JP3266047B2 - Surface coated cemented carbide cutting tool with excellent interlayer adhesion with hard coating layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a Ti compound layer and an α-type crystal aluminum oxide (hereinafter referred to as α-Al ₂ O ₃ ) layer constituting a hard coating layer having excellent interlayer adhesion. Therefore, a cutting tool made of a surface-coated cemented carbide (hereinafter referred to as a coated carbide tool) that exhibits excellent cutting performance over a long period of time without peeling of the hard coating layer even when used for high-speed cutting of steel or cast iron, for example. It is about).

[0002]

2. Description of the Related Art Conventionally, generally, for example, Japanese Patent Application Laid-Open No. 6-315
03, JP-A-6-316758, and JP-A-7-216549, etc.
A titanium carbide (hereinafter, referred to as TiC) layer on a surface of a tungsten carbide-based cemented carbide substrate (hereinafter, referred to as a cemented carbide substrate);
Titanium nitride (hereinafter also referred to as TiN) layer, titanium carbonitride (hereinafter referred to as TiCN) layer, titanium carbonate (hereinafter referred to as TiCO) layer, titanium oxynitride (hereinafter referred to as TiN)
O) layer and titanium carbonitride (hereinafter referred to as TiCN).
O) or one or more of these layers
There is known a coated carbide tool in which a hard coating layer composed of a compound layer and an α-Al ₂ O ₃ layer is formed by chemical vapor deposition and / or physical vapor deposition with an average layer thickness of 3 to 20 μm. It is also known that coated carbide tools are used for continuous or interrupted cutting of steel, cast iron, and the like.

[0003]

On the other hand, recent cutting devices
High-performance and high-power
There is also a strong demand for high-speed cutting.
In the conventional coated carbide tools described above,
Among the hard coating layers constituting α-Al_Two O _Three Layers
Excellent oxidation resistance and thermal stability, with high hardness
However, the interlayer adhesion with a Ti compound layer as another constituent layer is not sufficient.
For continuous cutting or intermittent cutting of steel or cast iron, for example,
When abrasion is performed at high speed, the hard coating layer tends to peel.
This leads to a short service life in a relatively short time.
It is.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above viewpoint, attention is paid to the α-Al ₂ O ₃ layer constituting the hard coating layer of the coated cemented carbide tool, and in order to improve the interlayer adhesion between the α-Al ₂ O ₃ layer and the Ti compound layer which is another constituent layer. as a result of research, the (1) titanium oxide, there are mainly Ti ₂ O _3, TiO _2, and 3 types represented by TiO chemical formulas, these Ti ₂ O _3, TiO _2, and each of the TiO The titanium oxide layer containing Ti as a main component can be formed by using either a chemical vapor deposition method or a physical vapor deposition method to form (a) a titanium oxide layer containing Ti ₂ O ₃ as a main component (hereinafter referred to as a Ti ₂ O ₃ layer). gas composition (in% by volume, hereinafter the same) -TiCl _{4:
0.4~10%, Co 2: 0.4~10%} , N 2: 5~
60%, H ₂ : remaining, ambient temperature: 800 to 1100 ° C., atmospheric pressure: 30 to 500 Torr, (b) a titanium oxide layer containing TiO ₂ as a main component (hereinafter referred to as T
iO called layer ₂₎ reaction gas composition _{-TiCl 4: 0.4~10%, O 2} :
0.4 to 10%, inert gas: remaining, ambient temperature: 800 to 1100 ° C., atmospheric pressure: 30 to 500 Torr, (c) a titanium oxide layer containing TiO as a main component (hereinafter referred to as Ti
Called O layer) reaction gas composition _{-TiCl 4: 0.4~10%, CO 2} :
0.1 to 1%, H _2: remainder, ambient temperature: 800 to 1100 ° C., atmospheric pressure: 30～500Torr, can be formed in the condition. (2) The above-mentioned Ti ₂ O ₃ layer, TiO ₂ layer, and TiO
The layer was X-ray diffraction using Cuka radiation as a source,
(A) The Ti ₂ O ₃ layer has a thickness of 34.9 ± as shown in FIG.
X at which the highest diffraction peak height appears at one diffraction angle (2θ)
X-ray diffraction pattern, (b) TiO ₂ layer has an X-ray diffraction pattern in which the highest diffraction peak height appears at a diffraction angle (2θ) of 28.7 ± 1 degree as shown in FIG. 2, and (c) TiO layer has As shown in FIG. 3, an X-ray diffraction pattern in which the highest diffraction peak height appears at a diffraction angle (2θ) of 43.7 ± 1 degree is shown. (3) Of these titanium oxide layers, the Ti ₂ O ₃ layer showing the X-ray diffraction pattern of FIG.
Or when interposed between the Ti compound layer and the α-Al ₂ O ₃ layer constituting the conventional hard coating layer formed by using the physical vapor deposition method, the Ti compound layer and the α-Al ₂ O ₃ layer Since the Ti ₂ O ₃ layer has the property of being extremely strongly adhered to both of these layers, it has a high interlayer adhesion. Therefore, even when high-speed cutting of steel or cast iron, for example, peeling of the hard coating layer occurs. While excellent cutting performance is exhibited over a long period without occurrence, the TiO ₂ layer showing the X-ray diffraction pattern of FIG. 2 and the TiO layer showing the X-ray diffraction pattern of FIG. Layer and α-Al ₂
Adhesion to the O ₃ layer is low, and desired interlayer adhesion cannot be obtained. The research results shown in (1) to (3) above were obtained.

The present invention has been made on the basis of the above research results, and a TiC layer and a T
Ti comprising one or more of an iN layer, a TiCN layer, a TiCO layer, a TiNO layer, and a TiCNO layer
In a coated cemented carbide tool obtained by chemical vapor deposition and / or physical vapor deposition of a hard coating layer composed of a compound layer and an α-Al ₂ O ₃ layer with an average layer thickness of 3 to 20 μm, the Ti compound layer and the Cuk is interposed between the α-Al ₂ O ₃ layers.
In X-ray diffraction using α-rays as a radiation source, a Ti ₂ O ₃ layer showing an X-ray diffraction pattern in which the highest diffraction peak height appears at a diffraction angle (2θ) of 34.5 ± 1 degree is 0.1 to 0.1%. A hard coating layer formed by chemical vapor deposition or physical vapor deposition with an average layer thickness of 5 μm is characterized by a coated carbide tool having excellent interlayer adhesion.

[0006] In the coated carbide tool of the present invention,
Ti constituting the hard coating layer_Two O_Three Average layer thickness of 0.1
The reason that the thickness is set to?
Al _TwoO_ThreeThe desired excellent interlayer between the layer and the Ti compound layer
Adhesion cannot be ensured, while its thickness is 5 μm
Over the cutting edge, chipping or chipping (small chipping)
This is because it is easier to grow. Also hard
The reason why the average layer thickness of the coating layer is 3 to 20 μm is that the layer thickness is
At 3 μm, the desired excellent wear resistance can be secured.
On the other hand, if the layer thickness exceeds 20 μm,
Because chipping and chipping are likely to occur.
You.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the coated carbide tool of the present invention will be specifically described with reference to examples. Medium-sized WC powder having an average particle diameter of 2.8 μm, 4.9 μm as the raw material powder
m of coarse WC powder, 1.5 μm of (Ti, W) C (the same in weight ratio, hereinafter, TiC / WC = 30/70) powder,
1.2 μm (Ti, W) CN (TiC / TiN / W
C = 24/20/56) powder, 1.2 μm (Ta,
Nb) C (TaC / NbC = 90/10) powder and Co powder of 1.1 μm were prepared, and these raw material powders were blended in the composition shown in Table 1, wet-mixed in a ball mill for 72 hours, and dried. After that, ISO ・ CNMG12040
8 (for carbide substrates A to D) and SEEN42AFTN
Press molded into a green compact having the shape defined in No. 1 (for the super hard substrate E), and the green compact was vacuum-sintered under the conditions shown in Table 1 to produce super hard substrates A to E, respectively. Further, the above-mentioned super hard substrate B was subjected to 100 Torr CH.
After holding at a temperature of 1400 ° C. for 1 hour in a ₄ gas atmosphere, a slow cooling carburization treatment is performed, and after the treatment, carbon and Co adhering to the surface of the carbide substrate are removed from the surface by acid and barrel polishing. Maximum Co content at 11 μm: 1
A Co-enriched zone of 5.9% by weight and a depth of 42 μm was formed on the surface of the substrate. In addition, the above-mentioned carbide substrates A and D include:
As-sintered, a Co-enriched zone having a maximum Co content of 9.1% by weight and a depth of 23 μm was formed on the surface at a position 17 μm from the surface, and the remaining carbide substrates C and E were formed. Has no formation of the Co-enriched zone and has an overall homogeneous structure. Table 1 shows the internal hardness (Rockwell hardness A scale) of each of the carbide substrates A to E.

Then, the surfaces of these super-hard substrates A to E are honed, and a conventional chemical vapor deposition apparatus is used. Table 1 (1-TiCN in the table corresponds to JP-A-6-8010
Under the conditions shown in Table 3 and under the conditions shown in Table 3, and under the conditions shown in Tables 3 and 4, the p-TiCN has a normal granular crystal structure. By forming a hard coating layer composed of a Ti compound layer having a layer thickness and an α-Al ₂ O ₃ layer, the coated carbide tools 1 to 10 of the present invention and a conventional coated carbide having no formation of a Ti ₂ O ₃ layer Tools 1 to 10 were manufactured respectively.

Next, for the above-mentioned coated carbide tools 1 to 9 of the present invention and conventional coated carbide tools 1 to 9, a work material: a round bar of JIS SCM440 (hardness: HB 220), a cutting speed: 350 m / min. Infeed: 3 mm Feed: 0.4 mm / rev. , Cutting time: 10 minutes, Dry high-speed continuous cutting test of alloy steel under the following conditions: Work material: JIS SNCM439 (Hardness: HB 230)
Square material, Cutting speed: 180 m / min. Infeed: 3 mm, 0 feed: 0.25 mm / rev. The cutting speed was 5 minutes. A dry high-speed intermittent cutting test was performed on the alloy steel under the following conditions, and the flank wear width of the cutting edge was measured in each cutting test. Table 5 shows the results of these measurements. Further, regarding the coated carbide tool 10 of the present invention and the conventional coated carbide tool 10, a work material: JIS S25C (hardness: HB150), a cutting speed: 200 m / min. A dry high-speed milling test of mild steel was performed under the following conditions: cutting depth: 2 mm, feed: 0.15 mm / tooth, cutting time: 10 minutes, and the flank wear width of the cutting edge was measured. The measurement results are also shown in Table 5.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

[0013]

[Table 4]

[0014]

[Table 5]

[0015]

From the results shown in Tables 3 to 5, it can be seen that Ti ₂ O _{3 is present} between the Ti compound layer and the α-Al ₂ O ₃ layer in the hard coating layer.
The coated carbide tools 1 to 10 of the present invention having a layer interposed therebetween have a Ti
Excellent interlaminar adhesion between the compound layer and the α-Al ₂ O ₃ layer. Excellent cutting without hard coating layer peeling even in high-speed continuous cutting or high-speed interrupted cutting of steel, which is severe cutting conditions. On the other hand, the conventional coated carbide tools 1 to 10 have a Ti compound layer and α-Al
It is clear that, due to insufficient interlayer adhesion with the ₂ O ₃ layer, any of the hard coating layers peeled off in a relatively short time, which led to a long service life. As described above, the coated carbide tool according to the present invention has a T
Since the i-compound layer and the α-Al ₂ O ₃ layer have excellent interlayer adhesion, continuous cutting or interrupted cutting under ordinary conditions such as steel or cast iron, of course, these cutting can be performed at high speed. Even if it is performed, excellent cutting performance is exhibited over a long period of time, so that it can sufficiently cope with high-speed cutting and contributes to labor saving.

[Brief description of the drawings]

FIG. 1 is a view showing an X-ray diffraction pattern of a Ti ₂ O ₃ layer.

FIG. 2 is a diagram showing a TiO ₂ layer X-ray diffraction pattern.

FIG. 3 is a diagram showing an X-ray diffraction pattern of a TiO layer.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C23C 16/30 C23C 16/30 30/00 30/00 C (72) Inventor Keiji Nakamura 1-297 Kitabukurocho, Omiya City, Saitama Prefecture (72) Inventor Takashi Oshika 1-297 Kitabukurocho, Omiya City, Saitama Prefecture Mitsubishi Materials Real Research Institute (56) References JP-A-10-130842 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) C23C 28/04 B23B 27/14 B23P 15/28 C23C 14/06 C23C 14/08 C23C 16/30 C23C 30/00

Claims (1)

(57) [Claims] 1. One of a titanium carbide layer, a titanium nitride layer, a titanium carbonitride layer, a titanium carbonate layer, a titanium oxynitride layer, and a titanium carbonitride oxide layer on a surface of a tungsten carbide-based cemented carbide substrate. Or a surface-coated cemented carbide obtained by chemical vapor deposition and / or physical vapor deposition of a hard coating layer composed of a Ti compound layer composed of two or more kinds and an aluminum oxide layer of α-type crystal with an average layer thickness of 3 to 20 μm In a cutting tool manufactured, a diffraction angle (2θ) of 34.5 ± 1 degrees was obtained by X-ray diffraction using a Cukα ray as a radiation source, interposed between the Ti compound layer and the aluminum oxide layer of the α-type crystal. A titanium oxide layer showing an X-ray diffraction pattern in which the highest diffraction peak height appears is formed by chemical vapor deposition or physical vapor deposition with an average layer thickness of 0.1 to 5 μm. Having surface coating super Hard alloy cutting tool.