JP7339154B2 - SLIDING MEMBER AND METHOD FOR MANUFACTURING SLIDING MEMBER - Google Patents

Description

The present invention relates to a sliding member and a method for manufacturing the sliding member.

As a type of drainage pump, a preceding standby operation pump is known. Preceding standby operation pumps can be operated at full speed (preceding standby operation) in an anhydrous state in advance in order to respond to a sudden increase in water volume, such as a sudden torrential rain, or can drain water in a mixed state of air and water. It's becoming A sliding member that can be applied to such a pre-standby operation pump and a method for manufacturing the same are disclosed in, for example, Patent Document 1.

Patent Literature 1 discloses a pump shaft/bearing structure including a sliding member base and sliding particles. It is described that the sliding particles are scattered and fixed on the surface of the base of the sliding member, protrude from the surface of the base of the sliding member, and come into sliding contact with the member to be slid. Further, in Patent Document 1, a sliding member is manufactured by directly fixing sliding contact particles having an average particle diameter of 10 to 500 μm to the surface of the base of the sliding member by electrodeposition or spark plasma sintering. is described.

Japanese Patent Application Laid-Open No. 2016-211727 (published on December 15, 2016)

FIG. 10 is a schematic diagram showing how hard particles are fixed to a substrate by a conventional method, and FIG. 10(a) is a schematic diagram showing how hard particles are fixed to a substrate by electrodeposition. 10(b) is a schematic diagram showing how the hard particles are fixed to the substrate by spark plasma sintering. As will be described later, in the figure, 10a represents a substrate, 10b represents hard particles, and 10c represents a plated layer.

As shown in FIG. 10(a), in the electrodeposition, hard particles 10b, which are the raw material of the sliding contact particles, are fixed on the surface of the substrate 10a to form the plated layer 10c. The lower end or lower surface of the particle 10b is placed. Spark plasma sintering is a method of pressurizing the powder of hard particles 10b and pressing it into the substrate 10a.

On the other hand, the hard particles 10b are aggregates of many particles and have a particle size distribution. Therefore, when the hard particles 10b are fixed to the substrate 10a by the method disclosed in Patent Document 1, as shown in FIGS.

However, the tip of the hard particle 10b facing the member to be slid has a step. For example, in FIG. 10, the height from the dotted line to the tip of the hard particle 10b shown above the dotted line differs for each particle.

The tip portion of the hard particle 10b has a surface that forms a sliding contact surface that makes sliding contact with an opposing member to be slid (hereinafter, "a surface that forms a sliding contact surface that makes sliding contact with the member to be slid" is referred to as a "surface A"). may be).

The processing is performed by processing the tip portions of the hard particles 10b having different heights from the surface of the substrate 10a so that the tip portions are aligned on the same circumference. When the tips of the hard particles 10b are aligned on the same circumference, a sliding contact surface 12, which is a circumferential surface around the axis of the shaft member 10, is formed as shown in FIG. 1, which will be described later. The hard particles having the face A are called sliding particles.

As shown in FIGS. 10(a) and 10(b), after fixing the hard particles 10b so that the lower ends or the lower surfaces of the hard particles 10b are aligned without steps, the above processing is performed to obtain the surface A. , the particle size of the hard particles 10b is required to be within a predetermined range.

This is because when hard particles 10b with a wide range of particle diameters are used, the height from the surface of the substrate 10a to the tip of the hard particles 10b varies greatly among the plurality of hard particles 10b. .

If the height differs greatly depending on the particles, a processing step (grinding and/or polishing the hard particles 10b) for forming the surface A so that the height from the surface of the substrate 10a to the surface A is uniform becomes essential. . At the same time, in order to provide the surface A on the small hard particles 10b and make the heights uniform, the grinding amount of the large hard particles 10b inevitably increases. Therefore, it is inefficient both in terms of processing and materials.

In particular, when the amount of grinding and/or polishing increases in the above-described processing steps, the fixed layer (plated layer 10c) is also ground. There is a possibility that the peeling resistance may deteriorate.

When using hard particles with a wide particle size range and using hard particles with a narrow particle size range, the former is more advantageous in terms of raw material cost. However, there is the aforementioned problem of poor efficiency in terms of both processing and materials.

Further, even when hard particles having a narrow particle size range are used, if the lower end portion or the lower surface is fixed to the substrate 10a without a step, some step will occur. Therefore, there was much expectation that the amount of processing could be reduced if the tips of the hard particles could be aligned and fixed to the substrate 10a.

Furthermore, in Patent Document 1, hard particles with an average particle diameter of 10 to 500 μm are used as sliding contact particles, but when the sliding contact particles are fixed by plating, a particle diameter of around 100 μm poses a problem. However, the closer the particle diameter is to 500 μm, the longer it takes to obtain a stable plating layer, which is industrially disadvantageous. Therefore, there have been many expectations for a method of reducing the portion where plating contributes to fixation of hard particles.

The present invention has been made in view of the above problems, and an object of the present invention is to easily form a sliding contact surface by suppressing the amount of processing without being influenced by the range of particle diameters of hard particles. An object of the present invention is to provide a method for manufacturing a moving member and a sliding member.

In order to solve the above problems, a sliding member according to an embodiment of the present invention and a method for manufacturing the sliding member according to an embodiment of the present invention include the following inventions.

[1] A sliding member that slides relative to a member to be slid,
a sliding member base;
A surface where tips of hard particles, which are scattered and fixed on the surface of the sliding member base and have an average particle diameter of more than 50 μm and 500 μm or less, form a sliding contact surface that makes sliding contact with the member to be slid. a sliding particle having
The surface of the base of the sliding member has a concave portion formed so that a portion of the sliding contact particles can be embedded therein, and a convex portion formed around the concave portion so as to surround the concave portion,
The sliding particles have a portion embedded in the recess and a portion protruding from the recess, and the protruding portion is formed around the portion protruding from the recess. Element.

[2] The surface of the base of the sliding member has a horizontal portion that forms a substantially horizontal surface, and is a portion other than the concave portion and the convex portion. The sliding member according to [1], wherein the height is higher than the height from the horizontal portion to the tip of the convex portion.

[3] The sliding according to [1] or [2], wherein the tip of the convex portion is separated from the sliding particle, and a space is provided between the tip of the convex portion and the sliding particle. moving parts.

[4] The sliding member according to [1] or [2], wherein the tip of the projection has a substantially horizontal surface.

[5] The sliding member according to any one of [1] to [4], wherein the sliding member base includes a substrate and a surface forming portion formed on the surface of the substrate.

[6] The sliding member according to [5], wherein the substrate has a hardness of Hv200 kg/mm ² or less, and the surface forming portion has a hardness of Hv400 kg/mm ² or more.

[7] The sliding member according to any one of [1] to [6], wherein the hard particles have a hardness equal to or higher than that of silica sand and a compressive strength of 200 kg/mm ² or higher.

[8] Any of [1] to [7], wherein the hard particles are one or more selected from the group consisting of diamond, cubic boron nitride, silicon nitride, alumina, and a composite material of WC and WC. 1. The sliding member according to claim 1.

[9] A method for manufacturing a sliding member that slides relative to a member to be slid,
a first step of fixing hard particles having an average particle size of more than 50 μm and not more than 500 μm so as to be dispersed on the surface of the base of the sliding member;
a second step of press-fitting the hard particles into the sliding member base in an environment of 500° C. or less so that the height from the surface of the sliding member base to the tip of the hard particles is substantially constant; ,
A method of manufacturing a sliding member, comprising a third step of processing the hard particles press-fitted in the second step to obtain sliding contact particles having a surface forming a sliding contact surface in sliding contact with the member to be slid. .

[10] A press-fitting machine is used in the second step, and a metal film harder than the base provided in the base of the sliding member is sandwiched between the pressurizing part of the press-fitting machine and the hard particles. The method for producing a sliding member according to [9], wherein particles are press-fitted into the base of the sliding member.

[11] The sliding member base includes a base and a surface forming portion formed on the surface of the base,
The method of manufacturing a sliding member according to [9] or [10], wherein the surface forming portion is formed by plating, thermal spraying or firing after the second step.

[12] The method of manufacturing a sliding member according to any one of [9] to [11], wherein the sliding member base includes a substrate having a hardness of Hv 200 kg/mm ² or less.

[13] The sliding member base includes a substrate having a hardness of more than Hv 200 kg/mm ² , and the first step forms recesses into which the hard particles can be inserted so as to be scattered on the surface of the substrate. forming a metal film having a hardness of Hv 200 kg/mm ² or less in the recess, and fixing the hard particles to the metal film, any one of [9] to [11] A method for manufacturing the sliding member described.

[14] The sliding member base includes a substrate having a hardness of more than Hv200 kg/mm ² , and the first step includes forming a metal film having a hardness of Hv 200 kg/mm ² or less on the surface of the substrate. are patterned so as to be scattered on the surface of the substrate, and the hard particles are fixed to the metal film.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, a sliding member capable of easily forming a sliding contact surface with sliding contact particles even if the particle size range of hard particles, which are raw materials of the sliding contact particles, is wide, and its manufacture. can provide a method.

1 is a schematic cross-sectional view showing a cross-section perpendicular to the axial direction of a shaft/bearing structure according to an embodiment of the present invention; FIG. It is the cross-sectional schematic which expanded the part enclosed with the circle in the shaft member shown in FIG. FIG. 2 is a schematic cross-sectional view of one particle, showing a cross section perpendicular to the axial direction of a shaft member in which spherical particles as hard particles are press-fitted into a base. FIG. 4 is a schematic cross-sectional view for one particle, showing a cross section perpendicular to the axial direction of a shaft member having a substantially horizontal surface at the tip of a convex portion of a sliding member base. 1 shows how hard particles, which are fixed so as to be dispersed on the surface of a substrate in the first step of the method for manufacturing a sliding member according to an embodiment of the present invention, are press-fitted into the substrate in the second step using a press-fitting machine. It is a schematic diagram shown. Schematic diagram showing a state in which a metal film harder than the substrate of the sliding member base is sandwiched between the pressurizing part of the press-fitting machine and the hard particles, and the hard particles are pressed into the sliding member base. is. FIG. 4 is a schematic cross-sectional view showing a cross section perpendicular to the axial direction of the shaft member, showing an example of a state in which hard particles are fixed to a metal film formed in recesses into which hard particles can be inserted. FIG. 4 is a schematic cross-sectional view showing a cross section perpendicular to the axial direction of the shaft member, showing an example of a state in which hard particles are fixed to a metal film patterned on the surface of a substrate. 4 is a digital photomicrograph showing that the tip of the convex portion of the base of the sliding member has a space between it and the particles in sliding contact. FIG. 4 is a schematic diagram showing how hard particles are fixed to a substrate by a conventional method.

An embodiment of the invention will be described below, but the invention is not limited thereto. The present invention is not limited to the configurations described below, and can be modified in various ways within the scope of the claims, by appropriately combining technical means disclosed in different embodiments. The resulting embodiment is also included in the technical scope of the present invention.

[Embodiment 1. Sliding member]
A sliding member according to one embodiment of the present invention is a sliding member that slides relatively to a member to be slid, and has a sliding member base and a surface of the sliding member base that is scattered with Sliding particles that are fixed and have an average particle diameter of more than 50 μm and 500 μm or less, and the tips of the hard particles have a surface that forms a sliding contact surface that makes sliding contact with the member to be slid. The surface of the base of the sliding member has a recess formed so that a portion of the sliding particles can be embedded therein, and a protrusion formed around the recess so as to surround the recess. and the sliding contact particles have a portion embedded in the recess and a portion protruding from the recess, and the protruding portion is formed around the portion protruding from the recess. It is a member.

(1-1. Shaft member as an example of sliding member)
As an example of a sliding member that slides relative to a member to be slid, a shaft member having a shaft/bearing structure in a rotating mechanism used in a pump capable of discharging slurry will be described.

In this embodiment, a shaft member as a sliding member will be described, but the sliding member according to one embodiment of the present invention is not necessarily limited to this. For example, the sliding member according to one embodiment of the present invention can also be applied to a bearing member in a shaft/bearing structure that slides relative to a shaft member.

Further, for example, the sliding member according to one embodiment of the present invention can also be applied to a sliding member such as a thrust bearing that slides in a plane relative to a member to be slid.

A configuration of a shaft member 10 as a sliding member according to one embodiment of the present invention in the shaft/bearing structure 1A will be described based on FIG. FIG. 1 is a schematic cross-sectional view showing a cross section perpendicular to the axial direction of a shaft/bearing structure 1A according to one embodiment of the present invention.

As shown in FIG. 1, the shaft/bearing structure 1A includes a shaft member 10 as a sliding member and a bearing member 11 as a member to be slid. The shaft member 10 is a cylindrical shaft sleeve. In addition, the shaft member 10 is not limited to a shaft sleeve, and may be a shaft. On the other hand, the bearing member 11 has a cylindrical shape in which the shaft member 10 is accommodated, and supports the shaft member 10 .

The bearing member 11 is made of hard ceramics, cemented carbide, or the like, for example, and has a hardness equal to or higher than that of silica sand. Furthermore, since covalent or ionic ceramics, which are hard ceramics, have a low affinity for metal components such as metal scraps rarely contained in the slurry, they are included in the slurry for the bearing member 11. It is easy to prevent adhesion of metal components such as metal scraps. In addition, the surface of the bearing member 11 may be processed to form a sintered body or film for reducing the coefficient of friction or improving wear resistance.

As shown in FIG. 1, the shaft member 10 includes a base 10a, sliding particles 10b, and a plated layer 10c, which is a surface forming portion to be described later. The base 10a and the plated layer 10c form a sliding member base 10d. However, the shaft member 10 only needs to include at least the base 10a and the sliding particles 10b. In this case, the sliding member base portion 10d consists only of the base body 10a. Note that FIG. 1 shows only a part of the sliding particles 10b.

(1-2. Sliding particles)
The sliding particles 10b are scattered and fixed on the surface of the sliding member base portion 10d. That is, the sliding particles 10b are fixed to the surface of the sliding member base portion 10d without contacting each other. The slidable particles 10b are hard particles having an average particle diameter of more than 50 μm and 500 μm or less, and the tips of the hard particles have a surface that forms a slidable surface that makes slidable contact with a member to be slid.

Each sliding contact particle 10b fixed to the surface of the sliding member base portion 10d has a surface facing the bearing member 11 and forming a sliding contact surface (surface A described above). Therefore, a sliding contact surface 12 that is a circumferential surface around the axis of the shaft member 10 is formed, and the sliding contact particles 10 b are brought into sliding contact with the bearing member 11 by the sliding contact surface 12 .

The "hard particles" are particles that are raw materials for the sliding contact particles 10b. In the present specification, the hard particles whose tip portions have the surface A are referred to as sliding contact particles. Sometimes.

The hard particles preferably have a hardness equal to or higher than that of silica sand and a compressive strength of 200 kg/mm ² or higher. According to this configuration, since the hardness is equal to or higher than that of silica sand, it is possible to prevent abrasion of the sliding contact particles 10b due to slurry particles or the like containing silica sand as a main component. Moreover, since the compressive strength is 200 kg/mm ² or more, it is easy to press-fit into the sliding member base portion 10d in the method of manufacturing a sliding member according to an embodiment of the present invention, which will be described later.

Compressive strength is the maximum stress that a material can withstand against a compressive load. The compressive strength is more preferably 250 kg/mm ² or more, further preferably 300 kg/mm ² or more, from the viewpoint that the hard particles are less likely to break during press-fitting.

Moreover, the hard particles are preferably one or more selected from the group consisting of diamond, cubic boron nitride, silicon nitride, alumina, and a composite material of WC and W2C.

Polyhedral particles with high compressive strength are readily available when the hard particles are particles selected from the group consisting of diamond, cubic boron nitride, and alumina. Moreover, when the hard particles are particles selected from the group consisting of diamond, silicon nitride, alumina, and composites of WC and W2C, spherical particles with high compressive strength are readily available.

Further, since the hard particles have a low coefficient of friction, the sliding particles 10b and the bearing member 11 can slide smoothly even under non-lubrication conditions in which no lubricant such as water exists. Furthermore, since the coefficient of friction is low, the generation of heat due to friction can be suppressed, and the durability of the shaft/bearing structure 1A can be improved.

The “tip portion” of the hard particles refers to a portion facing the bearing member 11 when the hard particles are fixed to the surface of the sliding member base portion 10d. The sliding contact particle 10b has the surface A formed at the tip portion thereof by processing the tip portion of the hard particle.

As the method of processing, a method such as grinding the tip of the hard particles with a grindstone such as diamond or silicon carbide, or performing electrical discharge machining on the tip of the hard particles can be used. A person skilled in the art can select an appropriate method for grinding a high-hardness material such as the sliding contact particles 10b in this embodiment.

When processing, the portion to be removed from the hard particles is preferably 15% or less of the average particle diameter of the hard particles, more preferably 10% or less, further preferably 5% or less, and 2%. The following are particularly preferred.

The average particle size of the hard particles is more than 50 μm and 500 μm or less.

Patent Document 1 describes electrodeposition and spark plasma sintering as methods for fixing sliding particles 10b to the surface of a substrate 10a. As described above, FIG. 10 is a schematic diagram showing how hard particles are fixed to a substrate by a conventional method, and FIG. 10(a) is a schematic diagram showing how hard particles are fixed to a substrate by electrodeposition. FIG. 10(b) is a schematic diagram showing how hard particles are fixed to a substrate by spark plasma sintering.

As described above, when the hard particles 10b are fixed to the substrate 10a by the method disclosed in Patent Document 1, as shown in FIGS. Align. However, the tips of the hard particles facing the member to be slid have a step.

Hard particles having an average particle diameter close to 500 μm have a very large level difference, and therefore require a large amount of processing when the surface A is produced. In addition, when the step is very large, there are also generated particles that are short in height and cannot be processed to form the surface A, that is, particles whose height from the surface of the substrate 10a to the tip of the hard particle 10b is short. For example, diamond particles with a mesh size of 35/45 have an average particle size of 500 μm, with the largest particle having a particle size of 540 μm and the smallest particle having a particle size of 360 μm.

When the diamond particles are fixed to the substrate 10a by the method disclosed in Patent Document 1 and 25% of the average particle diameter is ground to form the surface A, the largest particle needs to be processed to about 165 μm, and the average Particles with a particle size should be processed to 125 μm. However, the smallest particles remain unprocessed.

In the specification of the present application, the "average particle size" is a D50 value measured by a laser diffraction particle size distribution analyzer: Shimadzu Corporation SALD-2100.

(1-3. Sliding member base and sliding particles fixed to the sliding member base)
The surface of the base of the sliding member has a concave portion formed so that a portion of the sliding particles can be embedded therein, and a convex portion formed around the concave portion so as to surround the concave portion.

FIG. 2 is a schematic cross-sectional view enlarging the circled portion α in the shaft member 10 shown in FIG. In FIG. 2, 13 is a concave portion, 14 and 15 are convex portions, 16 and 16' are horizontal portions, and 17 and 18 are spaces between the convex portions and sliding contact particles. H1 to H5 represent the heights of the portions shown in the figure. The horizontal portions 16, 16' are portions forming a substantially horizontal surface in the sliding member base portion 10d. However, the sliding member base portion 10d may not have the horizontal portions 16, 16'. For example, when the sliding contact particles 10b are fixed with a narrow interval, the convex portions 14 formed around the adjacent sliding contact particles 10b are close to each other, and the horizontal portions 16, 16' may not exist. .

The "recess formed so that a part of the sliding contact particles can be embedded" means, for example, like the recess 13 shown in FIG. It is a part into which a part, not the whole, of the sliding contact particle can be fitted.

Since the plated layer 10c is formed after part of the sliding particles 10b are fitted into the concave portions 13, the concave portions 13 are formed only on the surface of the substrate 10a provided in the sliding member base portion 10d. The concave portion 13 can be formed, for example, by press-fitting hard particles, which are raw materials of the sliding particles 10b, into the base 10a by a method for manufacturing a sliding member according to an embodiment of the present invention, which will be described in detail later.

"A convex portion formed around the concave portion so as to surround the concave portion" means, for example, convex portions 14 and 15 shown in FIG. It refers to the formed part.

The protrusions 14 are formed by forming the recesses 13 in the base 10a, thereby protruding portions of the base 10a that are close to the recesses 13. As shown in FIG. The convex portion 14 can be formed, for example, by press-fitting hard particles, which are raw materials of the sliding contact particles 10b, into the base 10a by the method of manufacturing a sliding member according to one embodiment of the present invention. The protrusions 15 are formed by forming a plated layer 10c on the surface of the substrate 10a on which the protrusions 14 are formed.

As shown in FIG. 2, the sliding contact particle 10b has a portion embedded in the concave portion 13 and a portion protruding from the concave portion 13. 15 are formed. The portion protruding from the concave portion 13 refers to the portion of the sliding contact particle 10b that is not embedded in the concave portion 13. As shown in FIG. For example, it is a portion of the sliding contact particles 10b above the dashed line shown in FIG.

The depth at which the sliding particles 10b are embedded in the concave portions 13 is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more of the average particle diameter of the hard particles. . According to this configuration, it is possible to optimize the holding force of the sliding member base portion 10d for the sliding particles 10b.

Further, when hard particles are processed, the portion to be removed from the hard particles is preferably 15% or less of the average particle diameter of the hard particles, as described above. The thickness is preferably less than 85% of the average particle diameter of the hard particles, more preferably 80% or less.

The "depth at which the sliding contact particles 10b are embedded in the recesses 13" means the depth when a perpendicular line is drawn from the starting point of the recesses 13 of the substrate 10a to the deepest part of the sliding contact particles 10b fitted in the recesses 13. Refers to the length of the perpendicular (eg, H5 in FIG. 2).

By forming the protrusions 14 and 15 , the portions of the sliding particles 10 b protruding from the recesses 13 are surrounded by the protrusions 14 and 15 .

Moreover, since the convex portion 15 is the plated layer 10c formed on the convex portion 14, the surface area of the plated layer 10c is larger than when the plated layer 10c is formed only on the horizontal portion 16. FIG. Therefore, it can contribute to suppression of the moving speed of the slurry particles. Therefore, the protrusions 15 can improve the durability of the plated layer 10c against abrasion caused by the slurry particles.

However, in the shaft member 10, the plated layer 10c may not necessarily be formed. For example, when the shaft member 10 is used for applications in which abrasion due to slurry particles does not occur (for example, dry sliding), the plated layer 10c may not be formed. Therefore, when used for this purpose, the convex portion 15 may not necessarily be formed. , preferably has a substantially horizontal surface as shown in FIG. 4 to be described later.

The surface of the sliding member base portion has a horizontal portion that forms a substantially horizontal surface and is a portion other than the concave portion and the convex portion, and the height from the horizontal portion to the tip of the sliding particle is , is preferably higher than the height from the horizontal portion to the tip of the convex portion.

The above-mentioned "substantially horizontal surface" does not mean that the surface must be completely flat without any unevenness, but means that the surface can be said to be practically horizontal. For example, when hard particles are press-fitted into the base 10a by the method for manufacturing a sliding member according to one embodiment of the present invention, recesses and protrusions are not formed, and portions of the base 10a that are not affected by press-fitting are substantially horizontal. It is an aspect.

As shown in FIG. 2, the height H1 from the horizontal portion 16 to the tip of the sliding particle 10b is higher than the height H2 from the horizontal portion 16 to the tip of the convex portion . Further, the height H3 from the horizontal portion 16' to the tip of the sliding particle 10b is higher than the height H4 from the horizontal portion 16' to the tip of the convex portion 15. FIG.

As described above, the sliding member base portion 10d may not have the horizontal portions 16, 16'. In this case, the height of the portion of the sliding contact particle 10b protruding from the concave portion 13 (for example, H1, which is the height of the portion above the dashed line shown in FIG. 2) is the height of the convex portion 14 ( medium H2) and the height of the projection 15 (in the drawing, the height from the dashed line to the tip of the projection 15).

With the above configuration, the sliding particle 10b is firmly fixed to the sliding member base portion 10d by the convex portions 14 and 15, and the surface A for forming the sliding contact surface 12 is formed by the convex portions 14 and 15. Since it is positioned higher than the bearing member 11, it can slide smoothly with the bearing member 11.

(1-4. Shape of sliding member base, etc.)
In the sliding member according to one embodiment of the present invention, the tip of the convex portion provided on the surface of the sliding member base is separated from the sliding particle, and the tip of the convex portion and the sliding particle are spaced apart from each other. It is preferable to have a space between

As described above, the convex portion 14 shown in FIG. 2 is produced by press-fitting hard particles into the base 10a by, for example, the method for producing a sliding member according to one embodiment of the present invention. At this time, as shown in FIG. 2, the tip of the projection 14 (the portion having the height H2 shown in FIG. 2) has a space 17 between it and the sliding contact particle 10b.

Moreover, since the plated layer 10c is formed in the shaft member 10 shown in FIG. have

FIG. 3 is a schematic cross-sectional view of one particle, showing a cross section perpendicular to the axial direction of the shaft member 10 in which spherical particles as hard particles are press-fitted into the base 10a.

Here, spherical particles are intended to be rounded particles without corners. Spherical particles may deviate from true spheres and become elliptical or the like due to production, but the spherical particles used preferably have diameter variation and sphericity of 10 μm or less. Therefore, the shape of the surface A produced by processing the tip of the spherical particle is circular or elliptical.

As shown in FIG. 3, when the spherical particles are press-fitted, the base of the projection 14 is in contact with the sliding particle 10b, but the tip of the projection 14 has a space 17 between it and the sliding particle 10b. ing. FIG. 9 is a digital microscope photograph (equipment used: Keyence VHX5000, magnification: 200 times) showing that the tip of the projection 14 has a space 17 between it and the sliding particle 10b.

As described above, the shape of the space may vary depending on the shape of the sliding contact particle 10b.

According to this configuration, as shown in FIGS. 2 and 3, the plated layer 10c is formed so as to block the space, and the convex portion 15 is also formed. The surface area of the plated layer 10c is increased as compared with the case where the plated layer 10c is formed.

Therefore, the plated layer 10c can be made difficult to peel off, and the durability of the plated layer 10c against slurry particles and the like can be improved.

Moreover, it is also preferable that the tip of the convex portion has a substantially horizontal surface. By pressing the convex portion 14 shown in FIG. 3, for example, with a press-fitting machine, the tip of the convex portion 14 can be deformed to have a substantially horizontal surface and can be brought into close contact with the sliding particles 10b. FIG. 4 is a schematic cross-sectional view of one particle, showing a cross section perpendicular to the axial direction of the shaft member 10 in which the tips of the projections 14 have substantially horizontal surfaces.

According to the above configuration, although there is no space between the convex portions 14 and 15 and the sliding contact particles 10b, the convex portions 14 and 15 are in close contact with the sliding contact particles 10b, and the sliding contact particles 10b are removed. Since it is crimped, the sliding particles 10b can be firmly fixed to the sliding member base portion 10d. Furthermore, since the plated layer 10c having the protrusions 15 is formed, the durability of the shaft member 10 against slurry particles and the like can also be improved.

In the sliding member according to one embodiment of the present invention, the sliding member base preferably includes a substrate and a surface forming portion formed on the surface of the substrate. The surface forming portion corresponds to the plated layer 10c shown in FIGS. 1 to 4, for example.

The plated layer 10c may be formed after pressing hard particles into the substrate 10a. As a method for producing the plated layer 10c, for example, a method of electrifying in a nickel-based plating solution by an electrolysis method can be mentioned. As the plating solution, a plating solution containing a metal other than nickel and/or a plating solution containing an alloy may be used. Among them, as will be described later, it is preferable to use a plating solution capable of increasing the hardness of the plating layer 10c to Hv 400 kg/mm ² or more.

According to the above configuration, as already described, the durability of the shaft member 10 against slurry particles can be improved. Further, when the plated layer 10c is formed as the protrusions 15, as described above, the protrusions 15 have the effect of fixing the sliding particles 10b more firmly.

In addition, the surface forming portion is not limited to the plating layer formed using the plating solution. For example, the surface forming portion may be a ceramic coat. As the ceramic coat, for example, a coat formed by spraying an alumina-based material, a coat formed by spraying a cermet, a coat formed by applying an aluminum alkoxide and firing it, or the like can be used. It is also possible to use both the plated layer formed using the plating solution and the ceramic coat as the surface forming portion.

In the sliding member according to one embodiment of the present invention, it is preferable that the substrate has a hardness of Hv200 kg/mm ² or less, and the surface forming portion has a hardness of Hv400 kg/mm ² or more.

If the hardness of the substrate 10a is Hv 200 kg/mm ² or less, the hard particles can be easily press-fitted in the method of manufacturing a sliding member according to an embodiment of the present invention, which will be described later. Examples of the material of the substrate 10a having the above hardness include SUS304 and SUS304J1.

On the other hand, if the hardness of the substrate 10a is Hv200 kg/mm ² or less, the substrate 10a will be worn by the slurry particles if left as it is, so the hardness of the plated layer 10c (surface forming portion) is Hv400 kg/mm ² or more. is preferred. Examples of the material of the plated layer 10c having hardness include Ni--P and Ni--B.

From the viewpoint of easy press-fitting, the hardness of the substrate 10a is more preferably Hv 150 kg/mm ² or less. Further, the hardness of the plated layer 10c is more preferably Hv600 kg/mm ² or more from the viewpoint of wear resistance.

Further, the substrate 10a may be a substrate that has a hardness of Hv 200 kg/mm ² or less at the time of press-fitting, and is hardened by heat treatment at a temperature of 500° C. or less after press-fitting. In this case, the force with which the substrate 10a fixes the sliding particles 10b can be increased.

However, in the shaft member 10, the plated layer 10c may not necessarily be formed. For example, when the shaft member 10 is used for an application that does not cause wear due to slurry particles (for example, dry sliding), the plated layer 10c may not be formed. As mentioned above, it is preferred to have substantially horizontal surfaces.

(1-5. Surface density of sliding member, etc.)
The surface density, which is the ratio of the area occupied by the sliding particles 10b when viewed from the direction perpendicular to the surface of the substrate 10a, is preferably 20 to 70%. Here, a high areal density means that the distance between the sliding particles 10b is narrow, and conversely, a low areal density means that the distance between the sliding particles 10b is wide.

By setting the surface density to 20 to 70%, the slurry particles can easily escape to the inter-particle regions, which are the regions between adjacent sliding contact particles 10b. That is, the slurry particles that have entered between the shaft member 10 and the bearing member 11 are more likely to be fed into the inter-particle region than to be sandwiched between the sliding particles 10b and the bearing member 11 .

The slurry particles can then pass through the inter-particle regions formed on the entire outer surface of the substrate 10a and be discharged to the outside of the shaft/bearing structure 1A. As a result, wear of the bearing member 11, which is a mating member, due to the slurry particles getting caught between the sliding particles 10b and the bearing member 11 can be suppressed. The areal density is more preferably 60% or less, still more preferably 55% or less.

The shaft member 10 may include, in the inter-particle regions, particles made of the same material as the sliding particles 10b and having a smaller particle diameter than the sliding particles 10b. These particles are particles that are inevitably provided when the shaft member 10 is manufactured due to the particle size distribution of the powder that is the raw material of the sliding contact particles 10b.

[Embodiment 2. Manufacturing Method of Sliding Member]
A method for manufacturing a sliding member according to one embodiment of the present invention will be described below. For convenience of description, members having the same functions as those of the members described in the above-described embodiments are denoted by the same reference numerals, and description thereof will not be repeated.

(2-1. First step and second step)
A method for manufacturing a sliding member according to one embodiment of the present invention is a method for manufacturing a sliding member that slides relative to a member to be slid, and comprises hard particles having an average particle size of more than 50 μm and not more than 500 μm. a first step of fixing the particles so as to be scattered on the surface of the base of the sliding member; a second step of press-fitting into the base portion of the sliding member so that the thickness is substantially constant; and a third step of obtaining a sliding contact particle having a surface that contacts the surface.

In the first step, the hard particles are placed on the surface of the substrate 10a so as not to contact each other, and the hard particles are fixed to the surface by nickel plating or the like; The hard particles are applied at intervals that do not contact each other (for example, patterns of φ0.3 mm are arranged at intervals of 0.5 mm), and the hard particles are placed and fixed on the places where the adhesive is applied, to obtain a sheet. to the surface of the substrate 10a; and the like, the hard particles are fixed so as to be scattered on the surface of the substrate 10a.

FIG. 5 is a schematic diagram showing how the hard particles 10b scattered and fixed on the surface of the substrate 10a in the first step are press-fitted into the substrate 10a in the second step using a press-fitting machine. In FIG. 5, 101 is a press-fitting rod (pressing portion) of the press-fitting machine, and 104 is the base of the press-fitting machine.

As shown in FIG. 5A, when the hard particles 10b fixed to the left end of the surface of the substrate 10a are press-fitted into the substrate 10a by the press-fitting rod 101 (pressurizing portion), the press-fitting rod 101 (pressurizing portion) It descends until it abuts the base 104 and does not descend any further. Therefore, as shown in FIG. 5(b), the positions of the tips of the hard particles 10b coincide with the positions horizontal to the upper surface of the base 104. As shown in FIG.

Next, the press-fit rod 101 (pressurizing portion) is moved to press-fit the central hard particles 10b in FIG. At this time, since the tip of the first pressed hard particle 10b is aligned with the upper surface of the base portion 104, the first pressed hard particle 10b is also a guide for pressing the center hard particle 10b together with the base portion 104. can play the role of

Subsequently, the press-fit rod 101 (pressurizing portion) is moved to press-fit the hard particles 10b on the right end of FIG. 5(a). By repeating such operations, as shown in FIG. can be made

In this manner, the height of the base portion 104 is adjusted so that the height from the surface of the substrate 10a to the tip of the hard particle 10b is a desired height, and the hard particles are pressed into the base portion of the sliding member. can be press-fitted into the base of the sliding member so that the height from the surface of the hard particles to the tips of the hard particles is substantially constant.

The press-fitting is performed in an environment of 500° C. or lower. That is, the hard particles 10b and the substrate 10a to be press-fitted are placed in an atmosphere of 500° C. or less, and the press-fitting is performed as described above. From the viewpoint of workability, the press-fitting is more preferably performed in an environment of 300° C. or less, and more preferably in an environment of 200° C. or less.

As the material of the press-fit rod 101, for example, SKH51 of high speed steel can be used. The press-fitting machine is not particularly limited as long as it can perform the second step. In Examples described later, a press-fitting machine in which a rotary index is fixed on a linear guide is used.

The press-fitting machine grips the substrate 10a by means of a rotary index, uses the press-fitting rod 101 to press-fit the substrate 10a by one line in the axial direction, then finely rotates the rotary index, and moves the press-fitting position by the linear guide. can be moved to the next row and further press-fits can be made.

However, the press-fitting method is not limited to the method described above. For example, there is a method in which a hole is made in advance in a portion of the substrate 10a where the hard particles 10b are to be press-fitted, the hard particles 10b are placed in the hole, and the hard particles 10b are fixed and then press-fitted.

When the large hard particles 10b are press-fitted into the substrate 10a having high hardness, the load required for press-fitting can be reduced by adopting this method. Examples of the method for forming a hole in the above portion include machining using a machining center, chemical etching, and the like.

(2-2. Third step)
The sliding contact particle 10b has the surface A formed at the tip portion thereof by processing the tip portion of the hard particle. As described above, the tip portion can be processed by a method such as grinding the tip portion with a whetstone or performing electric discharge machining on the tip portion.

(2-3. Mode of press-fitting with a metal film sandwiched between the pressurizing part of the press-fitting machine and the hard particles)
In the method for manufacturing a sliding member according to one embodiment of the present invention, a press-fitting machine is used in the second step, and the sliding member base is provided between the pressurizing part of the press-fitting machine and the hard particles. A method in which a metal film harder than the substrate is sandwiched and the hard particles are press-fitted into the base portion of the sliding member may also be used.

FIG. 6 is a schematic diagram showing a state in which hard particles are press-fitted into the substrate 10a using the metal film. In FIG. 6, 102 is a metal film harder than the substrate 10a. A metal film 102 is sandwiched between the press-fit rod (pressurizing part) 101 shown in FIG. 10b is press-fitted into metal film 102 and base 10a, resulting in protrusion 103 on metal film 102 and protrusion 14 on base 10a.

As shown in FIG. 6, when the press-fitting is continued until the protrusions 103 and the protrusions 14 come into contact with each other, the portions of the hard particles 10b protruding from the recesses 13 are surrounded by the protrusions 14, and the substrate 10a firmly fixed to the

Since the depth of pressing hard particles 10b into metal film 102 is shallower than the depth of pressing into substrate 10a, metal film 102 can be easily separated from hard particles 10b. As a result, hard particles having protrusions extending from recesses 13 to the tips of hard particles 10b can be fixed to base 10a.

For example, when spherical particles are used as the hard particles 10b as shown in FIG. Since there is a state of point contact, the particles may break. By press-fitting using the metal film 102, the hard particles 10b are also press-fitted into the metal film 102, so that the surface pressure is dispersed. Therefore, according to the above configuration, even when spherical particles are used, it is possible to perform press-fitting without damaging the particles.

(2-4. Formation of surface formation portion)
In a method of manufacturing a sliding member according to an embodiment of the present invention, the sliding member base includes a substrate and a surface forming portion formed on the surface of the substrate, and the surface forming portion A method of forming by plating, thermal spraying, or firing after the second step may be used.

The surface forming portion is, for example, the plated layer 10c shown in FIGS. As a method of forming the surface forming portion by plating, for example, a method of electrifying the sliding member base portion that has undergone the second step in a nickel-based plating solution by an electrolysis method can be used.

Examples of the thermal spraying include thermal spraying of an alumina-based material and thermal spraying of a cermet onto the base portion of the sliding member that has undergone the second step.

As for the baking, for example, aluminum alkoxide is applied to the sliding member base that has undergone the second step, and the aluminum alkoxide after application is baked to form a film of aluminum alkoxide on the sliding member base. can be mentioned.

It is also possible to use both the plated layer formed using the plating solution and the ceramic coat as the surface forming portion. In this case, for example, the sliding member base that has undergone the second step is energized in a nickel-based plating solution by an electrolytic method, and after the energization is completed, an alumina-based material or the like is thermally sprayed. , the surface formation portion can be formed.

(2-5. Manufacturing method of sliding member according to hardness of substrate)
In the method for manufacturing a sliding member according to one embodiment of the present invention, the sliding member base preferably includes a substrate having a hardness of Hv 200 kg/mm ² or less. If the hardness of the substrate 10a is Hv 200 kg/mm ² or less, the hard particles can be easily press-fitted in the second step. As a method of press-fitting, for example, a method using the press-fitting machine described above can be mentioned.

As described above, when the hardness of the substrate 10a is Hv 200 kg/mm ² or less, a plating layer having a hardness of Hv 400 kg/mm ² or more is formed on the surface of the substrate 10a in order to prevent abrasion of the substrate 10a by the slurry particles. It is preferable to provide 10c (surface formation portion). The plated layer 10c may be formed after pressing the hard particles into the substrate 10a.

In the method for manufacturing a sliding member according to one embodiment of the present invention, the sliding member base includes a substrate having a hardness of more than Hv 200 kg/mm ² , and the first step includes inserting the hard particles. A step of forming possible recesses so as to be scattered on the surface of the substrate, forming a metal film having a hardness of Hv 200 kg/mm ² or less in the recesses, and fixing the hard particles to the metal film. There may be.

FIG. 7 is a schematic cross-sectional view showing a cross section perpendicular to the axial direction of the shaft member 10, showing an example of a state in which hard particles 10b are fixed to metal films 10e formed in recesses 13a into which hard particles 10b can be inserted. . Note that FIG. 7 shows the above state for only one particle. The concave portion 13a is also a concave portion of the sliding member base portion 10d.

When the sliding member base portion 10d includes the base body 10a having a hardness of more than Hv 200 kg/mm ² , it is difficult to press the hard particles 10b directly into the surface of the base body 10a due to the hardness.

According to the above configuration, since the hard particles 10b are press-fitted into the metal film 10e having a hardness of Hv 200 kg/mm ² or less, the press-fitting can be performed with much less labor than the case of press-fitting into the base 10a. Therefore, even when the base 10a is hard, the sliding member according to the embodiment of the present invention can be easily manufactured.

The term “recesses into which hard particles can be inserted” refers to recesses having a shape that allows a portion of the hard particles to come into contact with at least a portion of the surface when the hard particles are inserted. For example, when the hard particles are polyhedral particles, a rectangular recess in which one surface of the hard particle can be placed on the bottom surface of the recess (for example, the shape of the recess 13a shown in FIG. 7); the hard particles are spherical particles. In this case, the surface of the recess may be in surface contact with the surface of the spherical particles.

As shown in FIG. 7, the recess 13a is formed so that the hard particles 10b press-fitted into the metal film 10e formed in the recess 13a can secure a portion protruding from the recess 13a. The recesses 13a have, for example, a pore diameter larger than the average particle diameter of the hard particles 10b.

Among the hard particles having a particle diameter larger than the average particle diameter of the hard particles 10b, there may be those that cannot fit into the recesses 13a, but it is sufficient to use hard particles that can fit into the formed recesses 13a. . From the viewpoint of reducing the labor for forming the recesses 13a and the amount of the metal film 10e used, the pore size is preferably not too large compared to the average particle size of the hard particles 10b used.

Examples of methods for forming the recesses 13a include machining using a machining center and chemical etching. Further, examples of the material of the metal film 10e include nickel plating.

Examples of methods for forming the metal film 10e include electroplating and electroless plating. As described above, the metal film 10e may have a thickness that allows the hard particles 10b press-fitted into the metal film 10e to secure a portion protruding from the concave portion 13a. As a method of press-fitting the hard particles 10b into the metal film 10e, for example, a method using the press-fitting machine described above can be used.

The depth at which the hard particles 10b are embedded in the recesses 13a is preferably 50% or more and 70% or less of the average particle diameter of the hard particles 10b.

"The depth at which the hard particles 10b are embedded in the recesses 13a" is the length of a perpendicular line drawn from the starting point of the recesses 13a of the substrate 10a to the deepest part of the hard particles 10b that are embedded in the metal film 10e. (for example, H6 in FIG. 7).

Since the metal film 10e has a hardness of Hv 200 kg/mm ² or less, it is preferable to form the plated layer 10c (surface forming portion) after pressing the hard particles 10b into the metal film 10e. The hardness of the plated layer 10c (surface forming portion) is preferably Hv 400 kg/mm ² or more, as described above. The surface forming portion can be formed by the method described above.

A method for manufacturing a sliding member according to an embodiment of the present invention includes a substrate having a hardness of more than Hv200 kg/mm ² , and the first step comprises: ² or less, and patterning the metal film so as to be scattered on the surface of the substrate, and fixing the hard particles to the metal film.

FIG. 8 is a schematic cross-sectional view showing a cross section perpendicular to the axial direction of the shaft member 10, showing an example of a state in which the hard particles 10b are fixed to the metal film 10f patterned on the surface of the substrate 10a. Note that FIG. 8 shows the above state for only one particle.

When the sliding member base portion 10d includes the base body 10a having a hardness of more than Hv 200 kg/mm ² , it is difficult to press the hard particles 10b directly into the surface of the base body 10a due to the hardness.

According to the above configuration, since the hard particles 10b are press-fitted into the metal film 10f having a hardness of Hv 200 kg/mm ² or less, the press-fitting can be performed with much less labor than the case of press-fitting into the base 10a. Therefore, even when the base 10a is hard, the sliding member according to the embodiment of the present invention can be easily manufactured.

The patterning is performed to form a metal film 10f that has a surface area that allows contact with a portion of the hard particles 10b and that has a surface area and a thickness that allows a portion of the hard particles 10b to be pressed into the metal films 10f. It means to form on the surface of the substrate 10a as shown in FIG.

Examples of the material of the metal film 10f include nickel plating. Methods of forming the metal film 10f on the surface of the substrate 10a include, for example, electroplating and electroless plating.

If the metal film 10f is too thick, the thickness of the entire shaft member 10 is increased. As a method for press-fitting the hard particles 10b into the metal film 10f, for example, a method using the press-fitting machine described above can be used.

The depth at which the hard particles 10b are embedded in the metal film 10f is preferably 50% or more and 80% or less of the average particle diameter of the hard particles 10b.

"The depth at which the hard particles 10b are embedded in the metal film 10f" refers to the depth of a vertical line drawn from the horizontal portion 19 of the metal film 10f to the deepest portion of the hard particles 10b embedded in the metal film 10f. Refers to the length (for example, H7 in FIG. 8). In FIG. 8, 13b is a recess formed in the metal film 10f. In this case, since the metal film 10f also constitutes the sliding member base portion 10d, the concave portion 13b also corresponds to the concave portion of the sliding member base portion 10d.

Since the metal film 10f has a hardness of Hv 200 kg/mm ² or less, it is preferable to further provide the plated layer 10c (surface forming portion) after pressing the hard particles 10b into the metal film 10f. The hardness of the plated layer 10c (surface forming portion) is preferably Hv 400 kg/mm ² or more, as described above. The surface forming portion can be formed by the method described above.

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

The present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to these.

[Production Example 1]
Diamond particles with a particle size range of 302 to 541 μm are used as hard particles, and the difference in the amount of grinding of the hard particles required to produce the surface A is determined in the manufacture of the sliding member according to one embodiment of the present invention. A comparison was made between the case of using the method and the case of using the conventional manufacturing method.

An adhesive (Cemedine (registered trademark) Super X) was applied to a transparent PET film having a size of 266.9 mm×97 mm and a thickness of 0.2 mm in a pattern of φ0.4 mm at a pitch of 0.6 mm.

Diamond particles having a mesh size of 35/50 and an average particle diameter of 421.5 μm (manufactured by Custom Diamond, hereinafter referred to as “particles (1)”) were applied to the portion to which the adhesive had been applied, and after 1 hour, Unattached particles were removed.

The particles (1) are hard particles that are polyhedral particles and contain a tetradecahedral shape. Next, the above resin sheet was adhered and fixed to a substrate (made of SUS304) of φ85 mm×97 mmL with the above adhesive. Table 1 shows the particle size range and the like of the particles (1).

Subsequently, using a press-fitting machine equipped with a press-fitting rod (high speed steel, SKH51, HRC60), a load of 50 to 60 kg is applied per particle (1) in an environment of 25 ° C., and the surface of the substrate is Particles (1) were press-fitted (cold press-fit) into the substrate so that the height (protrusion height) from the tip of Particles (1) to the tip of Particles (1) was 100 μm.

The press-fitting machine has a rotary index fixed on a linear guide. The substrate was gripped by the rotary index, and a press-fitting rod was used to perform press-fitting for one row in the axial direction.

Next, the rotary index was slightly rotated to move the press-fitting position by 0.6 mm with the linear guide, and further press-fitting was performed. Thereafter, by repeating the same operation, all the particles (1) fixed to the substrate were press-fitted under the same conditions. As a result, protrusions corresponding to the protrusions 14 shown in FIG. 2 were formed on the substrate.

After the completion of press-fitting, the height (protrusion height) from the surface of the substrate to the tip of the particle (1) was about 100 μm. The surface of the substrate corresponds to the horizontal portion 16 in FIG.

Subsequently, the substrate was plated with nickel-phosphorus. After completion of plating, the height (protrusion height) from the surface of the plated layer formed to the tip of the particle (1) was 80 μm. As a result, protrusions corresponding to the protrusions 15 shown in FIG. 2 were formed on the substrate. The surface of the plated layer corresponds to the horizontal portion 16' in FIG.

Next, using a cylindrical grinder, the tip portion of the particle (1) was ground along the outer periphery of the substrate to prepare the surface A. The grinding amount was 42 μm. The height (projection height) from the surface of the plated layer to the surface A was 38 μm. The protrusion height corresponds to H3 in FIG.

[Production Example 2]
Particles (1) having the surface A were obtained in the same manner as in Production Example 1, except that the amount of grinding was 63 μm.

[Comparative Production Example 1]
A SUS304 sheet of 266.9 mm×97 mmL and a thickness of 0.2 mm was subjected to iron chloride etching to form holes of φ0.4 mm at a pitch of 0.6 mm. The above sheet was wrapped around the outer circumference of a substrate (made of SUS304) of Φ85 mm×97 mmL, and the same adhesive as in Production Example 1 was filled in the holes, and then the above sheet was removed.

The particles (1) used in Production Example 1 were applied to the substrate, and after 1 hour, unbonded particles were removed. Subsequently, the substrate was plated with nickel-phosphorus. After completion of plating, the height (protrusion height) from the surface of the formed plating layer to the tip of the particle (1) was 80 μm.

Next, using a cylindrical grinder, the tip portion of the particle (1) was ground along the outer periphery of the substrate to prepare the surface A. The grinding amount was 42 μm. The height (projection height) from the surface of the plated layer to the surface A was 38 μm.

[Comparative Production Example 2]
Particles (1) having the face A were obtained in the same manner as in Comparative Production Example 1, except that the grinding amount was 63 μm.

[Examples 1 and 2 and Comparative Examples 1 and 2]
For the sliding members manufactured in Production Examples 1 and 2 and Comparative Production Examples 1 and 2, the average grinding area per sliding contact particle and the average grinding amount per sliding contact particle were calculated by the following methods.

(1. Calculation of Average Grinding Area per Sliding Particle)
Eight unit surfaces (1 mm × 1 mm) are set evenly from the 100 mm × 50 mm surface of the above sliding member, and a laser microscope (product name: VK-9700, manufactured by Keyence Corporation) is used to grind each unit surface. The total sliding area and the number of particles were investigated. Based on these numerical values, the average grinding area per particle (1) was calculated.

The "ground sliding area" corresponds to the area of the surface A described above. In other words, the above-mentioned "average grinding area" corresponds to the average value of the areas of the surfaces A of the sliding particles present in each unit surface.

(2. Evaluation of grinding amount)
The surfaces of 100 mm×50 mm of the sliding members produced in Production Examples 1 and 2 and Comparative Production Examples 1 and 2 were chemically etched with sulfuric acid to dissolve nickel as the fixing layer (plating layer), and particles (1) were obtained. were collected.

Next, the volume reduced by grinding was calculated from the difference in mass between the particles (1) before grinding and the particles (1) after grinding. Furthermore, using the number of particles (1) per unit area measured by the laser microscope, the average grinding amount per particle (1) was calculated.

1 above. The average grinding area per particle (1) calculated in 2 above, and the above 2. Table 2 shows the average grinding amount per particle (1) calculated in . The "amount of grinding (%)" in the table is the ratio of the amount of grinding in each production example to the average particle diameter of the particles (1). For example, in Production Example 1, the grinding amount is 42 μm and the average particle diameter of the particles (1) is 421.5 μm, so the “grinding amount (%)” is 42/421.5≈10%. .

The manufacturing methods of Manufacturing Example 1 and Manufacturing Example 2 are methods of manufacturing a sliding member according to an embodiment of the present invention, and the manufactured sliding member is a sliding member according to an embodiment of the present invention. . Comparing Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2, even if the above-mentioned grinding amount (%) is the same, the average grinding area per particle (1) and the average grinding area per particle (1) 1 The average grinding amount per piece is significantly smaller in the example.

In Comparative Examples 1 and 2, since the method shown in Comparative Production Examples 1 and 2 is employed, as shown in FIG. Particles are fixed to the substrate. On the other hand, in Examples 1 and 2, since the method of manufacturing the sliding member according to the embodiment of the present invention shown in Production Examples 1 and 2 is adopted, the tips of the hard particles are aligned as shown in FIG. The hard particles are fixed to the substrate in this state.

It can be said that the difference in the results shown in Table 2 is based on this difference in production method. That is, it can be said that the method for manufacturing a sliding member according to an embodiment of the present invention can easily form a sliding contact surface while suppressing the amount of processing without being affected by the range of the particle size of the hard particles. .

[Examples 3 to 5 and Comparative Example 3]
In this example and a comparative example, the relationship between the fixing method of the particles in sliding contact and the holding force of the particles in sliding contact at the base of the sliding member was examined.

One diamond particle (manufactured by Custom Diamond) having a particle diameter of 400 μm is placed on the surface at the end of a φ10 mm×50 mmL substrate (made of SUS304), and a press-fit rod made of SKH51 (HRC60) is pressed from the surface of the substrate. The diamond particles were press-fitted so that the height to the tip (protrusion height) was 80 μm (Example 3).

As a result, protrusions corresponding to the protrusions 14 shown in FIG. 2 were formed on the substrate. The surface of the substrate corresponds to the horizontal portion 16 in FIG.

The diamond particles were placed at the ends of the substrate in the same manner as in Example 3, except that the height (protrusion height) from the surface of the substrate to the tip of the diamond particles was 100 μm. pressed into the surface. After press-fitting, Ni--P plating was applied (Example 4).

After completion of plating, the height (protrusion height) from the surface of the formed plating layer to the tip of the diamond grain was 80 μm.

As a result, protrusions corresponding to the protrusions 15 shown in FIG. 2 were formed on the substrate. The surface of the plated layer corresponds to the horizontal portion 16' in FIG.

Separately, on the surface at the end of a φ10 mm × 50 mmL substrate (made of SUS304), one diamond particle the same as that used in Example 3 was placed, and a press-fitting rod made of SKD11 (HRC42) was used to The height (protrusion height) from the surface of the substrate to the tip of the diamond grain was press-fitted to 80 μm (Example 5). The surface of the substrate corresponds to the horizontal portion 16 in FIG.

At this time, the diamond particles were also slightly pressed into the press-fitting rod. As a result, protrusions such as protrusions 14 shown in FIG. 2 were formed on the substrate, and the diamond particles were crimped and fixed to the substrate.

Separately, one diamond particle, which was the same as that used in Example 3, was placed on the surface of the edge of a substrate (made of SUS304) of φ10 mm×50 mm. Next, Ni plating and Ni—P plating are applied so that the height from the surface of the substrate to the tip of the diamond particle (projection height) is 80 μm, and the diamond particles are removed from the substrate without press-fitting. (Comparative Example 3).

Next, the tip of each diamond grain was ground along the outer periphery of the substrate. Grinding was carried out at a grinding speed of 85 mm/min using cemented carbide G2 as a specific abrasive. For each substrate, the grinding resistance when the diamond particles fell off was measured with a strain gauge incorporated in the grindstone, and the obtained value was defined as the holding force.

Taking the grinding resistance measured in Example 3 as 1, the grinding resistance of each diamond particle was as follows.

As shown in Table 3, in Comparative Example 3 in which press-fitting was not performed, the holding force of the hard particles at the base of the sliding member was low, making it difficult to produce the surface A described above. That is, according to the manufacturing method according to one embodiment of the present invention, the hard particles can be firmly held on the substrate, and the surface A can be stably manufactured. As a result, it is possible to provide a sliding member capable of forming a sliding contact surface that allows stable sliding contact with a member to be slid.

INDUSTRIAL APPLICABILITY The present invention is particularly suitable for a pre-standby operation pump that operates under severe conditions for the shaft/bearing structure, such as pre-operation in an anhydrous state and drainage of slurry containing earth and sand in a gas-liquid mixed state. be able to.

1A Shaft/bearing structure 10 Shaft member (sliding member)
10a... Substrate 10b... Particles in sliding contact or hard particles 10c... Plating layer (surface forming part)
10d Sliding member base 11 Bearing member (member to be slid)
REFERENCE SIGNS LIST 12 Sliding contact surface 13, 13a, 13b Concave portion of sliding member base 14, 15 Convex portion of sliding member base 16, 16′ Horizontal portion of sliding member base 17 , 18... Space between convex portion of sliding member base and sliding contact particles 19... Horizontal portion of metal film 101... Press-fit rod 102... Metal film harder than substrate H1, H3 ... Height from the horizontal part of the sliding member base to the tip of the sliding particle H2, H4 ... Height from the horizontal part of the sliding member base to the tip of the convex part of the sliding member base

Claims (12)

A sliding member that slides relatively to a member to be slid,
a sliding member base;
A surface where tips of hard particles, which are scattered and fixed on the surface of the sliding member base and have an average particle diameter of more than 50 μm and 500 μm or less, form a sliding contact surface that makes sliding contact with the member to be slid. a sliding particle having
The surface of the base of the sliding member has a concave portion formed so that a portion of the sliding contact particles can be embedded therein, and a convex portion formed around the concave portion so as to surround the concave portion,
The sliding particles have a portion embedded in the concave portion and a portion protruding from the concave portion, and the convex portion is formed around the portion protruding from the concave portion,
The surface of the sliding member base portion has a horizontal portion that forms a substantially horizontal surface and is a portion other than the concave portion and the convex portion, and the height from the horizontal portion to the tip of the sliding particle is , higher than the height from the horizontal part to the tip of the convex part,
sliding member. 2. The sliding member according to claim 1 , wherein the tip of the projection is separated from the sliding particle, and a space is provided between the tip of the projection and the sliding particle. 2. The sliding member according to claim 1 , wherein the tip of the projection has a substantially horizontal surface. 4. The sliding member according to any one of claims 1 to 3 , wherein the sliding member base comprises a substrate and a surface forming portion formed on the surface of the substrate. The sliding member according to claim 4 , wherein the substrate has a hardness of Hv200 kg/ ^mm2 or less, and the surface forming portion has a hardness of Hv400 kg/mm2 or ^more . The sliding member according to any one of claims 1 to 5 , wherein the hard particles have a hardness equal to or higher than that of silica sand and a compressive strength of 200 kg/mm2 ^or higher. 7. The hard particles according to any one of claims 1 to 6 , wherein the hard particles are one or more selected from the group consisting of diamond, cubic boron nitride, silicon nitride, alumina, and composites of WC and WC. sliding member. A method for manufacturing a sliding member that slides relative to a member to be slid,
a first step of fixing hard particles having an average particle size of more than 50 μm and not more than 500 μm so as to be dispersed on the surface of the base of the sliding member;
a second step of press-fitting the hard particles into the sliding member base in an environment of 500° C. or less so that the height from the surface of the sliding member base to the tip of the hard particles is substantially constant; ,
a third step of processing the hard particles press-fitted in the second step to obtain slidable particles having surfaces forming slidable surfaces in slidable contact with the member to be slid;
In the second step, a press-fitting machine is used, and a metal film harder than the substrate included in the sliding member base is sandwiched between the pressurizing part of the press-fitting machine and the hard particles, and the hard particles are placed in the above-described manner. press fit into the base of the sliding member;
A method for manufacturing a sliding member. The sliding member base includes a base and a surface forming portion formed on the surface of the base,
9. The method of manufacturing a sliding member according to claim 8 , wherein the surface forming portion is formed by plating, thermal spraying or firing after the second step. 10. The method of manufacturing a sliding member according to claim 8 , wherein the sliding member base includes a substrate having a hardness of Hv 200 kg/mm ^<2> or less. The sliding member base includes a substrate having a hardness of more than Hv 200 kg/mm ² , and the first step forms recesses into which the hard particles can be inserted so as to be scattered on the surface of the substrate. and forming a metal film having a hardness of Hv 200 kg /mm ² or less on the recess, and fixing the hard particles to the metal film. . The sliding member base includes a substrate having a hardness of more than Hv200 kg/mm ² , and the first step includes forming a metal film having a hardness of Hv 200 kg/mm ² or less on the surface of the substrate. 10. The method of manufacturing a sliding member according to claim 8 , wherein the step of patterning so as to be scattered on the surface of the substrate and fixing the hard particles to the metal film.

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