JP5118906B2 - Sliding structure - Google Patents

Description

  The present invention includes a pair of sliding members in which a hard carbon film is formed on at least one of the sliding surfaces that slide relative to each other, and a lubricant present between the pair of sliding members, In particular, the present invention relates to a sliding structure capable of reducing a friction coefficient and improving wear resistance of a pair of sliding members.

  In recent years, there has been an interest in energy issues and environmental issues surrounding machinery. In today's society, where energy sources depend on oil and nuclear power, the depletion of energy resources is a matter of concern. The 20th century was an era of mass production and mass consumption, but in the 21st century it is important to use limited energy efficiently.

  One energy loss in machines is friction loss. A machine always has a sliding surface and generates friction, and reducing the friction leads to a reduction in energy consumption. Friction reduction is achieved by preventing direct contact between the two surfaces by the lubricant and reducing shear resistance. Many machines still use lubricants, and research on lubricants is actively conducted.

  On the other hand, hard carbon coatings such as amorphous carbon coatings, carbon nitride coatings, and diamond coatings are attracting attention as materials for reducing friction, and the friction of sliding members can be reduced by applying these coatings to sliding surfaces.・ Improved wear resistance.

  However, as engine parts, for example, automobile engine parts have recently been remarkably improved in performance due to high output and high rotation. Along with this, in a sliding member used in an engine, the performance improvement is limited only by applying the hard carbon coating on the sliding surface. Therefore, it is necessary to propose a sliding structure with more excellent sliding characteristics in consideration of the optimum combination of the sliding member and the lubricant.

  As an example, a sliding member coated with a hard carbon film, and a lubricating oil to which an ashless adjusting agent, an extreme pressure additive, a nonionic surfactant and the like are supplied to the surface of the sliding member are added. Have been proposed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2005-3094

  In the research so far, the lubricant supplied to the sliding member on which the hard carbon film is formed is lubricated with mineral oil, synthetic oil, etc., because a stable boundary lubricating film can be formed on the sliding surface. It is common to use oil as a base oil, and it has been common to improve the sliding characteristics by adding a plurality of additives to the lubricating oil as in the sliding structure described in Patent Document 1. .

  However, even when a lubricant containing the above additives is used, it cannot always be said that the friction coefficient is sufficiently reduced and the wear resistance is improved. Under a dynamic environment, the sliding surface has a high surface pressure, and it may be difficult to say that the sliding characteristics are sufficient. In addition, the lubricant must be mixed with an appropriate amount of an additive capable of exerting an effect while taking into account the viscosity change, and must be blended and adjusted in the lubricant. As the amount increased, the cost of the lubricant tended to increase.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to reduce the friction coefficient and wear resistance easily and inexpensively even under severe sliding environments such as high surface pressure. It is in providing the sliding structure which can improve property.

  In view of the above-mentioned problems, as a result of intensive studies, the inventors focused on water, not an oil agent, as a main ingredient of a lubricant. And, as a result of repeated experiments using water as a lubricant, the friction coefficient can be dramatically reduced by adding a surfactant to the water, compared to the case of using conventional oil agents. New knowledge that it was possible to improve wear resistance.

  The present invention is based on the above-mentioned new knowledge, and the sliding structure according to the present invention includes a pair of slides in which a hard carbon coating is formed on at least one of the sliding surfaces sliding relative to each other. A sliding structure including a moving member and a lubricant present between the pair of sliding members, wherein the lubricant includes at least water containing a surfactant.

  In the sliding structure according to the present invention, a hard carbon coating is formed on at least one sliding surface of a pair of sliding members that slide relative to each other. Further, a lubricant is present between the sliding surface of the sliding member on which the hard carbon film is formed and the sliding surface of the sliding member that slides on the sliding surface. In the present invention, “sliding relative to each other” means that at least one sliding member slides relative to the other sliding member, and relative sliding refers to linear motion, Sliding by rotational movement or a combination of these movements.

  As is apparent from experiments described later by the inventors, the friction of the sliding member on which the hard carbon film is formed by using a lubricant containing at least water contained in the surfactant as the lubricant. The coefficient can be reduced and the wear resistance can be improved. In addition, since the lubricant only needs to contain a surfactant in water, the raw materials are inexpensive, and furthermore, since the surfactant is ionized in water, it can be easily formulated. Such a sliding structure is excellent in productivity. In addition, water is the main agent (the largest proportion of the water constituting the lubricant is water), so it is less susceptible to viscosity changes due to temperature changes compared to oil-based ones. A stable boundary lubricating film can be formed on the surface.

  Examples of the surfactant to be contained in water include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant, and more preferably an anionic surfactant, a cationic surfactant, and a cationic surfactant. Either an ionic surfactant or a nonionic surfactant. By using any one of the above surfactants, one or both of reducing the friction coefficient of the sliding member and improving the wear resistance of the hard carbon coating formed on the sliding member can be achieved. it can.

  When a lubricant containing an anionic surfactant with respect to water is used in the sliding structure according to the present invention, the friction coefficient can be reduced and the wear resistance can be improved. The “anionic surfactant” referred to in the present invention is also referred to as an anionic surfactant, and is a surfactant that ionizes a hydrophilic group portion to an anion when dissolved in water. Examples of the anionic surfactant include fatty acid salts (soap), alpha sulfo fatty acid ester salts (α-SF), alkyl benzene sulfonates (ABS), linear alkyl benzene sulfonates (LAS), and alpha olefin sulfonates. (AOS), alkyl sulfate (AS), alkyl ether sulfate (AES), monoalkyl phosphate (MAP), alkane sulfonate (SAS) and the like. These types are not particularly limited as long as the friction coefficient and the wear resistance of the sliding member can be ensured to a desired level.

  Further, when the anionic surfactant is used, it is more preferable that the anionic surfactant is contained at least 0.5% by mass or more with respect to the water. By using water containing an anionic surfactant in the above range as a lubricant, not only can the wear of the sliding surface on which the hard carbon coating is formed be suppressed, but the friction coefficient of the sliding member can be further increased. Further reduction is possible. That is, when the content of the anionic surfactant is less than 0.5% by mass with respect to water, although the wear resistance is ensured, the friction coefficient of the sliding member tends to increase. Furthermore, the anionic surfactant is preferably contained in a content not higher than that soluble in water, and the content soluble in water varies depending on the type of the anionic surfactant exemplified above. . That is, even if the content is larger than this range, the anionic surfactant added to water does not ionize any more, so it cannot be said that further effects can be expected.

  When a lubricant containing a cationic surfactant with respect to water is used in the sliding structure according to the present invention, low friction can be expected as compared with conventional lubricants. Further improvement in the wear resistance of the sliding surface can be expected. In particular, as the content of the cationic surfactant increases, the friction coefficient can be increased while ensuring the wear resistance. The “cationic surfactant” referred to in the present invention is also referred to as a cationic surfactant, and is a surfactant that ionizes a hydrophilic group portion to a cation when dissolved in water. Examples of the cationic surfactant include alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, and amine salt systems. These types are not particularly limited as long as the wear resistance of the sliding member can be ensured to a desired level and a desired coefficient of friction can be obtained.

  Further, when the cationic surfactant is used, it is more preferable that the cationic surfactant is contained at least 1.0% by mass or more with respect to the water. By using water containing a cationic surfactant in the above range as a lubricant, a slide in which a hard carbon film is formed regardless of an increase in the friction coefficient of the sliding member accompanying an increase in the cationic surfactant. Surface wear can be reliably suppressed. That is, when the content of the cationic surfactant is less than 1.0% by mass with respect to water, the wear property of the hard carbon film tends to increase. Furthermore, it is preferable that the cationic surfactant contains not more than a content that can be dissolved in water, and the content that can be dissolved in water varies depending on the type of the cationic surfactant exemplified above. . That is, even if the content is larger than this range, the cationic surfactant added to water does not ionize any more, so it cannot be said that a further effect can be expected.

  When a lubricant containing a nonionic surfactant with respect to water is used in the sliding structure according to the present invention, the friction coefficient can be reduced and the wear resistance can be improved. The “nonionic surfactant” referred to in the present invention is also called a nonionic surfactant, and is a surfactant that ionizes a hydrophilic group portion into a nonion when dissolved in water. Nonionic surfactants include, for example, polyoxyethylene alkyl ether (AE), polyoxyethylene alkyl phenyl ether (APE), alkyl glucoside (AG), polyoxyethylene fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, fatty acid Examples include diethanolamide and fatty acid alkanolamide. These types are not particularly limited as long as the friction coefficient and the wear resistance of the sliding member can be ensured to a desired level.

  Furthermore, when the nonionic surfactant is used, the nonionic surfactant is more preferably contained at least 0.5% by mass or more with respect to the water. By using water containing a nonionic surfactant in the above range as a lubricant, it is possible to suppress wear of the sliding surface on which the hard carbon film is formed. More preferably, the nonionic surfactant is contained at least 10% by mass or more with respect to the water. In addition, when the content rate of an anionic surfactant is less than 0.5 mass% with respect to water, it exists in the tendency for abrasion of a hard carbon film to increase. Moreover, when it is less than 10% by mass, the friction coefficient tends to increase. Furthermore, it is preferable that the nonionic surfactant is contained in a water-soluble content or less, and the water-soluble content varies depending on the type of nonionic surfactant exemplified above. . That is, even if the content is larger than this range, the nonionic surfactant added to the water does not ionize any more, so it cannot be said that a further effect can be expected.

  The sliding structure according to the present invention has a hard carbon coating as compared with a base material on which the coating is applied, such as a coating obtained by crystallizing carbon such as a diamond coating or a coating containing an amorphous structure such as an amorphous carbon coating. If it is a hard carbon film, it will not be limited to gain. However, a more preferable hard carbon coating is an amorphous carbon coating (a coating made of Diamond Like Carbon: a DLC coating) or a carbon nitride coating (CNx coating). Moreover, an amorphous carbon nitride film is more preferable among the carbon nitride films. Since the surface of the coating is more active than the amorphous carbon coating, it is considered that a stronger boundary lubricating film can be formed during sliding. As a result, a lower friction coefficient can be obtained as compared with the amorphous carbon coating.

  When forming the hard carbon film described above on the surface of the base material of the sliding member, the film is formed by physical vapor deposition (PVD) using vacuum deposition, sputtering, ion plating, ion beam mixing, or the like. Alternatively, the film may be formed by chemical vapor deposition (CVD) utilizing plasma treatment or the like, or may be formed by a combination of these methods. In addition, when forming an amorphous carbon nitride film, which is a kind of DLC film, when forming a carbon nitride film (CNx film), in order to obtain more stable low friction characteristics, film formation and ion It is more preferable to form these films by an ion beam method based on a dynamic mixing method in which the implantation is performed simultaneously. Further, during such film formation, an additive element such as Si, Ti, Cr, Fe, Mo, W, or B may be included in the hard carbon film, and by adding such an element, the film The surface hardness can be adjusted.

  Further, when forming the hard carbon film on the surface of the sliding member, an intermediate layer made of silicon (Si) may be provided in order to increase the adhesion between the base material of the sliding member and this film. Further, chromium (Cr), titanium (Ti), or tungsten (W) may be used instead of silicon.

  Furthermore, if the base material on which the hard carbon film is formed has a material and surface hardness that can ensure adhesion to the hard carbon film during sliding, iron, non-ferrous metal, etc. There is no particular limitation, and the other sliding member that slides with this sliding member is also extremely low in surface hardness with respect to this hard carbon coating and is not easily worn when sliding. The material is not particularly limited.

  Further, the sliding structure according to the present invention is a circulating lubrication mechanism as a mechanism for arranging (supplying) the lubricant on the sliding member in order to allow the lubricant to stably exist between the pair of sliding members. Further, a mist lubrication mechanism or a bath lubrication mechanism may be further provided, and the mechanism is not particularly limited as long as the lubricant is stably supplied between the sliding members during sliding. Absent. Furthermore, if the lubricant does not hinder the action of the surfactant, an antioxidant, an antiwear agent, an extreme pressure agent, a friction modifier, a metal deactivator, a detergent, an antirust agent. It is also possible to add an agent, a foam detergent, and the like as appropriate.

  According to the sliding structure according to the present invention, even in a severe sliding environment such as a high surface pressure, the friction coefficient can be easily reduced at low cost and the wear resistance can be improved.

  Hereinafter, the present invention will be described by way of examples. In addition, this invention is not limited to the Example shown below.

(Example 1-1)
Of the pair of sliding members of the sliding structure according to the present invention, the following disk test piece is manufactured as one sliding member on which a hard carbon film is formed, and the other sliding member sliding with this sliding member As a member, the following ball test piece was manufactured.

<Disk specimen>
A disk-shaped silicon wafer S having a diameter of 50 mm, a thickness of 0.3 mm, and a circular surface (sliding surface) in a mirror surface state (100 plane orientation) was prepared as a base material on which a hard carbon film was formed. Then, using an ion beam mixing apparatus 10 (1X-30-30, manufactured by Hitachi, Ltd.) as shown in FIG. 1, an amorphous carbon nitride (CNx) film (hard carbon film) is formed on the surface of the circular portion of the silicon wafer S. ) Was formed. In the ion beam mixing method, since the mixing layer is formed between the substrate and the thin film (surface modified layer), there is no conventional substrate / film boundary, adhesion to the film, and composition of the film. This is a film forming method capable of surface treatment with excellent controllability.

  As shown in FIG. 1, the ion beam mixing apparatus 10 includes at least a vacuum chamber 11, a substrate holder 12, an assisting ion source and gas supply source 14, a sputter ion source 15, and a cryopump 16. The ion source is a sputter. Both of the ion source and the assist type are bucket types, the sputter ion source has an acceleration voltage of 1500 eV at the maximum, an ion current of 200 mA at the maximum, and an effective diameter of the ion beam of about 80 mm. The substrate holder 12 is configured to rotate during film formation and to change the angle between the ion beam and the substrate surface within a range of 0 ° to 90 °. Using such an apparatus 10, a film was formed as follows.

Specifically, as shown in FIG. 1, the holder 12 in the vacuum chamber 11 is arranged so that the circular surface of the silicon wafer S faces the carbon target T with a purity of 99.9999% arranged on the support base 13. A silicon wafer S was attached to the substrate. Thereafter, the pressure in the vacuum chamber 11 is adjusted to 2.0 × 10 ⁻⁴ Pa or less with a cryopump 16, and nitrogen ions gn (acceleration voltage 1 keV, ion current density μA / cm ² ) is applied to the silicon wafer for 5 minutes. Irradiation toward S and sputter cleaning was performed. Thereafter, the pressure in the vacuum chamber 11 is adjusted to 1.4 × 10 ⁻² Pa, and the carbon target T is irradiated with argon ions ga from the sputter ion source 15 to convert the carbon target T into carbon sputtered particles sc. The silicon wafer S was rotated at 4 rpm together with the holder 12, and an amorphous carbon nitride film (CNx film) having a thickness of 100 nm was formed on the circular surface of the silicon wafer.

<Ball specimen>
A silicon nitride sphere having a diameter of 8 mm and shown in Table 1 below was prepared, and a carbon nitride film was formed in a thickness of 200 nm on the surface of the sphere in the same manner.

<Lubricant>
A lubricant was prepared by adding sodium alkyl ether sulfate as water as the surfactant, alkyl ether sulfate (AES).

<Abrasion test>
A pin-on-disk friction tester 30 shown in FIG. 2 was used. The “pair of sliding members” according to the present invention indicates a disk test piece and a ball test piece.

  As a preliminary preparation for the wear test, the ball specimen B was ultrasonically cleaned with acetone and ethanol for 10 minutes each. Thereafter, the ball test piece B is removed from the main body of the testing machine, fixed to the ball holder 31, and after confirming that there is no scratch on the surface using an optical microscope (not shown), these are placed in a desiccator (not shown). The ball test piece B was dried. On the other hand, foreign matters such as dust on the surface (sliding surface) of the CNx film formed on the surface of the disk test piece D were removed by hand blow (not shown).

  Next, the disc test piece D was held by the disc holder 32, and the ball holder 31 to which the ball test piece B was fixed was attached to the main body of the testing machine so as to be integrated with the stage 33. Then, the lubricant was supplied to the holder 32 until the height reached 1 mm so that the lubricant L was always present on the surface of the disk test piece D during the test. Further, a ball test piece B is added to the surface of the CNx coating of the disk test piece D using a strain gauge 34 (Kyowa Dengyo Co., Ltd., KF-1-120-C1-16) bonded to the parallel leaf spring 34. The stage 33 was adjusted so that the value of the applied load was 1.0 N, and the ball test piece B was pressed against the disk test piece D.

Holding this pressed state, the motor 37 is driven to rotate the disk test piece D of the disk holder 32 through the coupling 38 so that the sliding speed is 1.26 × 10 ⁻² m / s. The frictional force at this time was measured with a strain gauge 34, and data was taken into a computer and recorded via a sensor interface (PCD-300A, manufactured by Kyowa Dengyo). And the friction coefficient was converted. The result is shown in FIG.

(Example 1-2)
A disk test piece D, a ball test piece B, and a lubricant L were prepared in the same manner as in Example 1-1. The difference from Example 1-1 is that a DLC film (HT-DLC (thick film, highly reliable DLC: manufactured by Japan IT Corporation)) is formed on the surface of the disk specimen D by plasma CVD. The friction coefficient was measured under the same friction test conditions as in Example 1-1, and the results are shown in FIG.

(Comparative Examples 1-1 to 7-1)
A disk test piece D, a ball test piece B, and a lubricant L were prepared in the same manner as in Example 1-1. The difference from Example 1-1 is a lubricant, and Comparative Examples 1-1 to 7-1 are, in place of the lubricant, base oil 5W-30, which is mineral oil, pure water, ethanol (C ₂ H ₅ OH), kerosene (kerosene), silicon oil, formaldehyde (HCONH ₂ : amide of formic acid), and hexane (C ₆ H ₁₄ ). And the friction coefficient was measured on the friction test conditions similar to Example 1-1. The result is shown in FIG.

(Comparative Examples 1-2 to 7-2)
As in Example 1-2, a disk test piece D, a ball test piece B, and a lubricant L were prepared. The difference from Example 1-2 is a lubricant, and the lubricants supplied in Comparative Examples 1-2 to 7-2 correspond to the lubricants in Comparative Examples 1-1 to 7-1 in order. ing. And the friction coefficient was measured on the friction test conditions similar to Example 1-2. The result is shown in FIG.

(Result 1 and Discussion 1)
From this test result, it was confirmed that the friction coefficient obtained using the CNx film tends to be lower than the friction coefficient obtained using the DLC film. This is presumably because the CNx film had higher activity than the DLC film, and a stronger boundary lubricating film was formed during sliding. When the kerosene of Comparative Example 4 and the hexane of Comparative Example 7 are lubricated, the friction coefficient obtained using the CNx coating is higher than that obtained using the DLC coating. This is because the shear resistance is larger than that.

  Further, under the lubricant containing the surfactants of Examples 1-1 and 1-2, a low friction coefficient was obtained for both the CNx film and the DLC film. This is because Examples 1-1 and 1-2 contain a surfactant, so that there are many unsaturated molecules and polar molecules in the surfactant compared to the others. It is thought that it is from.

(Example 2)
A disk test piece D, a ball test piece B, and a lubricant L were prepared in the same manner as in Example 1-1. The difference from Example 1-1 is a lubricant. The lubricant supplied in Example 2 is selected from alkane sulfonates as an anionic surfactant with respect to water, and sodium decane sulfonate. Is 0.5% by mass or more (specifically, 0.5% by mass, 1.0% by mass, 10% by mass, 20% by mass). And the friction coefficient was measured on the friction test conditions similar to Example 1-1. The condition different from that of Example 1-1 is that the sliding speed is set to 3.14 × 10 ⁻² m / s. The result is shown in FIG. Further, after the test is completed, each disk specimen D is taken out from the testing machine 30 and the cross-sectional area of the wear mark formed on the CNx film is obtained using an atomic force microscope (AFM), and the specific wear of this film is determined. The amount was calculated. The result is shown in FIG.

(Comparative Example 8)
In the same manner as in Example 2, a disk test piece D, a ball test piece B, and a lubricant L were prepared. The difference from Example 2 is that a water-only lubricant without adding the anionic surfactant to water and a lubricant containing 0.1% by mass of an anionic surfactant were prepared. is there. In the same manner as in Example 2, the friction coefficient and the specific wear amount were measured. The results are shown in FIGS.

(Result 2 and discussion 2)
As shown in FIG. 4, when 0.1 mass% of the anionic surfactant of Comparative Example 8 was contained, the friction coefficient was increased as compared with any case of Example 8. On the other hand, as shown in FIG. 5, the anionic surfactant of Comparative Example 8 was contained in an amount of 0.1% by mass, and the anionic surfactant of Example 2 was contained in an amount of 0.5% by mass or more. In any case, the specific wear amount decreased as compared with the case of water lubrication in Comparative Example 8, and the friction coefficient decreased as the content of the anionic surfactant was increased. From this result, by using a lubricant containing an anionic surfactant in water as a sliding structure lubricant, the wear of the CNx film (hard carbon film) formed on the surface of the sliding member is suppressed. In addition, it is considered that the friction coefficient can be further reduced by using a lubricant containing 0.5% by mass or more of an anionic surfactant.

(Example 3)
In the same manner as in Example 2, a disk test piece D, a ball test piece B, and a lubricant L were prepared. The difference from Example 1-1 is a lubricant, and the lubricant supplied in Example 3 is selected from alkyltrimethylammonium salts as cationic surfactants with respect to water. Is 1.0 mass% or more (specifically, 1.0 mass%, 10 mass%, 20 mass%). In the same manner as in Example 2, the friction coefficient and the specific wear amount were measured. The results are shown in FIGS.

(Comparative Example 9)
As in Example 3, a disk specimen D, a ball specimen B, and a lubricant L were prepared. The difference from Example 3 is that the water-only lubricant to which the cationic surfactant is not added and 0.1% by mass or 0.5% by mass of the cationic surfactant are added to water. This is the point where a lubricant was prepared. Then, as in Example 3, the friction coefficient and the specific wear amount were measured. The results are shown in FIGS.

(Result 3 and discussion 3)
As shown in FIG. 6, any of the surfactants containing the cationic surfactant has an increased coefficient of friction as compared with the water-lubricated one of Comparative Example 9, and the content of the cationic surfactant. The coefficient of friction tended to increase with increasing. On the other hand, as shown in FIG. 7, in Comparative Example 9, when the cationic surfactant was contained in an amount of 0.1% by mass and 0.5% by mass, the specific wear amount was higher than that in the case of water lubrication. Increased. However, as shown in Example 3, when the cationic surfactant was contained in an amount of 1.0% by mass or more, the specific wear amount was reduced as compared with any case of Comparative Example 9. From this result, by using a lubricant containing a cationic surfactant in water as a sliding structure lubricant, the wear of the CNx coating (hard carbon coating) formed on the surface of the sliding member is suppressed. I think it can be done.

Example 4
In the same manner as in Example 2, a disk test piece D, a ball test piece B, and a lubricant L were prepared. The difference from Example 1-1 is a lubricant, and the lubricant supplied in Example 3 is selected from polyoxyethylene alkyl ether as a nonionic surfactant with respect to water. This is that 0.5% by mass or more (specifically, 0.5% by mass, 1.0% by mass, 10% by mass, 20% by mass) of lauryl ether is contained. In the same manner as in Example 2, the friction coefficient and the specific wear amount were measured. The results are shown in FIGS.

(Comparative Example 10)
As in Example 3, a disk specimen D, a ball specimen B, and a lubricant L were prepared. The difference from Example 2 is that a water-only lubricant not containing the nonionic surfactant with respect to water and a lubricant containing 0.1% by mass of the nonionic surfactant were prepared. It is. Then, as in Example 3, the friction coefficient and the specific wear amount were measured. The results are shown in FIGS.

(Result 4 and Discussion 4)
As shown in FIG. 8, in Comparative Example 10, when 0.1% by mass of the nonionic surfactant was contained, the friction coefficient increased as compared with the case under water lubrication. Furthermore, in Example 4, when the nonionic surfactant was contained in an amount of 10% by mass or more, the friction coefficient decreased compared to other cases. On the other hand, as shown in FIG. 9, compared to Comparative Example 10, the amount of specific wear is reduced by using a lubricant containing 0.5% by mass or more of a nonionic surfactant as in Example 4. did. From this result, it can be seen from this result that when 0.5% by mass or more of the nonionic surfactant is contained, the wear of the CNx film (hard carbon film) formed on the surface of the sliding member is suppressed. Further, it is considered that when the nonionic surfactant is contained in an amount of 10% by mass or more, the friction coefficient of the sliding member can be further reduced.

  As mentioned above, although the embodiment of the present invention has been described in detail, the specific configuration is not limited to this embodiment, and even if there is a design change within a scope not departing from the gist of the present invention, they are not limited to the present invention. Is included.

  For example, in this example, a hard carbon film was formed on a silicon wafer as a base material of one sliding member. However, if the hard carbon film does not peel or crack when sliding, iron, etc. The metal material may be coated. Moreover, it is not necessary to form the hard carbon film on both sliding surfaces of the pair of sliding members, and the hard carbon film may be formed only on one of the sliding surfaces.

The figure for demonstrating the ion mixing beam apparatus which concerns on an Example. The figure for demonstrating the pin-on-disk friction testing machine which concerns on an Example. The figure which showed the result of the friction coefficient which concerns on Examples 1-1 and 1-2, Comparative Examples 1-1 to 7-1, and Comparative Examples 1-2 to 7-2. The figure which showed the result of the friction coefficient which concerns on Example 2 and Comparative Example 8. FIG. The figure which showed the result of the specific wear amount which concerns on Example 2 and Comparative Example 8. FIG. The figure which showed the result of the friction coefficient which concerns on Example 3 and Comparative Example 9. FIG. The figure which showed the result of the specific wear amount which concerns on Example 3 and Comparative Example 9. FIG. The figure which showed the result of the friction coefficient which concerns on Example 4 and Comparative Example 10. FIG. The figure which showed the result of the specific wear amount which concerns on Example 4 and Comparative Example 10. FIG.

Explanation of symbols

  10: Ion beam mixing device, 11: Vacuum chamber, 12: Holder, 13: Support base, 14: Assist ion source and gas supply source, 15: Sputter ion source, 16: Cryo pump, 30: Pin-on-disk friction test Machine: 31: Ball holder, 32: Disc holder, 33: Stage, 34: Strain gauge, 35: Parallel leaf spring, 37: Motor, 38: Coupling, B: Ball specimen (sliding member), D: Disc Test piece (sliding member), S: silicon wafer (base material), T: carbon target

Claims (8)

A slide provided with a pair of sliding members having a hard carbon film formed on at least one of the sliding surfaces sliding relative to each other, and a lubricant present between the pair of sliding members. Dynamic structure,
The sliding structure characterized in that the lubricant contains at least water contained in a surfactant.   The sliding structure according to claim 1, wherein the surfactant is an anionic surfactant.   The sliding structure according to claim 2, wherein the anionic surfactant is contained in an amount of at least 0.5 mass% with respect to the water.   The sliding structure according to claim 1, wherein the surfactant is a cationic surfactant.   The sliding structure according to claim 4, wherein the cationic surfactant is contained at least 1.0 mass% with respect to the water.   The sliding structure according to claim 1, wherein the surfactant is a nonionic surfactant.   The sliding structure according to claim 6, wherein the nonionic surfactant is contained at least 0.5 mass% with respect to the water.   The sliding structure according to claim 1, wherein the hard carbon coating is an amorphous carbon coating (DLC coating) or a carbon nitride coating (CNx coating).

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