JP6344011B2 - Cutting tools - Google Patents

Description

  The present invention relates to a cutting tool in which a hard coating film is formed on a tool substrate that is a cBN sintered body.

Conventionally, a cutting tool in which a hard coating film is formed on the surface of a tool base made of a cBN (cubic boron nitride) sintered body to improve wear resistance is known.
cBN has characteristics suitable for cutting tools such as high hardness, high heat resistance, and low reactivity with ferrous metals. For this reason, according to the cutting tool provided with the tool base material of cBN sintered compact, effects, such as improvement of processing efficiency and reduction of production cost, are obtained, for example in processing of iron system difficult-to-cut material.

For example, the following Patent Documents 1 to 3 disclose this type of cutting tool.
Patent Document 1 discloses a tool base material containing a high content of cBN.
Patent Document 2 discloses a cutting tool in which an intermediate layer made of metal (Cr, V, Zr) is provided between a cBN substrate and a hard coating film. That is, cBN is an insulating substance and is difficult to be charged, and it is difficult to ensure sufficient adhesion strength with the hard coating film. Therefore, a metal intermediate layer is provided for the purpose of improving this.
Patent Document 3 discloses a cutting tool in which a stress difference is provided inside a hard coating film. The internal stress (compressive residual stress) of the hard coating film is changed from the surface of the film toward the base material, thereby trying to achieve both wear resistance and toughness.

JP 2008-222485 A European Patent No. 1195542 Japanese Patent No. 4653789

However, the conventional cutting tool has the following problems.
That is, in Patent Document 1, it is difficult to sufficiently obtain the adhesion strength of the hard coating film to the tool substrate. This is because cBN is a non-conductive substance (insulating substance) as described above. Generally, a tool base material made of a cBN sintered body is inferior in adhesion strength of a hard coating film compared to a tool base material made of a cemented carbide. In particular, as the cBN content of the tool substrate increases, the hard coating film is less likely to adhere to the surface of the tool substrate.

  Moreover, in patent document 2, although the intermediate layer which consists of a metal is provided between the tool base material and the hard coating film, since it is inferior to abrasion resistance, a metal is easy to wear. Further, the difference in thermal expansion coefficient between the hard coating film and the metal layer tends to increase, and the hard coating film easily peels off.

  In Patent Document 3, it is difficult to stably form a hard coating film. That is, in order to change the internal stress of the hard coating film from the surface of the film toward the substrate side, it is necessary to change film forming conditions such as a bias voltage during the film formation of the hard coating film. However, film formation while changing the film formation conditions may cause crystal growth and crystallinity to be non-uniform (influence of control of the grain size of the polycrystalline film, resulting in mismatch). For this reason, the performance of the hard coating film is not stable, and the quality of the film tends to become unstable.

  The present invention has been made in view of such circumstances, and can improve the adhesion strength of the hard coating film to the tool substrate without providing an intermediate layer made of metal, and the quality of the hard coating film. It aims at providing the cutting tool which can stabilize.

In order to solve such problems and achieve the above object, the present invention proposes the following means.
That is, the cutting tool of the present invention includes a tool base material that is a cBN sintered body, an adhesion reinforcing film formed by being laminated on the surface of the tool base material, and a hard coating film. The hard coating film is formed on the surface of the adhesion reinforcing film, and is formed of a nitride containing at least Ti or Al, and is formed on the surface of the tool base material. The adhesion reinforcing film and the hard coating film are formed one layer at a time, or are formed by alternately laminating a plurality of layers, and the adhesion reinforcing film is set to have a constant compressive residual stress. The compressive residual stress is set constant, and the compressive residual stress of the hard coating film is higher than the compressive residual stress of the adhesion strengthening film.

According to the cutting tool of the present invention, since the compressive residual stress of the hard coating film is higher than the compressive residual stress of the adhesion reinforcing film, the following effects can be obtained.
That is, the wear resistance of the tool is improved by the hard coating film having a high compressive residual stress. In addition, since the adhesion strengthening film is set to have a low compressive residual stress, the effect of improving the adhesion strength of the hard coating film to the tool substrate can be obtained. Furthermore, the adhesion enhancing film acts as a tough buffer layer between the tool substrate and the hard coating film. Therefore, peeling of the hard coating film is remarkably prevented.

  Further, the adhesion reinforcing film is not a so-called metal layer while exhibiting the above-described effect of improving the adhesion strength. Therefore, the wear resistance of the adhesion reinforcing film itself is ensured. Moreover, it is easy to suppress the difference in thermal expansion coefficient between the adhesion reinforcing film and the hard coating film, and the effect of preventing the peeling of the hard coating film can be stably obtained.

In the present invention, when the hard coating film is formed, the compressive residual stress inside the film can be set constant. That is, the film formation can be performed without changing the film formation conditions such as the bias voltage during the formation of the hard coating film. For this reason, the crystal growth and crystallinity of the hard coating film can be made uniform, and the particle size can be controlled with high accuracy.
Therefore, a product (cutting tool) with high performance and long tool life and stable quality can be obtained continuously (stably).

  As described above, according to the present invention, the adhesion strength of the hard coating film to the tool substrate can be improved and the quality of the hard coating film can be stabilized without providing an intermediate layer made of metal.

The front Symbol hard coating is compressive residual stress Ru is set to a constant.

When forming the hard substance coating film, it is not necessary to change the film formation conditions of the bias voltage or the like. Therefore, the quality of the hard coating film can be stabilized.

The front Symbol adhesion reinforcing layer is compressive residual stress Ru is set to a constant.

When the formation of the attached adhesive reinforced membrane, there is no need to change the conditions for forming the bias voltage, and the like. Therefore, the quality of the adhesion enhancing film can be stabilized.

  In the cutting tool of the present invention, the hard coating film and the adhesion reinforcing film may be made of the same material component.

  In this case, since it becomes easy to make the film-forming process of a hard coating film and an adhesion reinforcement film common, it becomes possible to form a film efficiently at low cost.

  In the cutting tool of the present invention, the hard coating film and the adhesion reinforcing film may be made of different material components.

In this case, since various materials can be combined, the degree of freedom in forming the hard coating film and the adhesion reinforcing film is increased.
In the cutting tool of the present invention, the adhesion reinforcing film may be any one of (Al _1-X Ti _X ) N (X value is an atomic ratio), TiSiN, and AlCrN.
Further, in the cutting tool of the present invention, the hard coating _{film, (Al 1-Y-Z} Ti Y Si Z) N (Y value, Z value atom _{ratio), (Al 1-X Ti} X) N ( The X value may be any of atomic ratio), TiSiN, and AlCrN.

  According to the cutting tool of the present invention, the adhesion strength of the hard coating film to the tool substrate can be improved and the quality of the hard coating film can be stabilized without providing an intermediate layer made of metal.

It is a longitudinal cross-sectional view which shows the principal part of the cutting tool which concerns on one Embodiment of this invention. It is a graph which shows the result of the peeling resistance confirmation test of the hard coating body in the Example of this invention, and the conventional comparative example. It is a graph which shows transition (result of flank wear amount confirmation test A) of the wear amount of a flank in the Example of this invention, and the conventional comparative example. It is a graph which shows transition (result of flank wear amount confirmation test B) of the wear amount of a flank in the Example of this invention and the conventional comparative example.

Hereinafter, a cutting tool 1 according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a main part (near the hard covering 3) of a cutting tool 1 according to an embodiment of the present invention.
The cutting tool 1 includes, for example, a drill that drills a workpiece made of a metal material such as carbon steel, an end mill that performs face machining or shoulder machining, and a bit that performs circumferential machining or end machining. Etc. Alternatively, for example, a cutting insert (cutting tool 1) that is detachably attached to a holder in a cutting edge exchangeable cutting tool such as a milling cutter may be used.
The cutting tool 1 is a surface-coated cutting tool in which a surface coating is applied to at least a contact portion of the tool base 2 with a work material (that is, a cutting edge or a blade portion including the cutting edge region).

  As shown in FIG. 1, a cutting tool 1 includes a tool base 2 that is a cBN (cubic boron nitride) sintered body, and a hard covering 3 formed on a surface 2 a of the tool base 2. .

  The tool base 2 is made of a cBN sintered body having 20% by volume or more of cBN. The tool base 2 is made of ceramic and metal binder.

  The hard covering 3 is formed by laminating an adhesion reinforcing film 11 and a hard heat-resistant film (hard coating film) 12. The hard covering 3 is formed by forming an adhesion reinforcing film 11 and a hard heat-resistant film 12 on the surface 2a of the tool base 2 one by one.

The adhesion reinforcing film 11 is directly formed on the surface 2a of the tool base 2 and has an average film thickness of 0.5 to 10 μm, for example. The adhesion reinforcing film 11 is provided between the tool base 2 and the hard heat resistant coating 12.
The adhesion reinforcing film 11 is made of any one of carbide, nitride, carbonitride, and oxide containing at least Ti or Al. The adhesion reinforcing film 11 is not a so-called metal layer. Specifically, the adhesion reinforcing film 11 is made of, for example, Al ₆₀ Ti ₄₀ N, Ti ₅₀ Al ₅₀ N, or the like.
The adhesion strengthening film 11 may be, for example, (Al _1-X Ti _X ) N (X value is an atomic ratio) other than the above, TiSiN, AlCrN, or the like.

The hard heat-resistant film (hard coating film) 12 is formed on the surface of the adhesion reinforcing film 11 and has an average film thickness of, for example, 0.5 to 10 μm. The hard heat-resistant coating 12 is exposed to the outside of the cutting tool 1 and contacts the work material.
The hard heat-resistant film 12 is made of any of carbide, nitride, carbonitride, and oxide containing at least Ti or Al. The hard heat resistant coating 12 is not a so-called metal layer. Specifically, the hard heat resistant coating 12 is made of, for example, Al ₅₄ Ti ₄₁ Si ₅ N, Ti ₅₀ Al ₅₀ N, or the like.
Hard refractory coating 12, for example, other than the above _{(Al 1-Y-Z Ti} Y Si Z) N (Y value, Z value atom _{ratio), (Al 1-X Ti} X) N (X value atomic ratio ), TiSiN, AlCrN, or the like.

  The hard heat resistant coating 12 and the adhesion reinforcing film 11 may be made of the same material component. Alternatively, the hard heat resistant coating 12 and the adhesion reinforcing film 11 may be made of different material components.

  Both the adhesion reinforcing film 11 and the hard heat-resistant film 12 are formed so that compressive stress remains inside the film. The compressive residual stress (internal stress) of the adhesion strengthening film 11 and the hard heat resistant coating 12 is set to have different magnitudes.

  The compressive residual stress of the hard heat resistant coating 12 is higher than the compressive residual stress of the adhesion strengthening film 11. Specifically, the hard heat resistant coating 12 against the compressive residual stress of the adhesion strengthening film 11 so that the compressive residual stress of the hard heat resistant coating 12 and the compression residual stress of the adhesion reinforcing film 11 have a stress difference of 1 GPa or more. The compressive residual stress of is set high.

The compressive residual stress of the adhesion strengthening film 11 and the compressive residual stress of the hard heat resistant coating 12 are set to be constant.
In other words, the compressive residual stresses of the adhesion reinforcing film 11 and the hard heat resistant coating 12 do not change in the film thickness direction (the direction from the surface 2a of the tool base 2 toward the surface of the hard heat resistant coating 12). That is, the compressive residual stress does not gradually change in the film thickness direction.
The adhesion strengthening film 11 and the hard heat-resistant film 12 are formed so that the compressive residual stress is constant, so that they are stable films. In addition, since the film formation is facilitated, the film quality is improved.

The hard covering 3 is formed on the surface 2a of the tool base 2 by the following procedure, for example.
Using the arc ion plating apparatus, the tool base 2 is disposed in the furnace, and the furnace is heated to a temperature of about 500 to 600 ° C. by heating means such as a heater.
Then, arc discharge is generated under the condition of current: 100 to 200 A between the cathode electrode (evaporation source) on which the Al—Ti alloy having a predetermined composition is set and the anode electrode. At the same time, nitrogen gas (N ₂ ) is introduced as a reaction gas into the furnace to form a reaction atmosphere at a pressure of 2.5 to 10.0 Pa, and a bias voltage of −10 to −50 V is applied to the tool base 2. The bias voltage is not changed during film formation.
As a result, the adhesion reinforcing film 11 made of (Al, Ti) N is deposited on the surface 2 a of the tool base 2 by vapor deposition.

Next, arc discharge is generated under the condition of current: 100 to 200 A between the cathode electrode (evaporation source) on which the Al—Ti alloy having a predetermined composition is set and the anode electrode. At the same time, nitrogen gas (N ₂ ) is introduced as a reaction gas into the furnace to form a reaction atmosphere at a pressure of 2.5 to 10.0 Pa, and a bias voltage of −30 to −100 V is applied to the tool base 2. The other conditions are the same as the film formation conditions for the adhesion reinforcing film 11 described above. The bias voltage is not changed during film formation.
As a result, a hard heat-resistant coating 12 made of (Al, Ti) N is vapor-deposited on the surface of the adhesion reinforcing film 11.

  In addition, about the average film thickness of the hard heat resistant film 12 and the adhesion reinforcement film | membrane 11, it is controllable by the operating time etc. of an apparatus. For example, the average film thickness of the hard heat resistant coating 12 and the adhesion reinforcing film 11 can be set to 1 μm. In this case, the film thickness of the hard cover 3 is 2 μm, and the average film thickness of the hard heat-resistant film 12 and the average film thickness of the adhesion reinforcing film 11 are substantially the same. Alternatively, the average film thickness of the hard heat resistant coating 12 is 2.0 μm, the average film thickness of the adhesion reinforcing film 11 is 0.5 μm, and the average film thickness of the hard heat resistant coating 12 is larger than the average film thickness of the adhesion reinforcing film 11. It may be made to become.

As described above, the cutting tool 1 is formed on the tool base 2 that is a cBN sintered body, the adhesion reinforcing film 11 that is formed on the surface 2 a of the tool base 2, and the surface of the adhesion reinforcing film 11. Hard heat-resistant coating 12. The hard heat resistant film 12 and the adhesion reinforcing film 11 are each made of any one of carbide, nitride, carbonitride, and oxide containing at least Ti or Al.
The compressive residual stress of the hard heat resistant coating 12 is set to be higher than the compressive residual stress of the adhesion strengthening film 11.

  For this reason, according to the cutting tool 1 of the present embodiment, the wear resistance of the tool is improved by the hard heat resistant coating 12 having a high compressive residual stress. Moreover, since the adhesion reinforcement film | membrane 11 is set low in a compressive residual stress, the effect of improving the adhesion strength of the hard heat-resistant coating film 12 with respect to the tool base material 2 is acquired. Further, the adhesion reinforcing film 11 acts as a tough buffer layer between the tool base 2 and the hard heat resistant coating 12. Therefore, peeling of the hard heat resistant coating 12 is remarkably prevented.

  Further, the adhesion reinforcing film 11 is not a so-called metal layer while exhibiting the above-described effect of improving the adhesion strength. Therefore, the wear resistance of the adhesion reinforcing film 11 itself is ensured. Moreover, it is easy to suppress the difference in thermal expansion coefficient between the adhesion reinforcing film 11 and the hard heat resistant coating 12, and the effect of preventing the separation of the hard heat resistant coating 12 can be stably obtained.

  As described above, according to the present embodiment, the adhesion strength of the hard heat-resistant coating 12 to the tool substrate 2 can be improved without providing a metal intermediate layer, and the quality of the hard heat-resistant coating 12 (and thus the hard heat-resistant coating 12 and The quality of the entire hard covering 3 including the adhesion reinforcing film 11) can be remarkably stabilized.

In the present embodiment, when the hard heat resistant coating 12 and the adhesion reinforcing film 11 are formed, the compressive residual stress inside each film is set to be constant. In other words, during the formation of each of the hard heat resistant coating 12 and the adhesion reinforcing film 11, the film is formed without changing the film forming conditions such as the bias voltage. For this reason, the crystal growth and crystallinity of the hard heat resistant coating 12 and the adhesion reinforcing film 11 can be made uniform, and the particle size can be controlled with high accuracy. That is, the quality of the hard heat resistant coating 12 and the adhesion reinforcing film 11 can be stabilized.
Therefore, a product (cutting tool 1) with high performance and long tool life and stable quality can be obtained continuously (stably).

Further, when the hard heat resistant coating 12 and the adhesion reinforcing film 11 are made of the same material component, it is easy to share the film forming process of the hard heat resistant coating 12 and the adhesion reinforcing film 11, so that the film is efficiently formed at low cost. It becomes possible.
Further, when the hard heat resistant coating 12 and the adhesion reinforcing film 11 are made of different material components, various materials can be combined, so that the degree of freedom in forming the hard heat resistant coating 12 and the adhesion reinforcing film 11 is increased. .

In addition, the above-mentioned effect reliably suppresses wear and peeling of the hard covering 3 not only when carbon steel is used as a work material but also when a material other than carbon steel is used as the work material. Can extend tool life.
For example, when the margin part of a drill (cutting tool 1) is covered with the hard covering 3, when using a material other than carbon steel as a work material, when using carbon steel as a work material, However, margin wear can be remarkably suppressed, and the tool life is extended.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the above-described embodiment, the hard cover 3 has been described with respect to the configuration in which the hard heat-resistant film 12 and the adhesion reinforcing film 11 are laminated one by one. However, the present invention is not limited to this.
That is, the hard covering 3 may be formed by alternately laminating a plurality of hard heat-resistant coatings 12 and adhesion reinforcing films 11.

  In addition to the hard cover 3, a colored layer (decorative layer) for appearance decoration having a layer thickness thinner than that of the hard heat-resistant film 12 and the adhesion reinforcing film 11 may be provided on the surface of the hard cover 3.

Further, the difference in film thickness and internal stress (compressive residual stress) between the hard heat resistant coating 12 and the adhesion reinforcing film 11 is not limited to those described in the above-described embodiment, and can be changed as appropriate.
In addition, the material components of the hard heat resistant coating 12 and the adhesion reinforcing film 11 are not limited to the example described in the above embodiment.

  In addition, in the range which does not deviate from the meaning of this invention, you may combine each structure (component) demonstrated by the above-mentioned embodiment, a modified example, a note, etc., addition of a structure, omission, substitution, others It can be changed. Further, the present invention is not limited by the above-described embodiments, and is limited only by the scope of the claims.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to this embodiment.

[Peeling resistance confirmation test]
As Examples 1 to 3 of the present invention, a steel member (workpiece) was cut using the cutting tool 1 (bite) of the above-described embodiment. Moreover, as comparative examples 1-5, the steel member was cut on the same conditions as the cutting tool 1 (Examples 1-3) using the following tools.
And the time until peeling occurred in the hard covering 3 (processing time) was compared.

<Cutting tools>
All the tool base materials 2 are the cBN sintered bodies described in the above embodiment. The hard cover 3 is as follows.
[Example 1]
Hard covering 3
Adhesion strengthening film 11: Ti ₅₀ Al ₅₀ N (compressive residual stress: low)
Hard heat-resistant coating 12: Ti ₅₀ Al ₅₀ N (Compressive residual stress: high)
[Example 2]
Hard covering 3
Adhesion strengthening film 11: Al ₆₀ Ti ₄₀ N (compressive residual stress: low)
Hard heat-resistant coating 12: Al ₅₄ Ti ₄₁ Si ₅ N (Compressive residual stress: high)
[Example 3]
Hard covering 3
Adhesion strengthening film 11: Al ₇₀ Cr ₃₀ N (compressive residual stress: low)
Hard heat-resistant coating 12: Ti ₉₅ Si ₅ N (compressive residual stress: high)
[Comparative Example 1]
Hard coating Adhesion strengthening film: None Hard heat-resistant coating: Ti ₅₀ Al ₅₀ N (Compressive residual stress: low)
[Comparative Example 2]
Hard coating Adhesion strengthening film: None Hard heat-resistant coating: Ti ₅₀ Al ₅₀ N (Compressive residual stress: high)
[Comparative Example 3]
Hard coating adhesion strengthening film: Ti ₅₀ Al ₅₀ N (Compressive residual stress: high)
Hard heat-resistant coating: Ti ₅₀ Al ₅₀ N (compressive residual stress: low)
[Comparative Example 4]
Hard coating Adhesion strengthening film: None Hard heat resistant coating: Al ₅₄ Ti ₄₁ Si ₅ N (Compressive residual stress: high)
[Comparative Example 5]
Hard coating Adhesion strengthening film: None Hard heat-resistant coating: Ti ₉₅ Si ₅ N (Compressive residual stress: high)

<Cutting object and cutting conditions>
Work material: SCr420 (Hardness: HRC60)
Cutting speed: 150 m / min
Feed: 0.2mm / rev
Cutting depth: 0.2mm
Cutting form: Dry Cutting time: 20 min
Cutting method: peripheral turning (continuous machining of round bars)

<Result>
FIG. 2 is a graph showing the results of a peel resistance confirmation test of the hard coated body 3 in Examples 1 to 3 and Comparative Examples 1 to 5. The vertical axis of the graph represents time (continuous processing time) until the hard covering 3 is peeled off.

As shown in FIG. 2, in Comparative Examples 1 to 5, peeling occurred in the hard coating when the processing time was about 10 minutes.
On the other hand, in Examples 1-3, peeling does not occur in the hard covering 3 even when the processing time exceeds 16 minutes, and in Examples 1 and 2, even when the processing time reaches 20 minutes, Peeling did not occur in the hard cover 3 and the cutting process could be continued.
Thus, according to the cutting tool 1 (Examples 1-3) of this invention, it turned out that tool life is extended (secured) significantly compared with Comparative Examples 1-5.

[Flank wear amount confirmation test A]
Next, a cutting tool 1 having the same specifications as that of Example 1 of the present invention used in the above-described peel resistance confirmation test is prepared as Example 1 of this test, and Comparative Example 3 described above as a conventional comparative example. The steel parts were cut using the same specifications as the above, and the changes in the amount of wear on the flank were compared.

<Cutting object and cutting conditions>
Work material: SCr420 (Hardness: HRC60)
Cutting speed: 180 m / min
Feed: 0.15mm / rev
Cutting depth: 0.2mm
Cutting form: Dry Cutting time: 30 min
Cutting method: peripheral turning (continuous machining of round bars)

<Result>
The results of this test are shown in the graph of FIG. The vertical axis of the graph represents the amount of wear on the flank. The horizontal axis of the graph represents the cutting time (continuous processing time).

As shown in FIG. 3, in Comparative Example 3, the amount of wear on the flank gradually increases as the machining time increases, and when the machining time reaches 13 minutes, the hard covering peels off and wears on the flank. The amount increased rapidly.
On the other hand, in Example 1, even when the processing time exceeds 15 minutes, exceeds 20 minutes, and further exceeds 30 minutes, the hard covering 3 does not peel off, and the amount of wear on the flank slightly increases. Met. And it was in the state where cutting could be continued further.
Thus, according to the cutting tool 1 (Example 1) of this invention, it turned out that a tool life is extended significantly compared with the comparative example 3. FIG.

[Flank wear amount confirmation test B]
Next, a cutting tool 1 having the same specifications as that of Example 1 of the present invention used in the above-described peel resistance confirmation test is prepared as Example 1 of this test, and Comparative Example 3 described above as a conventional comparative example. The steel parts were cut using the same specifications as the above, and the changes in the amount of wear on the flank were compared.
In this test, unlike the above-described flank wear amount confirmation test A, the work material (round bar) was provided with eight grooves to perform intermittent processing.

<Cutting object and cutting conditions>
Work material: SCM415 (Hardness: HRC60)
Cutting speed: 150 m / min
Feed: 0.2mm / rev
Cutting depth: 0.2mm
Cutting form: Dry Cutting time: 10 min
Cutting method: peripheral turning (intermittent machining of a round bar with 8 grooves)

<Result>
The results of this test are shown in the graph of FIG. The vertical axis of the graph represents the amount of wear on the flank. The horizontal axis of the graph represents the cutting time (intermittent processing time (that is, the time during which cutting is intermittently performed on the outer periphery of the work material)).

As shown in FIG. 4, in Comparative Example 3, the amount of wear on the flank gradually increases as the machining time increases, and when the machining time reaches 6 minutes, the hard covering peels off and wears on the flank. The amount increased rapidly.
On the other hand, in Example 1, even when the processing time exceeded 10 minutes, the hard covering 3 did not peel off, and the amount of wear on the flank was only slightly increased. And it was in the state where cutting could be continued further.
Thus, according to the cutting tool 1 (Example 1) of this invention, it turned out that a tool life is extended significantly compared with the comparative example 3. FIG.

DESCRIPTION OF SYMBOLS 1 Cutting tool 2 Tool base material 3 Hard coating body 11 Adhesion reinforcement film | membrane 12 Hard heat-resistant coating film (hard coating film)

Claims (5)

a tool substrate which is a cBN sintered body;
An adhesion reinforcing film formed on the surface of the tool base material and a hard coating film,
The adhesion reinforcing film is made of a nitride containing at least Ti or Al,
The hard coating film is formed on the surface of the adhesion reinforcing film, and is made of a nitride containing at least Ti or Al,
On the surface of the tool base, the adhesion reinforcing film and the hard coating film are each formed one by one, or are formed by alternately laminating a plurality of layers,
The adhesion reinforcing film is set to have a constant compressive residual stress,
The hard coating film is set to have a constant compressive residual stress,
A cutting tool, wherein the compressive residual stress of the hard coating film is higher than the compressive residual stress of the adhesion reinforcing film. The cutting tool according to claim 1,
The cutting tool, wherein the hard coating film and the adhesion reinforcing film are made of the same material component. The cutting tool according to claim 1 ,
The cutting tool, wherein the hard coating film and the adhesion reinforcing film are made of different material components. The cutting tool according to any one of claims 1 to 3,
The adhesion reinforcing layer _is a cutting tool, characterized in that _{(Al 1-X Ti X)} N (X value atomic ratio), is either TiSiN, and AlCrN. The cutting tool according to any one of claims 1 to 4,
The hard coating film includes (Al _1-YZ Ti _Y Si _Z ) N (Y value, Z value is an atomic ratio), (Al _1-X Ti _X ) N (X value is an atomic ratio), TiSiN, And a cutting tool characterized by being any one of AlCrN.

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