JPH0288782A - Production of diamond-coated member - Google Patents

Abstract

PURPOSE:To easily produce the title diamond-coated member having excellent adhesion by selectively vapor-etching a binder of Co, etc., on the surface of a cermet substrate, and thereby forming a diamond film on the substrate surface. CONSTITUTION:The cermet substrate 3 with the surface coated with a binder consisting of Co and/or Ni is set in a reaction vessel 2, the vessel 2 is depressurized by a vacuum pump 5, and a gaseous etchant contg. at least one kind among carbon monoxide, water, and gaseous hydrogen halides is introduced from an inlet pipe 1. The substrate 3 is then heated to a specified temp. by a heater 7, a plasma is produced from a microwave power source 4 through a waveguide 6, and the surface of the substrate 3 is etched. When the etching is finished, a diamond film forming gas is supplied to the reaction vessel 2 from the inlet pipe 1 to produce plasma, and a diamond film is formed on the surface of the substrate 3. By this method, a diamond-coated member having excellent adhesion is easily obtained in a short time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a diamond-coated companion material and a tool using the material, and particularly to a method for easily forming a diamond film with excellent layer density. This invention relates to a pretreatment method suitable for.

[Prior art] We-Co or the like was used as the carbide tool material. The surface of cermet or this cemented carbide is further coated with TiC or Tin.

Hard materials coated with ALROs and the like are used.

However, as cutting efficiency improves, there is an increasing demand for coated members with higher hardness from the viewpoint of tool wear resistance and tool life extension.

Diamond is an optimal material due to its high hardness and excellent wear resistance. If it can be coated on a cermet body, cutting efficiency can be significantly improved. But diamonds. When performing vapor phase synthesis on a cermet substrate. Co and Ni constituting the cermet substrate act catalytically to speed up the decomposition of carbon source gases such as methane, making it easier for graphite to precipitate.

For this reason, it is difficult to form a diamond film directly on one piece, and even if coating is possible, if it is used in high temperature conditions due to frictional heat during cutting, c.

Since Cl and Ml catalytically promote the transition reaction of diamond to graphite, the Co-lli contact surface becomes graphite, reducing adhesion and causing film peeling. Therefore, it contains Co and 11. Cermet 1
Direct coating on the body is not preferred.

A conventional method for improving adhesion by preventing the influence of Co and 11 is to use T10° TiN, A between the substrate and the diamond film as described in Jikai No. 1@5B-126972.
Co by coating a diamond film through an intermediate layer such as 40B or AtN, or by pretreatment such as pickling treatment as described in JP-A No. 61-52363.
There is a method of removing lli and coating with a diamond film.

[Problems to be Solved by the Invention] In the above-mentioned conventional interlayer film forming method,... Expensive equipment is required to form an intermediate film such as Tie, Tin, A/, O, etc. on a cermet substrate. Furthermore, since these intermediate films are formed by sputtering or the like and have good surface smoothness, adhesion is not sufficient.

The pickling treatment method has problems with complicated processes such as water washing and drying, waste liquid treatment, etc., and it also uses other materials other than Co and Ni. Since even We, which is the main component of the cermet substrate, is etched, the surface of the substrate becomes rough and the smoothness of the diamond film after coating becomes poor.

As mentioned above, the conventional technology does not give sufficient consideration to the smoothness of diamond and the economic efficiency of the process, and there are problems with tool life, finished surface accuracy, cost, etc.

The object of the present invention is to remove diamond films that have been crushed due to their adhesion. It is an object of the present invention to provide a method for forming a cermet body by an economically simple process, and a tool using the same.

[Means to solve the problem]

The above purpose is. This is achieved by selectively vapor phase etching a binder such as Co and/or Ni present on the surface of a cermet substrate, and then forming a diamond film on the surface of the substrate.

That is, the present invention... The present invention relates to a method for producing a diamond-coated member, which comprises selectively etching a binder such as Co and/or Ni present on the surface of a cermet substrate in a vapor phase, and then forming a diamond film on the surface of the substrate.

In the above manufacturing method, a gas containing at least one of carbon monoxide, water, or hydrogen halide gas is used as the gas for vapor phase etching.

Further, the gas phase etching gas and the gas for forming a diamond film on the surface of the single body may be the same type of gas, such as a mixed gas of carbon oxide and hydrogen. and,. The process of selective vapor phase etching of Co and/or Ni on the surface of a cermet substrate and the process of forming a diamond film on the surface of the substrate can be performed using the same apparatus. Existing equipment for vapor phase etching or diamond film formation can be used as the equipment.

Furthermore, the diamond-coated member obtained by the production method of the present invention has excellent adhesion and is suitable for making a diamond-coated tool.

An example of the present invention will be described below with reference to FIG.

Etching gas is supplied from a gas introduction pipe 1 to a reaction vessel 2 whose pressure is reduced by a vacuum pump 5. A substrate 3 is installed in the reaction vessel 2. After the substrate 3tI'i is heated to a predetermined temperature by the heater 7, plasma is generated from the microwave power source 4 through the waveguide 6, and the surface of the substrate 3 is etched. After etching for a predetermined period of time, a diamond film forming gas is supplied from the gas introduction pipe 1 to the reaction vessel 2. A diamond film or a diamond-like carbon film is formed on the surface of the substrate 30 by generating plasma. The diamond film is
It is formed by decomposing hydrogen and a hydrocarbon gas such as carbon monoxide, hydrogen and methane, or hydrogen and an oxygen-containing organic compound such as alcohol or acetone using plasma or a hot filament.

Microwaves, high frequencies, and DC power sources can be used to form plasma.

[Effect]

Carbon monoxide, water or hydrogen halide is excited and activated by plasma etc. Easily reactive C on the surface of the cermet substrate
Co04. reacts with Co04.
1ai04, Co(OH)1*Ni(OI
I),, in the case of carbon monoxide, Co (Co),, 1l
i(aO), etc., and are presumably etched. Especially carbon monoxide, Co and Ni in the case of water
Because of its high reactivity with the substrate, it is possible to selectively remove Co and Lai from the substrate surface, where diamond nuclei are difficult to form, and at the same time, it is possible to create minute scratches on the surface, resulting in strong adhesion to the substrate. A diamond film can be formed.

[Implementation row]

Hereinafter, the present invention will be explained in more detail and specifically using examples, but the present invention is not limited to these examples.

[Example 1] Using the plasma reactor shown in Fig. 1, T10 (20%
), Co (6%), Ni (8%), and We (66%). Co and l on the surface of the cermet substrate
ai was subjected to plasma etching treatment under the conditions shown below.

Etching gas: Co (2701%) +H, (9
8701%) Pressure: 4 0
Torr microwave output = 50 OW Substrate temperature = 6Co°C Processing time = 10 minutes The substrate surface that was not subjected to plasma etching treatment and the surface of the etched substrate were subjected to S-MB (secondary ion mass spectrometry).
Co and lli were analyzed. Co and Ni1 were detected from the substrate that was not etched, but almost no Co and Ni were detected from the etched substrate, confirming that Co and Ni were removed. A diamond film was formed on this etched substrate under the following conditions.

Reaction gas: OH4 (1vo1%) 10H, (99
vo1%) Pressure: 4 0
Torr microwave emission crab I KW Substrate temperature: 28 Co° C. Reaction time: 5 h The film formed on the substrate had a thickness of 2 μm and was identified as a diamond film (by X-ray diffraction and Raman spectroscopy). The adhesion between the diamond film and the substrate was measured (by scratching method) and was found to be 2-1 to 2.7 kl! A value of /■3 was obtained. This value is an adhesion force sufficient to withstand practical use as a coated tool film.

As a comparative example, a film was formed under the above conditions using a substrate that was not etched. When the film was identified by X-ray diffraction, peaks based on diamond and graphite were detected. The results of measuring the adhesion to the substrate were IIL1~(1
2, it was 97 mt., a value that could not be put to practical use.

[Example 2] Using the same substrate and equipment as in Example 1,
)+H,O (5 vol%) etching gas was used to perform etching treatment under the conditions shown below.

Pressure: 40 Torr Microwave output crab 50 mouths W Substrate temperature = 6Co°C Processing time = 10 minutes After the etching process, the substrate surface was analyzed by 8 mm M8.
It was confirmed that Co and Ni were removed from the substrate surface. A diamond film having a thickness of approximately 2 μm was formed using the substrate under the same conditions as in Example 1. The results of measuring the adhesion strength with one body by the scratch method showed an excellent adhesion strength of 2-3 to 2.8 kp/■2.

[Example 3] Using the same substrate and equipment as in Example 1, Ar (90vo1%)
Etching treatment was carried out under the same conditions as in Example 2 using an etching gas of ) + HOl (10vol%).

The surface of the substrate was analyzed using an 8-mm M8, and it was confirmed that Co and Ni had been removed from the surface of the substrate. A diamond film having a thickness of approximately 2 μm was formed using the substrate under the same conditions as in Example 1. The measurement result of the adhesion of the film to the substrate is 1.5 to 2.
．． It showed a value of 2 ky/■2.

[Example 4] The same reaction apparatus as in Example 1 was used, using a cemented carbide of WO (94%) -Co (6%) as the substrate and using a slow aqua tip for cutting tools of 80 standard 8PGM 422. Etching treatment was performed using a mixed gas of , 6, co and . Continued C0 (5vo1%) after etching treatment
A diamond film having a thickness of 5 μm was coated using a mixed gas of -H, (95 vol %) under the conditions shown below.

Micro liquid extraction crab I KW Pressure: 40 Torr Substrate temperature: 28 Co°C Reaction time: 1 h Using the coated substrate, a cutting test was conducted under the following conditions.

Wave cutting material: Mut-11% S1 alloy Peripheral speed: 5Com/min Depth of cut: 1. As a result of the CL 5 ml ray cutting test, no peeling of the film was observed even after a cutting time of 1 Co minute, and a diamond coated tool with excellent adhesion was obtained.

[Example 5 and Comparative Example] For the purpose of comparison with the normal pickling method, we shown in actual m1M4
A comparison with the Co plasma treatment according to the present invention was made using -6 wt % Co cutting tips. Table 1 shows the etching conditions for both.

Table 1 The Co concentration near the surface of both etched substrates was 8.
FIG. 2 shows the results of analysis using M8 (secondary ion mass spectrometry). That is, FIG. 2 is a graph showing these results in terms of the relationship between sputtering time (win1 horizontal axis) and □o +2 intensity (arbitrary units, vertical axis). This m2
According to the figure, it was confirmed that Co 2 near the substrate surface can be selectively reduced by the etching method according to the present invention, compared to the pickling method.

A diamond film was formed on both chips using the apparatus shown in Fig. m1, and a cutting test was conducted.

Film formation conditions are Reaction gas: H, -2I C) I.

A diamond film with a film thickness of 6 μm was formed under the conditions of pressure: 40 Torr, microwave output, and reaction time: 5 hours, and performance evaluation was performed by an aluminum cutting test under the following conditions.

Work material: Mu A-13%81 alloy Peripheral speed: 5Com/min Depth of cut: t
〇- Feed: α5 M/rev As a result, the life of the cutting tip etched using the normal pickling method was 50 minutes, whereas the cutting tip treated with the etching process of the present invention lasted for 90 minutes. No peeling of the membrane occurred and the condition was completely normal. It has become clear that according to the present invention, a diamond coated tool with excellent adhesion can be obtained.

Further, the etching method according to the present invention has the advantage that the etching time can be reduced to 1/10 or less compared to the pickling method, and the entire manufacturing process can be performed as a dry process.

[Effects of the Invention] According to the present invention. Co present on the surface of the cermet substrate
Since a bonding agent such as or Ml can be etched in a gas phase using plasma or the like, a diamond-coated member with adhesion of mA can be easily manufactured in a single time. Furthermore, it is possible to perform the etching process and the diamond film formation in the same apparatus using the same reaction gas or by changing the reaction gas composition, thereby simplifying the process.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a graph showing the etching state according to the present invention and the pickling method. DESCRIPTION OF SYMBOLS 1...Reaction gas, 2...Reaction container, 3...1 unit, 4...Microwave power source, 5...Vacuum pump, 6...Waveguide, 7. Heater patent application Between Hitachi, Ltd. Representative of Babcock-Hitachi Co., Ltd. Person Mikaii Nakamoto
Akira Ue (Suichi Makichik) η 碌ωya 2o○

Claims (6)

[Claims] 1. Co and/or Ni present on the surface of the cermet substrate
1. A method for producing a diamond-coated member, which comprises selectively etching a binder consisting of the following in a vapor phase, and then forming a diamond film on the surface of the substrate. 2. 2. The method for producing a diamond coated member according to claim 1, wherein a gas containing at least one of carbon monoxide, water, and hydrogen halide gas is used as the gas for the vapor phase etching. 3. 3. The method of manufacturing a diamond coated member according to claim 1, wherein the gas phase etching gas and the gas for forming a diamond film on the surface of the substrate are the same type of gas. 4. A method for producing a diamond coated member using a mixed gas of carbon monoxide and hydrogen as the gas according to claim 3. 5. The diamond coating according to any one of claims 1 to 4, wherein the step of selective vapor phase etching of Co and/or Ni on the surface of a cermet substrate and the step of forming a diamond film on the surface of the substrate are performed in the same apparatus. Manufacturing method of parts. 6. A diamond coating tool using a diamond coating member obtained by the manufacturing method according to any one of claims 1 to 5.