sliding member

Abstract

The sliding member (10) of the present application is provided with a base material (12), a porous sintered layer (14) provided on the base material (12), and a resin layer (16) impregnated in the porous sintered layer (14) and provided on the porous sintered layer (14). In the porous sintered layer (14), the porosity decreases from a second surface (S2) opposite the first surface (S1) of the base material side toward the first surface (S1) between both end surfaces in the thickness direction, and the decrease rate of the porosity in the thickness direction (Z) in a first region (E1) of 50% or more of the thickness of the porous sintered layer (14) from the second surface (S2) toward the first surface (S1) is greater than the decrease rate of the porosity in the thickness direction (Z) in a second region (E2) other than the first region (E1) of the porous sintered layer (14).

Description

Technical Field

[0001] This invention relates to a sliding member. Background Technology

[0002] It is known in the past that a porous layer is provided between the resin layer and the substrate of a sliding member.

[0003] For example, as a porous layer, a structure in which multiple granular inorganic fillers are stacked is disclosed, as well as a structure in which multiple metal particles are bonded together by solder.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2002-327750

[0007] Patent Document 2: Japanese Patent Application Publication No. 2016-108600 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, in the existing technology, it is difficult to simultaneously achieve both the ease of impregnation of the resin layer into the porous layer and the improvement of the resin layer's peel resistance relative to the substrate.

[0010] The purpose of this invention is to provide a sliding member that can balance the ease of impregnation of the resin layer into the porous sintered layer and the improvement of the peel resistance of the resin layer relative to the substrate.

[0011] Solution for solving the problem

[0012] To solve the above problems and achieve the objective, the sliding member of the present invention includes a substrate, a porous sintered layer disposed on the substrate, and a resin layer impregnated in and disposed on the porous sintered layer. Regarding the porous sintered layer, the porosity decreases from the second surface facing the first surface opposite the first surface on the substrate side toward the first surface. Furthermore, the rate of decrease in porosity in the thickness direction of a first region (50% or more of the thickness of the porous sintered layer) from the second surface toward the first surface is greater than the rate of decrease in porosity in the thickness direction of a second region other than the first region of the porous sintered layer.

[0013] Invention Effects

[0014] According to the present invention, it is possible to balance the ease of impregnation of the resin layer into the porous sintered layer and the improvement of the peel resistance of the resin layer relative to the substrate. Attached Figure Description

[0015] Figure 1This is a schematic diagram illustrating an example of a sliding member according to an embodiment.

[0016] Figure 2 This is a diagram illustrating an example of the relationship between the porosity of the porous sintered layer and its position in the thickness direction in an embodiment.

[0017] Figure 3 This is a graph showing the measurement results comparing the porosity of a porous layer with its position in the thickness direction.

[0018] Figure 4 This is a graph showing the measurement results comparing the porosity of a porous layer with its position in the thickness direction.

[0019] Figure 5 This is a diagram showing the cross-sectional view of the specimen. Detailed Implementation

[0020] Hereinafter, embodiments of the sliding member of the present invention will be described in detail with reference to the accompanying drawings.

[0021] The sliding member of this embodiment includes a substrate, a porous sintered layer disposed on the substrate, and a resin layer impregnated in and disposed on the porous sintered layer. Regarding the porous sintered layer, between its two end faces in the thickness direction, the porosity decreases from the second face opposite to the first face on the substrate side toward the first face. The rate of decrease in porosity in the thickness direction of a first region, which extends from the second face toward the first face and comprises 50% or more of the thickness of the porous sintered layer, is greater than the rate of decrease in porosity in the thickness direction of a second region of the porous sintered layer other than that first region.

[0022] Therefore, the sliding member of this embodiment can balance the ease of impregnation of the resin layer into the porous sintered layer and the improvement of the resin layer's peel resistance relative to the substrate.

[0023] The reasons for achieving the above effects are not yet clear, but are speculated as follows. However, the present invention is not limited to the following speculations.

[0024] Regarding the porous sintered layer of the sliding member in this embodiment, the porosity decreases from the second surface opposite to the first surface in the thickness direction between the two end faces. Therefore, it can be inferred that when a resin layer is formed by impregnating the resin material constituting the resin layer into the porous sintered layer, the resin material can be effectively impregnated in the pores of the porous sintered layer. Furthermore, it can be inferred that, regardless of the viscosity of the resin material, the resin layer can be effectively impregnated in the pores of the porous sintered layer.

[0025] Furthermore, regarding the porous sintered layer of the sliding member in this embodiment, the rate of decrease in porosity in the thickness direction of the first region, which extends from the second surface to the first surface and accounts for 50% or more of the thickness of the porous sintered layer, is greater than the rate of decrease in porosity in the thickness direction of the second region of the porous sintered layer, excluding the first region. Therefore, it can be inferred that, compared to cases where the rate of decrease in porosity does not satisfy the above relationship, it is possible to improve the overall adhesion between the porous sintered layer and the resin layer, and reduce the unevenness of the adhesion between the porous sintered layer and the resin layer. Thus, the resin layer can be firmly held on the substrate by the porous sintered layer, thereby improving the peel resistance of the resin layer relative to the substrate.

[0026] The sliding member of this embodiment will be described in detail below.

[0027] Figure 1 This is a schematic diagram showing an example of the sliding member 10 of this embodiment. Figure 1 The diagram schematically illustrates an example of the cross-sectional structure of the sliding member 10.

[0028] The sliding member 10 includes a substrate 12, a porous sintered layer 14, and a resin layer 16. The sliding member 10 is a laminate of the substrate 12, the porous sintered layer 14 formed on the substrate 12, and the resin layer 16 impregnated in and disposed on the porous sintered layer 14.

[0029] The substrate 12 is a layer used to provide mechanical strength to the sliding member 10. The substrate 12 is sometimes referred to as a backing metal or a backing metal layer. The substrate 12 can be, for example, a metal plate made of Fe alloy, Cu, Cu alloy, etc.

[0030] The porous sintered layer 14 is a porous layer produced by sintering.

[0031] Regarding the porous sintered layer 14 of this embodiment, between the two end faces (first face S1 and second face S2) in the thickness direction Z, from the second face S2 opposite to the first face S1 on the substrate 12 side toward the first face S1, the porosity decreases along the thickness direction Z (specifically, in the direction of arrow Z1). That is, regarding the porous sintered layer 14, the second face S2, which is furthest from the substrate 12, has the largest porosity, and the closer it is to the substrate 12, the smaller the porosity, with the first face S1, which is closest to the substrate 12, having the smallest porosity.

[0032] Furthermore, regarding the porous sintered layer 14, the rate of decrease in porosity in the thickness direction Z (specifically, the direction of arrow Z1) of the first region E1 is greater than the rate of decrease in porosity in the thickness direction Z (specifically, the direction of arrow Z1) of the second region E2.

[0033] The thickness direction Z refers to the thickness direction of the porous sintered layer 14, which is consistent with the stacking direction of the substrate 12, the porous sintered layer 14 and the resin layer 16.

[0034] Porosity represents the ratio of the total area of ​​the pores to the cross-sectional area of ​​the porous sintered layer 14. Specifically, the porosity is determined by the following method: First, the sliding member 10 is cut in a direction orthogonal to the thickness direction Z of the sliding member 10. Then, an image of the cut surface is obtained by photographing it using an electron microscope at any magnification (e.g., 100x). The image is then binarized using a known image analysis method to determine the pore areas of the porous sintered layer 14. The porosity is then calculated as the ratio of the total area of ​​the pore areas shown in the image to the total area of ​​the cut surface. By changing the cutting position in the thickness direction Z of the sliding member 10, the porosity is calculated from the cut surface at each position using the above method, thereby determining the porosity at each position in the thickness direction Z.

[0035] The first surface S1 refers to the end face on the substrate 12 side among the two end faces in the thickness direction Z of the porous sintered layer 14. Specifically, the first surface S1 is the contact surface between the porous sintered layer 14 and the substrate 12.

[0036] The second surface S2 refers to the end face opposite to the first surface S1 among the two end faces in the thickness direction Z of the porous sintered layer 14, and is the end face opposite to the substrate 12. Specifically, the second surface S2 includes the point farthest from the substrate 12 on the surface of one or more inorganic particles 18 in the porous sintered layer 14 that are located furthest from the substrate 12, and is a surface parallel to the surface of the substrate 12. The surface of the substrate 12 refers to the end face on the side of the porous sintered layer 14 and the resin layer 16 among the two end faces in the thickness direction Z of the substrate 12.

[0037] The thickness of the porous sintered layer 14 is its length in the Z-direction of thickness. Specifically, the thickness of the porous sintered layer 14 is the distance between the first surface S1 and the second surface S2 in the porous sintered layer 14. Figure 1 In the middle, refer to distance L1).

[0038] Regarding the porosity of the porous sintered layer 14, the porosity can be reduced from the second surface S2 toward the first surface S1 along the thickness direction Z (i.e., along the direction of arrow Z1). The reduction of porosity can be either a staged reduction or a continuous reduction.

[0039] The first region E1 is a region extending from the second surface S2 toward the first surface S1 (in the direction of arrow Z1) and having a thickness of 50% or more of the porous sintered layer 14. In other words, the first region E1 includes the second surface S2 of the porous sintered layer 14, and is a region extending from the second surface S2 toward the first surface S1 and having a thickness of 50% or more of the porous sintered layer 14.

[0040] It should be noted that the first region E1 is a region that is 50% or more thick from the second surface S2 toward the first surface S1 and the porous sintered layer 14, but preferably a region that is 50% or more and less than 70%, and more preferably a region that is 55% or more and less than 65%.

[0041] If the first region E1 is the region of the aforementioned range in the porous sintered layer 14, it is possible to effectively improve the peel resistance of the resin layer 16 relative to the substrate 12.

[0042] The second region E2 is the region in the porous sintered layer 14 other than the first region E1. Specifically, the second region E2 is the region in the porous sintered layer 14 that extends from the substrate 12 side face of the first region E1 to the first surface S1.

[0043] As described above, the rate of decrease in porosity in the thickness direction Z of the first region E1 is greater than the rate of decrease in porosity in the thickness direction Z of the second region E2. The rate of decrease in porosity represents the rate of decrease in porosity in the thickness direction Z (specifically, the direction of arrow Z1) from the second surface S2 toward the first surface S1, relative to the unit thickness of the porous sintered layer 14.

[0044] If the rate of decrease in porosity in the thickness direction Z of the first region E1 is greater than the rate of decrease in porosity in the thickness direction Z of the second region E2, the peel resistance of the resin layer 16 relative to the substrate 12 can be maintained, and the impregnation of the resin layer 16 into the porous sintered layer 14 can be achieved.

[0045] Figure 2 This is a diagram illustrating an example of the relationship between the porosity of the porous sintered layer 14 of the sliding member 10 in this embodiment and its position in the thickness direction Z. Figure 2 In the diagram, the vertical axis represents the porosity of the porous sintered layer 14. The horizontal axis represents the position of the porous sintered layer 14 in the thickness direction Z. Furthermore, regarding the position in the thickness direction of the horizontal axis, the thickness of the porous sintered layer 14 is 150 μm, with the position of the second surface S2 represented as 0 μm and the position of the first surface S1 represented as 150 μm.

[0046] exist Figure 2In the example shown, the change in porosity of the porous sintered layer 14 is represented, for example, by line graph 40. Line graph 40 is represented by line graphs 40A and 40B, which show different rates of decrease in porosity. The rate of decrease in porosity represented by line graph 40A is greater than the rate of decrease in porosity represented by line graph 40B. Therefore, in Figure 2 In the example shown, the first region E1 is the region of the porous sintered layer 14 with a thickness of approximately 80 μm from the second surface S2 toward the first surface S1. The second region E2 is the region of the porous sintered layer 14 with a thickness of approximately 80 μm from the second surface S2 toward the first surface S1 to a position of 150 μm from the first surface S1.

[0047] return Figure 1 Continuing the explanation, the porosity of the central portion P in the thickness direction Z of the porous sintered layer 14 is preferably 30% or more and less than 50%.

[0048] The porosity of the central portion P in the thickness direction Z of the porous sintered layer 14 is expressed as the porosity of the cut surface formed by a line passing through the center of the porous sintered layer 14 in the thickness direction Z.

[0049] The porosity of the central portion P in the thickness direction Z of the porous sintered layer 14 is preferably 30% or more and less than 50%, and more preferably 35% or more and less than 45%.

[0050] Furthermore, the porosity of the second surface S2 of the porous sintered layer 14 is higher than that of the central portion P. Specifically, the porosity of the second surface S2 is preferably 30% or more.

[0051] Furthermore, the porosity of the first surface S1 of the porous sintered layer 14 is lower than that of the central portion P. Specifically, the porosity of the first surface S1 is preferably 15% or more and 40% or less, more preferably 20% or more and 35% or less.

[0052] If the porosity of the central portion P, the first surface S1, and the second surface S2 in the thickness direction Z of the porous sintered layer 14 is within the above range, the peel resistance of the resin layer 16 relative to the substrate 12 is maintained, and the impregnation of the resin layer 16 into the porous sintered layer 14 is made easy.

[0053] The porous sintered layer 14 can be made of any material that satisfies the porosity relationship described above. For example, the porous sintered layer 14 can be composed of a sintered layer of multiple inorganic particles 18.

[0054] The porous sintered layer 14 is made, for example, by sintering multiple inorganic particles 18. The inorganic particles 18 can be any particles capable of forming the porous sintered layer 14 through sintering, and the constituent materials of the inorganic particles 18 are not limited. The inorganic particles 18 are copper-based alloys. For example, the inorganic particles 18 are pure copper, or Cu alloys such as bronze, lead bronze, and phosphor bronze, or composite materials in which FeP, Al2O3, or other powders are dispersed within these pure copper or copper alloys.

[0055] The average particle size of the inorganic particles 18 is preferably 75 μm or more and 150 μm or less, and more preferably 80 μm or more and 125 μm or less.

[0056] The average particle size of inorganic particles 18 represents the volume average particle size. Specifically, the average particle size of inorganic particles 18 refers to the value measured using a laser diffraction / scattering particle size analyzer (LS Particle Size Analyzer: LS13 320, manufactured by BECKMAN COULTER). For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volumetric cumulative distribution is plotted from the small particle size side, and the particle size that accumulates to 50% is taken as the average particle size (volume average particle size) of inorganic particles 18. 50v .

[0057] Furthermore, regarding the porous sintered layer 14, the average particle size of the inorganic particles 18 constituting the porous sintered layer 14 is within the aforementioned range, and the ratio of the thickness of the porous sintered layer 14 to the average particle size of the inorganic particles 18 is preferably 1.1 times or more and 2.2 times or less.

[0058] It should be noted that the ratio of the thickness of the porous sintered layer 14 to the average particle size of the inorganic particles 18 within the average particle size range is preferably 1.1 times or more and 2.2 times or less, and more preferably 1.3 times or more and 1.8 times or less.

[0059] If the ratio of the thickness of the porous sintered layer 14 to the average particle size of the inorganic particles 18 within the above range is within the above range, it can further effectively achieve both the improvement of the peel resistance of the resin layer 16 relative to the substrate 12 and the ease of impregnation of the resin layer 16 into the porous sintered layer 14.

[0060] Furthermore, the porous sintered layer 14 is preferably a laminate formed by stacking inorganic particles 18 in 1.1 layers or more and 2.2 layers or less, and more preferably a laminate formed by stacking inorganic particles 18 in 1.3 layers or more and 1.8 layers or less.

[0061] If the inorganic particles 18 in the porous sintered layer 14 are stacked in the above-described state, it is possible to further and effectively improve both the peel resistance of the resin layer 16 relative to the substrate 12 and the ease with which the resin layer 16 is impregnated into the porous sintered layer 14.

[0062] The inorganic particles 18 constituting the porous sintered layer 14 can be approximately the same size or different. Approximately the same size means that the particle size of one particle is within ±10% of the particle size of the other. It should be noted that, preferably, the inorganic particles 18 constituting the porous sintered layer 14 are approximately the same size.

[0063] The shape of the inorganic particles 18 is not limited. The shape of the inorganic particles 18 can be spherical, approximately spherical without sharp edges, or any other irregular shape (sheet-like, dendritic, chain-like, isotropic polyhedron, etc.).

[0064] The inorganic particles 18 constituting the porous sintered layer 14 can all be of the same shape, or they can be a mixture of particles of different shapes.

[0065] When the porous sintered layer 14 is configured to contain inorganic particles 18 of different shapes, the proportion of inorganic particles 18 with a minor axis to major axis ratio of 0.2 or more and 0.7 or less among all the inorganic particles 18 constituting the porous sintered layer 14 is preferably 50% or more, and more preferably 70% or more. Furthermore, the proportion of inorganic particles 18 with a minor axis to major axis ratio of 0.2 or less among all the inorganic particles 18 constituting the porous sintered layer 14 is preferably 30% or less, and more preferably 10% or less.

[0066] It should be noted that the thickness of the porous sintered layer 14 is preferably 0.11 mm or more and 0.22 mm or less, and more preferably 1.3 mm or more and 1.8 mm or less.

[0067] Next, resin layer 16 will be described. Resin layer 16 is a layer made of resin material. The resin material is composed of synthetic resin and additives dispersed in the synthetic resin.

[0068] The main synthetic resin used is PTFE (polytetrafluoroethylene). PFA (tetrafluoroethylene / perfluoroalkoxyethylene copolymer), FEP (perfluoroethylene propylene copolymer), low molecular weight PTFE, etc., can also be added.

[0069] The synthetic resin may contain not only PTFE, but also one or more synthetic resins selected from PI (polyimide), PAI (polyamide-imide), PBI (polybenzimidazole), PA (polyamide), phenolic resin, epoxy resin, POM (polyacetal), PEEK (polyether ether ketone), PE (polyethylene), PPS (polyphenylene sulfide), and PEI (polyether imide).

[0070] To reduce the coefficient of friction of synthetic resins and stabilize friction, additives can be added. Examples of such additives include solid lubricants such as graphite, molybdenum disulfide, tungsten disulfide, CF2, CaF2, and BN, as well as soft metals such as Pb, Bi, and Sn.

[0071] In addition, additives can be added to improve the wear resistance of synthetic resins. Such additives can be one or more selected from salts such as BaSO4, CaSO4, calcium phosphate, magnesium phosphate, and magnesium silicate; resins such as aromatic polyesters, polyimides, and PEEK; oxides such as Al2O3, FeO3, and TiO2; sulfides such as ZnS; carbides such as TiC; glass fibers; carbon fibers; and carbon.

[0072] Example

[0073] The following examples illustrate the present invention in detail, but the present invention is not limited to these examples.

[0074] Test pieces with a porous sintered layer 14 or a comparative porous layer and a resin layer 16 were prepared. The ease of impregnation of the resin layer 16 into the porous sintered layer 14 and the comparative porous layer, and the peel resistance of the resin layer 16 were evaluated for these test pieces.

[0075] - Production of the experimental film -

[0076] Step 1: A steel plate (SPCC (JIS)) with a thickness of 1.32 mm was prepared as the base material 12.

[0077] Step 2: Phosphor bronze (Cu, 6% Sn, 0.1% P) powder is dispersed on the above-mentioned substrate 12.

[0078] Step 3: Sinter the powder from Step 2 at 900℃~950℃ to produce a porous sintered layer.

[0079] Step 4: Next, mix PTFE powder and additives, and add auxiliaries to prepare a mixed powder.

[0080] Step 5: Using rollers, the synthetic resin, which is the above-mentioned mixed powder, is impregnated into the porous sintered layer.

[0081] Step 6: Dry the impregnated part obtained in Step 5 at 150℃~200℃ for about 10 minutes.

[0082] Step 7: Then, fire at 380℃~400℃ for about 10 minutes.

[0083] Through steps 1 to 7 described above, test pieces with porous sintered layers of Examples 1 to 3 and comparative test pieces with comparative porous layers of Comparative Examples 1 to 2 were produced. It should be noted that the porosity of the porous sintered layer was adjusted by changing the particle size of the powder dispersed in step 2.

[0084] Figure 2 This is a graph showing the measurement results of the relationship between the porosity of the porous sintered layer 14 of the test piece in Example 1 and its position in the thickness direction Z. Figure 2 In the diagram, the vertical axis represents the porosity of the porous sintered layer 14. The horizontal axis represents the position of the porous sintered layer 14 in the thickness direction Z. Furthermore, regarding the thickness direction of the horizontal axis, the thickness of the porous sintered layer 14 is 150 μm, the position of the second surface S2 is represented as 0 μm, and the position of the first surface S1 is represented as 150 μm.

[0085] like Figure 2 As shown, in Example 1, the change in porosity of the porous sintered layer 14 is represented by line graph 40. Line graph 40 consists of line graphs 40A and 40B. Line graph 40A represents the rate of decrease in porosity of the first region E1, and line graph 40B represents the rate of decrease in porosity of the second region E2. Figure 2 As shown, in Example 1, the first region E1 of the porous sintered layer 14 is 80% of the thickness of the porous sintered layer 14 from the second surface S2. Furthermore, the rate of decrease in porosity of the first region E1 is greater than the rate of decrease in porosity of the second region E2. Additionally, the porosity of the central portion P of the porous sintered layer 14 is 40%.

[0086] Figure 3 This is a graph showing the measurement results of the relationship between the porosity of the porous layer and its position in the thickness direction Z of the test piece of Comparative Example 1. Figure 3 In the diagram, the vertical axis represents the porosity of the porous layers being compared. The horizontal axis represents the position of the porous layers in the thickness direction Z. Furthermore, regarding the position in the thickness direction of the horizontal axis, with the thickness of the porous layers being compared being 250 μm, the position of the second surface S2 is represented as 0 μm, and the position of the first surface S1 is represented as 250 μm.

[0087] like Figure 3As shown, in Comparative Example 1, the change in porosity of the porous layer is represented by line graph 42. Line graph 42 consists of line graphs 42A and 42B. Line graph 42A represents the rate of decrease in porosity of the first region E1, and line graph 42B represents the rate of decrease in porosity of the second region E2. Figure 3 As shown, in Comparative Example 1, the first region E1 of the comparative porous layer is a region representing 20% ​​of the thickness of the comparative porous layer from the second surface S2. Furthermore, the rate of decrease in porosity in the first region E1 is greater than the rate of decrease in porosity in the second region E2. Additionally, the porosity of the central portion P of the comparative porous layer is 25%.

[0088] Figure 4 This is a graph showing the measurement results of the relationship between the porosity of the porous layer and its position in the thickness direction Z for the test piece of Comparative Example 2. Figure 4 In the diagram, the vertical axis represents the porosity of the porous layers being compared. The horizontal axis represents the position of the porous layers in the thickness direction Z. Furthermore, regarding the position in the thickness direction of the horizontal axis, with the thickness of the porous layers being compared being 150 μm, the position of the second surface S2 is represented as 0 μm, and the position of the first surface S1 is represented as 150 μm.

[0089] like Figure 4 As shown, in Comparative Example 2, the change in porosity of the porous layer is represented by line graph 44. Line graph 44 consists of line graphs 44A and 44B. Line graph 44A shows the rate of decrease in porosity of the first region E1. On the other hand, as shown in line graph 44B, line graph 44B shows that the porosity is approximately constant. Therefore, in Comparative Example 2, the second region E2 is absent. No decrease in porosity is shown.

[0090] Furthermore, in Comparative Example 2, the first region E1 of the comparative porous layer is a region representing 40% of the thickness of the comparative porous layer from the second surface S2. Additionally, the porosity of the central portion P of the comparative porous layer is 50%.

[0091] -evaluate-

[0092] —Ease of impregnation into porous sintered layers (or comparative porous layers)—

[0093] The impregnation defects in the porous sintered layer 14 and the comparative porous layer of the resin material used in the fabrication of the test pieces of the Examples and Comparative Examples were evaluated, and the evaluation results are shown in Table 1. In Table 1, the smaller the value in the "Difficulty of Impregnation Defect Generation" column, the more impregnation defects occurred. Conversely, the larger the value in the "Difficulty of Impregnation Defect Generation" column, the fewer impregnation defects occurred. In Table 1, a value of "1" in the "Difficulty of Impregnation Defect Generation" column indicates that impregnation defects occurred, "2" indicates that impregnation defects were partially generated, and "3" indicates that almost no impregnation defects occurred.

[0094] Impregnation defects can be detected by observing the cross-section of the sample. However, in the case of PTFE material, resin flow will occur during cross-sectional grinding. Therefore, after careful grinding, the cross-section is polished and observed using an electron microscope (see [reference]). Figure 5 ).

[0095] —Peel resistance of the resin layer—

[0096] The peel resistance of the resin layer 16 in the test pieces of the examples and comparative examples was evaluated.

[0097] Regarding peel resistance, the substrate 12 was fixed, and a load was applied in the thickness direction Z such that the end of the resin layer 16 in a direction orthogonal to the thickness direction Z was directed away from the substrate 12. The load at which tearing occurred was measured as the peel strength. The measurement results are shown in Table 1.

[0098] [Table 1]

[0099]

[0100] As shown in Table 1, the porosity decreases from the second surface toward the first surface S1. The rate of decrease in porosity in the thickness direction Z of the first region E1, which is from the second surface S2 toward the first surface S1 and has a porosity of 50% or more of the thickness of the porous sintered layer 14, is greater than the rate of decrease in porosity in the thickness direction Z of the second region E2. In the embodiment, compared with the comparative example that does not meet this condition, the resin layer 16 is more easily impregnated into the porous sintered layer 14, and the peel resistance of the resin layer 16 is improved.

[0101] On the other hand, in the comparative example, regarding at least one of the impregnation ease of the porous layer and the peel resistance of the resin layer 16, a lower result was obtained than that of the example.

[0102] Therefore, compared with the comparative example, the case using the porous sintered layer 14 shown in the embodiment yields the following evaluation results: it is possible to achieve both the ease of impregnation of the resin layer 16 into the porous sintered layer 14 and the improvement of the peel resistance of the resin layer 16 relative to the substrate 12.

[0103] It should be noted that the various materials and their compositions used in the above embodiments are merely examples, and the present invention is not limited thereto. The resin layer 16 of the present invention may contain unavoidable impurities. Furthermore, the specific structure of the sliding member 10 is not limited to... Figure 1 The structure is illustrated in the example.

[0104] Explanation of reference numerals in the attached figures

[0105] 10: Sliding component; 12: Substrate; 14: Porous sintered layer; 16: Resin layer; 18: Inorganic particles; S1: First surface; S2: Second surface.

Claims

1. A sliding member comprising: Substrate; A porous sintered layer disposed on the substrate; and A resin layer impregnated in and disposed on the porous sintered layer. Regarding the porous sintered layer, Between the two end faces in the thickness direction, the porosity decreases from the second face opposite to the first face on the substrate side toward the first face. The rate of decrease of the porosity in the thickness direction of the first region, which is more than 50% thick of the porous sintered layer, from the second face toward the first face is greater than the rate of decrease of the porosity in the thickness direction of the second region other than the first region of the porous sintered layer.

2. The sliding member according to claim 1, wherein, The porosity of the central portion of the porous sintered layer in the thickness direction is 30% or more and less than 50%.

3. The sliding member according to claim 1, wherein, The porous sintered layer is composed of multiple inorganic particles with an average particle size of 75 μm or more and 150 μm or less. The ratio of the thickness of the porous sintered layer to the average particle size of the inorganic particles is more than 1.1 and less than 2.

2.

4. The sliding member according to claim 3, wherein, The porous sintered layer is a laminate formed by stacking the inorganic particles in 1.1 layers or more and 2.2 layers or less.

5. The sliding member according to claim 3, wherein, The porous sintered layer has a thickness of 0.11 mm or more and 0.22 mm or less.

6. The sliding member according to claim 3, wherein, The inorganic particles are copper-based alloys.

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