JPH01165761A - Member ensuring slight friction, seizing resistance and slight wear in atmosphere - Google Patents

Abstract

PURPOSE:To obtain the title member by forming an amorphous W alloy coating. CONSTITUTION:This member is obtd. by forming an amorphous W alloy coating and has a low coefft. of friction in an atmosphere, so it is hardly worn and has superior seizing resistance. An alloy contg. 11-75 atomic% W is preferably used as the amorphous W alloy. In case of <11% or >75% W content, the amorphous state is hardly produced and slight friction, seizing resistance and slight wear are hardly attained. An alloy contg., by atom, 10-75% W 30-50% Fe, 3-10% Ni and 7-20% Cr is especially preferably used as the amorphous W alloy. The amorphous W alloy coating can easily be formed by a sputter deposition method with a combined target consisting of an SUS304 disk and a thin, small W disk put on the SUS304 disk.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to low friction, anti-seizure, and low wear members in an atmosphere, and particularly those having a low coefficient of friction under both lubricated and dry conditions. It relates to a member that is small and has excellent wear resistance.

[Conventional technology] Bearings of various equipment, seal members, and other parts where sliding occurs between members have a low coefficient of friction and excellent seizure resistance, as well as excellent wear resistance and little wear due to sliding. This is required.

In order to meet these demands, there is a method of forming a film on the surface of the sliding part to improve friction and wear performance.If low friction and seizure resistance are important, gold, silver, lead, soot, etc. , metals such as indium and gallium, and soft coatings such as MO52, WS2, and fluororesin. If wear resistance is important, use a hard coating such as hard chrome plating or ceramics.

[Problems to be solved by the invention] As described above, the functions of the coating for improving low friction and anti-seizure performance and the coating for improving wear resistance are different, and the material that satisfies the performance of both is The current situation is that there are few.

Materials that have low friction, seizure resistance, and wear resistance have a wide range of practical applications as excellent sliding coatings. Therefore, the friction coefficient is small in the atmosphere, the burnout load is large,
Furthermore, it has been desired to develop a member with low frictional properties, anti-seizure properties, and low abrasion properties that can be provided at a low cost and which has a small amount of wear due to friction.

[Means for Solving the Problems] The member of the present invention that exhibits low friction, seizure resistance, and low wear in an atmosphere is characterized by being coated with an amorphous coating of W (tungsten) alloy.

Normally, alloys are crystallized in the solid state, but if you apply a method that does not create long-period regularity in the atomic arrangement during the solid formation process, such as by limiting the alloy composition and solidifying it by ultra-rapid cooling from the molten state, the crystal structure An amorphous structure resembling that of a liquid is obtained, and such an alloy is called an amorphous alloy.

Amorphous alloys are mostly homogeneous single-phase alloys of supersaturated solid solutions, have higher strength than conventional practical metals, and exhibit various properties, including very high corrosion resistance, depending on their composition. The present inventors have conducted research to utilize the characteristics of such amorphous alloys, and have found that W-based amorphous alloys have the unique property of having a low coefficient of friction in an atmosphere, and therefore less wear. They discovered this and completed the present invention.

[Function] The W-based amorphous alloy has a small friction coefficient in the atmosphere and a large burnout load.

In addition, it has high hardness and extremely high wear resistance, and the amount of wear due to friction is extremely small.

Therefore, a member coated with an amorphous W alloy coating has extremely low friction, seizure resistance, and low abrasion.

[Example] Examples of the present invention will be described below.

The member of the present invention is formed by applying an amorphous coating of W alloy.

As a W-based amorphous alloy, W is contained in an amount of 11 to 75 atomic%.
Even if the preferred 6W content is less than 11 atom % or more than 75 atom %, it is difficult to become amorphous and it is difficult to achieve low friction, seizure resistance, and low abrasion.

Particularly preferable W-based amorphous alloys include, in atomic %, W: 10 or more and 75 or less Fe: 30 or more and 50 or less Ni: 3 or more and 10 or less Cr: 7 or more and 20 or less It is a low-friction amorphous alloy containing

The above composition can be easily obtained by a sputter deposition method using a composite target consisting of a 5US304 disk and a thin, small W disk placed on top of the disk. As a result of investigating the range of amorphous composition by changing the number and size of W disks in such a composite target, we found that an amorphous structure is formed when the W content is between about 10 atomic percent and about 75 atomic percent. I understand.

In addition, as a W-based amorphous alloy that can be used for the purpose of the present invention, the present applicant has filed a patent application No. 60-510.
W is 10 to 75 with the following ■ that was proposed in issue 36.
Also included are those containing atomic percent.

■ Contains Ta and one or more elements selected from the group consisting of Ti% Zr and Nb% W, with the remainder essentially consisting of Ni, with a Ta content of 10 atomic% or more, An amorphous alloy in which the content of one or more elements selected from Ta is 15 to 80 atomic %.

■ Ta, one or more elements selected from the group consisting of Ti, Zr% Nb, and W, and Fe and/or C
O, the remainder is essentially Ni, and the content is T.
a and 1 selected from the group consisting of Ti, Zr, Nb and W
an amorphous alloy in which the content of the species or two or more species is 15 to 80 atomic %, Ta is 10 atomic % or more, Fe and/or CO is 75 atomic % or less, and Ni is 7 atomic % or more .

Such a W-based amorphous alloy has low friction and
In addition to seizure resistance and low abrasion properties, it also exhibits extremely high corrosion resistance even in harsh corrosive environments that contain hydrochloric acid, nitric acid, or even oxidizing agents.

In the present invention, if the film thickness of the W-based amorphous coating film is thin, a sufficient property improvement effect can be obtained;
Even if the film is thick, no improvement in characteristics can be expected, resulting in increased costs, and the problem of film peeling occurs.

Therefore, the thickness of the W-based amorphous coating film is appropriately determined depending on the scale of the member and the purpose of use, within a range that provides sufficient characteristics.

The method for forming the W-based amorphous coating film is not particularly limited to the sputter deposition method, and various other methods may be used.

Note that the base material of the member to which the W-based amorphous coating is applied is not particularly limited, and may be any of metals, ceramics, resins, etc.

An experimental example will be explained below.

Experimental Example 1 5US304 stainless steel bottles and disks were coated with a W-based amorphous coating with the following composition by sputtering (film thickness: 10 μm), and each sample and the uncoated sample were subjected to a friction test (lubrication conditions) using the following method. below) was performed.

As a comparative example, similar bottles and disks were prepared except that they were coated with a Ta-based amorphous coating, and a friction test was conducted in the same manner. Additionally, the same tests were conducted on uncoated 5US304 bottles and discs.

W-based amorphous composition (atomic %) W: 50% Fe: 38.2% Ni: 4.2% Cr: 9.6% Ta-based amorphous composition (atomic %) Ta: 50% Fe: 36.2% Ni: 4.2% Cr: 9.6% Experimental equipment: TT600A type friction tester (3-bin on-board)
Disk type) Test piece: 3 bottles and disk type Experimental conditions: Friction temperature = in SAE #20 engine oil
60°C Friction area: 0.59 cm' Load and speed: Changed according to the diagram shown in FIG. The experiment was conducted for 5 minutes for each condition.

Measurement items: Burnout load (the point where the friction coefficient suddenly increased was defined as the burnout point), friction coefficient measurement sample materials and combinations were as shown in Table 1.

The results are shown in Table 1 and Figure 2.

Table 1: When the surface condition after the test was observed using an optical microscope, running traces were observed in some parts of the surface coated with W-based amorphous, but otherwise there was no damage.
It was in good condition. .

Experimental Example 2 A SUS304 stainless steel member was subjected to a Fretting test (dry conditions), and the average coefficient of friction and amount of wear were measured. The results are shown in Table 2.

W-based amorphous composition (atomic%) W: 22% Fe:61% Ni: 3% Cr: 14% Ti-based amorphous composition (atomic %) Ti: 37% Fe: 46% Ni: 5% Cr: 14% Fretting test conditions are as follows.

Load: 14N Speed: 11000rpm Amplitude: Approximately 50μm From the results shown in Table 2, it can be seen that the members coated with the W-based amorphous coating as in the present invention have a low coefficient of friction in the atmosphere under both lubricated and dry conditions. It is clear that the material has low corrosion resistance and excellent seizure resistance and abrasion resistance.

[Effects of the Invention] As described in detail above, according to the present invention, a member is provided which has a small coefficient of friction in an atmosphere, has little wear, and has excellent seizure resistance. Furthermore, since the member of the present invention is coated with an amorphous W alloy, it also has excellent corrosion resistance. Therefore, it is extremely suitable as a bearing for various devices, a stage for an electron microscope, and as a sealing material.

[Brief explanation of the drawing]

FIG. 1 is a load diagram of the friction test in Experimental Example 1, and FIG. 2 is a graph showing the test results in Experimental Example 1. Agent Patent Attorney Tsuyoshi Shigeno

Claims (1)

[Claims] (1) A member having low friction, seizure resistance, and low wear in an atmosphere, characterized by being coated with an amorphous tungsten alloy coating.