JP4389026B2 - Sliding material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sliding material formed by providing a coating layer on a base material and a method for manufacturing the same, and more particularly to a material in which the structure of the coating layer is improved to improve bearing characteristics.

  Slide bearings used for internal combustion engines of automobiles and general industrial machines are required to have excellent non-seizure properties in addition to excellent bearing characteristics, specifically excellent fatigue resistance. Conventionally, the sliding bearing for the internal combustion engine includes an aluminum-based alloy sliding bearing using an Al alloy as a bearing alloy, a copper-based alloy sliding bearing using a Cu alloy as a bearing alloy, and these aluminum-based alloy sliding bearings and copper. There are slide bearings with an overlay layer on the surface of the bearing alloy layer of the base alloy slide bearing, and each is properly used according to the usage environment.

  The aluminum-based alloy sliding bearing and the copper-based alloy sliding bearing described above are manufactured from a bimetal in which a bearing alloy is lined on a back metal. For example, in an aluminum-based alloy plain bearing, an Al alloy plate is first manufactured by casting and rolling an Al alloy. Then, the Al alloy plate is superposed on the carbon steel strip and roll-welded to form a bimetal composed of a back metal layer and an Al alloy layer. Thereafter, the bimetal is machined to form a semi-cylindrical or cylindrical slide bearing.

  In this aluminum-based alloy sliding bearing, an Al—Sn-based alloy is usually used as the Al alloy. Since Al and Sn are metals that are phase-separated from each other, they do not make a solid solution or only a small amount. Therefore, as shown in FIG. 4, the cast structure is in a form in which the Sn phase is dispersed as relatively large crystal particles 14 in the Al matrix 12.

In this way, in the Al alloy cast structure, the soft Sn phase exists as relatively large particles, so in the aluminum-based alloy slide bearing in which the bearing alloy layer is manufactured by casting, foreign matter embeddability and conformability, and consequently Excellent non-seizure property. However, since the size of the Sn phase present in the Al matrix is large, it may work disadvantageously in terms of mechanical strength, and further fatigue resistance is required.
In order to improve the fatigue resistance of this Al alloy, for example, it is conceivable to apply the thermal spraying technique disclosed in Patent Document 1. Patent Document 1 describes that Al or an Al alloy is sprayed on a swash plate in order to improve the wear resistance of the swash plate of the swash plate compressor.
Japanese Patent Laid-Open No. 2001-20856

  When the technology described in Patent Document 1 is applied to an aluminum-based alloy plain bearing, an Al alloy layer is formed by depositing Al alloy particles on the surface of the back metal by thermal spraying, or an Al alloy layer is formed on the surface of the bearing alloy layer made of an Al alloy. The particles are adhered by thermal spraying to form an overlay layer. Then, as shown in FIG. 5, the structure of the bearing alloy layer or overlay layer deposited by thermal spraying has a form in which small-sized Sn phase 18 is dispersed in the Al matrix 16, so that the hardness is high and mechanical. It is considered that the structure is excellent in strength and the wear resistance and fatigue resistance are improved.

  However, since the structure obtained by thermal spraying does not have a large Sn phase, it may be disadvantageous in terms of foreign material embeddability and conformability, and further non-seizure properties are required.

  On the other hand, in a copper base alloy bearing, a Cu alloy powder for sintering is dispersed on a carbon steel strip and sintered at a high temperature of about 800 ° C. to form a bimetal composed of a back metal layer and a Cu alloy layer. Then, the bimetal is machined to form a half or cylindrical slide bearing. In a copper-based alloy plain bearing, after forming in a half shape or a cylindrical shape, an overlay layer is formed by electroplating an Ag-Pb-based Ag alloy on the surface of the Cu alloy layer.

  However, since this overlay layer is formed by electroplating, fine Pb is dispersed in Ag. Such an overlay layer is excellent in wear resistance and fatigue resistance, but since there is no large phase of Pb which is a soft metal, as in the case of thermal spraying described above, in terms of foreign matter embedment and conformability. There is a case where it works disadvantageously and further non-seizure property is required.

As described above, with conventional sliding bearings (sliding materials), it has been difficult to obtain a sliding bearing having excellent anti-seizure properties while maintaining fatigue resistance.
Therefore, an object of the present invention is to provide a sliding material excellent in non-seizure property while maintaining fatigue resistance, and a method for producing the same.

  In order to achieve the above object, in the present invention, in a sliding material having a base material and a coating layer formed on the base material, the coating layer includes two or more metal components that are phase-separated from each other. An alloy particle comprising at least two metal components having a difference in hardness among the two or more metal components to be phase-separated, and the hardest metal component among the at least two metal components constituting the alloy particle The alloy particles have a structure in which soft metal particles composed of non-metallic components are present together, and the alloy particles have dispersed phases composed of metal components that are not the hardest metal components dispersed in the alloy particles. It is characterized by.

  As shown in FIG. 2, the sliding material has a structure in which a bearing alloy layer 2 is formed on the back metal layer 1, and an overlay on the bearing alloy layer 2 on the back metal layer 1 as shown in FIG. Some have a structure in which the layer 3 is formed. The present invention is intended for both of these sliding materials. In the structure shown in FIG. 2, the back metal layer 1 corresponds to the base material, and the bearing alloy layer 2 corresponds to the coating layer. In the structure of FIG. 3, the bearing alloy layer 2 corresponds to the base material, and the overlay layer 3 corresponds to the coating layer. The alloy used as the bearing alloy layer 2 is mainly an Al alloy or a Cu alloy, and the overlay layer 3 is an Ag alloy or the like in addition to an Al alloy and a Cu alloy.

<Metal components that undergo phase separation>
Examples of metal components to be phase-separated include Si, Sn, Pb, In, and Bi with respect to Al, Pb and Bi with respect to Cu, and Pb and Bi with respect to Ag. The metal component constituting the coating layer includes, of course, those composed only of the phase-separated metal component, but can be a solid solution metal component (for example, Cu, Si, Zn, Cu, etc. with respect to Al, Cu Sn, Ni, Zn, etc., and Ag, Sn, Zn, etc.) may be contained.

<Alloy particles>
Examples of alloy particles include Al alloys added with Sn, Pb, In, Bi, etc., Cu alloys added with Pb, Bi, etc., Ag alloys added with Sn, Zn, etc. as soft metal components forming the dispersed phase. is there.
The alloy particles form a metal component that forms a solid solution with a metal component that forms a matrix such as Al, Cu, or Ag, in other words, a metal component that does not phase separate, or a dispersed phase such as Sn, Pb, In, or Bi. The metal component and the metal component which makes a solid solution may be included.

Examples of combinations of metals constituting the alloy particles include the following.
(1) Al alloy particles Al—Sn, Al—Pb, Al—Bi, Al—Sn—Pb, Al—Sn—Cu, Al—Sn—Si, Al—Sn—Cu—Si, Al—Pb—Zn, Al-Pb-Zn-Si, Al-Sn-Al 2 O 3, Al-Sn-SiC like.
(2) Cu alloy particles Cu—Pb, Cu—Pb—Sn, Cu—Pb—Sn—Ni, Cu—Pb—Zn, Cu—Pb—Si, Cu—Bi, Cu—Bi—Sn, Cu—Bi— Si, Cu—Bi—Zn, Cu—Pb—Al ₂ O _{3 and the} like.
(3) Ag alloy particles Ag—Pb, Ag—Bi, Ag—Pb—Bi, Ag—Sn—Pb, Ag—Zn—Pb, Ag—Pb—Si, Ag—Bi—Al ₂ O _{3 and the} like.

<Soft metal particles>
The soft metal particles are composed of the hardest metal component among the metal components constituting the alloy particles. Preferably, it is composed of the softest metal component. Examples of the metal component include Sn, Pb, and Bi. The soft metal particles may be an alloy. The soft metal particles are the same as the metal components constituting the dispersed phase contained in the alloy particles. The soft metal particles are preferably 5 to 30 HV, and more preferably 10 HV or less.

  According to the sliding material of the present invention, the alloy particles and soft metal particles as described above coexist in the coating layer, and the dispersed phase composed of the hardest metal component is dispersed in the alloy particles. is doing. For this reason, a relatively soft metal component is finely present in the alloy particles as a dispersed phase and is also present as a relatively large particle separately from the alloy particles. Therefore, by dispersing the soft metal component finely The lubrication action can prevent seizure against local metal contact with the counterpart material while suppressing the decrease in strength and maintaining fatigue resistance, and the large soft metal particles can ensure foreign matter embedment and conformability. Excellent non-seizure properties can be obtained.

  As a specific example, the coating layer includes Al and Sn that are phase-separated from each other, and has a structure in which both alloy particles composed of Al and soft Sn and soft metal particles containing only Sn exist. A fine Sn dispersed phase is dispersed in the alloy particles. For this reason, Sn finely disperses in the alloy particles, thereby preventing seizure against local metal contact with the counterpart material due to the lubricating action of Sn, while suppressing a decrease in strength and providing good fatigue resistance. Can be maintained. Further, the Sn soft metal particles present in relatively large particles can ensure the foreign matter embedment property and the conformability, and can obtain excellent non-seizure properties.

  The present invention is important for the inventors to control the film (coating layer) structure, particularly the size and shape of particles and phases, in order to improve the non-seizure property while maintaining the fatigue resistance of the sliding material. Excellent non-seizure while maintaining good fatigue resistance using a cold spray method different from conventional coating layer manufacturing methods (casting method, thermal spraying method, electroplating method, PVD (physical vapor deposition) method) By getting sex. So far, manufacturing conditions for controlling the structure have not been established, but the present inventors have established a sliding material having excellent non-seizure properties while maintaining good fatigue resistance. It became so.

In the sliding material of the present invention, the alloy particles and soft metal particles preferably have a particle length in the direction perpendicular to the thickness direction longer than the particle length in the thickness direction of the coating layer.
The counterpart material slides on the surface of the coating layer. If the length of the alloy particles and soft metal particles is longer than the direction along the sliding direction of the mating material (the direction perpendicular to the thickness direction of the coating layer, that is, the direction along the surface of the sliding layer), the soft metal The component easily spreads on the surface of the coating layer, and foreign matter embedment and conformability, and hence non-seizure properties are further improved.

In the sliding material of the present invention, the dispersed phase in the alloy particles is preferably smaller than the soft metal particles.
Since the soft metal component in the alloy particles is a finer dispersed phase than the soft metal particles, it is possible to efficiently suppress a decrease in the strength of the alloy particles. The alloy particles having high strength of the present invention can sufficiently withstand the load of the counterpart material even when the counterpart material is in local contact, and the fatigue resistance of the sliding material is improved. And since the soft metal component is dispersed uniformly in a finer dispersed phase than the soft metal particles, the non-seizure property of the sliding material is improved by its lubricating action.
In this case, the size of the dispersed phase is preferably 4 μm or less from the viewpoint of improving the fatigue resistance, wear resistance, and non-seizure properties.

It is preferable that pores exist in the coating layer.
When pores are present in the coating layer, non-seizure properties are improved due to an oil reservoir effect.
In consideration of mechanical strength, the pores are preferably smaller than the dispersed phase.

  In the present invention, the coating layer includes both alloy particles, soft metal particles, and hard metal particles made of a metal component that is not the softest metal component among at least two kinds of metal components constituting the alloy particles. Can be organized.

The metal component of the hard metal particle is a metal component contained in the alloy particle, and is a metal component that is not the softest metal component among the metal components constituting the alloy particle. Preferably, it is composed of the hardest metal component. Examples of the metal component include Al, Cu, Ag, Zn, Sb, and Si. The hard metal particles may be an alloy. The metal component of the hard metal particles is preferably the metal component of the main component of the alloy particles. The hard metal particles are preferably 20 to 400 HV, and more preferably 100 HV or more. Further, the Vickers hardness of the hard metal particles is preferably 2 to 100 times, more preferably 3 to 20 times the Vickers hardness of the soft metal particles.
Thus, abrasion resistance improves because hard metal particles are contained in the coating layer.

The soft metal particles are preferably uniformly distributed in the coating layer in order to further improve the non-seizure property and foreign matter burying property of the coating layer.
The hard metal particles are also preferably uniformly distributed in the coating layer in order to further improve the wear resistance of the coating layer.
In order to improve the strength of the coating layer, the alloy particles preferably have an average circumscribed sphere diameter of 70 μm or less. The soft metal particles preferably have an average circumscribed sphere diameter of 70 μm or less. Further, the hard metal particles preferably have an average circumscribed sphere diameter of 70 μm or less.
When the size of these alloy particles, soft metal particles, and hard metal particles exceeds 70 μm, the strength tends to decrease.
Here, the circumscribed sphere diameter refers to the diameters a and b of the spheres B1 and B2 circumscribing the particles without protruding the particles P1 and P2 as illustrated in FIG. The average of circumscribed sphere diameters means the average value of circumscribed sphere diameters for each particle ((a + b) / 2 in the example of FIG. 6 showing two particles).

  It is preferable that the length of the dispersed phase in the direction perpendicular to the thickness direction is longer than the length in the thickness direction of the sliding layer. Thus, if the length in the direction perpendicular to the thickness direction of the sliding layer is long, the disperse phase made of the soft metal is likely to spread in the sliding direction of the counterpart material, and the non-seizure property is further improved. In the present invention, the following two methods are adopted in order to form the above sliding member.

  One method is a method in which hard metal particles are not included, and alloy particles composed of at least two metal components having a difference in hardness among two or more metal components to be phase-separated, and the alloy particles. Soft alloy particles made of a metal component that is not the hardest metal component among the at least two types of metal components are made to collide with a substrate by a high-speed working gas flow, and the alloy particles are placed on the substrate. And a soft metal particle are formed together to form a coating layer.

  Another method is a method in which hard metal particles are included, and alloy particles composed of at least two metal components having a difference in hardness among two or more metal components to be phase-separated, and the alloy particles. Soft metal particles comprising a metal component that is not the hardest metal component of the at least two types of metal components, and hard metal particles comprising a metal component that is not the softest metal component of the at least two types of metal components To the base material by a high-speed working gas flow to form a coating layer in which the alloy particles, the soft metal particles, and the hard metal particles are present together on the base material. Is.

  In this way, the alloy particles, soft metal particles, and hard metal particles are made to collide with the substrate by a high-speed working gas flow without melting, so the alloy particles and soft metal particles that collide with the substrate are formed. By selecting the size of the hard metal particles in advance, the alloy particles, soft metal particles, and hard metal particles when the coating layer is formed can be set to a desired size. When the particles collide with the substrate, the particles tend to be flattened and flattened. For this reason, the alloy particles, soft metal particles, and hard metal particles forming the coating layer tend to have a longer particle length in the direction perpendicular to the thickness direction than the particle length in the thickness direction of the coating layer. However, if the speed of the working gas flow is decreased, the particles on which the coating layer is formed do not become flat, and the original form is maintained. The alloy particles, soft metal particles, and hard metal particles are mixed well in advance and uniformly distributed, so that the alloy particles, soft metal particles, and hard metal particles when the coating layer is formed are uniformly dispersed in the coating layer. .

  From the above, in the alloy particles, a fine soft metal remains uniformly dispersed as a dispersed phase. In addition, the soft metal particles are dispersed in the coating layer as relatively large-sized particles, and exhibit foreign substance embeddability and conformability.

  In order to confirm the effect of the present invention, a sample having a coating layer formed on a substrate was prepared, and a seizure test and a fatigue test were performed on the sample. The prepared samples are Examples 1 to 21 and Comparative Examples 1 to 6 shown in Tables 1 and 2 below. The conditions of the seizure test and the fatigue test are shown in Table 3 and Table 4 below, respectively. The composition column of Table 1 shows the composition of the coating layer, and the manufacturing method column shows the method of manufacturing the coating layer. In this manufacturing method, “CS” is a method using a cold spray device. Moreover, the base material column of Table 2 shows the base material on which the multilayer is formed. In the base material column, “steel” means that a steel plate and “Al alloy” means an Al alloy layer with a backing metal layer, and “Cu alloy” means a Cu alloy layer with a backing metal layer.

  The cold spray device is a device for causing metal particles to collide with a substrate without melting, and includes a powder supply device, a gas heating device, and a gun including a tapered nozzle (Laval nozzle). The powder (metal particles) is supplied from the powder supply device to the gun, and the working gas is ejected from the gun at a high speed, so that the powder is vigorously collided with the substrate by the working gas flow. In this case, the working gas is heated by the gas heating device, so that the speed of the gas ejected from the gun can be increased. If the heating temperature by this heating device is too high, the metal particles are melted, so the temperature is set to 500 ° C or lower. Usually, it performed at 200-400 degreeC, and it carried out at 400 degreeC here.

  Moreover, normally, the working gas pressure was 0.4-4 Mpa, and it carried out here at 1-2 Mpa. The powder ejected from the gun vigorously collides with the base material and enters the base material, and the powder is laminated on the powder that has entered the base material to form a coating layer. Hereinafter, a method of forming a coating layer using this cold spray apparatus is referred to as a CS method.

Next, a method for producing the sample will be described.
<Example products 1 to 21>
* Example goods 1-3, 6-9, 12-16, 18
After fixing the degreased and washed steel plate to a jig and roughening the surface by blasting, the alloy particles, soft metal particles shown in the powder material column of Table 1, so as to have the composition shown in the composition column of Table 1, Hard metal particles were weighed and mixed evenly, and this was collided with a steel plate by a cold spray device to form a coating layer having a thickness of 1 mm. A bimetal provided with a coating layer on this steel plate (back metal layer) is pressed into a half bearing shape, and the steel product has a steel back metal thickness of 1.5 mm and a coating layer thickness of 0.2 to 0.3 mm. 3, 6-9, 12-16, 18 were obtained.

* Example products 4, 5, 10, 11
For example, an Al alloy consisting of 4% by mass of Zn, 1% by mass of Si, and the remaining Al is cast and rolled to produce an Al alloy plate. The Al alloy plate is rolled on the steel plate and both are pressed. And obtained bimetal. Then, this bimetal is pressed into a half bearing shape, and the one cut into a predetermined size is fixed to a jig, and is shown in the powder material column of Table 1 so that the composition shown in the composition column of Table 1 is obtained. The alloy particles, soft metal particles, and hard metal particles were weighed and mixed uniformly, and this was collided with the Al alloy layer by a cold spray device to form a coating layer having a thickness of 0.1 mm. In this case, the coating layer is formed by continuously moving the gun and the jig of the cold spray device so that the gun follows the inner surface of the half shape. Then, after forming the coating layer to a thickness of 0.1 mm, it was finished to finally become a coating layer having a thickness of 20 μm, and Example Products 4, 5, 10, and 11 were obtained.

* Example products 17, 19, 20, 21
For example, a sintering Cu alloy of Pb: 20% by mass, Sn: 3% by mass, and remaining Cu is uniformly dispersed on a steel plate having a thickness of 1.3 mm, and 800 to 920 in a reducing atmosphere. The first sintering was performed at a temperature of ° C. for about 15 minutes, and then roll rolling was performed. Furthermore, in order to increase the density, sintering and roll rolling were repeated as many times as necessary to produce a bimetal in which a Cu alloy layer was joined on the steel plate. Then, this bimetal is pressed into a half bearing shape, and the one cut into a predetermined size is fixed to a jig, and is shown in the powder material column of Table 1 so that the composition shown in the composition column of Table 1 is obtained. The alloy particles, soft metal particles, and hard metal particles were weighed and mixed uniformly, and this was collided with the Cu alloy layer by a cold spray apparatus to form a 0.1 mm thick coating layer. In this case, the coating layer is formed by continuously moving the gun and the jig of the cold spray device so that the gun follows the inner surface of the half shape. Then, the coating layer was formed to a thickness of 0.1 mm, and then finished so as to finally become a coating layer having a thickness of 20 μm, and Example Products 17, 19, 20, and 21 were obtained.

<Comparative product>
* Comparative product 1
After fixing the degreased and washed steel plate to a jig and roughening the surface by blasting, the alloy particles and soft metal particles shown in the powder material column of Table 1 are prepared so that the composition shown in the composition column of Table 1 is obtained. The mixture was weighed and mixed evenly, and this was sprayed onto the surface of the steel sheet by a thermal spraying device (high-speed flame spraying) to form a coating layer having a thickness of 1 mm to produce a bimetal. This bimetal was pressed into a half bearing shape and cut to a predetermined size to obtain a comparative product 1 having a steel back metal thickness of 1.5 mm and a coating layer thickness of 0.2 to 0.3 mm.

* Comparative example products 2, 3
An Al alloy plate having a composition shown in Table 1 was cast and rolled to produce an Al alloy plate. The Al alloy plate was superposed on the steel plate and roll-welded to form a bimetal. The bimetal was pressed into a half bearing shape and cut into a predetermined size to obtain comparative products 2 and 3.

* Comparative product 4
The bimetal used in the manufacture of the above-mentioned Examples 4, 5, 10, and 11 was pressed into a half bearing shape, and the product cut to a predetermined size was fixed to a jig, and the composition shown in the composition column of Table 1 So that the required amount of alloy particles shown in the powder material column of Table 1 is weighed and mixed evenly, and this is mixed into an Al alloy layer by a cold spray apparatus in the same manner as in the above-mentioned Examples 4, 5, 10, and 11. A 1 mm thick coating layer was formed by impact. Then, after forming a coating layer to a thickness of 0.1 mm, a final processing was performed to obtain a coating layer having a thickness of 20 μm.

* Comparative product 5
A required amount of a Cu alloy for sintering composed of alloy particles having the composition shown in the composition column of Table 1 is weighed and mixed evenly, and this is uniformly dispersed on a steel plate having a thickness of 1.3 mm. The first sintering was performed at a temperature of ˜920 ° C. for about 15 minutes, and then roll rolling was performed. Furthermore, in order to increase the density, sintering and roll rolling were repeated as many times as necessary to produce a bimetal in which a Cu alloy layer was joined on the steel plate. Then, this bimetal was pressed into a half bearing shape and cut into a predetermined dimension to obtain a comparative product 5.

* Comparative product 6
The bimetal used in the manufacture of the example products 17, 19, 20, and 21 was pressed into a half bearing shape and cut to a predetermined dimension, and the Ag alloy was plated on the Cu alloy layer to obtain a comparative example product 6 It was.

  About the coating layers of Examples 1 to 21 and Comparative Examples 1 to 6 manufactured as described above, the size of the alloy particles, the size of the dispersed phase of the soft metal in the alloy particles, the shape of the alloy particles, the soft particles The relationship between the size and shape, the size of the hard metal particles, the presence or absence of pores, the size of the dispersed phase of the soft metal in the alloy particles and the soft metal particles was examined and is shown in Table 2. The shapes of the alloy particles and the soft metal particles are shown by the magnitude relationship, where T is the length in the thickness direction of the coating layer and L is the length in the direction perpendicular to the thickness direction.

In addition, Table 2 shows the results of the seizure test and the fatigue test performed on Example Products 1 to 21 and Comparative Example Products 1 to 6. The results of this seizure test and fatigue test are considered.
The example products 1 to 21 are superior in both non-seizure properties and fatigue resistance compared to the comparative example products 1 to 6. Details will be described below.

(1) Examples 1 to 15 and Comparative Examples 1 to 4 have an Al alloy as a coating layer.
<Example products 1 to 3, 8, 9, 12 to 15 and comparative example products 1 and 2>
The example products 1 to 3, 8, 9, 12 to 15 and the comparative example products 1 and 2 have the same Sn content (20% by mass) in the coating layer.
Since the comparative example product 1 has a coating layer formed by thermal spraying, soft Sn is dispersed in a fine phase as shown in FIG. 5, but a structure having a large size cannot be seen. Therefore, the strength is high and the fatigue resistance is excellent, but the non-seizure property is insufficient. Since Comparative Example Product 2 has a coating layer formed by casting, a large size of soft Sn is present as shown in FIG. 4, but it has a structure in which a fine phase is not observed. For this reason, it is excellent in conformability and foreign substance embedding property, and hence non-seizure property, but has insufficient strength and lacks fatigue resistance.

  On the other hand, since Examples 1 to 3, 8, 9, 12 to 15 have a coating layer formed by the CS method, particles (soft metal) made of soft Sn having a large size as shown in FIG. Particle) 4 has a structure existing in the coating layer having Al as the matrix 6, and soft Sn is dispersed in a fine phase (dispersed phase) 8 in the alloy particle 10. Yes. For this reason, Example goods 1-3, 8, 9, 12-15 are excellent in conformity and foreign substance burying property, and by extension, non-seizure property, strength is sufficient, and fatigue resistance is also excellent. .

<Example products 4, 5, 10 and comparative product 3>
The example products 4, 5, and 10 and the comparative example product 3 have the same Sn content (60% by mass) in the coating layer. Since the coating layer of the comparative example product 3 is formed by casting, the non-seizure property is excellent as in the comparative example product 2, but the fatigue resistance is insufficient. On the other hand, Example goods 4, 5, and 10 are excellent in both non-seizure property and fatigue resistance.
In addition, when the particle | grains (hard metal particle) which consist of hard Si and Al are included, as shown with the particle | grains 11 which gave the hatching in FIG. 1, they exist in a coating layer.

<About Example Product 11>
In Example Product 11, the composition of the coating layer is the same as that of Example Products 4, 5, and 10. However, the size of the alloy particles is 70 μm or less in the example products 4, 5, and 10, whereas the size of the example product 11 exceeds 70 μm and is as large as 100 μm. For this reason, in the fatigue resistance, the example product 11 is lower than the example products 4, 5, and 10.

<Example products 1-3, 8, 9, 12-15 and comparative product 4>
Example product 1-3,8,9,12-15 and the comparative example product 4 have the same Sn content. And the coating layer of the comparative example product 4 is produced by CS method. However, since Comparative Example Product 4 uses only alloy particles and does not use soft metal particles, it has a structure with no large-sized Sn particles and is inferior in non-seizure properties. On the other hand, Example goods 1-3, 8, 9, 12-15 are superior to Comparative example goods 4 in both non-seizure property and fatigue resistance.

<About Example Products 1-3>
The shape of the alloy particles of Example Product 1 is L = T, but the shape of the alloy particles of Example Product 2 is L> T. And in the non-seizure property, the example product 2 is superior to the example product 1. In addition, the shape of the soft metal particles of Example Product 1 is L = T, but the shape of the soft metal particles of Example Product 3 is L> T. And in the non-seizure property, the example product 3 is superior to the example product 1. Thus, it is understood that the non-seizure property is improved when L> T for both the alloy particles and the soft metal particles.

<Example products 4 and 5>
In Example Product 4, the Sn phase in the alloy particles is larger than the Sn particles present alone as the soft metal particles. On the other hand, in Example Product 5, the Sn phase in the alloy particles is smaller than the Sn particles present alone as soft metal particles, and has a size of 4 μm or less, specifically 2 μm. The example product 5 is superior to the example product 4 in both non-seizure properties and fatigue resistance. As described above, it is understood that the non-seizure property and the wear resistance are improved when the dispersed phase of the soft metal in the alloy particles is smaller than the soft metal particles and is 4 μm or less.

<Examples 3, 5, 8-10, 14>
Example product 3 and example products 8, 9, 14 and Example product 5 and Example product 10 have the same Sn content. However, the example products 3 and 5 do not contain hard metal particles, whereas the example products 8 and 10 contain hard metal particles. And Example goods 8 and 10 containing hard metal particles have improved wear resistance, and are more excellent in fatigue resistance than Example goods 3 and 5 that do not contain hard metal particles. It was calculated from the difference in thickness of the coating layer before and after the fatigue test (see Table 5 below). By containing hard metal particles in this way, fatigue resistance and wear resistance are improved. The example products 9 and 14 containing Al ₂ O ₃ which is an oxide also have improved fatigue resistance and wear resistance.

<Example products 6, 7>
In Examples 6 and 7, the Sn content of the coating layer was as low as 5% by mass. However, the non-seizure property and the fatigue resistance are not inferior to those of other examples. Therefore, it is understood that if Sn (soft metal particles) is 5% by mass or more, a coating layer excellent in non-seizure property and wear resistance can be obtained.
In addition, the coating layer of Example Product 6 has no pores, but the coating layer of Example Product 7 has pores (the pores are mainly present between the particles, but are small and are not shown). (Omitted). The example product 7 having pores is more excellent in non-seizure than the example product 6 having no pores. Thus, the pores in the coating layer contribute to the improvement of non-seizure properties.
(2) The example products 16 to 19 and the comparative example product 5 have a Cu alloy as a coating layer.

<Comparison between Example Products 16-19 and Comparative Example Product 5>
The comparative product 5 has a coating layer formed by sintering. When the Pb-containing Cu alloy particles are sintered, Pb, which is a soft metal component having a low melting point, is eluted from the alloy particles and oozes out to the surface of the alloy particles. For this reason, there is no finely dispersed Pb phase in the sintered layer (coating layer).
On the other hand, Example products 16 and 18 have both soft metal particles similar to Comparative Example product 5 and a finely dispersed 5 μm Pb phase, thereby improving both non-seizure properties and fatigue resistance. is doing.
Moreover, Example goods 17 and 19 are the coating layers containing 70 mass% of Pb and Bi which exhibit a lubrication effect. Soft metal particles and fine dispersed phases of Pb and Bi have dramatically improved non-seizure properties while maintaining sufficient fatigue resistance.

(3) The example products 20 and 21 and the comparative example product 6 have Ag and an Ag-based alloy as a coating layer.
<Comparison between Example Products 20 and 21 and Comparative Example Product 6>
The comparative example product 6 is formed by performing Ag plating on the coating layer. For this reason, although it is excellent in fatigue resistance, it becomes a thing with low non-seizure property. On the other hand, the example products 20 and 21 are formed with a coating layer by the CS method and contain Pb as soft metal particles, so that they are excellent in fatigue resistance as well as non-seizure property. It will be a thing.

The present invention is not limited to the embodiments described above and shown in the drawings, and can be expanded or changed as follows.
The coating layer is not limited to those composed of two kinds of metal components that are phase-separated from each other, and may contain three or more kinds of metal components that are phase-separated from each other. It may be included.
When three or more kinds of metal components that are phase-separated from each other are included, the alloy particles may be composed of two kinds of metal components selected from these metal components that are phase-separated.
When there are three or more types of metal components constituting the alloy particles, the metal component constituting the soft metal particles may be a metal component having the second or later hardness among these three types of metal components.
The coating layer may contain, for example, carbide, nitride, or oxide particles such as Al ₂ O ₃ , SiC, Si ₃ N ₄ , WC, and Mo ₂ C. These are preferably 200 HV or more. The coating layer can contain a solid lubricant such as MoS ₂ or graphite. The Al ₂ O ₃ and MoS ₂ can be present in the coating layer in the same manner as the hard metal particles 11 shown by hatching in FIG.

The figure which shows the structure | tissue of the coating layer of this invention Cross section of sliding material Cross-sectional view of a sliding material different from FIG. Diagram showing the structure of the coating layer by casting Diagram showing the structure of the coating layer by thermal spraying Diagram showing the circumscribed sphere diameter of particles

Explanation of symbols

  In the drawings, 1 is a back metal layer, 2 is a bearing alloy layer, 3 is an overlay layer, 4 is soft metal particles, 6 is a matrix, 8 is a dispersed phase, and 10 is alloy particles.

Claims (16)

In a sliding material having a base material and a coating layer formed on the base material,
The coating layer includes two or more metal components that are phase-separated from each other,
Among the two or more kinds of metal components to be phase-separated, alloy particles comprising at least two kinds of metal components having a difference in hardness, and the hardest metal component among the at least two kinds of metal components constituting the alloy particles It has a structure with soft metal particles consisting of no metal components,
A sliding material, wherein the alloy particles have a dispersed phase composed of a metal component that is not the hardest metal component dispersed in the alloy particles.   The sliding material according to claim 1, wherein the alloy particles have a particle length in a direction perpendicular to the thickness direction longer than a particle length in the thickness direction of the coating layer.   The sliding material according to claim 1 or 2, wherein the soft metal particles have a particle length in a direction perpendicular to the thickness direction longer than a particle length in the thickness direction of the coating layer.   The sliding material according to claim 1, wherein the dispersed phase is smaller than the soft metal particles.   The sliding material according to claim 1, wherein the dispersed phase has a size of 4 μm or less.   The sliding material according to claim 1, wherein pores are present in the coating layer.   The sliding material according to claim 1, wherein the pores are smaller than the dispersed phase.   The alloy particle, the soft metal particle, and a hard metal particle composed of a metal component that is not the softest metal component among at least two types of metal components constituting the alloy particle are present together. The sliding material according to claim 1, wherein:   The sliding material according to claim 1, wherein the soft metal particles are uniformly distributed in the coating layer.   The sliding material according to claim 8, wherein the hard metal particles are uniformly distributed in the coating layer.   11. The sliding material according to claim 1, wherein the alloy particles have an average circumscribed sphere diameter of 70 [mu] m or less.   The sliding material according to any one of claims 1 to 11, wherein the soft metal particles have an average circumscribed sphere diameter of 70 µm or less.   The sliding material according to claim 8, wherein the hard metal particles have an average circumscribed sphere diameter of 70 μm or less.   14. The sliding according to claim 1, wherein the dispersed phase has a length in a direction perpendicular to the thickness direction longer than a length in a thickness direction of the sliding layer. material. In the method of manufacturing the sliding material according to claim 1,
Alloy particles composed of at least two metal components having a difference in hardness among two or more metal components to be phase-separated, and not the hardest metal component among the at least two metal components constituting the alloy particles A soft metal particle made of a metal component is caused to collide with a base material by a high-speed working gas flow to form a coating layer in which the alloy particles and the soft metal particles are both present on the base material. A method for producing a sliding material. In the method of manufacturing the sliding material according to claim 8,
Alloy particles composed of at least two metal components having a difference in hardness among two or more metal components to be phase-separated, and not the hardest metal component among the at least two metal components constituting the alloy particles The soft metal particles made of a metal component and the hard metal particles made of a metal component that is not the softest metal component among the at least two kinds of metal components are caused to collide with the substrate by a high-speed working gas flow, A method for producing a sliding material, comprising: forming a coating layer in which the alloy particles, the soft metal particles, and the hard metal particles are present together on a base material.

Images