JP3189353B2 - Coated ceramic member and method of manufacturing the same - Google Patents

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 producing the same.

[0002]

2. Description of the Related Art Ceramics have excellent properties in terms of wear resistance, corrosion resistance, heat resistance, and the like, which cannot be achieved with metals at all. Is being advanced.

[0003] In particular, recently, attempts have been made to use ceramic for parts that slide at high speed in an unlubricated state in electronic equipment and mechanical parts. However, since ceramics have extremely high hardness, there is a disadvantage that a wrong material may damage or wear the mating material if used improperly. Further, since the friction coefficient (μ) of the ceramic itself is very high, there is a disadvantage that frictional heat is generated and the temperature of the sliding portion rises, and the friction coefficient of the ceramic member further increases due to the temperature rise.

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

[0005] The hard carbon film, 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 to 800)
0), a material having a small friction coefficient during sliding. Various reports have been made on the method of forming such an amorphous hard carbon film. However, since a hard carbon film generally has poor adhesion to a substrate, sliding parts coated with the hard carbon film have been put to practical use. It is the present condition that there are few things.

Therefore, in order to improve the adhesion to the substrate,
For example, JP-A-63-9543 and JP-A-63-9563
As disclosed in Japanese Patent Publication No. 55-55 and the like, 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 is somewhat improved with respect to a metal-based substrate, the improvement in the adhesion strength is not sufficiently improved with respect to a ceramic-based substrate, and an amorphous hard material is used. The adhesion strength to the carbon film was not sufficient, and a coated ceramic member having excellent sliding characteristics could not be provided.

[0007]

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

[0008]

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

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

[0010]

Although there has been a proposal for a silicon intermediate layer, no report has been made on its crystal structure, and silicon formed by a PVD method such as a general film forming method such as a sputtering method or an ion plating method. Since the crystal structure of the film is crystalline, a crystalline silicon intermediate layer has been conventionally used. According to the study of 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 thereon, and therefore, the improvement in the adhesion between the two is limited. Was found to exist.

Therefore, in the present invention, amorphous silicon is employed as an intermediate layer between the ceramic base material and the amorphous hard carbon film, and the adhesion between the two is improved by matching the crystal structures. done. Further, 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 deposition method, silicon as a material of 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 substrate together with an ion beam of argon or the like generated by an ion source to coat the surface simultaneously with injection into the substrate. This method is difficult to increase the ion irradiation area 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 extremely good adhesion to a ceramic substrate can be formed. is there.

The thickness of the amorphous silicon intermediate layer is 50 to 5
If the thickness is less than 50 °, it is difficult to completely cover the entire surface of the ceramic substrate. If the thickness exceeds 5000 °, the thickness of the ceramic substrate becomes too large, and the surface of the coated ceramic substrate becomes too thick. This is because the hardness decreases.

On the other hand, an amorphous hard carbon film as an outermost layer is formed by a PVD method such as an ordinary vapor deposition method or an ion plating method, or various types using a high frequency or a microwave to excite plasma. The plasma CVD method is used. Amorphous hard carbon films have poor thermal stability and their crystal structure tends to change above 400 ° C. Therefore, methods such as the hot filament CVD method, which has a high film forming temperature, are inappropriate, and films can be formed at low temperatures. It is necessary to adopt a suitable plasma CVD method or PVD method. In addition, the plasma CVD method with high throwing power is suitable for film formation on a substrate surface having a complicated shape, and the PVD method has slightly poor throwing power, but is more suitable for a flat substrate surface than the plasma CVD method. Since it is possible to form a film with good productivity, it is preferable to selectively use them according to the shape of the ceramic substrate.

The thickness of the amorphous hard carbon film is 1000
(0.1 μm) to 3 μm (30000 °), the reason is that if the thickness is less than 1000 °, the coating film is too thin to significantly improve the abrasion resistance and sliding resistance, and the effect is not significant.
If the thickness exceeds μm, the internal stress of the film increases, and film peeling occurs depending on the use conditions. Also, from the viewpoint of productivity, it is not preferable to increase the thickness unnecessarily.

[0016]

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

Using each of the obtained samples, a sliding test with an alumina ball was performed 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 up to 5 minutes.
Table 1 shows the results obtained by examining the sliding characteristics of each sample under the conditions of 00 hours. Also, a sample of a comparative example having the same configuration as described above except that the crystalline silicon intermediate layer was used was tested in the same manner, and the results are 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.
9 and 20 are comparative examples in which the Si intermediate layer is crystalline.

[0019]

Example 2 A silicon intermediate layer formed on the surface of an alumina substrate was formed amorphous by ion implantation and vapor deposition as in Example 1, and ion plating or sputtering was performed as in the prior art. And formed crystalline.
The outermost amorphous hard carbon film was formed under normal conditions by any one of a plasma CVD method, an ion plating method and a sputtering method.

For each of the 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 measured. (N) is shown in Table 2 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 deposition 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 on a ceramic substrate, and an intermediate layer between the coating layer and the ceramic substrate is used. Since amorphous silicon is formed by the optimal film thickness or film forming method, it has excellent abrasion resistance and sliding characteristics suitable for high-speed sliding of electronic devices and mechanical parts in a non-lubricated state. A coated ceramic member can be provided.

Claims (2)

(57) [Claims] 1. A ceramic substrate, an amorphous silicon intermediate layer having a thickness of 50 to 5000 ° provided directly on the surface of the ceramic substrate, and a film thickness of 1000 to 3 μm provided on the silicon intermediate layer. A coated ceramic member comprising an amorphous hard carbon film of 2. An amorphous silicon intermediate layer having a film thickness of 50 to 5000 ° is formed on the surface of a ceramic substrate by an ion implantation vapor deposition method, and is then formed on the silicon intermediate layer by a PVD method or a plasma CVD method. A method for producing a coated ceramic member, comprising forming an amorphous hard carbon film having a thickness of 1000 to 3 [mu] m.