JP3109306B2 - Surface-coated cermet cutting tool with improved wear resistance of hard coating layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool made of a surface-coated cermet in which the wear resistance of a hard coating layer is further improved as compared with the conventional one.

[0002]

2. Description of the Related Art Conventionally, tungsten carbide (hereinafter, referred to as "tungsten carbide")
WC) based cemented carbide and titanium carbonitride (hereinafter TiC)
N) on a surface of a cermet substrate such as a base cermet or the like by a chemical vapor deposition method, Ti carbides, nitrides, carbonitrides, carbonitrides, and aluminum oxides (hereinafter, TiC, TiN, TiCN, TiCN, respectively). TiCNO,
And Al ₂ O ₃ ).
Hard coating layer consisting of multiple layers of at least 0.5 to 20 μm
It is also known that a surface-coated cermet cutting tool formed with an average layer thickness is widely used for continuous cutting and intermittent cutting of various steels and the like.

[0003]

On the other hand, in recent years, the use of FA in cutting has been remarkable, and there has been a strong demand for labor saving. Accordingly, cutting tools have been required to have a longer service life. In the case of the above-mentioned conventional surface-coated cermet cutting tool, at present, it is not possible to satisfy these requirements satisfactorily because the hard coating layer constituting the cutting tool has insufficient wear resistance.

[0004]

In view of the above, the present inventor has focused on the above-mentioned conventional surface-coated cermet cutting tool from the above-mentioned viewpoint, and has studied to improve the wear resistance of the hard coating layer constituting the cutting tool. As a result, at least one of the constituent layers of the hard coating layer except for the first layer in contact with the substrate surface is made of TiCN, and at least one of the TiCN layers is made of a conventional TiCN layer. The forming conditions are as follows: temperature: 800 to 880 ° C., reaction gas composition: volume%, TiCl ₄ : 2 to 10%, C
_{H 3 CN: 0.3~5%, H} 2: remainder, consists, Ti
Cl ₄ / CH ₃ CN: 1 to 9, H ₂ / TiCl ₄ : 8 or more, pressure: 30 to 300 torr, in particular, the condition where the ratio of TiCl _{4 to} CH ₃ CN in the reaction gas is increased, that is, Temperature: 700 to 860 ° C., reaction gas composition: by volume%, TiCl ₄ : 2 to 18%, C
_{H 3 CN: 0.2~2%, H} 2: remainder, consists, Ti
Cl ₄ / CH ₃ CN: 9.1 to 14, H ₂ / TiC
When formed under the following conditions: l ₄ : 4.5 or more, pressure: 30 to 300 torr, the TiCN layer formed as a result, when observed by X-ray diffraction, shows the above-mentioned conventional TiCN layer.
Under the conditions for forming the CN layer, the highest peak intensity appeared on the (220) plane, but now the highest peak intensity appears on the (422) plane, and there is a TiCN layer having the highest peak intensity on this (422) plane. The hard coating layer is (22
The research result showed that the abrasion resistance was further improved as compared with the hard coating layer in which the conventional TiCN layer having the highest peak intensity on the 0) plane was present.

[0005] The present invention has been made based on the above-mentioned research results and is based on a WC-based cemented carbide or TiCN.
Ti on the surface of a cermet substrate composed of a base cermet
C, TiN, TiCN, TiCNO, and Al ₂ O 3
In a surface-coated cermet cutting tool formed by forming a hard coating layer composed of two or more types of multiple layers by a chemical vapor deposition method, the constituent layers of the hard coating layer excluding the first layer in contact with the substrate surface Is composed of TiCN, and at least one of the TiCN layers is formed of X
T showing the highest peak intensity on the (422) plane in X-ray diffraction
A feature of the surface-coated cermet cutting tool is to improve the wear resistance of the hard coating layer by using iCN.

[0006]

Next, the cutting tool of the present invention will be described in detail with reference to examples. As a substrate, a WC-based cemented carbide substrate having a composition of WC-6% Co and a shape of CNMG432, and TiCN-15% WC-15% TaC-
A TiCN-based cermet substrate having a composition of 8% Co-8% Ni (or more, by weight%) and the same shape as the WC-based cemented carbide substrate is prepared, and a normal chemical vapor deposition apparatus is provided on the surface of the cermet substrate. A cutting tool made of the surface-coated cermet of the present invention (hereinafter, referred to as a coated cutting tool of the present invention) by forming a hard coating layer having the composition and the average layer thickness shown in Tables 2 to 5 under the conditions shown in Table 1 respectively. 1 to
18 and conventional surface-coated cermet cutting tools (hereinafter referred to as
Conventionally referred to as coated cutting tools) 1 to 18 were manufactured respectively.

[0007]

[Table 1]

[0008]

[Table 2]

[0009]

[Table 3]

[0010]

[Table 4]

[0011]

[Table 5]

The coated cutting tools 1 to 18 of the present invention and the conventional coated cutting tools 1 to 18 have the same composition and average layer thickness of the hard coating layer, respectively. The hard coating layers No. to No. 18 were subjected to X-ray diffraction (42
2) The difference is that at least one TiCN layer having the highest peak intensity on the surface exists. 1 and 2 show the results of X-ray diffraction measurement of the hard coating layers of the coated cutting tool 1 of the present invention and the conventional coated cutting tool 1, respectively.

Next, among the coated cutting tools 1 to 18 of the present invention and the conventional coated cutting tools 1 to 18 thus obtained,
Coated cutting tools 1 to 9 of the present invention and conventional coated cutting tools 1 to
For 9 Workpiece: SNCM439 (Hardness: H _B 280) round bar, Cutting speed:. 180 m / min, Feed: 0.3 mm, cut: 1.5 mm Dry continuous cutting test of steel in the conditions, And the coated cutting tools 10 to 18 of the present invention and the conventional coated cutting tools 10 to 1
For 8 Workpiece: SNCM439 (Hardness: H _B 280) round bar, Cutting speed:. 230 m / min, Feed: 0.2 mm / rev, cut:. 1 mm, dry continuous cutting of steel in the conditions Tests were performed, and in each test, the cutting time until the flank width of the cutting edge reached 0.3 mm was measured. Table 2 shows these measurement results.
-5.

[0014]

From the results shown in Tables 1 to 5 and FIGS. 1 and 2, from the results shown in FIGS. 1 to 5, the hard coating layer according to the present invention has at least one TiCN layer having the highest peak intensity on the (422) plane by X-ray diffraction. Each of the tools 1 to 18 is different from the conventional coated cutting tools 1 to 18 in which the TiCN layer, which is a constituent layer of the hard coating layer, is constituted by the TiCN layer in which the highest peak intensity appears on the (220) plane by X-ray diffraction. It shows that it has relatively good wear resistance and can be used for a long time. As described above, the surface-coated cermet cutting tool of the present invention has a hard coating layer that has excellent wear resistance and enables a prolonged service life. It can respond satisfactorily to labor saving.

[Brief description of the drawings]

FIG. 1 is a view showing an X-ray diffraction measurement result of a hard coating layer of a coated cutting tool 1 of the present invention.

FIG. 2 is a diagram showing an X-ray diffraction measurement result of a hard coating layer of the conventional coated cutting tool 1.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 16/00-16/56 C23C 14/00-14/58 B23B 27/14 B23P 15/28 C23C 28 / 04

Claims (1)

(57) [Claims] 1. A cermet substrate comprising a tungsten carbide-based cemented carbide or a titanium carbonitride-based cermet is provided on a surface of a titanium carbide, a nitride, a carbonitride, a carbonitride, and two kinds of aluminum oxides. In a cutting tool made of a surface-coated cermet obtained by forming a hard coating layer having a plurality of layers by a chemical vapor deposition method, at least one of constituent layers of the hard coating layer excluding a first layer in contact with a substrate surface. A hard coating comprising: a layer formed of titanium carbonitride; and at least one of the titanium carbonitride layers formed of titanium carbonitride exhibiting the highest peak intensity on a (422) plane in X-ray diffraction. Surface-coated cermet cutting tool with improved layer wear resistance.