JPH0360901A - Surface covering cutting tool member having hard covering layer excellent in adhesion - Google Patents

Abstract

PURPOSE:To enhance the adhesion by forming a hard covering layer consisting of the artificial diamond thin layer of 0.1-1mum mean layer thickness formed by a vapor phase synthesis and a similarly formed alternate lamination layers consisting of more than two layers respectively of an amorphous carbon layers in 0.1-1mum mean layer thickness, more than four layers in total, on the surface of a tungsten carbide base sintered hard alloy base body. CONSTITUTION:A hard covering layer consisting of the artificial diamond thin layer in 0.1-1mum mean layer thickness formed by a vapor phase synthesis and the similarly formed alternate lamination layers more than tow layers respectively of an amorphous carbon thin layer, more than four layers in total, is formed on the surface of a WC base sintered hard alloy base body. This covered layer is not peeled off even under the high temperature heating conditions at the time of cutting, thus the adhesion thereof becomes excellent and the wear resistance can be exhibited over a long period of time.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a surface-coated cutting tool member that exhibits excellent wear resistance over a long period of time without causing peeling of the hard coating layer during cutting. It is something.

[Conventional technology]

Conventionally, in general, for cutting AI and Ag alloys, Cu and Cu alloys, etc., tungsten carbide (hereinafter referred to as WC) was coated on the surface of a cemented carbide substrate, for example, in JP-A-58-9.
Using a vapor phase synthesis method such as a hot filament method as described in Japanese Patent Publication No. 1100 or a microwave non-polar discharge method as described in Japanese Patent Application Laid-Open No. 1104949/1980, an artificial diamond coating layer is A surface-coated cutting tool member formed with an average layer thickness of 7 μm is used.

[Problem to be solved by the invention]

However, in recent years, with the increasing speed and labor saving of cutting, there has been a tendency to cut under harsh conditions such as high speed cutting and heavy cutting such as high feed and high depth of cut. The coated cutting tool member is composed of WC
C Cemented Carbide Base Thermal Expansion Coefficient is 4.0 to 6.5xlO'
/°C, whereas that of the artificial diamond coating layer is 1.18X10'/'C, so there is a large difference in coefficient of thermal expansion between the two, so it is particularly difficult to operate under the above harsh conditions. When cutting at the bottom, the artificial diamond coating layer tends to peel off due to this large difference in thermal expansion coefficient, and the current state of the art is that it reaches the end of its service life in a relatively short period of time.

[Means to solve the problem]

Therefore, from the above-mentioned viewpoint, the present inventors focused on the above-mentioned conventional surface-coated cutting tool members, and as a result of conducting research to prevent the peeling of the artificial diamond coating layer constituting the tool members, they found that When forming an artificial diamond layer by the phase synthesis method, a diamond layer or an amorphous carbon layer can be formed arbitrarily on the substrate surface by adjusting the reaction mixture gas composition, the atmospheric pressure in the reaction vessel, etc. , the hard coating layer formed on the surface of the WCC cemented carbide substrate is made up of two layers each of an artificial diamond thin layer with an average layer thickness of 0.1 to 1 μs and an amorphous carbon thin layer with an average thickness of <0.1 to 1 μs. As described above, when a total of four or more layers are alternately laminated, the hard coating layer of this alternately laminated structure is composed of a relatively large amorphous carbon thin film having a thermal expansion coefficient of, for example, 5.4X 10'/℃. As a result of this action, it has a thermal expansion coefficient close to that of WCC cemented carbide, so it does not peel off even under high temperature heating conditions during cutting, has excellent adhesion, and has excellent durability. They found that it exhibits wear resistance over a long period of time.

This invention was made based on the above-mentioned knowledge, and is the same as an artificial diamond thin layer with an average layer thickness of 0.1 to 1 μm formed by vapor phase synthesis on the surface of a WCC cemented carbide substrate. A surface-coated cutting tool member having a hard coating layer with excellent adhesion formed by forming a hard coating layer consisting of two or more alternately laminated amorphous carbon thin layers of 1 to IJEo, and a total of four or more layers. It has characteristics.

In the surface-coated cutting tool member of the present invention, the average layer thickness of the artificial diamond thin layer and the amorphous carbon thin layer is set to 0.1 to 1 part, respectively, because the average layer thickness of the former is 0.
If the average layer thickness of the latter is less than 0.1, the desired excellent wear resistance cannot be ensured. If it is less than bs, the effect of improving the coefficient of thermal expansion of the hard coating layer is insufficient, and the effect of improving the coefficient of thermal expansion is also affected by the number of alternate laminations of these layers, and it is not reliable unless each layer is 2 or more layers, and 4 or more layers in total. On the other hand, when the average layer thickness exceeds 1 μm, the relatively small coefficient of thermal expansion of the artificial diamond thin layer begins to affect the hard coating layer. This is because delamination tends to occur in the hard coating layer, and the abrasion resistance of the hard coating layer decreases in the case of an amorphous carbon thin film.

〔Example〕

Next, the surface-coated cutting tool member of the present invention will be specifically explained using examples.

First, the WCC cemented carbide base material is WC-1 in weight%.
Composition of %TaC-6%Co, thermal expansion coefficient of 4.6 x 10'/''C, and ISO standard SP GN 120
Prepare a throw-away tip with a 308 shape,
Using the hot filament method described in JP-A-58-91100, the surface of these chips was coated with a reaction vessel having an outer diameter of 120 mm.
mμm quartz tube, reaction mixture gas composition: volume ratio, CH
4/H2-5 to 15/1000, Heating temperature of thermionic emitting material (metal W filament):
Table 1 shows the following conditions: 2000°C, atmospheric pressure in the reaction vessel = 25 to 60 torr, distance between the thermionic emitting material and chip surface: 35 torr, chip surface heating temperature by the thermionic emitting material: 850°C. Surface-coated cutting tool members of the present invention (hereinafter referred to as the coated cutting tips of the present invention) 1 to 5 by forming a hard coating layer consisting of an artificial diamond thin layer and an amorphous carbon thin layer with the indicated layer thickness and number of layers, and A comparative surface-coated cutting tool member (with a hard coating layer structure outside the scope of the present invention)
Conventional surface-coated cutting tool members (hereinafter referred to as conventional coated cutting tips) were manufactured, respectively, with a single layer of artificial diamond formed without forming an amorphous carbon thin layer (hereinafter referred to as comparative coated cutting tips). ) was manufactured.

In addition, when forming the hard coating layer of the coated cutting chips 1 to 5 of the present invention and the comparative coated cutting chips 1 to 6, artificial The layer formation was changed from a diamond thin layer to an amorphous carbon thin layer and vice versa.

Next, for the various coated cutting chips obtained as a result, the thermal expansion coefficient of the hard coating layer was measured.
000m/Ifin.

A dry high-speed continuous cutting test was conducted on Ag alloy under the conditions of depth of cut = 1.5 mm feed, 0.2111 m/rev, and the cutting time until the flank wear width of the cutting edge reached 0.2 mm was determined by δp1. did. The results of these measurements are shown in Table 1.

〔Effect of the invention〕

From the results shown in Table 1, it can be seen that the present invention/light coated cutting tip 1
-5, the hard coating layer constituting this has a thermal expansion coefficient close to 4.6X 10'/℃ that of the WCC cemented carbide base, so there is no peeling of the hard coating layer, and the artificial diamond thin layer Comparative coated cutting tip 1 exhibits excellent wear resistance over a long period of time due to its high hardness, but the thickness of the artificial diamond thin layer is outside the scope of the present invention and is thin. Comparative coated cutting tip 2 with a single layer thickness outside the scope of the present invention and comparative coated cutting tip 3 with a thick amorphous carbon layer thickness outside the scope of the present invention exhibit sufficient wear resistance. Comparative coated cutting chip 4, in which the layer thickness of the amorphous carbon thin film is thin, which is out of the range of the present invention; Comparative coated cutting chip 4, in which the number of amorphous carbon thin layers is 1 layer, which is out of the range of the present invention. 5, a comparative coated cutting tip 6 in which the thin layer of artificial diamond is thicker than the scope of the present invention, and a conventional coated cutting tip in which the hard coating layer is made of a single layer of artificial diamond, all of which have peeling in the hard coating layer. It is clear that this occurs and that it reaches the end of its service life in a short period of time.

As described above, the surface-coated cutting tool member of the present invention has a WCC cemented carbide substrate with a thermal expansion coefficient that is made close to that of the thin amorphous carbon layer and the artificial diamond thin layer constituting the hard coating layer by alternately stacking the thin layer and the thin layer of artificial diamond. , and the presence of the artificial diamond thin layer between the amorphous carbon thin layers, ensuring excellent wear resistance, and the hard coating layer exhibits excellent cutting performance over a long period of time without peeling.

Out 廓 Man 2. Mitsubishi Metals Co., Ltd. teenager Reason Man ω Field sum husband 1 other person

Claims (1)

[Claims] (1) An artificial diamond thin layer with an average layer thickness of 0.1 to 1 μm formed by vapor phase synthesis on the surface of a tungsten carbide-based cemented carbide substrate, and an average layer thickness of 0.1 to 1 μm as well.
A surface-coated cutting tool member having a hard coating layer with excellent adhesion formed by forming a hard coating layer consisting of two or more alternately laminated amorphous carbon thin layers, each consisting of four or more layers in total.