JPS6326421A - Rolling slide member for magnetic recorder - Google Patents

Abstract

PURPOSE:To improve processing and sliding characteristics of slide member consisting of ceramic porous material made through a sintering process without blocking the pores existing in a formed body, by specifying its surface roughness as well as by filling open pores with lubricant. CONSTITUTION:A magnetic head 2 is moved toward a magnetic recording disc 1, thereby, in a magnetic recorder making an access of the magnetic head 2 to the magnetic recording disc 1 the magnetic disc 2 is integrally fitted to a carriage (rolling slide member) 3, and this carriage 3 is placed on a bearing (rolling slide member) 4. A rolling slide member suitable for such an apparatus as mentioned above is formed from ceramic porous material equipped with open pores of a three dimentional network by sintering said material without blocking pores included in a formed body. Furthermore, the surface roughness of this slide member is under 0.8S, and lubricant is to be put in the open pores of the slide member.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rolling sliding member that constitutes a magnetic recording device and supports a magnetic head on a movable moat.

(Prior Art) There are various types of magnetic recording devices, and the typical types are as schematically shown in FIGS. 1 and 2. That is, what is shown in these figures is
A magnetic head is moved relative to a rotating magnetic recording disk, thereby allowing a magnetic head to access the magnetic recording disk. The magnetic head in this case is integrally supported by the carriage, and the carriage is placed on a rotatable bearing, so that the magnetic head can freely move relative to the magnetic recording disk. It is possible to move.

In the following description, carriages, bearings, etc. in one or more magnetic recording devices are referred to as rolling sliding members.

In such a magnetic recording device, it is necessary that the rolling sliding members such as the carriage and bearings satisfy the following conditions.

- Since this type of rolling sliding member is frequently moved at high speeds, it must not be easily frayed by sliding.

■Of course, this rolling sliding member must have low rolling sliding resistance.

(2) This rolling sliding member is preferably one that can perform rolling sliding in a dry state, considering the adverse effects on the magnetic recording disk.

(2) This rolling sliding member is preferably made of a non-magnetic material in view of the adverse effects on magnetic recording disks, magnetic heads, etc.

Conventional rolling sliding members of this type have mainly been made of metal. Examples of combinations of carriages and bearings include those made by combining stainless steel and stainless steel, or those formed by sintering stainless steel and alumina into a dense state. However, as long as stainless steel is used as the material, at least the above condition (2) cannot be satisfied.

In addition, in the case of a combination of stainless steel and alumina sintered into an m-dense state, it appears that the condition (■) is satisfied, but since the alumina is hard, the stainless steel side may wear out. This poses a problem in that the resulting wear particles are more likely to have an adverse effect on magnetic recording disks and the like.

Naturally, it may be thought that both the carriage and the bearing could be made of ceramics such as alumina. However, since ceramics have high hardness, mechanical processing after sintering is quite difficult, especially when sintered to a dense state. For this reason, it is conceivable to perform a predetermined process in consideration of firing shrinkage in the state of the formed body and then fire this. However, even when fired with these considerations in mind, the dimensional accuracy of rolling sliding members inevitably deviates, and rolling sliding members for magnetic recording devices that require particularly high dimensional accuracy cannot be manufactured using ceramics. This requires highly sophisticated technology to construct, which is one of the reasons for the high price of the product.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned actual situation, and the problems to be solved are the negative effects on magnetic recording disks etc. caused by conventional rolling sliding members. This is also the difficulty of processing when trying to construct a korogari suri@ member using ceramics.

The purpose of the present invention is to improve the machinability of ceramics, thereby making full use of the various characteristics of this ceramic, making it suitable as parts for magnetic recording devices, and also improving its sliding properties. An object of the present invention is to provide a rolling sliding member made of ceramics.

(Means for Solving the Problems) The means taken by the present invention to solve the above problems are as follows: ``The three-dimensional network structure is created by sintering without clogging the pores existing in the formed body. A rolling sliding member made of a ceramic porous body provided with open pores, the rolling sliding member having a surface roughness of o, ssg.
It's below.

A rolling sliding member for a magnetic recording device made of a ceramic composite, characterized in that the open pores of the rolling sliding member are filled with a lubricant.

This means will be explained in more detail below.

The rolling sliding member according to the present invention is obtained by firing the ceramic sintered body constituting it without clogging the pores present in the formed body, and is three-dimensional. The porous body must have open pores with a network structure.The reason for this is that when the pores become independent when the ceramic powder is bonded, the lubricant described below cannot be filled in the independent pores. This is because it becomes difficult to obtain the desired rolling sliding member, whereas a porous body having open pores with a three-dimensional network structure is extremely suitable for filling with lubricant.

Further, the reason why the ceramic sintered body must be a porous body is to ensure ease of processing in the finishing work when completing a rolling sliding member using this sintered body. This is because it is very difficult to finish the surface of dense ceramics by mechanical grinding, but if it is a porous material, mechanical grinding can be performed relatively easily.

Furthermore, by making the ceramic sintered body a porous body with open pores in a three-dimensional network structure, a rolling sliding member made of a general sintered body (1 & dense body) can be When wear powder is detached from the ceramic sintered body by other sliding parts, the detached wear powder is interposed between the sliding surfaces between the members.
This may significantly deteriorate the sliding properties. However, by configuring the ceramic sintered body constituting the rolling sliding member with a porous body as in the present invention, the rolling sliding member is free from the ceramic sintered body that constitutes it while sliding. Even if the wear particles detach, the wear particles are quickly retained in the pores of the nearby ceramic sintered body, and the detached wear particles hardly cause any deterioration of the sliding properties. It is extremely excellent.

As this ceramic porous body, it is advantageous to use one with as high hardness as possible from the viewpoint of wear resistance; for example, An, O, SiO2, Zr0t, Si
C, TiC, TaC1Ba C, W4 C, Cr5Cx
, Sii N4, BN, TiN, AIN, TiB2
, CrB2, or any one or more of these compounds.

Further, it is preferable that the ceramic porous body has an average grain size of crystals constituting the porous body of 50 gm or less. The reason is that if the average particle size is larger than 5081 m, the surface roughness of the sintered body surface will increase, making it difficult for the sliding surface of the rolling sliding member to be smooth, and furthermore, the dimensional accuracy of the rolling sliding member itself will be poor. Because it becomes something. The average grain size of the crystals constituting the ceramic porous body is preferably 20 gm or less.

The ceramic porous body constituting the rolling sliding member of the present invention preferably has open pores of 5 to 50% by volume.The reason is that when the open porosity is 5% by volume or less, the This is because the amount of impregnated or filled lubricant becomes small, making it difficult to fully demonstrate the lubricating properties.On the other hand, if it is higher than 50% by volume, the wear resistance of the ceramic porous body becomes low, especially when This is because it becomes difficult to use it as a rolling sliding member in machines and equipment that require high precision.

The surface roughness of the ceramic porous body constituting this rolling sliding member must be 0.8S or less.

The reason is that the surface roughness of this ceramic porous body is 0.
If it is 8 or more, the sliding surface of a rolling sliding member formed using this porous body will be difficult to become smooth, and the dimensional accuracy of the sintered body itself will deteriorate. Among these, it is preferable that the surface roughness of this ceramic sintered body is not more than O.Is.

Further, in the present invention, it is necessary to use a composite body in which the open pores of a ceramic porous body are impregnated or filled with a lubricant. The reason for this is that by filling or impregnating the open pores of the ceramic porous body with a lubricant, the sliding characteristics as a rolling sliding member can be significantly improved.

Various substances can be used as such lubricants, for example resins or oils are advantageously used.

The resins include epoxy resins, polyimide resins, trimazine resins, polyparaban resins, polyamideimide resins, silicone resins, epoxy silicone resins, acrylic acid resins, methacrylic acid resins, anilic acid resins, phenol resins, urethane resins, and furan resins. , fluororesin, acetal resin, nylon resin, polyethylene resin, polycarbonate resin, polyethylene terephthalate resin.

Styrene acrylonitrile resin, polypropylene resin,
Resins selected from polyurethane resins and polyphenylene sulfide resins can be used alone or in combination.

Further, the oil may be a fluorinated oil selected from fluoroethylene, fluoroester, fluorotriazine, perfluoropolyether, fluorosilicone, derivatives thereof, or polymers thereof, or methyl silicone, methylphenyl silicone, or derivatives thereof. Alternatively, silicone oil, naphthenic oil, or paraffin oil selected from these polymers can be used.

These oils can be used in any of liquid, grease or wax forms. In addition, these fluorine-based oils and silicone-based oils are
Because they have excellent solvent resistance, chemical stability, and heat resistance, they can provide extremely good lubrication properties over a long period of time. It has the advantage that it has low compatibility and is unlikely to leak out even if it comes into contact with these chemical agents. Of course, a commonly used lubricating oil or the like may be used instead of these oils.

The filling rate of these lubricants is preferably at least 10 parts by volume per 100 open pores described above. The reason for this is that if the amount of lubricant filled is less than 10 parts by volume, it is difficult to improve the lubrication characteristics of the rolling sliding member according to the present invention.

When the lubricant is a resin, the method for filling the open pores of the ceramic porous body with a lubricant includes:
A method of heating and melting the resin and impregnating it, a method of dissolving the resin in a solvent and impregnating it, a method of impregnating the resin in a 7-mer state and then adding it to the polymer, or a method of adding atomized resin to a dispersion medium solution. An applicable method is to disperse the resin, impregnate a porous body with this dispersion, dry it, and then bake the resin at the melting temperature of the resin.

When the lubricant is oil, a method for filling the open pores of the porous ceramic body with the oil is to immerse the porous ceramic body in the lubricant whose viscosity has been reduced by heating.

Common methods such as impregnation under vacuum or pressure can be applied.

Next, a general method for manufacturing a rolling sliding member made of this ceramic composite will be described below.

The rolling sliding member made of a ceramic composite according to the present invention is produced by molding ceramic powder as a starting material into an arbitrary shape, such as a plate or roller shape, and closing the pores present in the formed body. It can be manufactured by sintering the porous ceramic body without causing any oxidation, and then filling the open pores of the porous ceramic body with a lubricant.

The ceramic powder that is the starting material has an average particle size of 5
It is preferably 0 pm or less. The reason for this is that when ceramic powder with an average particle size larger than 50gm is used, the number of bonding points between the particles decreases, which not only makes it difficult to produce a high-strength porous body, but also makes the surface rougher. This is because the accuracy deteriorates, and above all, it is preferably 20 pm or less.

Various methods can be applied to mold the ceramic powder into a formed body of any shape and sinter it without clogging the pores present in the formed body. Alternatively, there is a method of self-bonding by pressure sintering, a method of adding a substance that generates ceramics by reaction to ceramic powder and bonding by reaction sintering, or a method of blending a binder such as glass cement with ceramic powder to create a ceramic under normal pressure. A method of bonding by sintering or pressure sintering can be applied.

Furthermore, a method in which silicon carbide is selected as the ceramic for forming this rolling sliding member will be specifically explained.

That is, in this manufacturing method using silicon carbide as a material, a starting material mainly consisting of silicon carbide powder having an average particle size of 10 μm and containing at least 30% of β-type crystal silicon carbide is used. After forming into the desired product shape,
It is advantageous to heat and sinter the material in a non-oxidizing gas atmosphere to a temperature in the range of 1700 to 2100 DEG C., and fill the open pores thus formed with a lubricant by the method described above.

The reason why the silicon carbide powder used in this method is a fine powder with an average particle size of 10 Bm or less is that the average particle size is 10 g.
The formed body molded from powder with a particle size of less than This is because bonding between silicon carbide particles is extremely likely to occur. Therefore, if silicon carbide powder having such a particle size is used, a high-strength sintered body can be obtained even with a relatively low density. In particular, more suitable results can be obtained when the average particle size of the silicon carbide powder is 5 gm or less.

In this method, the silicon carbide powder containing at least 30% of silicon carbide in the β-type crystal is used as the silicon carbide powder because the β-type crystal is a low-temperature stable crystal that is synthesized at a relatively low temperature. This is because the silicon carbide particles are easily bonded to each other during sintering, and a high-strength sintered body can be produced even with a relatively low density, especially when the silicon carbide powder contains 50% or more of β-type crystals. A more suitable result can be obtained.

In this method, the starting material contains at least one selected from boron, aluminum, iron, chromium, lanthanum, titanium, yttrium, erbium, or compounds thereof. Advantageously, it contains 1 to 5.0% by weight of O. The reason is that the substance has the effect of promoting sintering of silicon carbide, and it is possible to produce a high-strength sintered body because it promotes bonding between silicon carbide particles during sintering. The reason why it is advantageous to keep the content of the substance within the range of 0.01 to 5.0% by weight is that if the content is less than 0.01% by weight, silicon carbide particles will not interact with each other during sintering. This is because the effect of promoting the bonding of silicon carbide is small, and on the other hand, if it is more than 5.0% by weight, the amount of the substance contained in the sintered body increases and the original properties of silicon carbide are lost.

In this method, a carbon source that leaves free carbon during calcination can be added to the starting material.

As such a carbon source, any carbon source that exists in the carbon state at the start of sintering can be used, such as phenolic resin, lignin sulfonate, polyvinyl alcohol, cornstarch, sugar, coal tar pitch, and alginate. Various organic materials such as carbon black, pyrolytic carbon such as acetylene black, etc. can be used in the supplement. When such free carbon exists simultaneously with the above substances, it suppresses crystal growth and is effective in obtaining a porous silicon carbide sintered body having fine pores.

In addition, the content of free carbon is as follows: starting material 1
Advantageously, it is not more than 5 parts by weight relative to 00 parts by weight. The reason is that even if more than 5 parts by weight is added, the effect will not change, but on the contrary, the amount remaining in the sintered body will increase.
This is because the strength of the sintered body deteriorates.

According to the method, the starting material is formed into a green body and then heated and sintered in a non-oxidizing gas atmosphere within the range of 1700 to 2100°C, so that the density is 2.1 to 2100°C.
At 10 g/crnj, it is possible to produce a silicon carbide sintered body with a strength of 30 Kgf/1 g+'' or more.The reason for setting the firing temperature in the range of 1700 to 2100°C is as follows.
If the firing temperature is lower than 1700°C, the bonding between particles is insufficient and it is difficult to obtain a sintered body with high strength. If the firing temperature is higher than ztoo°C, the sintered body tends to become dense and porous carbonization occurs. This is because it is difficult to obtain a silicon sintered body.

The porous silicon carbide sintered body has a density of 2.1 to 3.0 g/
Advantageously, the strength is greater than or equal to 30 Kgf/12. The density is 2.1~3.0 g/crn
The reason why it is advantageous to be within the range of 2.13/crn' is because a sintered body with a density smaller than 2.13/crn' has fewer bonding points between silicon carbide particles.
This is because it is difficult to form a sintered body with a strength of 0 kgf/am2 or more, while 3.0 g/crn'
This is because the larger the sintered body, the smaller the proportion of open pores among the pores subjected to the resultant force. Also, the above strength is 3
The reason why it is advantageous for the strength to be 0 Kgf/12 or more is that if the strength is less than 30 Kgf/ms, it will easily break during use and cannot be used effectively. More suitable results can be obtained when the number of layers is 2 or more. 3. The strength in this method is the average bending strength.

Next, the rolling motion member according to the present invention will be specifically explained using examples.

(Example) Example 1 Average particle size is 0.28 μm, β-type crystal content is 94.6
100 parts by weight of silicon carbide powder, 1 part by weight of boron carbide powder, 2 parts by weight of carbon black powder, 5 parts by weight of polyvinyl alcohol, and 300 parts by weight of water,
After mixing in a ball mill for 5 hours, it was spray dried. In addition,
The silicon carbide powder contained 0.29% by weight of free carbon, 0.17% by weight of oxygen, 0.03% by weight of iron, and 0.03% by weight of aluminum.

An appropriate amount of this dried product was collected, molded, and held in an argon gas atmosphere at 1900°C for 10 minutes to obtain a sintered body.

The obtained sintered body has a density of 2.59 g/c and a strength of 45
The Kgf/■ layer 2 had fine open pores uniformly dispersed three-dimensionally, and the open porosity was about 16% by volume.

Next, this sintered body was impregnated with a two-component type epoxy resin under vacuum, and then cured at a temperature of about 150°C.

The proportion of the epoxy resin in the open pores of this sintered body was approximately 96% by volume.

When this resin-filled sintered body was cut with a diamond wheel, it was much easier to cut than the conventional dense silicon carbide sintered body, and the wear of the diamond wheel was also extremely low. I was.

Example 2 2 parts by weight of polyvinyl alcohol, 1 part by weight of polyethylene glycol, 0.5 parts by weight of stearic acid, and 100 parts by weight of water were mixed with 100 parts by weight of α-type alumina powder with an average particle size of 0.4 gm. Spray dried.

This dryness! j! Collect an appropriate amount of the material and use a metal press mold to
．． Molded at a pressure of 5t/cm'' and has a density of 2.3g/cm.
A product form of c try' (59% by volume) was obtained.

This formed body was inserted into an alumina crucible and fired for 1 hour at 1300°C, which is a temperature range in which 5% by weight or more of a liquid phase is not produced during firing in air under atmospheric pressure.

The obtained sintered body has an average crystal grain size of 2.4 pm, is bonded in a three-dimensional network structure, and has a density of 2.3 g/cmf.
f, flat 1'7 bending strength was 6.7 kgf/am2.

After processing this sintered body into the shape of a rolling sliding member, it was impregnated with suspension wood in which polytetrafluoroethylene fine particles with an average particle size of 0.26 gm were dispersed by dipping in a vacuum for 9 hours, and then A composite was obtained by phosphorescence at a temperature of ~400°C and further surface finishing.

The proportion of the voids in the polytetrafluoroethylene porous material filled in this composite was about 62% by volume.

Example 3 The surfaces of the composites of Examples 1 and 2 were further polished to a surface roughness of o and is, and then stainless steel m (SU
Dry sliding test for S304) at 500 mm/
When the ring-on-ring method was used to slide at a sliding speed of s e c and an end face load of l Ok 1; f / cm '' was applied, the friction coefficient was 0.16 in both
S-0,23, and the friction coefficient is 3.7×10-4-zen/
km (f/Maromaro 2) or less, and it was recognized that it had extremely excellent sliding properties.

Example 4 A sintered body produced in the same manner as the porous sintered body produced in Example 1 was processed into a rolling sliding member having the shape shown in FIGS. 1 and 2, and the surface roughness was Next, the open pores were impregnated with perfluoropolyether in an amount of 60% by volume to produce a rolling sliding member.

This rolling sliding member was incorporated into a magnetic recording device with the mechanism shown in Figs. 1 and 2, and practical tests were conducted for an extremely long period of time, but almost no contamination of the magnetic disk by wear particles was observed. Extremely good sliding properties were exhibited over a long period of time.

(Effects of the Invention) As detailed above, the rolling sliding member according to the present invention, which is used as a component used in a magnetic recording device, can be produced by sintering without clogging the pores present in the formed body. It is characterized by forming a ceramic porous body with open air chambers having a three-dimensional network structure, and filling the open pores of this ceramic porous body with a lubricant. It was possible to create a rolling sliding member that has superior machinability compared to other ceramics and also takes advantage of the other characteristics of ceramics.

That is, according to the present invention, it is a non-magnetic material necessary for a rolling sliding member and has wear resistance.

It is possible to provide a rolling sliding member that not only has excellent oxidation resistance and corrosion resistance, but also has excellent rigidity and strength, can be lightweight, and can reduce movement inertia. Moreover, the rolling sliding member according to the present invention has relatively good thermal conductivity and coefficient of thermal expansion, and can reduce the influence of temperature changes in the usage environment.

In addition, in the rolling sliding member according to the present invention, the open pores of the ceramic porous body are filled with lubricant, so even if the rolling sliding member is used for a long period of time, the resin in the open pores is gradually transferred to the surface. It can be leaked. This is due to the fact that this rolling sliding member is made of a porous ceramic material, so there is no rust at all, so there is no clogging of the open pores, and the lubricant remains stable for a long period of time. This is because it allows for leakage to the surface. Therefore, the rolling sliding member according to the present invention,
The necessary lubrication properties do not change over a long period of time, and the sliding properties can be maintained at their initial values for a long period of time.

Furthermore, since the rolling sliding member according to the present invention has excellent lubrication properties as described above, it is most suitable as a rolling sliding member that can be started and stopped relatively frequently and has layers in contact with each other. There are things you can do.

Note that when the rolling sliding member according to the present invention is made of silicon carbide, the rolling sliding member has excellent oxidation resistance and abrasion resistance, has a low coefficient of thermal expansion, and can be machined. Not only can it be made to have excellent properties, it can also be made to have extremely high hardness, and moreover, it can be used under conditions of a high PV value.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a magnetic recording device employing a rolling sliding member, which is the object of the present invention, and FIG. 2 is a longitudinal sectional view of FIG. 1.

Claims (1)

[Scope of Claims] 1.) A rolling sliding member made of a ceramic porous body that is provided with open pores in a three-dimensional network structure by sintering the pores existing in the formed body without clogging them. Therefore, the surface roughness of this rolling sliding member is 0.8.
A rolling sliding member for a magnetic recording device made of a ceramic composite, characterized in that the rolling sliding member has a diameter of less than S, and the open pores of the rolling sliding member are filled with a lubricant. 2.) As the ceramic porous body, Al_2
O_3, SiO_2, ZrO_2, SiC, TiC, T
aC, B_4C, WC, Cr_3C_2, Si_3N_
4. The rolling sliding member for a magnetic recording device according to claim 1, which mainly contains one or more selected from 4, BN, TiN, AlN, TiB2, CrB_2, or compounds thereof. 3.) The rolling sliding member for a magnetic recording device according to claim 1 or 2, wherein the ceramic porous body has an average grain size of crystals constituting the porous body of 50 μm or less. . 4.) The rolling sliding member for a magnetic recording device according to any one of claims 1 to 3, wherein the ceramic porous body has an open porosity of 5 to 50% by volume. 5.) The magnetic material according to any one of claims 1 to 4, wherein the lubricant is filled in an amount of at least 10 parts by volume per 100 parts by volume of open pores of the ceramic porous body. Rolling sliding member for recording devices.