JP2007160426A - Pore-free surface coated cermet cutting throw-away tip having hard coating layer exhibiting excellent chipping resistance in high speed cutting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pore-free coated cutting tip having a hard coating layer exhibiting excellent chipping resistance in high speed cutting. <P>SOLUTION: In this pore-free coated cutting tip fitted to the tool body by clamping and fastening using a clamp piece, a hard coating layer including: a Ti compound layer as a bottom layer; and a two-phase mixed oxide layer (Al<SB>2</SB>O<SB>3</SB>-ZrO<SB>2</SB>layer) of aluminum oxide and zirconium oxide as a top layer is formed on the surface of a tip base by vapor deposition. On the whole surface of the two-phase mixed oxide layer (Al<SB>2</SB>O<SB>3</SB>-ZrO<SB>2</SB>layer)of the top layer, an abrasive material layer made of titanium nitride layer is formed with a means layer thickness ranging from 0.5 to 5 μm by vapor deposition. In this state, by a wet blast, polishing liquid where Al<SB>2</SB>O<SB>3</SB>fine grains are mixed is injected as an injected polishing material, thereby polishing the surface of the two-phase mixed oxide layer (Al<SB>2</SB>O<SB>3</SB>-ZrO<SB>2</SB>layer) of the top layer with the abrasive material layer of the clamp piece abut surface part left undone so that the surface roughness is Ra:0.2 μm or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a cutting throwaway tip made of a surface-less cermet having a hard coating layer that exhibits excellent chipping resistance, particularly when used for high-speed cutting of various steels and cast irons (hereinafter referred to as a coated cutting tip). ).

Conventionally, in general, as shown in a schematic perspective view in FIG. 3, a substrate composed of tungsten carbide (hereinafter referred to as WC) based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) based cermet (hereinafter referred to as these). On the entire surface of the rake face and flank including the cutting edge ridge line portion of the chip base)
As a lower layer, a titanium carbide (hereinafter referred to as TiC) layer, a titanium nitride (hereinafter also referred to as TiN) layer, a titanium carbonitride (hereinafter referred to as TiCN) layer, a titanium carbonate (hereinafter referred to as TiCO) layer And a Ti compound layer comprising one or more of titanium carbonitride oxide (hereinafter referred to as TiCNO) layers and having an overall average layer thickness of 3 to 20 μm,
As an upper layer, a two-phase mixed oxide layer (hereinafter referred to as Al ₂ O ₃ —ZrO) having an average layer thickness of 1 to 15 μm and having a two-phase mixed oxide structure of aluminum oxide and zirconium oxide in a state of chemical vapor deposition. ₂ layers)
A coated cutting tip is known which is formed by vapor-depositing a hard coating layer composed of the above, and the coated cutting tip is a tool body, for example, a tip portion of a shank portion as shown in a schematic perspective view in FIG. In the state where the tip of the clamp piece is brought into contact with the upper surface of the chip, and is clamped and fixed by tightening a clamp screw provided at the rear of the clamp piece, for example, various steels and cast irons. It is well known that it is used for continuous cutting and interrupted cutting.

The two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) is known to be formed by chemical vapor deposition under the following conditions.
(B) Reaction gas composition (volume%)
AlCl ₃ : 1 to 10%,
ZrCl _4: 0.01~10%,
CO _2: 1~30%,
HCl: 1-30%,
H ₂ S: 0.01~1%,
H ₂ : Remaining
(B) Reaction atmosphere temperature: 900 to 1050 ° C.
(C) Reaction atmosphere pressure: 4 to 70 kPa (30 to 525 torr),

In the above-mentioned coated cutting tip, the constituent layer of the hard coating layer generally has a granular crystal structure, and the TiCN layer constituting the Ti compound layer as the lower layer is intended to improve the strength of the layer itself. In a normal chemical vapor deposition apparatus, a gas mixture containing organic carbonitrides is used as a reaction gas, and it is formed by chemical vapor deposition at an intermediate temperature range of 700 to 950 ° C. so that it has a vertically grown crystal structure. It is also known to do.

Furthermore, it is also known to smooth the surface of the upper layer constituting the hard coating layer of the coated cutting tip by wet blasting for the purpose of improving the cutting performance.
JP 2000-334605 A JP 2004-42150 A Japanese Patent Laid-Open No. 6-8010 JP-A-8-276305

  In recent years, the performance of cutting machines has been remarkable. On the other hand, there has been a strong demand for labor saving and energy saving and further cost reduction for cutting work. The cutting tip has no problem when it is used for continuous cutting or intermittent cutting under normal conditions such as steel or cast iron, but the cutting speed is 350 m / min. When used for cutting at a high speed exceeding 1, the two-phase mixed oxide layer constituting the upper layer of the hard coating layer is likely to chip (small chipping), and as a result, used in a relatively short time. The current situation is that it reaches the end of its life.

Therefore, the present inventors pay attention to the coated cutting tip in which the above-described two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) constitutes the upper layer of the hard coating layer from the above viewpoint, In particular, as a result of research to improve the chipping resistance of the Al ₂ O ₃ —ZrO ₂ layer,
(A) On the surface of the Al ₂ O ₃ —ZrO ₂ layer constituting the upper layer of the hard coating layer in the above-mentioned conventional coated cutting tip, the ratio of the wet blast to the total amount of water as the spray abrasive When a polishing liquid containing 15 to 60% by mass of aluminum oxide (hereinafter referred to as Al ₂ O ₃ ) fine particles is sprayed and polished, the Al ₂ O ₃ —ZrO ₂ layer is in compliance with JIS B0601-1994. (The following surface roughness is a measured value based on such standards.) Ra: 0.3 to 0.6 μm surface roughness is obtained. _Even when a coated cutting tip in which the surface of the ₂ O ₃ —ZrO ₂ layer was smoothed to a surface roughness of Ra: 0.3 to 0.6 μm by wet blasting, the cutting speed was 350 m / min. High-speed cutting that exceeds the limit cannot effectively suppress chipping at the cutting edge.

(B) On the other hand, as shown in the schematic perspective view of FIG. 2, the rake face including the cutting edge ridge portion of the Al ₂ O ₃ —ZrO ₂ layer constituting the upper layer of the hard coating layer in the conventional coated cutting tip and A titanium nitride (hereinafter referred to as TiN) layer is formed on the entire flank surface by using a normal chemical vapor deposition apparatus under normal conditions, for example, conditions shown in Table 3 and an average layer thickness of 0.5 to 5 μm. In the state of vapor deposition,
When a polishing liquid containing 15 to 60% by mass of Al ₂ O ₃ fine particles as a spraying abrasive in a ratio to the total amount of water is sprayed by wet blasting as in (a) above, the TiN layer ( Hereinafter, the TiN abrasive layer is pulverized and pulverized by the Al ₂ O ₃ fine particles, becomes TiN fine particles and acts as an abrasive in the presence of the Al ₂ O ₃ fine particles, and constitutes the upper layer of the hard coating layer to become polishing the surface of the _{Al 2 O} 3 -ZrO 2 layers, the surface of the _{Al 2 O} 3 -ZrO 2 layer after the results polishing, Ra: smoothed to a surface roughness of not more than 0.2μm When high-speed cutting is performed using a coated cutting tip in which the surface of the upper layer Al ₂ O ₃ —ZrO ₂ layer is smoothed to a surface roughness of Ra: 0.2 μm or less 350 m / min. Chipping at the cutting edge is prevented even at a cutting speed exceeding 1, and the hard coating layer exhibits excellent wear resistance over a long period of time.

(C) As described above, the cutting speed is 350 m / min. In high-speed cutting that exceeds 1, the load applied to the cutting edge of the coated cutting tip becomes extremely high. Especially in the case of milling, when attaching the coated cutting tip to the tool body, the clamping force is extremely high. As a result, not only the compressive stress on the hard coating layer of the clamp piece abutting portion of the coated cutting tip is extremely high, but also the clamp piece abutting portion during cutting is correspondingly applied. In particular, the mechanical vibration in the Al ₂ O ₃ —ZrO ₂ layer constituting the upper layer is combined with the fact that the Vickers hardness (Hv) has a high hardness of about 2400, Cracks are likely to occur in this, and this causes peeling and chipping in the hard coating layer. As shown in the schematic perspective view of FIG. In Toburasuto, without polishing the clamping piece abutment and keep the state of leaving the TiN abrasive layer of this portion, the TiN abrasive layer as compared with the Al ₂ O ₃ -ZrO _2, and the relative In addition to having a very low Hv: about 1950 hardness and high strength, as shown in a schematic perspective view in FIG. It acts as a buffer layer with a high clamping force. As a result, the compressive stress on the Al ₂ O ₃ —ZrO ₂ layer is remarkably relieved, and the strong mechanical vibration generated during cutting is transmitted to the clamp piece. It acts also as a seismic layer that absorbs and mitigates, thereby mitigating the seismic attack by the clamp piece against the Al ₂ O ₃ —ZrO ₂ layer, so that the Al ₂ O ₃ The generation of cracks that cause peeling and chipping in the -ZrO ₂ layer is prevented.

The research results shown in (a) to (c) above were obtained.

The present invention has been made based on the above research results, and the entire rake face and flank face including the cutting edge ridge line portion of the chip base composed of the WC-based cemented carbide or TiCN-based cermet,
As a lower layer, a Ti compound layer composed of one or more of a TiC layer, a TiN layer, a TiCN layer, a TiCO layer, and a TiCNO layer and having an overall average layer thickness of 3 to 20 μm,
As an upper layer, it has an average layer thickness of 1 to 15 μm, has a two-phase mixed oxide structure of aluminum oxide and zirconium oxide in the state of chemical vapor deposition, and the zirconium oxide is converted into a content ratio of Zr. The two-phase mixed oxide layer of aluminum oxide and zirconium oxide (Al ₂ O ₃ —ZrO) having a ratio (atomic ratio) to the total amount of Al and Zr contained in the layer of 0.01 to 0.20. ₂ layers),
In a coated cutting tip that is formed by vapor deposition of a hard coating layer composed of and attached to a tool body by clamping with a clamp piece,
A TiN abrasive layer having an average layer thickness of 0.5 to 5 μm over the entire surface of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) of aluminum oxide and zirconium oxide, which is the upper layer of the hard coating layer. In the state of vapor deposition,
In wet blasting, as a spraying abrasive, a polishing liquid containing 15 to 60% by mass of Al ₂ O ₃ fine particles in a proportion of the total amount with water is sprayed,

In the coexistence of pulverized TiN fine particles by wet blasting of the TiN abrasive layer and Al ₂ O ₃ fine particles as a spray abrasive, the hard coating layer is left with the abrasive layer on the abutting surface portion of the clamp piece remaining. The surface of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) constituting the upper layer is polished, and the surface roughness of the rake face and the flank face including the cutting edge ridge line portion is compliant with JIS / B0601. -Measured based on 1994, Ra: 0.2 μm or less, characterized by a hard-coated layer with a cermet cutting throwaway tip (coated cutting tip) made of surface-coated cermet that exhibits excellent chipping resistance in high-speed cutting It is what has.

The reason why the numerical values of the hard coating layer and the TiN abrasive layer of the coated cutting chip of the present invention and the Al ₂ O ₃ fine particles of the polishing liquid used in wet blasting are limited as described above will be described below.
(A) Hard coating layer (a-1) Ti compound layer of the lower layer The Ti compound layer exists as a lower layer of the two-phase mixed oxide layer, and the high temperature strength of the hard coating layer by the excellent high temperature strength that it has. In addition to contributing to the improvement, it has a function of firmly adhering to both the chip base and the two-phase mixed oxide layer, thereby improving the adhesion of the hard coating layer to the chip base, but the overall average layer thickness is less than 3 μm However, when the above-mentioned action cannot be fully exhibited, and the overall average layer thickness exceeds 20 μm, it becomes easy to cause thermoplastic deformation particularly in high-speed cutting accompanied by high heat generation, which is a cause of uneven wear. Therefore, the total average layer thickness was determined to be 3 to 20 μm.

(A-2) Two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) as an upper layer

The upper layer composed of a two-phase mixed oxide layer of aluminum oxide and zirconium oxide (Al ₂ O ₃ —ZrO ₂ layer) has excellent high temperature hardness and heat resistance due to its Al component, and also excellent due to its Zr component. High-temperature strength contributes to improving the cutting performance (chipping resistance, wear resistance) of the coated cutting tip, but the content ratio of zirconium oxide in the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) is In terms of the content ratio of Zr, the ratio of the total amount of Al and Zr contained in the layer (= Zr / (Al + Zr)) in the range of 0.01 to 0.20 (however, atomic ratio) Shall be. When this value indicating the content ratio of zirconium oxide in the Al ₂ O ₃ —ZrO ₂ layer is less than 0.01, the effect of improving the high-temperature strength of the upper layer is small, whereas when this value exceeds 0.20 The relative decrease in the amount of aluminum oxide in the upper layer causes a decrease in high-temperature hardness and heat resistance. As a result, there is a tendency for wear resistance to deteriorate, so a two-phase mixed oxide layer (Al ₂ O ₃ − The content ratio of zirconium oxide in the ZrO ₂ layer) (the value of Zr / (Al + Zr) converted in terms of atomic ratio) is set to a value in the range of 0.01 to 0.20 as described above.
Further, if the average layer thickness is less than 1 μm, the desired excellent cutting performance cannot be exhibited over a long period of time. On the other hand, if the average layer thickness exceeds 15 μm, chipping is likely to occur. Therefore, the average layer thickness was determined to be 1 to 15 μm.

(B) TiN abrasive layer As described above, TiN abrasive layer during wet blasting, the Al ₂ O ₃ fine formulated as injection abrasive in the polishing liquid milled micronized, the Al ₂ O ₃ becomes TiN fine The surface of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) that acts as an abrasive in the presence of fine particles and constitutes the upper layer of the hard coating layer is polished. If the thickness is less than 0.5 μm, the ratio of the pulverized TiN fine particles at the time of wet blasting is too small to fully exhibit the polishing function, while if the average layer thickness exceeds 5 μm, the polishing liquid contains The balance with the Al ₂ O ₃ fine particles blended as the blasting abrasive is lost and becomes relatively large. In this case as well, the polishing function rapidly decreases, and in both cases the two-phase mixed oxide layer ( Al ₂ O ₃ The surface of the ZrO ₂ layer) Ra: because it can not be polished to a surface roughness of less than 0.2 [mu] m, determined the average layer thickness and 0.5 to 5 [mu] m.

(C) The _Al 2 _{O 3} fine of _Al 2 _{O 3} fine fraction polishing liquid of the polishing liquid, while coexisting with pulverized TiN fine of TiN abrasive layer during wet blasting, two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) has an action of polishing the surface, but the polishing function is drastically reduced even if the proportion of the total amount with water is less than 15% by mass or exceeds 60% by mass. Therefore, the ratio was determined to be 15 to 60% by mass.

The coated cutting tip of the present invention includes a rake face and a relief including a cutting edge ridge line portion of a two-phase mixed oxide layer of aluminum oxide and zirconium oxide (Al ₂ O ₃ —ZrO ₂ layer) constituting the upper layer of the hard coating layer. The surface is polished to a surface roughness of Ra: 0.2 μm or less, and the abrasive layer present on the clamp piece abutting surface portion is indispensable for high-speed cutting when attaching the coated cutting tip to the tool body. In addition to acting as a buffer layer for clamping force, it acts as an anti-vibration mechanism for strong mechanical vibrations that occur during cutting, so the compressive stress on the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) is significantly relaxed, and vibration attack by the clamp piece becomes extremely small, Ya peeling in a result the two-phase mixed oxide layer (Al ₂ O ₃ -ZrO ₂ layers) What it coupled with the cracking causing mappings generation is to be prevented, the cutting of various kinds of steel and cast iron, cutting speed 350 meters / min. Even when used for high-speed operation exceeding the above, excellent chipping resistance is exhibited, and the service life can be further extended.

  Next, the coated cutting tip of the present invention will be specifically described with reference to examples.

WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder, and Co powder all having an average particle diameter of 1 to 3 μm are prepared as raw material powders. These raw material powders were blended into the composition shown in Table 1, added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and pressed into a green compact with a predetermined shape at a pressure of 98 MPa. The green compact was vacuum sintered at a predetermined temperature in the range of 1370 to 1470 ° C. for 1 hour in a vacuum of 5 Pa. After sintering, the cutting edge portion was R: 0.07 mm honing By processing, chip bases A to F made of a WC-based cemented carbide having a throwaway tip shape specified in ISO · CNMN120408 were manufactured.

In addition, as raw material powders, TiCN (mass ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC powder, all having an average particle diameter of 0.5 to 2 μm. Co powder and Ni powder are prepared, and these raw material powders are blended in the blending composition shown in Table 2, wet mixed by a ball mill for 24 hours, dried, and pressed into a compact at a pressure of 98 MPa. The green compact was sintered in a nitrogen atmosphere of 1.3 kPa at a temperature of 1540 ° C. for 1 hour, and after the sintering, the cutting edge portion was subjected to a honing process of R: 0.07 mm. Chip bases a to f made of TiCN base cermet having standard / CNMN12041 chip shape were formed.

Next, each of these chip bases A to F and chip bases a to f is charged into a normal chemical vapor deposition apparatus,
First, Table 3 (l-TiCN in Table 3 indicates the conditions for forming a TiCN layer having a vertically grown crystal structure described in JP-A No. 6-8010, and other than that, a normal granular crystal structure is shown. Hard coating of the Ti compound layer and the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) having the target layer thickness shown in Table 6 under the conditions shown in Table 4 Vapor deposition as the lower and upper layers of the layer (see Figure 4)
Next, a TiN abrasive material layer was formed by vapor deposition with a target layer thickness also shown in Table 6 under the TiN layer formation conditions shown in Table 3 (see FIG. 2).
Subsequently, the coated cutting tip for forming the TiN abrasive layer is subjected to wet blasting under the blasting conditions shown in Table 5 and in the combinations shown in Table 6, and the TiN abrasive layer is applied to the clamp piece contact surface portion. The rake face and flank face including the cutting edge ridge line portion of the upper layer composed of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) in the presence of the surface roughness are also shown in Table 6. The coated cutting chips 1 to 13 of the present invention were each manufactured by polishing (see FIG. 1).

Further, for comparison purposes, as shown in Table 7, without forming the TiN abrasive layer, the wet blasting of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) of the hard coating layer was performed. Conventionally coated cutting chips 1 to 13 were produced under the same conditions except that they were directly applied to the surface.
Table 7 shows the surface roughness after wet blasting of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) constituting the hard coating layer of the conventional coated cutting chips 1 to 13 obtained as a result.

  In addition, the composition of the hard coating layer and the abrasive layer of the above-described coated cutting chips 1 to 13 of the present invention, and the composition of the hard coating layer of the conventional coated cutting chips 1 to 13 are each measured with an Auger spectroscopic analyzer at the center in the thickness direction. When measured, all showed substantially the same composition as the target composition, and when the thickness of the same constituent layer was measured using a scanning electron microscope (longitudinal section measurement), both were substantially the same as the target layer thickness. The same average layer thickness (average value of 5-point measurement) was shown.

Next, as for the various coated cutting tips of the present invention coated cutting tips 1 to 13 and the conventional coated cutting tips 1 to 13, respectively, as shown in FIGS. 3 and 5, each is a tool steel tool (tool body). In a state where it is attached to the tip of the shank by clamping with a clamp screw of the clamp piece,
Work material: JIS · SCM420 lengthwise equal four round grooved round bars,
Cutting speed: 400 m / min,
Cutting depth: 2.5 mm,
Feed: 0.35 mm / rev,
Cutting time: 7 minutes,
Dry interrupted high-speed cutting test of alloy steel under the above conditions (referred to as cutting condition A) (normal cutting speed is 200 m / min),
Work material: JIS / S50C lengthwise equal 4 round bars with vertical grooves,
Cutting speed: 430 m / min,
Cutting depth: 2.0 mm,
Feed: 0.4 mm / rev,
Cutting time: 8 minutes,
Dry intermittent high speed cutting test (normal cutting speed is 200 m / min) of carbon steel under the above conditions (referred to as cutting conditions B),
Work material: JIS / FC350 round bar,
Cutting speed: 590 m / min,
Cutting depth: 2.0 mm,
Feed: 0.4 mm / rev,
Cutting time: 10 minutes,
A dry continuous high-speed cutting test (normal cutting speed is 250 m / min) of normal cast iron under the above conditions (referred to as cutting condition C), and the flank wear width of the cutting edge was measured in any cutting test. The measurement results are shown in Table 8.

From the results shown in Tables 6 to 8, the coated cutting tips 1 to 13 of the present invention are each a cutting edge of a two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) constituting the upper layer of the hard coating layer. The rake face and flank face including the ridge line part are polished to a surface roughness of Ra: 0.2 μm or less, and the TiN abrasive layer present on the clamp piece abutting surface part is attached to the tool main body with the coated cutting tip. At this time, it acts as a buffer layer with a high clamping force, which is indispensable in high-speed cutting processing exceeding 350 m / min, and also acts as a vibration-proof layer for strong mechanical vibration generated during cutting processing. The compressive stress on the material layer (Al ₂ O ₃ —ZrO ₂ layer) is remarkably relieved and the vibration attack by the clamp piece is extremely small. As a result, the two-phase mixed oxide layer (Al ₂ O ₃ -ZrO ₂ layer) is prevented from cracking, which causes peeling and chipping, exhibits excellent chipping resistance in high-speed cutting of steel and cast iron, and exhibits excellent cutting performance over a long period of time. In contrast, conventional coated cutting in which the surface roughness of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) constituting the upper layer of the hard coating layer is Ra: 0.3 to 0.6 μm In each of the chips 1 to 13, the high-speed cutting process exceeding 350 m / min is coupled with the fact that a high clamping force is required for tool attachment, and the two-phase mixed oxide layer (Al ₂ O ₃ − It is clear that chipping occurs in the ZrO ₂ layer) and the service life is reached in a relatively short time.

  As described above, the coated cutting tip of the present invention can be used not only for continuous cutting and intermittent cutting under normal conditions such as various steels and cast iron, but also when cutting is performed at a high speed exceeding 350 m / min. Because it shows excellent chipping resistance and exhibits excellent cutting performance over a long period of time, it can sufficiently satisfy the high performance of cutting equipment, labor saving and energy saving of cutting work, and further cost reduction. Is.

It is a schematic perspective view of this invention coating cutting tip shown notching a part of hard coating layer. It is a schematic perspective view of the coated cutting tip of TiN abrasive material layer deposition formation shown by cutting out a part of the abrasive material layer. It is a schematic perspective view which shows the attachment aspect to the tool main body of this invention coated cutting tip. It is a schematic perspective view of the conventional coated cutting tip shown by cutting out a part of a hard coating layer. It is a schematic perspective view which shows the attachment aspect to the tool main body of the conventional coated cutting tip.

Claims (1)

It is composed of tungsten carbide base cemented carbide or titanium carbonitride base cermet, and on the entire rake face and flank face including the cutting edge ridge line part of the chip base,
The lower layer is composed of one or more of a titanium carbide layer, a titanium nitride layer, a titanium carbonitride layer, a titanium carbonate layer, and a titanium carbonitride oxide layer, and has an overall average layer thickness of 3 to 20 μm. Having a Ti compound layer,

As an upper layer, it has an average layer thickness of 1 to 15 μm, has a two-phase mixed oxide structure of aluminum oxide and zirconium oxide in the state of chemical vapor deposition, and the zirconium oxide is converted into a content ratio of Zr Then, the ratio (atomic ratio) of the total amount of Al and Zr contained in the layer is 0.01 to 0.20, and the two-phase mixed oxide layer of aluminum oxide and zirconium oxide (Al ₂ O ₃ -ZrO ₂ layer),

In a cutting throwaway tip made of cermet without a hole, which is formed by vapor-depositing a hard coating layer composed of and attached to a tool body by clamping with a clamp piece so as to be replaceable,
A titanium nitride layer having an average layer thickness of 0.5 to 5 μm is formed on the entire surface of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) of aluminum oxide and zirconium oxide, which is the upper layer of the hard coating layer. In a state where the configured abrasive layer is deposited and formed,
In wet blasting, as a spraying abrasive, a polishing liquid containing 15 to 60% by mass of aluminum oxide fine particles in a proportion of the total amount with water is sprayed,
In the presence of the ground titanium nitride fine particles by wet blasting of the abrasive layer and the aluminum oxide fine particles as the spray abrasive, the abrasive layer of the abutting surface portion of the clamp piece is left, and the hard coating layer The surface of the two-phase mixed oxide layer (Al ₂ O ₃ —ZrO ₂ layer) of aluminum oxide and zirconium oxide constituting the upper layer is polished to reduce the surface roughness of the rake face and the flank face including the cutting edge ridge line portion. The measurement based on JIS / B0601-1994, Ra: 0.2 μm or less, the hard coating layer is made of surface-coated cermet without hole that exhibits excellent chipping resistance in high-speed cutting. Slow away tip.

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