JP5981097B2 - Al alloy bearing and manufacturing method of Al alloy bearing - Google Patents

Description

The present invention relates to an Al alloy bearing provided with an Al-based bearing alloy layer containing Sn and a method for manufacturing the Al alloy bearing .

Soft metals such as white metal and Al—Sn alloy are used for bearings of internal combustion engines.
Further, for example, in Patent Document 1, in order to improve the fatigue strength of a soft metal, the soft metal is remelted by laser irradiation to eliminate casting defects in the soft metal, and further, the soft metal that is remelted is used. It is disclosed that metal is cooled rapidly to suppress coarsening of the structure and form a homogeneous microstructure.

JP-A-9-10918

  For example, in an Al alloy bearing including an Al-based bearing alloy layer containing Sn, if an attempt is made to further improve the performance of the internal combustion engine, the Al alloy bearing will be exposed to a more severe situation. In this case, it is considered that the above-described method for improving the fatigue strength is insufficient in improving the non-seizure property of the Al alloy bearing.

This invention is made | formed in view of the situation mentioned above, The objective is provided with the Al base bearing alloy layer containing Sn, and providing the manufacturing method of Al alloy bearing which is excellent in non-seizure property, and Al alloy bearing. is there.

An Al alloy bearing according to an embodiment of the present invention includes an Al-based bearing alloy layer on a base material, and the Al-based bearing alloy layer contains Al and 30 to 70% by mass of Sn on the sliding surface side. It has a surface layer containing. The surface layer has an Al phase composed of Al and a Sn phase composed of Sn, the average value of the interphase distance between adjacent Sn phases is 10 μm or less, and the average value of the aspect ratio of the Sn phase is 4 Ri der above, is characterized in that the long axis of the Sn phase has a direction intersecting the sliding surface.

The base material is a component for providing an Al-based bearing alloy layer. For example, when an intermediate layer is provided between the back metal layer and the Al-based bearing alloy layer, the back metal layer and the intermediate layer are base materials. Further, when the Al-based bearing alloy layer is provided on the back metal layer, the back metal layer is the base material.
When the intermediate layer is provided, the intermediate layer is formed of pure Al or an Al alloy. Examples of the Al alloy include JIS 1000-3000 Al alloy.

  The Al-based bearing alloy layer has a structure in which a plurality of layers containing Al and Sn are stacked, has a surface layer on the sliding surface side, and an anti-surface layer on the base material side. The substrate side of the anti-surface layer is in contact with the intermediate layer when the intermediate layer is provided on the substrate, and is in contact with the back metal layer when the intermediate layer is not provided on the substrate. The Al-based bearing alloy layer may have one or more layers mainly composed of Al between the surface layer and the anti-surface layer.

  The surface layer contains Al and 30 to 70% by mass of Sn, and has an Al phase made of Al and an Sn phase made of Sn. The Al phase is an aggregate of Al atoms, and the Sn phase is an aggregate of Sn atoms. In addition, other atoms may be dissolved in these phases. The surface layer may contain a phase composed of other atoms in addition to those phases.

In the surface layer, the average value of the aspect ratio of the Sn phase is adjusted to 4 or more, more preferably 6 or more. As shown in FIG. 2, the aspect ratio of the Sn phase distributed in the surface layer is the length L ₁ of the major axis of the ellipse when the smallest ellipse in contact with the outer edge of the Sn phase 1 is drawn, and the ellipse of the minor axis of the sought as a value _L 1 / _{L 2} of the ratio of the length _{L 2.} In FIG. 2, the matrix 2 is shown, and the center of gravity of the Sn phase 1 used for the description to be described later is shown as G.

The average aspect ratio of the Sn phase is obtained as follows. First, the total area of the Sn phase in the measurement visual field and the aspect ratio of each Sn phase are determined from the images of the respective Sn phases distributed in the measurement visual field.
Next, the area of the Sn phase is accumulated in order from the Sn phase having the largest aspect ratio, and the Sn phase having a large aspect ratio until the accumulated area reaches 50% of the total area of the Sn phase is averaged for the aspect ratio. Is the target of the Sn phase for which And the average value of the aspect ratio of Sn phase has calculated | required the average value from the aspect ratio of Sn phase made into this object.

The relationship of the aspect ratio of the Sn phase distributed in the surface layer will be described with reference to FIG. FIG. 3 schematically shows Sn phases 3 and 4 having different aspect ratios and matrices 5 and 6 made of, for example, an Al phase. And FIGS. 3 (a) is greater Sn phase 3 aspect ratio, showing an example of the cross-sectional shape of the matrix 5, showing the area of the Sn phase 3 of the sliding surface 28 as S _1. FIG. 3B shows an example of a cross-sectional shape of the Sn phase 4 having a smaller aspect ratio than the Sn phase 3 and the matrix 6, and the area of the Sn phase 4 on the sliding surface 28 is represented by S _2. As shown.
As shown in FIG. 3, the larger the average value of the Sn phase aspect ratio is, the larger the number of elongated Sn phases 3 is. Further, when the cross-sectional area _{S 12} of the cross-sectional area _{S 11} and Sn phase 4 of the Sn phase 3 is the same, the size of the area of the sliding surface of the Sn phase 3 and 4 in the sliding surface 28 _S 1 <S ₂ .

According to the above configuration, the load of the mating member is received by the Al phase, Sn phase, etc. that form the surface layer. In FIG. 3, showing the load of the mating member at F _1.
Here, since Sn has a lower melting point than Al, the Sn phase softens more easily than the Al phase due to frictional heat generated when the counterpart member slides on the sliding surface of the surface layer, and plastically flows. It becomes easy. Therefore, the Al phase receiving the load from the mating member generates pressure in the direction of pushing the softened Sn phase onto the sliding surface. Incidentally, the pressure to push the Sn phase 3 shown in FIG. 3 (a) at _{P 1,} schematically showing a pressure pushing the Sn phase 4 shown in FIG. 3 (b) at _{P 2.}

As the average value of the aspect ratio of the Sn phase distributed in the surface layer is larger, specifically, when the average value of the aspect ratio is 4 or more, the Sn phase is slid as described above. Since the area on the surface is small, it is easily pushed out from the inside of the surface layer onto the sliding surface by the pressure from the Al phase. In this case, in FIG. 3, the pressure at which the Al phase pushes out the Sn phase is P ₁ > P ₂ .

Furthermore, since the Sn phase extruded onto the sliding surface is in a state of being softened and easily plastically flowing, it is likely to spread on the sliding surface. In other words, the Al phase distributed on the sliding surface is easily covered with the Sn phase extruded on the sliding surface. As a result, the counterpart member is less likely to directly hit the Al phase, which is harder than the Sn phase. Thereby, the non-seizure property of the surface layer can be improved, and the non-seizure property of the Al alloy bearing can be improved.
Furthermore, when the average aspect ratio of the Sn phase is 6 or more in the surface layer, the Al phase distributed on the sliding surface is more easily covered with the Sn phase extruded onto the sliding surface. The non-seizure effect is more easily obtained.

In the surface layer, the average value of the interphase distance between adjacent Sn phases is adjusted to 10 μm or less, more preferably 7 μm or less. The interphase distance between adjacent Sn phases is a distance between the center of gravity of a certain Sn phase and the center of gravity of the Sn phase adjacent to the Sn phase, so-called distance between the centers of gravity. 2 shows an example of a phase distance Sn phase adjacent as L _3.

When the average value of the interphase distance between adjacent Sn phases in the Sn phase distributed in the surface layer is 10 μm or less, the Al phase distributed between the Sn phases in the sliding surface is extruded onto the sliding surface. It becomes easier to cover with the Sn phase. Thereby, the non-seizure property of the surface layer can be further improved, and the non-seizure property of the Al alloy bearing can be further improved.
Furthermore, when the average value of the interphase distance between adjacent Sn phases in the surface layer is 7 μm or less, the Al phase distributed on the sliding surface is more easily covered with the Sn phase, and the non-seizure property described above is obtained. It becomes easier to obtain the effect.
Therefore, in this surface layer, Sn is included in an amount of 30 to 70% by mass, the average value of the interphase distance between adjacent Sn phases is 10 μm or less, and the average value of the aspect ratio of the Sn phase is 4 or more. The above-mentioned non-seizure effect can be obtained.

  The average value of the thickness dimension of the surface layer is preferably 50 μm or more. When the average thickness of the surface layer is 50 μm or more, the number of Sn phases extending and distributed in the thickness direction of the surface layer can be easily increased. Therefore, the Sn phase of the surface layer is more easily pushed onto the sliding surface by the pressure from the Al phase, and the Al phase distributed on the sliding surface is more easily covered with this Sn phase. Thereby, the non-seizure property of the surface layer can be further improved, and the non-seizure property of the Al alloy bearing can be further improved.

  The anti-surface layer contains Al and 30 to 50% by mass of Sn, has an Al phase made of Al, and an Sn phase made of Sn, and an average interphase distance between adjacent Sn phases is 10 μm or more. Preferably there is. The average value of the interphase distance between adjacent Sn phases in the anti-surface layer is also based on the distance between the centroids of adjacent Sn phases in the same manner as the average value of the interphase distance between adjacent Sn phases in the surface layer. Is required.

The relationship of the interphase distance between adjacent Sn phases in the anti-surface layer will be described with reference to FIG. FIG. 4 shows the distribution and shape of the Sn phases 7 and 8 having the same area ratio of the Sn phase in the measurement field of view but different average values of the interphase distances between the adjacent Sn phases in the anti-surface layer. 10 shapes are schematically shown. FIG. 4A shows an example of a plurality of Sn phases 7 and a matrix 9 having a large average interphase distance, and it is assumed that the Sn phases 7 are all arranged at equal intervals in the same shape. is there. In this case, indicating the area of each Sn phase 7 of the measurement visual field as S _3. FIG. 4B shows an example of a plurality of Sn phases 8 and a matrix 10 having an average interphase distance smaller than that in the case of the Sn phase 7, and the Sn phases 8 are all the same shape and arranged at equal intervals. It is assumed that In this case, indicating the area of each Sn phase 8 of the measurement field as S _4.
As shown in FIG. 4, the larger the average value of the interphase distances between adjacent Sn phases in the anti-surface layer, the smaller the number of Sn phases distributed in the measurement field of view, and the area of the Sn phase per piece. As a result, the total length of the boundary between the Al phase and the Sn phase in the measurement field of view decreases.

  The shorter the total length, that is, the smaller the total area of the interface where the Al phase and Sn phase are in contact with each other, the smaller the total area of the starting points that can cause poor adhesion between the Al phase and the Sn phase. Then, as the total area of the starting points becomes smaller, the possibility that the above-described starting points exist between the anti-surface layer and the base material is reduced, and the anti-surface layer is firmly bonded to the base material. Therefore, an Al-based bearing alloy layer having excellent non-seizure properties is obtained by increasing the interphase distance between adjacent Sn phases in the anti-surface layer, for example, by setting the average value of interphase distances between adjacent Sn phases to 10 μm or more. It can be firmly bonded on top.

Therefore, in this anti-surface layer, 30-50 mass% of Sn is included, and the average value of the interphase distance between adjacent Sn phases is 10 μm or more, so that the Al phase having higher strength than the Sn phase is anti-surface. A good cushioning property can be imparted while increasing the strength of the entire anti-surface layer by appropriately distributing in the layer, and the adhesion between the base material and the Al-based bearing alloy layer can be enhanced. Therefore, such an Al alloy bearing is extremely excellent in non-seizure properties.
Moreover, it is preferable in terms of improving the non-seizure property and fatigue strength of the Al alloy bearing that the average value of the interphase distance between adjacent Sn phases in the anti-surface layer is larger than that in the surface layer.

The average value of the phase distance Sn phase adjacent the surface layer and A _1, when the average value of the phase distance Sn phase adjacent the reaction surface layer and A _2, the value A _{2 /} A ₁ ratio is 3 The above is preferable. Anti-seizure property of the larger the value of A ₁ is small surface layer is improved, the Al-base bearing alloy layer and improve the adhesion between the larger the value of A ₂ is greater substrate and the Al-base bearing alloy layer on a substrate It can be firmly bonded. When the ratio value A ₂ / A ₁ is 3 or more, the non-seizure property of the entire Al alloy bearing can be further improved.

You may anneal-treat to the Al alloy bearing of one Embodiment of this invention mentioned above. Even if the Al alloy bearing of one embodiment of the present invention is annealed, the non-seizure effect equal to or higher than that of the Al alloy bearing before the annealing treatment is obtained.
Further, as described above, by annealing the Al alloy bearing, as schematically shown in FIG. 5, many of the Sn phases 11 distributed in the surface layer are connected to the other Sn phases 11, and the Al phase 12 An annular Sn phase 13 is formed to surround. Fig.5 (a) is a figure which shows the surface layer before annealing, FIG.5 (b) is a figure which shows the surface layer after annealing.

When the average value of the circumferential length l of the annular Sn phase is L and the average value of the width d of the annular Sn phase is D, the ratio value L / D is preferably 10 or more.
As schematically shown in FIG. 5, the circumferential length l of the annular Sn phase 13 is such that the Al phase 12 distributed in the measurement visual field is regarded as a circle of the same area, and the Sn phase surrounding the Al phase 12 is In the case of an annular shape, the circumference of a circle formed as a diameter is obtained by adding the diameter h of the Al phase 12 regarded as a circle and the width d of the annular Sn phase (annular Sn phase 13). is there.

Here, the average diameter H of the Al phase after annealing and the average value D of the length in the width direction of the annular Sn phase are obtained as follows.
As shown in FIG. 5, the average diameter H of the Al phase surrounded by the annular Sn phase is surrounded by the annular Sn phase 13 when, for example, a line (dotted line) Lp extending in the vertical direction is drawn on the composition image of the measurement visual field. It is set as the average value of the length per one part where the line Lp has overlapped with the Al phase 12 which is.

  The average value D of the lengths in the width direction of the annular Sn phase is obtained as follows. First, in the same manner as described above, a line Lp is drawn on the composition image of the measurement visual field, and the average value of the length per part where the line Lp overlaps the annular Sn phase is obtained. Since the length per location can be assumed to be the shortest distance between the outer peripheral portions of adjacent Al phases, that is, the length in the width direction of two adjacent annular Sn phases, the average value of the length per location is 2. By dividing, an average value D of the lengths in the width direction of one annular Sn phase is obtained.

  Here, when the ratio value L / D is 10 or more, as in the case where the average value of the aspect ratio of the Sn phase is 4 or more, the annular Sn phase has an elongated shape, The area of the annular Sn phase is small. Therefore, the cyclic Sn phase is easily pushed out from the inside of the surface layer onto the sliding surface by the pressure from the Al phase. As a result, the Al phase distributed on the sliding surface is easily covered by the annular Sn phase extruded on the sliding surface, and the counterpart member is less likely to directly hit the Al phase that is harder than the annular Sn phase. Become. Thereby, according to the structure of one Embodiment of this invention, the non-seizure property of a surface layer can be improved further, and the non-seizure property of an Al alloy bearing can be improved further.

  The average diameter of the Al phase surrounded by the cyclic Sn phase distributed in the surface layer is preferably 10 μm or less. When the average diameter of the Al phase surrounded by the cyclic Sn phase is 10 μm or less, the Al phase surrounded by the cyclic Sn phase is likely to be covered by the cyclic Sn phase extruded on the sliding surface. Thereby, the non-seizure property of the surface layer can be further improved, and the non-seizure property of the Al alloy bearing can be further improved.

Examples of the method for forming the surface layer on the sliding surface side of the Al bearing alloy layer include the following. In addition, the layer which has Al as a main component before forming a surface layer in an Al base bearing alloy layer is called an Al base layer.
The first method of forming the surface layer is to form a surface layer on the sliding surface side of the Al base layer by performing laser treatment and cooling treatment on the surface of the Al base layer containing a predetermined amount of Al and Sn. . In that case, the substrate side of the Al base layer is the anti-surface layer.
In the laser treatment in this surface layer forming method, a treatment is performed in which the surface of the Al base layer is irradiated with laser and the surface of the Al base layer is heated until both Al and Sn are melted.

In the cooling process using the surface layer forming method, a two-stage process including a first cooling process and a second cooling process is performed. In the first cooling treatment, the surface of the Al base layer melted by the laser treatment is heated to a temperature at which Sn is liquid and Al is both liquid and solid, specifically 350 to 500 ° C. Cool and hold at this temperature for a predetermined time to crystallize the required amount of Al phase. The amount (volume ratio) of the solid phase Al phase crystallized here is adjusted, for example, by changing the holding temperature and time. In the subsequent second cooling process, a process of cooling the surface of the Al base layer to crystallize the Sn phase after the first cooling process is performed. At this time, the Sn phase is crystallized in the gap between the Al phases crystallized by the first cooling, and the Al phase remaining in the liquid after the first cooling treatment is also crystallized during the second cooling treatment. To do.
Thus, by performing the first cooling process and the second cooling process as the cooling process after the laser process, the gap between the Al phases can be controlled, so that the aspect ratio of the Sn phase can be increased.

  Second, the surface layer is formed by applying the same laser treatment and cooling treatment to the Sn powder supplied on the Al base layer and the surface of the Al base layer as described above, and forming the surface layer on the sliding surface side of the Al base layer. It is a method of forming. That is, in the laser processing, Sn powder is supplied to the surface of the Al base layer, laser is applied to the surfaces of the Sn powder and the Al base layer, and heating is performed until the surfaces of the Sn powder and the Al base layer are melted. At this time, since the surface of the Al base layer is also melted by the laser irradiation, a part of the molten Al base layer forms an Al phase of the surface layer.

Also, in the cooling process in this surface layer forming method, a process for crystallizing a necessary amount of Al phase on the surface layer is performed by the first cooling process, and the Sn phase is converted by the second cooling process. Processing to crystallize in the gap between the Al phases is performed. In place of Sn powder, Al—Sn alloy powder may be used.
The mass ratio of Al and Sn in the surface layer is adjusted, for example, by changing the amount of Sn powder and the mass ratio of Al and Sn contained in the Al base layer.

The laser processing conditions and cooling processing conditions vary depending on the mass of Al and Sn contained in the surface layer of the Al-based bearing alloy layer.
Further, the method of forming the surface layer is not limited to the method described above.

Sectional drawing which shows typically the Al alloy bearing of one Embodiment of this invention Conceptual diagram for explaining aspect ratio Cross-sectional view of the surface layer schematically showing the shape of the Sn phase with different aspect ratios The figure which shows typically the relationship between the distance between Sn phases and the magnitude | size of Sn phase in an anti-surface layer The figure which shows the state of the surface layer before and after annealing typically The figure which shows the state of the surface layer after performing annealing treatment

A cross section of an embodiment of an Al alloy bearing is shown in FIG. An Al alloy bearing 21 shown in FIG. 1 is a bearing used in, for example, an internal combustion engine of an industrial machine, and includes a base material 22 and an Al-based bearing alloy layer 23 provided on the base material 22. The base material 22 includes a back metal layer 24 and an intermediate layer 25 provided on the back metal layer 24. The Al-based bearing alloy layer 23 has a two-layer structure having an anti-surface layer 26 in contact with the intermediate layer 25 and a surface layer 27 provided on the anti-surface layer 26.
The state of the surface layer of the Al alloy bearing after annealing the Al alloy bearing 21 is shown in FIG.

Next, the test which confirmed the effect of the Al alloy bearing 21 of this embodiment is demonstrated.
Example products 1 to 10 having the same configuration as that of the Al alloy bearing 21 of the present embodiment were obtained as follows. First, a plate material of an Al-based bearing alloy adjusted to the composition shown in Table 1 as necessary was produced by casting. After that, a thin plate material constituting the intermediate layer made of Al is pressed against the cast Al-based bearing alloy to produce a multilayer aluminum alloy plate, and this multilayer aluminum alloy plate is used as a steel plate constituting the back metal layer. The plate for bearing formation, so-called bimetal was manufactured by pressure welding and annealing.

  Next, in the example products 1, 3 to 6, laser processing was performed by irradiating the surface of the bimetallic Al base layer with laser to melt the surface of the Al base bearing alloy. Next, the 1st cooling process which cools the surface of the molten Al base bearing alloy to 350-500 degreeC, and hold | maintains for a predetermined time was performed. Then, after the first cooling process, a second cooling process for further cooling the surface of the Al-based bearing alloy to crystallize the Sn phase was performed. As a result, Example products 1, 3 to 6 having the surface layer 27 on the sliding surface side of the Al-based bearing alloy layer 23 were obtained.

In Example products 2 and 7, Sn powder was sprayed on the surface of the bimetallic Al base layer, and then laser treatment was performed to melt the surface of the Al base bearing alloy and the Sn powder. Next, the first cooling treatment and the second cooling treatment similar to those described above are performed on the surface of the molten Sn powder and the Al-based bearing alloy, and after the Al phase is crystallized, the Sn phase is crystallized. It was. Thereby, Example products 2 and 7 having the surface layer 27 on the sliding surface of the Al-based bearing alloy layer 23 were obtained.
Example products 8 to 10 were obtained by annealing Example product 6 at 250 to 350 ° C. for 4 to 6 hours.

The surface of the bimetal of Comparative Example Product 1 is made of an Al-based bearing alloy, and is not subjected to laser treatment and cooling treatment after laser treatment.
The comparative example products 2 and 3 are different from the manufacturing method of the example product in the process of cooling treatment, and after performing the same laser treatment as the example products 1 to 7, the example products 1 to 7 were performed. Without performing the first cooling treatment and the second cooling treatment, the surface layer was continuously cooled from the molten state to the solidified state to obtain an Al phase and an Sn phase.

  Table 1 shows the characteristics of Examples 1 to 10 and Comparative Examples 1 to 3 obtained by the above-described manufacturing method. In Table 1, “Surface distance”, “Sn phase aspect ratio”, “Al phase average diameter”, “R / D” and “Thickness” are bimetallic Al base bearings. It adjusts by changing suitably the composition which forms an alloy, the application | coating amount of Sn powder, the intensity | strength of laser irradiation, irradiation time, etc. Furthermore, in Example goods 1-10 and comparative example goods 2 and 3, it is 1st. It was also adjusted by appropriately changing the temperature and time of Sn phase crystallization in the cooling treatment.

  For the samples of Examples 1 to 10 and Comparative Examples 1 to 3 described above, a seizure test was performed under the conditions shown in Table 2. The test results are shown in Table 1. The oil used for the seizure test was applied on the sliding surface before the test.

“Al” and “Sn” in Table 1 indicate mass% concentrations of compositions contained in the surface layer and the anti-surface layer. These mass% concentrations are values obtained using a fluorescent X-ray apparatus.
“Sn-phase interphase distance” of “surface layer” in Table 1 indicates an average value of inter-phase distances between adjacent Sn phases of the surface layer, and “Sn-phase aspect ratio” of “surface layer” is Sn of the surface layer. The average aspect ratio of the phases is shown. In addition, these values and “average diameter of Al phase” and “ratio L / D” of “after annealing” in Table 1 indicate that the Al-based bearing alloy layer is polished from the sliding surface of the surface layer toward the substrate side. This is a value obtained by measuring at a position 20 μm deep from the most depressed portion of the sliding surface of the surface layer and measuring in a measurement visual field of 150 μm × 150 μm parallel to the sliding surface.

In this case, the average value of the interphase distance between adjacent Sn phases of the surface layer is obtained by analyzing the composition image of the measurement visual field obtained with an electron microscope ("Image-Pro Plus (Version 4.5) manufactured by Planetron Co., Ltd.)" )). Further, the average value of the phase distance Sn phase adjacent the surface layer A _1.
In addition, when calculating | requiring the average value of the interphase distance of adjacent Sn phases of a surface layer, Sn phase of the area more than the minimum (0.07 micrometer < ² >) of detection of analysis software was made into object.

The average value of the aspect ratio of the Sn phase of the surface layer was determined as follows using the analysis software described above. First, the total area of the Sn phase in the measurement visual field was determined from the areas of all Sn phases of 0.07 μm ² or more distributed in the measurement visual field, and the aspect ratio was determined for each of these Sn phases. Next, the area of the Sn phase is accumulated in order from the Sn phase having the largest aspect ratio, and the Sn phase having a large aspect ratio until the accumulated area reaches 50% of the total area of the Sn phase is averaged for the aspect ratio. It was set as the object of Sn phase which asks for. The average value of the aspect ratio of the Sn phase of the surface layer is a value obtained by averaging the aspect ratio of the Sn phase as the target.

  The “average diameter of Al phase” in “after annealing” in Table 1 is obtained by drawing lines Lp extending in the vertical direction at intervals of 10 μm in the composition image of the measurement visual field, for example, as shown in FIG. The lines Lq extending in the lateral direction are drawn at intervals of 10 μm, and the length per one part where the respective Al lines 12 are overlapped with the respective lines and the Al phase 12 surrounded by the annular Sn phase 13 (Al phase pseudo-diameter length). ) Is an average value. In the measurement of the average diameter of the Al phase, the Al phase not surrounded by the annular Sn phase 13 in the measurement visual field was excluded from the measurement. In addition, when the Sn phase 11 is scattered in the Al phase 12 surrounded by the annular Sn phase 13 and the Sn phase 11 overlaps the above-described lines, the Sn phase 11 is assumed not to exist, and the Al phase The average diameter was determined.

D of “ratio L / D” of “after annealing” in Table 1 is an average value D of the lengths in the width direction of the annular Sn phase. The value of D is a value obtained by dividing the average value of the length per part where each line used for the average diameter of the Al phase and the annular Sn phase 13 overlap by 2. In addition, in the measurement of D, the Sn phase 11 that was not in a ring shape was not measured.
L in “Ratio L / D” of “After annealing” in Table 1 is an average value L of the circumferential length of the annular Sn phase. The value of L is a value obtained by averaging the circumferential length of a virtual circle whose diameter is the sum of the Al phase pseudo-diameter length and the width direction length of the annular Sn phase.
“Ratio L / D” in Table 1 is the ratio value L / D, which is obtained by dividing the above-mentioned L by D.
The value of “thickness” of “surface layer” in Table 1 is a value obtained by measuring film thicknesses at a plurality of locations on the surface layer from a cross-sectional photograph of the surface layer and averaging them.

“Sn-phase interphase distance” of “anti-surface layer” in Table 1 indicates an average value of inter-phase distances between adjacent Sn phases of the anti-surface layer. This value is obtained by grinding the Al-base bearing alloy layer by polishing from the sliding surface of the surface layer toward the base material, and at a position 20 μm in height from the position closest to the Al-base bearing alloy layer of the base material. The value obtained by measurement in a measurement visual field of 150 μm × 150 μm on a plane parallel to the sliding surface.
In this case, the average value of the interphase distance between adjacent Sn phases in the anti-surface layer is also the distance between the centers of gravity of adjacent Sn phases in the anti-surface layer, and the inter-phase distance between adjacent Sn phases in the above-described surface layer. This is a value obtained by using the above-described analysis software, in the same manner as the method for obtaining the average value. The average value of the phase distance Sn phase adjacent the anti-surface layer and A _2.
“Ratio A ₂ / A ₁ ” in Table 1 is a ratio value A ₂ / A _1, which is a value obtained by dividing the above-mentioned A ₂ by A ₁ .

Next, the results of the seizure test are analyzed.
From comparison between the example products 1 to 7 and the comparative example products 1 to 3, in the example products 1 to 7, the average value of the interphase distance between adjacent Sn phases in the surface layer is 10 μm or less, and the Sn phase Since the average value of the aspect ratio is 4 or more, it can be understood that the non-seizure property is superior to Comparative Examples 1 to 3.

From comparison between the example product 1 and the example products 2 to 7, the example product 2 to 7 has an average value of the thickness dimension of the surface layer of 50 μm or more. It can be understood that it is even better.
From comparison between the example products 1 and 2 and the example products 3 to 7, the example products 3 to 7 have an average interphase distance between adjacent Sn phases in the anti-surface layer of 10 μm or more. It can be understood that the non-seizure property is much better than the products 1 and 2.

From comparison between the example products 1 to 3 and the example products 4 to 7, the example products 4 to 7 have a ratio value A ₂ / A ₁ of 3 or more. It can be understood that the seizure property is even better.
From comparison between the example products 1 to 4 and the example products 5 to 7, in the example products 5 to 7, the average value of the interphase distance between adjacent Sn phases in the surface layer is 7 μm or less, and the Sn phase Since the average value of the aspect ratio is 6 or more, it can be understood that the non-seizure property is more excellent than the examples 1 to 4.

From the comparison between the example product 6 and the example products 8 to 10, it can be understood that the example product 8 to 10 has a non-seizure property equal to or higher than that of the example product 6 before annealing.
From comparison between the example product 8 and the example products 9 and 10, the example product 9 and 10 have a non-seizure property than the example product 8 because the ratio value L / D is 10 or more in the surface layer. It can be understood that it is even better.
From comparison between the example products 8 and 9 and the example product 10, since the average diameter of the Al phase surrounded by the annular Sn phase in the surface layer of the example product 10 is 10 μm or less, from the example products 8 and 9 It can be understood that the non-seizure property is even better.

The present embodiment can be implemented with appropriate modifications within a range not departing from the gist.
Description of inevitable impurities is omitted, and each composition may contain inevitable impurities.
In the Al-based bearing alloy layer and the intermediate layer, additives other than Al and Sn, for example, Cu, Si, Mn, Zr, Fe, etc., additives such as hard particles and solid lubricants, etc., as long as the effects of the present invention are not impaired May be added.

  In the drawings, 1, 3, 7, and 11 are Sn phases, 2, 5, 9, and 12 are matrices (Al phases), 13 is an annular Sn phase, 21 is an Al alloy bearing, 22 is a base material, and 23 is an Al base bearing. An alloy layer, 24 is a back metal layer, 25 is an intermediate layer, 26 is an anti-surface layer, 27 is a surface layer, and 28 is a sliding surface.

Claims (8)

An Al-based bearing alloy layer is provided on the substrate,
The Al-based bearing alloy layer has a surface layer containing Al and 30 to 70% by mass of Sn on the sliding surface side,
The surface layer has an Al phase composed of Al and a Sn phase composed of Sn, an average value of an interphase distance between adjacent Sn phases is 10 μm or less, and an average aspect ratio of the Sn phase An Al alloy bearing having a value of 4 or more and an orientation in which the long axis of the Sn phase intersects the sliding surface.   2. The Al alloy bearing according to claim 1, wherein an average value of thickness dimensions of the surface layer is 50 [mu] m or more. The base material has a back metal layer, and an intermediate layer provided between the back metal layer and the Al-based bearing alloy layer,
The Al-based bearing alloy layer has an anti-surface layer in contact with the intermediate layer,
The anti-surface layer includes Al and 30 to 50% by mass of Sn, has an Al phase composed of Al and a Sn phase composed of Sn, and an average value of an interphase distance between adjacent Sn phases is The Al alloy bearing according to claim 1, wherein the Al alloy bearing is 10 μm or more. A ratio value A ₂ / A ₁ of the average value A ₁ of the interphase distance between the Sn phases adjacent in the surface layer and the average value A ₂ of the interphase distance between the Sn phases adjacent in the anti-surface layer is The Al alloy bearing according to claim 3, wherein the number is 3 or more.   5. The average value of the interphase distance between the adjacent Sn phases in the surface layer is 7 μm or less, and the average value of the aspect ratio of the Sn phase is 6 or more. An Al alloy bearing according to claim 1. An Al-based bearing alloy layer is provided on the substrate,
The Al-based bearing alloy layer has a surface layer containing Al and 30 to 70% by mass of Sn on the sliding surface side,
The surface layer has an Al phase made of Al and an Sn phase made of Sn,
The Sn phase has an average interphase distance between adjacent Sn phases of 10 μm or less, an average aspect ratio of the Sn phase of 4 or more, and the long axis of the Sn phase is on the sliding surface. The Sn phases that are in a crossing direction are connected in a ring shape, and the annular Sn phase surrounds the Al phase,
An Al alloy bearing in which a ratio L / D of an average value L of the circumferential direction length of the annular Sn phase and an average value D of the width direction length of the annular Sn phase is 10 or more. The Al alloy bearing according to claim 6 , wherein the surface layer has an average diameter of the Al phase surrounded by the annular Sn phase of 10 μm or less. A method for producing an Al alloy bearing according to claim 6 or 7, comprising:
The manufacturing method of the Al alloy bearing which anneals and forms the Al alloy bearing as described in any one of Claim 1 to 5.

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