JPS6136062B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aluminum alloy bearing, and more specifically, to an improvement of a tin-containing aluminum alloy bearing used as a bearing for an internal combustion engine. The above aluminum-based alloys containing tin are generally used as bearings by being pressure-welded to a backing steel plate, but in order to increase the adhesive strength between the bearing alloy and the backing steel plate, it is essential to anneal the alloy after pressure welding. Generally, this annealing is performed for a long time at a temperature below the temperature at which Al--Fe intermetallic compounds are formed. However, when tin-containing aluminum bearing alloys are exposed to high temperatures during the annealing process,
The drawback was that aluminum crystal grains and tin precipitates became coarse in the alloy structure, reducing the high-temperature hardness and fatigue strength of the bearing alloy. Therefore, in order to eliminate the above-mentioned drawbacks of tin-containing aluminum bearing alloys, bearing alloys containing additive elements are also used, such as 3.5 to 4.5% Sn.
−3.5~4.5%Si−0.7~1.3% Cu−Remaining Al, 4~8
%Sn-1~2%Si-0.1~2%Cu-0.1~1%Ni-
Remaining Al, 3-40% Sn - 0.1-5% Pb - 0.2-2% Cu
-0.1 to 3% Sb - 0.2 to 3% Si - 0.01 to 1% Ti - Remaining
Al, 15~30% Sn-0.5~2% Cu-remaining Al, and 1~
23%Sn-1.5~9%Pb-0.3~3%Cu-1~8%
Tin-containing aluminum-based bearing alloys (hereinafter referred to as multi-component bearing alloys) such as Si-residue Al were used. However, in recent years, internal combustion engines for automobiles have been required to be smaller and have higher output, and in addition, it has become necessary to install a blow-by gas reduction device to purify exhaust gas. It got even worse. In other words, as bearings in recent years have become smaller and used under higher loads and higher temperatures than before, conventional multi-component bearing alloys are prone to fatigue failure and abnormal wear, which is one of the causes of troubles in automobile internal combustion engines. I was getting used to it. Fatigue phenomena in metal materials are generally discovered when the material has been used for a long period of time, but in modern internal combustion engines, bearings can break due to fatigue even when high-load operation continues for a relatively short period of time. sometimes happened. This is because the lubricating oil in the internal combustion engine becomes hot during high-load operation, and for example, the temperature of the lubricating oil in the oil pan reaches 130 to 150°C. It is predicted that the bearing alloys will be sliding at considerably high temperatures, and as a result, the high-temperature hardness of conventional multi-component bearing alloys will rapidly decrease, and tin will melt or move, which is the cause of the decrease in fatigue strength. The inventor of the present application believes that this has become the case. Furthermore, in recent years for internal combustion engines, in order to reduce the cost of crankshafts, etc., there has been a trend to shift from conventional forged shafts to spheroidal graphite cast iron shafts, which are cheaper to process, and the shaft roughness has also tended to increase. There is also. However, on the machined surface of the spheroidal graphite cast iron shaft, there are many pits left behind by graphite particles that have been scraped off and fallen off during machining, and these edges cause abnormal wear on the bearing surface, leading to fatigue failure. Conventional bearings had the disadvantage of As a result of research into adding various additive elements to tin-containing aluminum alloys to improve their properties, the inventor of the present application proposed an alloy to which chromium and copper were added in JP-A-53-87917. In addition, an alloy containing chromium and copper, and lead and/or indium was proposed in JP-A-53-104463, and a tin-containing aluminum alloy was further added with silicon, manganese, antimony, titanium, nickel, iron, and zirconium. JP-A-55-11173 proposed an alloy that improves the hardness and wear resistance of the alloy by adding and dispersing and precipitating one or more of molybdenum, molybdenum, and cobalt. As a result of further progressing in the development of bearing alloys since the invention of the above-mentioned application, the present inventor has found that the weight percentage is 4 to 25.
% tin, 0.5 to 8% zinc, 1 to 7%
silicon, chromium, manganese, nickel, iron,
At least one element selected from the group consisting of zirconium, molybdenum, cobalt, tungsten, titanium, antimony, niobium, vanadium, cerium, barium and calcium and 0.1
It has been found that an aluminum-based alloy containing 2.0% to 2.0% of copper and/or magnesium, with the balance being substantially aluminum, can meet the demands placed on modern internal combustion engine bearings. In other words, by dispersing and precipitating silicon, chromium, etc., this aluminum alloy has higher hardness, wear resistance, and fatigue strength than conventional tin-containing aluminum alloys, and has the same conformability as conventional alloys. The aluminum matrix (hereinafter referred to as Al base) is further strengthened with zinc to further increase high-temperature hardness and fatigue strength. In the present invention, due to the synergistic effect of both the strengthening of the matrix of the aluminum alloy and the strengthening of the alloy by fine dispersions of silicon, chromium, etc., the bearing performance of the aluminum alloy is significantly improved compared to the case of a single action. There is. The alloy composition of the present invention will be explained below. Tin is an element that changes the properties of aluminum alloy to soft and provides lubrication performance and conformability suitable for bearings. In addition, conformability refers to the condition in which minute irregularities caused by the machining accuracy of the shaft, which is the mating material of the bearing, are filled up or flattened by the bearing material, so that both the bearing and the shaft are bonded together with a film of lubricating oil always interposed between them. Refers to the property of a bearing in which the surface of the bearing is ground down by the shaft during early use of the bearing to allow contact. When the tin content exceeds 25%, the conformability and lubricity improve, but the hardness decreases;
If it is less than %, the aluminum-based alloy becomes too hard as a bearing alloy, resulting in poor conformability. In order to ensure that the fatigue strength and high-temperature hardness of tin-containing aluminum alloys are sufficient for the performance required for bearings, it is important that tin be dispersed in the alloy as erect particles. However, in Sn-Al binary alloys, when the tin content exceeds 15%, the tin particles tend to become coarse (that is, it becomes difficult to divide the tin particles into fine particles).
It was thought that the hardness of the Sn-Al binary alloy would decrease. However, in the present invention, due to the effects of adding elements described later, even when up to 25% of these elements are added, there is no problem in practical use as a bearing for an internal combustion engine.
How to determine the amount of tin added in the range of 4 to 25% should be determined appropriately depending on the application, but in general, it is determined by the load applied to the bearing, that is, the amount of tin added via the piston of the internal combustion engine. When the explosive load to be applied is large, the tin content is preferably low, for example 5 to 10%, and when the load is small, the tin content is preferably high. A load applied to a bearing causes deformation of the bearing, and the bearing's resistance to this deformation is defined as the load capacity. Furthermore, from a different perspective than the load capacity, in applications where bearing seizure is a concern due to high loads and high speed rotation, the tin content may be set high, for example, 15 to 25%. Next, silicon, chromium, manganese, nickel, iron, zirconium, molybdenum, cobalt,
Elements of the group consisting of tungsten, titanium, antimony, niobium, vanadium, cerium, barium, and calcium are precipitated in the Al substrate, and the precipitated forms are single elements, intermetallic compounds between elements, and one or more of these elements. There are intermetallic compounds between aluminum and aluminum, but all forms have the effect of improving wear resistance. The hardness of these precipitates is extremely hard, reaching several 100 on the Vickers hardness scale, and these hard precipitates have a remarkable effect of improving wear resistance when the mating shaft is made of spherical graphite. Furthermore, if the precipitation form of the above-mentioned precipitates is such that it inhibits the growth of aluminum crystal grains at high temperatures during bearing manufacture and use, it promotes fine and uniform dispersion of tin particles. In this regard, each element such as silicon has a promoting effect to varying degrees, and this effect is particularly remarkable when the amount added is small. Content of silicon etc. mentioned above (2
If the total amount is less than 1%, the amount of precipitates will be small and the effect of improving wear resistance will not be exhibited;
%, the precipitates become too large. As a result, the mechanical strength, such as toughness, of the aluminum-containing alloy decreases, resulting in a decrease in fatigue strength and making rolling difficult. In addition, since the rolling property decreases, fine and uniform dispersion of tin particles becomes difficult. The reason for this will be explained later. The preferable content of the above-mentioned silicon, etc. is 1.5 to 4.0%. Incidentally, among the silicon, chromium, etc. mentioned above, chromium of 1% or less has special properties in the following points. Chromium increases the hardness of aluminum-based alloys, prevents them from softening at high temperatures, and prevents tin particles from becoming coarser at high temperatures due to annealing when joining the bearing backing metal to the bearing alloy. These effects are remarkable. First, regarding the issue of increasing hardness and preventing softening at high temperatures, if the chromium content is less than 0.1%, these effects, especially the effect of preventing high temperature softening, cannot be expected, and if it exceeds 1.0%, it will not cause softening. Since the Al-Cr intermetallic compound cannot be finely and uniformly dispersed and its effectiveness is reduced, the content should be reduced to 0.1 or more.
It is limited to 1.0%. Prevention of high temperature softening,
In other words, to elaborate further on the point that the high-temperature hardness of aluminum-based alloys does not decrease rapidly, some chromium forms a solid solution in the Al base, thereby causing solid solution strengthening (hardening) of the Al base itself. Furthermore, in order to increase the recrystallization temperature, the recrystallization softening temperature is shifted to the high temperature side. Furthermore, chromium-containing aluminum alloys have increased work hardening properties, and when they are cold-rolled one or more times, their hardness becomes significantly higher than when they are cast. Another effect of chromium is to increase the recrystallization temperature, which increases the temperature in the high temperature range to which internal combustion engine bearings are exposed (130-150°C at oil pan temperature).
℃), it is particularly effective in maintaining the temperature characteristics of the mechanical properties of chromium-containing aluminum alloys stably, and in particular, the temperature dependence of hardness is reduced by containing chromium, which is particularly effective in the high-temperature region. This results in improved bearing strength (fatigue resistance and load capacity). Part of the chromium dissolves in the Al base, and the rest exceeds the solid solubility limit and precipitates as an Al-Cr intermetallic compound, which exhibits a Witzkers hardness of approximately 370. . When such hard precipitates are finely and uniformly dispersed in the Al ground, they contribute to maintaining high-temperature hardness. The chromium content at which such precipitates are finely and uniformly dispersed is 0.1 to 1.0%. Next, the effect of chromium on inhibiting the coarsening of tin particles will be described. The coarsening of tin particles is a phenomenon that occurs when a tin-containing aluminum alloy is exposed to high temperatures, resulting in movement of aluminum grain boundaries and movement or melting of tin particles. In addition, the movement of aluminum crystal grains is related to the start of recrystallization and the movement of general crystal grains is unrelated to this, while the movement of tin particles is due to the movement of aluminum crystal grains. Various factors can be considered, such as the fact that tin particles in the vicinity sometimes move in an attempt to coalesce, or the tin particles deform in an attempt to assume a stable shape under high temperatures, and the factors that bring about the above phenomenon are complex. A portion of the chromium added to the aluminum-based alloy according to the present invention forms homogeneous precipitates as described above, which directly prevents movement of aluminum grain boundaries during annealing or use. In other words, it is thought that the coarsening of the tin particles is prevented, and indirectly, the movement of the tin particles, that is, the coarsening of the tin particles is prevented. This means that the fine shape of the tin particles, which has been refined through repeated cold rolling and annealing of the aluminum alloy, can be maintained in a shape close to that when the bearing is used, and the above-mentioned effects of the tin particles are also maintained. It will be done. The effect of preventing tin particles from coarsening is
Although it is observed even when the tin content is low, it is especially noticeable when the tin content is relatively high (approximately 10% or more).
Approximately 15 minutes when fine tin particles try to become coarser continuously
% or more, a particularly remarkable effect appears. Furthermore, the fact that the tin particles remain fine and exist in the Al ground is also considered to be effective from the point of view of preventing the elution phenomenon of the tin particles.
The reason is that the melting point of pure tin is 231°C, and the temperature of the sliding surface of an internal combustion engine bearing during sliding can exceed the melting point of tin, and the temperature to which the bearing is exposed is always far away from the melting point of tin. Therefore, the tin particles may easily undergo plastic flow due to the load received from the shaft, or in extreme cases, the tin particles may melt at the above temperature. However, if the tin particles maintain their fine shape, even if they melt or become extremely fluid, it is thought that it will not have such an adverse effect as to significantly reduce the hardness of the aluminum alloy as a whole. As described above, it is possible to prevent the high temperature hardness of the aluminum alloy from decreasing at high temperatures during annealing or use of the bearing, and thereby it is possible to improve the fatigue strength of the aluminum alloy. As detailed above
Since a small amount of chromium (0.1 to less than 1%) is very effective in improving bearing performance, the total amount of chromium (0.1 to less than 1%) and one or more other elements such as silicon should be 1% or more. By selecting these elements, it is possible to provide an aluminum-based alloy that has both high wear resistance and high fatigue strength as a bearing for modern internal combustion engines that use cast iron shafts such as spheroidal graphite cast iron. Zinc is an element that has a relatively high solid solubility limit in aluminum, and even within the range of addition to the aluminum-based alloy according to the present invention, most of the zinc is dissolved in aluminum. Generally, binary alloys made of aluminum containing a small amount of zinc are not put into practical use because of their low strength, so a ternary intermetallic compound of Al-Zn-X (X is the third element) was precipitated. It is well known that aluminum alloys are used. The present invention is different from conventional zinc-containing aluminum alloys in that the purpose of the present invention is to improve the fatigue strength, load capacity, and high-temperature hardness by strengthening the aluminum base by adding zinc. Zinc is generally referred to as a low melting point metal like tin, but it has a higher melting point than tin and is less compatible. Therefore, when using a zinc-containing aluminum alloy that does not contain tin, it is necessary to apply a lead-based overlay thereon to use it as a bearing. However, when zinc is added to an aluminum-based alloy containing tin, such as the aluminum-based alloy of the present invention, the above-mentioned properties are improved without impairing conformability, so that it can be used as a bearing without using an overlay. As mentioned above, precipitates are formed by silicon, etc. (including chromium), and chromium strengthens the Al base and increases the recrystallization temperature of aluminum alloys, making chromium particles uniform and fine even at high temperatures. As will be described later, it is a necessary premise for zinc to have the above-mentioned effects. Copper and/or magnesium are elements that further reduce the decrease in hardness at high temperatures than when Si or Cr is added alone, and also increase the absolute value of hardness, thereby increasing the fatigue strength of the bearing. will further improve. If the content of copper and/or magnesium (in the case of both, the total content) is less than 0.1%, the effect of preventing a decrease in high-temperature hardness and increasing the absolute value of hardness cannot be expected, while if it exceeds 2.0%, the alloy becomes hard. Excessive rolling impairs the rollability and also reduces the corrosion resistance against lubricating oil. The effect of preventing copper and/or magnesium high-temperature hardness reduction is due to silicon in the alloy,
This is caused by the coexistence of chromium and the like, and even if the alloy is heated to 200°C or higher, the high-temperature hardness does not decrease much. Note that this effect becomes even more pronounced due to the presence of zinc, and a decrease in high-temperature hardness is extremely unlikely to occur, resulting in a marked improvement in load capacity and fatigue strength. The content of copper and/or zinc is preferably 0.2 to 0.8%. In addition to the above composition, the aluminum alloy of the present invention further contains 0.1 to 10%, preferably at least one element selected from the group consisting of copper, bismuth, indium, thallium, and cadmium.
Those containing 0.5 to 5% (hereinafter referred to as this alloy)
(referred to as Al-Pb alloy). These elements such as lead, in coexistence with chromium, have the effect of improving the lubricity and wear resistance of the tin-containing aluminum alloy without reducing its fatigue strength. In other words, when elements such as lead are added to the Al-Sn binary alloy, these elements are alloyed into the tin particles, lowering the melting point of the tin particles.
As a result, tin particles tend to move and melt, resulting in the disadvantage that they grow into coarse tin particles. Therefore, when a conventional Al-Sn-Pb ternary alloy is used in a bearing, the alloy may partially melt and peel off during continuous high-load operation.
On the other hand, as in the present invention, particles of tin-lead or their alloys are made fine by adding silicon, chromium, etc. or by cold rolling so that they can be maintained even at high temperatures. In addition, the lubricity, wear resistance, and conformability of the Al-Pb alloy provided by tin, lead, or their alloys are further enhanced without causing the adverse effects of melting of tin, lead, or their alloy particles. It will be done. The aluminum-based alloy of the present invention is cold-rolled and annealed in the same manner as conventional alloys, and is then pressure-welded to a backing steel plate and used as a bearing in direct contact with a shaft. In addition, the reduction rate of cold rolling is 5 to 5 in one rolling.
In the range of 50%, the overall reduction is determined to obtain the desired thickness. After cold rolling, annealing is performed at 27 to 350°C in order to remove processing stress and to partially generate precipitates such as intermetallic compounds.
The fine dispersion of tin particles is made finer by dividing the tin particles during cold rolling, and in the process of repeating such cold rolling and annealing, the tin particles become extremely fine and uniformly penetrate into the Al ground. Becomes dispersed. It is thought that the zinc dissolved in the Al base during the cold rolling and annealing steps described above does not precipitate or disperse. When spread, tin and zinc both have the property of being soft, low-melting point metals, and because they tend to form a eutectic composition and are easily alloyed, this alloying should be avoided as much as possible, since tin and zinc contain a large amount of zinc in the aluminum. It is desirable that the Zn-containing tin particles form a solid solution, or that even if alloying occurs, the shape of the Zn-containing tin particles is extremely small. It should be noted that according to the present invention, the effect of zinc is realized for the first time because the tin particles are made fine by the cold rolling and annealing process. Also, in precipitates such as silicon,
0.1 to 1% chromium has a special effect in that an Al-Cr intermetallic compound is precipitated at the time of pressure welding to the backing steel plate, and prevents the coarsening of tin particles during annealing after pressure welding and during use of the bearing. . The average diameter of the tin particles in the bearing of the present invention is preferably within the range of 5 to 30 microns. Hereinafter, the properties of the present invention and conventional alloys and the effects of alloying elements will be explained in more detail with reference to Examples. In Table 1 below, sample numbers 1 to 20 represent alloys of examples of the present invention, in which aluminum ingots are melted in a gas furnace, and then Al-Cr master alloy, Al-Cr master alloy, Al- Cu master alloy and Al−
Mg master alloy is molten and added, and finally, one or more of tin, zinc, lead, indium, bismuth, thallium, and cadmium is added to the molten metal according to the target component, and after obtaining a molten metal with the desired composition, chlorine gas is added. was degassed by blowing and then cast into a mold. The obtained ingot was cold rolled at room temperature and then annealed (350
℃) was repeated to produce a sample with dimensions of 6 mm in thickness and 200 mm in width. The room temperature hardness and 200°C hardness of this sample were measured. Subsequently, the above sample was further cold rolled, then annealed and pressure bonded to the backing steel plate, followed by annealing at approximately 350°C for bonding, resulting in a half metal shape with a diameter of 52 mm and a width of 20 mm. . The shaft material was quenched S55C, and a dynamic load bearing fatigue test was conducted on the above half metal under the following conditions. Testing machine - Soda type dynamic load tester Sliding speed - 400 to 470m/min Lubricating oil type - SAE10W30 Lubrication method - Forced lubrication Lubricating oil temperature - 140±5℃ Lubricating oil pressure - 5Kg/cm ² Surface roughness of mating material (S55C) Hardness of mating material: Hv500 to 600 Bearing surface roughness: 1 to 3 μm Number of load cycles: 10 ⁷ times In addition, a wear test of the bearing was conducted under the following conditions. Testing machine - Ultra-high pressure seizure tester Sliding speed - 468 m/min Load - The load was gradually increased at a rate of 1 ton/45 minutes (equivalent to 100 Kg/cm ² /45 minutes), and the load was 500 Kg per 1 cm ² of the sample. The test was canceled. Lubricating oil type - SAE10W30 Lubrication method - Forced lubrication Lubricating oil temperature - 120 ± 5°C Surface roughness of mating material (S55C) - 1 μm Roughness of iron parts (excluding graphite parts) on the surface of mating material (spheroidal graphite cast iron) -1μm Hardness of mating material (S55C) - Hv500 to 600 Hardness of mating material (spheroidal graphite cast iron) - Hv200 to 300 In addition, the seizure load was measured by increasing the load applied to the bearing until seizure occurred. The test was carried out under the same conditions as the wear test. The above measurement results and sample composition are shown in the table below (see 1).
Table). In addition, sample numbers 21 to 23 in the table are alloys of comparative examples, and were manufactured by the same manufacturing method as that of the present invention.

[Table] First, the hardness in Table 1 will be explained. The Al-Zn-Pb alloy of sample number 23 (comparative example) has Hν at room temperature.
A relatively high hardness of 50 was obtained, and sample number 21
Comparing with and 22, it is clear that the inclusion of zinc changes the properties of the alloy to make it easier to work harden during cold rolling.Also, since 4% zinc is below the solid solubility limit of aluminum, this change is due to the properties of the Al base. It can also be seen that this is due to changes. Furthermore, when sample number 23 is compared with samples 21 and 22, the former has higher hardness at 200°C. The alloy consisting of Al, Sn, Zn, Si, etc. and copper/magnesium, which are essential components of the present invention, contains a large amount of soft tin (especially in spite of sample numbers 9 (20%) and 20 (25%)). First, it is noteworthy that the hardness is high.Next, the fatigue strength will be explained.The fatigue strength of the alloy of the present invention is superior to any of the comparative examples.Sample number of the comparative example containing tin Comparing 21 and 22 with the alloy of the present invention, it is concluded that the fatigue strength is improved due to the presence of zinc, silicon, etc. In the inventor's opinion, the zinc that strengthens the Al base improves the fatigue strength. It is effective in improving strength.In addition, the fatigue strength of samples containing large amounts of tin, indium, and thallium is not very high.Generally,
In particular, if the aluminum base is strengthened to have high high-temperature strength, the fatigue strength will improve.On the other hand, if a large amount of soft phases such as tin are present in the aluminum alloy, the fatigue strength will be lower, but 25% In sample numbers 10 and 20 containing tin, comparatively high fatigue strength was obtained due to the refinement of the tin particles and the strengthening of the aluminum base with zinc, as mentioned above. The bearing alloy of the present invention is characterized in that it has a high tin content and therefore has good conformability and lubricity as well as excellent fatigue strength. Next, the amount of wear will be explained. The amount of wear for S50C is not necessarily lower for all samples of the present invention than for Comparative Example Sample No. 22. This comparative example is considered to have a low amount of wear because the total content of tin and lead, which are rich in lubricity, is high. Among the alloys of the present invention, those containing lead or bismuth and those with a high tin content also have a relatively small amount of wear compared to S50C. This means that Al, Sn, Zn, Si, etc. and Cu/Mg
This means that the alloy composition of the present invention having lead, bismuth, and tin as essential components has a predominant content. In addition, since a low amount of wear was obtained in sample number 22, the fine and uniform dispersion of tin does not have as much of a decisive effect on the amount of wear as the fatigue strength. DC1
(Spheroidal graphite cast iron) The amount of wear of the present invention is lower than that of the comparative example. The amount of wear caused by DCI tends to be lower as the amount of Si, etc. and Pb, etc. added increases. The present inventor believes that wear resistance against DC1 is imparted to the aluminum-containing alloy firstly by hard precipitates such as Si and secondly by the lubricating action of Pb and the like. Finally, the seizure load will be explained. The seizure load for S50C is not necessarily higher for all of the samples of the present invention than for sample numbers 21 and 22, which contain the most tin among the comparative examples. The seizure load on steel materials is dominated by the contents of tin, bismuth, and lead, as well as wear resistance. However, the seizure load for DCI of the present invention is higher than that of the comparative example. In particular, the seizure load of sample numbers 13 and 15 containing lead etc. was high, and there is a tendency for the seizure load to increase as the amount of silicon etc. added increases. From the above facts, the inventor makes the following inference. (stomach)
The seizure resistance of aluminum alloys to steel is mainly controlled by the amount of hard precipitates such as silicon and the tin content.On the other hand, the seizure resistance to DCI (not seizing up to high loads) is , firstly by the amount of zinc, lead, etc., and secondly by the amount of precipitates such as silicon. (b) The seizure resistance against DCI increases as the tin content increases, but unless the tin particles are uniformly and finely dispersed, the resistance to DCI will not be high enough to allow the bearing to be used in an internal combustion engine. (c) The dispersion form of tin is not dominant in the seizure resistance of steel materials. (d) Even aluminum-containing alloys with excellent wear resistance do not necessarily have high seizure resistance. Wear resistance is mainly affected by the composition of the aluminum-containing alloy, and seizure resistance is mainly affected by its structure. As can be understood from the above examples, when the alloy of the present invention is comprehensively compared with conventional alloys in terms of high temperature hardness, fatigue strength, wear resistance, and seizure resistance, it is found that the alloy of the present invention has been used as a bearing for internal combustion engines in recent years. In particular, when the mating material is DCI, it is judged to have excellent performance, and it is concluded that improved bearing reliability and extended life are achieved.

Claims (1)

[Claims] 1. 4 to 25% tin, 0.5 to 8% zinc, 1 to 7% silicon, chromium, manganese, nickel, iron, zirconium, molybdenum, cobalt, tungsten, titanium, by weight fraction. , antimony, niobium, vanadium, cerium, barium, and calcium, and 0.1 to 2.0% of copper and/or magnesium, with the balance consisting essentially of aluminum. bearings. 2. The bearing according to claim 1, wherein the aluminum alloy is bonded to a back metal of a steel plate. 3. The bearing according to claim 2, wherein the aluminum alloy is in contact with a steel shaft or a cast iron shaft driven by a piston of an internal combustion engine via an oil film of lubricating oil. 4% by weight tin, 0.5 to 8% zinc, 1 to 7% silicon, chromium, manganese, nickel, iron, zirconium, molybdenum, cobalt, tungsten, titanium, antimony, niobium, vanadium, At least one element selected from the group consisting of cerium, barium and calcium, 0.1 to 2.0% copper and/or
or magnesium and 0.1 to 10% lead;
A bearing made of an aluminum alloy containing at least one element selected from the group consisting of bismuth, indium, thallium, and cadmium, with the remainder being substantially aluminum. 5. The bearing according to claim 4, wherein the aluminum alloy is bonded onto a back metal of a steel plate. 6. The bearing according to claim 5, wherein the aluminum alloy is in contact with a steel shaft or a cast iron shaft driven by a piston of an internal combustion engine via an oil film of lubricating oil.