JPH0994911A - Rigid carbon film molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability under highly loading by coating a rigid carbon film (a diamond-like carbon film) on the surface of a steel base metal by putting a WC film between them. SOLUTION: At first a WC film 2 is formed on a surface of a steel base material 1, and a rigid carbon film 3 is formed on the WC film 2. The steel base metal is martensitic stainless steel, precipitation hardening stainless steel or SUJ2, M50, etc., and the WC film 2 is formed by using, for example, a magnetron sputtering apparatus. Further, the rigid carbon film 3 is formed by an ion plating method wherein, for example, hydrocarbon gas is introduced into a vacuum vessel, d.c. voltage is impressed between two poles of electrodes to generate glow discharge, and coating treatment is carried out under the discharge. When the WC film is made to lie as an intermediate layer between the rigid carbon film 3 and the steel base metal 1, adhesion is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard carbon film molded body which can be applied to sliding members and rolling bearings and has a hard carbon film (diamond-like carbon film) coated on the surface of a steel base material. Is.

[0002]

2. Description of the Related Art Conventionally, in sliding parts and rolling parts which are required to have high durability under high load, the surface of a steel base material is coated with a hard carbon film.

However, when the hard carbon film is directly coated on the surface of the steel base material, there is a problem that the hard carbon film is separated from the surface of the steel base material due to a difference in thermal expansion coefficient and the like.

Therefore, conventionally, by interposing an organic silicon compound or SiC-based intermediate layer between the steel base material and the hard carbon film, the adhesion between the steel base material and the hard carbon film is improved. It has been proposed to improve the durability under high load (JP-A-7-41779).

However, this conventional one is still insufficient in durability under high load.

Therefore, the present invention is more than the conventional one.
It is intended to further improve the durability under high load.

[0007]

According to the present invention, a WC film is interposed between a steel base material and a hard carbon film.

As described above, when the WC film is interposed as the intermediate layer between the steel base material and the hard carbon film, S is used as the intermediate layer.
Adhesion is improved and durability under high load is improved as compared with the conventional one using iC type. This is Si
When coating a C-based material, in addition to SiC, SiO ₂
It is presumed that an intermediate-form coating containing TiO2 is formed, which adversely affects the adhesion, whereas in the case of WC film formation, only WC is obtained and an oxide film that adversely affects adhesion is formed. It is presumed that this is because it is not formed.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, as a steel base material,
A martensitic stainless steel, a precipitation hardening stainless steel, or a steel material such as SUJ2 or M50 is used.

According to the present invention, as shown in FIG. 1, a WC film 2 is first formed on the surface of the steel base material 1, and a hard carbon film 3 is formed on the WC film 2. There is.

The WC film 2 can be formed, for example, by using a magnetron spalling device.

Further, the hard carbon film 3 is produced, for example, by introducing a hydrocarbon gas into a vacuum container, applying a DC voltage between the electrodes of two electrodes to generate glow discharge, and subjecting the hard carbon film 3 to film treatment under the discharge. Can be formed by the ion plating method.

[Example] A WC powder having a thickness of 0.1 μm or less was formed by coating WC powder on the surface of a φ50 mm disk type steel base material with a magnetron sputtering device (input power during processing: 150 to 250 W). Form the intermediate layer of the membrane.

Next, a hard carbon film having a thickness of about 0.5 μm is formed on the intermediate layer by using an ion plating apparatus using C ₂ H ₂ (acetylene) gas.
The voltage at the time of processing is -1.2 kV.

A pinion disk type friction wear tester was used for the WC film formed on the intermediate layer formed as described above and the SiC film formed by the SiC film or the organic silicon compound on the intermediate layer. The result of the durability test is shown in FIG. The test conditions are as shown in Table 1.

[0016]

[Table 1]

As is clear from FIG. 2, in each steel material, when the intermediate layer is the WC film, the durability of the hard carbon film is significantly increased.

Next, the material of the inner and outer rings is SUS440C,
A hard carbon film with a thickness of about 0.5 μm was formed on the surface
FIG. 3 shows a result of comparison of atmospheric dust generation characteristics between an angular bearing coated with a WC film having a thickness of 0.1 μm or less interposed therebetween and a SiC type intermediate layer. The test conditions are as shown in Table 2.

[0019]

[Table 2]

As is apparent from FIG. 3, the amount of dust generated in the atmosphere is reduced by using the WC film as the intermediate layer. Further, when the intermediate layer was a WC film, film peeling did not occur after the test, but in the case of the SiC type, film peeling partially occurred.
When the WC film is used, the total amount of dust generated in the atmosphere is as small as 500 or less, and it can be said that it is suitable for a rolling bearing used in an environment such as a clean room where the generation of dust is unfavorable.

[0021]

EFFECTS OF THE INVENTION Since the hard carbon film molded body of the present invention is coated with the hard carbon film on the surface of the steel base material with the WC film sandwiched between them, the hard carbon film does not easily peel off and is durable under high load. Good property.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a hard carbon film molded body of the present invention.

FIG. 2 is a graph showing the results of a durability test.

FIG. 3 is a graph showing the results of an atmospheric dust emission characteristic test.

[Explanation of symbols]

 1 Steel base material 2 WC film 3 Hard carbon film

Claims (1)

[Claims] 1. A hard carbon film molded body in which a hard carbon film is coated on the surface of a steel base material with a WC film interposed therebetween.