JPH0277540A - Al-sn bearing alloy - Google Patents

Abstract

PURPOSE:To obtain the title bearing alloy having excellent lubricity and mechanical characteristics at high oil temp. in which the shape of Si grains precipitated in an Al matrix is regulated to the roundish one by adding specific amounts of Sb to an Al-Sn bearing alloy contg. Si. CONSTITUTION:As a lightweight Al-Sn bearing alloy, >0.01 to <0.1% Sb is added to a bearing alloy contg., by weight, 7 to 20% Sn, 0.1 to 5% Pb, 1 to 10% Si, total 0.3 to 3.0% of one or more kinds among the elements for the strengthening of an Al matrix such as Cu, Mg and Zn and the balance Al. The shape of hard Si grains 2 precipitated in an Al matrix 1 of the bearing alloy is converted into nearly the spherical one or the roundish one in the tip by the addition of Sb and Sn-Pb alloy grains 3 are precipitated adjacently to the Si grains 2 to form a lubricating oil film between projecting Si and sliding mating members, by which the Al-Sn bearing alloy having excellent seizure resistance, fatigue resistance and wear resistance can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an At-3n bearing alloy, and more specifically, 31 particles are precipitated in a matrix in a spherical or nearly spherical shape, and moreover, it is suitable for high-speed and high-load operation. In particular, the AJ-3n series bearing alloy has excellent fatigue resistance, seizure resistance, and wear resistance under high oil temperatures.

Conventional technology Recently, automobile engines have become smaller, more fuel efficient, and have higher output.As a result, the load on the bearings has increased, the temperature of the lubricating oil has also increased, and the operating conditions for the bearings have changed. It is becoming more and more severe. From this point of view, in conventional multi-component systems, Al systems, etc., a surface layer of Pb-3n system, etc. is formed on the surface of the bearing base metal by overlay plating, etc., but in bearings with this structure, the lubricating surface is They suffer from fatigue and seizure phenomena due to high temperatures, and are no longer able to withstand the harsh usage conditions mentioned above. Therefore, recently there has been a demand for bearings in which no surface layer is formed by overlay plating or the like. However, the current situation is that even this type of bearing cannot necessarily exhibit stable performance under the above-mentioned severe usage conditions.

That is, a bearing with an overlay on the surface has - JIS H5402, AJ-1 (10%
Sn, 0.75%Cu, 0.5%N1, Aj! Bad
), JIS H5402, AJ-2 (6% Sn, 2.
JIS such as 5%Cu, 1.0%N1, AJBaj1, etc.
Standard, SAE 780 (6%Si1.2%Si.1%C
u, 0.5%Ni, 0.1%■1, Aj! 'Ba/)
As shown in the SAE standard for ri, the bearing base metal part is made of a low Sn-A1 alloy with a relatively low Sn content, and the bearing surfaces of these bearing alloy parts are all covered with an overlay plating layer of a Pb-Sn alloy. is formed.

However, under recent high-load, high-temperature operating conditions, these bearings suffer from surface overlay ■I! It has become burnt out and has become unusable. On the other hand, bearings that do not have an overlay plating layer formed on their surfaces have S
AE 7g3 (20%Sn, 0.5%Si.1.0%C
u, 0.1%■1, Aj! As shown in Ba/),
It consists of a high Sn-Aj alloy with a high sn content. However, the alloy containing as much as 20% Sn has low hardness and cannot withstand high loads because the At matrix becomes weak.

In addition, regardless of the Sn content, bearing base metals in which PB is injected into Al-3N alloys to improve lubricity and provide seizure resistance are available, for example, by Ko Mizuno (Showa). This bearing base metal contains 10% Sn, 1.5% Cu, and 0.5%.
Al-3 containing Si and adding 3% PB
It is an n-Pb alloy.

Furthermore, in this Al-3n-Pb alloy, PbIfA
/Al-3n-Pb-Sb added with Sb was added to improve the dispersibility of this llb, since it has almost no solid moisture.
A series alloy is described in Japanese Patent Publication No. 52-12131, and furthermore,
Al-3 with Cr added for At matrix reinforcement
n-1'b-3b-Cr alloy was published in 1898
It is stated in No. 5. However, these Al-3n
-Pb-based alloys were developed for the purpose of improving lubricity during normal operation, and have the drawback of not exhibiting sufficient fatigue resistance under high-load operating conditions.

The reason for this is that the lubrication mechanism between the shaft and bearing under high load operation is fundamentally different from that under normal operation.

Therefore, basic studies were conducted on the lubrication mechanism under high load operation, and one of them was published in Japanese Patent Application Laid-Open No. 58-64336, in which coarse Si was dispersed and precipitated in an Al-3n alloy.
It is proposed by No.

This bearing has a cutting force due to the hard S1 precipitate, and because it has the cutting force, the surface unevenness of the mating shaft is scraped and flattened, improving the bearing performance.

To explain in more detail, on the surface of the mating shaft made of graphite cast iron on which spherical or flaky graphite has been precipitated, recesses remain after the graphite particles that fell off during the polishing process, and around these four parts there are hard work-hardened pallets. Convex portions such as edges and edges are generated. Therefore, the above-mentioned Al-Sn system, Al-Sn
- In a bearing base metal made of Pb or the like, abnormal wear is likely to occur during high-load operation due to these uneven portions. On the other hand, in the bearing base metal in which the coarse Si is precipitated in a dispersed manner, the cutting force is applied by the hard Si precipitates, so the uneven parts of the mating shaft are mechanically cut and flattened. , therefore,
No abnormal wear or seizure occurs.

However, when the mating shaft is made of a material other than graphite cast iron, during high-load operation, the surface of the mating shaft is scratched irregularly by coarse Si precipitates, causing seizure and causing major problems.

Problems to be Solved by the Invention The present invention aims to solve the above-mentioned drawbacks. Specifically, in the conventional Al-Sn bearing alloy, s is added to improve lubricity.
Elements such as Cr, Sb, Mn%Ni, etc. have been added for the purpose of increasing the content of n and pb, and further strengthening the At matrix, but these elements increase the hardness of the A/matrix. However, on the contrary, the A1 alloy becomes brittle and cannot be used under high temperatures (100~250℃) during high load operation.
It was found that it did not exhibit fatigue resistance at temperatures (0°C). Therefore, it is an object of the present invention to solve the problems in seizure resistance and wear resistance by precipitating 31 in an almost spherical shape in an alloy.

Therefore, the present invention focuses on the fact that bearing temperatures tend to rise with the recent increase in the output of engines, and that fatigue resistance is particularly strongly required at this high temperature.
Despite adding a matrix reinforcing element, Al-3n improves the brittleness of At alloys, increases fatigue resistance especially at high temperatures, and provides even higher seizure resistance and wear resistance.
bearing alloys.

to solve problems means and their effects That is, in the present invention, Sn is 1 to 20% at 1%.

0.1-5% pb, 1-10% Si and Gu%Mg
, Zn in one type or two or more types in a total amount of 0.
A containing 3 to 3.0%, with the remainder consisting essentially of Al.
In the l-3n series bearing alloy, more than 0.01% o and less than i% of Sb is added to disperse and precipitate Si particles in the Al matrix in the form of a sphere, an ellipse, or a shape with a rounded tip. It is characterized by having a structure that exists adjacent to a Pb alloy.

A more detailed explanation of the configuration of these means and their operation will be as follows.

First, the present invention was made to improve fatigue resistance under high temperature conditions.

In other words, in the conventional example, C, which is simply a high melting point element,
By adding R, Co, Ni, etc., it increases the mechanical strength, prevents the hardness from rapidly decreasing at high temperatures, and improves the wear resistance. However, like this, Ant-3n
Simply adding high-melting-point elements to increase the fatigue resistance of alloys at high temperatures increases hardness, but the alloy becomes brittle, resulting in lower tensile strength, elongation, and impact value, and bearing base metal No effective means have yet been found to increase fatigue resistance as a material.

In contrast, the present invention provides a bearing base metal suitable for severe conditions under high temperatures and high loads.
b is added as an essential component, this Sb acts on Si, and the spheroidization of the 31 crystals is made 8↑ from the time of casting.Furthermore, the spheroidization of the 81 crystals is increased by heat treatment, thereby making A.
Increases tensile strength, elongation and impact strength of l-3n alloy.

In other words, - Fatigue resistance is said to be due to the material's tensile strength, elongation, impact strength, structural structure, etc., and cannot be solved simply by adding bearing components. There is. As a result of repeated research by the present inventors regarding this point, they discovered such an effect of Sb, and based on this, the present invention was accomplished. Furthermore, even if the high R-point element as mentioned above is added to the Ant-3n alloy as an additive element, the addition of Sb can prevent the mechanical properties from deteriorating. properties will not deteriorate rapidly. These characteristics of the present invention can be supported by the fact that an improvement in fatigue strength was observed as a result of fatigue tests conducted at high temperatures and under high loads.

Furthermore, the present invention is suitable for high temperature and high load conditions in terms of surface structure, and has significantly improved surface performance due to dirt.

Generally, it is said that it is difficult to understand the burn-in phenomenon unambiguously because the process of reaching it is complex and many conditions act synergistically to achieve it. However, Pb on the surface
-Cu with Sn alloy overlay plating layer-
In Pb-based bearing alloys, this plating layer wears out under high-load operation, leading to seizure, whereas in At-3n-11b-based alloy bearings containing Si, Cu, etc., an overlay plating layer is formed on the surface. There is a phenomenon that does not lead to burn-in even though it is not done.

The inventors of the present invention focused on this phenomenon and compared the two bearings structurally. That is, FIG. 3 is an enlarged cross-sectional view of a part of a bearing that has an overlay plating on its surface.
FIG. 4 is an enlarged sectional view of a part of a bearing made of Al-3n-pb alloy, which has no overlay metal on its surface and contains Si and Cc+9. As is clear from Figure 3 (,
This bearing has surface overlay plating [4, Alloy I15
The entire surface of the overlay plating layer 4 supports the axial load. In contrast,
As shown in Figure 4 (31, Al-3n-pb alloy,
The bearing containing Cu etc. consists of alloy II5 and backing metal 6,
There are rod-shaped and flaky Si in the matrix of this alloy 1i15.
Particle 2 is precipitated. Therefore, in this bearing, the load of the mating shaft is supported by the hard 31 particles 2, and moreover, the Si particles have the cutting force as described above.

In short, the difference between the two is surface contact and point contact, and this difference makes a decisive difference in lubrication and temperature rise of the FJ friction surface. In other words, in surface contact like the bearing shown in Fig. 3, under high speed and high load conditions, 11! While the temperature of the m-plane increases rapidly, in point contact as in the bearing shown in Fig. 4, a gap is formed between the surface of alloy 8i5 and the surface of the mating shaft, and the oil film in this gap does not accumulate much. Since no large weight is applied, sufficient lubrication is maintained and temperature rise on the friction surfaces is suppressed.

Proceeding further, the present inventors based on the basic viewpoint that supporting shaft loads through point contact as shown in Fig. 4 is extremely effective for lubrication under high loads, and in order to make the most of the effect. Through research on the composition and structure of the bearing base metal according to the present invention, they completed research on the composition and structure of the bearing base metal.

Specifically, the present inventors have discovered that the Al-3n-Pb alloy contains Sl, Cu, etc. in the bearing base metal.
Focusing on the precipitation form of silica, we conducted research on the effect of this form on the lubricating surface. First, we found that sl is a stable substance with a high melting point, has strong nonmetallic properties, and 200℃~5 for main component Fe
It was found that St is extremely suitable as a point support means for the axial load because it does not cause any diffusion or dissolution even if it comes into contact at a high temperature of about 00°C.

Second, when the mating shaft is point-supported through the 'a film, the 31 particles are so hard that their Gockers hardness reaches 599;
Moreover, since Si particles are not a compound, they are brittle (and have great elasticity and can withstand sudden fluctuations in load).

However, although Sl has the above-mentioned properties, it has strong crystallinity (even in the form of eutectic precipitation with A/,
It has a plate-like or rod-like shape, and its shape changes only slightly even if it undergoes rolling or heat treatment during the bearing manufacturing process. Therefore, if the precipitation form of Si particles is not controlled, as shown in FIG.
The 81 particles 2 precipitated together with the -pb alloy particles are plate-shaped or rod-shaped, and the Sn-Pb alloy particles 3 are present apart from the 81 particles 2. In this state, the edges of the negative 81 particles 2 tend to scrape and damage the mating shaft, and on the contrary, the lubricity deteriorates and seizure occurs.

From this point of view, in the present invention, in order to dramatically improve lubricity, the cutting force is removed from the 81 particles, and the particles are shaped into a shape with rounded edges, such as a spherical shape.

That is, FIG. 1 is an enlarged cross-sectional view of a part of a bearing base metal according to one embodiment of the present invention, and as shown in FIG.
The i-particles 2 are spherical, and the spherical Si particles 2 bring the contact closer to the ideal point contact, thereby further increasing lubricity and wear resistance. Furthermore, even if a high load is suddenly applied at high speed, the mating shaft will not be damaged. Also, Si
Since it is spherical, there is no notch effect in the matrix, and a matrix with stable strength can be obtained, and it also has excellent wear resistance.

This spheroidization of Si particles occurs at the eutectic point A1 where Sl precipitates.
This can be achieved by improving the properties of the alloy liquid phase, and (
In addition, Sb is effective as an additive element.

Furthermore, when Sb is added, the precipitation form of the Sn-Pb alloy particles 3 changes, and as shown in FIG.
The Sn--Pb alloy 3 is present more adjacent to the surface. This structure is that of a conventional example (for example, see Figure 5)
Dramatically improves lubrication performance compared to

In addition to solving the surface performance in principle as described above,
There is a need to strengthen the matrix at high temperatures.

That is, %At is highly sensitive to heat, and if the temperature exceeds 150°C, it will soften (HV10 or less) and lose its strength. In order to prevent this softening, precipitation hardening matrix reinforcing elements such as Or, Mn%F
By adding e, Go, Ni, Ti, VlZr, etc., selecting one type or 2n1 or more of these reinforcing elements, and performing appropriate heat treatment, the strength at high temperatures can be further increased.

As described above, in the present invention, in addition to adding base strengthening elements to the width as in the past, Sb is added together with these reinforcing elements to improve not only the hardness (but also the tensile strength and elongation) compared to the past. The purpose is to increase fatigue resistance and improve bearing performance under high v1 heavy operation.The mechanism and composition of each component are explained as follows.

In the bearing with the configuration shown in Fig. 1, the lubricating surface that disturbs the shaft load is the tip of the 31 particles 2 protruding from the surface of the matrix 1, and the 'a film is interposed between the 31 particles and the mating shaft. and fluid lubrication is maintained. However, when subjected to sudden fluctuations in load, this oil lIJ ruptures and local boundary lubrication slows down. At this time, if a Sn-Pb alloy film is interposed on the upper surface of the Si particles 2, seizure can be prevented. , the oil film is normally regenerated and a state of fluid lubrication is quickly restored. Also at this time, with the structure shown in FIG. 1, Sn-pb alloy particles 3 exist near the 31 particles 2, and this alloy has an affinity for lubricating oil even in the molten state.
Therefore, it is difficult to run out of oil. Also, the mating shaft and 31
Even if the 81 particles become high temperature due to friction with the particles, the 5i-P
Heat is absorbed by the heat of fusion of b, making it difficult for seizure between the nearby Al alloy of the matrix and the mating shaft. Also, at this time, as shown in FIG.
At least a portion of the Pb alloy particles 3 are in a liquid phase, and this liquid phase 3 is supplied to the protruding surfaces of the atfSi particles 2. This supply amount changes as the temperature rises, and since the Sn-Pb liquid phase 3a is always present on the lubricated surface of the Si particles 2,
Overheating can be prevented. In short, the structure in which the Si particles 2 are spherical and the Sn-Pb alloy particles 3 are adjacent to the edges is very effective in boundary lubrication conditions (oil film has broken), and even in normal fluid lubrication conditions, it is hard. 81 Particles 2 suitably fit into the mating shaft and are soft Sn-
It is covered with PBL, which acts like a shock absorber.

Furthermore, in order to obtain an excellent lubricating surface, 31 particles and Sn-P
b A strong matrix is required to support the alloy particles. That is, the reasons for the limitations as described in the claims and the effects (including synergistic effects) thereof will be listed for each element.

(11Sn7-20%: Sn exists dispersed in the At matrix together with PB, and is a metal that is responsible for the seizure resistance, embeddability, and conformability that bearings basically require. If it is less than 7%, the resistance The effect on seizure properties is small, and when it exceeds 20%, the Sn phase becomes three-dimensionally continuous,
Detracts from strength.

t21 Pb O, 1 to 5%: Pb coexists with the above-mentioned Sn, further improves the seizure resistance, embeddability, and conformability of So, and has excellent lipophilicity and non-adhesiveness, and Even the addition of can dramatically improve lubrication performance. If the amount is less than 0.1%, the above effect cannot be achieved at a constant thickness, and if it exceeds 5%, Sn will substantially coexist in the At matrix, making it virtually impossible to uniformly disperse it.

(3) s* 1 to 10%: An important element that imparts anti-seizure properties, load resistance, and wear resistance to Al shaft bearings.If it is less than 1%, no effect is observed;
If it exceeds %, the alloy becomes hard and loses ductility, which actually impairs load-bearing properties.

(4) One or more of Cu, Mg, and ln 0
．． 3-3%: Cu%M is A! Appropriate heat treatment with basic elements that strengthen the matrix results in constant thickness effects. If the amount is less than 0.3%, no effect will be observed, and if it exceeds 3%, it will form a compound with Al, which will actually inhibit the ductility of the material.

(5) Sb 00OIHA less than 0.1%: Sb is 81
It has the effect of dispersing and precipitating particles in a spherical, oval, or rounded tip shape. In order to have this effect, it is most preferable to add more than 0.01 and less than 0.1%.
, If it is less than 0.01%, it does not affect the shape of Si particles, and if it is added more than 0.1%, it will precipitate inside the Sn phase, and 31
Not useful for particle improvement.

Example Next, examples of the present invention will be described.

Example 1 First, an Al-Sn bearing alloy having the composition shown in Table 1 was cast as a plate material with a thickness of 20M by continuous casting, and the upper and lower surfaces of each cast billet were 1. After OH surface milling, the material was reduced to a thickness of 2III11 by cold rolling.

In this state, heat treatment is performed at 300 to 350°C to remove distortion, and then the car is ready! A bearing with a thickness of 1.50 mm was obtained by pressing the iron plate of the backing metal through the thin plate.

Among these bearings, test materials NL1-6 are test materials of comparative examples, &7-11 are those according to the present invention, and N.7
-11 is one in which Sb is added for spheroidization of 81, and Cu and/or M (1) is added for matrix addition.

Each of these test materials was used as a bearing at normal temperature and
To examine the mechanical properties at 00°C, tensile strength, elongation and hardness tests were carried out and are shown in Table 2. In addition, each sample material was made by removing the backing metal by machining and turning it into Al-S.
Only the n alloy part is used, and the shape of the test piece is JIS z 22.
01 No. 5.

From these results, test materials 7 to 11 showed less strength loss at high temperatures (200°C) than the test materials of comparative examples, and
The effect of adding 1 and 1' or Mg can be seen. In other words, it is thought that the spheroidization of Si and the reinforcement of matrix 2 are mutually separated, resulting in improved strength and elongation. Furthermore, the elongation was improved compared to the conventional example, and it can be said that the overall mechanical properties at high temperatures were improved.

Next, in order to find out the seizure resistance and abrasion resistance of the sample materials, a test was conducted using a Suzuki type friction and wear test tube, and the test conditions were as follows.

Masatsu speed 4R1/Sec Compatible material 345G, hardness) IIIC = 55 surface roughness 0
．． 8-1. O3 Oil used: SAE, 20v-40 oil layer
150±5℃ Seizure load 1 100kg/cr or 6101a)/al 5
Wear resistance: Increase the blood pressure every 15 minutes until seizing occurs using tep, and use the blood pressure at which seizing occurs as the seizing load.On the other hand, to check the wear resistance, 100 klJ/
The test was conducted at a constant l112 for 6 hours, and the changes in the interlayer thereafter were observed. The results are shown in Table 2.

According to this, all of sample materials 1 to 11 showed better seizure resistance and wear resistance than the sample materials of comparative examples, and Sbg
It can be seen that the surface performance is also improved by adding 11 and matrix reinforcing elements.

This indicates that the alloy according to the present invention has an excellent lubrication mechanism.

Next, we processed each sample material into a bearing shape and conducted a final bearing fatigue test.
The results shown in the table were obtained. This test was carried out under the following conditions by fixing the bearing to the connecting rod and applying an eccentric load to the shaft, which is almost the same as the conditions of a real engine. This is a test that evaluates the length between FJ#s held.

Note that the test conditions are as follows.

Surface pressure 600k (If/c12 Number of revolutions 400Or, p, m Mating material FCD
70, roughness 0.8~1.5S oil used SAE
20v-40 Oil temperature 150℃±5℃ Note that the upper limit of this test vtm is 300 hours, and N=
The average values of 5 are shown in Table 2. As a result, all of them showed a longer durability time than the sample materials of comparative examples, and the alloy according to the present invention had excellent fatigue resistance. The changes in the form of Sl in the case (sample material &9) are shown in FIGS. 6 and 7. That is, FIG. 6 and FIG. 1 are explanatory diagrams showing the microscopic structures of the conventional alloy and the alloy according to the present invention. In particular, each sample was deeply etched so that the shape of 81 grains could be seen, This image was removed using an electron microscope. As can be clearly seen from these drawings, as shown in FIG. 6, in contrast to the conventional example in which the particles 2 are not spherical at all, in the present invention, 31 particles 2 are formed due to the addition of Sb.
It can be seen that the edges are spherical.

Example 2 In order to confirm whether or not the bearing base metal according to the present invention has the effect of improving the brittleness of the alloy by adding a high melting point metal etc. as a reinforcing agent to the A/matrix, impact was measured as a substitute property. The values were measured, and the improvement effect due to the effect of adding Sb was determined through experiments.

As test materials for the experiment, &5, which is a comparison material shown in Table 1 of Example 1 and which does not contain Sb, and N@ which is a chino material according to the present invention.
A comparative experiment was conducted in , 9.

The experiment was conducted using a No. 3 test piece (r+=5) using the Charpy impact test method in accordance with JIS 22242.

As a result of the experiment, the conventional material had an average value of 0.84 kg・m/CI2, but the material according to the present invention had an average value of 3.15 kq・f
fl/[)2, and it was clear that the bearing base metal according to the present invention had an improvement effect due to the addition of Sb.

Example 3 In order to understand the influence of differences in Sbm on the At-3-hole alloy, a plate-like material with a thickness of 20 mm was cast from a 730° C. molten metal containing the components shown in Table 3. The circularity coefficient of the shape of 81 grains in the cross-sectional structure of this VI material was determined using an image processing device.

In addition, a test piece No. 144 specified in JIS 22201 was cut from this cast material, and its mechanical properties were found to be 0.06% from 0.2% (comparative material) as shown in Table 4.
The 31 grains of (Hon! fi invention material) are noticeably circular, and the mechanical properties are also improved, especially the energy value, which substitutes for energy absorption until the material breaks, has increased by about 10%. are doing.

From these things, Sll! The material of the present invention, which contains 0.1% 1, has a clear difference in properties compared to the conventional material.

・Effects of the invention> As explained in detail above, the present invention has a serious disease rate of 7 to 20%.
%Sn, 0.1 to 5% Pi), 1 to 10% Si, and one or more of Cu, Mg, and In in a total amount of 0.3 to 3.0%, The remainder is essentially A/
In this At-Sn bearing alloy, more than 0.01% but less than 0.1% of Sb is added to the At matrix.
The bearing base metal of the present invention with this structure has a structure in which one particle is dispersed and precipitated in a spherical, elliptical, or rounded tip shape and exists adjacent to the Sn-Pb alloy. Excellent lubricity, 100-25
This bearing base metal has extremely good mechanical properties at a high temperature of 0°C and can fully withstand the harsh conditions of use caused by high-load operation.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a part of a bearing base metal according to one embodiment of the present invention, FIG. 2 is an explanatory view of the side of the lubrication R of the bearing base metal shown in FIG. Fig. 4 is an enlarged sectional view of a part of a conventional bearing, Fig. 5 is an enlarged sectional view of a part of the bearing base metal of Fig. 4, and Fig. 6 shows the structure of the bearing base metal of the conventional example. Explanatory drawing, FIG. 7 is an explanatory drawing showing the structure of the bearing base metal according to the present invention. Code 1...Matrix 2...Si particles 3...Sn-Pb alloy particles 3a...Sr+-Pb liquid phase 4...Overlay Metsuki decoy 5...Bearing base metal turn 6...Back metal Fig. 1 3srl-pb Mikunada + / Fig. 2 Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] 1) 1-20% Sn, 0.1-5% Pb, 1-20% by weight
Contains 10% Si and one of Cu, Mg, and Zn alone or two or more in a total amount of 0.3 to 3.0%,
In an Al-Sn bearing alloy where the balance is essentially Al, adding more than 0.01% but less than 0.1% of Sb to make Al
Si particles are dispersed and precipitated in a matrix in the form of a sphere, an ellipse, or a shape with a rounded tip.
1. An Al--Sn bearing alloy characterized by having a structure that exists adjacent to a b-alloy.