JPH04285693A - Sliding member - Google Patents

Abstract

PURPOSE:To provide a sliding member excellent in selflubricating ability and abrasion resistance and readily producible. CONSTITUTION:A sliding member composed of a metal matrix composite plating layer produced by dispersing rigid fine particles covered with a water-insoluble organic polymer substance and codepositing them.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member having lubricity and wear resistance under dry friction conditions and oil lubrication conditions.

0002

BACKGROUND OF THE INVENTION Various combinations of metal matrices and fine particles have been studied for dispersion composite plating in order to provide functions such as self-lubricating properties and wear resistance.

[0003] Surface technology Vol. 30, No. 11, P.
442 (1985) introduces dispersion composite plating in which either hard fine particles or self-lubricating fine particles are eutectoid.Those with hard fine particles dispersed have excellent wear resistance and are suitable for wear-resistant materials or oil lubrication conditions. Although it is used as a sliding member under dry friction conditions, it is difficult to use it under dry friction conditions, whereas those with self-lubricating fine particles dispersed have excellent lubricity but have poor wear resistance. It is known for its scarcity properties.

On the other hand, in Japanese Unexamined Patent Publication No. 01-21096, hard fine particles and self-lubricating fine particles are simultaneously
A sliding member formed of a composite plating layer that is uniformly dispersed and eutectoid has been proposed, and a sliding member that is wear resistant and has excellent self-lubricating properties has been realized.

[0005]

[Problems to be Solved by the Invention] Among the conventional dispersion composite platings described above, those in which hard fine particles and self-lubricating fine particles are uniformly dispersed at the same time have both excellent self-lubricating properties and wear resistance. It is an innovative sliding member that can fully meet the requirements of various mechanical sliding parts, including the need for no lubrication, but it requires a plating process to uniformly disperse two types of fine particles with different properties at the same time. Since it is not always easy to control the sliding member, there has been a demand for a sliding member that has both excellent self-lubricating properties and wear resistance, and is easy to manufacture.

[0006] The present invention seeks to provide a sliding member that can meet the above requirements.

[0007]

[Means for Solving the Problems] The present invention provides a sliding member formed of a metal matrix composite plating layer in which hard fine particles coated with a water-insoluble organic polymer substance are dispersed and eutectoid. be.

The organic polymeric substance constituting the sliding member of the present invention must satisfy the condition of being insoluble in water in order to avoid dissolution in the plating bath during the plating process. polymers, fluorinated ethylene resins (trifluorinated ethylene resins, tetrafluorinated ethylene resins, etc.), polyethylene, polypropylene, polystyrene, etc. are used. The coating state of the hard fine particles with these polymeric substances may be microcapsules in which the hard fine particles are physically coated with an organic polymeric substance, or microcapsules in which the hard fine particles are physically coated with an organic polymeric substance, or chemically coated hard fine particles with organic polymer chains. It may be a bond (covalent bond).

On the other hand, as the material of the hard particles constituting the sliding member of the present invention, in addition to alumina, oxide-based, nitride-based or carbide-based ceramics, etc. are used.

[0010] Copper, cobalt, nickel, etc. are used as the metal matrix constituting the sliding member of the present invention.

[0011]

[Function] The fine particles dispersed in the matrix metal are hard fine particles coated with an organic polymeric substance.The organic polymeric substance has self-lubricating properties, which increases lubricity, and the hard fine particles prevent wear. The sliding member of the present invention exhibits excellent friction and wear characteristics.

[0012] In addition, the conventional sliding member in which hard fine particles and self-lubricating fine particles are uniformly dispersed at the same time has undergone a highly difficult plating process, that is, a process that controls the dispersion of two types of fine particles with different properties. In contrast, the sliding member of the present invention can be manufactured extremely easily since the matrix metal contains only one type of fine particles.

[0013]

[Example] From the viewpoint of dispersibility, the particle size of hard fine particles is 0.5~
2.0 μm, and the coating amount of the organic polymer substance is set to 0.03 to 0.3 in weight ratio to the hard fine particles, and a metal matrix composite plating layer is formed in which hard fine particles coated with an organic polymer substance are dispersed. As a result of the test, two hard particles coated with an organic polymer substance were added to the composite plating layer.
~40vol. It was confirmed that those dispersed within this range had both excellent self-lubricity and wear resistance. next,
A typical example is shown below.

(Example 1) In a reaction vessel equipped with a rotary stirring blade, 100 g of alumina fine particles with an average particle diameter of 2.0 μm, 500 ml of water, and 100 g of 2,2,3,3-tetrafluoropropyl methacrylate were mixed. After keeping at ℃,
1.5 g of potassium persulfate (polymerization initiator) in 100 ml of water
and added to the above mixture, and the rotation speed was 700 rpm.
Polymerization was started while stirring. After 3 hours, the contents of the reactor were cooled with ice, and unreacted 2,2,3,
3-tetrafluoropropyl methacrylate is extracted to stop the polymerization, and centrifugation is performed to obtain alumina fine particles coated with a polymer of 2,2,3,3-tetrafluoropropyl methacrylate (hereinafter abbreviated as coated fine particles A). The weight ratio to the alumina fine particles was 0.28).

Copper sulfate bath (copper sulfate CuSO4 ・5H2
O 200g/l, sulfuric acid H2 SO4 60g/l)
In a plating bath in which coated fine particles A (10 to 200 g/l) were dispersed, a copper matrix composite plating layer with coated fine particles A dispersed therein was deposited to a thickness of 50 to 100 μm on a cylindrical sliding specimen made of carbon copper (S45C). Electrodeposited. The temperature of the plating bath was 25°C, the pH was 0.5, and the current density was 3.5A/d.
m2.

Using a two-cylindrical end face testing machine with the cylindrical test piece coated with dispersion composite plating as described above as a fixed piece and the bearing cable whose surface was induction hardened as a rotating piece, a sliding speed of 0.2 m/ sec, surface pressure 4.9Kgf/cm2
, a dry friction test was conducted in the air at room temperature.

Furthermore, a composite sintered material in which graphite is dispersed in copper, which is a typical metal-based self-lubricating material, was used as a comparative material, and the same dry friction comparison test as above was conducted using the comparative material as a fixed piece.

The above results are shown in Table 1 together with the content of coated fine particles A in the dispersed composite plating layer.

[Table 1]

As is clear from Table 1, the friction coefficient of the sliding member of the present invention comprising a copper matrix composite plating layer in which coated fine particles A are dispersed is as follows. The size is the same as or smaller than the sintered material, has excellent lubricity, and has better wear resistance than the composite sintered material described above.

(Example 2) 100 g of silicon carbide fine particles with an average particle size of 0.5 μm and 500 ml of vinyltrimethoxysilane were mixed in a reactor equipped with a rotary stirring blade, and the mixture was heated at 110° C. while stirring at a rotation speed of 700 rpm. After reacting for 3 hours, silicon carbide fine particles were isolated from the reactor contents by centrifugation. Next, 100 g of this vinyltrimethoxysilane-treated silicon carbide and 50 g of styrene were added.
0 ml and 0.5 g of 2,2'-azobisisobutyronitrile (polymerization initiator) were mixed in a reactor equipped with a rotary stirring blade, and stirred at 700 rpm for 24 hours at 70°C. Polymerization was performed. After polymerization, the contents of the reactor are diluted with toluene, the toluene phase is removed by centrifugation, and then poured into methanol, followed by further centrifugation.
Silicon carbide fine particles with polystyrene covalently bonded to the surface (
Abbreviated as coated fine particles B, the coating amount was 0.03 as a weight ratio to the silicon carbide fine particles.

Copper sulfate bath (copper sulfate CuSO4 ・5H2
O 200g/l, sulfuric acid H2 SO4 60g/l)
In a plating bath in which coated fine particles B (10 to 200 g/l) were dispersed, a copper matrix composite plating layer with coated fine particles B dispersed therein was deposited on a cylindrical sliding test piece made of carbon copper (S45C) to a thickness of 50 to 100 μm. Electrodeposited. The temperature of the plating bath was 25°C, the pH was 0.5, and the current density was 3.5A/d.
m2. Using a two-cylindrical end face testing machine with the cylindrical test piece coated with dispersion composite plating as described above as a fixed piece and the bearing rope whose surface was induction hardened as a rotating piece, the surface was tested at a sliding speed of 0.2 m/sec. Pressure 4.9Kgf/cm
2. A dry friction test was conducted in the air at room temperature.

Furthermore, the same comparative test as in Example 1 was conducted using the same sintered material as in Example 1, in which graphite was dispersed in copper, as a comparative material.

The above results are shown in Table 2 together with the content of coated fine particles B in the dispersed composite plating layer.

[Table 2]

As is clear from Table 2, the coefficient of friction of the sliding member of the present invention comprising a copper matrix composite plating layer in which coated fine particles B are dispersed is as follows. It has the same level of lubricity as binder, and has excellent lubricity.
Furthermore, the wear resistance was superior to that of the above-mentioned composite sintered material.

As is clear from Tables 1 and 2, the amount of organic polymer material coated is 0.0 in terms of weight ratio to the hard fine particles.
3 to 0.3 and coated with an organic polymer substance in 2 vol. % or more provides both excellent self-lubricity and wear resistance, but even if it is contained in a large amount, the effect is not significant, and 40 vol. % or less is a practical range.

[0026]

[Effects of the Invention] The sliding member of the present invention has a composite plating layer in which hard fine particles coated with an organic polymer are dispersed, so that it has excellent both lubricity and wear resistance. Also,
The sliding member of the present invention having this composite plating layer has better lubricity and wear resistance than a composite sintered material of copper and graphite, which is a typical metal-based self-lubricating material, and has excellent sliding properties under dry friction conditions. Can be applied as a moving member. For example, if the sliding member of the present invention is applied to the bearings of a printing press that is currently lubricated with grease, and the bearings of a printing press are lubricated, the paper can be prevented from becoming stained by grease, and maintenance is free.
It has advantages such as low cost.

Claims (1)

[Claims] 1. A sliding member comprising a metal matrix composite plating layer in which hard fine particles coated with a water-insoluble organic polymer substance are dispersed and co-deposited.