JP3355060B2 - Sliding member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material containing a solid lubricant used as a sliding member.

[0002]

2. Description of the Related Art Tungsten disulfide, molybdenum disulfide and graphite are added to various oils and greases as typical solid lubricants, or are used as composite materials with metals, ceramics and plastics, or as dry coatings. .

[0003] Tungsten disulfide (WS ₂ ) is a flaky powder having a hexagonal crystal structure. Composite material of WS ₂ and the metal is a mixture of powder and metal powder WS _2, are produced by hot pressing. WS ₂ is likely to react with the metal at the time of sintering, in particular sintering temperature is high (1000 ° C. or higher), since varies the lubrication-free compound, as a metal composite material produced so far, WS ₂ It is limited to those containing Cu-Sn, Cu-W, Ta, and Ag as main components, which are difficult to react with. Composite materials containing these as main components had low strength, high friction coefficient and large specific wear, and were liable to be oxidized in the atmosphere.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a composite material containing a solid lubricant which has a low coefficient of friction, a small specific wear and can be used in any atmosphere. It is intended to be provided.

[0005]

According to the present invention, there is provided:
Results of investigation of reactivity with WS2 and metals and alloys of the solid lubricant, the sintered body of the WS ₂ and tungsten is excellent in lubricating properties, and enhance the sintering property of tungsten, in order to increase the strength The inventors have found that the addition of small amounts of boron, cobalt, nickel and copper is effective and have completed the invention.

[0006] The present invention relates to tungsten disulfide (WS ₂ ).
30 wt% or more 80 wt% or less and 0.1 wt% or more
0.5 wt% or less of boron (B), 0.50 wt% or more
1.0 % by weight or less of cobalt (Co), 1.0% by weight or less
3.0 % by weight or less of nickel (Ni), 1.0% by weight
Than the 2.0 wt% or less of copper (Cu), 17 wt% or more 6
It is a sliding member with excellent lubricity consisting of tungsten (W) of 4% by weight or less and unavoidable impurity elements.
Sign.

If the WS ₂ content is less than 15% by weight, the material has no lubricating properties. If the WS ₂ content exceeds 85% by weight, the material has low strength and cannot be used . 30 % by weight or more, 80 % by weight
The following is desirable.

[0008] WS ₂ is a powder having an average particle diameter of 1 [mu] m, when it is sintered metal or alloy, for changing the lubrication-free compound reacts during sintering, granulated using a press forming or binder From 10 μm to 20 depending on the grain
It is desirable to add in a lump of 00 μm. If the bulk powder exceeds 2000 μm, mixing with the metal becomes uneven,
Materials with stable properties cannot be obtained.

The most suitable metal or alloy other than WS ₂ is tungsten (W). W Because hardly most reactive with WS _2, the residual amount of WS ₂ in W sintered body is large. However, since W has a high melting point of 3200 ° C., it cannot be sintered at a temperature of 1000 to 1400 ° C. which is usually used for sintering metals. In addition, WS ₂ decomposes at a temperature of 1200 ° C. (in vacuum) or higher. Therefore, at a temperature of 1200 ° C. or less, W
The sintering aid required for sintering, and it is necessary that hardly reacts with WS _2. As an additive for that purpose, a combination of boron (B), cobalt (Co), nickel (Ni), and copper (Cu) is optimal.

B reacts with Co, Ni, and Cu to produce a low melting point compound (980-1150 ° C.), and becomes a liquid phase during sintering to promote sintering of W. B amount is not generated compound having a low melting point is less than 0.05 wt%, degrades WS ₂ in 1.0 wt.% By reacting B is the WS _2. It is desirable that the content be 0.1 % by weight or more and 0.5 % by weight or less.

Co is an element that reacts with B to generate a compound having a low melting point, and that Co itself promotes sintering of W. No effect is less than 0.3 wt%, the 2 weight percent to produce a bad compound lubricity react with WS _2. 0.
5% by weight or more and 1.0 % by weight or less are desirable.

Ni reacts with B to form a low melting point compound and promotes sintering of W itself. No effect is less than 1.0 wt%, 7 weight percent to produce a bad compound lubricity react with WS _2. 1.0% by weight or less
Above, 3.0 % by weight or less is desirable.

Cu reacts with B to form a compound having a low melting point. Although Cu and W have no solubility at all, they have extremely good wettability, so that Cu fills the gaps between W particles and strengthens the W sintered body. No effect is less than 1.0 wt%, 7 weight percent to produce a bad compound lubricity react with WS _2. Desirably, the content is 1.0% by weight or more and 2.0 % by weight or less.

[0014] Composite materials of WS ₂ 30 wt% or more, 80
3 wt% or less, 0.1 wt% or more, 0.5 wt% or less of boron (B), 0.50 wt% or more, 1.0 wt% or less of cobalt (Co), 1.0 wt% or more, 3 0.0 wt% or less nickel (Ni), 1.0 wt% or more, 2.0 wt% or less copper (Cu) , 17.0 wt% or more and 64 wt% or less
Mix the lower tungsten (W) powder, 1 to 10 ton
After molding at a molding pressure of / cm ² , 1000-1300 ° C
At a temperature in a vacuum or an inert atmosphere, and by a production method such as a hot press method or a HIP method.

[0015]

EXAMPLE 1 Tungsten disulfide powder and B, Co, Ni, Cu, W powders were mixed using a ball mill, and then mixed with a press molding machine.
Ton / cm ² to produce a green compact,
The sintered body was manufactured by sintering at ℃. A compression test and a friction wear test were performed on the sintered body.

For the compression test, a test piece having a diameter of 10 mm and a height of 10 mm was used. The friction and wear test was performed using a two-wire tribometer and a coefficient of friction of 10 mm square with SUS-304 as the mating material at a speed of 25 m / min and a load of 20 kg. The specific wear rate was 20 kg. , And a friction distance of 500 m. Table 1 shows the composition of the test materials, and Table 2 shows the test results.

The composite material of the present invention is a material having a higher lubricating property as the content of tungsten disulfide is higher, but having a tendency to decrease in strength. The strength of the composite material is practical if the compressive strength is 5 kg / mm ² or more, and the friction coefficient is 0.
Those having a specific wear amount of less than 5 × 10 ⁻⁷ mm ³ / kg · mm are excellent in lubricity.

[0018]

[Table 1]

[0019]

[Table 2]

The materials Nos. 1, 2, and 3 of the present invention are those in which the amount of tungsten disulfide is within the range of claims, and which has a good balance between strength and lubricity and has a small specific wear. On the other hand, in Comparative Example 4, since the amount of tungsten disulfide was small, the strength was high but the lubricity was poor. Comparative Example 5 had good lubricity but low strength because of too much tungsten disulfide,
Does not stand use.

In Comparative Example 6, the elements that promote sintering of tungsten, such as boron, cobalt, nickel and copper, are insufficient, so that tungsten is not sintered and has low strength. Comparative Example 7,
Nos. 8 and 9 are examples of a large amount of cobalt, nickel and copper, respectively, and have high strength, but react with tungsten disulfide to form a compound having poor lubricity, thereby increasing the coefficient of friction and increasing the specific wear. I do.

[0022]

The composite material of the present invention is a revolutionary lubricating material which has high strength, low coefficient of friction and low specific wear, and can be used in any atmosphere.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI C10M 103: 06) C10M 125: 04 (C10M 169/04 125: 26 103: 06 C10N 10:02 125: 04 10:06 125: 26) 10 : 12 C10N 10:02 10:16 10:06 30:06 10:12 40:02 10:16 50:08 30:06 40:02 50:08 (56) References JP-A-5-320681 (JP, A) JP-A-4-320494 (JP, A) JP-A-4-320496 (JP, A) JP-A-4-320497 (JP, A) JP-A-53-122059 (JP, A) -27130 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10M 103/00 C10M 103/04-103/06 C10M 125/04 C10M 125/22 C10M 125/26 C10M 169 / 04 C10N 10:02 C10N 10:06 C10N 10:12 C10N 10:16 C10N 30:06 C10N 40:02 C10N 50:08

Claims (1)

(57) [Claims] 1. A tungsten disulfide and (WS ₂₎ 30 wt% or more 80 wt% or less, 0.1 wt% or more than 0.5% by weight of boron (B), 0.50 wt% or more 1.0 wt% or less of cobalt (Co), 1.0 wt% or more than 3.0 wt% of nickel (Ni), 1.0 wt% or more 2.0
Copper (Cu) of not more than 17% by weight and not more than 64% by weight
A sliding member excellent in lubricity consisting of tungsten (W) below and unavoidable impurity elements.