JPH10237648A - Surface coated cutting tool excellent in wear resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface coated cutting tool in which a hard coating layer contg. titanium carbonitride layer excellent in wear resistance is formed. SOLUTION: In a surface coated cutting tool obtd. by forming a hard coating layer contg. at least one titanium carbonitride layer on the surface of a WC base cemented carbide or TiCN base cermet substrate, when the X-ray diffraction intensity of the (111) plane and the X-ray diffraction intensity of the (220) plane at optional point in the range from the edge part of a honing corresponding to the tip part of a nose R in the flank of the surface coated cutting tool to 0.5mm toward the thickness direction of the surface coated cutting tool are respectively defined as In111 and In220 , and the X-ray diffraction intensity of the (111) plane and the X-ray diffraction intensity of the (220) plane at the optical point in the center part of the flank of the surface coated cutting tool are respectively defined as Ic111 and Ic220 , the orientation properties of the titanium carbonitride layer by micoregion X-ray diffraction satisfy In111 /In220 > Ic111 /Ic220 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a WC-based cemented carbide or TiCN-based cermet substrate (hereinafter referred to as a substrate).
The present invention relates to a surface-coated cutting tool having excellent wear resistance, comprising a single hard coating layer containing at least one titanium carbonitride layer or a composite hard coating layer formed on the surface of the cutting tool.

[0002]

2. Description of the Related Art Conventionally, commercially available surface-coated cutting tools include a single hard coating layer made of titanium carbonitride or a carbonitride layer of titanium on the surface of a substrate by a chemical vapor deposition method. A surface-coated cutting tool formed by forming a composite hard coating layer composed of one or more of titanium carbide, nitride, carbonate and aluminum oxide layers is known. It is well known that it is used for continuous cutting and interrupted cutting of steel and cast iron.

For example, the surface of a substrate is subjected to X-ray diffraction (200)
A surface-coated cutting tool comprising a composite hard coating layer composed of an inner layer made of titanium carbide, nitride, and carbonitride having a maximum peak on the surface and an outer layer made of α-type aluminum oxide No. 63-89202), an inner layer made of a carbide, nitride, or carbonitride of titanium having a maximum peak on the (220) plane by X-ray diffraction on the surface of the substrate;
Surface-coated cutting tool formed with a composite hard coating layer composed of an outer layer made of aluminum oxide
195268), an inner layer made of titanium carbide, nitride, carbonitride, and carbonitride having a maximum peak on the (111) plane by X-ray diffraction on the substrate surface, and an outer layer made of κ-type aluminum oxide Surface-coated cutting tool formed by forming a composite hard coating layer composed of
368), and the like.

[0004]

However, in recent years, there has been a strong demand for labor saving and shortening of the cutting process, and with this, there has been a tendency for cutting to be performed under more severe conditions. Under cutting conditions, the cutting edge wears in a short time during cutting and reaches a service life in a relatively short time.

[0005]

Accordingly, the present inventors have developed a surface-coated cutting tool which is more excellent in abrasion resistance than conventional surface-coated cutting tools even when cutting is performed under such severe conditions. As a result of research, a surface-coated cutting tool having a hard coating layer including at least one layer of titanium carbonitride formed on the surface of a substrate, has a flank near the nose R and a flank near the flank. It is preferable that there is a difference in the orientation of the carbonitride layer of titanium at the center by micro-domain X-ray diffraction, and the surface coating cutting from the end of the honing corresponding to the tip of the nose R at the flank of the surface coating cutting tool. Honing corresponding to the tip of the nose R on the flank of the flank of the surface-coated cutting tool, where the X-ray diffraction intensity of the (111) plane at an arbitrary position within 0.5 mm in the thickness direction of the tool is In ₁₁₁ . End of At an arbitrary position in the thickness direction of the surface-coated cutting tool within the range of 0.5mm from (22
The X-ray diffraction intensity of the 0) plane is In ₂₂₀ , and the X-ray diffraction intensity of the (111) plane at an arbitrary position in the center of the flank of the surface-coated cutting tool is
Assuming that the X-ray diffraction intensity is Ic ₁₁₁ and the X-ray diffraction intensity of the (220) plane at an arbitrary position in the center of the flank of the surface-coated cutting tool is Ic ₂₂₀ , titanium carbonitride contained in the hard coating layer The orientation of the layer by the micro-domain X-ray diffraction is In.
_The surface-coated cutting tool satisfying ₁₁₁ / In ₂₂₀ > Ic ₁₁₁ / Ic ₂₂₀ shows characteristics superior in abrasion resistance as compared with the conventional one, and has a longer service life than before in cutting under severe conditions. That's the result of the research.

The present invention has been made based on the results of such research, and is directed to a cutting tool having a hard coating layer including at least one titanium carbonitride layer formed on a substrate surface. The orientation of the carbonitride layer of titanium contained in the layer by micro-domain X-ray diffraction was In ₁₁₁ / I
a surface-coated cutting tool that satisfies the formula n ₂₂₀ > Ic ₁₁₁ / Ic ₂₂₀ .

In the above surface-coated cutting tool, the titanium carbonitride layer is such that In ₁₁₁ > In ₂₂₀ and I
More preferably, the condition of c ₁₁₁ <Ic _{220 is} satisfied. Therefore, the present invention provides at least one
In a cutting tool having a hard coating layer including a titanium carbonitride layer, the orientation of the titanium carbonitride layer contained in the hard coating layer by micro-domain X-ray diffraction is In.
₁₁₁ / In ₂₂₀ > Ic ₁₁₁ / Ic ₂₂₀
A surface-coated cutting tool satisfying n ₁₁₁ > In ₂₂₀ and satisfying Ic ₁₁₁ <Ic ₂₂₀ .

In general, the nose R of a surface-coated cutting tool refers to a portion 2 'of the rake face 1 shown by oblique lines as shown in FIG. The tip 2 of the nose R indicates a curved portion at the end of the rake face 1 shown by a thick line in FIG. A honing 4 is formed at the boundary between the rake face 1 and the flank 3 of a normal surface-coated cutting tool, and in the present invention, "the honing end corresponding to the tip of the nose R on the flank is used to form the surface-coated cutting tool. "Within a range of up to 0.5 mm in the thickness direction of". " Further, in the present invention, the “central portion of the flank” refers to the central portion of the flank 3 exceeding 0.5 mm in the thickness direction from the honing end, and FIG.
Is a portion b indicated by oblique lines. The thickness of the titanium carbonitride layer is preferably in the range of 1 to 20 μm.

In the present invention, In ₁₁₁ / In ₂₂₀ > Ic ₁₁₁
/ Ic ₂₂₀ satisfies the reaction temperature in the chemical vapor deposition apparatus at a normal temperature (800 to 1000 ° C.).
, The reaction gas TiCl ₄ : 0.5 to 10% by volume, CH ₃ CN: 0.01 to 5.0% by volume, N ₂ : 0
50 volume% (if N ₂ is not included in some), the remaining H
It can be formed by adjusting the supply flow rate of the mixed gas consisting of ₂ to 3 to 10 times the supply flow rate of the conventional mixed gas.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS
0408, in weight%, WC-8% TiC-
WC-based cemented carbide having a composition of 10% TaC-6% Co and TiCN-15% WC-9% TaC-10
% Mo prepared TiCN-base cermet having a composition consisting of _{2 C-5% Ni-3} % Co, after having been subjected to honing, these as a base, using a chemical vapor deposition apparatus, in Table 1-2 on the surface of the substrate The hard coating layer shown was formed, and coated cutting tools 1 to 10 of the present invention and conventional coated cutting tools 1 to 10 were produced. Among the coated cutting tools 1 to 10 according to the present invention and the coated cutting tools 1 to 10 according to the present invention, the coated cutting tools 1 to 5 according to the present invention and the coated coated tools 1 to 5 according to the present invention are based on a WC-based cemented carbide, and the coated cutting tool according to the present invention. The cutting tools 6 to 10 and the conventionally coated cutting tools 6 to 10 are cutting tools having a TiCN-based cermet as a base.

The coating of the hard coating layer was carried out by supplying a normal gas supply amount under the following conditions. The TiCN hard coating layer of the present invention was coated at a gas supply amount of the conditions shown in Tables 1 and 2. went. TiC hard coating layer Reaction gas composition: 2% TiCl ₄ -5% CH ₄ —H ₂ Reaction temperature: 1040 ° C. Reaction pressure: 50 Torr

TiCN hard coating layer Reaction gas composition: 2% TiCl ₄ -0.6% CH ₃ CN—
20% N ₂ -H ₂ Reaction temperature: 840 ° C. Reaction pressure: 50 Torr

TiN hard coating layer Reaction gas composition: 2% TiCl ₄ -25% N ₂ —H ₂ Reaction temperature: 900 ° C. Reaction pressure: 200 Torr

Al ₂ O ₃ hard coating layer Reaction gas composition: 3% AlCl ₃ -6% CO ₂ —H ₂ Reaction temperature: 980 ° C. Reaction pressure: 50 Torr

[0015]

[Table 1]

[0016]

[Table 2]

With respect to the obtained coated cutting tools 1 to 10 of the present invention and the conventional coated cutting tools 1 to 10, the surface coated cutting tools are cut from the end of the honing corresponding to the tip of the nose R on the flank 3 shown in FIG. The X-ray diffraction intensity of the minute area of the (111) plane: In ₁₁₁ and the X-ray diffraction intensity of the minute area of the (220) plane: In ₂₂₀ at the position of the point A separated by 0.5 mm in the thickness direction of further flank 3 of the thickness of the central portion of the (111) plane of the micro area X-ray diffraction intensity of the position of point B: Ic ₁₁₁ and (220) plane of the micro area X-ray diffraction intensity: the Ic ₂₂₀ is measured, the minute region X-ray diffraction intensity ratio I
The values of n ₁₁₁ / In ₂₂₀ and Ic ₁₁₁ / Ic ₂₂₀ were determined, and the results are shown in Tables 3 and 4. All the values of the X-ray diffraction intensity in the minute area measured here are relative values. The point A was selected as the measurement position of the micro-region X-ray diffraction intensity because the point “0. 0” in the thickness direction of the surface-coated cutting tool from the end of the honing corresponding to the tip of the nose R on the flank. This is because it is the position that is most easily measured within the range of up to 5 mm. Further, the position of point B was selected as the measurement position of the X-ray diffraction intensity in the minute area because of the “center part of the flank”. This is because it is the most representative position.

Work material: Round bar of SNCM439 (hardness: HB260) Cutting speed: 220 m / min Feed: 0.40 mm / rev Cutting depth: 2.0 mm Cutting time: 25 min Cutting oil: None A continuous cutting test of steel was performed to observe the damage of the cutting edge and measure the flank wear of the cutting edge of the cutting tool. The results are shown in Tables 3 and 4.

Further, using the coated cutting tools 6 to 10 of the present invention and the conventional coated cutting tools 6 to 10, a work material: a round bar of SNCM439 (hardness: HB260) Cutting speed: 250 m / min Feed: 0.25 mm / Rev Depth of cut: 1.5mm Cutting time: 35min Cutting oil: None A continuous cutting test of steel was performed to observe the damage state of the cutting edge and to check the flank wear of the cutting edge of the tool that performed the cutting. The measurement was performed, and the results are shown in Tables 3 and 4.

[0020]

[Table 3]

[0021]

[Table 4]

[0022]

According to the results shown in Tables 1 to 4, (1)
The coated cutting tool 1 of the present invention and the conventional coated cutting tool 1 are hard-coated.
Despite the same composition and thickness of the overlayer, X
When the line diffraction intensity ratio is In₁₁₁/ In₂₂₀> Ic ₁₁₁/ Ic
₂₂₀The coated cutting tool 1 of the present invention satisfying the relationship of
₁₁₁/ In₂₂₀≤Ic₁₁₁/ Ic₂₂₀Satisfy the relationship
Chipping compared to conventional coated cutting tool 1
And excellent wear resistance, greatly extending the life of cutting tools
And improved with the coated cutting tools 2 to 10 of the present invention.
Same effect when comparing conventional coated cutting tools 2-10
(2) Also, the coated cutting tools 1 to 10 of the present invention
Also, the X-ray diffraction intensity ratio is In₁₁₁/ In₂₂₀> Ic
₁₁₁/ Ic₂₂₀And In₁₁₁> In₂₂₀And
Ic_{11 1}<Ic₂₂₀Coating cutter of the present invention that satisfies the relationship of
The components 1, 2, 4, 6, 8, and 10 consist of the composition of the hard coating layer and
Despite the fact that the film thickness is almost the same,₁₁₁/ I
n₂₂₀≤Ic₁₁₁/ Ic₂₂₀And In₁₁₁≤
In₂₂₀And Ic₁₁₁≧ Ic₂₂₀Conventional that satisfies the relationship
Compared to coated cutting tools 1, 2, 4, 6, 8, 10
Without pinging, shows particularly excellent wear resistance,
It can be seen that the life of the cutting tool has been significantly improved.

Therefore, the surface-coated cutting tool of the present invention can contribute to the development of industry because it can reduce the number of times of replacing the cutting tool and the like, increase the work efficiency and reduce the cost, as compared with the conventional surface-coated cutting tool. Things.

[Brief description of the drawings]

FIG. 1 is an arbitrary position within a range from the end of a honing corresponding to the tip of a nose R on a flank of a surface-coated cutting tool of the present invention to 0.5 mm in a thickness direction of the surface-coated cutting tool. FIG. 4 is an explanatory view of an arbitrary position in a central portion of a flank of the surface-coated cutting tool.

[Explanation of symbols]

 1 Rake face 2 Tip of nose R 2 'Nose R 3 Flank

Claims (2)

[Claims] 1. A surface-coated cutting tool comprising a WC-based cemented carbide or TiCN-based cermet substrate (hereinafter referred to as a substrate) and a hard coating layer including at least one titanium carbonitride layer formed on the surface thereof. X-ray diffraction of (111) plane at any position within 0.5 mm in the thickness direction of the surface-coated cutting tool from the end of the honing corresponding to the tip of the nose R at the flank of the coated cutting tool The strength is In ₁₁₁ , at any position within a range from the end of the honing corresponding to the tip of the nose R at the flank of the flank of the surface-coated cutting tool to 0.5 mm in the thickness direction of the surface-coated cutting tool ( the X-ray diffraction intensity of 220) an in _220, in an X-ray diffraction intensity of the (111) plane of an arbitrary position in the central portion of the flank of the surface-coated cutting tool of the Ic _111, flank of the surface-coated cutting tool Any position (220) plane Ic ₂₂₀ the X-ray diffraction intensity of the section, and when, orientation by micro area X-ray diffraction of the carbonitride layer of titanium at least one layer included in the hard coating layer, excellent surface-coated cutting tool wear resistance which is a carbonitride layer of titanium satisfying _{in 111 / in 220> Ic 111} / Ic 220. 2. In ₁₁₁ > In ₂₂₀ and Ic ₁₁₁ <I
hard layer surface-coated cutting tool having excellent wear resistance according to claim 1, characterized in that the c _220.