JPH076543B2 - Slide bearing material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a slide bearing material used for a slide bearing or the like for an internal combustion engine.

[Prior Art] Conventionally, sliding bearings made of an aluminum alloy are often used in internal combustion engines of automobiles and the like. In recent years, along with the improvement in performance of automobile internal combustion engines, there has been a demand for sliding bearings capable of withstanding high-speed rotation and heavy loads. Further, from the requirement for maintenance-free engine oil, there is a demand for a high-performance sliding bearing having both good lubricity and corrosion resistance.

By the way, as a slide bearing material having the above-mentioned performance, a slide bearing material having an overlay layer containing lead as a main component on the surface of an aluminum bearing alloy is known. However, in the aluminum alloy bearing material having this overlay layer, it is known that it is difficult to maintain the performance for a long period of time due to the diffusion of the metal element from the overlay layer into the aluminum bearing alloy. Therefore, in order to prevent or suppress this problem, conventionally, as shown in FIG. 2, an intermediate layer 101 such as a nickel alloy is interposed between the overlay layer 100 and the aluminum alloy layer 102 so that the overlay layer 100 and the aluminum alloy layer are removed. A sliding bearing material that prevents the diffusion of elements into 102 is known.

[Problems to be Solved by the Invention] In the above-mentioned conventional sliding bearing material, since sufficient adhesion strength between the intermediate layer 101 and the aluminum alloy layer 102 cannot be obtained, the bearing environment under high speed rotation and high load is severe. However, there was a problem that the fatigue resistance was inferior when it was used.

The present invention has been made in view of such circumstances,
Improves the adhesion strength between the intermediate layer and the aluminum alloy layer,
The present invention provides a sliding bearing material that can withstand use under high load for a long period of time.

[Means for Solving Problems] As shown in FIG. 1, the sliding bearing material of the present invention includes a base material 1 and an aluminum alloy layer 2 formed on the surface of the base material 1.
And a overlay bearing layer 5 mainly composed of lead formed on the surface of the aluminum alloy layer 2, wherein a nickel or cobalt alloy is provided on the overlay layer 5 side between the aluminum alloy layer 2 and the overlay layer 5. Intermediate layer 4 made of a metal or alloy composed of at least one element selected from the group consisting of chromium, titanium and iron, and an element forming intermediate layer 4 between intermediate layer 4 and aluminum alloy layer 2. At least one kind of aluminum alloy layer 2
The bonding layer 3 is made of an alloy or an intermetallic compound containing at least one of the elements constituting

For the base material, the same materials as those conventionally used, such as carbon steel, can be used.

The aluminum alloy layer usually contains aluminum as a main component and contains 0.1 to 40% by weight of at least one element selected from tin, lead, silicon, bismuth, cadmium, indium, chromium, copper, magnesium, and magazine elements. It can be Where tin, lead, silicon,
The reason for adding bismuth, cadmium, and indium is to improve lubricity as a bearing, and chromium, copper,
The reason for adding magnesium, manganese, and silicon is to improve the mechanical strength of the bearing.

This aluminum alloy layer can be formed by, for example, thermocompression bonding an aluminum alloy layer previously formed with the above composition to the above base material. The thickness of this aluminum alloy layer can be generally 0.1 to 1 mm.

The overlay layer is mainly composed of lead, and has lubricity as a bearing,
In order to improve corrosion resistance, etc., generally 3 to
30% by weight of at least one element such as tin, indium and thallium is contained. Also, in order to improve the height of the overlay layer, 0.1-3% by weight of copper or 0.05
It can also contain up to 1.0% by weight of antimony. The appropriate thickness of this overlay layer is in the range of 2 to 30 μm. If the thickness of the overlay layer is less than 2 μm, wear and corrosion of the overlay layer will progress rapidly and the fatigue resistance of the bearing will be poor. Further, even if it is 30 μm or more, it does not contribute much to the improvement of the performance, which is disadvantageous in cost.

The intermediate layer is a metal or alloy composed of at least one element selected from nickel, cobalt, chromium, titanium and iron. This is because these elements have a good compatibility with the overlay layer containing lead as a main component, are easily compatible with the overlay layer when the intermediate layer is formed, and have excellent adhesion. The thickness of this intermediate layer is preferably in the range of 500 to 20000Å. If the thickness of the intermediate layer is less than 500Å, the film becomes non-uniform and defects such as pinholes are likely to occur, making it difficult to obtain uniform adhesion with the overlay layer. Also, 20
If the thickness is more than 000Å, internal stress may be generated in the film, causing defects such as peeling.

The bonding layer is composed of an alloy or an intermetallic compound containing at least one of the constituent elements of the intermediate layer and at least one of the constituent elements of the aluminum alloy layer.

The present inventors have found that in a sliding bearing material having an aluminum alloy layer, an overlay layer, and an intermediate layer between the aluminum alloy layer and the overlay layer, a bonding layer having a strong bonding force to both the intermediate layer and the aluminum alloy layer. It was considered to improve the adhesion between the intermediate layer and the aluminum alloy layer by interposing. Then, as a result of earnest research, by interposing a bonding layer containing at least one element contained in the intermediate layer and at least one element contained in the aluminum alloy layer, the bonding layer and the intermediate layer and the bonding layer and the aluminum alloy layer are provided. The inventors have found that a sufficient adhesion strength with can be obtained and completed the present invention.

The thickness of the bonding layer is preferably in the range of 50 to 1000Å. If the thickness of the bonding layer is less than 50Å, it will be difficult to obtain a uniform bonding layer, so that sufficient bonding force with the intermediate layer or the aluminum alloy layer cannot be obtained. On the other hand, if the thickness is more than 1000Å, the physical properties of the bonding layer become hard and brittle, and there is a possibility that the bonding layer may break during use under high load. When breakage occurs in the bonding layer, the adhesiveness with the intermediate layer and the aluminum alloy layer is reduced.

The method of forming each layer will be described below.

The aluminum alloy layer can be formed by thermocompression-bonding an alloy having a predetermined composition formed in a predetermined shape on the surface of the base material.

The bonding layer can be formed on the surface of the aluminum alloy layer by a wet plating method, a physical vapor deposition method (PVD method), a chemical vapor deposition method (CVD method), or the like. However, it is often difficult to form an alloy or an intermetallic compound, which is a material for the bonding layer, on the surface of the aluminum alloy layer by the above method, because of technical and cost reasons. Therefore, it is desirable to perform the method described below.

The method first forms an intermediate layer on the surface of the aluminum alloy layer. The intermediate layer can be formed by a PVD method, a CVD method, a wet plating method, or the like. Then, the aluminum alloy layer having the intermediate layer is heat-treated in the temperature range of 250 to 450 ° C. This heat treatment promotes mutual diffusion of the constituent elements of the intermediate layer and the constituent elements of the aluminum alloy layer,
It is a method of forming a bonding layer composed of an alloy or a metal compound containing at least one of the constituent elements of the intermediate layer and at least one of the constituent elements of the aluminum alloy layer. In this case, if the heat treatment temperature is lower than 250 ° C., mutual diffusion between the element of the intermediate layer and the element of the aluminum alloy layer is difficult to occur, so that the bonding layer having a sufficient thickness cannot be formed. Further, if the heat treatment temperature is higher than 450 ° C, the bonding layer becomes too thick.

The overlay layer can be formed on the surface of the intermediate layer by a wet plating method or the like. Further, in order to improve the adhesion between the overlay layer and the intermediate layer, the overlay layer is thinly formed on the surface of the intermediate layer in advance by the PVD method. After that, it is also desirable to further form the overlay layer by a wet plating method so as to have a predetermined thickness.

[Operation and Effect of the Invention] The plain bearing material of the present invention has a bonding layer between the intermediate layer and the aluminum alloy layer. The bonding layer is made of an alloy or a metal compound containing at least one constituent element of the intermediate layer and at least one constituent element of the aluminum alloy layer. Therefore, the bonding layer thus configured has good compatibility with both the intermediate layer and the aluminum alloy layer, is well compatible with the bonding layer when it is formed, and has excellent adhesion.

Therefore, since the slide bearing formed of the slide bearing material of the present invention has excellent adhesion between the intermediate layer and the aluminum alloy layer, the fatigue resistance as a bearing even under a severe bearing environment of high speed rotation and high load Is improved. Moreover, the bonding layer can be easily formed by simply heat-treating it after forming the intermediate layer, and can be manufactured almost in the same manner as the conventional one.

[Examples] Specific examples will be described below.

(Embodiment 1) FIG. 1 shows the configuration of a first embodiment of the present invention. This plain bearing material consists of base material 1 made of SPCC steel and SAE standard No.780.
An aluminum alloy layer 2 made of (Al-6.5Sn-1.5Si-1.0Cu (wt%)) and having a thickness of 0.3 mm, which is thermocompression bonded to the surface of the base material 1, and an Al-Ni layer formed on the surface of the aluminum alloy layer 2. A bonding layer 3 made of an alloy and having a thickness of 100Å, and an intermediate layer 4 formed on the surface of the bonding layer 3 and made of nickel and having a thickness of about 5000Å
And an overlay layer 5 made of Pb-10Sn-5In (wt%) and having a thickness of 5 μm formed on the surface of the intermediate layer 4.

The method of forming the plain bearing material will be described below. First, the aluminum alloy layer 2 is thermocompression bonded to the base material 1. Then, the nickel intermediate layer 4 is formed on the surface of the aluminum alloy layer 2 by the sputtering method to a thickness of 5000 Å. Next, in air, the base material having the intermediate layer 4 formed on the aluminum alloy layer 2 is heat-treated at 300 ° C. for 1 hour to form a bonding layer. Next, the surface oxide layer of the intermediate layer 4 was removed by etching, and the overlay layer 5 was formed by a wet plating method or the like to obtain the sliding bearing material of this example. The binding layer 3 was identified by X-ray diffraction and depth direction analysis using an Auger electron analyzer. FIG. 3 shows a schematic view of the result of the depth direction analysis by the Auger electronic analyzer. It is apparent from FIG. 3 that the bonding layer 3 is formed between the intermediate layer 4 and the aluminum alloy layer 2.

Next, an adhesion evaluation test and a fatigue resistance test of the slide bearing material obtained as described above were carried out. The adhesion evaluation test is excellent, good, or poor by observing the broken surface with a scanning electron microscope (SEM).
A 4-grade evaluation of yes and no was performed visually. The fatigue resistance test was carried out under the following test conditions, and the time T at which fatigue occurred was evaluated.

Test conditions Tester: Reciprocating load tester Rotation speed: 2000 rpm Surface pressure: 300 ± 40 kg / cm ² Lubricating oil: SAE10w-30 Lubrication temperature: 110 ± 5 ° C Shaft material: S55C quenching (Hv = 500-600) Shaft Roughness: 0.4 to 0.6 μm Rz The test results are shown in the table.

(Examples 2 to 8) The sliding bearing materials of Examples 2 to 8 were formed in the same manner as in Example 1 except that the material of the intermediate layer and / or the heat treatment temperature was changed. The forming conditions and the composition of the bonding layer are shown in the table. Then, an adhesion test and a fatigue resistance test were conducted in the same manner as in Example 1, and the results are shown in the table.

(Comparative Example) A sliding bearing material of a comparative example was obtained in the same manner as in Example 1 except that heat treatment was not performed. The sliding bearing material of this comparative example was also subjected to the adhesion evaluation test and the fatigue resistance test in the same manner as in Example 1, and the results are shown in the table. It is to be noted that FIG. 4 shows a schematic diagram of the results of the depth direction analysis of the sliding bearing material of the comparative example by the Auger electronic analyzer. As is clear from FIG. 4, the sliding bearing material of the comparative example has no bonding layer formed.

(Evaluation) As is clear from the table, the sliding bearing materials of the examples of the present invention are superior to the sliding bearing materials of the comparative examples in terms of the results of the adhesion evaluation test and the fatigue resistance test. It is clear that this is due to the effect that the coupling layer is formed in the sliding bearing material of the embodiment.

[Brief description of drawings]

FIG. 1 is a sectional view of a plain bearing material according to a first embodiment of the present invention. FIG. 2 is a sectional view of a conventional plain bearing material. FIG. 3 is a diagram showing the outline of the depth direction analysis result of the plain bearing material of Example 1 by the Auger electron analyzer. Fourth
The figure is a diagram showing an outline of the depth direction analysis result of the sliding bearing material of the comparative example by the Auger electronic analyzer. 1 ... Substrate, 2 ... Aluminum alloy layer 3 ... Bonding layer, 4 ... Intermediate layer 5 ... Overlay layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Kumada 3-65 Midorigaoka, Toyota-shi, Aichi Otoyo Kogyo Co., Ltd. (72) Inventor Shoji Kamiya 3-65 Midorigaoka, Toyota-shi, Aichi Otoyo Kogyo Co., Ltd. In-house (72) Inventor Yuji Yokota 3-65 Midorigaoka, Toyota-shi, Aichi Otoyo Kogyo Co., Ltd. (56) Reference JP-A-60-166183 (JP, A) JP-B-52-30656 (JP, B2) )

Claims (3)

[Claims] 1. A slide bearing material comprising a base material, an aluminum alloy layer formed on the surface of the base material, and an overlay layer containing lead as a main component formed on the surface of the aluminum alloy layer, wherein the aluminum alloy. An intermediate layer made of a metal or alloy composed of at least one element selected from nickel, cobalt, chromium, titanium and iron on the overlay layer side between the layer and the overlay layer; and the intermediate layer. And a bonding layer made of an intermetallic compound containing at least one of the elements forming the intermediate layer and at least one of the elements forming the aluminum alloy layer are interposed between the aluminum alloy layer and the aluminum alloy layer. Sliding bearing material characterized by 2. The sliding bearing material according to claim 1, wherein the thickness of the bonding layer is 50 to 1000Å. 3. A plain bearing material according to claim 1, wherein the intermediate layer has a thickness of 500 to 20000Å.