JPH0277542A - Al-sn bearing alloy - Google Patents

Abstract

PURPOSE:To obtain the title bearing alloy capable of high-speed and high-load driving and having excellent fatigue resistance, seizure resistance and wear resistance at high oil temp. by adding and incorporating specific amounts of Sb to an Al-Sn bearing alloy contg. the elements for the strengthening and hardening of Si and matrix metal. CONSTITUTION:To an Al-Sn bearing alloy having the compsn. contg., by weight, 7 to 20% Sn, 0.1 to 5% Pb and 1 to 1 0% Si, furthermore contg. total >0.01 to <1.0% of one or more kinds of elements improving the hardness and strength of matrix metal among Cr, Mn, Fe, Ni, Co, Ti, V, Zr, etc., and the balance Al, >0.01% to <0.1 % Sb is added. By the addition of Sb, hard Si grains 2 having spherical shape or roundish shape in the tip are dispersed and precipitated in an Al matrix 1 having improved strength and hardness by the metal to be added such as Cr and Sn-Pb alloy grains 3 easy to form a liquid phase 3a are precipitated adjacently to the Si grains 2 to form a lubricating oil film between the Si grains projecting from the surface of the matrix and the sliding mating members, by which the bearing alloy having excellent characteristics can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an AJ-Sn bearing alloy, and more specifically, Si particles are precipitated in a matrix in a spherical or nearly spherical shape, and which is suitable for high-speed and high-load operation. In particular, the present invention relates to an Al-8n bearing base metal which is particularly excellent in fatigue resistance, seizure resistance, and wear resistance under high oil temperatures.

Conventional technology Recently, automatic 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 increased, and the operating conditions of the bearings have changed. is becoming increasingly severe. From this point of view, in conventional multi-component systems, Al systems, etc., the surface of the bearing base metal is formed with 1) b-Sn system surface (2) by overlay plating, etc., but in bearings with this structure, lubrication Due to the high temperature of the surface, fatigue and seizure phenomena occur, making it unable to withstand the harsh usage conditions mentioned above. Therefore, recently there has been a demand for bearings in which no space between surfaces 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.

In other words, bearings with an overlay plating order on the surface must have - JIS I+ 5402, AJ-1 (1
0%Sr+, 0.75%Cu, 0.5%N1, A I
Bal, JIS H5402, AJ-2+6
%Si1.2,596Cu, 1.0%N1, A/Ba/
) etc. JIS standards, SAE 7130+6%5O12%
Si. 1%Cu, 0.5%Ni, 0. ? 9(, Ti
, AllualW's 5AEXJ! As shown in the figure, the bearing alloy part is low Sn-A with relatively low SO content.
J alloy, and an overlay plating layer of a Pb--Sn alloy is formed on the bearing surfaces of these bearing alloy parts.

However, in recent years, under the high-load, high-temperature operating conditions, the overlay plating II on the surface of these bearings has worn away, resulting in seizure, making them unusable. In contrast,
Bearings that do not have overlay plating on the surface are SA
E 783 (20%Sr+, 0.5%Si.1.0%C
u, 0.1% ■1, llBa1l, Sn
Containment Ii! It consists of a high Sn-At base metal.

However, alloys containing as much as 20% Sn have low hardness and cannot withstand high loads because the Ag matrix becomes weak.

In addition, regardless of the Sn content, bearing base metals in which I)b is added to At-Sn alloys to improve lubricity and seizure resistance are available, for example, by Kou Mizuno, published in 1953. This bearing base metal contains 10% Sn, 1.5% Cu, 0.5% Si, and 3% Pb is added to A Calo. Al-Sn
- It is a Pb-based alloy.

Historically, in this Al-Sn-P'O alloy, PbtfA
Since there is almost no solid solution with pb, in order to improve the dispersibility of pb, Al1-Sn-Pb~S to which Sb is added is added.
B-based alloys are described in Japanese Patent Publication No. 121-121-1988, and furthermore, 8L alloys are added with Cr to strengthen the At matrix.
-Sn-Pb-3b-Cr alloy was published in 1989-189
It is described in No. 85. However, these A l −
The Sn-Pb alloy was developed with the aim of improving lubricity during normal operation, and has sufficient f! under high-load operating conditions.
4) It has the disadvantage of not exhibiting fatigue properties.

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 the studies was published in Japanese Patent Application Laid-Open No. 58-64336, in which coarse Sl was dispersed and precipitated in an Al-Sn 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 polishing, and the area around these four parts is hard and work-hardened. Convex parts such as peaks and edges are generated. Therefore, Al1-8n system as mentioned above, Al-
In a bearing base metal made of 8n-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 Sl is dispersed and precipitated, the hard S
Since the cutting force is applied by the precipitates of 1, the uneven portions of the mating shaft are mechanically cut and flattened, so that abnormal wear and seizure do not occur.

However, if the mating shaft is made of a material other than graphite cast iron, the coarse S1 precipitates may scratch the surface of the mating shaft irregularly during high-load operation, 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 A/-Sn bearing alloy, s is added to improve lubricity.
Elements such as Cr, Sb, Mo, and N+ have been added for the purpose of increasing the content of n and llb, and further strengthening the 11 matrix, but these elements cannot increase the hardness of the Al matrix. Even if it is possible to do so, the A1 alloy becomes brittle and must be used under high temperatures (100~200℃) during high load operation.
It was found that it did not exhibit fatigue resistance at temperatures (50°C).

Therefore, it is an object of the present invention to solve the problems in seizure resistance and wear resistance by precipitating Si in an almost spherical shape in the alloy.

Therefore, the present invention focuses on the fact that the bearing temperature tends to rise with the recent increase in the output of engines, and that fatigue resistance is particularly strongly required at this high temperature.
Al-Sn improves the brittleness of the A1 base metal, improves fatigue resistance especially under high temperatures, and provides even higher seizure resistance and wear resistance despite the addition of matrix reinforcement Genkyoga.
bearing alloys.

Means for solving the problem and its operation, that is, the present invention solves the problem by weight? 1-20% sn, 0.
1-5% PI), 1-10'? 4 S i, including C
r, Mn, [e, N1.001 1, V%11.
% but less than 1.0%, with the remainder substantially consisting of Al, in an Al1-Sn bearing base metal containing more than 0.01% and less than 0.1%.
% of Sb is added to disperse and precipitate Si particles in the i-matrix in a spherical, elliptical, or rounded-tip shape, resulting in a structure that exists adjacent to the Sn-Pb alloy. It is characterized by

Now, the structure of these means and their operation will be explained in more detail as follows.

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

That is, in the conventional example, C, which is simply a high melting point element,
Addition of R, Co, Ni, etc. increases high-temperature strength, prevents sudden decrease in hardness at high temperatures, and improves wear resistance. However, in this way, Al-8n
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 alloy suitable for severe conditions under high temperatures and high loads.
B is added as an essential component, and this Sb acts on Si to make the Si crystals spheroidized from the time of casting.Furthermore, heat treatment increases the spheroidization of the 81 crystals in the mouth, thereby making A.
Increases tensile strength, elongation and impact strength of t-Sn alloys.

In other words, - Fatigue resistance within the film is due to the tensile strength, elongation, impact strength, organizational structure, etc. of the material, and cannot be solved simply by adding bearing components. has been done. 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, in the present invention, even if a high melting point element is added to the Al-Sn alloy as mentioned above, the addition of Sb can prevent the deterioration of mechanical properties. No sudden deterioration of characteristics. Such W characteristics of the present invention can be supported by the fact that an improvement in cross-sectional strength was observed as a result of fatigue tests conducted at high temperatures and under high loads.

Further, the present invention is suitable for high temperature and high load conditions in terms of the surface set a configuration, and thereby the surface performance is significantly improved.

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
-Sn alloy overlay plating + ae formed Cu
-For Pb bearing alloys, this plating 1 is F under high load operation.
In contrast, bearings made of Al-Sn-I'b alloys containing Sl, Cu, etc. do not suffer from seizure, even though no overlay plating layer is formed on the surface. There are phenomena that cannot be achieved.

Therefore, the inventors of the present invention took note of this phenomenon and installed both bearings with M4
A structural comparison was made. That is, FIG. 3 is an enlarged sectional view of a part of a bearing having an overlay plating layer on the surface, and FIG. 4 is an enlarged sectional view of a bearing having an overlay plating layer on the surface, and FIG. FIG. 2 is an enlarged cross-sectional view of a portion of the bearing including the bearing. As is clear from Figure 3,
This bearing has surface overlay plating @4, alloy! I!
5 and a back metal 6, and the axial load is supported by the entire surface of this overlay plating layer 4. On the other hand, as shown in Fig. 4, 81
, CU, etc., is made of alloy 1ii5 and back metal 6, and rod-shaped or flaky Si is included in the matrix of alloy H5.
Particle 2 is precipitated. Therefore, in this bearing, the vI weight of the mating shaft is supported by the hard Si particles 2, and moreover, the Si particles have cutting force as described above.

In short, the difference between the two is surface contact and point contact, and this difference allows for lubrication, 11! There is a decisive difference in the temperature rise on the m-plane. In other words, like the bearing shown in Figure 3,
In surface contact, the temperature of the FJI surface rises rapidly under high-speed, high-load conditions, whereas in point contact, as in the bearing shown in Figure 4, the temperature between the surface of alloy layer 5 and the surface of the mating shaft increases. A gap is formed, and since a very large load is not applied to the oil film in this gap, sufficient lubrication is maintained and the upper limit of the degree B of the friction surface is suppressed.

Going forward, the present inventors took the basic viewpoint that supporting shaft loads through point contact as shown in Figure 4 is extremely effective for lubrication under high loads, and took full advantage of its effects. Through research on the composition and structure of the bearing base metal according to the present invention, they were able to complete the bearing base metal according to the present invention.

Specifically, the present inventors focused on the form of precipitation of Sl in the bearing base metal, which is an Al=Sn-Pb alloy and contains Sl, Cu, etc., and investigated the effect of this form on the lubricating surface. As a result of our research and research, we found that, firstly, Sl is a stable substance with a high melting point, and has strong nonmetallic properties, so that it can react with Fe, the main component of the mating shaft, at 200°C to 50°C.
It has been found that Sl 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.

Secondly, when the mating shaft is point-supported through an oil film, the Si particles are so hard that their Vickers hardness reaches 599, and since the 81 particles are not a compound, they are not brittle, have high elasticity, and are subject to rapid fluctuations. It was found that it could withstand the load.

However, although Sl has the above-mentioned properties, it has strong crystallinity (,A/in any eutectic precipitation form,
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. For this reason, if the precipitation form of Si particles is not buried, as shown in FIG.
The Si 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 Si particles 2. In this state, the edges of the hard Si particles 2 cannot scrape the mating shaft and are likely to attach, and on the contrary, the lubricity is reduced 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 Si particles, and the Si particles are buried in a shape that gives rounded edges, such as a spherical shape.

In other words, FIG. 1 is an enlarged sectional view of a part of a bearing base metal according to one embodiment of the present invention, and as shown in FIG. S to do
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, Sl
Since it is spherical, there is no notch effect in the matrix, making it possible to obtain a matrix with stable strength and wear resistance.

This spheroidization of Si particles is caused by At at the eutectic point where Sl precipitates.
This can be achieved by improving the properties of the alloy liquid phase, and Sb is particularly 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. The structure of the mouth dramatically improves the lubrication performance compared to the conventional example (see, for example, FIG. 5).

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

That is, Al is highly sensitive to heat, and if the temperature exceeds 150°C, it will soften (below HVIO) and lose its strength. In order to prevent this softening, precipitation hardening matrix reinforcing elements such as Or, Mn,
Add Fc, Go, N1, D1, V, lr, etc.,
By selecting one or more of these reinforcing elements and performing appropriate heat treatment, the strength at high temperatures can be significantly increased.

As described above, in the present invention, in addition to simply adding base reinforcing elements 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 load 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 supports the axial load is the tip of the Si particles 2 protruding from the surface of the matrix 1, and an oil film is interposed between the Si particles and the mating shaft, and the lubricating surface that supports the axial load is Maintains lubrication. However, when subjected to sudden and fluctuating loads, this oil film ruptures and locally reaches boundary lubrication.
At this time, if a Sn-Pb alloy film is interposed on the upper surface of the Si particles 2, seizure can be prevented and the process can be performed normally.
The a-film is regenerated and the state of fluid lubrication can be quickly restored. In this case, too, in the structure shown in FIG. 1, there are Sn-P alloy particles 3 in the vicinity of the Si particles 2, and this alloy has an affinity for lubricating oil even in the molten state. Less likely to break. In addition, even if the 81 particles reached a high temperature after 7 frictions between the other axis and the S: particle, the 5i-Pb
This heat is absorbed by the heat of fusion, making it difficult for the nearby 7-trix Al alloy to seize with the mating shaft. Also, at this time, as shown in FIG. 2, Sn − adjacent to the Si particles 2
At least a portion of the Pb alloy particles 3 are in a liquid phase, and this liquid phase 3a is supplied to the protruding surfaces of the Si particles 2. This supply amount increases as the temperature increases, 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 2If are spherical and the Sn-Pb alloy particles 3 are adjacent to them is very effective in the boundary lubrication state (oil film has broken), and even in the normal fluid lubrication state, the hard Si particles 2 fits the opponent shaft appropriately and is soft 5L)
It is covered with -pb■, which acts like a stain absorber.

Furthermore, in order to obtain an excellent lubricating surface, Si particles and Sn-p
b) A strong matrix supporting the alloy particles is not required. In summary, the reasons for the limitations as described in the claims and their effects (including synergistic effects) 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 No seizure effect can be obtained, and if the content exceeds 20%, SnIi@ becomes three-dimensionally continuous, impairing the strength.

+21 Pb O, 1 to 5%: Pb coexists with the above-mentioned Sn and further improves the seizure resistance, embedding property, and conformability of SO, and has excellent R'a properties and non-adhesive properties, Even the addition of 90% improves the lubrication performance dramatically. If the poison is less than 0.1%, the above effect cannot be achieved at a constant thickness, and if it exceeds 5%, it will substantially coexist with Sn in the At matrix, making it virtually impossible to uniformly disperse it.

13) Si 1 to 10% An important element that imparts anti-seizure properties, load resistance, and wear resistance to diAt 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) Cr, Mn, Fe, Ni, Co%Ti
%V%Zr, one or more of them alone or in the market more than 0.01% but less than 1.0%: All of these elements are elements that tend to form compounds, and 9 different additions can create a matrix. It can increase hardness and strength. In particular, when added in an appropriate amount, it is effective in improving fatigue resistance, wear resistance, and maintaining strength at high temperatures. If the additive amount is less than 0.01%, there is no effect, and if it is more than 1%, the compound becomes coarse and the alloy strength is reduced. In addition, if elements are added to this, it is possible to prevent the coarsening of Sn particles, and among these, the effect of Cr has been reported, but the same effect can be obtained by adding these elements in addition to Cr. It can be achieved. At this time, the Cr content can be further increased by adding Cr and other elements.

In other words, if cr is present in too much of these elements, as is well known, it will form intermetallic compounds with At, making it impossible to finely disperse it, which is undesirable. In this point,
If other elements are added in addition to Cr, even if an intermetallic compound with At is formed, it can be finely dispersed, and the other elements can also achieve the same improvement in bearing performance.

(51Sb O, more than 01% and less than 0.1%2Sb has the effect of dispersing and precipitating Si particles in a spherical, oval, or rounded tip shape. In order to have this effect, 0.01% % but less than 0.1% is most preferable, o, oB 6 or less does not affect the shape of the 81 particles,
Moreover, even if it is added in an amount of 0.1% or more, it will precipitate inside the SO phase and will not be useful for improving the Si particles.

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 20 mm by continuous casting, and the upper and lower surfaces of each cast billet were milled and then cooled. It was rolled down to a thickness of 2 mm by inter-rolling.

In this state, a heat treatment was performed at 300 to 350° C. to remove strain, and then a thin KAl plate was crimped onto an iron backing plate to obtain a bearing having a thickness of 1.50 mm.

Among these bearings, test materials No. 1.1 to 5 are test materials of comparative examples, and No. 6 to No. 20 are those according to the present invention.
Among these, Sb is added to Nt 6 to 13 for 81 spheroidization, and Cr, Mn, Fe, Go, N1,
1, V, lr added, sample material M@,
14 = 20 is obtained by adding an appropriate combination of the above additive elements.

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 using 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 6 to 20 show less strength loss at high temperatures (200°C) than conventional materials, and have Cr, M
The effects of adding n%Fe, co, N1, 1, V, and Zr can be seen. In other words, it is thought that the spheroidization of Si and the reinforcement of the matrix were mutually effective to improve the 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 wear resistance of the test material, the Suzuki method Is! The test was carried out using an abrasion tester, and the test conditions were as follows.

Masatsu speed 41m/See Compatible material 345C% Hardness HIIIC = 55 Surface roughness 0.
8-1. O8 Oil used: SAE, 20v-40 Oil temperature: 150±5℃ Seizure load: 100kq #kara 10kq/Cl2Step
Wear resistance is measured by increasing the blood pressure every 15 minutes until F seizure occurs, and using the surface pressure that causes seizure as the seizure load.On the other hand, in order to check the wear resistance, 100 kq/[
The test was conducted at a constant temperature of 1 for 6 hours, and the results of the subsequent changes in severe disease are shown in Table 2.

According to this, all of test materials 6 to 20 exhibit better seizure resistance and wear resistance than conventional materials, and it can be seen that the addition of Sb2 and matrix-strengthening elements also improves surface performance. . This shows that the alloy according to the present invention has an excellent lubrication R structure.

Next, each sample material was actually processed into a bearing shape, and R
When we conducted the final bearing fatigue test, the second
The results shown in the table were obtained. This test was conducted under the following conditions, with the bearing fixed to the connecting rod and an eccentric load applied to the shaft, almost the same as in an actual engine, and the performance was maintained without seizure or damage. This is a test that evaluates the length of time.

Note that the test conditions are as follows.

Surface pressure 600kgf10' rotation
Number 400Or, p, 11 Mating material FCD
70, roughness 0.8~1.5S oil used SAE
20w-40 Oil temperature 150℃±5℃ The upper limit of this test time is 300 hours, N=5
The average values are shown in Table 2. As a result, the alloy of the present invention has excellent fatigue resistance, and the conventional alloy has an additional 0.03% Sb content. Figures 6 and 7 show the changes in the morphology of Sl when it is added (sample material &7).
It was as shown in the diagram. That is, FIGS. 6 and 7 are explanatory diagrams showing the microscopic structures of the conventional alloy and the alloy according to the present invention. It is etched and photographed using an electron microscope.As can be clearly seen from these drawings, as shown in Fig. 6, in the conventional example, the particles 2 were completely (not spherical), whereas in the present invention, the particles 2 were Sb-shaped. It can be seen that the edge portions of the Si particles 2 become spherical due to the addition.

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 Al matrix, the impact value was measured as a substitute property. was measured, and the improvement effect due to the addition of Sb was determined through experiments.

As sample materials for the experiment, a comparative experiment was conducted using Na5, which is a conventional material that does not contain Sb, shown in Table 1 of Example 1, and Tori 20, which is a material according to the present invention.

The experiment was conducted using a No. 3 test piece (n-51) according to JIS Z 2242 and the Charpy impact test method.

As a result of the experiment, the conventional material had an average of (110,84klJ -a+
/r12, but the one according to the present invention has an average value of 2.8
5klJ·m,'v, 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 the difference in 5bat on the At-Sn alloy, a plate-like material with a thickness of 20 mm was cast from a molten metal at 730°C containing the components shown in Table 3. The circularity coefficient of the shape of the Sl grains in the cross-sectional structure of this cast material was determined using an image processing device.

In addition, a test piece No. 14A specified in JIS 22201 was cut from this cast material, and its mechanical properties were found to be 0.06% (Sbm) than 0.2% (comparative material) as shown in Table 4.
In the invention material), 81 grains are significantly more circular,
The mechanical properties have also been improved, and in particular, the energy value, which represents the amount of energy absorbed until the material breaks, has improved by about 10%.

From these things, Sb! ! The material of the present invention containing 0.1% I is clearly different in properties compared to the conventional material.

<Effects of the Invention> As explained in detail above, the present invention has a weight ratio of 7 to 20% by weight.
%5O10, 1-5% pb, 1-10% Si, C
r, Mn%Fe, Ni, CO5■+, V, 7r
One or more of these can be used alone or in combination for 0.
In an At-Sn bearing alloy containing more than 0.01% but less than 1.0% and the remainder substantially consisting of Al,
It consists of a structure in which less than 1% of Sb is added and 81 particles are dispersed and precipitated in an At matrix in a spherical, elliptical, or rounded-tip shape, and exist adjacent to the Sn-Pb alloy. The bearing alloy of the present invention having this structure has extremely excellent lubricity and has a lubricity of 100 to 2
It has extremely good mechanical properties at a high temperature of 50°C,
This is a bearing alloy that can withstand the harsh conditions of 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 diagram of the lubrication mechanism of the bearing base metal shown in FIG. 1, and FIGS. 3 and 4. 5 is an enlarged sectional view of a part of the bearing base metal of the conventional example, FIG. 5 is an enlarged sectional view of a part of the bearing base metal of FIG. 4, and FIG. 6 is an explanatory diagram showing the structure of the bearing base metal of the conventional example. FIG. 1 is an explanatory diagram showing the structure of a bearing base metal according to the present invention. Code 1...Matrix 2...Si
Particle 3...Sn-Pb alloy particle 3a...Sn-Pb liquid phase 4...Overlay plating layer 5...Bearing alloy ll! 6...Secret fund patent applicant KoNDC Co., Ltd. Agent Patent attorney Yoshikatsu Matsushita Attorney Fumi Soejima Figure 1 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1) 7-20% Sn, 0.1-5% Pb, 1-20% by weight
Contains 10% Si, Cr, Mn, Fe, Ni, Co, T
In an Al-Sn bearing alloy containing one or more of i, V, and Zr in a single or total amount of more than 0.01% and less than 1.0%, and the remainder substantially consisting of Al, ．．
A structure in which more than 0.01% and less than 0.1% of Sb is added to disperse and precipitate Si particles in an Al matrix in the form of a sphere, an ellipse, or a shape with a rounded tip, which exists adjacent to the Sn-Pb alloy. An Al-Sn bearing alloy characterized by comprising: