KR890002162B1 - Sliding members coated ceramic and a method for manufacture thereof - Google Patents

Abstract

The workpiece coated with a ceramic material for wear resistance has a metal base with a surface layer in which C and/or O and/or N are present at a higher concentration than in other parts of the base. A metal base also consists of Fe with at least one element from Ni, Cr, Al, Mn, Mg and V. The ceramic coating is applied by a plasma in a gas atmosphere containing an element forming one of the constitutions of the ceramic coating. The surface layer on the base can be produced by DC plasma in an Arcontaining atmosphere.

Description

Sliding member coated with ceramics and manufacturing method thereof

1 is a cross-sectional view schematically showing a member coated with a ceramic according to the present invention,

2, 3 and 4 are schematic diagrams showing an apparatus for producing a ceramic-coated member according to the plasma CVD method, respectively.

* Explanation of symbols for main parts of the drawings

1 support 2 metal layer

3: treated layer 4: ceramic layer

11,31: reaction chamber 12,32: insulator

13,33: gas reservoir 14,34: electrode

15: Shield 20, 40: support

21,41: support member 22: heat generator

23 power 24,38 high frequency power

25: matched 35: diffusion member

36,37: Aerator

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a sliding member coated with ceramics and a method for manufacturing the same, and more particularly, to a sliding member coated with ceramics and a method for manufacturing the same, which are suitable as a member that slides at high speed.

For example, a member that slides at high speed, such as a shaft of a compressor, a cam shaft of an engine, a laser scanner of a laser printer, or a guide rod of a printer, is easily worn. It will have a big impact on the lifetime and performance of the device. Therefore, a general high speed sliding member should use a material with high wear resistance such as high speed steel or cemented carbide.

However, since these materials have high material and processing costs, in order to reduce production costs, relatively inexpensive materials such as cast iron and free-cutting steel are used and the surface is hardened to give lubricity and high strength such as TiN and TiC. A technique for improving the wear resistance of cutting tools by treating ceramics has also been proposed.

Such surface hardening treatments include heat treatment, and lubricating treatments include tuftride treatments, infiltration treatments, and black dyeing molybdenum dioxide coating treatments. However, these methods increase the weight significantly and are sufficient under severe conditions of high speed rotation. There was no durability. In the heat treatment and tuftride treatments, the treatment temperature is very high (above 500 ° C.), so that the support body, which is the material to be treated, may be deformed during the treatment process. Could not apply.

On the other hand, when TiN and TiC are applied to the high-speed sliding member, since the hardness of the ceramic is high, the sliding member of the sliding counterpart is ground, and there is a problem that such grinding residue adheres to the ceramic coating and is pressed.

Accordingly, an object of the present invention is to provide a member coated with ceramics and a method of manufacturing the same, which have high adhesion to a support, excellent wear resistance, and are not pressed without grinding a sliding counterpart member.

Hereinafter, the present invention will be described in detail.

MEANS TO SOLVE THE PROBLEM As a result of long research in order to achieve the above objective of this invention, the element which belongs to group III of silicon or an periodic table of elements, such as the ceramics which have a boron as a main component, can fully satisfy the objective of this invention mentioned above. I found it.

Such a ceramic material can be coated on the support to be treated by sputtering, plasma CVD, or ion plating, but since the treatment temperature is relatively low at 200 to 300 ° C., the support can be prevented from being deformed during processing. The ceramics may be coated even on a member requiring high precision.

However, such ceramics have a drawback that the adhesion to the support is worse than that of TiN and TiC, and it is virtually impossible to coat the ceramics, especially when the support is cast iron such as a compressor shaft.

Accordingly, the present inventors have made various studies to stably and easily coat the ceramics on a support mainly composed of cast iron, and thus, the present invention is formed by forming a high concentration of carbon, oxygen or nitrogen on the surface of the support. It has been found that the ceramics according to can be coated with high adhesion.

On the other hand, ceramics having high wear resistance and not grinding the movement member of the other side are silicon nitride (SiN), boron nitride (BN), silicon carbide (SiC), boron carbide (BC), silicon oxide (SiO), and silicon carbon nitride (SiCxNy). , Boron carbonitride (BCxNy), or silicon carbonate (SiCxOy). Here, SiN and SiO have a Vickers hardness of 1,800 to 2,000, SiC has a Vickers hardness of 2,000 to 2,500, and BN has a Vickers hardness of 2,500 to 3,000.

As described above, the ceramics have high hardness and excellent abrasion resistance, and in particular, when the sliding member of the counterpart is iron, the counterpart is not ground, and such ceramics are sputtering, ion plating, plasma CVD, thermal CVD, light CVD, etc. It can be prepared according to the method, but considering the adhesiveness to the support and the further low temperature treatment is preferable to use the plasma CVD method.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a cross-sectional view schematically showing a sliding member coated with ceramics according to the present invention, in which a ceramic layer 4 is coated on the surface of the metallic support 1.

The support 1 has, for example, a layer 3 containing iron as its main component and abundantly containing at least one element selected from carbon, oxygen or nitrogen, such as carbon.

As such, when the layer 3 containing abundant carbon, oxygen or nitrogen is formed on the surface of the support 1, and then the ceramic layer 3 is formed, the ceramic layer 4 is strongly coated on the support 1. do.

The support 1 preferably contains iron and contains at least one element selected from nickel, chromium, aluminum, manganese, magnesium or vanadium.

Such an additive component such as nickel is an element that promotes carbonization, oxidation and nitriding in the carbonized layer, oxide layer or nitride layer to be formed on the surface of the support 1 according to the method described below.

The ceramic layer 4 is mainly composed of silicon or an element belonging to group III of the periodic table, such as boron. In the process of forming the ceramic layer, hydrogen or a halogen element may be contained in the ceramic layer, but such a component is 20 atoms. When contained at a concentration of less than or equal to%, it does not adversely affect the wear resistance of the ceramics.

Referring to the method of manufacturing a ceramic-coated member according to an embodiment of the present invention.

First, a block such as cast iron or free-cutting steel is processed into a specific shape such as a shaft of a rotary compressor or a carriage guide of a printer to obtain a support. Subsequently, plasma is generated with a gas containing argon gas to treat the surface of the support, and then ceramics such as SiN are coated on the surface of the support. In the shaft, carriage guide, etc. manufactured in this way, ceramics, such as SiN, are covered by the surface of the support which has iron as a main component. Therefore, even if the sliding member is sliding at a high speed to such a member, not only the wear is suppressed but also does not grind the sliding member.

Next, a method of manufacturing a sliding member coated with ceramics by the plasma CVD method will be described with reference to FIGS. 2 and 3.

The cylindrical reaction chamber 11 is vertically axially supported and is electrically separated by inserting an insulator 12 while being supported on a suitable support. The reaction chamber 11 is a mechanical pressure pump or a flow pump ( (Not shown) to maintain a vacuum degree of about 10 ^-3 Torr. Various raw material gases are introduced into the reaction chamber 11 through the gas inlet 13, and the cylindrical electrode 14 is provided in the reaction chamber 11 so as to have the same axis with respect to its peripheral wall, and the reaction chamber 11. It is set to the same potential as).

The electrode 14 is provided with a plurality of vent holes (not shown), the gas introduced into the reaction chamber 11 through the gas inlet 13 passes through the vent hole of the electrode 14 to the reaction chamber ( It is supplied almost uniformly to the center part of 11).

The cylindrical shield 15 is grounded and laid as if it surrounds the reaction chamber 11, and in the center of the reaction chamber 11, the cylindrical support 20 is perpendicular to its axial direction and the electrode It is installed in the center of shaft of (14). A support member 21 is provided on the mother plate of the reaction chamber 11 with the insulator 12 interposed therebetween, and the support 20 is attached to the support member 21 and enters the reaction chamber 11. The support body 20 has a heat generator 22 made of a resistance heating wire inserted into a central portion thereof, and the heat generator 22 is connected to a power source 23 so that electricity is supplied from the power source 23 to support the support body 20. It is supposed to heat.

Meanwhile, in FIG. 2, the support 20 and the support member 21 are connected to the high frequency power supply 24 through the matching box 25. In FIG. 3, the matching box 25 is connected to the reaction chamber 11. It is connected and supplies high frequency electric power to the reaction chamber 11. That is, as shown in FIGS. 2 and 3, high frequency power is supplied to the support 20 or the reaction chamber 11 so that plasma discharge occurs between the support 20 and the reaction chamber 11.

According to the device thus constructed, first, the surface of the support is subjected to plasma treatment under argon gas conditions, and then the matching chamber 25 and the supporting member 21 are connected as shown in FIG. ^After exhausting to ^-3 Torr, an argon gas of 200 SCCM is introduced into the reaction chamber 11 through the base inlet 13 while continuously evacuating with a pump to adjust the force in the reaction chamber 11 to 1 Torr.

Subsequently, the support 20 is heated to a temperature of 150 to 300 ° C. while supplying power to the heat generator 22 from the power source 23 to generate heat, and then the high frequency power of 300 W of the support 20 is reduced. The plasma is supplied between the electrode 14 and the support 20, and the plasma treatment time is about 30 minutes. At this time, the treatment gas may be not limited to Ar gas, but a mixed gas obtained by mixing Ar gas and H ₂ , He, or N ₂ may be used.

On the other hand, in the present embodiment, the support may be heated in advance, but since the support is heated by the plasma when plasma is generated, it is not necessary to provide a special heating means.

When the support 20 is not heated using the heat generator 22 in this manner, the high frequency power applied to the support 20 or the like may be increased or the processing time may be extended.

In addition, following the plasma treatment, a gas containing the constituent elements of the ceramics to be coated is introduced into the reaction chamber 11 and the ceramics are coated on the surface of the plasma-treated support. In this case, when the ceramics to be coated are mainly composed of Si, a gas containing Si such as SiH ₄ gas or Si ₂ H ₆ gas, and a N-containing gas such as N ₂ gas or NH ₃ gas when the support is nitride In the case of carbides, gases containing C, such as CH ₃ gas or C ₂ H ₆ gas, are mixed, and in the case of a support oxide, gases containing O, such as O ₂ gas or N ₂ O gas, etc. Mix it.

On the other hand, when the ceramics to be coated have B as a main component, it is preferable to use a gas containing B, such as BF ₃ gas or B ₂ H ₆ gas, instead of a gas containing Si. In this way, the raw material gas is introduced into the reaction chamber 11 and at the same time, the connection of the matching box 25 is exchanged from the support member 21 to the reaction chamber 11, and the connection of the shield 15 is also performed in the reaction chamber 11. ) To the support member 21.

Subsequently, high frequency power is supplied from the high frequency power supply 24 to the reaction chamber 11 and the electrode 14 to generate plasma between the electrode 14 and the support 20. In this way, ceramics containing components of the raw material gas are coated on the surface of the support 20.

Next, representative examples of the coating conditions of the ceramics according to the present invention and the thickness of the ceramic layer on which the film is formed will be described.

(a) for SiN

SiH ₄ gas flow rate: 50SCCM

Flow rate of N ₂ gas: 800SCCM

Reaction pressure: 1.0 Torr

High Frequency Power: 300W

Film formation time: 1 hour

Layer thickness: about 4μm

(b) for SiC

SiH ₄ gas flow rate: 50SCCM

CH ₃ gas flow rate: 300SCCM

Reaction pressure: 1.0 Torr

High Frequency Power: 30W

Film formation time: 1 hour

Layer thickness: about 4μm

(c) for BN

B ₂ H ₆ gas flow rate: 50SCCM

Flow rate of N ₂ gas: 800SCCM

Reaction pressure: 1.0 Torr

High Frequency Power: 300W

Film formation time: 1 hour

Layer thickness: about 4μm

(d) for SiO

SiH ₄ gas flow rate: 50SCCM

O ₂ gas flow rate: 800SCCM

Reaction pressure: 1.0 Torr

High Frequency Power: 300W

Film formation time: 1 hour

Layer thickness: about 4μm

The ceramic-coated sliding member manufactured in this way is coated with high strength ceramics, and has high wear resistance.

Under the above conditions, the shaft for the rotary compressor was manufactured and rotated for 30 minutes at a rotational speed of 10,000 RPM about the biaxial axis, and then stopped for 10 minutes, and then rotated for 30 minutes. .

In the shafts coated with the ceramics shown in the above (a) to (d), none of the pressed parts occurred due to abrasion, and there was no place where the layers were peeled off, and it was proved that the durability was very high.

Further, in the above embodiment, the surface treatment of the support and the coating of the ceramics are carried out according to the plasma CVD method, but other methods such as sputtering, ion plating, thermal CVD, or CVD described above may be used without limitation.

On the other hand, the power for plasma generation may also be used as the direct current, not limited to the high frequency power as in the above embodiment, but in this case there is no need for matching.

As such, the ceramic layer such as SiN, SiC, SiO, or BN in which the film is formed is usually amorphous, but there are polycrystalline portions or only partially crystallized portions or microcrystalline portions. However, all of them have good abrasion resistance and can obtain excellent effects of the same shape.

Next, a method of manufacturing a sliding member coated with ceramics according to the present embodiment according to the present embodiment of FIG. 4 by plasma CVD will be described as an example. The cylindrical reaction chamber 31 is electrically separated through the insulator 32 while being supported on an appropriate support with its axial direction perpendicular thereto. The reaction chamber 31 is exhausted by a mechanical pressurized pump or a flow pump (not shown) to maintain a vacuum degree of about 10 ^-3 Torr, and various raw material gases are introduced through the gas inlet 33. .

The cylindrical electrode 34 is provided in the reaction chamber 31 so as to have the same axis with respect to the peripheral wall of the reaction chamber 31, and a cylindrical diffusion member between the electrode 34 and the peripheral wall of the reaction chamber 31. 35 is formed coaxially with the electrode 34.

The electrode 34 and the diffusion member 35 are each provided with a plurality of vent holes 36 and 37. The gas introduced into the reaction chamber 31 through the gas inlet 33 is the cylinder of the diffusion member 35. The pores 37 and the vent holes 36 of the electrode 34 pass through the pores 37 and are supplied to the center of the reaction chamber 31. In this way, the gas is uniformly diffused into the center of the reaction chamber 31.

The electrode 34 and the diffusion member 35 have the same potential as the reaction chamber 31, and the electrode 34 and the like are connected to the high frequency power source 38 to supply high frequency power to the electrode 34. As shown in FIG.

The support 40 is attached to the center of the reaction chamber 31 at the center of the axis 34 of the electrode 34 with its axial direction perpendicular to the center of the reaction chamber 31. On the mother plate of the reaction chamber 31, the support member is interposed between the insulators 32. 41 is disposed, and the support member 41 is grounded. The support 40 is attached to the support member 41 and enters the reaction chamber 31. Since the support 40 is also grounded like the support member 41, the support 40 is connected to the electrode 34 from the high frequency power supply 38. When the high frequency power is supplied, a plasma discharge occurs between the electrode 34 and the support 40. According to the device configured as described above, the surface of the support is first carbonized to form a portion containing a high concentration of carbon in the surface layer portion. That is, the reaction chamber 31 is evacuated to about 10 ⁻³ Torr, and the gas containing carbon, such as CF ₄ gas or CH ₄ gas, is passed through the gas inlet 33 while continuing to evacuate the pump. The reaction chamber 31 is controlled to have a pressure of 1 Torr, for example, and the plasma is generated by supplying high frequency power between the electrode 34 and the support 40 to carbonize the surface of the support 40. .

At this time, if a plasma is generated by supplying only a gas containing carbon, a film formed by polymerization of carbon by plasma may adhere to the surface of the support. When the film is weak, the ceramic layer formed in the next step is easily formed. It is not good to peel off. Therefore, it is better to introduce a gas such as Ar gas, He gas, or N ₂ gas in addition to the gas containing carbon in the reaction chamber to generate plasma with these gas mixtures. This is difficult to produce and the reaction between carbon and iron proceeds easily. As such a mixed gas, an Ar gas is most preferable in that it is particularly inert and has large ionization energy. An example of general carbonization is as follows.

CH ₄ gas flow rate: 50SCCM

Ar gas flow rate: 300SCCM

Reaction pressure (vacuum degree): 1.0 Torr

High Frequency Power: 500W

Treatment time: 30 minutes

In carrying out the carbonization treatment as described above, the support may be heated in advance, but if a plasma is generated, the support is heated by this plasma, and thus it is not necessary to provide a separate heating device.

As the carbon source, not only the above-mentioned gases but also solids may be used. In this case, carbon may be emitted from a carbon-containing solid by tapping carbon with an Ar plasma.

Following the carbonization treatment, a gas containing a constituent element of the ceramic to be coated is introduced into the reaction chamber 31, and the ceramic is coated on the surface of the carbonized support. In the case where the ceramics to be coated are mainly composed of Si, such as SiH ₄ gas or Si ₂ H ₅ gas, when the main component is Si, the support is nitrided in a Si-containing gas such as SiH ₄ gas or Si ₂ H ₅ gas. In case of N, gas containing N such as N ₂ gas or NH ₃ gas is mixed, and in case of carbide, gas containing C, such as CH ₄ gas or C ₂ H ₆ gas, is mixed. Gases containing O, such as O ₂ gas or N ₂ O gas, are mixed.

On the other hand, when the ceramic gas to be coated contains B as a main component, it is preferable to mix a gas containing B, such as BF ₃ gas or B ₂ H ₆ gas, instead of the gas containing Si. In order to form a SiCxNy film, CH ₄ gas may be added to a mixed gas of SiH ₄ gas and O ₂ gas or N ₂ O gas.

The following is a description of a typical example of the film forming zone and the film thickness of ceramics in which a film is formed by coating ceramics by such a device.

(a) for SiN

SiH ₄ gas flow rate: 100SCCM

Flow rate of N ₂ gas: 300SCCM

Reaction pressure: 1.0 Torr

High Frequency Power: 500W

Film formation time: 30 minutes

Layer thickness: about 3μm

(b) for SiC

SiH ₄ gas flow rate: 100SCCM

CH ₄ gas flow rate: 300SCCM

Reaction pressure: 1.0 Torr

High Frequency Pressure: 500W

Film formation time: 30 minutes

Layer thickness: about 3μm

(c) for BN

Flow rate of BF ₃ gas: 100SCCM

Flow rate of N ₂ gas: 300SCCM

Reaction pressure: 1.0 Torr

High Frequency Power: 500W

Film formation time: 30 minutes

Layer thickness: about 3μm

(d) for SiO

SiH ₄ gas flow rate: 100SCCM

O ₂ gas flow rate: 300SCCM

Reaction pressure: 1.0 thor

High frequency power: 500W

Film formation time: 30 minutes

Layer thickness: about 3μm

The ceramic-coated sliding member manufactured as described above is characterized in that the ceramics are coated with high strength and have high wear resistance.

The rotary compressor shaft was manufactured under the film forming conditions as described above, and the shaft was slid continuously for 30 minutes at a rotational speed of 10,000 RPM, and stopped for 10 minutes, and then slid for 30 minutes. Durability test was performed.

None of the shafts coated with the ceramics shown in the above (a) to (d) were formed due to abrasion, and there was no place where the layers were peeled off, which proved to be very durable.

Further, in the above embodiment, carbonization of the surface of the base material and coating of ceramics are performed by plasma CVD, but not limited thereto, and other methods such as sputtering or ion plating may be used as described above.

As described above, in the sliding member according to the present invention, the ceramic layer is adhered to the support mainly composed of iron with high adhesiveness, and a member having excellent abrasion resistance can be obtained. It can also be prevented from sticking together.

Claims (14)

A sliding member coated with ceramics, comprising: a metallic support (1) having a treatment layer (3) rich in at least one element selected from carbon, oxygen, or nitrogen on the surface thereof, and a surface of the support (1) A sliding member coated with ceramics, characterized in that the ceramic layer (4) coated on. The sliding member according to claim 1, wherein the support (1) contains iron as a main component and contains at least one element selected from nickel, chromium, aluminum, manganese, magnesium or vanadium. 2. A sliding member according to claim 1, wherein the ceramic layer (4) is composed mainly of silicon. The sliding member according to claim 1, wherein the ceramic layer (4) is composed mainly of an element belonging to group III of the periodic table. The sliding member according to claim 3 or 4, wherein the ceramic layer (4) contains at least one element selected from hydrogen or a halogen element. The sliding member according to claim 1, wherein the treatment layer (3) is formed by a plasma of argon-containing gas. 7. A sliding member according to claim 6, wherein the treatment layer (3) is formed by a plasma of a gas containing at least one element selected from carbon, oxygen and nitrogen. The sliding member according to claim 1, wherein the ceramic layer (4) is formed by plasma formed under reduced pressure. The sliding member according to claim 8, wherein the plasma forming the ceramic layer (4) is formed by supplying high frequency power or direct power to the support (1). 2. The sliding member according to claim 1, wherein the ceramic layer (4) is silicon nitride, boron nitride, silicon carbide, boron carbide, silicon oxide, silicon carbide, boron carbonitride, silicon carbonate or boron carbonate. In manufacturing the sliding member coated with ceramics, plasma is generated in the gas atmosphere containing argon on the surface of the metallic support (1) containing at least one element selected from carbon, oxygen or nitrogen, and always on the surface of the support (1). Manufacture of a sliding member coated with ceramics, comprising the step of forming a treatment layer 3 containing a high concentration of an element, and a step of forming a ceramic layer 4 on the surface of the support 1. Way. 12. The method according to claim 11, wherein the metallic support (1) is composed mainly of iron. 12. The method according to claim 11, wherein the ceramic layer (4) is composed mainly of an element selected from silicon or elements belonging to group III of the periodic table. The method according to claim 13, wherein the step of forming the ceramic layer (4) comprises the step of forming a plasma under gaseous conditions containing its elemental elements.

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