JP3421724B2 - Copper-based sliding material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copper-based sliding material having excellent wear resistance and non-seizure resistance, and particularly suitable as a material for bushes, thrust washers, etc. in automobiles, industrial machines, agricultural machines, etc. System sliding material.

[0002]

Bushings, thrust washers, etc. in automobiles, industrial machines, agricultural machines, etc.
Conventionally, sintered alloys such as bronze and lead bronze have been mainly used, and these alloys exhibit good sliding characteristics under the operating conditions in which lubricating oil is present. However, the above copper-based alloy is a boundary lubrication region where an oil film is not sufficiently formed when a low-viscosity lubricant is used or when sufficient lubrication is not made, and in particular, it is inferior in wear resistance and has sufficient sliding characteristics. Was not obtained.

In order to improve the wear resistance in the boundary lubrication conditions, the applicant has filed Japanese Patent Application No. Hei 2-333283 and (Hei 4-1984 4 No. 0). The composition of the sintered alloy is 1 to 15 wt% Sn, 1 to 20 wt% Ni-B, 1 wt% or less P, and the balance Cu. According to this sintered alloy, hard Ni-B is C
Disperses in u alloy and improves wear resistance. However,
With this sintered alloy, sufficient wear resistance cannot be obtained under the condition of one-sided contact under high surface pressure or in the condition where abrasive wear is likely to occur.

To improve this, the present applicant further applied for Japanese Patent Application No. 10-112799. This is 2
A Cu-Sn-Pb alloy containing 30 to 30% by weight of Pb dispersed therein contains a copper-based sliding material containing 0.1 to 6 volume% of hard particles having an average particle diameter of 5 to 25 μm in the Pb phase. And According to the copper-based sliding material having this composition, Pb forms a Pb phase in which the Pb is dispersed in the matrix of the copper alloy, and the hard particles are incorporated in this Pb phase, so that wear resistance and non-seizure property are obtained. To be demonstrated. However, Pb is used in this improved copper-based sliding material. Since Pb has an adverse effect on the environment, it is preferable to reduce the addition amount and avoid its use if possible.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the amount of Pb added and, if possible, to improve wear resistance and non-seizure resistance without using copper. The purpose is to provide a sliding material.

[0006]

The copper-based sliding material according to claim 1 comprises 0.5 to 15% by weight of Sn and 1 to 20% by weight of B.
i , 0 . 1-10% by volume of hard particles, Ri such a balance Cu <br/>, wherein Bi is dispersed in the Cu alloy matrix,
The hard particles have an average particle size of 1 to 45 μm,
And it is characterized in that are mixed into phase.

Bi is dispersed in a Cu alloy matrix to form a Bi phase. Then, hard particles are mixed in this Bi phase. Dispersion of the soft Bi phase in the Cu alloy matrix improves the conformability, foreign matter embeddability and non-seizure property. The hard particles contribute to the improvement of wear resistance. By the hard particles are mixed in the Bi phase,
It excels in wear resistance and improves non-seizure property. Also,
The hard particles are mixed in the soft Bi phase , so that FIG.
As shown in (1), the soft Bi phase acts as a cushion on the sliding surface, and the attack of the hard particles exposed on the surface of the matrix against the mating material is relaxed.

In the Bi phase in the absence of hard particles,
As shown in FIG. 3, Bi is easily carried away on the sliding surface during sliding and is inferior in wear resistance, but in the copper-based sliding member according to claim 1, the presence of hard particles prevents Bi from flowing out. To be done.
Further, even if the hard particles fall off, they are again captured by the other Bi phases due to the embedding property of the Bi phase, so that the abrasive wear is alleviated.

Bi forms a soft Bi phase dispersed in a Cu alloy matrix in an amount of 1 to 20% by weight, and improves the wear resistance, anti-seizure property and cushioning property. When Bi is less than 1% by weight, the effect of non-seizure property cannot be obtained, and hard particles are not sufficiently taken in, so that the partner material may be attacked. If Bi exceeds 20% by weight, the strength decreases.

Hard particles of 0.1 to 10% by volume improve the wear resistance and anti-seizure property. If the hard particles are less than 0.1% by volume, no improvement in wear resistance is observed and 10% by volume
If it exceeds, the attack property to the partner material increases. Also,
The present invention is characterized in that the hard particles have an average particle size of 1 to 45 μm. When the average particle diameter of the hard particles is less than 1 μm, it becomes difficult to uniformly disperse it in the Bi phase, and no remarkable improvement in wear resistance is observed. When the average particle size exceeds 45 μm, particularly when Bi is small, the effect of cushioning the Bi phase and the effect of burying the hard particles that have fallen off are not seen, and the attack property to the mating material increases.

Sn strengthens the Cu matrix. Sn
If less than 0.5% by weight, the effect of strengthening the strength of the Cu matrix cannot be obtained, and if more than 15% by weight, Cu-
A large amount of Sn compound is formed and becomes brittle.

As the hard particles, a boride, a silicide, an oxide of a metal, such as the copper-based sliding material according to claim 2, can be used.
It can be a nitride, a carbide, or an intermetallic compound. The copper-based sliding material according to claim 3 is characterized by containing 40% by weight or less in total of one or more of Fe, Al, Zn, Mn, Co, Ni, Si and P. . 40% by weight or less of Fe, Al, Zn, Mn, Co, Ni, S
i and P form a solid solution in the Cu matrix and contribute to the improvement of the strength of the Cu matrix.

The copper-based sliding material according to claim 4 has a total amount of 2
It is characterized by containing 0% by volume or less of MoS ₂ , WS ₂ , BN, and graphite in one kind or two or more kinds.
MoS ₂ , WS ₂ , BN, and graphite function as solid lubricants. These solid lubricants improve wear resistance and anti-seizure property due to their lubricity. When the above solid lubricant exceeds 20% by volume, the strength decreases.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention is applied to a bearing and described with reference to the drawings. The bearing 1 shown in FIG. 4 is called a bush, and for example, a sliding material 4 according to the present invention is provided on a backing metal 2 formed of a thin steel plate with an adhesive layer 3 interposed therebetween.
It will be attached. The adhesive layer 3 is for firmly attaching the sliding material 4 to the backing metal 2, and is made of, for example, nickel, copper, or an alloy of nickel and copper.

The sliding material 4 is made of Cu and is made of Sn0.
5 to 15% by weight, Bi 1 to 20% by weight, hard particles 0.1
-10% by volume, the balance consisting essentially of copper and unavoidable impurities. In this case, the hard particles have an average particle size of 1 to 45 μm.
It is preferably composed of m powder. As hard particles,
Metal borides, silicides, oxides, nitrides, carbides,
Intermetallic compounds are possible.

Here, as the boride, NiB, Ni
3B, CrB , ZrB2, CoB, TiB2, VB2,
There are TaB2, WB, MoB, Fe-B series, etc., and as the silicide, TiSi2, WSi2, MoSi2, T
There are aSi2, CrSi2, Fe-Si-based, Mn-Si-based, and the like, and oxides include SiO2, Al2O3, and T.
iO2, ZrO2, WO, MoO3, Mn-O system, Fe
There are --O type, V--O type, etc., and the nitride is Si2.
N4, TiN, ZrN, TaN, VN, AlN, CB
N, Cr2N, etc., and carbides such as WC and Si
There are C, B4C, TiC, TaC, VC, ZrC, etc., and as the intermetallic compound, Ni-Sn system, Fe-W.
System, Fe-Mo system, Fe-Mn system, Fe-Cr system, Fe
-Al system, Cr-Al system, V-Al system, Ti-Al system,
There are W-Al type and the like. Other hard particle materials include Ni-based self-fluxing alloys (Ni-B-Si based) and Co-based self-fluxing alloys (Co-Mo-Si-B based).

The total amount of the sliding material 4 is 40% by weight.
Fe, Al, Zn, Mn, Co, Ni, Si, P below
1 type or 2 types or more can be included. in this case,
Fe 4 wt% or less, Al 10 wt% or less, Zn 3
5 wt% or less, Mn is 10 wt% or less, Co is 5 wt%
Below, Ni is 40 wt% or less, Si is 5 wt% or less, P
Is preferably 0.5% by weight or less. Furthermore, as a solid lubricant, a total amount of 20% by volume or less of MoS ₂ , WS
₂ , BN, and graphite may be included in one kind or two or more kinds.

Here, an example of the manufacturing procedure of the bearing 1 will be described. First, 1 to 20 % by weight of Bi powder, 0.1 to 1
0% by volume hard particles, 0.5-15% by weight Sn powder,
The balance Cu powder is mixed to obtain a mixed powder for forming the sliding material 4. In this case, it is preferable that the Bi powder, Sn powder, and Cu powder have a particle diameter of 250 μm or less, and the hard particles have an average particle diameter of 1 to 45 μm. In addition, Fe, Al, Zn, M of 250 μm or less
The total amount of one or more powders selected from n, Co, Ni, Si and P is 40% by weight or less, or M
Solid lubricating powders such as oS2, WS2, BN and graphite may be mixed. Further, the powder of each composition described above is not limited to a single powder, and may be an alloy powder. Thereafter, the composite sintered material produced as described above is cut into a predetermined size, bent into a cylindrical shape, and the surface of the sliding material 4 is machined. From the above, FIG.
The bearing 1 shown in is obtained.

Such a mixed powder (sliding material 4) is evenly dispersed on the surface of the adhesive layer 3 electrically plated with copper on the steel plate (back metal 2), and the mixture is heated at 750 to 950 ° C. in a reducing atmosphere. It was sintered at a temperature for 20 minutes and then rolled. Further, in order to densify the sliding material 4 and increase the joint strength with the steel sheet, the sintering was repeated to produce a composite sintered material. Then, Bi having a low melting point is melted during sintering, and the melted B is melted.
Hard particles are mixed in the i phase.

FIG. 1 (a) is a schematic photomicrograph showing the structure of the sliding material 4 produced in this manner, in which the Bi phase is dispersed in the Cu alloy matrix and Hard particles are mixed. Note that FIG. 1 (b)
Is a schematic photomicrograph of a comparative product.
The Sn alloy contains graphite powder and a hard material, and the hard material is mixed in the matrix of the Cu alloy. Thereafter, the composite sintered material produced as described above is cut into a predetermined size, bent into a cylindrical shape, and the surface of the sliding material 4 is machined. As described above, the bearing 1 shown in FIG. 4 is obtained.

Now, the inventor conducted an abrasion test and a seizure test for the example product and the comparative product having the compositions shown in Table 1 below. The abrasion test was conducted under the conditions shown in Table 2 and the seizure test was conducted under the conditions shown in Table 3.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

As is clear from Table 1 above, Examples 1 to 8 are superior in wear resistance (bearing wear amount) and non-seizure property (maximum surface pressure without seizure) as compared with Comparative Products 1 to 6. At the same time, the attack on the other axis (the amount of change in the other axis) is small. Table 1 above is analyzed in detail. First, comparative product 1 is B
It contains Pb instead of i, but does not contain hard particles.
Comparative product 3 contains Bi but does not contain hard particles. In Comparative Products 1 and 3 which do not contain these hard particles, both the wear resistance and the non-seizure property are poor, and especially the wear resistance is very poor.

On the other hand, the comparative product 4 contains 7% by volume of hard particles. However, since this comparative product 4 does not contain Bi, when compared with the example products 2 and 6 containing Bi,
In addition to being inferior in wear resistance and non-seizure property, since it does not contain Bi which functions as a cushion of hard particles, it has a strong attack on the mating shaft (the amount of mating shaft change is large).

Comparative product 2 contains hard particles and does not contain Bi as in comparative product 4. However, although this comparative product 2 is equivalent to the product of the example in non-seizure property,
It is considered that the reason is that the comparative product 2 contained graphite (Gr) and therefore exhibited its lubricity.

Comparative product 5 contains hard particles and Bi. This comparative product 5 has the same level of wear resistance and non-seizure property as that of the example product, but since it also contains 12% by volume of hard particles exceeding 10% by volume, the contents of Sn and Bi are the same. The amount of wear of the mating shaft is larger than that of the products of Examples 1, 7, and 8. It is considered that this is because the amount of hard particles increased, so that the attackability against the mating shaft became stronger.

Comparative product 6 also contains hard particles and Bi. However, in this comparative product 6, since the average particle diameter of the hard particles is as large as 55 μm, the attacking property against the mating shaft becomes strong, and the bearing wear amount, compared with the product 1 of the embodiment in which the content of the hard substance is the same, It can be seen that not only the anti-seizure property but also the wear amount of the mating shaft is particularly large.

As described above, according to the present invention, it is understood that a copper-based sliding material which can improve wear resistance and non-seizure property can be provided without using Pb.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following expansions or modifications are possible. It can also be used as a main bearing that is formed in a semicircular shape and receives the crankshafts that are used in pairs, or as a bearing that is provided at the large end of the connecting rod. It is not limited to bearing materials such as sliding bearings used in automobiles, industrial machines, agricultural machines, etc., and can be widely applied to sliding materials in general. The sliding material 4 is not limited to one manufactured by sintering, and may be one manufactured by extrusion, forging, or casting. Although the embodiment is described as not containing Pb at all, some Pb may be contained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an electron micrograph showing the structure of a sliding bearing according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state of hard particles on a sliding surface.

FIG. 3 is a sectional view showing a state of Bi on a sliding surface.

FIG. 4 is a sectional view of the bearing.

[Explanation of symbols]

In the figure, 1 is a bearing, 2 is a back metal, 3 is an adhesive layer, and 4 is a sliding material.

Front Page Continuation (72) Inventor Takashi Inaba, 2nd Sanagecho, Kita-ku, Nagoya City, Daido Metal Industry Co., Ltd. (72) Inventor, Koichi Yamamoto 2nd, Sanagecho, Kita-ku, Nagoya City, Daido Metal Industry Co., Ltd. (72) Inventor Takayuki Shibayama, 2nd Sanage-cho, Kita-ku, Nagoya, Daido Metal Industry Co., Ltd. (56) Reference JP-A-55-164050 (JP, A) JP-A-11-124646 (JP, A) JP-A-9- 324228 (JP, A) JP 10-330868 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C22C 9/02 C22C 9/00 F16C 33/12

Claims (4)

(57) [Claims] 1. 0.5 to 15% by weight of Sn , 1 to 20% by weight of Bi , 0 . 1-10% by volume of hard particles , balance Cu
The Bi particles are dispersed in the Cu alloy matrix , and the hard particles have an average particle size of 1 to 45 μm.
Copper-based sliding material, characterized in that are mixed into phase. 2. The copper-based sliding material according to claim 1, wherein the hard particles are metal borides, silicides, oxides, nitrides, carbides and intermetallic compounds. 3. Fe, Al, Z in a total amount of 40% by weight or less
The copper-based sliding material according to claim 1 or 2, which contains one or more of n, Mn, Co, Ni, Si, and P. 4. A total amount of 20% by volume or less of MoS ₂ and WS.
The copper-based sliding material according to any one of claims 1 to 3, which contains one or two or more of ₂ , BN, and graphite.