JP2778265B2 - Lubrication member for vacuum - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for modifying the surface of a lubricating member used in a vacuum such as in space or in various kinds of vapor deposition devices and analytical instruments. The present invention relates to a vacuum lubricating member suitable for being used in a field where a long life of the agent is required.

[0002]

2. Description of the Related Art As a conventional vacuum lubricating member, for example, SUS 44, which is a martensitic stainless steel, is used.
A base material is made of 0C, SUJ2 which is a high chromium bearing steel, or a titanium alloy, and the base material is degreased.
For example, a method of depositing molybdenum disulfide (MoS ₂ ) by physical vapor deposition using a high-frequency sputtering device or a method of applying and depositing various kinds of fired films have been used.

[0003]

However, in such a conventional vacuum lubricating member, even when the MoS ₂ film is formed by sputtering, which is the most basic technique, the contact surface pressure exceeds 800 MPa. Under such a high surface pressure, the life was limited to 500,000 slidings at most.

On the other hand, in the future, application to long-term use members such as vacuum lubrication members used in space stations and the like requires a sliding life of 5 million times even under such a high surface pressure. Therefore, there is a problem that it is difficult to guarantee the life with the current technology.

In order to solve such a problem, conventionally,
Studies on the components of solid lubricants have been conducted (for example, see JP-A-60-231457 and JP-A-61-255998).
And Japanese Unexamined Patent Publication No. Sho 63-215578) slightly disclose the technology for modifying the surface of a substrate.
The issue was only seen, and was not considered much.

Therefore, there is a problem that a vacuum lubricating member used for a space station or the like can be used for a long time even when sliding under a high surface pressure, and it is desired to extend the sliding life. there were.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is intended to provide a lubricating member for vacuum used in a vacuum such as in outer space, a vapor deposition apparatus, and an analytical instrument. It is an object of the present invention to significantly extend the life of the attached solid lubricant.

[0008]

According to the present invention, a molybdenum sulfide-based lubricant is contained on the surface of a base material in space or vacuum.
In a vacuum lubricating member used by attaching a solid lubricant, a configuration was used in which a coating containing silicon and oxygen as main components was formed on the base material surface as an underlayer of the solid lubricant containing the molybdenum sulfide-based lubricant . In the embodiment, the surface of the base material before the formation of the film containing silicon and oxygen as a main component is oxidized. The configuration of the invention relating to the member is used as means for solving the above-mentioned conventional problems.

As a result of repeating various experiments, the present inventor has found that a molybdenum sulfide-based lubricant adhered to the surface of a base material is contained.
In order to greatly extend the life of solid lubricants, it is necessary to form an underlayer with good adhesion to the solid lubricant applied to the substrate surface before attaching the solid lubricant to the substrate surface After considering various considerations of the underlayer from the view that it is desirable, by forming an amorphous undercoat mainly containing silicon and oxygen on the surface of the base material, there is a demand in the immediate space industry. It was confirmed that a vacuum lubricating member capable of guaranteeing a sliding life of 5 million times was obtained.

In forming the above-mentioned amorphous undercoat containing silicon and oxygen as main components on the surface of the base, the surface of the base before the formation of the undercoat is oxidized. It was confirmed that the adhesion of the coating to the heat history was further improved.

In the lubricating member for vacuum according to the present invention, the surface of the base material can be oxidized by an oxidizing salt bath treatment, and another oxidizing treatment can be used. As a method for forming an amorphous film containing silicon and oxygen as main components, ion plating can be used, or another method such as sputtering or salt bath treatment can be used.

[0012]

In the lubricating member for vacuum according to the present invention,
Forming a coating mainly composed of silicon and oxygen on the surface of the base material as an underlayer of a solid lubricant containing a molybdenum sulfide-based lubricant ,
Since the solid lubricant is adhered on the undercoat, the adhesion of the solid lubricant to the substrate surface via the undercoat is extremely good, and the molybdenum sulfide
The life of the solid lubricant including the system lubricant is greatly prolonged.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vacuum lubricating member according to the present invention will be described below.

In this embodiment, the case where the base material of the vacuum lubricating member is made of a titanium alloy is described.

Therefore, first, a titanium alloy (Ti-6% Al
-4% V) to prepare a pin disk test piece, and in order to oxidize the test piece, an oxide salt bath containing potassium carbonate (KCO ₃ ) as a main component was applied. The conditions for the treatment with the oxide salt bath are 615 ° C. for 16 hours.

Next, using silica glass as a target,
An SiOx coating having a thickness of about 0.3 μm and containing silicon and oxygen as main components was formed on the surface of the titanium alloy test piece using an arc discharge type ion plating apparatus.

For comparison, SUS440C, S
Pin-on-disk test pieces were prepared using UJ2, and no surface treatment was performed on these test pieces.

Then, the test piece of the invention example and the test piece of the comparative example (including a titanium alloy test piece without surface treatment).
Was evaluated by a pin-on-disk test in a vacuum.

Table 1 shows a list of attempted substrates. Although there are three types of the present invention, they differ only in the surface roughness of the surface.

[0020]

[Table 1]

Next, in order to confirm the effect of applying a solid lubricant to each substrate surface in Table 1, the most basic MoS ₂ film was used as a solid lubricant to a thickness of 1 μm using a high-frequency sputtering device. And evaluated whether or not there was a difference in the life of the solid lubricant by the above-mentioned pin / disk tester. Table 2 shows other conditions.

[0022]

[Table 2]

The surface pressure under these conditions is 890 MPa for a Ti alloy substrate and 1100 MPa for a SUS or SUJ substrate. The difference in surface pressure in this case is due to the difference in elastic modulus of the substrate.

The results are shown in FIG. 1. As is clear from FIG. 1, the conventional technique has a life of 600,000 times or less when any of the base materials is used. It has achieved a long life of 600,000 times, and 5 million times under optimal conditions.

Next, in the case of a test having a large slip ratio such as the pin / disk test used in the embodiment of the present invention, firing with an organic binder containing molybdenum disulfide as a main component, which is said to have poor characteristics, is performed. Using the film, a Ti alloy treated in the same manner as in the above-described embodiment of the present invention as a base material and a case where no treatment was performed were evaluated. Organic fired film used in this example is a commercially available sintered film using polyimide, polyamide as <br/> binder over. FIG. 2 shows the evaluation results in this case.

In the case of the fired film, the results vary considerably. Therefore, the test was performed three times, and the range of the variations was shown in the figure.

As is evident from the results shown in FIG. 2, when the treatment according to the present invention is performed, the life of the solid lubricant is clearly improved as compared with the case where the surface is not treated, and at the worst is about 600 times or more. The service life was confirmed.

As is evident from the above examples, the use of the surface modification technique according to the present invention on the surface of a substrate has a great effect on improving the life of the solid lubricant attached to the surface. FIG. 3 shows the result of subjecting the surface to X-ray diffraction (thin film method).

It is clear from the results shown in FIG. 3 that, in the treatment of the present invention, the film S containing silicon and oxygen as main components was formed.
The surface-forming oxide formed in the oxidation treatment in the previous step of forming the iOx film is not TiO ₂ but Ti ₂ O, which is an oxide in an unstable state. Further, the SiOx coating on the surface is not observed in the X-ray, and is considered to be amorphous.

Although the interaction between the surface coating and the solid lubricant is not clear, due to some surface chemical reaction,
Because the bonding force between the bottom layer of the fixed lubricant and the base material increases,
It is estimated that the life of the solid lubricant is extended.

Although the embodiment describes the case where a Ti alloy is used as the base material, the material of the base material is not particularly limited since the present invention focuses on the modification technique by surface coating. It is clear.

Further, in the above embodiment, the case where an oxide salt bath treatment is used as the surface oxidation method in the previous step is shown.
Other oxidation treatments can be used. Furthermore, various methods such as sputtering, ion plating, and salt bath treatment are used as a method for forming the amorphous undercoat containing silicon and oxygen as main components, and any method is sufficient. The effect is obtained.

[0033]

As has been described in the foregoing, according to the present invention, in the vacuum lubricating member used in the substrate surface to adhere the solid lubricant containing molybdenum disulfide-based lubricant, before
As a base layer of a solid lubricant containing the molybdenum sulfide-based lubricant , a coating composed mainly of silicon and oxygen was formed on the surface of the base material. Also provided is a lubricating member that can provide a long life of a solid lubricant. So, for example,
Not only can it be used for bearings in vacuum equipment such as electron microscopes, vapor deposition equipment and analytical equipment, but it is also extremely suitable as a lubricating member for space equipment, for which there is a strong demand for weight reduction. Brought.

[Brief description of the drawings]

FIG. 1 MoS by sputtering as a solid lubricant
FIG. 4 is an explanatory diagram showing the results of evaluating the life of a surface solid lubricant in a vacuum in the case of using No. ₂ .

FIG. 2 is an explanatory diagram showing the results of evaluating the life of a surface solid lubricant in a vacuum when a fired film made of an organic binder is used as the solid lubricant.

FIG. 3 is an explanatory diagram showing a surface X-ray diffraction result when a SiOx film is formed as an underlayer of a solid lubricant.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16C 33/10 F16C 33/10 D // C10N 10:12 40:00 50:08 80:00 (58) Field surveyed (Int. .Cl. ⁶ , DB name) C10M 103/06 C23C 8/10 C23C 8/40 C23C 14/08 C23C 14/16 F16C 33/10 C10N 10:12 C10N 40:00 C10N 50:08 C10N 80:00

Claims (2)

(57) [Claims] (1) sulfuric acid is applied to the surface of a substrate in outer space or vacuum.
A vacuum lubricating member used by attaching a solid lubricant containing a molybdenum fluoride-based lubricant , wherein the molybdenum sulfide
A lubricating member for vacuum, wherein a coating mainly composed of silicon and oxygen is formed on a surface of a base material as a base layer of a solid lubricant containing a system lubricant . 2. The vacuum lubricating member according to claim 1, wherein the surface of the base material before the coating containing silicon and oxygen as main components is formed is oxidized.