JPH05186287A - Coated ceramic member and its production - Google Patents

Abstract

PURPOSE:To obtain a coated ceramic member having a coated layer of an amorphous carbon film with high hardness and a low coefficient of friction, showing excellent friction resistance and sliding characteristics. CONSTITUTION:An amorphous silicon middle layer having 50-5,000Angstrom film thickness is formed on the surface of a ceramic base by ion implantation deposition method and the silicon middle layer is coated with an amorphous hard carbon film having 1,000Angstrom to 3mum by PVD method or plasma CVD method to give the objective coated ceramic member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated ceramic member having excellent wear resistance and sliding resistance, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Ceramics have excellent properties that cannot be achieved by metals in terms of wear resistance, corrosion resistance, heat resistance, etc., so research into practical applications for mechanical parts and parts used at high temperatures is an active task. Is being promoted.

In recent years, in particular, attempts have been made to use ceramics in parts of electronic equipment and mechanical parts that slide at high speed in a non-lubricated state. However, since the hardness of ceramics is extremely high, there is a drawback that the mating material may be damaged or worn if the usage method is mistaken. Further, since the coefficient of friction (μ) of the ceramic itself is extremely high, frictional heat is generated to raise the temperature of the sliding portion, and there is a disadvantage that the coefficient of friction of the ceramic member is further increased due to the temperature rise.

In order to solve this problem, attempts have been made to modify the surface of the ceramic and reduce the friction coefficient without impairing the hardness of the ceramic. For example, there has been proposed a method of coating the surface of a ceramic member with diamond or a hard carbon film having high hardness and a small friction coefficient during sliding. However, it has been reported that it is generally difficult to use diamond for a sliding portion because the coating film has a large surface roughness. On the other hand, hard carbon film has characteristics similar to that of diamond, and because a film with extremely small surface roughness can be obtained relatively easily, its application to sliding parts has attracted more attention than diamond. There is.

The hard carbon film, which is also called diamond-like carbon or i-carbon, is an amorphous carbon film having characteristics similar to diamond. Particularly high hardness (Vickers hardness of 5000-800
0), a material having a small friction coefficient when sliding. Although various reports have been made on the method of forming such an amorphous hard carbon film, since the hard carbon film generally has poor adhesion to the substrate, sliding parts coated with this have not been put to practical use. The situation is that there are few things.

Therefore, in order to improve the adhesion to the substrate,
For example, JP-A-63-9543 and JP-A-63-95
As disclosed in Japanese Patent Publication No. 55, etc., attempts have been made to introduce a metal intermediate layer such as silicon, germanium, titanium and chromium. However, in such a method, although the adhesion strength to the metal-based substrate is somewhat improved, the improvement of the adhesion strength to the ceramic-based substrate is insufficient and the amorphous hard Adhesion strength with the carbon film was not sufficient, and a coated ceramic member having excellent sliding characteristics could not be provided.

[0007]

In view of the above-mentioned conventional circumstances, the present invention uses an amorphous hard carbon film having a high hardness and a small friction coefficient as a coating layer, and the intermediate layer between the coating layer and the ceramic substrate is used. An object of the present invention is to provide a coated ceramic member having excellent wear resistance and sliding characteristics by optimizing the material of the layer and the film forming method, and a method for manufacturing the same.

[0008]

In order to achieve the above object, in the coated ceramic member of the present invention, a ceramic base material and an amorphous material having a film thickness of 50 to 5000 Å provided directly on the surface of the ceramic base material. And an amorphous hard carbon film of 1000 Å to 3 μm provided on the silicon intermediate layer.

Further, in the method for producing a coated ceramic member of the present invention, an amorphous silicon intermediate layer having a film thickness of 50 to 5000 Å is formed on the surface of a ceramic substrate by an ion implantation vapor deposition method, and then the silicon intermediate layer is formed. It is characterized in that an amorphous hard carbon film of 1000 Å to 3 μm is formed on the layer by PVD method or plasma CVD method.

[0010]

Although there has been a proposal for a silicon intermediate layer, the crystal structure thereof has not been reported at all, and silicon formed by a PVD method such as a sputtering method or an ion plating method, which is a general film forming method. Since the crystalline structure of the film is crystalline, a crystalline silicon intermediate layer has been used in the past. According to the research conducted by the present inventors, there is a large mismatch such as a lattice constant between the crystalline silicon intermediate layer and the amorphous hard carbon film provided on the crystalline silicon intermediate layer, so that there is a limit in improving the adhesion between the two. Was found to exist.

Therefore, in the present invention, amorphous silicon is adopted as an intermediate layer between the ceramic substrate and the amorphous hard carbon film, and the crystal structure is matched to improve the adhesion between the two. done. Moreover, since the amorphous silicon intermediate layer is formed by the ion implantation vapor deposition method, the adhesion is extremely strong even with the ceramic substrate.

In the ion implantation vapor deposition method, silicon as a material for the intermediate layer is heated and vaporized by an electron beam or the like,
This is a method of accelerating and colliding with the surface of a ceramic base material together with an ion beam of argon or the like generated by an ion source so that the surface is coated simultaneously with the injection into the base material. This method is difficult to increase the irradiation area of ions due to the characteristics of the ion source and has low mass productivity, but has a great advantage that an amorphous silicon intermediate layer having excellent adhesion to a ceramic substrate can be formed. is there.

The thickness of the amorphous silicon intermediate layer is 50 to 5
The reason for setting the range of 000Å is that it is difficult to completely cover the entire surface of the ceramic substrate if the film thickness is less than 50Å, and if it exceeds 5000Å, the film becomes too thick and the surface of the coated ceramic substrate is This is because the hardness decreases.

On the other hand, the amorphous hard carbon film as the outermost layer is formed by a PVD method such as an ordinary vapor deposition method or an ion plating method, or various kinds of plasma utilizing high frequency or microwave. A plasma CVD method is used. Amorphous hard carbon film has poor thermal stability and its crystal structure is likely to change at 400 ° C or higher. Therefore, the method such as hot filament CVD method, which has high film formation temperature, is not suitable, and film formation at low temperature is possible. It is necessary to adopt a simple plasma CVD method or PVD method. The plasma CVD method, which has a high throwing power, is suitable for forming a film on the surface of a substrate having a complicated shape. The PVD method has a slightly poor throwing power, but a flat substrate surface has a better throwing power than the plasma CVD method. Since it is possible to form a film with good productivity, it is preferable to use the film properly according to the shape of the ceramic substrate.

The thickness of the amorphous hard carbon film is 1000Å
The reason for setting it in the range of (0.1 μm) to 3 μm (30000Å) is that the film thickness is too thin when the thickness is less than 1000 Å and the effect of improving wear resistance and sliding resistance due to coating does not appear significantly.
This is because if the thickness exceeds μm, the internal stress of the film becomes large, and film peeling may occur depending on the usage conditions. Also, in terms of productivity, it is not preferable to unnecessarily increase the film thickness.

[0016]

Example 1 Evaporating metallic silicon by an ion implantation vapor deposition method together with an ion beam of argon and accelerating voltage 20
An amorphous silicon intermediate layer having various thicknesses shown in Table 1 below was formed on the surface of the alumina substrate by eV. Next, 13.5
Amorphous hard carbon films of various thicknesses shown in Table 1 were formed on the amorphous silicon intermediate layer at a film forming temperature of 250 ° C. using methane gas as a source gas by a high frequency plasma CVD method of 6 MHz.

Using each of the obtained samples, a sliding test with an alumina ball was carried out by a ball-on-disk method at a sliding speed of 20 m / min, a pressing load of 50 g, and a sliding time of 5 at maximum.
Table 1 shows the results of examining the sliding characteristics of each sample, which was carried out under the condition of 00 hours. Further, a sample of a comparative example having the same structure as above except that a crystalline silicon intermediate layer was used was also tested in the same manner, and the results are also shown in Table 1.

[0018]

TABLE 1 Si intermediate layer hard C film sliding Test results Sample thickness (Å) thickness ([mu] m) Friction coefficient sliding time (hr) 1 * 30 0.05 0.4 22 2 * 50 0.05 0.02 250 3 50 0.1 0.01> 500 4 100 0.2 <0.01> 500 5 300 0.3 <0.01> 500 6 500 0.1 <0.01> 500 7 500 0.5 <0.01> 500 8 500 1.0 <0.01> 500 9 500 2.0 <0.01> 500 10 500 3.0 <0.01 > 500 11 * 500 3.5 <0.01 125 12 2000 1.0 <0.01> 500 13 2500 2.0 <0.01> 500 14 4000 1.5 <0.01> 500 15 4500 3.0 <0.01> 500 16 5000 3.0 <0.01> 500 17 * 5000 3.5 <0.01 210 18 * 5500 3.0 <0.01 240 19 * 3000 2.0 <0.01 120 20 * 4000 1.5 <0.01 140 (Note) The sample marked with * is a comparative example, of which sample 1
9 and 20 are comparative examples in which the Si intermediate layer is crystalline.

[0019]

[Example 2] The silicon intermediate layer formed on the surface of the alumina substrate was made amorphous by the ion implantation vapor deposition method as in Example 1, and the ion plating method or the sputtering method was used as in the conventional method. Used to form crystalline.
The outermost amorphous hard carbon film was formed under ordinary conditions by any one of plasma CVD method, ion plating method and sputtering method.

With respect to each of the obtained samples shown in Table 2, the influence of the crystal structure of the silicon intermediate layer on the adhesion of the amorphous hard carbon film was investigated by an acoustic emission method using a scratch tester, and the critical load was examined. Table 2 shows (N) as adhesion.

[0021]

TABLE 2 Shi Li co down during layer amorphous hard carbon film tight adhesion force sample thickness (Å) crystal structure film formation method thickness (Å) film forming method critical load (N) 21 * 30 amorphous IVD 0.05 IP 10 22 * 30 Amorphous IVD 0.1 IP 15 23 50 Amorphous IVD 0.1 IP 36 24 * 50 Crystalline IP 0.1 IP 16 25 100 Amorphous IVD 0.3 PCVD 42 26 200 Amorphous IVD 1.0 PCVD 45 27 300 Amorphous IVD 0.5 SP 48 28 500 Amorphous IVD 1.5 SP 44 29 500 Amorphous IVD 1.0 SP 45 30 * 1000 Crystalline SP 2.0 PCVD 18 31 1000 Amorphous IVD 2.0 PCVD 48 32 3000 Amorphous IVD 3.0 PCVD 51 33 4000 Amorphous IVD 2.5 PCVD 47 34 4500 Amorphous IVD 3.0 PCVD 53 35 * 4500 Amorphous IVD 3.5 PCVD 26 36 * 5500 Amorphous IVD 3.0 PCVD 28 37 * 5500 Amorphous IVD 4.0 PCVD 19 38 * 5000 Amorphous IVD 5.0 PCVD 8 (Note) * Fee is a comparative example. IVD: Ion implantation evaporation method IP: Ion plating method SP: Sputtering method PCVD: Plasma CVD method

[0022]

According to the present invention, an amorphous hard carbon film having a high hardness and a small friction coefficient is used as a coating layer for a ceramic substrate, and as an intermediate layer between the coating layer and the ceramic substrate. Amorphous silicon is formed by the optimum film thickness or film formation method, so it is suitable for parts that slide at high speed without lubrication in electronic devices and mechanical parts, and has excellent wear resistance and sliding characteristics. A coated ceramic member can be provided.

Claims (2)

[Claims] 1. A ceramic base material, an amorphous silicon intermediate layer having a film thickness of 50 to 5000 Å directly provided on the surface of the ceramic base material, and a film thickness 1000 Å to 3 μm provided on the silicon intermediate layer. And a hard carbon film which is amorphous. 2. An amorphous silicon intermediate layer having a film thickness of 50 to 5000 Å is formed on the surface of a ceramic substrate by an ion implantation vapor deposition method, and then a PVD method or a plasma CVD method is applied on the silicon intermediate layer. A method for producing a coated ceramic member, which comprises forming an amorphous hard carbon film having a film thickness of 1000Å to 3 µm.