JPH05320681A - Composite sliding material containing solid lubricant and its production - Google Patents

Abstract

PURPOSE:To obtain a sliding material which has a low coefficient of friction and a low specific wear rate, is excellent in mechanical properties, and can be used in any atmosphere by forming from a specified lubricating member layer provided on the sliding surface and a backing metal layer joined thereto. CONSTITUTION:A sliding material consists of a lubricating member layer provided on the sliding surface to be in contact with a sliding or rolling member, and a backing metal layer joined thereto, which comrises a composite sliding material containing a solid lubricant wherein the lubricating member layer has a thickness of 0.1-10mm and contains 5-95wt.% solid lubricant comprising one or both of WS2 and MoS2 having a particle diameter of 1-500mum, with the remaining bonding part comprising a sintered phase containing 0.05-2.0wt.% boron and a metal or alloy powder containing at least one of Ni, Fe, Cr, Mo, W, Ta, Co, Sn and Cu. If heat resistance is required, the amount of Fe, Cr, Ni, Mo, etc., is increased or an alloy thereof is used, and for electrical conductivity, Cu, Sn, etc., are used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-lubricated composite sliding material suitable for use in bearings or sliding parts as various machine parts.

[0002]

_2. Description of the Related Art Conventionally, tungsten disulfide (WS ₂ ),
Sintered bodies made of molybdenum disulfide (MoS ₂ ), graphite, graphite fluoride, calcium fluoride, and various other metals and alloys are used as self-lubricating materials.

Typical examples of these conventional self-lubricating materials are disclosed in Japanese Patent Laid-Open Nos. 53-122059 and 62-196351.

A self-lubricating material composed of a lubricating substance such as tungsten disulfide and molybdenum disulfide and a binder phase of various metals and alloys is a starting material powder as a lubricating substance and a starting material powder as a binder phase. After mixing, molding, and sintering, the lubricating substance in the sintered body thus obtained reacts with the metal and alloy of the binder phase and changes to a non-lubricating substance, reducing its yield. However, there is a problem that the self-lubricating material is increased in wear and strength, and the life is remarkably reduced.

Therefore, if the content of the lubricating substance is increased in order to increase the yield of the lubricating substance, the strength of the sintered body is lowered, the workability of the sintered body is extremely lowered, and a high load is applied. It is difficult to use for sliding parts.

[0006]

DISCLOSURE OF THE INVENTION The present invention has solved the above-mentioned problems, and has a low coefficient of friction and a low specific wear rate, excellent mechanical properties, and is a solid that can be used in any atmosphere. An object is to provide a lubricated composite sliding material and a method for manufacturing the same.

[0007]

DISCLOSURE OF THE INVENTION In the present invention, as a result of studying reactivity, wettability, sinterability, etc. of a lubricating substance and a binder phase metal or alloy in a self-lubricating material, the results are shown as follows. The present invention has been completed by forming a dense compound phase between layers.

That is, the present invention is a sliding material comprising a lubricating member layer on a sliding surface in contact with a sliding member or a rolling member, and a back metal layer bonded to the lubricating member layer, wherein the lubricating member layer has a thickness of 0.1 to 10. Solid lubricants WS ₂ and MoS ₂ having a particle diameter of 1 μm or more and 500 μm or less at 10 mm are used alone or in combination with each other.
Included in the range of not less than 95 percent by weight and not more than 95 percent by weight, and the remaining bonding portion is Ni, Fe, Cr, Mo, W, Ta, C.
Solid-lubricated composite sliding characterized by being a sintered phase containing a metal or alloy powder containing one or more of O, Sn and Cu and 0.05 wt% or more and 2.0 wt% or less B. It is a material.

Tungsten disulfide and molybdenum disulfide are scaly powders having a particle size of 1 to 2 μm and are substances having a low friction coefficient in vacuum.

However, in an atmosphere with water, the coefficient of friction is high and the reactivity with metals is high. When mixed with metal powder and heated, it decomposes or changes into other sulfides. The extremely low yield in alloys makes the production of metal-based composites containing tungsten disulfide and molybdenum disulfide difficult.

Therefore, the material currently in practical use is 1
55-80, which is obtained by granulating scaly tungsten disulfide and molybdenum disulfide having a particle size of ˜2 μm to several tens of μm or more.
T, which is a metal that is relatively difficult to react with volume percent
A, W, Cu and Ag are selected and compounded.

Therefore, the strength of the sintered body is low, the workability is poor, and it cannot be used in a place where a high load is applied.

Therefore, as a result of studying a structure in which a lubricating member having a high lubricity is used for the sliding surface and the strength is provided by a metal member of the backing metal, the problem of this structural material is that the joining property of both members. I understood.

Therefore, as a result of further detailed examination of the wettability, reactivity and sinterability between the lubricating substance and the metal or alloy of the binder phase, the formation of a dense compound phase having a strong bonding force between both members. Was able to solve the problem.

That is, by adding B to a mixture of tungsten disulfide and molybdenum disulfide which are solid lubricants and a metallic binder phase such as Fe, Cr and Ni, a fine sulfurization between the lubricating member and the metal member of the back metal is performed. It turned out that things were produced.

With such a generated phase, it is possible to produce a sintered body having high mechanical strength and excellent lubricity in all atmospheres from the atmosphere to the vacuum and at high temperature.

[0017]

The solid-lubricated composite sliding material of the present invention has excellent sliding characteristics with a significantly low specific wear rate and wear coefficient due to the lubricating member containing a lubricating substance as a main component, and high strength due to the metal member. It is a bearing member that can be used in air or vacuum up to high temperatures.

That is, the solid lubricating composite sliding material of the present invention is a sliding material comprising a lubricating member layer on a sliding surface in contact with a sliding or rolling member, and a back metal layer bonded to the lubricating member layer. WS ₂ , Mo, which is a solid lubricant having a thickness of 0.1 to 10 mm and a particle size of 1 μm or more and 500 μm or less
S ₂ alone or in combination of 5 weight percent or more and 95 weight percent or less, and the remaining binding portion has a particle size of 100 μm.
Ni, Fe, Cr, Mo, W, Co, Sn, T of m or less
The solid lubricating composite sliding material is characterized by containing a metal or alloy powder containing one or more of a and Cu and 0.05 wt% or more and 2.0 wt% or less B.

The lubricating member layer containing WS ₂ and MoS ₂ as solid lubricants has poor lubricity when the ratio of WS ₂ and MoS ₂ alone or both is less than 5% by weight, resulting in a significantly high friction coefficient. ..

On the other hand, if it exceeds 95% by weight, the sinterability is poor and only a sintered body having extremely low strength can be produced.

Therefore, WS ₂ and MoS ₂ as the solid lubricants are singly or in the range of 5% by weight to 95% by weight. Desirably 30 weight percent or more 85
Not more than weight percent.

The solid lubricants WS ₂ and MoS ₂ have a particle size of 1 μm.
If it is less than m, the reaction with the metal is severe and the quality is easily changed.
If it exceeds 00 μm, the mixture with the metal powder becomes non-uniform and a homogeneous composite material cannot be obtained. Therefore, the thickness is set to 1 μm or more and 500 μm or less.

If the thickness of the lubricating member layer is less than 0.1 mm, the service life due to abrasion is short. Further, when the lubricating member layer is worn by several mm, the clearance between the lubricating member layer and the mating member becomes too large and it cannot be used. Therefore, 0.1-10 mm
And It is preferably 0.2 to 5 mm.

The rest of the lubricating material is Ni, Fe, Cr,
It is a binder phase using one kind or two or more kinds of metal or alloy powder of Mo, W, Ta, Co, Sn, Cu.

Ni, Fe, Cr, Mo, W and Ta are WS
₂ , which reacts with MoS ₂ to form a sulfide with rich lubricity and also has the function of firmly binding the lubricating substance and the metal, and Co, Sn, and Cu do not easily react with the lubricating substance and It has the effect of increasing the yield of substances.

It is desirable that the compounding composition of the binder phase of these metal or alloy powders be changed according to the purpose of use of the composite material.

When heat resistance is required, Fe, Cr, N
Increase the compounding amount of i, Mo, Co or the like, or use an alloy thereof, and use Cu, Sn or the like for the electrical conductivity.

Further, a metal such as W or Ta is used to suppress the reactivity with the lubricating substance.

If the particle size of the metal or alloy powder forming these binder phases exceeds 100 μm, the mixing with the lubricating substance becomes non-uniform, so 100 μm or less is desirable.

The bondability between the lubricating member layer and the back metal layer is a problem because WS ₂ and MoS ₂ of the solid lubricant react with the metal of the back metal layer to form a brittle compound.

Then, the reaction between the solid lubricants WS ₂ and MoS ₂ and the metal and the sinterability were carefully studied, and it was found that a small amount of boron (B) solves the problem.

That is, B forms a complex sulfide containing dense B between WS ₂ and MoS ₂ of the solid lubricant and the metal.

This sulfide forms a sintered body having high strength and strongly bonds the lubricating member layer and the back metal layer.

If the amount of B is less than 0.05 weight percent, no complex sulfide is formed, and if it exceeds 2.0 weight percent, a compound having a low melting point is formed.

Therefore, the amount of B added to the lubricating member layer should be 0.
It was set to be not less than 05 weight percent and not more than 2.0 weight percent.

The metal of the back metal layer is selected according to the purpose. Carbon steel and alloy steel are suitable when high strength is required, stainless steel, nickel alloy and titanium alloy are used when heat resistance and corrosion resistance are required, and copper alloy is used when electrical conductivity is required. Is good.

In the method for manufacturing the solid lubricating composite material bearing member of the present invention, the composition thereof contains solid lubricants WS ₂ and MoS ₂ alone or both in an amount of 5 to 95% by weight, and the rest of the joint portion is formed. 100μ particle size
Ni, Fe, Cr, Mo, W, Ta, Co, S of m or less
Pressed a metal or alloy powder containing one or more of n and Cu, a mixed powder containing 0.05 to 2.0 wt% of B, and a metal powder or a metal powder mixture to be a back metal layer. After being filled in the mold so as to form a layer in the direction parallel to or perpendicular to the direction, press molding is performed to obtain a molded product having a desired shape.

The molded body is sintered in a temperature range of 700 ° C. to 1200 ° C. in a non-oxidizing atmosphere.

By sintering, the back metal layer and the lubricating member layer are firmly bonded to each other to produce a solid lubricating composite sliding material having both lubricity and strength.

Furthermore, a solid lubricating composite sliding material is produced by laminating or separately molding a lubricating member layer and a back metal layer, or by adhering them by fitting or the like to form an integral body and then sintering. You can

The coefficient of expansion of the lubricating member layer containing the solid lubricant upon sintering is slightly higher than that of the metal back metal layer.

Therefore, as shown in FIG. 1, when the sliding surface is the inner surface of a cylindrical member, the back metal layer 2 is used as the outer cylinder,
When the lubricating member layer 1 is combined so as to form an inner cylinder, both are firmly bonded and at the same time, a reaction occurs between them to form a strong bonded phase.

Even when the back metal layer is a melt forged material or the like, a solid lubricated composite sliding material can be manufactured by the same principle.

When the physical properties of the lubricating member layer and the back metal layer are extremely different, a gradient material can be obtained by inserting a layer having an intermediate composition between them.

For example, the lubricating member layer is a solid lubricant WS ₂
When the back metal layer is made of a Ti alloy and the back metal layer is made of a Ti alloy and one surface is a sliding surface, a mixture layer of WS ₂ , Cu and Ti is added as the intermediate layer 3 as shown in FIG. Further, the back metal layer 2 side may have a multilayer structure of two layers or more.

As for the temperature at the time of sintering, if the temperature is less than 700 ° C., the sintering hardly progresses, and if it exceeds 1200 ° C., the solid lubricant is decomposed or deteriorated. The following is recommended.

Since the lubricating substance is oxidized in the oxidizing atmosphere, the sintering atmosphere is vacuum or Ar, N.
A non-oxidizing atmosphere such as ₂ is desirable.

[0048]

【Example】

[0049]

Example 1 Tungsten disulfide powder, molybdenum disulfide powder of solid lubricant and Ni, Fe, Cr of binder phase,
Powder and metal powders such as Mo, W, Ta, Co, Sn, Cu and B are mixed by using a ball mill, stainless steel powder for the back metal layer and copper powder are filled in a mold in layers to form powder. A green compact was prepared with a body molding machine at a pressure of ³ to 5 ton / cm ² , and after sintering in vacuum, a bending test and a friction wear test were performed.

In the bending test, a test piece of 10 × 30 mm having different thickness was used, and a load was applied from the direction of the lubricating member layer.

The friction coefficient is SUS-304 for a disc-shaped sample.
With mating material, speed 25m / min, surface pressure 50kg /
It was obtained by contacting the end faces under the condition of cm ² , and the specific wear rate was obtained under the conditions of a surface pressure of 100 kg / cm ² and a friction distance of 500 m.

The composition and manufacturing conditions of the solid lubricating composite material bearing member of the present invention are shown in Table 1. Table 2 shows the bending strength, friction coefficient and specific wear rate of the sintered body. Tables 1 and 2 also show the composition of the comparative example deviating from the present invention, the manufacturing conditions, and the characteristics of the sintered body.

The products of the present invention are sample numbers 1 to 5, and the back metal layer is an example of an iron-based alloy and a copper-based alloy.

In the product of the present invention, a compound containing boron having excellent lubricity is formed between the lubricating member layer and the back metal layer, the bending strength is 20 kg / mm ² or more, and the friction coefficient in the atmosphere and vacuum is 0. It can be seen that a self-lubricating composite material having excellent strength and lubricity is obtained when the ratio is 1 or less.

Comparative examples deviated from the present invention are sample Nos. 6 and 7, where 6 has a small friction coefficient but the backing layer does not exist, so the strength of the sintered body is low, and 7 has less solid lubricant in the lubricating member layer. Therefore, the strength is high, but the lubricity is poor.

[0056]

Example 2 80% by weight of WS ₂ having a particle size of 100 μm, 15% by weight of iron powder having a particle size of 15 μm, 4.5% by weight of nickel powder having a particle size of 5 μm, and 0.5% of boron powder having a particle size of 3 μm. The mixed powder mixed by weight% is press-molded at a pressure of 5 t / cm ² to form a green compact having an inner diameter of 34 mm, an outer diameter of 40 mm, and a length of 59 mm. The inner diameter is 40 mm, the outer diameter is 50 mm, and the length is 60 m.
m SUS304L stainless steel pipe was fitted inside and sintered in vacuum at 1100 ° C. for 30 minutes to prepare a bearing member.

The lubricating member layer and the stainless steel of the back metal layer are firmly adhered to each other, are excellent in lubricity, and are in operation as a bearing member capable of withstanding a high load.

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

[Table 3]

[0061]

The solid lubricating composite material bearing member of the present invention has a low coefficient of friction and a low specific wear rate and excellent mechanical properties, and can be used in high temperature and harsh atmospheres that could not be used until now. This is an epoch-making material.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a bearing member having an inner side as a sliding surface.

FIG. 2 is a perspective view showing a material having an upper surface as a sliding portion and an intermediate layer of 3 between a lubricating member layer of 1 and a back metal of 2.

[Explanation of symbols]

 1 Lubrication member layer 2 Back metal layer 3 Intermediate layer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C10N 10:02 10:08 10:10 10:12 10:16 20:06 Z 8217-4H 40: 02 50:08 70:00

Claims (3)

[Claims] 1. A sliding material comprising a lubricating member layer on a sliding surface in contact with a sliding or rolling member and a back metal layer bonded to the lubricating member layer, wherein the lubricating member layer has a thickness of 0.1 to 10 m.
m of solid lubricant having a particle size of 1 μm or more and 500 μm or less
S ₂ and MoS ₂ alone or in combination of 5% by weight to 95% by weight, and the remaining bonding portion is N
A metal or alloy powder containing one or more of i, Fe, Cr, Mo, W, Ta, Co, Sn and Cu and 0.
B of from 05 to 2.0 by weight
A solid-lubrication composite sliding material characterized by being a sintered phase containing 2. A solid lubricant having a particle size of 1 μm or more and 500 μm or less, WS ₂ or MoS ₂ alone or in combination of 5% by weight or more and 95% by weight or less, and Ni having a particle size of 100 μm or less forming the remaining bonding portion, Fe, Cr, M
o, W, Ta, Co, Sn, Cu, a metal or alloy powder containing one or more of them, a mixed powder of 0.05 to 2.0 weight percent B and a metal forming the back metal layer. Powder or metal powder mixture,
A method for producing a solid-lubricated composite sliding material, comprising filling in a mold in a layered manner, press-molding, and then sintering at a temperature of 700 ° C. or more and 1200 ° C. or less in a non-oxidizing atmosphere. 3. A solid lubricant having a particle size of 1 μm or more and 500 μm or less, WS ₂ or MoS ₂ alone or in combination of 5% by weight or more and 95% by weight or less, and Ni having a particle size of 100 μm or less forming the remaining bonding portion, Fe, Cr, M
A metal or alloy powder containing one or more of O, W, Ta, Co, Sn and Cu, and a mixed powder of 0.05 or more and 2.0 or less weight percent B is pressed into a backing metal. It is brought into close contact with a metal or metal powder press-molded body forming a layer,
A method for producing a solid lubricating composite sliding material, which comprises sintering at a temperature of 0 ° C. or more and 1200 ° C. or less.