JP2007100839A - Sliding body, sliding method, and mechanical apparatus having the sliding body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding body having sliding members to slide via liquid, one of the sliding members having a diamond-like carbon (DLC in the following) film formed on the sliding surface thereof, where the sliding body hardly causes the wear of the sliding members even if the other sliding member (a mating member for the member having the DLC film) is made of a material to easily react on DLC, and further to provide a mechanical apparatus having the same sliding body, and a sliding method. <P>SOLUTION: The sliding body has ceramic powder having a mean grain size of 0.5 to 20 μm in the liquid at the rate of 5 to 200 μg per 1 cm<SP>3</SP>of the liquid. In the sliding method, the ceramic powder having a mean grain size of 0.5 to 20 μm is contained in the liquid at the rate of 5 to 200 μg per 1 cm<SP>3</SP>of the liquid. Further, in the sliding body or the sliding method, the hardness of the DLC film is 10 GPa or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to a technical field related to a sliding body, a sliding method, and a mechanical device having the sliding body. Specifically, the sliding body has a sliding member that slides through a liquid, and a machine having such a sliding body. The present invention belongs to a technical field related to a sliding method of a sliding member that slides through a device (for example, a hydraulic pump, a hydraulic cylinder, a switching valve, and the like) and a liquid.

  Japanese Patent Laid-Open No. 10-184692 (Patent Document 1) discloses a water-lubricated seal or a water-lubricated bearing that includes a rotation-side member and a fixed-side member that is in sliding contact with the rotation-side member and uses water as a lubricating liquid. A TiN film is formed on the sliding surface of one member, and a diamond-like carbon (hereinafter also referred to as DLC) film or a chromium nitride (CrN) film is formed on the sliding surface of the other member, By forming at least the sliding surface of the other member with carbon fiber-containing polyether ether ketone (PEEK) or carbon fiber-containing tetrafluoroethylene resin (PTFE), a high seizure surface pressure and a low coefficient of friction can be obtained. Is described.

Japanese Utility Model Registration No. 3085999 (Patent Document 2) discloses that a member used in a humid environment is coated with DLC.
Japanese Patent Laid-Open No. 10-184692 Utility Model Registration No. 3085999

  DLC (diamond-like carbon) film is used for various sliding members as a film exhibiting self-lubricating properties in recent years, and is also used as a sliding film for mechanical devices that operate using water as a working medium or lubricating medium. .

  The DLC film is a film made of carbon (or H in some cases) and is inactive, but the sliding member (hereinafter also referred to as the DLC film sliding partner) of the DLC film reacts with the carbon. When an element that forms a compound (Fe, Ti, etc.) is contained, the reaction between the DLC film and the DLC film sliding mating member is promoted by heat generated or generated by sliding. Some wear may be accelerated.

  If the DLC film sliding mating material is coated with an inert material such as a TiN film as in the technique described in Patent Document 1, the above problem can be solved, but the shape of the DLC film sliding mating material (particularly the inner surface shape) ) May not always be possible to coat as described above, and it is also disadvantageous in cost to apply the coating as described above.

  The present invention has been made in view of such circumstances, and an object thereof is to have a sliding member that slides through a liquid, and the sliding of one sliding member in the sliding member. Even if the other sliding member (DLC film sliding partner) is made of a material that easily reacts with DLC, the sliding body has a DLC (diamond-like carbon) film formed on the surface. Provided are a sliding body in which the wear of the moving member is unlikely to occur, and a mechanical device having such a sliding body, and a sliding member having a DLC film formed on the sliding surface of one of the sliding members When the other sliding member (the DLC film sliding mating material) is made of a material that easily reacts with DLC, the sliding member is less likely to wear. Is to provide a method.

  As a result of intensive studies to achieve the above object, the present inventors have completed the present invention. According to the present invention, the above object can be achieved.

  The present invention thus completed and capable of achieving the above object relates to a sliding body, a sliding method, and a mechanical device having the sliding body, and the sliding body according to claims 1 to 5 (first to fifth inventions). The sliding method according to claims 6 to 10 (sliding method according to the sixth to tenth inventions), and the mechanical device according to claims 11 to 12 (the mechanical device according to the eleventh to twelfth inventions). Yes, it has the following structure.

That is, the sliding body according to claim 1 is a sliding body having a sliding member that slides through a liquid, and a diamond-like carbon film is formed on the sliding surface of one of the sliding members. The sliding body is characterized in that ceramic particles having an average particle diameter of 0.5 to 20 μm are contained in the liquid at a rate of 5 to 200 μg per 1 cm ^{3 of the} liquid [first invention].

  The sliding body according to claim 2 is the sliding body according to claim 1, wherein the ceramic is one or more of oxide ceramics, nitride ceramics, carbide ceramics, and boride ceramics [second invention]. .

The sliding body according to claim 3, wherein the oxide ceramic is one or more of Al ₂ O ₃ , SiO ₂ , ZrO ₂ , the nitride ceramic is one or more of Si ₃ N ₄ , TiN, and the boride. 3. The sliding body according to claim ₂ , wherein the ceramic is TiB ₂ [third invention].

  The sliding body according to claim 4 is the sliding body according to any one of claims 1 to 3, wherein the diamond-like carbon film has a hardness of 10 GPa or more [fourth invention].

  The sliding body according to claim 5 is the sliding body according to any one of claims 1 to 4, wherein the sliding surface of the other sliding member in the sliding member is made of a material containing Fe of 50 at% or more. There is [fifth invention].

The sliding method according to claim 6 is a sliding member that slides through a liquid, and a diamond-like carbon film is formed on a sliding surface of one of the sliding members. In sliding the moving member, the liquid contains ceramic particles having an average particle size of 0.5 to 20 μm at a rate of 5 to 200 μg per 1 cm ^{3 of the} liquid [Sixth Method] invention〕.

  The sliding method according to claim 7 is the sliding method according to claim 6, wherein the ceramic is one or more of oxide ceramics, nitride ceramics, carbide ceramics, and boride ceramics. invention〕.

The sliding method according to claim 8, wherein the oxide ceramic is one or more of Al ₂ O ₃ , SiO ₂ , ZrO ₂ , the nitride ceramic is one or more of Si ₃ N ₄ , TiN, and the boron. 8. The sliding method according to claim 7, wherein the chemical ceramic is TiB ₂ [8th invention].

  The sliding method according to claim 9 is the sliding method according to any one of claims 6 to 8, wherein the hardness of the diamond-like carbon film is 10 GPa or more [9th invention].

  The sliding method according to claim 10, wherein the sliding surface of the other sliding member in the sliding member is made of a material containing 50 at% or more of Fe. It is a method [10th invention].

  A mechanical device according to an eleventh aspect is a mechanical device including the sliding body according to any one of the first to fifth aspects [11th invention].

  The mechanical device according to a twelfth aspect is the mechanical device according to the eleventh aspect, wherein the mechanical device is one of a hydraulic pump, a hydraulic cylinder, and a switching valve.

  The sliding body according to the present invention has a sliding member that slides through a liquid, and a DLC (diamond-like carbon) film is formed on the sliding surface of one of the sliding members. Even when the other sliding member (the DLC film sliding mating member) is made of a material that easily reacts with DLC, the sliding member is hardly worn. The sliding member can be suitably used, and the durability can be improved.

  According to the sliding method of the present invention, when the sliding member having the DLC film formed on the sliding surface of one of the sliding members is slid through the liquid, the other sliding member is slid. Even when the moving member (the DLC film sliding partner) is made of a material that easily reacts with DLC, it is possible to make the sliding member less likely to wear.

  According to the mechanical device having the sliding body according to the present invention, the sliding member is hardly worn and the durability is improved.

As a result of intensive investigations to achieve the above-mentioned object, the present inventors have a sliding member that slides through a liquid, and the sliding surface of one of the sliding members is the sliding member. In a sliding body on which a DLC (diamond-like carbon) film is formed, if the ceramic particles having an average particle size of 0.5 to 20 μm are contained in the liquid at a ratio of 5 to 200 μg per 1 cm ^{3 of the} liquid, the other sliding It has been found that even when the moving member (the DLC film sliding partner) is made of a material that easily reacts with DLC, the sliding member is less likely to be worn and the friction coefficient is lowered.

  The ceramic particles contained in the liquid have a sliding interface [between the sliding surface of the sliding body on which the DLC film is formed (that is, the surface of the DLC film) and the sliding surface of the DLC film sliding counterpart material] And selectively adheres to the surface of the DLC film sliding counterpart having a lower hardness than the DLC film. Thus, once the ceramic particles adhere to the surface of the DLC film sliding partner, the sliding becomes the DLC film vs ceramic, not the DLC film vs. DLC film sliding partner, and the DLC film on the sliding surface As a result, even if the DLC film sliding partner is made of a material that easily reacts with DLC, the sliding member (DLC film sliding counterpart) And the wear amount of the DLC film side sliding member), and the friction coefficient is lowered.

The present invention has been completed based on such findings. The sliding body according to the present invention thus completed is a sliding body having a sliding member that slides through a liquid. The sliding body of one of the sliding members has a diamond-like surface. A sliding body characterized in that a carbon (DLC) film is formed, and ceramic particles having an average particle size of 0.5 to 20 μm are contained in the liquid at a ratio of 5 to 200 μg per 1 cm ^{3 of the} liquid. There is [the first invention]. The sliding body according to the present invention is a sliding body having a sliding member that slides through a liquid and having a DLC film formed on the sliding surface of one of the sliding members. Even when the other sliding member (the DLC film sliding counterpart) is made of a material that easily reacts with DLC, the wear of the sliding member is difficult to occur, and the friction coefficient is low. It can be suitably used as a sliding body such as a device, and the durability and sliding smoothness can be improved.

  The ceramic particles contained in the liquid have an average particle size of 0.5 to 20 μm. When the average particle size of the ceramic particles is less than 0.5 μm, the ceramic particles have irregularities on the sliding interface. The effect of suppressing direct contact between the DLC film and the DLC film sliding mating material is low, and therefore the wear amount and friction coefficient of the sliding member cannot be sufficiently reduced. When the average particle size exceeds 20 μm, the ceramic particles are difficult to be introduced into the sliding interface, and as a result, do not adhere to the surface (sliding surface) of the DLC film sliding mating member, and therefore the wear amount of the sliding member This is because the friction coefficient cannot be sufficiently reduced. On the other hand, when the average particle size of the ceramic particles is 0.5 to 20 μm, the wear amount and friction coefficient of the sliding member can be sufficiently reduced. In order to reduce the wear amount and friction coefficient of the sliding member to a higher level, it is desirable that the average particle size of the ceramic particles is 2 to 10 μm.

The amount (ratio) of ceramic particles contained in the liquid is ^{5 to} 200 μg (5 to 200 μg / cm ³ ) per 1 cm ^{3 of the} liquid. When less than / cm ³ , there is almost no adhesion of ceramic particles to the surface (sliding surface) of the DLC film sliding mating member, and therefore the wear amount and friction coefficient of the sliding member should be sufficiently reduced. On the other hand, if the amount of ceramic particles exceeds 200 μg / cm ³ , the amount of wear increases and the coefficient of friction also increases. On the other hand, when the amount of ceramic particles is 5 to 200 μg / cm ³ , the wear amount and friction coefficient of the sliding member can be sufficiently reduced. In order to reduce the wear amount and friction coefficient of the sliding member to a higher level, the amount of ceramic particles is preferably 10 to 100 μg / cm ³ .

  In the sliding body according to the present invention, the sliding member slides through the liquid. That is, the sliding member slides with the liquid as a working medium or a lubricating medium (lubricant). The type of the liquid is not particularly limited, and various liquids can be used. However, the effect of the present invention is particularly exerted by a liquid such as water or alcohol having a low lubricating effect, and particularly water. In this case, the effect of remarkable wear suppression is exhibited.

  The ceramic particles to be contained in the liquid are not particularly limited as long as they are inert and have low reactivity with DLC, and various types can be used. One or more kinds of particles of physical ceramics, nitride ceramics, carbide ceramics, and boride ceramics can be used [second invention].

As the oxide ceramic particles, for example, one or more of Al ₂ O ₃ , SiO ₂ , ZrO ₂ particles can be used, and as the nitride ceramic particles, for example, Si ₃ N ₄ , TiN particles 1 For example, TiB ₂ particles can be used as the boride ceramic particles [third invention]. Of these, one or more of Al ₂ O ₃ , SiO ₂ , and ZrO ₂ particles and Si ₃ N ₄ particles exhibit particularly excellent effects, and their use is preferable.

In the sliding body according to the present invention, it is desirable that the hardness of the DLC film is 10 GPa or more [fourth invention]. That is, when relatively hard particles such as Al ₂ O ₃ , SiO ₂ , ZrO ₂ particles are used as ceramic particles, if the hardness of the DLC film is less than 10 GPa, there is a possibility that abrasive wear of the DLC film may occur. However, if the hardness of the DLC film is 10 GPa or more, the occurrence of abrasive wear of the DLC film can be suppressed. In order to more reliably suppress the occurrence of such abrasive wear of the DLC film, it is desirable that the hardness of the DLC film is 15 GPa or more.

  In the sliding body according to the present invention, as described above, ceramic particles adhere to the surface of the DLC film sliding mating member, and direct contact between the DLC film and the DLC film sliding mating material is suppressed. The amount of wear of the members (the DLC film sliding mating member and the DLC film side sliding member) is reduced, and the friction coefficient is lowered. The effect of suppressing wear of the DLC film due to the adhesion of ceramic particles to the surface of the DLC film sliding partner material is that the DLC film sliding partner material easily reacts with DLC, that is, an element that forms carbide by reacting with DLC. It is obtained when it is made of a material containing, particularly when it is made of a material containing 50 at% or more of Fe, or when the sliding surface of the DLC film sliding counterpart material is made of a material containing 50 at% or more of Fe, [5th invention]. A material containing 50 at% or more of Fe tends to cause a reaction between Fe and DLC, but a material having a Fe content of less than 50 at% does not cause much reaction between Fe and DLC. Examples of the material containing 50 at% or more of Fe include SUS310, SUS430, SKD61, SKD11, and SUJ2 in addition to stainless steel materials such as SUS304, SUS630, and SUS316.

  The DLC film sliding mating material and the sliding surface of the DLC film sliding mating material are materials that are difficult to react with DLC and hard to form carbides, such as Al materials, and are made of a material having a lower hardness than the DLC film. In this case, the wear of the DLC film sliding mating member is suppressed by the adhesion of the ceramic particles to the surface of the DLC film sliding mating material.

  Since the sliding body according to the present invention is less likely to cause wear of the sliding member, the sliding body can be suitably used as a sliding body for mechanical devices and the like, and the durability thereof can be improved. The mechanical device having the sliding body according to the present invention is excellent in durability because wear of the sliding member hardly occurs [11th invention].

  In the sliding body according to the present invention, the sliding member slides using liquid as a working medium or a lubricating medium. Various liquids can be used as the liquid, but as described above, the effect of the present invention is particularly exerted by a liquid such as water or alcohol having a low lubricating effect, and particularly in the case of water. Demonstrate the effect of suppressing wear. Therefore, the sliding body according to the present invention can be particularly suitably used for a mechanical device using water as a working medium or a lubricating medium, and the durability thereof can be improved. Examples of such mechanical devices include a hydraulic pump, a hydraulic cylinder, and a switching valve [12th invention].

The sliding method according to the present invention is a sliding member that slides through a liquid, and a DLC (diamond-like carbon) film is formed on the sliding surface of one of the sliding members. When the sliding member is slid, ceramic particles having an average particle size of 0.5 to 20 μm are contained in the liquid at a rate of 5 to 200 μg per 1 cm ^{3 of the} liquid. Sixth Invention]. As can be seen from the above-described knowledge, according to the sliding method of the present invention, the sliding member having the DLC film formed on the sliding surface of one of the sliding members is interposed via the liquid. When sliding, even if the other sliding member (the DLC film sliding partner) is made of a material that easily reacts with DLC, it is possible to make the sliding member less likely to wear, and the friction coefficient. Can be lowered.

That is, when a sliding member having a DLC film formed on the sliding surface of one of the sliding members is slid through the liquid, a ceramic having an average particle size of 0.5 to 20 μm is contained in the liquid. of the particles are contained in a proportion of the liquid 1 cm ³ per 5 to 200 [mu] g, even if the other slide member (DLC Makusurido mating member) is made of prone materials react with DLC, sliding The wear of the member is less likely to occur, and the friction coefficient is lowered. Ceramic particles contained in the liquid are introduced into the sliding interface, and selectively adhere to the surface of the DLC film sliding counterpart material having a lower hardness than the DLC film. Thus, once the ceramic particles adhere to the surface of the DLC film sliding mating member, the sliding becomes a DLC film vs ceramic, not a DLC film vs. DLC film sliding mating material, and the DLC film on the sliding surface As a result, even if the DLC film sliding partner is made of a material that easily reacts with DLC, the sliding member (DLC film sliding counterpart) And the wear amount of the DLC film side sliding member), and the friction coefficient is lowered.

In the sliding method according to the present invention, as described above, when the sliding member having the DLC film formed on the sliding surface of one of the sliding members is slid through the liquid, Ceramic particles having an average particle diameter of 0.5 to 20 μm are contained in the liquid at a rate of 5 to 200 μg per 1 cm ^{3 of the} liquid. Therefore, according to the sliding method according to the present invention, even when the other sliding member (the DLC film sliding counterpart) is made of a material that easily reacts with DLC, the sliding member is hardly worn. And the friction coefficient can be lowered.

  The reason why the average particle size of the ceramic particles contained in the liquid is 0.5 to 20 μm is that the average particle size of the ceramic particles is 0.5 to 20 μm in the sliding body according to the present invention. It is the same. As in the case of the sliding body according to the present invention, in order to reduce the wear amount and friction coefficient of the sliding member to a higher level, it is desirable that the average particle size of the ceramic particles is 2 to 10 μm.

The reason why the amount (ratio) of ceramic particles contained in the liquid is 5 to 200 μg / cm ³ is that the amount (ratio) of ceramic particles in the sliding body according to the present invention is 5 to 200 μg. This is the same reason as that of / cm ³ . As in the case of the sliding body according to the present invention, the amount of ceramic particles is preferably 10 to 100 μg / cm ³ in order to reduce the wear amount and friction coefficient of the sliding member to a higher level. .

  In the sliding method according to the present invention, the sliding member is slid through the liquid. As this liquid, as in the case of the sliding body according to the present invention, various liquids can be used, but the effect of the present invention is particularly exerted by a liquid such as water or alcohol having a low lubricating effect, In particular, it exerts a remarkable wear suppression effect in the case of water.

  The ceramic particles to be contained in the liquid are not particularly limited as long as they are inert and have low reactivity with DLC, and various types can be used. One or more particles of physical ceramics, nitride ceramics, carbide ceramics, and boride ceramics can be used [seventh invention].

As the oxide ceramic particles, for example, one or more of Al ₂ O ₃ , SiO ₂ , ZrO ₂ particles can be used, and as the nitride ceramic particles, for example, Si ₃ N ₄ , TiN particles 1 For example, TiB ₂ particles can be used as the boride ceramic particles [8th invention]. Of these, one or more of Al ₂ O ₃ , SiO ₂ , and ZrO ₂ particles and Si ₃ N ₄ particles exhibit particularly excellent effects, and their use is preferable.

  In the sliding method according to the present invention, it is desirable that the hardness of the DLC film is 10 GPa or more [9th invention]. The reason for this is the same as in the case of the sliding body according to the present invention. Furthermore, it is desirable that the hardness of the DLC film is 15 GPa or more.

  In the sliding method according to the present invention, the ceramic particles adhere to the surface of the DLC film sliding mating member and direct contact between the DLC film and the DLC film sliding mating material is suppressed. The amount of wear of the counterpart material and the DLC film side sliding member) is reduced, and the friction coefficient is reduced. The effect of suppressing wear of the DLC film due to adhesion of ceramic particles to the surface of the DLC film sliding partner material can be obtained when the DLC film sliding partner material is made of a material that easily reacts with DLC. When the material is made of a material containing at least 50% or when the sliding surface of the DLC film sliding partner material is made of a material containing 50 at% or more of Fe [10th invention].

  Examples of the present invention and comparative examples will be described below. The present invention is not limited to this embodiment, and can be implemented with appropriate modifications within a range that can be adapted to the gist of the present invention, all of which are within the technical scope of the present invention. include.

  A DLC film forming material was obtained by forming a DLC film on the surface of the base material via an underlayer and an intermediate layer using an unbalanced magnetron sputtering apparatus having a binary evaporation source.

  At this time, as a base material, a cemented carbide substrate (mirror polishing) is used in the case of producing a DLC film forming material for hardness measurement (film formation), and a DLC film forming material for a sliding test is produced (composition). In the case of a film, a sliding test specimen (disk) made of SUS630 stainless steel (heat treatment: H900, hardness: Hv400) was used. The sputtering apparatus was equipped with a quaternary evaporation source, and Cr, W and binary C were used for film formation.

The substrate was ultrasonically cleaned with ethanol, introduced into a sputtering apparatus, evacuated to a vacuum of 1 × 10 ⁻³ Pa or less, and then heated to about 300 ° C. for degassing. Thereafter, cleaning with Ar ions was performed while keeping the substrate temperature constant at around 200 ° C.

  After this ion cleaning, a film having a layer structure of Cr / Cr-C / DLC or Cr / W / WC / DLC was formed on the surface of the substrate to obtain a DLC film forming material. In addition, the film of the layer structure of Cr / Cr-C / DLC forms a Cr layer as a base layer on a base material, forms a Cr-C (Cr carbide) layer as an intermediate layer thereon, and further on it A DLC layer is formed. A film having a layer structure of Cr / W / WC / DLC is formed by forming a Cr layer as a base layer on a substrate, a W layer as a first intermediate layer thereon, and a W-layer as a second intermediate layer thereon. A C (W carbide) layer is formed, and a DLC layer is formed thereon.

Here, the thickness of the intermediate layer is about 0.2 μm in total, and the thickness of the DLC part (DLC layer) is 1 to 2 μm. The film formation conditions for forming the DLC layer were as follows: the input power to the target was 2.5 kW, and a gas mixture of Ar + CH ₄ (CH ₄ concentration: 10 vol%) was used under a total pressure of 0.6 Pa. The substrate bias was varied from 0 to 150 V to control the hardness of the DLC film.

  The DLC film forming material obtained by such film formation was subjected to measurement of film hardness and a sliding test.

At this time, the hardness of the film was measured using a micro Vickers hardness meter. The sliding test was performed by a ball-on-disk sliding test. This ball-on-disk sliding test is performed using a disk: DLC film forming material, a ball: 3/8 inch diameter SUS630 stainless steel (heat treatment: H900, hardness: Hv400), lubricating liquid: distilled water (liquid amount: about 80 cm ³ ). The ceramic particles were put into this lubricating liquid (distilled water) and slid at a sliding distance of 1000 m under a sliding speed of 0.5 m / s and a vertical load of 2 N. Then, the friction coefficient was measured at a sliding distance of 1000 m, and the wear amount of the ball and disk was measured after sliding for 1000 m to obtain the specific wear amount of the ball and disk.

  Here, the specific wear amount of the ball was a value obtained by dividing the wear volume of the ball (volume of the worn portion) by the product of the sliding distance and the vertical load. The specific wear amount of the disk was a value obtained by dividing the wear volume of the disk by the product of the sliding distance and the vertical load. The wear volume of the ball was calculated from the radius or diameter of the wear part of the ball. The wear volume of the disk was determined by measuring the cross-sectional area of the groove (wear mark) of the sliding track at four locations and multiplying by the track circumference.

  The method for obtaining the wear volume of the ball and the wear volume of the disk will be described more specifically with reference to the drawings. FIG. 1 is a schematic diagram showing an example of the ball after the sliding test. This figure is a perspective view. FIG. 2 is a schematic diagram showing an example of the disk after the sliding test. 2A is a top view, and FIG. 2B is a cross-sectional view of the groove (wear mark) portion shown in FIG. 2A. In FIG. 1, r represents the diameter of the ball, and d represents the diameter of the worn part of the ball. In the case of the ball shown in FIG. 1, the wear volume of the ball is calculated from r and d. In FIG. 2B, A indicates the cross-sectional area of the groove (wear scar). In the case of the disk shown in FIG. 2, the wear volume of the disk is obtained by measuring such A at four locations and multiplying the average value by the track circumference (circumference at the center of the groove).

  The DLC film forming material of the disk is a material corresponding to an example of one sliding member (sliding member having a DLC film formed on the sliding surface) in the sliding body and sliding method according to the present invention. SUS630 stainless steel of the above ball is a test piece made of a material corresponding to an example of the other sliding member (DLC film sliding mating material) in the sliding body and sliding method according to the present invention. Equivalent to. The distilled water of the lubricating liquid corresponds to an example of the liquid of the sliding member that slides through the liquid in the sliding body and sliding method according to the present invention. Among the ceramic particles, those having an average particle size of 0.5 to 20 μm correspond to examples of ceramic particles used (contained in the liquid) used in the sliding body and sliding method according to the present invention.

The result of the said test is shown to Tables 1-2. Incidentally, the unit in the column of the DLC ratio wear amount and the ball ratio wear amount in Table 1~2 (× 10-7mm3N-1m-1 ) , by the ^{(× 10 -7 mm 3 N -1} m -1) is there. The DLC specific wear amount is a specific wear amount of the DLC film forming material of the disk.

As can be seen from Table 1, in the case of No. 3A, ceramic particles are not put into the lubricating liquid (distilled water). On the other hand, in the case of No. 4A to 9A, ceramic particles having an average particle diameter of 2 μm are introduced into the lubricating liquid (distilled water) and contained at a rate of 10 μg per 1 cm ^{3 of the} distilled water. Compared to the case of No. 3A, the specific wear amount of the DLC film forming material of the disk (DLC specific wear amount) and the specific wear amount of the ball are small, and the friction coefficient is small.

In the case of No. 1B, ceramic particles with an average particle size of 0.3 μm are introduced into the lubricating liquid (distilled water) and contained at a rate of 10 μg per 1 cm ^{3 of the} distilled water. In this case, the DLC film is formed on the disk. The specific wear amount of the material (DLC specific wear amount), the specific wear amount of the ball and the friction coefficient are the same as in the case of No. 3A. In the case of No.7B to 8B, ceramic particles having an average particle size of 29 μm or 150 μm are introduced into the lubricating liquid (distilled water) and contained at a rate of 10 μg per 1 cm ^{3 of the} distilled water. The specific wear amount (DLC specific wear amount) of the DLC film forming material, the specific wear amount of the ball, and the friction coefficient are the same as in the case of No. 3A.

In the case of No. 2B to 6B, ceramic particles having an average particle size in the range of 0.5 to 20 μm (filled with an average particle size of 0.5 to 20 μm) are introduced into the lubricating liquid (distilled water) and 1 cm ^{3 of the} distilled water In this case, the specific wear amount of the DLC film forming material of the disk (compared to the case of No. 3A and the case of No. 1B and No. 7B to 8B) ( DLC specific wear amount) and the specific wear amount of the ball are small, and the friction coefficient is small.

In the case of No. 1C, ceramic particles having an average particle diameter of 4 μm are introduced into the lubricating liquid (distilled water) and contained at a rate of 1 μg per 1 cm ^{3 of the} distilled water. In this case, the DLC film forming material for the disk The specific wear amount (DLC specific wear amount), the specific wear amount of the ball and the friction coefficient are the same as in the case of No. 3A. In the case of No. 7C to 8C, ceramic particles having an average particle size of 4 μm are introduced into the lubricating liquid (distilled water) and contained at a rate of 250 μg or 500 μg per 1 cm ^{3 of the} distilled water. The specific wear amount of the DLC film forming material of the disk (DLC specific wear amount), the specific wear amount of the ball and the friction coefficient are the same as in the case of No. 3A.

In the case of No. 2C to 6C, ceramic particles having an average particle diameter of 4 μm are introduced into the lubricating liquid (distilled water), and the rate is within the range of 5 to 200 μg per 1 cm ^{3 of the} distilled water (5 to 200 μg / cm ³ ). In this case, the specific wear amount of the DLC film forming material of the disk is compared with the case of No. 3A and compared with the case of No. 1C or No. 7C to 8C. (DLC specific wear amount) and the specific wear amount of the ball are small, and the friction coefficient is small.

As can be seen from Table 2, in the case of No. 1D to 6D, ceramic particles having an average particle diameter of 4 μm are introduced into the lubricating liquid (distilled water) and contained at 7 μg per 1 cm ^{3 of the} distilled water. The hardness of the DLC film in the film forming material is changed. Compared to the DLC film hardness of 5 GPa or 7 GPa, the DLC film hardness is 12 GPa, 15 GPa, 20 GPa, or 25 GPa. The amount is small. In particular, the DLC specific wear amount is smaller as the hardness of the DLC film is higher.

  In the case of No. 1E to 6E, SUS304 stainless steel, Ti-6Al-4V (titanium alloy) or A5052 (aluminum alloy) is used as the ball material instead of SUS630 stainless steel. A sliding test was conducted for the case where ceramic particles having an average particle diameter of 4 μm were introduced into the lubricating liquid (distilled water) and the case where ceramic particles were not introduced. When any of the above materials is used as the ball, when the ceramic particles are charged, the specific wear amount (DLC specific wear amount) of the DLC film forming material of the disk and the ratio of the ball are compared with the case where the ceramic particles are not charged. Wear amount is small and coefficient of friction is small.

In the case of No. 2A in Table 1, ceramic particles having an average particle diameter of 4 μm are introduced into the lubricating liquid (distilled water) and contained at a rate of 10 μg per 1 cm ^{3 of the} distilled water. SUS630 stainless steel (heat treatment: H900, hardness: Hv400) is used instead of the DLC film forming material, and the specific wear amount of the disk (SUS630 stainless steel) and the specific wear amount of the ball in this case are extremely large. The friction coefficient is extremely large.

  In the case of No. 1A in Table 1, SUS630 stainless steel (heat treatment: H900, hardness: Hv400) is used instead of the DLC film forming material as the material of the disk in the lubricating liquid (distilled water), and the lubricating liquid ( Distilled water) is not charged with ceramic particles (other than that). In this case, the specific wear amount of the disk (SUS630 stainless steel) and the specific wear amount of the ball are extremely large, and the friction coefficient is extremely large.

  In the sliding body according to the present invention, the DLC film is formed on the sliding surface of one of the sliding members that slide through the liquid, and the other sliding member (the DLC film sliding partner) is formed. Even if the material is made of a material that easily reacts with DLC, it is difficult for the sliding member to be worn. Therefore, it is preferably used as a sliding body for a mechanical device such as a hydraulic pump, a hydraulic cylinder, or a switching valve. It is useful because of its improved durability. In the sliding method according to the present invention, the DLC film is formed on the sliding surface of one of the sliding members that slide through the liquid, and the other sliding member (DLC film sliding) Even if the mating material is a sliding body made of a material that easily reacts with DLC, it is possible to make the sliding member less likely to wear, and therefore, the durability of the sliding body is improved and useful.

It is a schematic diagram which shows an example of the ball | bowl after a sliding test. FIG. 2A is a schematic view showing an example of a disk after a sliding test, and FIG. 2A is a top view, and FIG. 2B is a cross-sectional view of the groove shown in FIG. is there.

Claims (12)

In a sliding body having a sliding member that slides through a liquid, a diamond-like carbon film is formed on the sliding surface of one of the sliding members, and the average particle size in the liquid A sliding body comprising 0.5 to 20 μm ceramic particles in a ratio of 5 to 200 μg per 1 cm ^{3 of the} liquid.   The sliding body according to claim 1, wherein the ceramic is one or more of oxide ceramics, nitride ceramics, carbide ceramics, and boride ceramics. The oxide ceramic is at least one of Al ₂ O ₃ , SiO ₂ and ZrO ₂ , the nitride ceramic is at least one of Si ₃ N ₄ and TiN, and the boride ceramic is TiB _2. 2. The sliding body according to 2.   The sliding body according to claim 1, wherein the diamond-like carbon film has a hardness of 10 GPa or more.   The sliding body according to any one of claims 1 to 4, wherein a sliding surface of the other sliding member in the sliding member is made of a material containing 50 at% or more of Fe. When sliding a sliding member that slides through a liquid and having a diamond-like carbon film formed on the sliding surface of one of the sliding members, the liquid A sliding method characterized by containing ceramic particles having an average particle size of 0.5 to 20 μm in a ratio of 5 to 200 μg per 1 cm ^{3 of the} liquid.   The sliding method according to claim 6, wherein the ceramic is one or more of oxide ceramics, nitride ceramics, carbide ceramics, and boride ceramics. The oxide ceramic is at least one of Al ₂ O ₃ , SiO ₂ and ZrO ₂ , the nitride ceramic is at least one of Si ₃ N ₄ and TiN, and the boride ceramic is TiB _2. 7. The sliding method according to 7.   The sliding method according to claim 6, wherein the diamond-like carbon film has a hardness of 10 GPa or more.   The sliding method according to any one of claims 6 to 9, wherein a sliding surface of the other sliding member in the sliding member is made of a material containing 50 at% or more of Fe.   A mechanical device comprising the sliding body according to claim 1. The mechanical device according to claim 11, wherein the mechanical device is one of a hydraulic pump, a hydraulic cylinder, and a switching valve.

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