JPH09202932A - Sliding member made of al alloy and plain bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a sliding member made of an Al alloy capable of obtaining antinomic characteristics of fatigue resistance and surface performance on the higher standards which can not be attained heretofore and to produce a plain bearing. SOLUTION: This is a sliding member made of an Al alloy obtd. by laminating an Al-Zn-Mg base Al alloy I contg., by weight, 4.0 to 5.5% Zn and 0.5 to 2.5% Mg with an Al-Sn-Pb, Sb-Si-Cu, Cr base Al alloy II contg. one or two kinds of 8 to <15% Sn, one or two kinds selected from among Pb and Sb by 0.5 to 10%, 0.1 to 4.5% Si, one or >= two kinds selected from among Cu and Cr by 0.1 to 3.0%. Furthermore, a plain bearing made of an Al alloy obtd. by furthermore laminating a back plate (such as a steel plate) according to necessary is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to Al suitable as a material for bearings and sliding members used as structural parts of various mechanical devices such as automobiles, machine tools and agricultural machines.
The present invention relates to an alloy sliding member and a slide bearing.

[0002]

2. Description of the Related Art Recently, as a bearing alloy for an internal combustion engine, an Al-based bearing alloy has been attracting attention from the viewpoints of heat resistance, wear resistance, corrosion resistance, fatigue resistance, seizure resistance, etc. Its usage is increasing rapidly.

[0003]

However, Al-based bearing alloys with Kelmet (mild steel base metal with a thickness of about 1 mm and high lead bronze (Pb 20-45 wt%).
In order to have the same level of fatigue resistance as the trade name of bearings backed by Cu alloys), including that of Kelmet, or Sn.
It is necessary to reduce the amount of soft components such as Pb and Pb, but in that case, since the seizure resistance is lowered, it was necessary to form a Pb-Sn-based overlay layer on the surface like Kermet.

However, in the high speed and high load range, Pb-S
It was confirmed by experiments that those having an n-based overlay layer on the surface exhibit a marked increase in friction than the surface layer of an Al-based bearing alloy having good thermal conductivity.

According to the conventional wisdom, in the high-speed and high-load range, when the temperature of the lubricating oil becomes high, the oil viscosity decreases and the oil film becomes thin, and as a result, the friction as the shearing resistance of the oil decreases. At this time, it has been said that the difference in bearing material has no effect.

As a result of some research conducted by the present inventors on the frictional behavior of the bearing when the temperature of the lubricating oil becomes high, the viscosity decreases as the temperature of the oil becomes high, and the oil film However, it was found that the oil film pressure was increased, and as a result, the oil viscosity under high pressure was significantly increased, which in turn increased the friction as the shear resistance of the oil. Further, under such a condition, the local high oil film pressure naturally impairs the fatigue resistance of the bearing.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and it is effective to lower the temperature of the oil film, which is the starting point of the mechanism, in order to reduce friction in a high speed / high load range. For that purpose, it is important to increase the thermal conductivity of the bearing alloy layer, which is also irrelevant in the past, which also plays a role of quickly removing the local heat generation of the intervening oil. It is based on something.

By making the bearing alloy have high thermal conductivity, the friction loss in the lubricating oil in the high speed / high load range can be greatly reduced as compared with the conventional slide bearing.

Further, in addition to improving the strength of the bearing alloy, by using the bearing of the present invention having high thermal conductivity to reduce the intervening oil film pressure, the fatigue resistance is improved and the surface performance is at a level unprecedented. Can be achieved with.

Therefore, an object of the present invention is to provide a sliding member and a slide bearing made of an Al--Sn alloy which can obtain both anti-fatigue properties such as fatigue resistance and surface performance at an unprecedented high level. To do.

[0011]

Al-S according to the present invention
As described in claim 1, the n-based alloy sliding member has a weight ratio of Zn: 4.0 to 5.5% and Mg: 0.5.
Al-Zn-Mg-based Al alloy I containing ~ 2.5%, and Sn: 8-15% by weight, one or two kinds selected from Pb and Sb: 0.5-10%. , Si: 0.
1 to 4.5%, one or two selected from Cu and Cr: Al-Sn-Pb, S containing 0.1 to 3.0%
It is characterized in that it is configured by laminating b-Si-Cu, Cr-based Al alloy II.

The Al alloy slide bearing according to the present invention is
%, Zn: 4.
Al-Z containing 0 to 5.5% and Mg: 0.5 to 2.5%
n-Mg-based Al alloy I and Sn: 8 to less than 15% by weight, and one or two selected from Pb and Sb:
0.5-10%, Si: 0.1-4.5%, Cu, Cr
1 type or 2 types selected from among: 0.1 to 3.0%
Al-Sn-Pb, Sb-Si-Cu, Cr-based A containing
It is characterized in that it is configured by laminating the 1-alloy II.

[0013]

As described in claims 1 and 2, the Al alloy sliding member and the sliding bearing according to the present invention have a weight ratio of Zn: 4.0 to 5.5% and Mg: 0.5
Al-Zn-Mg-based Al alloy I containing ~ 2.5%, and Sn: 8-15% by weight, one or two kinds selected from Pb and Sb: 0.5-10%. , Si: 0.
1 to 4.5%, one or two selected from Cu and Cr: Al-Sn-Pb, S containing 0.1 to 3.0%
The structure is made by stacking b-Si-Cu, Cr-based Al alloy II, and the reasons for limiting the respective components and numerical values will be described below together with the action of each element.

First, the reasons for limiting the components and numerical values of the Al-Zn-Mg Al alloy I will be explained together with the action of each element.

(I-1) Zn: 4.0-5.5% Zn is an element effective for increasing the strength of the Al alloy, but if it is less than 4.0%, its effect is small and 5.5%. When it exceeds 4.0, workability such as rolling is deteriorated, so 4.0 to 5.
5%.

(I-2) Mg: 0.5 to 2.5% Mg is an element effective for increasing the strength of the Al alloy, but if it is less than 0.5%, its effect is small and 2.5%. If it exceeds 1.0, the workability such as rolling decreases, so 0.5-2.
5%.

(I-3) One or more selected from Cu, Cr and Mn: 0.1 to 2.5% Cu, Cr and Mn are effective elements for increasing the strength of the Al alloy. Therefore, one kind or two or more kinds of these may be contained as necessary. In this case, if the total amount of these is less than 0.1%, there is no effect, and if it exceeds 2.5%, the mechanical properties, in particular elongation, are reduced, so even if it is contained, it should be 0.1-2.5%. good.

Next, Al-Sn-Pb, Sb-Si-C
The reasons for limiting the components and numerical values of u, Cr-based Al alloy II will be described together with the action of each element.

(II-1) Sn: 8 to less than 15% One or two selected from Pb and Sb: 0.5
-10% Sn, Pb, Sb are effective elements as a lubricating component,
It has excellent seizure resistance. Further, when the alloy II is used as the surface layer, the compatibility and the foreign matter embedding property are enhanced.

However, when Sn is less than 8% and the total amount of Pb and Sb is less than 0.5%, the effect is small, and Sn is 15%.
As described above, when the total amount of Pb and Sb exceeds 10%, the thermal conductivity decreases, and the increase of friction loss in high temperature lubricating oil, which is one of the features of the sliding member and the sliding bearing of the present invention, is suppressed. Sn is less than 8-15%, P
The total of one or two selected from b and Sb was 0.5 to 10%.

(II-2) Si: 0.1 to 4.5% Si contributes to the improvement of seizure resistance when alloy II is used as the surface layer, but if it is less than 0.1%, its effect is small. 4.
If it exceeds 5%, the conformability and the workability such as rolling decrease, so 0.1 to 4.5% was set.

(II-3) One or two selected from Cu and Cr: 0.1 to 3.0% Cu and Cr are load-bearing when alloy II is used as the surface layer,
Although heat resistance is improved, if it is less than 0.1%, its effect is small, and if it exceeds 3.0%, the conformability and workability such as rolling deteriorate, so it was made 0.1 to 3.0%.

The Al alloy sliding member and the sliding bearing according to the present invention have the above-mentioned composition, but Ti, Sr, B, Zr and C which are crystal grain refining elements of the Al alloy.
a, REM (one or more rare earth elements including Y and Sc) or the like may be added, or Ni, V, Fe, Co and the like which are strengthening elements of the Al alloy may be added as necessary. Of course good things.

Next, with respect to the method for producing the alloy II which can be used as the surface layer in the Al alloy sliding member and the sliding bearing according to the present invention, usually, a plate-shaped casting material is rolled. However, if Pb exceeds 4%, segregation occurs in the casting method and it is difficult to form a uniform material structure. Therefore, the plate material may be formed by powder rolling or sintering, or alloy I
When the alloy is used as the second layer and the alloy II is used as the surface layer, it can be directly laminated on the alloy I by thermal spraying.

And for alloy I and alloy II,
If necessary, heat treatment for strain removal can be performed.

The Al alloy slide bearing according to the present invention may have a structure in which the Al alloy II, the Al alloy I and the back metal are laminated. By using the plain bearing, it is possible to obtain both anti-fatigue resistance and surface performance, which are trade-off characteristics, at a high level that has never been achieved.

In this case, by using a steel plate as the back metal, the bearing has rigidity required for the bearing.

[0028]

Next, examples will be described together with comparative examples.

Examples 1 to 4 and Comparative Examples 1 to 3 First, Al-Sn alloys having the compositions of Examples 1 to 4 and Comparative Examples 1 to 3 shown in the column of alloy II in Table 1 were thickened by continuous casting. It is cast as a plate with a thickness of 20 mm, the upper and lower surfaces of each casting billet are cut by 1 mm, and then cold rolled to 1 m.
It was rolled down to a thickness of m. In this state, heat treatment was performed at 200 to 300 ° C. to remove strain.

Next, Al-having the compositions of Examples 1 to 4 and Comparative Examples 1 to 3 shown in the column of this alloy II and alloy I of Table 1 were used.
Each of the Zn-Mg-based alloys and rolled material having a thickness of 8 mm was clad after cleaning the contact surface, and then 1 mm by cold rolling.
To the thickness of.

After this laminated material was annealed, alloy I was used as the second layer and alloy II was used as the surface layer on the steel plate that served as the back metal. Subsequently, the surface is further mechanically removed, so that the thickness of the steel plate as the back metal is about 1.20.
mm, the layer thickness of the alloy I was about 0.25 mm, the layer thickness of the alloy II was about 0.05 mm, and a total thickness of about 1.5 mm was obtained.

Comparative Example 4 Al-having the composition of Comparative Example 4 shown in the column of alloy I in Table 1
A Sn-based alloy was cast as a plate-shaped material having a thickness of 20 mm by continuous casting, the upper and lower surfaces of the cast billet were cut by 1 mm, and then cold rolled to reduce the thickness to 8 mm. In this state, heat treatment was performed at 200 to 300 ° C. to remove strain.

Next, Comparative Example 4 shown in the column of Alloy II in Table 1
An Al-Sn alloy having the composition of No. 1 was cast by continuous casting as a plate material having a thickness of 20 mm, the upper and lower surfaces of the cast billet were cut by 1 mm, and then cold-rolled to a thickness of 1 mm. In this state, a heat treatment at 200 to 300 ° C. was performed to remove the strain.

Next, the contact surfaces of the two alloys I and II were cleaned, clad, and then 1 mm.
Cold rolled to a thickness of

After this laminated material was annealed, alloy I was used as the second layer and alloy II was used as the surface layer on the backing steel plate. Subsequently, the surface is further mechanically removed, so that the thickness of the steel plate as the back metal is about 1.20.
mm, the layer thickness of the alloy I was about 0.25 mm, the layer thickness of the alloy II was about 0.05 mm, and a total thickness of about 1.5 mm was obtained.

Comparative Example 5 Comparative Example 5 shown in the column of alloy II in Table 1 (same as Example 1)
An Al-Sn alloy having the composition of No. 1 was cast by continuous casting as a plate material having a thickness of 20 mm, the upper and lower surfaces of each cast billet were cut by 1 mm, and then cold-rolled to a thickness of 1 mm. In this state, a heat treatment at 200 to 300 ° C. was performed to remove the strain.

After that, the alloy II was clad on the steel plate serving as the backing metal, and the surface was mechanically removed. As a result, the thickness of the steel plate serving as the backing metal was about 1.2 mm and the alloy II serving as the surface layer was formed. Layer thickness is about 0.3 mm and total thickness is about 1.5
A plain bearing of mm was obtained.

Comparative Example 6 An Al—Zn—Mg-based alloy having the composition of Comparative Example 6 (same as Example 1) shown in the column of alloy I in Table 1 was rolled to a thickness of 1 mm and heat-treated at 200 to 300 ° C. Was performed to remove the strain.

After that, the alloy I is clad on the steel plate as the backing metal, the surface is mechanically removed, and the surface is pretreated by degreasing or the like, and then zinc substitution treatment is performed, and electroless nickel plating is performed. About 1 μm and 10% by weight on it
2 Pb-Sn-Cu plating containing Sn and 2 wt% Cu
It was applied to a thickness of 0 μm.

As a result, the thickness of the steel plate as the back metal is about 1.2 mm, and the layer thickness of alloy I as the surface layer is about 0.3.
A plain bearing having a total thickness of about 1.5 mm in mm was obtained.

Comparative Example 7 An alloy consisting of 25 wt% Pb, 3 wt% Sn and the balance substantially Cu (a Kelmet compatible alloy) was melted and continuously poured onto a steel sheet, and immediately after the pouring, the steel sheet was poured. Cu-P with dendrite structure on the steel plate
The material which laminated the b-Sn alloy was produced. Then, after further dimension adjustment, electroless nickel plating is applied to a thickness of 1 μm, and Pb—Sn—Cu plating containing 10 wt% Sn and 2 wt% Cu is applied thereon to a thickness of 20 μm to obtain a total thickness. A plain bearing having a size of about 1.5 mm was obtained.

[0042]

[Table 1]

(Seizure resistance test) Examples 1 to 4 and Comparative Example 1
From each slide bearing obtained in ~ 7, width 35mm, length 35m
A test piece of m was cut out, and a seizure resistance test was performed under the conditions shown in Table 2 using a ring-on-plate type Suzuki abrasion tester. Table 3 shows the results.

[0044]

[Table 2]

[0045]

[Table 3]

As is clear from Table 3, Example 1 of the present invention
It can be seen that the slide bearings Nos. 4 to 4 have seizure resistance equivalent to or higher than that of the slide bearings of Comparative Examples 6 and 7, which have been considered to be more excellent in seizure resistance than before.

On the other hand, it is clear that the sliding bearings of Comparative Examples 1 and 2 in which the component of the alloy II as the surface layer is out of the present invention are inferior in seizure resistance to the sliding bearings of the examples of the present invention.

(High Temperature Friction) Examples 1 to 4, Comparative Example 6,
Each plain bearing obtained in No. 7 was processed into a half bearing shape, and a bearing unit testing machine developed by some of the inventors (Japan Society of Mechanical Engineers)
Proceedings of the 71st National Convention vol. D, 1993, p. 332-334), the frictional force when the sliding surface became high temperature was measured under the conditions shown in Table 4. Sliding surface is 1
Table 5 shows the friction torque at 30 ° C.

[0049]

[Table 4]

[0050]

[Table 5]

As is clear from Table 5, Example 1 of the present invention
It can be seen that the slide bearings of Nos. 4 to 4 have better abrasion resistance than the slide bearings of Comparative Examples 6 and 7 having the Pb-Sn-Cu overlay layer on the surface.

(Fatigue Resistance Test) Examples 1 to 4 and Comparative Examples 1 to 1
Each slide bearing obtained in No. 6 was processed into a half bearing shape so as to be applied as an engine part, and an underwood test was conducted under the conditions shown in Table 6. Table 7 shows the results.

[0053]

[Table 6]

[0054]

[Table 7]

As is clear from Table 7, the sliding bearings of Comparative Examples 3 and 4 in which the alloy composition of the second layer (alloy I) deviates from the present invention and Comparative Example 5 in which the second layer (alloy I) is not provided,
Fatigue resistance is inferior to the sliding bearings of the examples.

Even if the alloy composition of the second layer (alloy I) satisfies the present invention, the alloy composition of the surface layer (alloy II) is out of the invention as in Comparative Examples 1 and 2. The slide bearing is inferior in fatigue resistance to the slide bearings of the examples.

From these three kinds of test results, it is clear that the sliding bearing according to the present invention simultaneously achieves seizure resistance, fatigue resistance and reduction of friction loss in high temperature lubricating oil, and it is clear that various conventional sliding bearings are used. It was found that the bearing alloy had performances that were impossible.

[0058]

As described above, the Al alloy sliding member and the sliding bearing according to the present invention, as described in claims 1 and 2, have a Zn:
Al containing 4.0 to 5.5% and Mg: 0.5 to 2.5%
-Zn-Mg-based Al alloy I and Sn: 8 to 1 by weight%
Less than 5%, one or two selected from Pb and Sb
Species: 0.5-10%, Si: 0.1-4.5%, Cu,
One or two selected from Cr: 0.1-3.
Al-Sn-Pb, Sb-Si-Cu, Cr containing 0%
Since it is configured by laminating the system Al alloy II, both anti-fatigue properties of surface resistance and fatigue resistance are realized at a high level that has never been achieved in the past. The remarkable effects that the improvement of the fatigue resistance due to the improvement of the lubrication performance and the suppression of the oil film temperature rise due to the improvement of the heat removal property of the bearing alloy are extremely superior to the conventional sliding member and the sliding bearing are brought about.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shunichi Aoyama 2 Takaracho, Kanagawa-ku, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Ken Ushijima 2 Takara-cho, Kanagawa-ku, Yokohama Kanagawa Within the corporation

Claims (2)

[Claims] 1. Zn: 4.0 to 5.5% by weight, M
g: Al-Zn-Mg-based Al alloy I containing 0.5 to 2.5%, and Sn: 8 to less than 15% by weight, one or two selected from Pb and Sb: 0 0.5-10%, Si:
Al-Sn-P containing 0.1 to 4.5%, one or two selected from Cu and Cr: 0.1 to 3.0%
b, Sb-Si-Cu, Cr-based Al alloy II is laminated to form an Al alloy sliding member. 2. Zn: 4.0 to 5.5% by weight, M
g: Al-Zn-Mg-based Al alloy I containing 0.5 to 2.5%, and Sn: 8 to less than 15% by weight, one or two selected from Pb and Sb: 0 0.5-10%, Si:
Al-Sn-P containing 0.1 to 4.5%, one or two selected from Cu and Cr: 0.1 to 3.0%
A slide bearing made of Al alloy, characterized by being formed by laminating b-, Sb-Si-Cu, and Cr-based Al alloy II.