JPH08118106A - Cutting tool coated with hard layer - Google Patents

Abstract

PURPOSE: To provide a cutting tool coated with a hard layer, which shows excellent machinability in continuous cutting at a high speed exceeding a specified value. CONSTITUTION: This cutting tool is a hard layer coated cutting tool which is coated with a single hard layer of composite carbide nitride of composition of Ti and Si composed of (Ti1-x Six ) (C1-y Ny )z [however, 0.01<=x<=0.45, 0.01<=y<=1.0, 0.5<=z<=1.34] or coated with a single hard layer of composite nitride on the surface of a tip base body made of WC group cemented carbide alloy base body or TiCN group cermet and can perform high speed cutting at a speed higher than about 250m/min or more.

Description

Detailed Description of the Invention

[0001]

This invention has a cutting speed of 250 m.
The present invention relates to a hard-layer-coated cutting tool that exhibits excellent cutting performance for high-speed continuous cutting exceeding 100 rpm.

[0002]

2. Description of the Related Art Generally, a substrate made of WC-based cemented carbide containing WC as a main component (hereinafter referred to as WC-based cemented carbide substrate).
Alternatively, on the surface of a base body composed of cermet containing TiCN as a main component (hereinafter referred to as TiCN base cermet base body),
A hard-layer-coated cutting tool formed by coating a single hard layer of (Ti _0.5 Si _0.5 ) C is known (Japanese Patent Laid-Open No. 3065/1991).
No. 50).

[0003]

However, the conventional hard layer-coated cutting tool coated with the (Ti _0.5 Si _0.5 ) C hard layer has insufficient wear resistance when used for high-speed continuous cutting. Therefore, a satisfactory service life is not obtained.

[0004]

Therefore, the present inventor has conducted research to solve the above problems and obtain a hard-layer-coated cutting tool that exhibits a longer life even when used for high-speed continuous cutting. As a result, (Ti _1-x Si _x ) (C _1-y ) was formed on the surface of the WC-based cemented carbide substrate or the TiCN-based cermet substrate.
N _y ) _z [where 0.01 ≦ x ≦ 0.45, 0.01 ≦ y ≦ 1.0,
0.5 ≤ z ≤ 1.34] Ti and Si composite carbonitride single hard layer or hard layer coated cutting tool coated with single nitride composite hard layer has been conventionally used in high-speed continuous cutting. It has been found that the wear resistance is even better and the service life is longer.

The present invention has been made on the basis of the above findings, and is based on the WC-based cemented carbide substrate or TiCN.
On the surface of the base cermet substrate, (Ti _1-x Si _x ) (C
_1-y N _y ) _z [where 0.01 ≦ x ≦ 0.45, 0.01 ≦ y ≦ 1.
[0, 0.5 ≤ z ≤ 1.34], and is characterized by a hard carbon-nitride single hard layer of Ti and Si or a hard layer-coated cutting tool coated with a single hard nitride composite layer.

The values of x, y and z are limited as described above, because desired wear resistance cannot be obtained when x <0.01 and x> 0.45, and y <0. 01, y>
When 1.0, the desired fracture resistance cannot be obtained, and when z <0.5, the desired abrasion resistance cannot be obtained, and when z> 1.34, the desired fracture resistance cannot be obtained. This is because the property is deteriorated and peeling easily occurs. (Ti
_{1-x Si x) (C} 1-y N y) x in _z, y, more preferably in the range of z is, 0.01 ≦ x ≦ 0.30,0.3 ≦ y ≦ 0.7,
0.9 ≦ z ≦ 1.1. Therefore, a more preferable single hard layer formed on the surface of a WC-based cemented carbide substrate or a TiCN-based cermet substrate is a Ti / Si composite carbonitride single hard layer. Further, the film thickness of the single hard layer of the hard layer-coated cutting tool of the present invention is preferably in the range of 1 to 10 μm.

In order to form a single hard layer in the hard layer-coated cutting tool of the present invention, it can be formed by an arc discharge type ion plating method, a magnetron sputtering method or the like. In order to form a single hard layer by the arc discharge type ion plating method, first, arc discharge is generated on a target of a mixture of Ti and Si in a vacuum apparatus to vaporize and ionize Ti and Si. At the same time, a non-metal gas (nitrogen gas and hydrocarbon gas) was introduced into the equipment, and (Ti _1-x
Si _x ) (C _1-y N _y ) _z [where 0.01 ≦ x ≦ 0.45,
0.01≤y≤1.0, 0.5≤z≤1.34]. The ratio of Ti and Si is the target Ti / S
The i ratio and the metal / gas component ratio are controlled by adjusting the metal evaporation amount / gas introduction amount or by changing the substrate voltage.

In order to form a single hard layer by the magnetron sputtering method, first, a target of a mixture of Ti and Si in a vacuum apparatus is sandwiched and made to face each other. Next, a non-metal gas (nitrogen gas and hydrocarbon gas) is introduced into the apparatus to cause glow discharge between opposed targets. Ti
On a cutting tool substrate with a negative substrate voltage applied by sputtering and ionizing Si and Si (Ti _1-x Si _x )
(C _1-y N _y ) _z [where 0.01 ≦ x ≦ 0.45, 0.01 ≦ y
≤1.0, 0.5 ≤z≤1.34]. The Ti / Si ratio is controlled by adjusting the Ti / Si ratio of the target, and the metal / gas component ratio is controlled by adjusting the metal evaporation amount / gas introduction amount or by changing the substrate voltage.

[0009]

EXAMPLES Next, the hard layer-coated cutting tool of the present invention will be specifically described based on Examples. Example 1 A WC-based WC-based cemented carbide chip having a shape of SNGA120408 equivalent to ISO standard P30, a mixture target of Ti and Si in the ratios shown in Table 1 and a Ti target were prepared.

This WC-based cemented carbide tip was mounted in the upper part of a normal ion plating apparatus, while in the lower part of the ion plating apparatus, a mixture of Ti and Si in the ratio shown in Table 1 was used. With the target attached, exhaust the inside of the ion plating device in such a state to 1 ×
Maintaining a vacuum of 10 ⁻⁵ Torr, heating rate: 6 ° C./mi
n. Then, the temperature was raised to 700 ° C., and then, while maintaining this temperature, it was maintained in an Ar gas atmosphere of 5 × 10 ⁻² Torr for ion cleaning.

Thereafter, the ratios of Ti and Si shown in Table 1 were used.
Arc discharge is generated on the mixture target of No. 1 to heat and vaporize Ti and Si for ionization, and nitrogen gas and acetylene gas in the ratios shown in Table 1 are introduced from the supply port to obtain the negative substrate voltage shown in Table 1. The WC-based cemented carbide chips have the film thicknesses shown in Table 2 and the values of x, y and z shown in Table 2 (Ti _1-x Si _x ) The coated chips 1 to 10 of the present invention, the comparative coated chips 1 to 7 and the conventional coated chip 1 coated with a (C _{1 -y} N _y ) _z single hard layer were produced. The values of x, y and z in the (Ti _1-x Si _x ) (C _1-y N _y ) _z single hard layer were determined by EPMA analysis.

Using these coated chips 1 to 10 of the present invention, comparative coated chips 1 to 7 and conventional coated chip 1, a continuous dry cutting test was carried out under the following conditions. Continuous dry cutting test conditions Work material: JIS standard SNCM439 (Brinell hardness: 2
50) round material, cutting speed: 250 m / min, feed: 0.3 mm / rev. , Depth of cut: 2.0 mm, continuous dry cutting was performed, and the life when the maximum wear width of the flank of the cutting edge was 0.3 mm was taken as the life, and the time (minute) to reach the life and the wear pattern were measured. The measurement results are shown in Table 2.

[0013]

[Table 1]

[0014]

[Table 2]

From the results shown in Table 2, it is understood that the coated chips 1 to 10 of the present invention are superior in cutting characteristics to the comparative coated chips 1 to 7 and the conventional coated chip 1.

Example 2 TiCN-12% WC-8% Co-8% MoC-7% N
i-5% TaC composition, ISO standard SNGA12
A TiCN-based cermet chip having a shape of 0408, a mixture target of Ti and Si in the ratios shown in Table 3 and a Ti target were prepared.

This TiCN-based cermet chip tip was mounted in the upper part of a normal ion plating apparatus, while in the lower part of the ion plating apparatus, a mixture of Ti and Si in the ratio shown in Table 3 was used. With the target mounted, the inside of the ion plating apparatus was evacuated in such a state to maintain a vacuum of 1 × 10 ⁻⁵ Torr, and the temperature rising rate was 6 ° C./min. Then, the temperature is raised to 700 ° C., and then while maintaining this temperature, A of 5 × 10 ^-2 Torr
It was held in an r gas atmosphere for ion cleaning.

Then, the ratios of Ti and Si shown in Table 3 were used.
Arc discharge is generated on the mixture target of No. 1 to heat and vaporize Ti and Si for ionization, and nitrogen gas and acetylene gas in the ratios shown in Table 3 are introduced from the supply port to obtain the negative substrate voltage shown in Table 3. The TiCN-based cermet chip has a film thickness shown in Table 4 on the surface of the substrate, and x, y shown in Table 4 are applied.
And (Ti _1-x Si _x ) (C
_1-y N _y ) _{z A} single coated chip 1 of the present invention coated with a single hard layer
1 to 20, comparative coated chips 8 to 14 and conventional coated chip 2 were produced. The above (Ti _1-x Si _x ) (C
The values of x, y and z in the _1-y N _y ) _z single hard layer were obtained by analysis by EPMA.

Using these coated chips 11 to 20 of the present invention, comparative coated chips 8 to 14 and conventional coated chip 2,
A continuous dry cutting test was carried out under the following conditions.

Continuous dry cutting test conditions Work material: JIS standard SNCM439 (Brinell hardness: 2
50) round material, cutting speed: 300 m / min, feed: 0.2 mm / rev. , Depth of cut: 2.0 mm, continuous dry cutting was performed, and the life when the maximum wear width of the flank of the cutting edge was 0.3 mm was taken as the life, and the time (minute) to reach the life and the wear pattern were measured. The measurement results are shown in Table 4.

[0021]

[Table 3]

[0022]

[Table 4]

From the results shown in Table 4, it can be seen that the coated chips 11 to 20 of the present invention are superior in cutting performance to the comparative coated chips 8 to 14 and the conventional coated chip 2.

[0024]

From the results shown in Examples 1 and 2 above,
The hard layer-coated cutting tool of the present invention has more excellent performance than the conventional hard layer-coated cutting tool, and brings an industrially excellent effect.

Claims (2)

[Claims] 1. A surface of a WC-based cemented carbide substrate is provided with (Ti _1-x
Si _x ) (C _1-y N _y ) _z [where 0.01 ≦ x ≦ 0.45,
0.01≤y≤1.0, 0.5≤z≤1.34]
A hard-layer-coated cutting tool characterized by coating a composite carbonitride single hard layer or a composite nitride single hard layer of Si and Si. 2. The surface of a TiCN-based cermet substrate is provided with (T
i _1-x Si _x ) (C _1-y N _y ) _z [where 0.01 ≦ x ≦
0.45, 0.01 ≤ y ≤ 1.0, 0.5 ≤ z ≤ 1.34] Ti and Si composite hard carbonitride single hard layer or a hard layer characterized by coating a single composite nitride hard layer Coated cutting tool.