embodiment, and FIG. [Figure 10] 10A to 10C are plan views of textures according to other embodiments. [Figure 11] FIG. 10 is an explanatory view for explaining a surface processing method for a slide member according to a fifth embodiment. [Figure 12] FIG. 10 is an explanatory view for explaining a surface processing method for a slide member according to a sixth embodiment. [Figure 13] 1A is a cross-sectional view of a texture according to embodiment 7. FIG. 1B to FIG. 1D are diagrams schematically showing the gradient composition of the textures according to embodiments 5 to 7. [Figure 14] FIG. 13 is an explanatory view for explaining a surface processing method for a slide member according to an eighth embodiment. [Figure 15] 1 shows optical microscope images of the disks of Examples 1 and 2. [Figure 16] 1 is a graph showing the change over time in the coefficient of friction according to Example 1 and Example 2. [Figure 17] 1 shows optical microscope images and cross-sectional curves of the sliding surfaces of Examples 1 and 2 after testing. [Figure 18] 10 is an optical microscope image of the disks of Examples 3 and 4. [Figure 19] 1 is a graph showing the change over time in the coefficient of friction in Examples 2 to 4. [Figure 20] 10 shows optical microscope images and cross-sectional curves of the sliding surfaces of Examples 3 and 4 after testing. [Figure 21] 10 shows optical microscope images of the disks of Examples 5 and 6. [Figure 22] 1 is a graph showing the change in friction coefficient over time in Examples 3 to 6. [Figure 23] 10 shows optical microscope images and cross-sectional curves of the sliding surfaces of Examples 5 and 6 after testing. DETAILED DESCRIPTION OF THE INVENTION

[0009] A preferred embodiment of the present invention will now be described. The surface processing method for a sliding member described above may include a step of disposing particles on the surface of the substrate before the step of forming the laminated portion, and the step of forming the laminated portion may include spraying a material for the laminated portion onto the particles to form the laminated portion with the particles embedded. This method makes it possible to form a laminated portion with embedded particles, and to impart desired properties to the sliding surface depending on the properties of the particles.

[0010] In the method for surface treatment of a sliding member, the particle size of the particles is preferably at least half the thickness of the laminated portion and is not more than 100 μm. This configuration makes it easy to realize a structure in which some of the particles are exposed from the laminated portion.

[0011] In the surface treatment method for a sliding member, the particles are preferably one or more selected from the group consisting of particles of solid lubricants, abrasives, and biocompatible materials. By using these particles, desired properties can be imparted to the sliding surface.

[0012] The step of forming the laminated portion may include spraying the material of the laminated portion in the pattern of the texture to form a first layer of the laminated portion, and spraying the material of the laminated portion on top of the first layer to form a second layer of the laminated portion. This configuration allows the height of the laminated portion to be increased compared to when the laminated portion has a single-layer structure. As a result, the texture shape can be optimized to achieve the desired sliding characteristics.

[0013] The sliding member may include a base layer that serves as a base for the laminated portion, and may include a step of forming the base layer by spraying a material for the base layer in a fill pattern onto the surface of the base material before the step of forming the laminated portion. With this configuration, the shape of the laminated portion can be maintained, and desired sliding characteristics can be maintained for a long period of time.

[0014] The substrate may be a metal substrate having a plurality of holes scattered on its surface, and a step of forming the plurality of holes by electropolishing may be performed before the step of forming the laminated portion. With this configuration, the material of the laminated portion or the material of the base layer may penetrate into the plurality of holes and solidify, thereby achieving an anchor effect. Therefore, the shape of the laminated portion can be maintained, and the desired sliding characteristics can be maintained for a long period of time.

[0015] The substrate may be a metal substrate, and the sliding member may have exposed portions of the substrate that are not covered by the laminated portion. The surface processing method for the sliding member may include a step of electropolishing the portions of the substrate surface that are not covered by the laminated portion. According to this configuration, the electropolishing can make the portions of the substrate surface that are not covered by the laminated portion recessed relative to the portions that were covered by the laminated portion. Therefore, even if the laminated portion wears, an oil reservoir can be formed due to the uneven shape of the substrate surface.

[0016] The substrate may be a metal substrate, and the substrate may be exposed in a portion of the sliding member that is not covered by the laminated portion. The surface processing method for the sliding member may include a step of plating the portion of the substrate surface that is not covered by the laminated portion. According to this configuration, by forming a metal coating on the portion of the substrate surface that is not covered by the laminated portion, it is possible to intentionally make the surface of the sliding member non-uniform. This makes the rigidity of the contact portion with the mating material non-uniform, which produces an oil film retention effect and further expands the control range of friction characteristics.

[0017] The substrate may be a metal substrate, and the sliding member may have exposed portions of the substrate not covered by the laminated portion. The method may further include a step of projecting particles onto the surface of the substrate after the laminated portion is formed to modify the portions not covered by the laminated portion. According to this configuration, by modifying the portions of the substrate surface not covered by the laminated portion, it is possible to intentionally make the surface of the sliding member non-uniform. This results in non-uniform rigidity at the contact portion with the mating material, which produces an oil film retention effect and further expands the control range of friction characteristics.

[0018] The sliding member of the present invention is preferably a sliding member processed by the above-mentioned method. According to this configuration, a sliding member having good friction characteristics can be obtained by a simple method.

[0019] The surface treatment methods for slide members and slide members according to the first to fifth embodiments will be described in detail below.

[0020] <Embodiment 1> 1. Surface treatment method for sliding member 10 This embodiment is a surface processing method for a slide member 10 having a texture 20 made of a laminated portion 22 laminated on the surface of a substrate 11. The surface processing method for the slide member 10 includes a step of spraying a material 23 for the laminated portion 22 in the pattern of the texture 20 to form the laminated portion 22.

[0021] (1) Sliding member 10 1 and 4, the sliding member 10 has a sliding surface 10A that slides against a sliding surface 50A of a mating member 50. The sliding surface 10A is based on a flat surface of the sliding member 10. Lubricating oil LO is present between the sliding surface 10A of the sliding member 10 and the sliding surface 50A of the mating member 50. The sliding surface 50A of the mating member 50 is based on a flat surface parallel to the sliding surface 10A of the sliding member 10. From the viewpoint of improving friction characteristics, it is preferable that the sliding surface 50A of the mating member 50 is a surface that comes into planar contact with the sliding surface 10A rather than a surface that comes into point contact with the sliding surface 10A, such as a spherical surface.

[0022] The slide member 10 includes a substrate 11 and a laminated portion 22. The material of the substrate 11 is not particularly limited, but a metal is preferable. Examples of materials for the substrate 11 include iron-based metals, titanium-based metals, stainless steel-based metals, zinc-based metals, aluminum-based metals, magnesium-based metals, and nickel-based metals. The metal may be a pure metal or an alloy containing two or more metal components. Among these, from the viewpoint of versatility, iron-based metals such as carbon steel (S45C) and cast iron (FC250, FCD450), aluminum alloys (5052, 5056, 5083, 6061, 6063, 2014, 2017, 2024, 2628, 7N01, 7075, 4032), aluminum alloy castings (AC8A, AC4B), copper alloys, superalloys, etc. are preferable. When used as a biocompatible sliding member such as an artificial joint, titanium, stainless steel, cobalt chromium alloy metals, and ceramics such as zirconia and alumina may be used from the viewpoint of corrosion resistance and biocompatibility.

[0023] The material of the laminated portion 22 is not particularly limited. The material 23 of the laminated portion 22 is preferably a curable material. Examples of the curable material include resin materials such as ultraviolet curable resin materials and thermosetting resin materials. UV curable resin materials are desirable because they are easy to cure, have a faster curing rate than other materials, and are easy to handle. The curable material is not limited to these, and curable materials that cure with moisture, oxygen, etc. may also be used. Examples of "ultraviolet curable resins" that are cured products of ultraviolet curable materials include acrylic resins, methacrylic resins, urethane resins, polyester resins, maleimide resins, epoxy resins, oxetane resins, polyether resins, polyvinyl ether resins, polyamideimide resins, and polyimide resins.

[0024] (2) Texture 20 As shown in FIG. 1, the texture 20 is composed of laminated portions 22 laminated on the surface of the substrate 11. Specifically, the texture 20 has the laminated portions 22 in the form of floating islands and recessed portions 21 surrounding the laminated portions 22. A plurality of laminated portions 22 are provided. The recessed portions 21 have a continuous shape. The texture 20 of this embodiment is a so-called convex texture.

[0025] The multiple laminated portions 22 constitute a pressure-receiving surface that receives surface pressure. The laminated portions 22 are substantially circular in plan view. The upper surface of the laminated portions 22 is substantially flat. The side surfaces of the laminated portions 22 may be substantially perpendicular to the surface of the substrate 11, or may be inclined inward from the surface of the substrate 11 upward in order to reduce the coefficient of friction. The area ratio of the multiple laminated portions 22 is not particularly limited, but is preferably larger than the area ratio of the recessed portions 21. The height of the laminated portions 22 is, for example, 1 μm or more and 100 μm or less. The height of the laminated portions 22 can be controlled by appropriately adjusting the viscosity of the material 23 of the laminated portions 22 or the number of times the material 23 of the laminated portions 22 is laminated. The laminated portion 22 of this embodiment has a single-layer structure in which the material 23 of the laminated portions 22 is laminated once.

[0026] From the viewpoint of reducing and stabilizing the coefficient of friction, when the convex portion is substantially circular in plan view, the ratio of the height of the convex portion to the diameter of the convex portion (height of the convex portion / diameter of the convex portion) is preferably 1 / 10,000 or more and 1 / 100 or less. A convex portion having a substantially circular shape in plan view may include, for example, a shape tapering in one direction, an elliptical shape, etc., in addition to a perfect circle shape in plan view. In the case of a shape other than a perfect circle, the diameter of the convex portion can be determined by calculating the diameter of an area-equivalent circle from the area of ​​the convex portion in plan view.

[0027] Figure 3 shows an image of an example of a single-layer laminated section observed with a confocal laser microscope. This laminated section was formed using an inkjet printer (Birdland Machine LLC, model number: FSA3UV) and ink (laminated section material, Zhuhai Huacai New Materials Technology Co., Ltd., model number: Industrial Printers Serials UV INK FOR EPSON-BLACK). The black ink preferably contains carbon black as a pigment. Therefore, the inclusion of carbon black in the laminated section 22 is expected to improve sliding properties. The texture pattern was dotted. The substrate was made of carbon steel (S45C). The substrate surface was primarily flat. The diameter of the formed laminated section was approximately 1000 μm, and the height of the laminated section was approximately 5 μm. The side of the laminated section was inclined relative to the surface of the substrate. The inclination angle of the side of the laminated section is presumably determined by the contact angle between the ink droplet and the surface of the substrate.

[0028] The recesses 21 form oil reservoirs in which the lubricating oil LO is stored. The recesses 21 are groove-shaped and surround the entire periphery of the laminated portions 22. The recesses 21 are formed in a mesh-like shape with the grooves surrounding each of the multiple laminated portions 22 communicating with each other. The substrate 11 is exposed at the bottom of the recesses 21.

[0029] (3) Surface processing method The surface processing method for the slide member 10 includes a step of spraying material 23 for the laminated portion 22 in the pattern of the texture 20 to form the laminated portion 22. Specifically, the surface processing method for the slide member 10 includes a spraying step and a curing step. Hereinafter, the method will be described with reference to FIG. 2.

[0030] In the spraying process, the material 23 of the laminated portion 22 is sprayed directly onto the surface of the substrate 11 by inkjet printing. The spraying process can be performed using a general-purpose inkjet printer. From the viewpoint of realizing a fine texture shape, a device having a printing resolution of 600 DPI or more, more preferably 1440 DPI or more, is suitable for the spraying process. The upper limit of the printing resolution of the device is not particularly limited, but from the viewpoint of using a general-purpose device, the printing resolution can be 9600 DPI or less. The pattern of the texture 20 can be designed as appropriate, and an example is a dot pattern having a predetermined diameter. In the spraying process, droplets of the material 23 of the laminated portion 22 are landed on the surface of the substrate 11 at the location where the laminated portion 22 is to be formed. The landed droplets of the material 23 of the laminated portion 22 wet and spread, forming a substantially flat upper surface.

[0031] In the curing step, the ultraviolet curable resin material sprayed onto the surface of the substrate 11 is irradiated with ultraviolet light to cure it and form the laminated portion 22. The curing step, as well as the spraying step, can be performed using a general-purpose inkjet printer. The conditions for irradiating ultraviolet light are not particularly limited as long as the ultraviolet curable resin material is irreversibly cured.

[0032] 2. Actions and Effects of the Present Embodiment According to the surface processing method for the slide member 10 of this embodiment, a slide member 10 having good friction characteristics can be manufactured by a simple method. In designing the texture 20, it is necessary to optimize the pattern of the texture 20 and the height of the convex portions. According to the surface processing method for the slide member 10 of this embodiment, it is also possible to easily create a plurality of samples having different patterns of the texture 20 and different heights of the convex portions. Then, a sliding test is performed on each sample, and a texture 20 having the desired friction characteristics can be obtained.

[0033] It is presumed that the reason why the texture 20 can contribute to improving the friction characteristics of the sliding member 10, particularly to reducing the coefficient of friction, is due to the friction-reducing action of the texture 20. The action of drawing in the lubricating oil LO in the friction-reducing action of the texture 20 will be explained below. However, the present invention is not limited to these action mechanisms in any way.

[0034] In order to reduce friction during sliding between sliding members, it is desirable to reduce the frequency of solid-state contact. As shown in FIG. 4, the sliding member 10 of this embodiment exhibits an oil film retention effect due to the generation of dynamic pressure caused by the lubricating oil LO in the recesses 21 being drawn into the upper surfaces of the laminated portions 22 of the laminated portions 22. Note that in FIG. 4, the arrows indicate the flow of the lubricating oil LO. Furthermore, with a configuration having multiple laminated portions 22 (convex texture), the recesses 21 can form a mesh-like flow path for the lubricating oil LO compared to, for example, a configuration having multiple recesses 21 (concave texture). This improves the circulation of the lubricating oil LO within the recesses 21 during sliding, allowing the lubricating oil LO to be constantly supplied to the upper surfaces of the laminated portions 22, thereby suppressing oil film breakdown. It is presumed that these effects reduce the frequency of contact between the sliding member 10 and the mating member 50 and reduce the friction coefficient. Furthermore, with the sliding member 10 of this embodiment, the recesses 21 are also expected to trap wear debris. In the case of the convex texture, the recesses 21 have a continuous shape, so that wear powder can be discharged to the outside of the sliding surface 10A together with the flowing lubricating oil LO.

[0035] In this embodiment, such a convex texture can be obtained by spraying the material 23 of the laminated portion 22 in the pattern of the texture 20 to form the laminated portion 22, rather than by conventional casting. The technique of spraying the material 23 of the laminated portion 22 allows the shape, size, and pitch of the laminated portion 22 to be appropriately adjusted to form an optimal texture 20. Furthermore, the technique of spraying the material 23 of the laminated portion 22 allows the height of the laminated portion 22 to be easily adjusted by adjusting the viscosity of the material 23 of the laminated portion 22 or the number of layers of the material 23 of the laminated portion 22. Furthermore, the wetting and spreading action of the material 23 of the laminated portion 22 ensures the flatness of the upper surface of the laminated portion 22, allowing the laminated portion 22 to be formed with good oil film retention. Thus, the technique of spraying the material 23 of the laminated portion 22 in the pattern of the texture 20 allows a sliding member 10 with high flexibility in the shape of the texture 20 and excellent friction characteristics to be obtained.

[0036] <Embodiment 2> The surface processing method for the slide member 110 according to the second embodiment differs from that of the first embodiment in the step of forming the laminated portion 122. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The following description will be given with reference to FIGS. 5 and 6.

[0037] The laminated portion 122 has a multi-layer structure. The laminated portion 122 has a first layer 22A laminated on the surface of the base material 11 and a second layer 22B laminated on the surface of the first layer 22A. The second layer 22B has approximately the same shape and size as the first layer 22A. Specifically, the second layer 22B and the first layer 22A are approximately circular in plan view and have approximately the same diameter. The second layer 22B is laminated on the first layer 22A with the center position aligned with that of the first layer 22A. The first layer 22A and the second layer 22B overlap each other over almost the entire area. The height of the laminated portion 122 is, for example, 1 μm or more and 100 μm or less.

[0038] In the surface processing method for the slide member 110, in the step of forming the laminated portion 122, the material 23 for the laminated portion 122 is sprayed in the pattern of the texture 20 to form a first layer 22A of the laminated portion 122, and the material 23 for the laminated portion 122 is sprayed on top of the first layer 22A to form a second layer 22B of the laminated portion 122. Specifically, the surface processing method for the slide member 110 includes a first spraying step, a first curing step, a second spraying step, and a second curing step. Unless otherwise specified, each of the first spraying step and the second spraying step can be performed in the same manner as the spraying step in the first embodiment. In the second spraying step in this embodiment, the material 23 for the laminated portion 122 is sprayed in a pattern having the same shape and size as the first spraying step, and at the same position as the first spraying step. Unless otherwise specified, each of the first curing step and the second curing step can be performed in the same manner as the curing step in the first embodiment.

[0039] Figure 6 shows an image of an example of a two-layer laminated section observed with a confocal laser microscope. This laminated section was created using an inkjet printer (Birdland Machine LLC, model number: FSA3UV) and ink (laminated section material, Zhuhai huacai New Materials Technology Co., Ltd., model number: Industrial Printers serials UV INK FOR EPSON - BLACK and WHITE) to form a first layer of white ink and a second layer of black ink. White ink tends to peel less from the substrate than black ink. Therefore, using white ink for the first layer is expected to suppress peeling of the laminated section 122 and maintain the shape of the laminated section 122. The texture pattern was a dot pattern with a diameter of 800 μm. Both the first and second layers were printed with the same pattern, overlapping each other. The substrate was made of carbon steel (S45C). The surface of the substrate was primarily flat. The formed laminate had a diameter of about 800 μm and a height of about 10 μm, and the side surfaces of the laminate were inclined relative to the surface of the substrate.

[0040] According to this embodiment, the height of the laminated portion 122 can be increased compared to when the laminated portion has a single-layer structure. As a result, the shape of the texture 20 can be optimized to achieve desired sliding characteristics.

[0041] <Embodiment 3> The surface processing method for the sliding member 210 according to the third embodiment differs from that of the first embodiment in that it includes a step of arranging particles 30 on the surface of the substrate 11 before the step of forming the laminated portion 222. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The following description will be given with reference to FIG. 7.

[0042] The surface processing method for the slide member 210 includes a particle arrangement step, a spraying step, a hardening step, and a cleaning step. The cleaning step is an optional step. Unless otherwise specified, the spraying step and the hardening step can be performed in the same manner as the spraying step and the hardening step in the first embodiment.

[0043] The particles 30 are preferably one or more selected from the group consisting of solid lubricants, abrasives, and particles of biocompatible materials. Examples of solid lubricants include one or more solid lubricants selected from the group consisting of soft metals, graphite, fullerenes, carbon nanotubes, Teflon (registered trademark) (tetrafluoroethylene), molybdenum disulfide, hexagonal boron nitride, fluorocarbons, and metal sulfides. When the particles 30 are solid lubricants, they are expected to reduce the coefficient of friction. Examples of abrasives include one or more abrasives selected from the group consisting of alumina, quartz, silicon carbide, cubic boron nitride, and diamond. When the particles 30 are abrasives, they are expected to increase the coefficient of friction and function as an abrasive. Examples of biocompatible materials include hydroxyapatite, steroids, hyaluronic acid, and one or more materials selected from the group consisting of biocompatible metals, biocompatible resins, and biocompatible ceramics. When the particles 30 are a biocompatible material, the affinity between the biocompatible member and biological tissue can be improved on the sliding surface 10A of the biocompatible member. Such a configuration is suitable for the sliding surfaces of sliding members such as bone screws and artificial joints. That is, by appropriately selecting and using the particles 30, desired properties can be imparted to the sliding surface 10A.

[0044] The particle size of the particles 30 is at least half the thickness of the laminated portion 222 and is preferably 100 μm or less, and more preferably 0.1 μm or more and 100 μm or less. If the particle size of the particles 30 is above the lower limit, it is easy to achieve a structure in which part of the particles 30 is exposed from the laminated portion 222. If the particle size of the particles 30 is below the upper limit, the solid lubricant protrudes due to deformation and wear of the resin layer caused by contact, thereby achieving a friction-reducing effect. The particle size can be calculated by obtaining a particle image by microscopic observation and calculating the diameter of a circle equivalent to the area of ​​the particle image.

[0045] In the particle disposing step, the particles 30 are disposed on the surface of the substrate 11. In the particle disposing step, for example, the powder particles 30 may be sprinkled onto the substrate 11, or the particles 30 may be suspended in a solvent such as an organic solvent and sprayed onto the substrate 11, and the solvent may then be removed. The particles 30 disposed on the surface of the substrate 11 have gaps between them. That is, in the particle disposing step, the particles 30 are deposited on the surface of the substrate 11 in a porous state. The height of the deposited particles 30 is not particularly limited, but can be equal to or greater than the particle diameter of the particles 30 and equal to or less than three times the particle diameter of the particles 30. Before the spraying step, the particles 30 are disposed on the surface of the substrate 11 in a state of contact with but not adhering to the substrate 11.

[0046] In the step of forming the laminated portion 222, the material 23 of the laminated portion 222 is sprayed from above the particles 30 to form the laminated portion 222 in which the particles 30 are embedded. "Above the particles 30" means the side opposite the substrate 11 with respect to the particles 30, and may be diagonally above the particles 30 with respect to the substrate 11. The step of forming the laminated portion 222 can be performed in the same manner as the spraying step and curing step in the first embodiment.

[0047] In the spraying step, droplets of the material 23 for the laminated portion 222 are applied to particles 30 located at the formation site of the laminated portion 222, among the particles 30 arranged on the surface of the substrate 11. The droplets of the material 23 for the laminated portion 222 that have landed on the particles 30 spread while penetrating into the gaps between the particles 30. A curing step is performed in this state to form the laminated portion 222 in which the particles 30 are embedded. The laminated portion 222 also serves as an adhesive that bonds the particles 30 to the surface of the substrate 11. The particles 30 embedded in the laminated portion 222 may be partially exposed on the surface of the laminated portion 222, or may appear on the surface of the laminated portion 222 as the laminated portion 222 wears during use of the sliding member 210.

[0048] The cleaning step is a step of removing particles 30 located outside the formation portion of the laminated portion 222 from among the particles 30 arranged on the surface of the substrate 11. Even if the cleaning step is not performed, the cleaning step does not have to be performed if the recesses 21 around the laminated portion 222 function as oil reservoirs.

[0049] According to this embodiment, it is possible to form the laminated portion 222 in which the particles 30 are embedded, and it is possible to impart desired properties to the sliding surface 10A depending on the properties of the particles 30. For example, when the particles 30 are a solid lubricant, this can contribute to reducing the coefficient of friction.

[0050] <Embodiment 4> The surface treatment method for a sliding member 210 according to the fourth embodiment differs from that of the third embodiment in that a liquid having a friction reducing function is used instead of the particles 30 as a solid lubricant.

[0051] Examples of the liquid having a friction-reducing function include friction modifiers such as zinc dialkyldithiophosphate (ZnDTP) and molybdenum dialkyldithiophosphate (MoDTC). The liquid having a friction-reducing function may be sprayed onto the surface of the substrate 11 in advance and disposed as droplets on the surface of the substrate 11. Alternatively, the liquid may be mixed into the material 23 of the laminate portion 222 and sprayed onto the surface of the substrate 11 together with the material 23 of the laminate portion 222.

[0052] According to this embodiment, it is possible to form the laminated portion 222 containing a liquid having a friction reducing function, which can contribute to reducing the coefficient of friction of the sliding surface 10A.

[0053] <Embodiment 5> The slide member 910 according to the fifth embodiment includes a base layer 940 that serves as a base for the laminated portion 922. The surface processing method for the slide member 910 includes a step of forming the base layer 940 by spraying a material 941 of the base layer 940 in a solid pattern onto the surface of the substrate 11 before the step of forming the laminated portion 922. Detailed description of the same components as those in the above embodiments will be omitted. The following description will be given with reference to FIG. 11.

[0054] The step of forming the base layer 940 can be performed using the same material and method as the step of forming the first layer 22A described in embodiment 2, except for the pattern in which the material 941 of the base layer 940 is sprayed. For example, the base layer 940 can be formed using the white ink described in embodiment 2. By forming the base layer 940 from a resin, the adhesive strength of the laminated portion 922 to the base layer 940 can be increased.

[0055] The step of forming the laminated portion 922 can be performed using the same materials and the same method as in the step of forming the second layer 22B described in embodiment 2. For example, the laminated portion 922 can be formed using the black ink described in embodiment 2.

[0056] According to this embodiment, the shape of the laminated portion 922 can be maintained, and desired sliding characteristics can be maintained for a long period of time. Specifically, since the laminated portion 922 is formed by the pattern of the texture 20, it is presumed that stress concentrates on the outline of the pattern when the sliding member 910 slides, causing peeling or the like. Since the base layer 940 is formed by a solid pattern, the outline of the pattern is small, making peeling or the like less likely to occur. Furthermore, the adhesive strength of the laminated portion 922 to the resin base layer 940 is stronger than the adhesive strength to the metal substrate 11. Therefore, according to a configuration including the base layer 940, the laminated portion 922 is less likely to peel off and the shape of the laminated portion 922 can be suitably maintained compared to a configuration not including the base layer 940.

[0057] 13B, the boundary between the laminated portion 922 and the base layer 940 may have a gradient composition in which the components of both are mixed. Such a gradient composition can be suitably achieved, for example, by milding the conditions for irradiating ultraviolet light in the curing step when forming the base layer 940. That is, by reducing the output power and irradiation time of the ultraviolet light, the uncured material 941 of the base layer 940 remains, and the material 941 of the base layer 940 and the material 23 of the laminated portion 922 are partially mixed together, thereby forming a gradient composition.

[0058] <Embodiment 6> The slide member 1010 according to the sixth embodiment includes a connecting layer 1040 that fills in the gaps between the patterns of the laminated portion 1022 and is continuous with the laminated portion 1022. The surface processing method for the slide member 1010 includes, prior to the step of forming the laminated portion 1022, a step of spraying a material 1041 for the connecting layer 1040 onto the surface of the substrate 11 in a solid pattern that at least fills in the gaps between the patterns of the laminated portion 1022 to form the connecting layer 1040. Detailed description of the same components as those in the above embodiments will be omitted. The following description will be given with reference to FIG. 12.

[0059] The step of forming the connecting layer 1040 can be performed using the same material and method as the step of forming the first layer 22A described in embodiment 2, except for the pattern in which the material 1041 of the connecting layer 1040 is sprayed. For example, the connecting layer 1040 can be formed using the white ink described in embodiment 2. By forming the connecting layer 1040 from a resin, the adhesive strength of the laminated portion 1022 to the connecting layer 1040 can be increased.

[0060] The step of forming the laminated portion 1022 can be performed using the same materials and the same method as the step of forming the second layer 22B described in embodiment 2. For example, the laminated portion 1022 is formed using the black ink described in embodiment 2. The height of the laminated portion 1022 is preferably equal to or greater than the height of the connecting layer 1040, and more preferably equal to the height of the connecting layer 1040.

[0061] According to this embodiment, the shape of the laminated portion 1022 can be maintained, and the desired sliding characteristics can be maintained for a long period of time. In particular, the connecting layer 1040 can reduce deformation of the laminated portion 1022 and the force applied to the contour portion of the pattern of the laminated portion 1022. Therefore, a configuration including the connecting layer 1040 can more preferably maintain the shape of the laminated portion 1022 than a configuration not including the connecting layer 1040.

[0062] Furthermore, according to this embodiment, even if the stacked portion 1022 and the connecting layer 1040 are connected in a flat manner, by making the stacked portion 1022 and the connecting layer 1040 have different compositions, it is possible to intentionally arrange surface structures with different characteristics within the flat surface.

[0063] In order to improve the adhesive strength between the laminated portion 1022 and the connecting layer 1040, the laminated portion 1022 and the connecting layer 1040 may have a gradient composition in which their components are mixed together, as shown in (C) of Fig. 13. The method for forming the gradient composition can be the same as that for the gradient composition of the laminated portion 922 and the base layer 940, and therefore a description thereof will be omitted.

[0064] <Embodiment 7> 13(A), in the slide member 1110 according to the seventh embodiment, the connecting layer 1140 and the laminated portion 1122 are formed so that the connecting layer 1140 and the laminated portion 1122 partially overlap each other. The height of the laminated portion 1122 may be equal to or greater than the height of the connecting layer 1140. In this manner, by adjusting the conditions for forming the connecting layer 1140 and the laminated portion 1122, it is possible to simultaneously realize an arrangement of surface textures with different properties resulting from differences in the compositions of the laminated portion 1122 and the connecting layer 1140, and the formation of a texture 20 having an uneven shape.

[0065] In order to improve the adhesive strength between the laminated portion 1122 and the connecting layer 1140, the laminated portion 1122 and the connecting layer 1140 may have a gradient composition in which their components are mixed together, as shown in (D) of Fig. 13. The method for forming the gradient composition can be the same as that for the gradient composition of the laminated portion 922 and the base layer 940, and therefore a description thereof will be omitted.

[0066] <Embodiment 8> The substrate 1211 according to the eighth embodiment is a metal substrate, and has a plurality of holes 1212 scattered on the surface. The surface processing method of the sliding member 1210 differs from that of the fifth embodiment in that it includes a step of forming the plurality of holes 1212 by electrolytic polishing before the step of forming the laminated portion 1222. Detailed description of the same components as those of the fifth embodiment will be omitted. The following description will be given with reference to FIG. 14.

[0067] The process of forming the multiple holes 1212 involves electrolytic polishing under specified conditions, which locally dissolves the surface of the substrate 1211 and forms the multiple holes 1212. Electrolytic polishing is a surface treatment method that utilizes the dissolution of a metal anode through electrolysis. In the process of forming the multiple holes 1212, an anode is connected to the substrate 1211 made of the metal material of the sliding member 1210, a cathode is connected to the counter electrode, and an electric current is passed through the substrate 1211 in an electrolytic solution, causing anodic melting. Electrolytic polishing is an electrochemical process that does not generate residual stress, and is also characterized by its ability to process components that are difficult to form multiple holes 1212 in using conventional processing methods, such as cylindrical, complex, and small components.

[0068] As shown in the upper row of the "D: Electro polishing-White (all)-Black (Φ1 mm)" column in Figure 18, multiple holes appear as black dots on the surface of the substrate (disk) of Example 4. Each of the multiple holes 1212 is a minute depression, for example, with a maximum opening diameter of 100 μm or less. The multiple holes 1212 are also called corrosion pits or corrosion holes. The multiple holes 1212 are provided in a continuous area in the pattern of the laminated portion 1222, for example, overlapping with one dot of the laminated portion 1222.

[0069] The electrolyte 1240 used in electropolishing is an aqueous solution containing one or more selected from the group consisting of sodium chloride, ferric chloride, lithium chloride, magnesium chloride, calcium chloride, potassium chloride, sodium bicarbonate, citric acid, acetic acid, disodium succinate, and other food additives. Among these, an aqueous solution of sodium chloride is particularly preferred, considering the safety of handling, ease of availability, and disposal of the electrolyte 1240 after use. Other conditions, equipment, etc. used in electropolishing can be appropriately selected from conventionally known electropolishing conditions, equipment, etc. More specific details will be described in the Examples below.

[0070] According to this embodiment, an anchor effect can be achieved by the material 941 of the base layer 940 penetrating into and solidifying in the plurality of holes 1212. Therefore, by increasing the adhesive strength of the base layer 940 and the laminated portion 1222 to the base material 1211, the shape of the laminated portion 1222 can be maintained, and the desired sliding characteristics can be maintained for a long period of time.

[0071] <Embodiment 9> The surface processing method for the slide member 10 according to the ninth embodiment differs from that of the first embodiment in that it includes a step of electrolytically polishing the portion of the surface of the base material 11 that is not covered with the laminated portion 22. Detailed description of the same components as those of the first embodiment will be omitted.

[0072] The electrolytic polishing step is a step of forming the recesses 21 of the texture 20 by electrolytic polishing. The electrolytic solution used for the electrolytic polishing can be the same as the electrolytic solution of embodiment 9. As for other conditions, devices, etc. for the electrolytic polishing, conventionally known conditions, devices, etc. for electrolytic polishing can be appropriately adopted.

[0073] According to this embodiment, electrolytic polishing can be used to make the portions of the surface of the base material 11 that are not covered with the laminated portion 22 recessed relative to the portions that were covered with the laminated portion 22. Therefore, even if the laminated portion 22 is worn, an oil reservoir can be secured by the uneven shape of the surface of the base material 11.

[0074] <Embodiment 10> The surface processing method for the slide member 10 according to the tenth embodiment differs from that of the first embodiment in that it includes a step of plating the portion of the surface of the base material 11 that is not covered with the laminated portion 22. Detailed description of the same components as those of the first embodiment will be omitted.

[0075] The plating step is a step of forming a metal film on the inner surface of the recesses 21 of the texture 20 by electroplating and dry plating. Electroplating is a surface treatment method that forms a metal thin film by cathodic reduction of metal ions in an aqueous solution using an external DC power source. Examples of metal thin films include zinc films, tin films, and mixed zinc-tin films. Other conditions, devices, etc. for electroplating can be appropriately selected from those used in conventionally known plating processes.

[0076] According to this embodiment, a metal coating can be formed on the surface of the substrate 11 in areas that are not covered with the laminated portion 22. This allows a texture to be formed with the metal coating, and a surface shape that can withstand a higher load than a configuration that has only the laminated portion 22 of the resin coating can be obtained.

[0077] <Embodiment 11> The surface processing method for the slide member 10 according to the eleventh embodiment differs from that of the first embodiment in that it includes a step of projecting particles onto the surface of the substrate 11 after the laminated portion 22 has been formed, thereby modifying the portions not covered by the laminated portion 22. Detailed description of the same components as those in the first embodiment will be omitted.

[0078] The process of modifying the areas not covered by the laminated portion 22 is a process of modifying the areas not covered by the laminated portion 22 by shot peening. The mode of modification by shot peening is not particularly limited as long as the properties of the projected area change before and after particle projection. Examples of the mode of modification by shot peening include a mode in which the area not covered by the laminated portion 22 is plastically deformed to increase the surface hardness, a mode in which a fine uneven shape is imparted to the area not covered by the laminated portion 22, a mode in which a functional component such as a solid lubricant is compounded with the projected particles to impart the functional component such as a solid lubricant to the area not covered by the laminated portion 22, and a combination of these modes. The particles used in shot peening, other conditions, equipment, etc., can be appropriately selected from conventionally known shot peening particles, conditions, equipment, etc.

[0079] According to this embodiment, by modifying the portion not covered by the laminated portion 22, it is possible to make the portion on the surface of the base material 11 covered by the laminated portion 22 have different properties from the portion not covered by the laminated portion 22. Therefore, even if the laminated portion 22 is worn, it is possible to intentionally arrange surface textures with different properties within the surface of the base material 11.

[0080] <Other embodiments> The present disclosure is not limited to the embodiments, and the following embodiments, for example, are also included in the technical scope.

[0081] (1) The step of forming the laminated portion may be performed by a transfer printing method in which the material for the laminated portion is sprayed onto the surface of a transfer sheet in a textured pattern and then transferred from the transfer sheet to the surface of the substrate. In this way, the laminated portion can be suitably formed even when the sliding surface is a curved surface of the sliding member or when printing with a general-purpose printer is difficult due to the thickness of the substrate. The material for the laminated portion is not limited to black ink or white ink, and inks of other colors may also be used. The material for the laminated portion may be ink for general-purpose inkjet printers or a material specifically for sliding members (for example, an ultraviolet-curable resin material blended with a lubricant, oil, etc.). (2) When the laminated portion has a multi-layer structure, the laminated portion may have three or more layers. As in laminated portion 322 shown in FIG. 8A, the diameter of the second layer 22B may be smaller than that of the first layer 22A. Also, as in laminated portion 422 shown in FIG. 8B, the diameter of the second layer 22B may be larger than that of the first layer 22A. Alternatively, the first layer and the second layer may be laminated with their centers offset. In this way, by adjusting the degree of overlap of the layers in the laminated portion, the shape of the laminated portion can be appropriately designed, and the texture can be optimized. (3) As shown in Fig. 9, texture 520 may have a plurality of recesses 521 and stacked portions 522 located between the recesses 521. The stacked portions 522 have a continuous shape. The texture is a so-called concave texture. (4) The sliding surface may be a surface of the sliding member that is based on a curved surface. An example of such a sliding surface is the outer peripheral surface of a cylindrical member. When the sliding surface of the sliding member is based on a curved surface, it is preferable that the sliding surface of the mating member is also based on a curved surface that extends parallel to the sliding surface of the sliding member. (5) The shape, size, and pitch of the laminated portions can be changed as appropriate. As in the texture 620 shown in FIG. 10A, the laminated portions 622 may be tapered toward the sliding direction of the mating member relative to the sliding member. Furthermore, in an actual sliding surface, the oil flow direction may be controlled by, for example, arranging elliptical convex portions at an angle in a plan view, taking into account the flow path from the oil supply portion. This configuration can suppress oil film breakdown and stabilize friction. As in the texture 720 shown in FIG. 10B, multiple laminated portions 722 may include portions of different sizes in a plan view. As in the texture 820 shown in FIG. 10C, multiple laminated portions 822 may be arranged at different pitches in a plan view. (6) The plurality of laminated portions may be arranged in a square lattice pattern or a face-centered tetragonal lattice pattern other than a hexagonal lattice pattern. Similarly, in the case of a concave texture, the plurality of recesses may be arranged in a hexagonal lattice pattern, a square lattice pattern, or a face-centered tetragonal lattice pattern. (7) The frictional characteristics improved by the texture are not limited to a reduction in the friction coefficient. The surface processing method for a slide member according to the present embodiment has a high degree of freedom in the shape of the texture, and is therefore effective for improving frictional characteristics other than a reduction in the friction coefficient. The frictional characteristics improved by the texture may be, depending on the performance required of the slide member, a reduction in the fluctuation range of the friction coefficient, maintaining a predetermined friction coefficient for a long period of time, an increase in the friction coefficient, or the like.

[0082] (8) The substrate may be made of resin. When the substrate is made of resin, it is easier to ensure adhesion to the resin laminated portion compared to a metal substrate. Therefore, even if, for example, an underlayer or multiple holes are not provided, peeling of the laminated portion can be suppressed and the shape of the laminated portion can be favorably maintained.

[0083] (9) The above embodiments can be combined as appropriate. For example, the laminated portion described in embodiment 1 may be formed on the substrate having a plurality of holes described in embodiment 8. [Example]

[0084] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these. In Figures 15 to 23, the correspondence between each example and the alphabetic symbols is as follows: Example 1: A, Example 2: B, Example 3: C, Example 4: D, Example 5: E, and Example 6: F.

[0085] <Examples 1 and 2> 1. Preparation of the test specimen (disc) A carbon steel (S45C) disk was prepared having an inner diameter of 20 mm, an outer diameter of 44 mm, and a thickness of 7 mm. The disk of Example 1 was not subjected to electrolytic polishing treatment. The disk of Example 2 was subjected to electrolytic polishing using an electrolytic polishing device. 1% saline solution was used as the electrolyte. The disk was fixed using a jig, and one end of the disk was completely immersed in the electrolyte. An anode was connected to the disk side, and a cathode was connected to a stainless steel dish submerged in the electrolyte. A current was applied from a function generator, and electrolytic polishing was performed. The electrolytic polishing conditions were: temperature: room temperature, time: 30 seconds, voltage: 1.40 V, current: 0.102 A.

[0086] Next, a laminated portion was formed on the discs of Example 1 and Example 2 using an inkjet printer (manufactured by Birdland Machine LLC, model number: FSA3UV) and black ink (manufactured by Zhuhai huacai New Materials Technology Co., Ltd, model number: Industrial Printers serials UV INK FOR EPSON-BLACK). The texture pattern was dot-shaped. The diameter of the formed laminated portion was approximately 1000 μm. Example 1 is an example of the above-mentioned embodiment 1.

[0087] Optical microscope images of the obtained disks of Example 1 and Example 2 are shown in Figure 15. The lower row of the "A: Black (Φ1 mm)" column in Figure 15 shows the state of the laminated portion of Example 1. The upper row of the "B: Electro polishing-Black (Φ1 mm)" column in Figure 15 shows the state of the disk after electropolishing but before the formation of the laminated portion. It can be seen that multiple holes formed by electropolishing are scattered on the surface of the disk. The lower row of the "B: Electro polishing-Black (Φ1 mm)" column in Figure 15 shows the state of the laminated portion of Example 2.

[0088] 2. Friction test method (1) Counterpart The mating material was a carbon steel ring (S45C, contact width 2 mm) that was quenched to a hardness of 600 Hv.

[0089] (2) Test conditions A ring-on-disc test was carried out under the following conditions: Test load: 300N Contact surface pressure: 1.6MPa Test speed: 1.0 m / s Test distance: 2000m Lubricating oil: mineral oil (SIP-E). The amount of lubricating oil was 200 μL.

[0090] 3.Results (1) Change in friction coefficient over time The change in the friction coefficient over time for Examples 1 and 2 is shown in Figure 16. The horizontal axis represents the sliding distance (m), and the vertical axis represents the friction coefficient. As shown in the graph in Figure 16, Example 1:A and Example 2:B had small friction coefficients at sliding distances of approximately 3 m to 23 m, confirming their excellent friction characteristics. Example 2:B had an even smaller friction coefficient up to a sliding distance of approximately 50 m, confirming its superior friction characteristics over a longer period than Example 1:A. It is presumed that the formation of multiple holes in Example 2 allowed the shape of the laminate to be maintained for a longer period than Example 1.

[0091] These results suggest that a sliding member with good friction characteristics can be obtained by a simple method of forming a laminate by spraying the laminate material in a textured pattern. Furthermore, it is suggested that a sliding member with even better friction characteristics can be obtained by forming multiple holes by electropolishing.

[0092] (2) Optical microscope image and cross-sectional curve of the sliding surface after the test The sliding surfaces of the test piece (disk) and the mating member (ring) after the test and their cross-sectional curves are shown in Figure 17. In both Example 1:A and Example 2:B, the shape of the laminated portion was distorted on the sliding surfaces of the test pieces after the test, and the ink spread. In addition, in both Example 1:A and Example 2:B, the ink in the laminated portion was transferred to the sliding surface of the mating member.

[0093] <Examples 3 and 4> 1. Preparation of the test specimen (disc) The disks of Examples 3 and 4 were subjected to the same electrolytic polishing treatment as in Example 2, except that the conditions for electrolytic polishing were: temperature: room temperature, time: 30 seconds, voltage: 2.50V, and current: 0.250A.

[0094] Next, for the disk of Example 3, a laminated portion was formed in the same manner as in Example 2, except that the texture pattern was oval in shape. The texture pattern was set so that the major axis of the oval was 1 mm, the minor axis was 0.5 mm, and the major axis direction was approximately aligned with the sliding direction. For the disk of Example 4, before the step of forming the laminated portion, the material for the primer layer was sprayed onto the surface of the substrate in a solid pattern to form the primer layer. The primer layer was formed using the same inkjet printer and white ink (manufactured by Zhuhai huacai New Materials Technology Co., Ltd., model number: Industrial Printers serials UV INK FOR EPSON-WHITE) as in Example 2. The laminated portion was otherwise formed in the same manner as in Example 2. Example 4 is an example of the above-mentioned embodiment 8.

[0095] Optical microscope images of the obtained disks of Examples 3 and 4 are shown in Figure 18. The column "C: Electro polishing - Black (ellipse)" in Figure 18 shows the state of the disk before forming the laminated portion of Example 3, and the state of the laminated portion. The column "D: Electro polishing - White (all) - Black (Φ1 mm)" in Figure 18 shows the state of the disk before forming the laminated portion of Example 4, and the state of the laminated portion.

[0096] 2. Friction test method A friction test was carried out under the same conditions as in Examples 1 and 2.

[0097] 3.Results (1) Change in friction coefficient over time The change in the friction coefficient over time for Examples 2, 3, and 4 is shown in Figure 19. The horizontal axis represents the sliding distance (m), and the vertical axis represents the friction coefficient. As shown in the graph in Figure 19, Example 3:D and Example 4:E maintained a small friction coefficient up to the end of the test (sliding distance 2000 m), confirming their excellent friction characteristics.

[0098] These results suggest that a slide member with good friction characteristics can be obtained by a simple method by spraying the laminate material in a textured pattern to form the laminate. Furthermore, it was suggested that a slide member with even better friction characteristics can be obtained by appropriately designing the shape of the laminate. It was also suggested that a slide member with even better friction characteristics can be obtained by forming a base layer.

[0099] (2) Optical microscope image and cross-sectional curve of the sliding surface after the test The sliding surfaces of the test piece (disk) and the mating member (ring) after the test and their cross-sectional curves are shown in Figure 20. In both Example 3:C and Example 4:D, the shape of the laminated portion was distorted on the sliding surfaces of the test pieces after the test, and the ink spread. In addition, in both Example 3:C and Example 4:D, the ink in the laminated portion was transferred to the sliding surface of the mating member.

[0100] <Examples 5 and 6> 1. Preparation of the test specimen (disc) The disks of Examples 5 and 6 were subjected to the same electrolytic polishing treatment as in Examples 3 and 4. Next, for the disc of Example 5, cyan ink (manufactured by Zhuhai huacai New Materials Technology Co., Ltd., model number: Industrial Printers serials UV INK FOR EPSON-CYAN) was used as the ink for the laminated portion. Otherwise, a test piece was prepared in the same manner as in Example 4. For the disk of Example 6, a test specimen was prepared in the same manner as in Example 4, except that the texture pattern was oval. The texture pattern was set so that the major axis of the oval was 1 mm, the minor axis was 0.5 mm, and the major axis direction was approximately aligned with the sliding direction.

[0101] Optical microscope images of the obtained disks of Examples 5 and 6 are shown in Fig. 21. The column "E: Electro polishing - White (all) - Cyan (Φ1 mm)" in Fig. 21 shows the state of the laminated portion of Example 5. The column "F: Electro polishing - White (all) - Black (ellipse 1 x 0.5 mm)" in Fig. 21 shows the state of the laminated portion of Example 6.

[0102] 2. Friction test method A friction test was carried out under the same conditions as in Examples 1 and 2.

[0103] 3.Results (1) Change in friction coefficient over time The change in the friction coefficient over time for Examples 3 to 6 is shown in Figure 22. The horizontal axis represents the sliding distance (m), and the vertical axis represents the friction coefficient. As shown in the graph in Figure 22, Example 5:E and Example 6:F had small friction coefficients up to the end of the test (sliding distance 2000 m), confirming their excellent friction characteristics.

[0104] These results suggest that a sliding component with good friction characteristics can be obtained by a simple method of spraying the laminate material in a textured pattern to form the laminate. Furthermore, it was suggested that the friction coefficient can be adjusted by appropriately designing the resin material. It was also suggested that a sliding component with even better friction characteristics can be obtained by appropriately designing the shape of the laminate and forming a base layer.

[0105] (2) Optical microscope image and cross-sectional curve of the sliding surface after the test The sliding surfaces of the test piece (Disk) and the mating member (Ring) after the test, as well as their cross-sectional curves, are shown in Figure 23. In Example 5:E, the shape of the laminated portion was distorted on the sliding surface of the test piece after the test, and the ink had spread. In addition, in Example 5:E, the ink in the laminated portion had transferred to the sliding surface of the mating member. In Example 6:F, the shape of the laminated portion was maintained on the sliding surface of the test piece after the test. In addition, in Example 6:F, the amount of ink transferred from the laminated portion to the sliding surface of the mating member was small.

[0106] According to this example, a surface processing method for a slide member that can obtain a slide member having good friction characteristics by a simple method, and such a slide member can be provided.

[0107] The present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the claims of the present disclosure. [Explanation of symbols]

[0108] 10, 110, 210, 910, 1010, 1110, 1210... Sliding member, 10A... Sliding surface, 11, 1211... Substrate, 20, 520, 620, 720, 820... Texture, 21, 521... Recess, 22, 122, 222, 322, 422, 522, 622, 722, 822, 922, 1022, 1122, 1222... Laminated portion, 22A... First layer, 22B... Second layer, 23... Laminated portion material, 30... Particle, 50... Counterpart material, 50A... Sliding surface, 940... Base layer, 941... Base layer material, 1040, 1140... Connecting layer, 1041... Connecting layer material, 1212... Hole, 1240... Electrolyte

Claims

1. A surface processing method for a slide member having a texture formed by a laminated portion laminated on a surface of a base material, comprising: the texture is configured to include a plurality of the laminated portions forming floating islands and a recessed portion provided surrounding the laminated portions, the laminated portion is configured as a resin layer containing one or more substances selected from the group consisting of carbon black, particles of a solid lubricant, particles of an abrasive, particles of a biocompatible material, and a liquid having a friction-reducing function; A surface processing method for a sliding member, comprising a step of spraying a material for the laminated portion in the pattern of the texture to form the laminated portion while fixing the substance on the surface of the base material.

2. a step of disposing one or more types of particles selected from the group consisting of particles of the solid lubricant, particles of the abrasive, and particles of the biocompatible material on the surface of the substrate before the step of forming the laminated portion; 2. The surface processing method for a slide member according to claim 1, wherein the step of forming the laminated portion comprises spraying a material for the laminated portion onto the arranged particles to form the laminated portion in which the particles are embedded.

3. A surface processing method for a sliding member as described in claim 2, wherein the particle size of one or more types of particles selected from the group consisting of particles of the solid lubricant, particles of the abrasive, and particles of the biocompatible material is at least half the thickness dimension of the laminated portion and is 100 μm or less.

4. The step of forming the laminated portion includes: jetting the laminate material in the pattern of the texture to form a first layer of the laminate; The surface processing method for a slide member according to any one of claims 1 to 3, wherein a material for the laminated portion is jetted onto the first layer to form a second layer of the laminated portion.

5. the sliding member includes a base layer that serves as a base for the laminated portion, 5. The surface processing method for a slide member according to claim 1, further comprising, before the step of forming the laminated portion, a step of spraying a material of the base layer onto a surface of the base material in a fill pattern to form the base layer.

6. the substrate is a metal substrate and has a plurality of holes scattered on a surface thereof; 6. The surface processing method for a slide member according to claim 1, further comprising the step of forming the plurality of holes by electrolytic polishing before the step of forming the laminated portion.

7. the substrate is a metal substrate, the sliding member has the base material exposed at a portion not covered by the laminated portion, 7. The method for processing the surface of a slide member according to claim 1, further comprising the step of electrolytically polishing a portion of the surface of the base material that is not covered with the laminated portion.

8. the substrate is a metal substrate, the sliding member has the base material exposed at a portion not covered by the laminated portion, 8. The method for processing the surface of a slide member according to claim 1, further comprising the step of plating a portion of the surface of the base material that is not covered with the laminated portion.

9. the substrate is a metal substrate, the sliding member has the base material exposed at a portion not covered by the laminated portion, 9. The surface processing method for a slide member according to claim 1, further comprising a step of projecting particles onto a surface of the base material in a state where the laminated portion is formed, thereby modifying a portion not covered with the laminated portion.

Images