JP6938086B2 - Sliding member - Google Patents

Description

The present invention relates to a sliding member including a back metal layer and a sliding layer made of an alloy and a solid lubricant.

Conventionally, as a floor board for a turnout used for a railway turnout, a floor board main body on which a rail is placed and fixed, and a flat plate-shaped sliding member provided on the floor board main body and on which a tongue rail attached to and detached from the rail is slid. The one with is known. As a sliding member such as a floor plate for a branching device, a sliding member having an oil-impregnated sintered alloy layer formed on a back metal layer is used (see, for example, Patent Documents 1 and 2). However, when a sliding member having an oil-impregnated sintered alloy layer formed as a floor plate for a branching device is used, it is necessary to periodically lubricate the oil-impregnated sintered alloy layer with lubricating oil, which requires a great deal of labor. There's a problem.

Further, as the sliding member of the floor plate for the branching device, in order to abolish the lubrication work to the sliding member or reduce the number of lubrication work, the back metal layer and the sliding layer in which a solid lubricant such as graphite is dispersed in the metal. (See, for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 5-255905 Japanese Unexamined Patent Publication No. 2014-136899 Japanese Unexamined Patent Publication No. 2000-309807

By the way, in the turnout floor plate used for a railway turnout, the sliding surface of the sliding member and the sliding surface of the mating member, Tongrail, are always in direct contact with each other. Therefore, when the bearing device in which the sliding member is used is started, sliding occurs in a state where the sliding surface of the mating member and the sliding surface of the sliding member are in direct contact with each other. When sliding occurs in such a state, the alloy near the sliding surface of the sliding member in contact with the mating member is dragged by the mating member and elastic in the moving direction (sliding direction) of the mating member. Deformation will occur. In such a situation, as in Patent Document 3, when a sliding member of the floor plate for a branching device in which particles of a solid lubricant are uniformly dispersed in an alloy of a sliding layer is used, the vicinity of the sliding surface is used. The amount of elastic deformation of the alloy is increased, and the risk of damage such as cracking on the surface of the sliding layer is increased.

The present invention has been made in view of the above circumstances, and an object of the present invention is sliding that can prevent damage such as cracks from occurring on the surface of the sliding layer when the bearing device is started. The purpose is to provide members.

In order to achieve the above object, in the invention according to claim 1, in the sliding member provided with the sliding layer on the back alloy layer, the sliding layer is composed of 1 to 15% by mass of tin and the balance. an alloy consisting of copper and unavoidable impurities, consists of a dispersed solid lubricant to the alloy, the solid lubricant has a 10% to 35% of the volume fraction of the sliding layer, sliding of the sliding layer In a cross-sectional structure perpendicular to the moving surface, when a region of 50% of the thickness of the sliding layer is defined as a sliding surface side region from the sliding surface toward the interface with the back alloy layer, the sliding layer The volume ratio of the solid lubricant dispersed in the sliding surface side region to the total volume of the solid lubricant in the solid lubricant is 20 to 40%.

In the invention according to claim 2, in the sliding member according to claim 1, the alloy further contains 0.1 to 1% by mass of P, 15 to 60% by mass of Ni, and 0.1 to 30% by mass. It is characterized by containing one or more selected from Pb, 0.1 to 16% by mass of Bi, 0.1 to 10% by mass of Ag, and 0.1 to 10% by mass of Fe.

In the invention according to claim 3, in the sliding member according to claim 1 or 2, the solid lubricant is one or more selected from graphite, molybdenum disulfide, tungsten disulfide, and boron nitride. It is characterized by that.

In the invention according to claim 1, the volume ratio of the solid lubricant dispersed in the sliding surface side region to the total volume of the solid lubricant in the sliding layer is 20 to 40%, and the interface side region (sliding from the interface). The strength (deformation resistance) of the sliding surface side region is larger than that of the region (up to 50% of the thickness of the sliding layer toward the moving surface). Therefore, when the bearing device in which the sliding member is used is started, elastic deformation occurs in the interface side region even if the sliding surface of the mating member and the sliding surface of the sliding layer are in direct contact with each other. become. Therefore, it is possible to prevent the alloy near the sliding surface in the sliding surface side region from being excessively elastically deformed in the sliding direction, and to prevent damage such as cracks from occurring on the sliding surface.

Further, the alloy contains 1 to 15% by mass of tin in order to increase the strength, but when the tin content is less than 1% by mass, the effect of increasing the strength of the alloy becomes insufficient. .. On the other hand, if the tin content exceeds 15% by mass, the alloy becomes too brittle.

The volume ratio of the solid lubricant in the sliding layer is 10 to 35%, but when the volume ratio of the solid lubricant is less than 10%, the solid in the sliding surface side region of the sliding layer. The volume ratio of the lubricant becomes too small, and the effect of enhancing the sliding characteristics (low friction) of the sliding layer becomes insufficient. On the other hand, when the volume ratio of the solid lubricant exceeds 35%, the volume ratio of the solid lubricant in the interface side region of the sliding layer becomes too large, and the strength of the sliding layer becomes too low.

When the volume ratio of the solid lubricant dispersed in the sliding surface side region to the total volume of the solid lubricant in the sliding layer is less than 20%, the strength (deformation) of the sliding surface side region and the interface side region When the difference in resistance) is too large and the sliding layer is loaded, the interface side region may be excessively elastically deformed, and cracks may occur inside the interface side region. On the other hand, when the volume ratio of the solid lubricant dispersed in the sliding surface side region to the total volume of the solid lubricant in the sliding layer exceeds 40%, the strength (deformation resistance) of the sliding surface side region and the interface side region The difference is too small to obtain the above effect.

Further, as in the invention of claim 2, the alloy further contains 0.1 to 1% by mass of P, 15 to 60% by mass of Ni, 0.1 to 30% by mass of Pb, and 0.1 to 16% by mass. It is preferable to contain one or more selected from 1% by mass Bi, 0.1 to 10% by mass Ag, and 0.1 to 10% by mass Fe. When the alloy contains one or more of P, Ni, Ag, and Fe, the sliding layer can be strengthened, and when the alloy contains one or more of Bi and Pb, the sliding layer can be strengthened. The seizure property of the sliding layer can be improved.

Further, as in the invention of claim 3, the solid lubricant is preferably one or more selected from graphite, molybdenum disulfide, tungsten disulfide, and boron nitride. By using such a solid lubricant, the sliding characteristics (low friction) of the sliding layer can be improved.

It is a schematic diagram which shows the cross section in the direction perpendicular to the sliding surface of a sliding member. It is a schematic diagram which shows the cross section in the direction perpendicular to the sliding surface of a sliding member when the back metal layer which has a surface part is used. It is a figure for demonstrating the manufacturing procedure of a sliding member. It is a figure for demonstrating the flow of the raw material powder at the time of manufacturing a sliding member. It is a figure which shows the state which the solid lubricant was dispersed in the raw material powder at the time of manufacturing a sliding member. It is a figure for demonstrating the flow of the raw material powder at the time of manufacturing a sliding member when the unevenness of the surface of a back metal layer is made small. It is a figure for demonstrating the flow of the raw material powder at the time of manufacturing a sliding member when the unevenness of the surface of a back metal layer is made large.

The sliding member 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic view showing a cross section in a direction perpendicular to the sliding surface 30 of the sliding member 1 according to the present embodiment.

As shown in FIG. 1, the sliding member 1 is provided with a sliding layer 3 on a back metal layer 2. Moreover, the sliding layer 3 has a solid lubricant 5 of 10 to 35 vol% in the alloy 4 is dispersed, the alloy 4, and 1-15 wt% of tin, the balance being copper and inevitable impurities.

The alloy 4 of the sliding layer 3 contains 1 to 15% by mass of tin in order to increase the strength. When the tin content is less than 1% by mass, the effect of increasing the strength of the alloy 4 becomes insufficient. On the other hand, if the tin content exceeds 15% by mass, the alloy 4 becomes too brittle.

The alloy 4 of the sliding layer 3 further contains 15 to 60% by mass of Ni, 0.1 to 1% by mass of P, 0.1 to 30% by mass of Pb, and 0.1 to 16% by mass of Bi, 0. It can contain one or more selected from 1 to 10% by mass of Ag and 0.1 to 10% by mass of Fe. Further, the alloy 4 of the sliding layer 3 may further contain hard particles such as ceramics and intermetallic compounds.

The ratio of the solid lubricant 5 in the sliding layer 3 is 10 to 35% by volume, but when the ratio of the solid lubricant 5 is less than 10% by volume, the sliding surface side of the sliding layer 3 will be described later. The volume ratio of the solid lubricant 5 in the region 31 becomes too small, and the effect of enhancing the sliding characteristics (low friction) of the sliding layer 3 becomes insufficient. On the other hand, when the ratio of the solid lubricant 5 exceeds 35% by volume, the volume ratio of the solid lubricant 5 in the interface side region 32 described later of the sliding layer 3 becomes too large, and the strength of the sliding layer 3 becomes low. Too much.

The solid lubricant 5 is preferably one or more selected from graphite, molybdenum disulfide, tungsten disulfide, and boron nitride.

The thickness of the sliding layer 3 (distance in the direction perpendicular to the sliding surface 30 between the sliding surface 30 and the interface 33 between the sliding layer 3 and the back metal layer 2) shall be 0.8 to 3 mm. Is preferable.

In the cross-sectional structure perpendicular to the sliding surface 30 of the sliding member 1, the thickness of the sliding layer 3 is T, and the thickness is up to 50% of the thickness T from the sliding surface 30 of the sliding layer 3 toward the interface 33. The region at the distance of is classified as "sliding surface side region 31", and the region at a distance of up to 50% of the thickness T from the interface 33 toward the sliding surface 30 is classified as "interface side region 32". The volume ratio of the solid lubricant 5 dispersed in the sliding surface side region 31 to the total volume of the solid lubricant 5 in the moving layer 3 is 20 to 40%.

In the sliding surface side region 31 of the sliding layer 3, the volume ratio of the solid lubricant 5 to the total volume of the solid lubricant 5 in the sliding layer 3 was 20 to 40%, and the solid lubricant 5 was dispersed in the interface side region 32. Since it is smaller than the volume ratio of 60 to 80% of the solid lubricant 5, the strength (deformation resistance) is larger than that of the interface side region 32. On the other hand, the interface side region 32 has a smaller strength (deformation resistance) than the sliding surface side region 31, and is more likely to be deformed.

As described above, since the strength (deformation resistance) of the sliding surface side region 31 is larger than that of the interface side region 32, when the bearing device in which the sliding member 1 is used is started, the surface of the mating member and the sliding layer 3 are started. Even if sliding occurs in a state where the sliding surfaces 30 of the above are in direct contact with each other, elastic deformation occurs in the interface side region 32. Therefore, it is possible to prevent the alloy 4 in the vicinity of the sliding surface 30 of the sliding surface side region 31 from being excessively elastically deformed in the sliding direction, and to prevent damage such as cracking from occurring in the sliding surface 30. Can be done.

With the above mechanism, the sliding member 1 according to the present invention slides even when the sliding surface 30 and the surface of the mating member are in direct contact immediately after the start of the bearing device in which the sliding member 1 is used. It is possible to prevent damage such as cracks from occurring on the surface of the moving layer 3.

Unlike the above configuration of the present invention, when a conventional sliding member dispersed so that the proportion of the solid lubricant is the same throughout the sliding layer, that is, uniformly dispersed, is used immediately after the bearing device is started. In a situation where the sliding surface of the sliding member and the mating member are in direct contact with each other, the alloy near the surface of the sliding layer in contact with the mating member is dragged by the surface of the mating member and the moving direction of the mating member (sliding). The amount of elastic deformation in the moving direction) becomes large, damage such as cracks occurs on the surface of the sliding layer, and wear is likely to occur.

Further, as described above, in the sliding surface side region 31 of the sliding layer 3, the volume ratio of the solid lubricant 5 to the total volume of the solid lubricant 5 in the sliding layer 3 is 20 to 40%. It is preferable, but it is more preferable that the volume ratio of the solid lubricant 5 is 30 to 40%.

Further, unlike the configuration of the present invention, in the sliding interface side region 31 of the sliding layer 3, the volume ratio of the solid lubricant 5 to the total volume of the solid lubricant 5 in the sliding layer 3 is less than 20%. The difference in strength (deformation resistance) between the sliding surface side region 31 and the interface side region 32 is too large, and when the sliding layer 3 is loaded, the interface side region 32 is excessively elastically deformed. Therefore, cracks may occur inside the interface side region 32. On the other hand, in the sliding surface side region 31 of the sliding layer 3, when the volume ratio of the solid lubricant 5 to the total volume of the solid lubricant 5 in the sliding layer 3 exceeds 40%, the sliding surface side region The difference in strength (deformation resistance) between 31 and the interface side region 32 is too small to obtain the above effect.

As shown in FIG. 2, the back metal layer 2 has a surface portion made of nickel or copper or an alloy composed of nickel and copper on the surface of the interface with the sliding layer 3 by a sintering method, an electroplating method, or the like. May have 6. FIG. 2 is a schematic view showing a cross section in a direction perpendicular to the sliding surface 30 of the sliding member 1 when the back metal layer 2 having the surface portion 6 is used. By providing the surface portion 6 on the surface of the back metal layer 2 in this way, the joint strength between the sliding layer 3 and the back metal layer 2 can be increased.

The sliding member 1 described above will be described in detail below along with the manufacturing process.
(1) Preparation of alloy raw materials
As the raw material of the alloy 4, an alloy powder prepared by an atomizing method having a composition of 1 to 15% by mass of tin and the balance being copper can be used. Further, a mixed alloy powder of copper powder and tin powder prepared by an atomizing method or an electrolysis method adjusted so that the composition is 1 to 15% by mass of tin and the balance is copper may be used. Further, the alloy powder and the mixed alloy powder further include 0.1 to 1% by mass of P, 15 to 60% by mass of Ni, 0.1 to 30% by mass of Pb, and 0.1 to 16% by mass of Bi. The composition may contain one or more selected from 0.1 to 10% by mass of Ag and 0.1 to 10% by mass of Fe.

(2) Preparation of Solid Lubricant Raw Material As the raw material of the solid lubricant 5, one or more selected from graphite, molybdenum disulfide, tungsten disulfide, and boron nitride can be used. The raw material of the solid lubricant 5 preferably has an average particle size of 100 to 350 μm.

(3) Back metal The back metal layer 2 (strip steel 9) includes subeutectoid steel containing carbon with a carbon content of 0.1 to 0.6% by mass, austenite-based stainless steel, high-strength steel, and maraging steel. Such as iron alloys and copper alloys can be used. Further, the surface of the back metal layer 2 is provided with irregularities having a maximum height (ISO4287-197) of Rz20 to 100 μm by machining or the like. The uneven direction is an arbitrary direction. Further, as shown in FIG. 2, the back metal layer 2 has a surface portion made of nickel or copper or an alloy composed of nickel and copper on the surface of the interface with the sliding layer 3 by a sintering method, an electroplating method, or the like. May have 6. In such a configuration, the thickness of the surface portion 6 is set to 1 to 50 μm, and the surface after the formation of the surface portion 6 is provided with irregularities of Rz 20 to 100 μm.

(4) Organizational Control FIG. 3 schematically shows a manufacturing process of the sliding member 1 according to the present embodiment. As shown in FIG. 3, in the process of moving the strip steel 9 (back metal layer 2) from the uncoiler 7 to the coiler 13, first, the raw material powder 8 in which the alloy powder and the solid lubricant 5 are mixed is mixed with the strip steel 9 (back metal). Spray on layer 2). Then, the raw material powder 8 sprayed on the strip steel 9 (back metal layer 2) is lined with the liner 10 set at a predetermined interval with respect to the strip steel 9 (back metal layer 2) to a predetermined thickness, and 1 Next sintering, primary rolling, secondary sintering, and secondary rolling are sequentially performed to finish to a predetermined thickness.

More specifically, as the raw material powder 8 in which the alloy powder and the solid lubricant 5 are mixed, the average particle size of the alloy powder is 1 to 63 μm, and the average particle size of the solid lubricant 5 is larger than the average particle size of the alloy powder. It needs to be large. The shape of the solid lubricant 5 may be spherical or lumpy, but is preferably scaly or flat. Such raw material powder 8 is uniformly sprayed on the back metal layer 2 coated with the adhesive layer to a predetermined thickness.

Further, as shown in FIG. 4, when the raw material powder 8 comes into contact with the liner 10, convection occurs between the back metal layer 2 and the liner 10. Then, as shown in FIG. 5A, when the surface roughness of the back metal layer 2 is Rz20 to 100 μm, the solid lubricant 5 is uniform on the raw material powder 8 before the raw material powder 8 passes through the liner 10. However, as shown in FIG. 5 (b), after the raw material powder 8 has passed through the liner 10, the solid lubricant 5 having a large particle size among the confluent raw material powder 8 is added to the back metal layer 2. It is caught in the unevenness of the surface of the surface, and is denser in the interface side region 32 than in the sliding surface side region 31. After that, a sintering step and a rolling step are performed. In the sintering step and the rolling step, the solid lubricant 5 does not move to the sliding side region 31, and the sliding layer 3 after the sintering step and the rolling step. In addition, the solid lubricant 5 is distributed more in the interface side region 32 than in the sliding surface side region 31.

As shown in FIG. 6, when the surface roughness of the back metal layer 2 is less than Rz 20 μm, the solid lubricant 5 does not get caught in the unevenness of the surface of the back metal layer 2 when the raw material powder 8 passes through the liner 10. , The ratio of the solid lubricant 5 in the interface side region 32 cannot be increased as compared with the sliding surface side region 31. On the other hand, as shown in FIG. 7, when the surface roughness of the back metal layer 2 exceeds Rz 100 μm, when the raw material powder 8 passes through the liner 10, it is alloyed with the solid lubricant 5 in the recesses on the surface of the back metal layer 2. The powder is entrained, and the proportion of the solid lubricant 5 in the interface side region 32 cannot be increased as compared with the sliding surface side region 31.

Then, after the raw material powder 8 has passed through the liner 10, the sintering furnace 11 is used as the primary sintering, and the powders are sintered at a temperature of 800 to 1000 ° C. for 10 to 30 minutes in a reducing atmosphere. And the back metal layer 2 are joined to form a sintered alloy layer. After that, a rolling mill 12 is used as the primary rolling, and the rolled alloy layer is densified and the thickness is adjusted by rolling. Then, in order to increase the densification and the bonding strength to the back metal layer 2, it is again sintered in a reducing atmosphere at a temperature of 800 to 1000 ° C. for 10 to 30 minutes (secondary sintering) and rolled by a roll (2). Next rolling) is repeated.

In the conventional manufacturing process of the sliding member 1, a back metal layer 2 having a smooth surface as an interface with the sliding layer 3 is used. When such a smooth back metal layer 2 is used, the surface thereof is not uneven, so that when the raw material powder 8 passes through the liner 10, the solid lubricant 5 does not get caught on the surface of the back metal layer 2 and is on the sliding surface side. The proportion of the solid lubricant 5 in the interface side region 32 cannot be increased as compared with the region 31. Further, when the surface of the back metal layer 2 which is the interface with the sliding layer 3 has a porous metal portion which does not contain the solid lubricant 5, the unevenness of the porous metal portion exceeds 100 μm. When the raw material powder 8 passes through the liner 10, the alloy powder is involved together with the solid lubricant 5, and the ratio of the solid lubricant 5 in the interface side region 32 is increased as compared with the sliding surface side region 31. Can't.

Next, a method of separating the sliding surface side region 31 and the interface side region 32 in the sliding layer 3 will be described. First, using an electron microscope, electron images of a plurality of locations (for example, five locations) in a cross section perpendicular to the sliding surface 30 of the sliding member 1 are photographed at a magnification of 200. The photographing magnification of the electronic image is not limited to 200 times, and may be changed to another magnification. Using this photographed image, the thickness T in the direction perpendicular to the sliding surface 30 of the sliding layer 1 is obtained. Further, a virtual line CL parallel to the sliding surface 30 is located at a position that is 50% of the thickness T (1/2 × T) toward the back metal layer 2 side from an arbitrary position of the sliding surface 30. Draw. The area between the sliding surface 30 of the sliding layer 3 and the virtual line CL is the sliding surface side region 31, and the area between the interface 33 of the sliding layer 3 with the back metal layer 2 and the virtual line CL is the interface side region. It is set to 32.

Further, a method for measuring the volume ratio of the solid lubricant 5 dispersed in the sliding surface side region 31 with respect to the total volume of the solid lubricant 5 in the sliding layer 3 will be described. Using the captured image of the electronic image obtained by the above method, a general image analysis method (for example, analysis software: Image-Pro Plus (Version 4.5); manufactured by Planetron Co., Ltd.) is used in the captured image. The total area of the solid lubricant 5 in the sliding layer 3 and the total area of the solid lubricant 5 dispersed in the sliding surface side region 31 were measured, and from those measured values, the solid lubricant in the sliding layer 3 was measured. The area ratio of the solid lubricant 5 dispersed in the sliding surface side region 31 to the total area of 5 is calculated. This area ratio corresponds to the volume ratio.

Next, with respect to the sliding member 1 having the back metal layer 2 and the sliding layer 3 according to the present embodiment, Examples 1 to 16 and Comparative Examples 17 to 21 were produced as shown below. The composition of the sliding layer 3 of the sliding members 1 of Examples 1 to 16 and Comparative Examples 17 to 21 is as shown in Table 1. In Examples 1 to 16, the alloy powder produced by the atomizing method and the solid lubricant 5 were mixed using a general mixer to obtain the component ratios shown in Table 1, and the "back metal layer surface" in Table 1 was obtained. The unevenness shown in the "Roughness Rz (μm)" column was sprayed on the back metal layer 2 provided on the surface, and sintering and rolling were repeated to manufacture the sliding member 1. Further, the sliding material 1 was processed into a plate shape to prepare a test piece.

In Comparative Examples 17 and 18, after changing the size of the unevenness on the surface of the back metal layer 2, the sliding material 1 was manufactured so as to have the component ratios shown in Table 1 by the same method as the manufacturing method of the above-mentioned Examples. bottom. Further, the sliding material 1 was processed into a plate shape to prepare a test piece.

In Comparative Example 19, the alloy powder was prepared by an atomizing method so as to have the components shown in Table 1. Then, the produced alloy powder and the solid lubricant 5 are mixed using a general mixer, sprayed on the back metal layer 2 having irregularities on the surface so as to have the component ratios shown in Table 1, and sintered. The sliding member 1 was manufactured by repeating rolling. Further, the sliding material 1 was processed into a plate shape to prepare a test piece.

In Comparative Examples 20 and 21, the mixing ratios of the alloy powder and the solid lubricant 5 were mixed so as to be the components of Table 1, and the component ratios of Table 1 were obtained by the same method as the production method of the above-mentioned Examples. Sliding material 1 was manufactured. Further, the sliding material 1 was processed into a plate shape to prepare a test piece.

In addition, a reciprocating sliding test was conducted on Examples 1 to 16 and Comparative Examples 17 to 21 under the conditions shown in Table 2. The results are shown in Table 1. Further, the presence or absence of cracks was determined from the appearance of the sliding layer 3 after the reciprocating sliding test.

In Examples 1 to 16, the surface of the sliding layer 3 is not cracked. Further, as a result of suppressing the occurrence of cracks on the surface of the sliding layer 3, the amount of wear is also reduced. This is a solid in which the volume ratio of the solid lubricant 5 in the sliding layer 3 is 10 to 35% and is dispersed in the sliding surface side region 31 with respect to the total volume of the solid lubricant 5 in the sliding layer 3. Since the volume ratio of the lubricant 5 is 20 to 40%, the strength (deformation resistance) of the sliding surface side region 31 is larger than that of the interface side region 32, and the vicinity of the sliding surface 30 of the sliding surface side region 31 This is because the alloy 4 of the above is suppressed from being excessively elastically deformed in the sliding direction.

In Example 6, the surface roughness of the back metal layer 2 was reduced to Rz 20 μm as compared with Example 1, but the surface of the sliding layer 3 was not cracked as in Example 1. Further, in Example 7, the surface roughness of the back metal layer 2 was increased to Rz 100 μm as compared with Example 1, but the surface of the sliding layer 3 was not cracked as in Example 1.

_{Example 8 contains MoS 2} as the solid lubricant 5 as compared with Example 1 which contains graphite as the solid lubricant 5, but the surface of the sliding layer 3 is cracked as in Example 1. It has not occurred.

Compared with Example 1, Example 9 contains as much as 15% by mass of Sn for strengthening the alloy , but as in Example 1, cracks are not generated on the surface of the sliding layer 3. Further, by strengthening the sliding layer 3, the amount of wear is lower than that of the first embodiment.

Examples 10 to 13 and 16 contain one or more selected from P, Ni, Fe, and Ag that strengthen the alloy as compared with Example 1, but the sliding layer is the same as in Example 1. No cracks have occurred on the surface of 3. Further, by strengthening the sliding layer 3, the amount of wear is lower than that of the first embodiment.

Examples 14 and 15 contain Pb and Bi, respectively, which improve seizure property as compared with Example 1, but the surface of the sliding layer 3 is not cracked as in Example 1. ..

In Comparative Example 17, the surface roughness of the back metal layer 2 was reduced to less than Rz 20 μm as compared with Example 1. Therefore, as described above, when the raw material powder passed through the liner 10, the solid lubricant 5 was applied to the back metal layer 2. The proportion of the solid lubricant 5 in the interface side region 32 cannot be increased as compared with the sliding surface side region 31 without being caught by the unevenness of the surface of the surface. Therefore, during the sliding test, the alloy 4 near the sliding surface 30 in the sliding surface side region 31 is excessively elastically deformed in the sliding direction, and the surface of the sliding layer 3 is cracked. .. Further, as a result of cracks occurring on the surface of the sliding layer 3, the amount of wear is also large.

In Comparative Example 18, the surface roughness of the back metal layer 2 exceeds Rz 100 μm as compared with Example 1. Therefore, as described above, when the raw material powder passes through the liner 10, it is solid in the recess on the surface of the back metal layer 2. Since the alloy powder is involved together with the lubricant 5, the proportion of the solid lubricant 5 in the interface side region 32 cannot be increased as compared with the sliding surface side region 31. Therefore, during the sliding test, the alloy 4 near the sliding surface 30 in the sliding surface side region 31 is excessively elastically deformed in the sliding direction, and the surface of the sliding layer 3 is cracked. .. Further, as a result of cracks occurring on the surface of the sliding layer 3, the amount of wear is also large.

Compared with Example 1, Comparative Example 19 does not contain Sn that reinforces the alloy , so that the strength of the sliding layer 3 is low and the surface of the sliding layer 3 is cracked. Further, as a result of cracks occurring on the surface of the sliding layer 3, the amount of wear is also large.

In Comparative Example 20, since the volume ratio of the solid lubricant 5 in the sliding layer 3 was reduced to less than 10% as compared with Example 1, the effect of improving the sliding characteristics (low friction) of the sliding layer 3 was obtained. It becomes insufficient and cracks are generated on the surface of the sliding layer 3. On the other hand, in Comparative Example 21, since the volume ratio of the solid lubricant 5 in the sliding layer 3 exceeds 35% as compared with Example 1, the solid lubricant 5 in the interface side region 32 of the sliding layer 3 The volume ratio becomes too large, the strength of the sliding layer 3 becomes too low, and the surface of the sliding layer 3 is cracked. Further, as a result of cracks occurring on the surface of the sliding layer 3, the amount of wear is also large.

The sliding member 1 of the present invention is not limited to a flat plate-shaped sliding member such as a floor plate for a branching device used in a railway branching device, and is not limited to a cylindrical journal bearing that supports a radial load on the rotating shaft of various bearings. It can be applied to thrust bearings of any shape that support the axial load of the rotating shaft.

1 Sliding member 2 Back metal layer 3 Sliding layer 4 Alloy 5 Solid lubricant 6 Surface part 7 Uncoiler 8 Raw material powder 9 Stripped steel 10 Liner 11 Sintering furnace 12 Roller 13 Koyler 30 Sliding surface 31 Sliding surface side area 32 Interface side region 33 Interface

Claims (3)

In a sliding member provided with a sliding layer on the back metal layer,
The sliding layer is composed of a alloy 1-15 wt% of tin, the balance being copper and inevitable impurities, and dispersed solid lubricant to the alloy, the solid lubricant, 10 of the sliding layer Has a volume ratio of ~ 35%,
In the cross-sectional structure perpendicular to the sliding surface of the sliding layer, a region of 50% of the thickness of the sliding layer from the sliding surface toward the interface with the back metal layer is defined as a sliding surface side region. When, the sliding member is characterized in that the volume ratio of the solid lubricant dispersed in the sliding surface side region to the total volume of the solid lubricant in the sliding layer is 20 to 40%. The alloy further contains 0.1 to 1% by mass of P, 15 to 60% by mass of Ni, 0.1 to 30% by mass of Pb, 0.1 to 16% by mass of Bi, and 0.1 to 10% by mass. The sliding member according to claim 1, further comprising one or more selected from% Ag and 0.1 to 10% by mass Fe. The sliding member according to claim 1 or 2, wherein the solid lubricant is one or more selected from graphite, molybdenum disulfide, tungsten disulfide, and boron nitride.

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