JP2000104132A - Copper sintered sliding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sliding material having wear resistance and seizuring resistance without using Pb as a lubricating component by allowing it to have a compsn. contg. a specified ratio of Mo and/or W and a specified ratio of Bi, and the balance substantially Cu. SOLUTION: The content of Mo and/or W is 1 to 20 wt.%, and the content of Bi is 0.5 to 20 wt.%. The powder 1 of Mo and/or W alone or in combination is mixed and sintered with copper or copper alloy powder and is uniformly distributed into a copper sintered base 3. In the case an S added substance is rubbed in a lubricating oil, Mo, W and S exposed onto the surface of the sintered material are bonded to obtain a lubricating film having durability. As the lubricating component till a sulfurized film is formed on Mo and W in the initial stage of the driving, Bi 2 as a low m.p. metal is added. As to the copper sintered base 3, the rear is provided with a copper back plate. By incorporating one or >= two kinds among P, Sn, Ni and Ag in addition to Mo, W and Bi, the strengthening of the copper sintered base and its corrosion resistance can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a copper-based sintered sliding material, and more particularly to a Pb-free copper-based sintered sliding material suitable for a slide bearing for an internal combustion engine.

[0002]

2. Description of the Related Art Conventional copper-based sintered sliding materials include a phosphor bronze casting JIS 5113, a copper-lead alloy casting H5403 for a bearing, and a lead-bronze casting H5115-1958 of 0 to 42% by weight of Pb, 0 to 11% by weight of Sn or
Generally, a copper alloy powder containing Cu of 0 to 2% by weight and the balance being Cu is sintered on low carbon steel to form a bearing layer of a copper sintered alloy. Most of the copper-based sintered sliding materials for internal combustion engines contain 10 to 30% by weight of Pb, and the large-end bearings and main bearings of the connecting rods have Pb-based overlay plating on the surface.

In recent internal combustion engines, bearings are used in a high-temperature atmosphere and under high surface pressure, the lubricating oil tends to have a low viscosity, and the frequency of contact between the shaft and the bearing surface is high. Easily disappears from the bearing surface. When the bearing surface comes into direct contact with the shaft, Pb near the surface of the bearing layer is easily eluted, voids are formed in the bearing layer and the strength is reduced, and the load applied to the bearing during operation tends to cause buckling and seizure or fatigue. Problem. If Pb, which is a lubricating component, is simply removed from the copper sintered alloy to solve this problem, there is a problem that seizure is likely to occur.

Furthermore, in recent years, the use of Pb has been regulated from the environmental point of view, and there is a problem that Pb-free (Pb-free) is required.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has the same or higher wear resistance and seizure resistance as before without using Pb which is a lubricating component. An object of the present invention is to provide a copper-based sintered sliding material.

[0006]

The copper-based sintered sliding material of the present invention comprises 1 to 20% by weight of Mo and / or W, and 0.5% by weight of Mo and / or W.
-20% by weight of Bi, and the balance substantially consists of Cu.

[0007] The copper-based sintered sliding material may be 1-20.
It is characterized in that Mo and / or W by weight and Bi by 0.5 to 20% by weight further contain up to 0.4% by weight of P.

[0008] The copper-based sintered sliding material may be 1-20.
It is characterized in that Mo and / or W by weight and Bi by 0.5 to 20% by weight further contain Sn by 12% by weight or less.

[0009] The copper-based sintered sliding material may be 1-20.
It is characterized in that Mo and / or W and 0.5 to 20% by weight of Bi further contain 10% by weight or less of Ni.

[0010] The copper-based sintered sliding material is preferably 1 to 20.
It is characterized in that Mo and / or W by weight and Bi by 0.5 to 20% by weight further contain 5% by weight or less of Ag.

Further, the copper-based sintered sliding material is 1 to 20.
Wt% Mo and / or W and 0.5-20 wt% Bi, plus 0.4 wt% or less of P, 12 wt%
It is characterized by containing at least two of the following Sn, 10% by weight or less of Ni and 5% by weight or less of Ag.

Further, the copper-based sintered sliding material is characterized in that a back metal is provided on a back surface.

[0013]

Embodiments of the present invention will be described below. FIG. 1 schematically shows a cross section of a copper-based sintered sliding material according to the present invention. 1 denotes Mo or W, 2 denotes Bi, 3 denotes a copper sintered body, and 4 denotes a steel backing.

[0014] The composition obtained by simply removing Pb from the conventional copper bearing alloy is insufficient in seizure resistance, and contains a general solid lubricant such as MoS2, WS2 or graphite as a lubricating component. In order to provide lubricating properties suitable for a plain bearing, 20% by volume or more is required, and the strength of the copper bearing alloy is reduced, so that the bearing cannot be realized. For this reason, it is possible to disperse and sinter as a metal in the copper sintered body 3 and to have sufficient strength as a bearing of a natural engine,
When a sulfide film is formed on the surface, Mo or W having lubricity is contained. The reason for limiting to Mo and W is Mo
A sulfide film formed on metals other than W and W does not become a durable lubricating film because it easily disappears due to abrasion even if the sulfide film itself has lubricity, but any sulfide film on Mo or W However, it is effective as a lubricating film and has higher durability than a sulfide film on another metal. Mo and W sulfide films are naturally added to the lubricating oil of engines.
Although formed by the reaction with the system additive, when no sulfide film is formed at the beginning of the operation, seizure is easily caused by friction between the shaft and Mo or W. Therefore, as a lubricating component until a sulfide film is formed on Mo or W, B, which is a low melting point metal, is used.
i.

Further, in order to further improve the conformability at the time of the initial operation, the alloy surface of the copper-based sintered sliding material of the present invention can be coated with a normal overlay layer. That is,
An overlay plating consisting of at least one selected from In, Cu, and Pb, which requires Sn as an essential component, can also be applied. The main lubrication of the copper-based sintered sliding material of the present invention is performed by a sulfide film formed on Mo or W, and Bi is substituted for Pb.
There is no performance difference in the use of Bi, and Bi is selected and used in order to comply with Pb regulations from the environmental aspect.

The copper-based sintered sliding material of the present invention contains Mo or W powder, which is an additive component, either alone or in combination.
After mixing with the copper or copper alloy powder, the mixture is sintered and uniformly distributed in the copper sintered body 3. When friction occurs in a lubricating oil containing an S-based additive, Mo and W exposed to the surface of the sintered material are combined with S, and a durable lubricating film is obtained. If the amount of Mo or W is less than 1% by weight, the lubricity is insufficient, and if it exceeds 20% by weight, the strength of the copper sintered body 3 becomes too low as a plain bearing for an internal twist engine.

Bi is added as a lubricating component as described above, and is particularly necessary as a lubricating component until a lubricating film is formed by Mo or W and sulfide in the lubricating oil at the time of initial friction. If the amount of Bi is less than 0.5% by weight, the lubricity is insufficient and 2
If it exceeds 0% by weight, the strength of the copper sintered body 3 is too low. P is added to strengthen the copper sintered body 3, but is added in an amount of 0.1%.
If it exceeds 4% by weight, the copper sintered body 3 becomes too brittle. More preferably, it is 0.01 to 0.2% by weight. Sn is added to strengthen the copper sintered body 3 and increase the corrosion resistance.
If it exceeds 2% by weight, the copper sintered body 3 becomes too brittle. N
i is added to strengthen the copper sintered body 3 and increase the corrosion resistance, but if it exceeds 10% by weight, the copper sintered body 3 becomes too brittle. Ag is added in order to strengthen the copper sintered body 3 and increase the corrosion resistance, but if it exceeds 5% by weight, the copper sintered body 3 becomes too brittle. Next, a wear test and a seizure test performed on a sample of the copper-based sintered sliding material of the present invention will be described. Samples for the test were prepared by mixing 0 to 20% by weight of Mo or W powder of 60 μm or less into a Cu—Bi composition alloy powder (−60 mesh) manufactured by an admittance method, and then spraying 1 mm on a steel backing metal at a temperature of 750. After sintering in a reducing atmosphere at 還 元 850 ° C. for 15 to 30 minutes, cold rolling is performed with a roll, sintering is again performed under the same conditions, and then cold rolling is performed to produce a copper sintered material. Table 1 shows the sample No. for the test. 1 to 23 show compositions. Sample No. 1-2
3 is a copper alloy powder having the composition shown in Table 1 (-60 mesh)
Is manufactured by admixing, and after mixing 0 to 20% by weight of Mo or W powder of 60 μm or less, a copper sintered material is manufactured by the above sintering method. The conditions of the wear test conducted this time were: Testing machine Cylindrical flat plate friction and wear testing machine 2. 2. Sliding speed Circumferential speed 60m / min Load 200Kgf 4. Lubricating oil 10W-30 (CD class) 5. Oil temperature 120 ° C 6. 6. In lubricating oil Mating shaft S55C (hardened) 8. Shaft roughness 0.2Ra The test was performed for 120 minutes. The conditions of the seizure test conducted this time were: Testing machine Cylindrical flat plate friction and wear testing machine 2. 2. Sliding speed Circumferential speed 60m / min 3. Cumulative load at a rate of 10 kgf / 10 min. Lubricating oil 10W-30 (CD class) 6. In lubricating oil Mating shaft S55C (hardened) 8. Shaft roughness 0.2Ra Burn-in criteria Criteria were determined at a friction surface rear surface temperature of 200 ° C or higher.

FIG. 2 is a schematic view of a cylindrical flat type friction and wear tester 20 for performing a wear test and a seizure test. N shown in Table 1 between a mating shaft 21 that is rotated (arrow R) when performing a test and a shaft lower end 22A of a shaft 22 that is rotatably provided.
o. 1 to 23 test samples 30 (each test is provided) are provided. The mating shaft 21, the lower end 22A of the shaft, and the sample 30 are put into the lubricating oil 23, and the sample 30 is provided with the steel backing 4 facing upward and has a predetermined load WR (a constant load, a seizure test in a wear test). , A cumulative load according to time) is applied.

When a friction test is performed, a test sample 30 to be tested is provided between the mating shaft 21 and the lower end 22A of the shaft as described above, and the mating shaft 21 is rotated on the shaft 22 under the conditions of the wear test described above. The generated rotational power P is converted to the partner shaft 21 and the sample 3
It is detected by the frictional force detector 24 as a frictional force with zero. When performing the seizure test, the sample 30 to be tested is provided between the mating shaft 21 and the lower end 22A of the sample as described above. When the temperature of the portion (steel back metal 4) reaches the seizure determination reference temperature, the cumulative load WR applied at a rate of 10 kgf / 10 min is detected.

Sample No. The results of the wear test and the seizure test of Nos. 1 to 23 are shown in Table 1 below. No. Nos. 1 to 17 indicate test samples related to the present invention. Reference numerals 18 to 23 indicate comparative samples with the samples related to the present invention.

Sample No. Nos. 1 to 17 are comparative samples N which are general bearing materials used in conventional natural engines.
o. It can be seen that the seizure resistance is equal to or higher than that of No. 23 and the wear resistance is excellent.

The effect of the addition of Mo and W is shown in Comparative Sample No. Sample Nos. 18, 19, and 20
Comparison with 7, 8, 10, 11, 14, 15, 16, and 17 shows that seizure resistance and abrasion resistance are also excellent.
The effect of the addition of Bi is shown in Comparative Sample No. 21, 22 and the sample No. Comparison with 5, 7, 9 and 13 shows that both seizure resistance and abrasion resistance are effective.

The effect of adding P, Sn, Ni and Ag is as follows.
Sample No. No containing Sn, Ni and Ag 2 and Sample No. By comparison with 6, 7, 10, and 11, it can be seen that the seizure resistance is equal to or more than that and the abrasion resistance is excellent. Most of the friction of the bearing occurs at the time of initial wear until the bearing surface fits with the shaft, but the copper-based sintered sliding material of the present invention is Bi
It was found that the effect of the addition was such that the initial wear was terminated early and the total wear amount could be reduced.

In addition, since the fitting between the bearing surface and the shaft is completed at an early stage, the friction between the bearing surface and the shaft is stabilized, seizure resistance is improved, and Bi is hardly eluted from the copper sintered body 3 due to frictional heat. .

The copper-based sintered sliding material of the present invention has
% Of Mo and / or W, and 0.5 to 20% by weight of Bi, and the balance is substantially made of Cu, thereby realizing environmental friendliness not using Pb which is a lubricating component. It was possible to have abrasion resistance and seizure resistance equal to or higher than the conventional one.

Further, the copper-based sintered sliding material is 1 to 20.
% By weight of Mo and / or W and 0.5 to 20% by weight of Bi and 0.4% by weight or less of P,
The copper sintered body can be properly strengthened.

Further, the copper-based sintered sliding material is 1 to 20.
% By weight of Mo and / or W and 0.5 to 20% by weight of Bi, further containing up to 12% by weight of Sn,
Strengthening of copper sintered body and corrosion resistance can be improved accurately.

Further, the copper-based sintered sliding material is 1-20
% By weight of Mo and / or W and 0.5 to 20% by weight of Bi, and further containing 10% by weight or less of Ni,
Strengthening of copper sintered body and corrosion resistance can be improved accurately.

Further, the copper-based sintered sliding material is 1 to 20.
Since Mo and / or W by weight and 0.5 to 20% by weight of Bi further contain 5% by weight or less of Ag, the strengthening and corrosion resistance of the copper sintered body can be accurately improved.

Further, the copper-based sintered sliding material is 1 to 20.
Wt% Mo and / or W and 0.5-20 wt% Bi, plus 0.4 wt% or less of P, 12 wt%
Since it contains at least two of the following Sn, 10% by weight or less of Ni, and 5% by weight or less of Ag, the strengthening and corrosion resistance of the copper sintered body can be accurately improved. Furthermore, since the back metal is provided on the back surface of the copper-based sintered sliding material, the strength of the copper-based sintered sliding material can be reliably increased.

[0030]

[Table 1]

[Brief description of the drawings]

FIG. 1 schematically shows a cross section of a copper-based sintered sliding material according to the present invention.

FIG. 2 is a schematic view of a cylindrical flat plate friction and wear tester for performing a wear test and a seizure test.

[Explanation of symbols]

 Reference Signs List 1 Mo, W 2 Bi 3 Copper sintered base 4 Steel backing 20 Cylindrical flat plate friction and wear tester 21 Mating shaft 22 Shaft 23 Lubricating oil 24 Friction force detector 30 Sample

Claims (7)

[Claims] 1 to 20% by weight of Mo and / or W
And 0.5 to 20% by weight of Bi, with the balance substantially consisting of Cu. 2. The copper-based sintered sliding material comprises 1 to 20% by weight of Mo and / or W and 0.5 to 20% by weight of Bi.
2. The copper-based sintered sliding material according to claim 1, further comprising 0.4% by weight or less of P. 3. The copper-based sintered sliding material comprises 1 to 20% by weight of Mo and / or W and 0.5 to 20% by weight of Bi.
The copper-based sintered sliding material according to claim 1, further comprising 12% by weight or less of Sn. 4. The copper-based sintered sliding material comprises 1 to 20% by weight of Mo and / or W and 0.5 to 20% by weight of Bi.
2. The copper-based sintered sliding material according to claim 1, further comprising 10% by weight or less of Ni. 5. The copper-based sintered sliding material comprises 1 to 20% by weight of Mo and / or W and 0.5 to 20% by weight of Bi.
The copper-based sintered sliding material according to claim 1, further comprising 5% by weight or less of Ag. 6. The copper-based sintered sliding material comprises 1 to 20% by weight of Mo and / or W and 0.5 to 20% by weight of Bi.
In addition, 0.4% by weight or less of P, 12% by weight or less of Sn, 10% by weight or less of Ni, and 5% by weight or less of A
The copper-based sintered sliding material according to claim 1, comprising at least two of g. 7. The copper-based sintered sliding material according to claim 1, wherein a back metal is provided on a back surface.
The copper-based sintered sliding material according to any one of the above items.