JP2014196544A - Aluminum alloy for slide bearing and slide bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an Al-Sn-Si type slide bearing alloy which makes Fe contained as an impurity harmless and prevents a tool from forming a built-up edge during cutting of a slide bearing.SOLUTION: An aluminum alloy for slide bearings comprises 2-18% Sn, 2-7% Si, 0.05-1.5% Fe and remaining Al and unavoidable impurities, and Si particles and an Si-free Fe phase are dispersed in an Al matrix.

Description

The present invention relates to an aluminum alloy for a slide bearing, and more specifically to an aluminum alloy for an Al-Sn-Si based slide bearing and a slide bearing obtained by cutting the surface of the aluminum alloy in contact with the mating shaft. It is. In particular, the present invention has been completed by paying attention to the influence of Fe contained in an aluminum alloy on sliding characteristics.

Fe is treated as an impurity in industrial standards or specifications that define the composition of aluminum alloys for plain bearings, but Fe is used as a useful element in the following four patent documents.

Patent Document 1: Japanese Patent Application Laid-Open No. 62-37337 discloses a lubricating component having an Al-extruded cross-sectional area ratio of 0.006 to 0.040-5.0 to 10.0% by weight of a lipophilic component-0. The present invention relates to an extruded aluminum alloy comprising 2 to 5.0% by weight of a reinforcing component. The lubricating component is Pb, Sn, In, Sb and / or Bi, the hard component is Si, the lipophilic component is Zn, and the reinforcing component is Cu, Cr, Mg, Mn, Ni and / or Fe. is there. Fe is forcibly solid-solved in the Al matrix when the atomized powder is solidified to increase its strength.

Patent Document 2: Japanese Patent No. 3207863 relates to an Al-Sn-Si thermal spray alloy in which granular Si is dispersed in an Al matrix. The composition of this alloy is Al-12-60% Si-0.1-30% Sn, and as optional components 7.0% or less Cu, 5.0% or less Mg, 1.5% or less Fe and / or 8.0% or less of Ni is contained. Of the optional components, Fe forcibly dissolves in the Al matrix during spraying to increase the strength of the aluminum alloy.

The following two patent documents are directed to aluminum alloy rolled sheets.
Patent Document 3: Japanese Patent Publication No. Sho 62-42983 proposed by the present applicant is added to the alloy by annealing at 350 to 550 ° C. before pressing the Al—Sn bearing alloy rolled plate to the backing metal plate. It has been proposed to coarsen and agglomerate the formed Fe, Si and the like. The composition, structure and structure of the aluminum alloy are as follows. Composition-(a) 1-35 wt% (hereinafter the same) Sn, (b) 0.5-11% Mn, Fe, Mo, Ni, Zr, Co, Ti, Sb, Cr and / or Nb, ( c) 0.1-10% Pb, Cd, In, Tl and / or Bi, (d) 0.1-2% Cu and / or Mg. Tissue-Bulk particles composed of the element (b) or containing the element (b) are formed, and there are 5 or more particles having a major axis size of 5 to 40 μm per 3.56 × 10 ⁻² mm ² . Also, the bearing structure-overlay is not used, and the lump particles on the surface of the sliding bearing ensure the familiarity with the mating shaft.
In this patent document, Fe is present in an amount of 0.5% or more, and if it is annealed before pressure welding, it becomes agglomerated particles and contributes to conformability. However, a small amount of Fe exists as fine intermetallic compound particles, improving characteristics. It is explained that it does not contribute to.

Patent Document 4: Japanese Patent No. 3857503 discloses “In an aluminum-based bearing alloy that is rolled into a plate shape and pressed against a back metal after casting, 3 to 40 mass% of Sn, 0.5 to 7 mass% of Si, 0.05-2 mass% Fe, 0.1-5 mass% Cu, the balance consists of Al and unavoidable impurities, and Al—Si—Fe ternary intermetallic compound and Si particles are used as hard particles. Including, and by rapidly cooling at the time of casting and controlling the initial size of the intermetallic compound to 40 to 55 μm, among the hard particles, the hard particles made of the intermetallic compound are on the bearing surface, The present invention relates to an aluminum-based bearing alloy having a maximum diameter of 1 to 20 μm and 6 to 100 pieces per 1 mm ² .
Patent Document 4 shows that Al-Si-Fe ternary intermetallic compound particles have better crack resistance when lapping the counterpart shaft than Si particles alone, and part of the added Si is in the Al matrix. It is described that it is dissolved or precipitated as fine particles to improve fatigue resistance, wear resistance, and seizure resistance.

Patent Document 1: Japanese Patent Laid-Open No. 62-37337 Patent Document 2: Japanese Patent No. 3207863 Patent Document 3: Japanese Patent Publication No. 62-42983 Patent Document 4: Japanese Patent No. 3857503 Patent Document 5: Japanese Patent Laid-Open No. 7 -259860

Non-Patent Document 1: Tribology Conference Proceedings of Japan Tribology Society (Tokyo 1998-5)
"Micro groove plain bearing" 3B8

Patent Documents 3 and 4 use the additive Fe of the aluminum alloy to scrape the roughness of the surface of the mating shaft. However, in the conventional Al—Sn—Si type plain bearing alloy that does not add Fe for such a purpose, Fe does not perform any useful function.
The present inventors considered this cause as follows. It can be found that the Al side of the Fe-Al binary phase diagram has no solid solubility of Fe, and that Fe always forms an Al-Al ₃ Fe eutectic. The impurity Fe forming the eutectic impairs the ductility of the aluminum alloy and makes the sliding characteristics poor. Further, even if Fe is forcibly dissolved in an Al matrix, Fe is conventionally treated as an impurity element in order to similarly impair ductility. In view of such a background, an object of the present invention is to suppress the harmful action of Fe as an impurity in an Al—Sn—Si based plain bearing alloy.

Furthermore, the present inventors conducted earnest research on a rolled aluminum alloy sheet for bearings that can utilize Fe as an effective element, and obtained the following knowledge.
(1) Developed by the present applicant, Patent Document 5: JP-A-7-259860 and Non-Patent Document 1
; Japanese Tribology Society Tribology Conference Preliminary Proceedings (Tokyo 1998-5) Micro-Groove Slide Bearings published in 3B8 are formed by a boring machine equipped with a sintered diamond tool (Non-Patent Documents 1 and 4). . As can be seen from FIG. 1 that cites FIG. 9 showing the actual measurement value of the micro-groove shape shown in Non-Patent Document 1, the groove has an arc shape. However, because the cutting edge is formed on the cutting tool, the target height cannot be obtained, and fine roughness occurs on the surface (Fig. 2).
(2) If the amount of Fe in the Al-Sn-Si plain bearing alloy is large, formation of the constituent cutting edge is suppressed and the cutting shape of the microgroove is stabilized.
(3) Additive Fe reduces cutting roughness even in normal bearings without microgrooves
To do.

Conventionally, Patent Documents 3 and 4 in which Fe was used as an effective element were considered as follows.
In Patent Document 3, it is necessary to add 0.5% or more of Si, Fe or the like in order to form massive particles. Agglomeration is based on Ostwald growth and Si is suitable for agglomeration, but Fe requires a very long annealing at high temperature because of its slow diffusion rate. Further, Patent Document 3 does not disclose detoxification of Fe having an impurity level of less than 0.5% and further effective utilization.

Since Patent Document 4 proposes to use an Al-Si-Fe-based compound for lapping the mating shaft instead of the Si particle alone, the Si particle alone exerts the wrapping action and at the same time the harmful action of the impurity Fe. It is not a technology to remove. Furthermore, since the Al—Si—Fe-based intermetallic compound is harder than Si and has a shape with sharp corners, there is a possibility that the cutting tool may be worn. Therefore, although patent document 4 can be said to utilize effectively the conventional impurity level of 0.05% or more, there exists a possibility of scuffing a cutting tool.

Since the bulk Si particle-dispersed Al—Sn—Si-based slide bearing is mounted on a part of a commercial vehicle, the applicant suppresses the harmful effect of Fe as an impurity on such a slide bearing alloy and at the same time Si The following knowledge was obtained by conducting research for the purpose of providing an aluminum alloy for bearings capable of obtaining the action of massive particles.
(4) It is desirable to disperse Si bulk particles in an aluminum material having excellent ductility.
(5) The Si massive particles are brazed with a cutting tool, and an aluminum alloy adheres to the formed ridges to form a constituent cutting edge. This tendency becomes more prominent as the Si particle size is larger and / or the corners are sharper. In addition, Al itself has a high affinity with the cutting tool material, and it is a problem that adhesion occurs and it is easy to form the constituent cutting edge. , Can be suppressed.

The first of the present invention completed based on the above findings (1) to (3) is a mass percentage of 1 to 20% Sn, 0.5 to 12% Si, and 0.05 to 1.5%. An aluminum alloy for a slide bearing, which contains Fe and the balance of Al and inevitable impurities, wherein an Fe phase not containing Si particles and Si is dispersed in an Al matrix. The present invention will be described in detail below.

In the aluminum alloy for sliding bearings of the present invention (hereinafter abbreviated as “aluminum alloy”), Sn is an element imparting lubricity, and if the content (mass%, the same applies hereinafter) is less than 1%, lubrication is achieved. On the other hand, if it exceeds 20%, mechanical properties become poor due to a decrease in strength and melting point due to the soft Sn phase, resulting in deterioration of wear resistance and the like. The Sn content is preferably 2 to 18%.

In the aluminum alloy of the present invention, Si is crystallized as an Al—Si eutectic at the time of casting, and then is finely dispersed in the aluminum matrix as Si particles by rolling of the cast plate to impart wear resistance. That is, Si particles do not need to be agglomerated by the method of Patent Document 1, and particles that are refined by rolling contribute to wear resistance. The size of the Si particles is not particularly limited, but the average particle size is preferably 2 μm or more and the maximum particle size is preferably 12 μm or less. A preferable Si content is 2 to 7%.

The concentration of each element was EPMA color mapped on a rolled sheet having a composition of Al-12% Sn-3% Si-2% Fe produced by a method for controlling cooling during casting described later. A photograph obtained by binarizing the color mapping into black and white is shown in FIG. The elements arranged in 3 columns and 3 rows in FIG. 3 are as follows. Although 2% Fe in the above composition exceeds the upper limit of claim 1, it is used for the explanation because the color mapping is clear. Therefore, the following description is applicable also about the aluminum alloy of the amount of Fe within the scope of the present invention.

4, 5 and 6 are sketch diagrams of the element concentration patterns shown in Table 1. FIG. 4 to 6, 20 is an Al matrix, 21 is an Fe phase, and 22 is a Si phase. These figures will be described with the original color mapping information added. In FIG. 4, the Al concentration of the Al matrix 20 is the highest red, and in FIG. 5, the Fe concentration of the Fe phase 21 is from the highest red to a lower concentration. It is distributed up to blue and extends along the grain boundaries of the Al matrix. Al taken in the Fe phase 21 in FIG. 5 is distributed from yellow to blue. The same pattern as the Si phase 22 shown in FIG. 6 is also observed in FIG. 4, and it can be seen from this pattern that the Si phase 22 is an Al—Si eutectic. Since the patterns in FIGS. 5 and 6 do not match, the crystallization of the Al—Si eutectic and the Fe phase 22 occurs at different positions.

FIG. 7 is a graph schematically showing changes in the Fe concentration and Al concentration of 21a in the Fe phase of FIG. 5 in the horizontal direction of the paper. 4 to 7 and the assumed Al-Fe pseudo binary system phase diagram of the Al-Sn-Si-Fe-based aluminum alloy, the composition of the aluminum alloy of the present invention is closer to the Al-rich side than the Al-Fe eutectic point. Because of the hypoeutectic composition, the Fe phase extends along the grain boundary after Al crystal solidification, and since Fe takes in Sn, Al, etc. after aluminum crystallizes, as shown in FIG. Concentration profiles are formed.

In the present invention, the Fe phase is a region where Fe is detected outside the region where Al concentration is highest (20 shown in FIGS. 4 to 6) in EPMA analysis. As shown in FIG. 7, the Fe phase incorporating Al will be described based on the Fe—Al binary phase diagram. The Fe side 21 ′ is not on the Fe rich side with about 14 wt% Al as a boundary. It is an ordered solid solution, and the Al-rich side is an ordered solid solution. Furthermore, an Fe ₃ Al ordered lattice is formed at 600 ° C. or lower. That is, the basic form of the Fe phase is a solid solution. Since the Al side 21 "has no solid solubility of Fe in Al, precipitation of Fe occurs. The center of the Fe phase has a composition close to that of pure iron having a low Al concentration. It is thought that the detoxification is caused by the Fe phase having the crystal structure as described above, so that the Fe content of 1.5% exceeding the conventional Fe impurity level does not deteriorate the bearing performance. Even when the amount is 0.05% or more, which is the conventional impurity level, it is possible to achieve better seizure resistance than the conventional aluminum alloy, provided that the Fe content exceeds 1.5%. It becomes difficult to roll the aluminum plate.

When the molten aluminum alloy having the composition of the present invention is poured into a continuous casting mold to form a continuous casting plate having a thickness of 3 to 20 mm, the temperature of the cast plate solidified from the molten metal temperature in the mold is 850 to 300. By cooling the temperature range of ° C. at a rate of 2000 to 5000 ° C./min, an Fe phase not containing Si can be formed. Moreover, the amount of Al and additive elements taken up can be increased by slowing the cooling rate.

A slide bearing can be formed by press-contacting the aluminum alloy of the present invention with a low carbon steel such as SPCC or SPCH. In such a sliding bearing, Fe is dispersed in the aluminum matrix as an Fe phase to stabilize cutting. When an aluminum alloy is cut with a cutting tool, aluminum adheres to the surface of the cutting tool to form a constituent cutting edge, so that the cutting roughness of the slide bearing surface becomes rough. Regarding the hardness of the Fe phase and the like, cutting tools such as high-speed steel and diamond tools (hardness Hv 1500 or more)> Si particles (hardness of about Hv 1000)> Fe-Al intermetallic compound (hardness Hv 700 or more)> Fe phase ( Since there is a relationship of pure iron (Hv200)) to Al and an Fe phase (Hv400) incorporating an additive element> Al alloy phase (Hv = 30 to 90), the Fe phase can scrape the aluminum alloy of the constituent blade edge. On the other hand, since there is little difference with the hardness of cutting tool material, Si particle | grains etc. have a possibility of scuffing a cutting tool. As a result, since the roughened tool scrapes the aluminum alloy, the cutting roughness of the slide bearing becomes rough.
When the additive element is Cu or Cr, the Fe phase becomes a Fe—Cu—Cr solid solution phase in which Al, Cu, and Cr are dissolved in the Fe crystal, and this phase is Fe ₃ Al, Fe—Al—Si. Although the hardness is lower than that of the intermetallic compound, the toughness and hardness are increased by the addition of Cu and Cr. From these physical properties, the Fe—Cu—Cr phase is particularly excellent in the effect of removing the constituent cutting edge by cutting Al. Specifically, since Al chips can be finely discharged, cutting surface defects due to continuous chips can be avoided. If a hard phase exists on the surface to be cut of the aluminum alloy, voids and defects are generated when the cutting tool breaks the hard phase. However, since the Fe—Cu—Cr phase is excellent in toughness, vacancies and defects can be prevented.

FIG. 8 shows a state in which an aluminum alloy having a composition of Al-3 to 15% Sn-2 to 7% Si-0.1 to 5% Fe was cast under the conditions described below, and the obtained cast plate was rolled. From the graph showing the surface roughness (RzJIS), Ra, and Rmax when cutting the surface of the plate (as roll) with a (lathe) tool at a cutting condition of 1 m / s, the larger the amount of Fe, the more the tool and cutting conditions. It can be seen that Rmax and RzJIS are small despite being constant. When the surface of the tool edge after cutting was visually observed, it was also found that the greater the amount of Fe, the fewer the constituent edge. From these experimental results, the larger the amount of Fe, the more preferably 0.3% or more, the material to be cut off scrapes the constituent cutting edge, and the roughness of the material to be cut decreases. The conventional cutting edge formation is the reason why the desired roughness cannot be obtained, but this can be solved to stabilize the cutting.

In the aluminum alloy plain bearing of the present invention, the surface in contact with the mating shaft is preferably machined in the range of RzJIS = 0.5-5 μm, Ra = 0.1-1.8 μm, Rmax = 0.5-6 μm. ing.

  Furthermore, the aluminum alloy according to the present invention can contain at least one of Cr (0.5% or less) and Cu (3% or less) (hereinafter referred to as “additive element”) by mass%. Of these additive elements, Cr forms an Al—Cr intermetallic compound and improves the strength of the aluminum matrix. Further, the additive element is taken into the Fe phase, and the effect of removing the constituent edge is enhanced by increasing the hardness of the Fe phase. If the Cr content exceeds 0.5%, it is segregated in the aluminum matrix, resulting in a decrease in rollability and the like.

Among the additive elements, Cu reinforces the matrix of the aluminum alloy and improves heat resistance.
Cu is also taken into the Fe phase and increases its hardness. However, if the amount of Cu exceeds 3%, it is not preferable because cracks occur during rolling due to a decrease in rolling properties.

Furthermore, the aluminum alloy according to the present invention includes at least one of Mg, Ag, and Zn in a total amount of 8% by mass or less, and at least one of Zr, Mn, V, Sc, Li, and Ni in a total amount of 0.5%. It can contain the mass% or less. Mg, Ag, and Zn cause solid solution strengthening. However, if the content exceeds 8% by mass in total, the performance deteriorates due to the formation of intermetallic compounds, precipitation, and toughness reduction due to crystallization of added elements, which is not preferable. In the aluminum alloy according to the present invention, at least one of Zr, Mn, V, Sc, Li, and Ni can be 0.5% by mass or less in total. Zr, Mn, V, Sc, Li, and Ni cause precipitation strengthening, but if the total amount exceeds 0.5% by mass, the effect of improving the strength cannot be obtained due to coarsening and segregation of the precipitated particles, which is not preferable. These Mg, Ag, Zn, Zr, Mn, V, Sc, Li, and Ni are hereinafter referred to as “additional elements”. Among the additional elements, Mn, Ni, Zr, and V are normal Fe alloy elements, but since the content is small, only a trace amount or less is taken into the Fe phase.

In addition to the basic components and additive elements described above, a small amount of impurities such as Pb, In, Bi, which are inevitably brought about from bullion and scrap materials. Ti and B are usually finer agents for Al crystal grains. However, in the aluminum alloy of the present invention, since the fine crystal grains are not related to Fe phase formation, a total amount of 0.5% or less is allowed as an impurity. The

The second aluminum alloy for plain bearings of the present invention contains, by mass, 1 to 20% Sn, 0.5 to 12% Si, and 0.05 to 1.5% Fe, optionally added. In a sliding bearing aluminum alloy containing an element and / or an additional element, the balance being Al and inevitable impurities, Si particles and Fe phase are dispersed in an Al matrix, and the Si particles having a major axis dimension of 5 to 40 μm Are 5 or more per 3.56 × 10 ⁻² mm ² .

The second aluminum alloy of the present invention is subjected to annealing before press contact with the back metal disclosed in Patent Document 3 at 300 to 550 ° C., and by coarsening the Si particles, the surface of the mating shaft, in particular, the surface of the casting shaft is uneven. Can be smoothed. Similarly, Si particles can be coarsened by annealing at 300 to 550 ° C. in the same manner for solid bearings that are not in pressure contact with the back metal. The Fe phase is as described in paragraphs 0018 to 0021. Further, the second aluminum alloy of the present invention can contain the above-mentioned additive elements and / or additional elements. The action of these elements is as described in paragraphs 0026 to 0028.

In another embodiment of the second aluminum alloy of the present invention, the coarse Si particles have an equivalent circle diameter of 2 to 15 μm, and the number of Si particles having an equivalent circle diameter of 4 μm or more is 20% or more. And the characteristics are further improved.

In the aluminum alloy according to the first aspect of the present invention, Fe is rendered harmless by allowing Fe to exist as an Fe phase in the grain boundary of the aluminum crystal. Properties are improved. Moreover, even an aluminum alloy containing 0.3% or more of Fe far exceeding the conventional impurity level (Claim 2) has good sliding characteristics. Al taken in the Fe phase (Claim 3) improves the sliding characteristics by strengthening the Fe phase.

The additive element contained in the aluminum alloy according to claim 4 enhances the bearing performance, and the additive element partially incorporated into the Fe phase (claim 5) increases the hardness of the Fe phase and increases the effect of removing the constituent edge. . The additional element (Claim 6) exclusively improves the sliding properties of aluminum.

In addition to the effect achieved by Patent Document 1 in which massive Si particles scrape off and smooth the surface of the mating shaft, the aluminum alloy according to claim 7 of the present application is made Fe harmless and further has a component cutting edge removal effect. .

The slide bearing using the first or second aluminum alloy of the present invention (Claims 9 and 10) exhibits the basic characteristics of a slide bearing with Sn and Si, and improves the sliding characteristics with an additive element. The Fe phase stabilizes the surface roughness of the bearing when the bearing is cut, and the targeted surface roughness can be stably obtained. Further, in the micro groove bearing made of the aluminum alloy of the present invention, the lubricating oil flows ideally cleanly in the groove, so that the bearing performance is improved and seizure and wear are less likely to occur. In addition to such an improvement in bearing performance, since the constituent cutting edges are suppressed, it is possible to suppress a decrease in efficiency due to interruption of the operation during the cutting and polishing of the tool cutting edge.
Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 (first invention)
An aluminum alloy having the composition shown in Table 1 was continuously cast on a plate having a thickness of 15 mm while controlling the cooling rate (paragraph number 0022). However, Comparative Examples 9 to 12 were cast in the above 850 to 300 ° C. temperature range at a normal slow cooling rate without controlling the cooling rate. After cold rolling to the obtained cast thin plate, the aluminum alloy was pressure-bonded to the back metal (SPCC steel plate).

Using these bimetallic materials, bearings were processed and performance tests were conducted under the following conditions.
Fatigue resistance test (A) Test machine: Reciprocating load test machine (B) Rotational speed: 2000 to 3000 r. p. m
(C) Test temperature (bearing back surface temperature): 160 ° C
(D) Counterpart material: S55C induction hardening (e) Lubricating oil: CF-4 10W-30
Seizure resistance test (A) Test machine: Static load test machine (B) Rotational speed: 1300 to 8000 r. p. m
(C) Test temperature (oil supply temperature): 160 to 180 ° C
(2) Load: 5MP gradually increasing (e) Counterpart material: S55C induction hardening (f) Lubricating oil: SN 0W-20
Abrasion resistance test (A) Test machine: Load wear test machine (B) Rotational speed: 0 to 1000 r. p. m
(C) Test temperature (oil supply temperature): 50 to 80 ° C
(D) Counterpart material: S55C induction hardening (e) Lubricating oil: SN 0W-20
The test results are shown in Table 2.

Remarks:
In Table 1 and Table 3 described later, “number” is the number of Si particles having a major axis dimension of 5 to 40 μm in an area per 3.56 × 10 ⁻² mm ² . The unit of “average particle diameter” is μm. The unit of “fatigue surface pressure” and “seizure surface pressure” is MPa. The unit of wear amount is μm.

The No. 2 of the example and the comparative example No. 10 have almost the same Si and Sn composition, but the bearing performance of the former is superior to that of the latter although the amount of Fe is large. Similar relationships are observed for No. 1 of the example and No. 9 of the comparative example, and also for No. 5 of the example and No. 11 of the comparative example. In addition, although other examples contain a high concentration of Fe, the bearing performance is good.

Example 2 (second invention)

The aluminum alloy having the composition shown in Table 3 was cast and rolled in the same manner as in Example 1, and annealed at 530 ° C. for 6 hours. After the annealing, the aluminum alloy was further pressure-bonded to the back metal (SPCC steel plate) during the rolling. The results of measuring the bearing performance in the same manner as in Example 1 are shown in Table 3, and the results of a cutting test using a cutting tool under the condition of 1 m / sec are shown in Table 4. In Table 3, “dimension” is the equivalent circle diameter (μm), and “ratio” is the ratio of the number of particles having an equivalent circle diameter of 4 μm or more to the whole. Incidentally, the requirement of claim 7 was satisfied that the number of Si particles in Table 3 was 5 or more per 3.56 × 10 ⁻² mm ² .

Although the embodiment of the present invention contains a high concentration of Fe, the bearing performance is excellent. Furthermore, the system can obtain a high finishing roughness.

The aluminum alloy of the present invention can be used for half metal bearings, bushings, thrust washers and the like.

It is the surface profile of micro-gove. It is the surface profile of the micro groove cut with the tool in which the constituent cutting edge was formed. It is the photograph which carried out the black-and-white binarization of the photograph which carried out the EPMA color mapping of the aluminum alloy which has a composition of Al-6% Sn-3% Si-2% Fe. It is a sketch figure of the pattern which shows Al concentration among the photographs of FIG. It is a sketch figure of the pattern which shows Fe density | concentration among the photographs of FIG. It is a sketch figure of the pattern which shows Si density | concentration among the photographs of FIG. It is a schematic diagram of the Al and Fe concentration profile of the Fe phase. It is a graph which shows Fe content, surface roughness (RzJIS), Ra, Rmax of Al-3-15% Sn-2-7% Si-0.2-5% Fe-type aluminum alloy.

20-Al matrix 21-Fe phase 22-Si phase

Claims (10)

In an aluminum alloy for slide bearings containing 1 to 20% Sn, 0.5 to 12% Si, and 0.05 to 1.5% Fe in mass percentage, the balance being Al and inevitable impurities An aluminum alloy for a sliding bearing, wherein an Si phase and an Fe phase not containing Si are dispersed in an Al matrix. The aluminum alloy for a slide bearing according to claim 1, wherein the Fe content is 0.3% or more. 3. The dispersed phase of the Fe phase takes in Al from the Al matrix, and the concentration of Al is highest at the interface between the dispersed phase and the Al matrix and decreases toward the inside. Aluminum alloy for sliding bearings as described. Further, at least one kind of Cr of 0.5% or less and 3% or less of Cu (hereinafter referred to as “additive element”) is contained by mass percentage. Aluminum alloy for sliding bearings as described. The additive element is taken into each dispersed phase of the Fe phase from the Al matrix, and the concentration of the additive element is highest at the interface between the dispersed phase and the Al matrix and decreases toward the inside. 4. Aluminum alloy for slide bearings according to 4. At least one of Mg, Ag, and Zn is 8% by mass or less in total amount, at least one of Zr, Mn, V, Sc, Li, and Ni is 0.5% by mass or less in total amount, and as an inevitable impurity The aluminum alloy for plain bearings according to any one of claims 1 to 5, comprising Ti and B in a total amount of 0.5% by mass or less. The aluminum alloy for a sliding bearing according to any one of claims 1 to 6, wherein five or more Si particles having a major axis dimension of 5 to 40 µm are present per 3.56 × 10 ^-2 mm ² . The aluminum alloy for a slide bearing according to claim 7, wherein the equivalent circle diameter of the Si particles is 2 to 15 µm, and the number of Si particles having an equivalent circle diameter of 4 µm or more is 20% or more. 9. A slide bearing comprising a clad material in which the aluminum alloy for a slide bearing according to any one of claims 1 to 8 and a low carbon steel such as SPCC or SPHC are pressed by cold rolling. The plain bearing according to claim 9, wherein a surface in contact with the mating shaft is cut.

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