JPH0557508A - Vapor-phase synthetic diamond coated cutting tool - Google Patents

Abstract

PURPOSE:To provide a vapor-phase synthetic diamond coated cutting tool that has a long life and is excellent in separation resistance. CONSTITUTION:A vapor-phase synthetic diamond coated cutting tool is made up of a base body and a double diamond coated layer consisting of a first diamond layer whose crystal face formed on the surface of the base body is mainly made up of (100) or (110) and a second diamond layer which is coated on the first diamond layer and whose crystal face is mainly made up of (111).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor phase synthetic diamond coated cutting tool which is excellent in peel resistance.

[0002]

2. Description of the Related Art In recent years, the surfaces of ordinary tungsten carbide (hereinafter referred to as WC) -based cemented carbide substrates containing Co as a binder phase forming component, cermet, silicon nitride, sialon, etc. are coated with diamond by a vapor phase synthesis method. A layered vapor-phase synthetic diamond-coated cutting tool is provided, and the diamond-coated cutting tool is mainly used for cutting Al or Al alloy.

The vapor-phase synthetic diamond coating layer formed on the surface of this diamond-coated cutting tool is mainly composed of (10
It is known that it is composed of 0), (110) and (111) crystal faces, but the above (111) crystal face diamond coating layer has poor adhesion to the substrate and is easily peeled off. Therefore, for example, in Japanese Patent Laid-Open No. 62-107068, a vapor-phase synthetic diamond-coated cutting tool in which a surface of a substrate is coated with a diamond layer having an area of 50% or more of (100) crystal faces or (110) crystal faces Is provided.

[0004]

However, the above (10)
The 0) crystal face diamond and the (110) crystal face diamond have lower hardness than the (111) crystal face diamond, and the (100) crystal face diamond or (1)
10) The vapor-phase synthetic diamond coating layer having a crystal plane diamond of 50% or more has excellent adhesion to the substrate, but has insufficient hardness and therefore wears quickly, thus resulting in insufficient tool life. was there.

[0005]

Therefore, the present inventor has proposed that a vapor-phase synthetic diamond-coated cutting tool in which a diamond layer having the hardest crystal plane of diamond itself (111) is firmly attached to the surface of a substrate is As a result of conducting research based on the prediction that the service life will be even longer, (100) or (11) which has the best adhesion to the surface of the substrate.
0) coating the first diamond layer mainly composed of crystal planes,
Excellent hardness (111) on the first diamond layer
When the second diamond layer mainly composed of crystal planes is coated,
It has been found that the second diamond layer mainly composed of the (111) crystal plane can be firmly adhered to the surface of the substrate, and therefore a diamond-coated cutting tool having a longer tool life than the conventional one can be obtained. Of.

The present invention has been made based on the above findings, and is a first structure in which the substrate and the crystal plane formed on the surface of the substrate are mainly (100) or (110).
A vapor-phase synthetic diamond-coated cutting tool comprising: a double diamond coating layer comprising a diamond layer and a second diamond layer having a crystal plane coated on the first diamond layer and having (111) as a main component. It has characteristics.

In the present invention, the first diamond layer whose crystal plane is mainly composed of (100) is a diamond layer in which (100) crystal plane diamond has the strongest peak in X-ray diffraction, and the crystal plane is (110). The first diamond layer mainly composed of (110) is a diamond layer in which a (110) crystal plane diamond has the strongest peak in X-ray diffraction, and the second diamond layer mainly composed of (111) crystal planes is The (111) crystal plane diamond is a diamond layer having the strongest peak in X-ray diffraction.

The diamond layer is formed by the known CVD and P
Although it can be manufactured by the VD method, it is preferably formed by the CVD method, and a mixed gas of a normal hydrocarbon gas and hydrogen gas is introduced into a reaction vessel to form a hot filament,
A diamond layer can be formed on the substrate by exciting the mixed gas with high frequency, microwave, or the like.
The second diamond coating layer whose crystal plane is mainly (111) can be formed by maintaining the heating temperature at 850 ° C. or lower, while the first diamond whose crystal plane is mainly (110). The coating layer has a heating temperature of 950 ° C.
It can be formed by holding at 1050 ° C, and the first diamond coating layer whose crystal plane is mainly (100) has a heating temperature higher than 1050 ° C to 1200 ° C.
It can be formed by holding.

The total layer thickness of the first diamond coating layer and the second diamond coating layer must be in the range of 2 to 100 μm, preferably 5 to 50 μm. Further, the above-mentioned substrate contains Co: 4 to 20% by weight and, if necessary, further contains 4a and 5 of the periodic table excluding W.
Carbides of a and 6a group metals, or a solid solution of these carbides and WC: 0.5 to 30% by weight, and the balance is preferably a WC-based cemented carbide having a composition of WC and inevitable impurities. However, the material is not limited to this, and cermet, silicon nitride, sialon, or the like can be used as the substrate.

[0010]

EXAMPLES Next, the vapor phase synthetic diamond-coated cutting tool of the present invention will be specifically described based on examples.

Example 1 As raw material powders, WC powder, TiC powder, TaC powder, (Ti, W) C powder and Co powder each having an average particle diameter of 0.8 μm were prepared, and these raw material powders were TiC powder: 4
% By weight, TaC powder: 1% by weight, (Ti, W) C powder:
1% by weight, balance: WC powder was blended, the blended powder was wet mixed in a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 1.5 ton / cm ² , and this pressure was applied. The powder was sintered under normal conditions to produce a sintered body having a composition substantially the same as the above composition.

The surface of this sintered body was ground, the shape thereof was molded into a chip of ISO standard SPGN120308 (K type), and this chip was placed in a quartz reaction vessel equipped with a metal W filament, and the above quartz was used. By keeping the inside of the reaction vessel under the following conditions, the average layer thickness: 3 μm (100)
Forming a first diamond coating layer mainly composed of crystal planes,
Then, on the first diamond coating layer mainly composed of the (100) crystal plane, the average layer thickness: 2 μm (1
11) The diamond-coated chip 1 of the present invention was produced by forming the second diamond-coated layer mainly composed of crystal planes.

Example 2 Furthermore, the above chip prepared in Example 1 was placed in a quartz reaction vessel equipped with a metal W filament, and the inside of the quartz reaction vessel was maintained under the following conditions to obtain an average layer thickness. :
A first diamond coating layer mainly composed of (110) crystal planes of 3 μm was formed, and then an average layer thickness was formed on the first diamond coating layer mainly composed of (110) crystal planes under the same conditions as in Example 1. A diamond-coated chip 2 of the present invention was produced by forming a second diamond-coated layer having a (111) crystal plane of 2 μm as a main component.

Conditions for forming diamond layer mainly composed of (100) crystal plane: Atmospheric pressure: 30 Torr, substrate temperature: 1100 ° C., reaction gas: methane gas concentration: mixed gas consisting of methane gas and hydrogen gas at 1% by volume, gas flow rate: 1 liter / second,

Conditions for forming a diamond layer mainly composed of a (110) crystal plane: atmosphere pressure: 30 Torr, substrate temperature: 1050 ° C., reaction gas: methane gas concentration: mixed gas of methane gas and hydrogen gas of 1% by volume, gas flow rate: 1 liter / second,

Conditions for forming diamond layer mainly composed of (111) crystal plane: Atmospheric pressure: 30 Torr, substrate temperature: 800 ° C., reaction gas: methane gas concentration: mixed gas consisting of methane gas and hydrogen gas of 1% by volume, gas flow rate: 1 liter / second,

The crystal planes of the first diamond coating layer and the second diamond coating layer formed on the diamond-coated chip 1 of the present invention chemically change the substrate of the diamond-coated chip 1 of the present invention or the diamond-coated chip 2 of the present invention. The double diamond coating layer composed of the first diamond coating layer and the second diamond coating layer formed on the surface by melting was taken out, and the front surface and the back surface were identified by X-ray diffraction.

Comparative Example 1 The chip prepared in Example 1 was placed in a quartz reaction vessel equipped with a metal W filament, and the average layer thickness was 5 μm under the same conditions as those for forming the first diamond coating layer in Example 1. (1
00) A first diamond coating layer having a crystal plane as a main component was formed to prepare a comparative diamond-coated chip 1.

Comparative Example 2 The chip prepared in Example 1 was placed in a quartz reaction vessel equipped with a metal W filament, and the inside of the quartz reaction vessel under the conditions shown in Example 2 had an average layer thickness of 5 μm. (110)
A comparative diamond-coated chip 2 was produced by forming a diamond-coated layer mainly composed of crystal planes.

Comparative Example 3 The chip prepared in Example 1 was placed in a quartz reaction vessel equipped with a metal W filament, and the average layer thickness was 5 μm under the same conditions as those for forming the first diamond coating layer in Example 1. (1
11) A diamond coating layer mainly composed of crystal planes was formed, and a comparative diamond coating chip 3 was produced.

Comparative Example 4 The chip prepared in Example 1 was placed in a quartz reaction vessel equipped with a metal W filament, and the average layer thickness was 3 μm under the same conditions as those for forming the first diamond coating layer in Example 1. (1
(00) A first diamond coating layer mainly composed of crystal planes was formed, and then an average layer thickness of 2 μm was formed on the first diamond coating layer mainly composed of (100) crystal planes under the same conditions as in Comparative Example 2. A comparative diamond-coated chip 4 was prepared by forming a second diamond-coated layer mainly composed of a (110) crystal plane.

These diamond-coated chips 1 to 1 of the present invention
Table 1 summarizes the configurations of the diamond coating layers of 2 and comparative diamond coated chips 1 to 4.

[0023]

[Table 1]

These diamond-coated chips 1 to 1 of the present invention
2 and comparative diamond coated chips 1 to 4, work material: Al-18% Si, cutting speed V: 300 m / min, depth d: 1 mm, feed Sz: 0.2 mm / rev, wet condition A continuous cutting test was conducted to measure the continuous cutting time until the diamond coating layer of the chip disappeared, and the measurement results are shown in Table 2.

Further, 10 pieces of each of the diamond-coated chips 1 and 2 of the present invention and 10 pieces of the comparative diamond-coated chips 1 to 4 were used, and a work material: Al-18% Si, a cutting speed V: 200 m / min, and a cut d: 1 mm. Feed Sz: 0.3 mm / tooth, a wet milling cutting test was performed, and after 30 minutes, the number of chips from which the diamond coating layer of the chips had peeled off was measured. The measurement results are also shown in Table 2. ..

[0026]

[Table 2]

[0027]

[Effects of the Invention] The diamond-coated chip 1 to 1 of the present invention described above.
2 and the comparative diamond-coated chips 1 to 4 all have a diamond coating layer thickness of 5 μm, but the diamond-coated chips 1 and 2 of the present invention have a diamond coating layer that is continuously cut more than the comparative diamond-coated chips 1 to 4. It can be seen that the diamond coating layer does not peel off even after milling for 30 minutes, and the service life is long. Therefore, by using the vapor phase synthetic diamond-coated cutting tool of the present invention, the cost can be reduced and the industrially excellent effect can be obtained.

Claims (2)

[Claims] 1. A substrate, a first diamond layer whose crystal face formed on the surface of the substrate is (100) as a main component, and a crystal face coated on the first diamond layer is (111) as a main component. And a double diamond coating layer composed of a second diamond layer and a cutting tool coated with vapor phase synthetic diamond. 2. A substrate, a first diamond layer whose crystal plane formed on the surface of the substrate is mainly (110), and a crystal plane coated on the first diamond layer is mainly (111). And a double diamond coating layer composed of a second diamond layer and a cutting tool coated with vapor phase synthetic diamond.