JP2000136827A - Manufacture of slide member and slide member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress thermal distortion and abrasion resistance by forming a ceramic film on a surface of a sliding parts while relatively moving torch for flame spraying composite powder of powder ceramic material or ceramics and solid lubricating material. SOLUTION: In the case where a slide member on which a ceramic film is formed on a circumferential surface of a sliding shaft 1 is manufactured, at least two kinds of ceramic powder 12, 13 are put into an arc electric furnace 10, and heated and fused by arc discharge. After they are completely fused, a temperature falls down, and the ceramic powder 12, 13 are coagulated. A coagulation block is broken in a mill 20 to a grain size of 10 to 50 μm by a rotary blade 21. The obtained eutectic ceramic powder is flame sprayed while rotating the sliding shaft 1 by a flame spray gun 30 and while regulating a flame spray temperature to 1,500 to 3,500 deg.C, and a ceramic film whose porosity is 2 to 20% is formed. Fluorine contained resin and the like are impregnated on the ceramic film so as to provide a slide member having little abrasion resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member as a mechanical element, and more particularly to a method of manufacturing a sliding member having a ceramic film and a sliding member.

[0002]

2. Description of the Related Art Generally, sliding members are required to have wear resistance, heat resistance, conformability, and the like. A typical example of such sliding members is a bearing. These bearings include bearing copper made of high-carbon chromium copper, or tin-based alloys known as Babbitt metal, lead-based, copper-based alloys, and bearing alloys made of various sintered ceramics.

[0003] In addition, as the sliding member, copper which has been subjected to carburizing treatment, nitriding treatment, and quenching treatment for improving wear resistance, or a material obtained by spraying another metal on the copper surface is used.

[0004]

When the two members slide, the sliding part wears due to frictional resistance,
This abrasion causes backlash in the material, making smooth sliding impossible, as well as generating heat in the sliding portion and causing material distortion.

[0005] The sliding portions of the sliding members opposed to each other will rather wear if the hardness of both members is extremely high, and if the hardness of both members is too low, the amount of wear will increase again, and eventually the conformability of both members will increase. It is an important factor in reducing wear, and the idea of receiving a soft object against a hard object is important.

Recently, ceramics have been attracting attention as a wear-resistant material, and there are ceramic sliding members which are polished after plasma-spraying ceramic on a long shaft.
In such plasma spraying, ceramics are melt-sprayed at about 3200 to 3300 ° C., so that not only thermal strain remains on the metal substrate and high dimensional accuracy cannot be obtained but also the ceramic film is porous, Not only have insufficient wear resistance due to the presence of unevenness, but also have a problem of high frictional resistance. There is also the problem of being intolerable.

Further, there is not enough consideration on a material having good compatibility with a ceramic film as a sliding member, and a slide having high abrasion resistance in consideration of such compatibility, low frictional resistance and little friction. The appearance of moving members is desired.

In view of the above, the present invention has no thermal strain,
Moreover, it is an object of the present invention to provide a method for manufacturing a sliding member and a sliding member which have low abrasion resistance and no wear on the sliding member.

[0009]

SUMMARY OF THE INVENTION Therefore, a method of manufacturing a sliding member according to the present invention provides a method for manufacturing a sliding member, comprising: a surface of a sliding component and a torch for thermal spraying a composite powder of a ceramic material or a ceramic and a solid lubricant; It moves within the range where no thermal strain remains on the surface of the sliding component, adjusts the spraying temperature to 1500 to 3500 ° C. to form a ceramic film having a porosity of 2 to 20%, and impregnates the ceramic film with an impregnating material. I did it.

Further, the sliding member of the present invention has a porosity of 2 to 2.
A 20% ceramic film was formed on the surface of the sliding component, and this ceramic film was impregnated with an impregnating material.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the sliding member S of the present invention is a first sliding member.
A sliding shaft 1 as a sliding member and a bush 2 as a second sliding member on which the sliding shaft 1 is slidably supported. A ceramic film 3 as a sliding surface is formed, and a flange 4 is formed at an end thereof. Further, the bush 2 is formed of a main body cylindrical portion 5 and a flange 6 formed at one end thereof, and a sliding surface is formed on an inner surface thereof.

The base material of the sliding shaft 1 is generally a metal,
For example, stainless steel is generally exposed to high temperatures during ceramic spraying. Therefore, as a substrate, a material having high heat resistance and small thermal strain and a material having high wear resistance are preferable. Can be

The ceramic to be sprayed is A
l ₂ O ₃ , Cr ₂ O ₃ , TiO ₂ , and composite powder (Al ₂ O ₃
—TiO ₂ , Al ₂ O ₃ —CoO, Al ₂ O ₃ —SiO ₂ , A
l ₂ O ₃ —MgO, Al ₂ O ₃ —ZrO ₃ , ZrO ₂ —Mg
O). Further, a composite powder obtained by electroless nickel plating on the surface of such ceramics and graphite (M ₀ S ₂ ) as a solid lubricant may be used.
The bush 2 is preferably made of a bearing alloy having good compatibility with a hard ceramic film, for example, 7/3 brass, 6
/ 4 brass, Pb-Sn-Sb system, Sn-Sb-Cu system,
Alternatively, Sn-Cu-Pb-based white metal is preferable. In addition, cast iron can also be used. In addition, brass impregnated with molybdenum disulfide (M ₀ S ₂ ) may be used.
In addition, Teflon, brass, boron nitride, graphite, and diamond powder dispersed therein, or a polymer material impregnated with boron nitride, graphite, diamond, and molybdenum disulfide may be used.

[0015] The hardness of brass is about HV60-160, and the hardness of a bearing alloy such as Sn-Sb-Cu is HV.
The hardness of cast iron is about HV150-30.
It is about 0. Generally, the hardness of the ceramic film is HV7
The hardness of the sliding surface of the bush that comes into contact with it is 1/100 of the hardness of the ceramic film in order to improve the conformability.
It is preferably at most 2 and more preferably at most 1/3.

Next, a method for forming a ceramic film on the sliding shaft 1 will be described.

In FIG. 2, an electrode 11 is provided in an electric arc furnace 10, and the above-mentioned ceramic powder 12.13 is supplied into the electric arc furnace 10. The powder supplied into the furnace may be a single powder or a composite of two types of powder, but from the viewpoint of adjusting the hardness of the sliding surface and lowering the melting point, two or more types of ceramic powder are used. It is better to mix. In the electric arc furnace 10, each ceramic powder is heated to about 3000 ° C. by arc discharge. Although both powders are completely melted in the furnace, it is preferred to select the proportions and components such that a eutectic is formed when the temperature drops to a solid. After both powders are completely melted in the electric arc furnace 10, the temperature is lowered to solidify. afterwards,
The solidified block is supplied into the mill 20 and the particle size is 10 to 50 μm, preferably 30 to 40 μm by the rotation of the rotary blade 21.
Mill to μm. The pulverized ceramic powder at this time is preferably a eutectic. If the particle size is too small, the inertia when sprayed by the spray gun is small, and the effect of anchors that bite on the surface to be sprayed will be small.If the particle size is too large, the melting temperature will be high, and the thermal distortion of the surface to be sprayed will be a problem. Becomes

Next, this ceramic powder is sprayed with a spray gun 3
0, the spraying is performed while rotating the sliding shaft 1. Normal ceramic spraying is performed at 3200 to 3300 ° C. In the present invention, ceramic powder is sprayed at a temperature of 2900 ° C to 3000 ° C so as not to cause thermal strain on the sliding shaft 1. Thereby, a more accurate sliding member can be obtained.

The low-temperature thermal spraying method is a low-temperature gas thermal spray using oxygen / acetylene as a heat source, and uses a ceramic powder whose melting point is 2000 ° C. or less. Conventionally, ceramic spraying is generally performed by plasma spraying. In this plasma spraying, it has been considered desirable to increase the spraying temperature, completely melt the ceramic powder, and smooth the sprayed surface. In addition, emphasis has been placed on selecting a material having high hardness and no wear as the material of the sliding member. However, in the present invention, contrary to the above-mentioned conventional idea, a ceramic membrane is provided with many pores, and the pores are impregnated with a soft impregnating material, and a high hardness portion is mixed with an impregnating material having a small frictional resistance. The focus was on creating a surface with low frictional resistance as a whole.

Next, this thermal spraying method will be described in detail with reference to FIGS.

In FIG. 9, the sliding shaft 1 is rotated at a predetermined speed, and a gas torch 30 for oxygen acetylene is used at 2900 to 3000 ° C. (particularly 2900 to 2950 ° C.).
C. is preferable), and the molten ceramic powder is sprayed on the surface of the sliding shaft 1. The rotation speed of the sliding shaft 1 is
The temperature of the peripheral surface of the sliding shaft 1 heated by the gas torch 3 is set to about 40 to 60 ° C., which is a range where no thermal strain remains there. Although it depends on the properties of each material to be sprayed, in general, if the diameter of the sliding shaft 3 is 25 mm to 30 mm, the rotation speed is 300 to 500 rpm, which is approximately 23 m when converted to the surface speed. / Min-47m / min
Rank. The distance between the gas torch 30 and the surface of the sliding shaft 1 is preferably about 12 to 15 cm.

Generally, 99% of the energy of the flame from the torch is a loss, and the torch and the material to be sprayed (sliding member) are relatively moved at a predetermined speed (the torch may be moved).
By doing so, it was confirmed that the surface temperature of the material to be sprayed was suppressed to a range of about 40 to 50 ° C.

Therefore, according to the thermal spraying method, the cloth,
Ceramic spraying can be performed on paper and the like. In this thermal spraying method, since the thermal spraying temperature is 2900 to 3000 ° C., which is lower than that of ordinary plasma spraying, the porosity of the thermal sprayed surface is 2
It becomes about 20% and becomes porous. Generally, the porosity can be adjusted to 10 to 15% by adjusting the melting point of the ceramic powder, the particle size of the ceramic powder, the spraying temperature, the spraying time, the specific gravity of the spraying speed (gas pressure) powder, the temperature of the surface to be sprayed, and the like. preferable. Therefore, since the TiO ₂ powder melts at 1500 to 1700 ° C., the thermal spraying temperature is 15 ° C.
Even at about 00 ° C., it is possible by adjusting other elements, and the upper limit is 3500 ° C. which can be adjusted so as not to cause thermal strain.
Can be set. The thickness of the coating formed on the shaft is preferably about 10 to 300 μm. in this way,
Although the surface is slightly rough when sprayed, Teflon powder is supplied on a shaft in a vacuum furnace 40 to be impregnated in a vacuum. As a result, the Teflon sliding property is given to the ceramic forming film, and a completely oil-less sliding member is obtained. As the impregnating material, a polymer material in which molybdenum disulfide, boron nitride, pitch fluoride, and diamond are dispersed can be used in addition to a fluorine resin such as Teflon. In this embodiment, as shown in FIG.
1 is impregnated, and then the shaft peripheral surface is polished with a grindstone 50 to finish the peripheral surface so that the average roughness Ra is 0.2 μ or less.

In the sliding shaft 1 thus produced, the hardness of the ceramic film formed on the peripheral surface thereof is generally Vickers hardness HV700 or more, and the bush 2 receiving the same has good conformability as described above. It is made of a material having a hardness of 1/3 or less of the hardness of the ceramic film. It is preferable to add a metal such as molybdenum (Mo) to the matrix of the bush 2 to slightly increase lubricity. Such a sliding member hardly wears out (± 3 μm or less), and therefore has no surrounding dirt, no seizure, no thermal expansion of the sliding member itself, can be completely oil-free, and can be lubricated oil. Supply can also be omitted. Such a ceramic sliding member is resistant to changes in load (load, speed) and has little effect on wear even if the load is significantly increased. This property is completely different from that of a conventional oil-less sliding member. can not see.

Further, since there is almost no abrasion, if a ceramic film is formed on a metal substrate in the form of a seal, it can be used instead of a graphite or rubber seal. Such a sliding member is free of dirt because there is no abrasion powder. For example, a bearing of a device used in a clean room such as a semiconductor manufacturing device, a machine of a food manufacturing device or a medical device due to the chemical and wear resistance of ceramics. It can be used as an element or as a mechanical element in high-speed and high-precision equipment such as precision lathes and precision measuring devices. The rail 2 of the linear guide LG as shown in FIG.
It is also possible to treat the sliding shaft 3 on the guide surface 200a of the 00 in the same manner, and to slide the carrier body 201 treated in the same manner as the bush 2 on the rail 200.

Hereinafter, embodiments will be described.

[0027]

[Experimental example] Al ₂ O ₃ and TiO ₂ powder (titania)
Supply into the arc electric furnace at a ratio of 0:40, 3000 ° C
And solidified by cooling, then pulverized with a mill to a particle size of 3.
A eutectic of 0-50 μm was produced. This eutectic powder was sprayed at a low temperature with a diameter of 13, 16, 20 of SUS304.
mm at a speed of 300 to 500 rpm, and a thickness of 0.3 to 0.35 mm over a length of 60 to 100 mm on the shaft.
Was formed, the film was impregnated with fluorinated acrylic in a vacuum furnace, and finished to an average roughness Ra of 0.15 μm with a grindstone.

As the bush, 6/4 brass containing molybdenum silicide in a matrix was used. The hardness of the ceramic film at this time was Rockwell hardness HRC6.
0 to 64, and the hardness of the sliding surface of the bush 2 is HRC.
1.5-6.

As shown in FIG. 3, the moving frame 60 is composed of a base frame 61 and a mounting frame 62 mounted thereon, and the protruding portion 62a of the mounting frame is provided as shown in FIG. The bush 2
5, the shaft 1 is fixedly disposed so as to penetrate the base frame 61 so that the shaft 1 is engaged, and the moving frame 60 is moved by a moving device including a motor (not shown).
Was reciprocated 50 million times up and down. The dimensional change of the film of the shaft 1 (post) at this time is shown in Table 1 and FIG.

[0030]

[Table 1] In this case, the upper part, the central part, and the lower part of the post indicate the part a, the part b, and the part c of the shaft 1 in FIG. 3, respectively.
According to this, the upper part of the shaft is hardly worn, the center part of the shaft is worn by about 1 μm in the range of 0 to 10 million strokes, and the lower part of the shaft is in the range of 0 to several 20 million strokes. It turns out that it wears about 3 micrometers. In addition, no abrasion occurs when the number of strokes exceeds 20 million times.

Table 2 and FIG. 7 show dimensional changes of the sliding surface of the bush 2 at this time.

[0032]

[Table 2] In this case, the upper, middle, and lower portions of the bush indicate the portions a, b, and c in FIG. 4, respectively. According to these tables and figures, the dimensional change in the upper part of the bush is about 1.10 in the range of about 11 million strokes from the start of sliding.
5 μm, and the center of the bush is as small as 0.5 μm in the range up to 11 million times. Further, it can be seen that there is almost no wear after 11 million times.

In consideration of both the sliding surfaces of the sliding shaft 1 and the bush 2, when the number of strokes is more than 20 million times, the two sliding surfaces are completely adapted and the interface state is different from the initial state. It can be seen that the wear of the steel is almost zero. That is, as a result of sliding about 20 million times between the sliding shaft 1 and the bush 2, self-fringing is performed between the sliding surface of the sliding shaft 1 and the sliding surface of the bush 2, and It is considered that an ultrathin mixed film of a ceramic film and a brass film is formed on both surfaces, and that both sliding surfaces are completely adapted to almost no wear. Therefore, if both sliding members are incorporated as mechanical elements into various devices after self-flying, a mechanism free from dimensional errors of the devices can be secured.

Table 3 and FIG. 8 show the temperature changes of each part of the moving frame shown in FIG. 3 at this time.

[Table 3] Here, A, B and C in Table 3 represent the position near the bush 2 of the mounting frame, the position near the sliding shaft on the base frame, and the side position of the base frame shown in FIG. Each is shown. According to this, although the temperature of the motor for reciprocating the moving frame 10 is about 50 ° C., the temperature of the sliding surface of the bush 2 is between 30 and 40 ° C., and the positions A and B of the moving frame 10 are different. , C are higher than the temperature of the sliding surface of the bush 2. This seems to indicate that the temperature effect of the motor is exerted on the moving frame 20, and it is understood that the temperature rise of the sliding surfaces of the sliding shaft 1 and the bush 2 is negligibly small. There is no need to consider the expansion of the sliding member, and the sliding member becomes an ideal sliding member.

Although the above-described sliding member has been shown to be applied to a reciprocating motion, it goes without saying that it can be applied to a bearing for a rotary motion.

[0036]

Since the present invention is constructed as described above, it is possible to provide a sliding member which is free from distortion, resistant to remarkable changes in load, and hardly worn.

[Brief description of the drawings]

FIG. 1 is a front view of a sliding member of the present invention.

FIG. 2 is a process chart showing a method for manufacturing a sliding member of the present invention.

FIG. 3 is a perspective view of a moving frame incorporating the sliding member of the present invention.

FIG. 4 is a perspective view of a bush as a second sliding member of the present invention.

FIG. 5 is a front view of a sliding shaft as a first sliding member of the present invention.

FIG. 6 is a line graph showing a state of wear of a sliding shaft.

FIG. 7 is a line graph showing a worn state of a bush.

FIG. 8 is a line graph showing a temperature change of each part of the moving frame incorporating the sliding member of the present invention.

FIG. 9 is a detailed view of a thermal spraying method according to the present invention.

FIG. 10 is a surface state diagram of a sliding member after thermal spraying.

FIG. 11 is a perspective view of a linear guide to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sliding member 2 ... Bush 3 ... Ceramic film 10 ... Arc electric furnace 20 ... Mill 30 ... Thermal spray gun 40 ... Vacuum furnace 50 ... Whetstone

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J011 DA02 QA04 SC04 SD01 SD04 SD10 SE02 SE04 SE06 SE10 4K031 AA02 AB08 CB01 CB09 CB42 CB43 CB44 CB46 CB49 CB50 CB51 DA01 EA01 EA02 EA10 FA07 FA08

Claims (10)

[Claims] 1. The surface of a sliding part and a torch for spraying a powdered ceramic material or a composite powder of a ceramic and a solid lubricant are relatively moved to the surface of the sliding part within a range where thermal strain does not remain on the surface of the sliding part. A method for manufacturing a sliding member, comprising: forming a ceramic film having a porosity of 2 to 20% by adjusting the temperature to 1500 to 3500 ° C .; and impregnating the ceramic film with an impregnating material. 2. The method according to claim 1, wherein the torch is a gas torch. 3. A method in which at least two or more ceramic materials are melted and solidified by cooling, and then pulverized to prepare a eutectic ceramic powder having a predetermined particle size, and the eutectic ceramic powder is sprayed with a torch. The method for manufacturing a sliding member according to claim 1. 4. The ceramic material is Al ₂ O ₃ —Ti.
_{2. The} method for manufacturing a sliding member according to claim 1, wherein O ₂ is used, and the mixing ratio is 6: 4. 5. The method according to claim 1, wherein the impregnating material is made of at least one of a fluorine resin, molybdenum disulfide, boron nitride, pitch fluoride, and a polymer material in which diamond is dispersed. A method for manufacturing a sliding member. 6. A sliding member, wherein a ceramic film having a porosity of 5 to 20% is formed on the surface of a sliding component, and the ceramic film is impregnated with an impregnating material. 7. The ceramic film is made of Al ₂ O ₂ −
The sliding member according to claim 6, characterized in that the TiO _2. 8. The slide according to claim 6, wherein said impregnating material is made of at least one of Teflon, molybdenum disulfide, boron nitride, pitch fluoride, and a polymer material in which diamond is dispersed. Moving member. 9. A first sliding member having a sliding portion in which an impregnating material is impregnated in a ceramic film having a porosity of 5 to 20% formed by spraying ceramic powder, and engaging with the first sliding member. A sliding portion of the second sliding member, the sliding portion of the second sliding member being formed of a material having a hardness of 1/2 or less than that of the sliding portion of the first sliding member. Moving member. 10. The sliding portion of the first sliding member is made of Al ₂ O _3.
Consists impregnated with the impregnant eutectic powder -TiO _2, sliding member according to claim 9, wherein the sliding portion of the second sliding member, characterized in that it consists of a copper alloy.