WO2004092602A1

WO2004092602A1 - Sliding member

Info

Publication number: WO2004092602A1
Application number: PCT/JP2004/005512
Authority: WO
Inventors: Satoshi Takayanagi; Masahito Fujita; Takayuki Shibayama
Original assignee: Daido Metal Company Ltd.
Priority date: 2003-04-17
Filing date: 2004-04-16
Publication date: 2004-10-28
Also published as: JPWO2004092602A1; JP4589229B2; DE112004000651T5; GB0521504D0; GB2415753A; GB2415753B; DE112004000651B4

Abstract

A sliding member which has a substrate and a sliding layer (overlay), wherein the overlay (sliding layer) (4) comprises a base material of a metal selected from among Sn, Pb, Bi, In and Al or an alloy based on the metal and an amorphous carbon as an additive. The overlay (4) is formed by sputtering. Sn, Pb, Bi or In is excellent in non-seizure property due to its low adhesion to a mating material such as Fe. An amorphous carbon improve wear resistance and fatigue resistance due to its high hardness and also improve non-seizure property due to its low friction coefficient. Further, by the addition of an amorphous carbon, the above base material having finer crystal grains is formed, which results in the enhancement of the mechanical strength and further improvement of the wear resistance and fatigue resistance of the overlay (sliding layer).

Description

Description Slides Technical field

The present invention relates to a sliding member having a sliding layer on a substrate. Background art

2. Description of the Related Art Conventionally, a sliding member, for example, a plain bearing for an engine in an automobile has a configuration in which a sliding layer (overlay) is provided on a base material.

The use of a Sn-based coating as the sliding layer is widely known as disclosed in Japanese Patent Application Laid-Open No. Sho 53-14614. It is well known that an overlay coating is formed using a soft metal base such as a Pb-based coating in addition to an Sn-based coating.

In addition to Sn and Pb, soft metals such as In and Bi have very low anti-seizure properties due to their low adhesion to mating materials such as Fe, so many conventional sliding members have been used. Has been used for sliding layers.

However, these metals are poor in fatigue resistance because of their softness, and often cannot be used in high surface pressure engines.

In order to solve this problem, for example, in Japanese Patent Application Laid-Open No. 2000-21049,

It is proposed to form an overlay coating by adding a large amount of metal, such as Cu, that can improve the hardness and mechanical strength of the Sn-based substrate to the Sn-based substrate. Have been. However, Sn and Cu tend to form hard and brittle compounds, and the heat generated during operation of the engine tends to promote the growth of such compounds. Such a hard and brittle compound easily damages the mating material and reduces non-seizure properties. Furthermore, there is a problem that a compound that has grown large tends to fall off, and it is easy for fatigue fracture to occur from the fallout portion, resulting in a decrease in fatigue resistance. Abrasion resistance of the sliding layer を In order to improve the fatigue resistance, hard particles (for example, S i C, S i ₃ N ₄ ) were sometimes added by the composite plating technique. However, the hard particles to be added by the multiple plating technique have a large particle size from 0.1 m to several / zm. The distribution of hard particles often fluctuated in the overlay coating. In such a sliding layer, large hard particles or large hard particles are likely to damage the mating material, and the non-seizure property is reduced.

On the other hand, sliding bearings used in diesel engines that are subject to high loads require fatigue resistance. To meet this demand, an A1 base coating has been often used as a sliding layer for sliding bearings for diesel engines. Specifically, the A 1 -based coating is made of an Al—Sn alloy, with A 1 supporting the load, and soft Sn serving as conformability and non-seizure property.

Therefore, when the Sn content is increased in the A1-Sn alloy sliding layer, the non-seizure property can be improved. However, when the soft Sn increases, the hardness of the sliding layer decreases, which causes a problem that fatigue resistance decreases. Under such circumstances, in the conventional A1-Sn alloy sliding layer, Sn is usually added up to a limit of 20% by mass, but it is not satisfactory in non-seizure properties. .

The present invention has been made in view of the circumstances described above, and its purpose is to provide Sn,

When the sliding layer is made of any one of Pb, Bi, In, and A1 or an alloy based on the metal, fatigue resistance can be improved, and In particular, when the sliding layer is made of an A1-Sn alloy, a sliding member provided with a sliding layer capable of improving non-seizure properties without impairing fatigue resistance is provided. It is in. Disclosure of the invention The present invention provides a sliding layer on a substrate, wherein the sliding layer is made of any one of Sn, Pb, Bi, In, and A1 or an alloy based on the metal. The substrate is characterized by adding amorphous carbon to the substrate.

The sliding layer can be formed by a dry plating method such as a sputtering method, an ion plating method, and a CVD method.

Of the metals used for the base material of the sliding layer, Sn, Pb, Bi, and In, excluding A1, are extremely non-seizure due to their low adhesion to mating materials such as Fe. Are better.

When A1 is used for the base material of the sliding layer, the non-seizure property can be improved by using an alloy with another soft metal, for example, Sn. Even if the amount of Sn added is increased, A1 and Sn become finer due to the addition of amorphous carbon, resulting in high strength. For this reason, a defect such as a decrease in fatigue resistance does not occur, and a sliding layer excellent in both fatigue resistance and non-seizure properties can be obtained. Amorphous carbon is high in hardness, so it increases mechanical strength and contributes to abrasion resistance and fatigue resistance. Also, the low coefficient of friction contributes to the improvement of non-seizure properties. Moreover, by adding amorphous carbon, the crystallites of the base material of the sliding layer are refined. With this, the mechanical strength of the sliding layer increases, and the wear resistance and fatigue resistance can be further improved.

Here, the crystallite is a unit serving as a basis of particles in the sliding layer and a base containing the particles. Refinement of crystallites is, of course, the refinement of the substrate. In addition, as described later, crystallites can be confirmed by X-ray diffraction analysis, and particles can be confirmed by microscopic observation with a scanning electron microscope.

As the amorphous carbon, diamond-like carbon (hereinafter, referred to as DLC) is particularly preferable. Note that DLC in the present specification includes not only an amorphous material but also a material having fine crystals.

In this case, it is preferable that the crystallite diameter of the substrate measured by X-ray diffraction analysis is 100 nm or less. By making the crystal of the base material of the sliding layer finer to this extent, the mechanical strength is increased as described above, and the wear resistance and fatigue resistance can be further improved. Can be.

Any one or more of Sn, Pb, Bi, Al, In, Cu, Sb, Ag, and Cd metals can be added to the base of the sliding layer. In this case, Sn, Pb, Bi, In, and Al are metals that can also serve as a base material, and have a function of improving non-seizure, conformability, and corrosion resistance. In addition, Cu, Sb, Ag, and Cd have the function of increasing the mechanical strength and hardness of the sliding layer. .

When the additive metal is at least one of Sn, Pb, Bi, In, and A1, the content of each additive metal is 20% by mass or less, and the total of these additive metals is Is preferably 30% by mass or less. However, when the base material is Sn and Al, the cases where the added metals are Al and Sn are excluded. If the content of each of these added metals exceeds 20% by mass or the total content of them exceeds 30% by mass, the melting point of the sliding layer is greatly reduced, and the non-seizure property tends to be reduced. There is.

When the additional metal is at least one of Cu, Sb, Ag, and Cd, the content of each additional metal is 5% by mass or less, and the total content of these additional metals is Is preferably 10% by mass or less. These added metals tend to form hard and brittle compounds with the base material of the sliding layer. Therefore, if the content of each of these added metals exceeds 5% by mass, or if the total content of them exceeds 10% by mass, the compound becomes large and easily falls off. Fatigue fracture and wear progress, and fatigue resistance and wear resistance tend to decrease.

When A1 is used for the base material of the sliding layer, it is preferable to use an alloy with Sn, and the content thereof is 20 to 80% by mass for 1 and 20 to 80% by mass for Sn. 1. Add amorphous carbon to the Sn alloy base. In this A 1 -Sn alloy, even if the content of Sn is increased, the addition of amorphous carbon makes the Al and Sn crystals finer and increases the mechanical strength, resulting in lower wear resistance. It is possible to provide a sliding layer that is excellent in wear resistance and non-seizure properties without causing any danger.

The alloys of A1 and Sn that constitute the sliding layer include Si, Cu, Sb, In, and Ag. Any one or more of these metals can be added. In can improve non-seizure, conformability, and corrosion resistance. Cu, Sb, and Ag increase the mechanical strength and hardness of the sliding layer. Since Si is a hard element, it increases the hardness of the sliding layer and improves fatigue resistance. In addition, Si functions as a hard material and has a function of removing metal adhered to a mating material, thereby improving non-seizure properties. Preferably, these Si, Cu, Sb, In, and Ag alone are 5% by mass or less, and the total content of the added metals is 10% by mass or less. .

If the content of each of In and Ag exceeds 5% by mass or the total content thereof exceeds 10% by mass, the melting point of the sliding layer is greatly reduced, and the non-seizure property is reduced. Tend. Cu, Sb, and Ag form hard and brittle compounds with A1 and Sn, and the content of each of the added metals exceeds 5% by mass, or the total content thereof is 1%. If the content exceeds 0% by mass, the compound becomes large, so that it tends to fall off, and fatigue and wear tend to progress. In addition, Si hardly forms a compound with A1 or Sn, and when Si is contained in a large amount, Si tends to easily fall off the sliding layer.

The Al-Sn alloy is refined by adding amorphous carbon. The degree of the fineness is preferably 1 m or less in terms of the particle diameter of A1 or Sn. When the particle diameter is 1 zm or less, the effects of improving the fatigue resistance and the anti-seizure property are further improved.

More preferably, the particle size is 0.05 or less. The finer the crystal becomes, the smaller the particle diameter becomes to 0.05 / m or less, the more excellent the fatigue resistance becomes.

Also, the crystallite diameter can be 30 nm. When the crystallite diameter is so fine, more excellent fatigue resistance can be obtained.

Here, the mechanism of the refinement of crystallites by the addition of amorphous carbon will be described. Amorphous carbon hinders the growth of crystallites and crystallites are refined.

When the substrate is a single metal such as Sn, The refinement can be confirmed by X-ray diffraction analysis, but the difference cannot be confirmed by the presence or absence of amorphous carbon in the cross-sectional structure observation with a scanning electron microscope.

Addition of amorphous carbon to A 1—Sn alloy to form an overlay Film Amorphous carbon also hinders growth of A 1 and Sn crystallites, and A 1 and Sn crystallites become finer Is done. This can be confirmed by X-ray diffraction analysis as described above. In addition, when the cross-sectional structure is observed when amorphous carbon is not added, A 1 and Sn can be observed as their respective phases. If there is a difference in the content of AIS n, the smaller is observed as particles. it can. However, when amorphous carbon is added, the crystallites of A1 and Sn become finer, and it becomes extremely difficult to capture the particles of A1 or Sn by cross-sectional structure observation with a scanning electron microscope.

In a sliding layer made of any one of the above-mentioned metals of Sn, Pb, Bi, In, and A1 or an alloy based on the metal, and adding amorphous carbon to the substrate. The content of amorphous carbon is preferably 0.1 to 8% by mass. When the content of the amorphous carbon is 0.1% by mass or more, the crystal of the substrate is sufficiently refined, and the hardness increases. Further, when the content is 8% by mass or less, the hardness is appropriately high, and the non-seizure property can be maintained without impairing the foreign matter embedding property.

Further, the thickness of the sliding layer is preferably 30 in or less. When it is 30 m or less, it is effective in reducing the internal stress of the sliding layer, and is preferable in terms of fatigue resistance. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of a sliding bearing according to an embodiment of the present invention.

Figure 2 is a schematic cross-sectional view showing the crystallites in the overlay

Fig. 3 shows the composition of the overlay used in the experiment to show the effect of the present invention and the experimental result. Fig. 4 shows the condition of the fatigue test.

Figure 5 is a diagram for explaining the half width Figure 6 shows the measurement data of X-ray diffraction analysis of Comparative Example 1.

Figure Ί shows the measurement data of the X-ray diffraction analysis of Example 2.

FIG. 8 is a diagram showing an overlay configuration and an experimental result used in an experiment showing the effect of the present invention in another embodiment.

Figure 9 shows the seizure test conditions

FIG. 10 is a schematic diagram of a structure observed by a scanning electron microscope of Example 12.

Fig. 11 is a schematic diagram of the structure observation by scanning electron microscope of Comparative Example 3 ... Best Mode for Carrying Out the Invention

The present invention will be described in more detail with reference to the accompanying drawings. 1 to 7 show one embodiment of the present invention. First, FIG. 1 schematically shows a cross section of a sliding bearing as a sliding member. The sliding bearing 1 includes a back metal 2 made of steel, a bearing alloy layer 3 provided on the upper surface of the back metal 2 in the drawing, and a sliding layer provided on the upper surface of the bearing alloy layer 3 in the drawing. It has a three-layer structure with the overlay 4. In this case, the back metal 2 and the bearing alloy layer 3 constitute the base material 5, and the overlay 4 is provided on the base material 5. As the bearing alloy layer 3, an aluminum alloy or a copper alloy is generally used. The overlay 4 is formed so as to have a thickness of 3 Om or less.

FIG. 3 shows the configurations of Examples 1 to 10 of the present invention and Comparative Example 1 for the overlay 4. In FIG. 3, in Examples 1 to 3 and 7, Sn of Sn, Pb, Bi, In, and Al was used as the base of the overlay 4, and an amorphous force (C) was used. ) Is added. In Examples 4 and 8, a Sn-based Sn—Cu alloy is used as a base material, and amorphous carbon (C) is added to the Sn—Cu alloy. In Examples 5 and 9, a Pb-based Pb-Sn-Cu alloy and a Pb-Sn-In alloy were used, respectively, and amorphous carbon (C) was added to these alloys. In Examples 6 and 10, Bi and Al were used for the base material, respectively, and amorphous carbon (C) was added thereto. In Comparative Example 1, Sn was used alone, and amorphous carbon (C) was not added.

Here, Examples 1 to 10 of the present invention and Comparative Example 1 were formed using a magneto opening / closing device.

Next, a method for forming the overlay 4 of the second embodiment among the first to tenth embodiments will be specifically described. The film forming methods of Examples 1, 3 to 10 and Comparative Example 1 are the same as the film forming method of Example 2. First, the base material 5 is set in the base material mounting portion of the above-mentioned apparatus, and each target of Sn, which is a raw material of the base material of the overlay, and Graphite (Gr), which is a raw material of the amorphous carbon, is placed in a predetermined position. Attach to the target attachment section of the above device at a ratio

Next, in Chiyanba of the device up to 1.0 x 10- ⁶ T shed rr, perform vacuuming, then supplies the A r gas into the chamber in one, the pressure in the chamber one 2. 0 X 1 0 - ³ Adjust so that it becomes Torr.

Then, in order to perform Ar cleaning on the surface of the substrate 5, a bias voltage of 1000 V is applied, Ar plasma is generated between the substrate 5 and the target, and reverse sputtering is performed for 15 minutes.

Next, a voltage is applied so that a current of 2 to 5 A flows to the Sn target and a current of 4 to 7 A flows to the Gr target.

Then, from the Sn target, the Sn atoms are sputtered by the collision of Ar ions, and a film is formed on the surface of the substrate 5. In addition, carbon atoms are sputtered from the Gr target by the collision of Ar ions, and are added as amorphous carbon during the overlay. As a result, an overlay 4 in which amorphous carbon is uniformly dispersed is formed in the Sn base.

In the above-mentioned manufacturing method, methane (CH ₄ ) gas is supplied into the chamber without using a Gr target, thereby adding DLC, which is amorphous carbon containing hydrogen atoms, to the Sn base. be able to. In this case, after reverse sputtering, the gas flowing into the device is changed to Ar gas and methane gas, The flow ratio of methane gas to the amount is set to 20 to 50%.

Then, Sn atoms are sputtered by Ar ions from the Sn target, and a film is formed on the surface of the substrate 5. The methane gas is decomposed in the plasma and added to the Sn substrate as DLC consisting of C atoms and H atoms.

FIG. 2 schematically shows a cross-sectional view of the overlay of Example 2 formed as described above. In FIG. 2, reference numeral 6 denotes a crystallite of Sn, and reference numeral 8 denotes DLC. In FIG. 2, it can be seen that the crystallite diameter of the Sn substrate is 100 nm or less.

Next, a method for measuring the crystallite size (crystallite diameter) of the overlay will be described. Here, X-ray diffraction analysis was performed using an X-ray diffraction analyzer to determine the half-value width of the peak corresponding to a certain crystal plane, which was applied to the following Scherrer equation (Equation (1)) to obtain the crystallite size. Ask for size. As shown in FIG. 5, the half width is a range of 2% where the intensity is higher than 1 p / 2 when the maximum intensity of the peak is lp.

B = K λ / t-cos 0… (1)

B: Diffraction line spread due to crystallite size

K: Form factor

λ: X-ray wavelength used for measurement

：: crystallite size

Θ: Bragg angle of diffraction line

When obtaining the half width, the obtained peak is separated into K or 1 peak and Κα2 peak.

FIG. 6 corresponds to Comparative Example 1, and is an example in which the half-value width is obtained from the peak of, for example, the (3 1 2) plane of the overlay of S η alone, and the crystallite size is obtained. The half width measured and calculated from the Κα1 peak obtained from the (3 12) plane peak was 0.070 °. As a result, the crystallite size was 150 nm.

On the other hand, Fig. 7 shows a sample corresponding to Example 2 (an example in which 2% by mass of amorphous carbon was added to the Sn base material), in which the peak of the (312) plane of the overlay was observed. This is an example in which the half-width is determined from the above to determine the crystallite size. The half width measured and calculated from the K 1 peak obtained from the (3 12) plane peak was 0.307 °. As a result, the crystallite size was 34 nm.

In addition, the same measurement was performed on Examples 1 and 3 to 10 other than Example 2. As a result, the diameter of the crystallites of the base material was 1.0 O nm or less in each case. The diameter of crystallite 1 was 3 O nm or less. „.

In order to confirm the effect of the present invention, a fatigue test was performed on Examples 1 to 10 and Comparative Example 1 described above. Figure 4 shows the test conditions. In this case, in the fatigue test, the surface pressure was increased in increments of 5 MPa, and the maximum surface pressure that did not cause fatigue was determined. The test results are shown in Figure 3 above. FIG. 3 also shows the measurement results of the hardness of the overlay (sliding layer). .

Consider the test results in Figure 3. First, Comparative Example 1 is a case where the bare is Sn alone. In this case, it can be seen that the Vickers hardness is low and the fatigue resistance is poor. On the other hand, in Examples 1 to 10, the Beakers hardness was hardened to 20 or more in all cases, and it was found that the fatigue resistance was superior to that of Comparative Example 1.

Next, Examples 1 to 10 will be examined in more detail. In Examples 1 to 3 and 7, not only are they excellent in fatigue resistance, but Example 1 is relatively low in hardness and particularly excellent in foreign matter embedding property, and Examples 2 and 3 are non-fatigue maximum. The surface pressure is 12 OMPa or more, and the fatigue resistance is particularly excellent. Based on these results, the content of the amorphous carbon (C) is preferably from 0.1 to 8.0% by mass, more preferably from 0.5 to 6% by mass.

Example 2 and Example 4 will be compared. Although the content of the amorphous carbon (C) is the same, in Example 4, Cu was added, and the fatigue resistance was higher than in Example 2 in which Cu was not added. This is considered to be because the addition of Cu increases the mechanical strength and hardness of the sliding layer and increases the fatigue resistance. Example 4 and Example 8 will be compared. The content of amorphous carbon (C) is the same, but in Example 4, the content of Cu was 2% by mass, and the content of Cu exceeded 5% by mass from Example 8 Also the fatigue resistance is improved.

In the ninth embodiment, Pb is used as a base material, and amorphous silicon, Sn. And In are added thereto. In Example 10, A1 was used as a base material, and amorphous carbon was added thereto. Also in this case, it is excellent in fatigue resistance as in the other examples. From the above results, in Examples 1 to 10 of the present invention, any one of Sn, .Pb, Bi, In, and A1 or an alloy based on the metal was overlayed. It can be seen that a sliding member having particularly excellent fatigue resistance can be provided by using the base material.

8 to 11 show another embodiment of the present invention. This embodiment is directed to a case where the base material of the single valley 4 shown in FIG. 1 is an A1-Sn alloy. FIG. 8 shows the compositions of Examples 11 to 22 and Comparative Examples 2 and 3 of the present invention. In FIG. 8, Examples 11 to 16 are obtained by adding amorphous carbon to an A1-Sn alloy based on A1, and Examples 17 to 20 are obtained based on Sn. A 1—Sn alloy with amorphous carbon added. Further, Example 21 is a sample in which Si and amorphous carbon are added to an A 1 -Sn alloy based on A 1, and Example 22 is an A 1 -S n alloy based on A 1. It is made by adding Cu and amorphous carbon to an alloy.

Further, in Comparative Examples 2 and 3, the base material was an A1-Sn alloy based on A1 and no amorphous carbon was added.

Film formation of the overlay 4 of Examples 11 to 22 and Comparative Examples 2 and 3 was performed in the same manner as the film formation of Example 2 described above. In this case, at the time of sputtering, a single metal of Sn and A1 or an A1-Sn alloy preliminarily alloyed by a structure can be used as a target.

After the film formation, the sections of the overlays of Example 12 and Comparative Example 3 were observed for their structures with a scanning electron microscope. The magnification of the scanning electron microscope used was 300 ×. It is.

FIG. 10 is a schematic diagram of the cross section of the overlay of Example 12 observed with a scanning electron microscope, and FIG. 11 is a schematic diagram of the cross section of the overlay of Comparative Example 3 observed with a scanning electron microscope. It is. .

As is clear from FIG. 11, in Comparative Example 3 in which amorphous carbon was not added,

The particles of Sn in A1 can be captured by a scanning electron microscope, and the particles of Sn have a small particle size, but are generally larger than 1 Atm. On the other hand, in Example 12 in which the amorphous carpon was added, as shown in FIG. 1.0, the particles of A 1 and Sn were not visible. The reason for this is that the particles in [81] [3] 1 were too small to be detected by the scanning electron microscope used, and similar results were obtained if no particles were present in the overlay. Incidentally, when the crystallite size of the overlay of the sample of Example 12 was measured by X-ray diffraction analysis, the crystallite size of A1 was 18 nm, and the crystallite size of Sn was Ί5 nm. Met. Fatigue tests and seizure tests were performed on Examples 11 to 22 and Comparative Examples 2 and 3, and the results are shown in FIG. The fatigue test conditions are the same as in FIG. Fig. 9 shows the seizure test conditions. In this case, in the seizure test, the surface pressure was increased by 5 Pa after the running-in operation, and the maximum surface pressure without seizure was determined. FIG. 8 also shows the measurement results of the Beakers hardness of the overlay.

In Fig. 8, the test results were examined.Comparative Examples 2 and 3 where no amorphous carbon was added, Examples 11 and 22 where amorphous carbon was added showed that the metal constituting the overlay was Since the crystallites become finer, the hardness becomes higher and the fatigue resistance is improved.

When the amorphous carbon is DLC, DLC is a substance with a small coefficient of friction.As can be understood from the comparison between Example 11 and Comparative Example 2 where the Sn content is the same, if DLC is contained, non-seizure occurs. The performance is improved.

On the other hand, as can be understood from Comparative Examples 2 and 3, when the Sn content of the Al—Sn alloy is increased, the hardness of the overlay is reduced and the fatigue resistance is reduced. But However, as can be understood from a comparison between Example 12 and Comparative Example 3, when the amorphous carbon was added, the hardness of the overlay was increased due to the refinement of crystallites, so the Sn content was reduced. High fatigue resistance even when increased.

As is clear from Examples 12, 14, and 16, the anti-seizure property is improved as the added amount of Sn is increased. The following two reasons are considered for the improvement of non-seizure property with the increase of Sn content.

Lubricating oil plays a very important role in sliding. Lubricating oil exists between the two sliding members, and seizure does not occur when an oil film is formed. For this reason, the overlay of the slide bearing is preferably made of a material that can easily form an oil film. The wettability with lubricating oil, which is a parameter that indicates the ease with which an oil film is formed, is higher for Sn than for A1. For this reason, the non-seizure property increases as the overlay contains more Sn. This is the first reason.

The second reason is as follows. If oil runs out between two sliding members, frictional heat is generated. When the oil film starts to partially break, frictional heat is generated only locally, but when the area ratio at which the oil film breaks increases, the frictional heat increases, and an adhesion reaction occurs between the two members. And burn. However, if a low melting point metal, Sn, is present in the overlay, it will locally melt when the oil slick begins to partially break. Since the latent heat at that time absorbs the frictional heat, the frictional heat is not accumulated, and as a result, seizure is prevented.

When the Sn content is increased in this manner, the non-seizure property is improved. In addition, when amorphous carbon is added, fatigue resistance is improved due to the refinement of crystallites, so that non-seizure properties can be improved while improving fatigue resistance.

The improvement of the fatigue resistance and anti-seizure property by adding the Sn content when amorphous carbon is added is not limited to the Al-Sn alloy based on A1, but is shown in Examples 17 to 20. As can be seen, the 8 1-31 1 alloy based on 3] is also improved in non-seizure properties while maintaining excellent fatigue resistance by increasing the Sn content in the same manner. be able to. In addition, as can be understood from the comparison between Examples 21 and 22 and Example 14, fatigue resistance can be improved by including Si and Cu, and in particular, Si is included. When it is included, the non-seizure property can be improved at the same time.

Note that the present invention is not limited to the above-described embodiment, and for example, the following modifications are possible.

In the plain bearing 1, the overlay 4 is provided directly on the upper surface of the bearing alloy layer 3.However, an intermediate layer such as Ni--Cr or Ti is provided on the upper surface of the bearing alloy layer 3, and this intermediate layer is formed. The overlay 4 may be provided on the upper surface. Further, the overlay 4 may be provided directly on the upper surface of the back metal 2. Further, a conformable layer of a soft metal such as pure Sn or a resin such as PAI may be provided on the upper surface of the overlay 4. The base of the overlay 4 may be made of In. Further, the added metal for increasing the mechanical strength and hardness of the overlay 4 is not limited to 11, but may be any one of Sb, Ag, and Cd, or two or more of them may be used. . Industrial applicability

As described above, the sliding member according to the present invention is useful as a slide bearing in which a sliding layer having a thickness of 30 zm or less called an overlay is formed on a bearing alloy.

Claims

The scope of the claims

1. A sliding layer is provided on a base material, and the sliding layer is made of any one of Sn, Pb, Bi, In, and A.1 or an alloy based on the metal, and A sliding member characterized by adding amorphous carbon to the substrate.

2. The sliding member according to claim 1,

The base material has a crystallite diameter of 100 nm or less.

3. The sliding member according to claim 1,

It is characterized in that at least one metal selected from the group consisting of Sn, Pb, Bi, In, Al, Cu, Sb, Ag and Cd is added to the substrate.

4. In the sliding member according to claim 2,

5. The sliding member according to claim 3,

When the additive metal is at least one of Sn, Pb, Bi, In, and A1, the content of each additive metal is 20% by mass or less, and the total of these additive metals is Is not more than 30% by mass.

6. The sliding member according to claim 4,

7. The sliding member according to any one of claims 3 to 6,

When the additive metal is at least one of Cu, Sb, Ag, and Cd, the content of each additive metal is 5% by mass or less, and the total content of these additive metals. Is not more than 10% by mass.

8. The sliding member according to claim 1,

The base material of the sliding layer is as follows: 81 is 20 to 80% by mass and Sn is 20 to 80% by mass. An alloy of A1 and Sn, wherein amorphous carbon is added to the base material of the A1-Sn alloy.

9. The sliding member according to claim 8,

The alloy of A1 and Sn constituting the base is added with at least one metal selected from the group consisting of Si, Cu, Sb, In, and Ag.

10. The sliding member according to claim 9,

The content of Si, Cu, Sb, In, and Ag is characterized by being 5 mass% or less alone and 10 mass% or less in total.

1 1. The sliding member according to any one of claims 8 to 10,

The particle diameter of A 1 or Sn in the substrate is 1 m or less.

12.The sliding member according to any one of claims 8 to 10, wherein

The particle diameter of A 1 or Sn in the substrate is 0.05 m or less.

13. The sliding member according to claims 8 to 10,

The base material has a crystallite diameter of 30 nm or less.

14. The sliding member according to claim 11,

The base material has a crystallite diameter of 30 nm or less.

15. The sliding member according to claim 12,

The base material has a crystallite diameter of 30 nm or less.

16. In the sliding member according to any one of claims 1 to 6, and 8 to 10,

The content of the amorphous carbon is 0.1 to 8% by mass.

17. The sliding member according to claim 7,

The content of the amorphous carbon is 0.1 to 8% by mass.

18. The sliding member according to claim 11, The content of the amorphous carbon is 0.1 to 8% by mass.

19. The sliding member according to claim 12,

The content of the amorphous carbon is 0.1 to 8% by mass.

20. The sliding member according to claim 13,

The content of the amorphous carbon is from 8 to 8% by mass.

21. The sliding member according to claim 14,

The content of the amorphous carbon is 0.1 to 8% by mass.

22. The sliding member according to claim 15,

The content of the amorphous carbon is 0.1 to 8% by mass.

'23. The sliding member according to any one of claims 1 to 6 and 8 to 10,

The thickness of the sliding layer is 3 Ozm or less.

24. The sliding member according to claim 7,

The sliding layer has a thickness of 30 / m or less.

25. The sliding member according to claim 11,

The thickness of the sliding layer is 30 m or less.

26. The sliding member according to claim 12,

The thickness of the sliding layer is 30 m or less.

27. The sliding member according to claim 13,

The thickness of the sliding layer is 30 m or less.

28. The sliding member according to claim 14,

The sliding layer has a thickness of 30 / m or less.

29. The sliding member according to claim 15,

The sliding layer has a thickness of 30 / m or less.

30. The sliding member according to claim 16,

The thickness of the sliding layer is 3 Om or less.

3 1. The sliding member according to claim 17,

The thickness of the sliding layer is 3 Ozm or less. .

3.2. The sliding member according to claim 18,

The sliding layer has a thickness of 30 μm or less.

33. The sliding member according to claim 19,

The sliding layer has a thickness of 30 zm or less.

34. The sliding member according to claim 20,

The thickness of the sliding layer is 30 m or less.

35. The sliding member according to claim 21,

The sliding layer has a thickness of 30 im or less.

36. The sliding member according to claim 22,

The sliding layer has a thickness of 30 zm or less.