JP2005271106A - Coated cutting tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated cutting tool, preventing the formation of a porous Ti oxide layer due to containing of Ti in a coating film in cutting to prevent the breakage and chipping of a knife edge, further preventing the separation of a coating film, and having favorable wettability. <P>SOLUTION: This coated cutting tool includes: a base material; and a coating film formed on the surface of the base material. The coated cutting tool is characterized in that the coating film is one selected from nitride, carbonic nitride, nitrogen oxide and carbonic nitrogen oxide of (Al<SB>1-x</SB>V<SB>x</SB>) (wherein x is from 0.24 to 0.45 both inclusive). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coated cutting tool, and specifically to a coated cutting tool provided with a coating film having wear resistance.

  Recent trends in cutting tools include zero-emission processing from the viewpoint of global environmental protection, the diversification of work materials such as heat-resistant alloys and Pb-less alloys, and further improvement in machining efficiency. Therefore, the cutting edge temperature tends to become higher due to the fact that the cutting speed and the feeding speed are higher, and the characteristics required for the tool material are becoming stricter.

  In particular, the required characteristics of the tool material include not only the stability of the coating at high temperatures (oxidation resistance and coating adhesion), but also the wear resistance related to the life of the cutting tool, that is, the improvement in hardness and lubrication of the coating at high temperatures. The lubrication characteristics of coatings that change to oils are becoming more important.

For example, according to Patent Document 1 below, nitride containing Ti as a main component, carbonitride, oxynitride and oxycarbonitride containing an appropriate amount of Si, and nitride containing Ti and Al as main components , carbonitride, oxynitride and oxycarbonitride, nitrides of microstructural constituents, such as TiSi-based compound as a main component Ti, carbonitrides, in oxynitride and oxycarbonitride nitride, Si ₃ It is disclosed that when dry high-speed cutting is performed using a cutting tool that is alternately coated with one or more layers such that N ₄ and Si exist as independent phases, the performance of the cutting tool becomes extremely good. According to Patent Document 1, an alumina layer formed by surface oxidation that occurs in cutting work in a conventional TiAlN film functions as an oxidation protective film against inward diffusion of oxygen. The surface alumina layer peels off more easily than the porous Ti oxide layer directly below it, and is not sufficient for the progress of oxidation. However, the TiSi-based film of Patent Document 1 below has extremely high oxidation resistance of the film itself. In addition, a very dense composite oxide of Ti and Si containing Si is formed on the outermost surface, so that the porous Ti oxide layer, which has been a problem in the past, is not formed, resulting in improved performance. It is shown. Furthermore, there is a suggestion of the coating order that it is important to coat the TiSi film directly on the TiAl film.

  However, as a result of studying the coating film, there was a problem that the cutting edge was easily chipped, particularly when used for intermittent cutting. In addition, since the hardness of the coating is high, the internal compression stress of compression accumulated inside becomes high, and there is also a problem that the film peels off with a particularly sharp blade edge. In addition, there is no suggestion or disclosure regarding the lubricity of the coating, which is a problem during dry processing.

From the viewpoint of lubricity, that is, prevention of welding, a coating film covered with an oxide having a melting point of 1000 ° C. or less on the surface, specifically, a compound of titanium, vanadium, and nitrogen, and at least an oxidation on the outermost surface A cutting tool containing vanadium is disclosed in Patent Document 2 below. In order to obtain the same effect, the following Patent Document 3 discloses that (V _u Ti _1-u ) (N _v C _1-v ) where 0.25 ≦ u ≦ 0.75, The coating of 0.6 ≦ v ≦ 1 is disclosed. Again, it is shown that VTiN to which V is added contributes to lubricity and welding resistance.

  However, since the coatings disclosed in Patent Document 2 and Patent Document 3 always contain Ti, a porous Ti oxide layer is formed when the coating is oxidized at a high temperature as described in Patent Document 1 described above. As a result, the coating easily peeled off, which was insufficient for the progress of oxidation.

Therefore, in order to obtain a film having excellent wear resistance and lubricity while maintaining the peelability and chipping property of the film, the present inventors do not include Ti in the film, and the coating film is (Al _{x− 1} V _x ) nitrides, carbonitrides, oxynitrides, and oxycarbonitrides (where x is not less than 0.24 and not more than 0.45), and the internal compressive stress and hardness in the high hardness coating The present inventors have obtained the knowledge that it is effective to change the temperature and have reached the present invention.
Japanese Patent No. 3347687 Japanese Patent No. 3250966 JP 2000-199047 A

  The present invention has been made in order to solve the above-mentioned problems of the prior art, and its purpose is to form a porous Ti oxide layer by containing Ti in the coating film during cutting. An object of the present invention is to provide a coated cutting tool that prevents cracking and chipping of the cutting edge, prevents peeling of the coating film, and has good wettability.

The present invention provides a coated cutting tool comprising a base material and a coating film formed on the surface of the base material, wherein the coating film is a nitride, carbonitride of (Al _x-1 V _x ), Provided is a coated cutting tool characterized in that it is either a nitrided oxide or a carbonitride (where x is not less than 0.24 and not more than 0.45).

  Preferably, at least one of the internal compressive stress and the hardness of the coating film changes continuously or stepwise from the base material to the surface of the coating film.

  Preferably, the internal compressive stress of the coating film increases continuously or stepwise from the base material to the surface of the coating film in a range of −8 GPa to 0 GPa, or the coating film The hardness by the nanoindenter increases continuously or stepwise from the substrate to the surface of the coating film in the range of 18 GPa to 55 GPa.

  Preferably, the internal compressive stress of the coating film decreases continuously or stepwise from the substrate to the surface of the coating film in a range of −8 GPa to 0 GPa, or The hardness by the nanoindenter decreases continuously or stepwise from the substrate side to the surface side of the coating film in the range of 18 GPa to 55 GPa.

  Preferably, the thickness of the coating film is 0.5 μm or more and 15.0 μm or less.

  Preferably, Ti or Cr, Ti nitride, TiAl nitride, or Cr nitride having a thickness of 0.005 μm or more and 5.0 μm or less is attached between the base material and the coating film. Provide as a reinforcement layer.

  Preferably, the crystal structure of the coating film is a cubic crystal.

  Preferably, the base material is a WC-based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, boron nitride sintered body, a base made of aluminum oxide and titanium carbide. One of the materials.

  Preferably, the coated cutting tool of the present invention is used as a drill, end mill, milling and turning cutting edge replaceable tip, metal saw, gear cutting tool, reamer, and tap.

  Preferably, the coating film is coated by physical vapor deposition.

  Preferably, the coating film is coated by an arc type ion plating method or a magnetron sputtering method.

  According to the present invention, it is possible to improve the peel resistance and wear resistance of drills, end mills, milling and turning blade inserts, metal saws, gear cutting tools, reamers, taps, etc. A tool can be provided.

The coated cutting tool of the present invention includes a base material and a coating film formed on the surface of the base material, and the coating film is a nitride (Al _x-1 V _x ), a carbonitride, It is characterized by being either a nitrogen oxide or a carbonitrous oxide. However, x is 0.24 or more and 0.45 or less.

  In particular, the coating film in the coated cutting tool of the present invention is characterized in that it does not contain Ti as a metal component and is mainly composed of Al. Thus, by containing Al as a main component and not containing Ti, porous Ti oxide is not formed even if the surface of the coating film is oxidized during cutting. In addition, the inclusion of Al is preferable because the oxidation resistance is improved, the thermal conductivity is increased, and heat generated during cutting can be released from the tool surface into the atmosphere or through a machine tool. Further, by containing Al, preferable lubricating performance on the surface can be obtained, so that the welding resistance performance is improved, and as a result, the cutting resistance can be reduced and the chip discharge performance can be improved.

In the cutting coated tool of the present invention, in (Al _x-1 V _x ) which is a component constituting the coating film, x is 0.24 or more and 0.45 or less. That is, in the binary system of Al and V, the amount of V is 0.24 or more and 0.45 or less. This is because when X exceeds 0.45 or less than 0.24, the hardness of the coating film decreases, and a problem arises in wear resistance. More preferably, x is 0.3 or more and 0.4 or less. If V is present in the coating film, the surface of the coating film is oxidized in a high temperature environment at the time of cutting. At this time, since the oxide of V has a low melting point, it acts as a lubricant at the time of cutting, and the work material It is preferable because an effect of suppressing the adhesion of can be expected.

  Moreover, it is also preferable in the coating film in the coated cutting tool of the present invention that by adding V in the above range, a cubic Al compound that is a metastable phase at normal temperature and pressure can be formed. For example, taking AlN as a nitride as an example, the estimated lattice constant is usually 4.12Å when the crystal structure of AlN is a hexagonal crystal but a cubic crystal that is a metastable phase. The lattice constant of VN, which is a stable phase of cubic crystals at normal temperature and pressure, is 4.14Å, which is very close to cubic AlN, so that the pulling effect causes AlN to become cubic and have high hardness. Therefore, the crystal structure of the film is preferably cubic.

  In addition, since the coating film in the present invention does not contain Ti, the effect of adhesion resistance is particularly exerted with respect to the machining of a Ti alloy called a difficult-to-cut material, even during machining.

  In the present invention, silicon (Si) or boron (B) may be contained in the coating film in an atomic percent of less than 10%. The presence of Si in the coating film is preferable because the texture of the coating film is refined from a columnar shape to a needle shape and the hardness of the coating film is improved. Further, when B is contained in the film, the mechanism is not known, but it is preferable because a coating film having higher hardness can be obtained. Further, when B is contained in the coating film, it is also preferable because the oxide of B formed by surface oxidation during cutting particularly densifies the oxide of Al. Furthermore, since the oxide of B has a low melting point as in the case of the oxide of V, it acts as a lubricant during cutting and exhibits the effect of suppressing adhesion of the work material. If the coating film contains Si or B atoms in an atomic percent of 10% or more, it is not preferable because an alloy target is easily cracked during firing when it is produced by hot isostatic pressing. More preferably, the coating film contains Si atoms or B atoms in the range of 3% to 6% in atomic percent.

  In the coated cutting tool of the present invention, the internal compressive stress or hardness in the coating film changes continuously or stepwise in the film thickness direction in the coating film. In particular, the wear resistance is improved when the internal compressive stress or hardness in the coating film changes continuously or stepwise from the surface of the substrate to the surface of the coating film, and becomes maximum on the surface of the coating film. To do. However, as in the conventional method, when a high hardness film is simply coated from the substrate surface with internal compression stress or hardness over its thickness direction, the coating film is affected by the internal compression stress at the sharp blade edge. Will peel off, which is insufficient as a wear-resistant coating film.

  Further, in the present invention, the internal compressive stress or hardness in the coating film changes continuously or stepwise in the coating film thickness direction from the substrate surface to the coating film surface, and is maximum on the substrate surface side. It can also coat | cover. In this case, although the hardness on the surface of the coating film is lower than the hardness on the substrate side of the coating film, on the contrary, the toughness of the coating film is improved. It is preferable because film peeling or chipping of the blade edge that occurs when an impact is applied can be suppressed.

  In the present invention, continuously changing means that the position in the film thickness can be represented by a linear regression curve in the relationship of the graph with the horizontal axis representing the hardness and the vertical axis representing the hardness. In the relationship of the graph with the horizontal axis representing hardness and the vertical axis representing hardness, it means having a step function relationship. Specifically, it demonstrates using FIGS. 1 to 4 show how to change the internal compressive stress and hardness in the coating film, where the vertical axis represents hardness or internal compressive stress, and the horizontal axis represents the substrate surface side at the position in the thickness direction in the film thickness. FIG. 1 shows a case where the internal compressive stress and hardness continuously increase, FIG. 2 shows a case where the internal compressive stress and hardness increase stepwise, FIG. 3 shows a case where the internal compressive stress and hardness continuously decrease, and FIG. 4 shows a case where the internal compressive stress and hardness decrease stepwise. 1-4, (A) shows the relationship between the hardness and the position in the film thickness, and (B) shows the relationship between the internal stress and the position in the film thickness.

  As can be seen from FIGS. 1 to 4, the continuous increase or decrease is the case of FIG. 1 or FIG. 3, and the stepwise increase or decrease is the case of FIG. 2 or FIG. 4.

  In the present invention, the internal compressive stress is preferably changed continuously or stepwise in the film thickness direction of the coating film in the range of −8 GPa to 0 GPa. If it is less than −8 Gpa, the film peels off at the edge of a particularly sharp cutting tool, which is not preferable. On the other hand, if it exceeds 0 Gpa, the stress of the film becomes tensile, and the film cracks and the crack progresses to the base material at the time of cutting, so that the deficiency is impaired. This internal compressive stress can be measured by a method using X-rays (a constant penetration depth method). In addition, the method of changing continuously or stepwise in the said range is as above-mentioned, and 2 types of increase or fall are mentioned in a film thickness direction.

  Moreover, in this invention, it is preferable to change the hardness of the thickness direction of the coating film by a nano indenter in the range of 18 GPa or more and 55 Gpa or less. If it is less than 18 Gpa, there is a problem in abrasion resistance, and if it exceeds 55 Gpa, the film peels off at the edge of a particularly sharp cutting tool, which is not preferable. In addition, the method of changing continuously or stepwise in the said range is as above-mentioned, and 2 types of increase or fall are mentioned in a film thickness direction. Here, the measurement of change in hardness can be obtained by measuring the hardness using a nanoindenter while changing the measurement weight (changing the maximum indentation depth). The nanoindentation method is a kind of hardness test as described in detail in the literature “Tribologist, Vol. 47, No. 3, (2002) p177-183”. The method for obtaining the hardness from the indented shape after indentation such as hardness measurement is different, and is a method for obtaining the hardness and Young's modulus from the relationship between the load and the depth when the indenter is indented.

  In the coated cutting tool of the present invention, the thickness of the coating film is preferably in the range of 0.5 to 15.0 μm. If the thickness is less than 0.5 μm, improvement in wear resistance is not observed. Conversely, if the thickness exceeds 15.0 μm, the internal compressive stress accumulated in the surface coating film increases and the adhesion strength with the base material decreases. It is not preferable. More preferably, it exists in the range of 2-6 micrometers. The thickness of such a coating film can be measured by cutting a coated cutting tool and observing the cross section using an SEM.

  In the coated cutting tool of the present invention, an intermediate layer may be further formed between the base material and the coating film. As the intermediate layer, Ti, Cr or Ti nitride, TiAl nitride, Cr nitride, or the like can be used. The intermediate layer using such a material has good adhesion to both the substrate surface and the coating film, and can further improve the adhesion between the substrate and the coating film. Therefore, the cutting tool life can be further improved without the coating film being peeled off from the substrate. In the present invention, when an intermediate layer is included, the thickness of the intermediate layer is preferably in the range of 0.005 to 5.0 μm. When the thickness is less than 0.005 μm, the adhesion strength is not improved. Conversely, when the thickness exceeds 5.0 μm, the adhesion strength is not further improved. More preferably, it is 0.005-0.5 micrometer.

  In the present invention, as the substrate, those that have been widely used in the art can be used as appropriate, and are not particularly limited, but because of the high hardness compared to the work material, WC-based cemented carbide, cermet, high-speed steel, ceramics (silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, etc.), cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body, aluminum oxide And a base material made of titanium carbide. Among them, it is particularly preferable to use a WC-based cemented carbide, cermet, or cubic boron nitride sintered body as a base material.

  The coated cutting tool of the present invention can be applied to various conventionally known cutting tools used for cutting. In particular, the coated cutting tool of the present invention is preferably a drill, an end mill, a milling and turning cutting edge replaceable tip, a metal saw, a gear cutting tool, a reamer, or a tap.

  In order to coat the surface of the substrate with the coating film of the present invention, it is indispensable to be produced by a film forming process capable of forming a compound having high crystallinity. Therefore, the present inventors have found that it is preferable to use a physical vapor deposition method among various film forming methods. Examples of the physical vapor deposition method include a sputtering method and an ion plating method. When manufacturing the coated cutting tool of the present invention, the arc type ion plating method is used when the ion plating method is employed. Is preferable for reasons of high adhesion and high-speed film formation (productivity).

  In particular, cathode arc ion plating with a high ion ratio of the raw material element is most suitable. When this cathode arc ion plating is used, it is possible to perform metal ion bombardment treatment on the surface of the base material before forming the surface coating, which is preferable from the viewpoint of adhesion because the adhesion of the coating is greatly improved. Is a process. When manufacturing a coated cutting tool by the cathode arc ion plating method, the coating film can be formed under the following conditions.

  In addition, the sputtering method may be used from the viewpoint of the smoothness of the coating, and when the sputtering method is employed, the magnetron sputtering method (balanced and unbalanced magnetron sputtering method) is used for high-speed film formation (production Is preferable for the reason. More preferably, an unbalanced magnetron sputtering method with a high ionization rate is preferable.

    Next, how the wear resistance of the coated cutting tool is improved will be specifically described with reference to examples. The composition in the examples was confirmed by XPS (PHI Quantera SXM (product name), manufactured by ULVAC-PHI), the crystal structure and internal compressive stress were confirmed by X-ray, and the hardness was confirmed by nanoindenter (Nano Indenter XP, manufactured by MTS). . The peritoneum can also be formed by a balanced or unbalanced sputtering method other than the cathode arc ion plating method described below.

(Examples 1-13, Comparative Examples 1-3)
(1) Preparation of sample i) Preparation of coated cutting tool of Examples 1 to 13 An ISO P30 cemented carbide having a shape of SPGN120308 was prepared as a base material. First, the inside of the chamber is depressurized by a vacuum pump, and the substrate is heated to a temperature of 650 ° C. by a heater installed in the apparatus, and evacuation is performed until the pressure in the chamber reaches 1.0 × 10 ⁻⁴ Pa. It was. Next, argon gas was introduced to maintain the pressure in the chamber at 3.0 Pa, the substrate bias power supply voltage was gradually increased to −1000 V, and the surface of the substrate was cleaned for 15 minutes. Thereafter, argon gas was exhausted.

  Next, an alloy target that is a metal evaporation source of the coating film component, and a gas from which nitrogen, methane, oxygen, and carbon monoxide as components corresponding to the coating film in Examples 1 to 13 are obtained as a reaction gas While the substrate was introduced, a substrate temperature of 650 ° C., a reaction gas pressure of 2.0 Pa, an arc current of 120 A was supplied to the cathode electrode, and metal ions were generated from the arc evaporation source. A film was formed. At this time, for example, as a method of applying the voltage of the substrate bias power source, when the voltage is changed from 10 V to continuous 200 V while applying the voltage for 60 minutes, the internal compressive stress or hardness continuously increases in the film as shown in FIG. A film having the maximum thickness at the outermost surface of the film can be obtained. Moreover, what is necessary is just to reverse the way of said voltage application in order to obtain a film like FIG. Also, as shown in FIG. 2 and FIG. 4, in order to change the internal compressive stress or hardness stepwise, the substrate bias voltage is stepped with respect to time, for example, 10V⇔40V⇔60V⇔120V⇔200V (five steps). Just raise it. Other control methods are fixed this time, but the internal compressive stress and hardness can be controlled even if the film forming pressure or film forming temperature is changed.

  In addition, for comparison with the products of the present invention, as Comparative Examples 1 to 3, films were prepared with the substrate bias fixed during film formation.

(2) Coated cutting tool life evaluation About each of the coated cutting tool of Examples 1-13 which are the samples manufactured at the above-mentioned process, and the conventional product of Comparative Examples 1-3, the dry continuous cutting test by the conditions of Table 2 and An intermittent cutting test was performed, and the flank wear width of the cutting edge was measured. The life evaluation results are shown in Table 1 for Examples 1 to 13 and Table 2 for Comparative Examples 1 to 3.

  As apparent from Table 1, it was confirmed that the cutting tool life was greatly improved in the present invention. In addition, the coated cutting tools of Examples 5 to 7 whose internal compressive stress or hardness was reduced on the surface showed good results in intermittent cutting, and an effect on the impact resistance was seen.

(Examples 14-16, Comparative Examples 4-6)
Except that JISK10 cemented carbide was used as the base material, each of the drills having an outer diameter of 8 mm was coated by the same method as in Examples 1 to 13, and Examples 1, 7 and 8 and Comparative Examples 1 to 3 were applied. Samples coated with the same coating as the coating film of the described coated cutting tool were obtained and used as the coated cutting tools of Examples 14 to 16 and Comparative Examples 4 to 6, respectively. Next, using these coated cutting tools, the drilling of SCM440 (HRC30) was actually performed to evaluate the life. Cutting conditions were a cutting speed of 90 m / min, a feed amount of 0.2 mm / rev, no cutting fluid (using air blow), and a blind hole with a depth of 24 mm. Note that the life was determined when the dimensional accuracy of the workpiece was outside the specified range. The life evaluation results are shown in Table 3.

  As a result, it was confirmed that the life of the drill of the present invention was greatly improved.

(Examples 17-19 and Comparative Examples 7-9)
Coating was performed in exactly the same manner as in Example 1 except that a 6-flute end mill (JIS K10 cemented carbide) having an outer diameter of 8 mm was used as the substrate. The coating films used were the coating films of Examples 1, 7, and 8 and Comparative Examples 1, 2, and 3, and the coated cutting tools of Examples 17-19 and Comparative Examples 7-9 were used, respectively. Next, using these coated cutting tools, end mill side milling of SKD11 (HRC60) was actually performed to evaluate the life. Cutting conditions were a cutting speed of 200 m / min, a feed of 0.03 mm / blade, a cutting amount Ad = 12 mm, Rd = 0.2 mm, and side cutting was performed without using a cutting fluid (using air blow). Note that the life was determined when the dimensional accuracy of the workpiece was outside the specified range. The life evaluation results are shown in Table 4.

  As a result, it was confirmed that the life of the end mill of the present invention was greatly improved.

(Examples 20-22 and Comparative Examples 10-12)
First, using a cemented carbide pot and balls, a binder powder composed of 40% TiN and 10% Al by mass and a cBN powder of 50% average particle size of 2.5 μm are mixed together to form a cemented carbide container. And sintered at a pressure of 5 Gpa and a temperature of 1400 ° C. for 60 minutes. This cBN sintered body was processed to obtain a cutting tip having a shape of ISO standard SNGA120408.

  The chips were coated with the coating films of Examples 1, 7, and 8 and Comparative Examples 1, 2, and 3 in the same manner as in Example 1, and coatings of Examples 20-22 and Comparative Examples 10-12, respectively. A cutting tool was obtained. Using this coated cutting tool, outer peripheral cutting of SUJ2 round bar (HRC62), which is a kind of hardened steel, was performed. Cutting was performed under the conditions of a cutting speed of 120 m / min, a cutting depth of 0.2 mm, a feed of 0.1 mm / rev, and a dry method for 40 minutes, and the flank wear amount was examined. The results are shown in Table 5, and it was confirmed that the lifetimes of the cutting tips of Examples 20 to 22 were greatly improved.

(Example 23 and Comparative Examples 13 and 14)
A coated cutting tool was produced by the same procedure as in Example 1 except that the grade was a JIS standard S20 cemented carbide and the chip shape was JIS standard CNMG120408 as a base material. In addition, what used the thing of Example 9 as a coating film was made into Example 23, and what used the coating film of the comparative examples 1 and 2 was set as the cutting coating tool of the comparative examples 13 and 14, respectively. These cutting-coated tools were actually subjected to a wet (water-soluble emulsion) continuous turning test under the following conditions, and the time when the flank wear width of the cutting edge exceeded 0.2 mm was measured. Cutting conditions were a work material and a Ti alloy Ti-6Al-4V (HB = 310), a cutting speed of 80 m / min, a feed amount of 0.2 mm / rev, and a cutting depth of 1 mm. As a result, the coated cutting tool of Example 23 was capable of cutting for 30 minutes, while the cutting tool of Comparative Example 13 was chipped in 1 minute and the tool of Comparative Example 14 was chipped in 2 minutes. Interrupted. From this, it was confirmed that the life of the cutting tip of the present invention has been greatly improved. This is presumably because the conventional product contains Ti in the film, but the product of the present invention does not contain Ti at all, so that the adhesion resistance of the film can be improved.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The coated cutting tool of the present invention can be used for cutting of drills, end mills, milling and turning cutting tips, metal saws, gear cutting tools, reamers, taps, and the like.

It is a figure showing using a graph with respect to the position in a coating film about the case where the internal stress or hardness in a coating film in the coated cutting tool of this invention increases continuously. It is a figure showing using a graph with respect to the position in a coating film about the case where the internal stress or hardness in a coating film in the coated cutting tool of this invention increases in steps. It is a figure showing using a graph with respect to the position in a coating film about the case where the internal stress or hardness in a coating film in the coated cutting tool of this invention reduces continuously. It is a figure showing using a graph with respect to the position in a coating film about the case where the internal stress or hardness in a coating film in the coated cutting tool of this invention reduces in steps.

Claims (11)

In a coated cutting tool comprising a substrate and a coating film formed on the surface of the substrate, the coating film includes (Al _x-1 V _x ) nitride, carbonitride, nitride oxide, and A coated cutting tool characterized in that it is any of carbonitride oxides, wherein x is 0.24 or more and 0.45 or less.   The residual compressive stress or hardness of the coating film changes continuously or stepwise from the base material to the surface of the peritoneum. Coated cutting tool.   The internal compressive stress of the coating film increases continuously or stepwise from the base material to the surface of the coating film in the range of −8 GPa or more and 0 GPa or less, or the nanoindenter of the peritoneum 3. The coated cutting tool according to claim 1, wherein the hardness according to claim 1 increases continuously or stepwise from the base material to the surface of the coating film in a range of 18 GPa to 55 GPa.   The internal compressive stress of the coating film decreases continuously or stepwise from the substrate to the surface of the coating film in the range of −8 GPa to 0 GPa, or the nanoindenter of the coating film 3. The hardness according to claim 1, wherein the hardness decreases continuously or stepwise from the base material side to the surface side of the peritoneum in a range of 18 GPa to 55 GPa. Coated cutting tool described in 1.   The coated cutting tool according to any one of claims 1 to 4, wherein a thickness of the peritoneum is 0.5 µm or more and 15.0 µm or less.   Ti or Cr, Ti nitride, TiAl nitride, or Cr nitride having a thickness of 0.005 μm or more and 5.0 μm or less is used as an adhesion reinforcing layer between the base material and the coating film. The coated cutting tool according to claim 1, wherein the coated cutting tool is provided.   The coated cutting tool according to any one of claims 1 to 6, wherein the crystalline structure of the peritoneum is a cubic crystal.   The base material may be any of WC-based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, boron nitride sintered body, and a base material made of aluminum oxide and titanium carbide. The coated cutting tool according to any one of claims 1 to 7.   The coated cutting tool according to any one of claims 1 to 8, wherein the coated cutting tool is used as a drill, an end mill, a milling and turning cutting edge exchangeable tip, a metal saw, a cutting tool, a reamer, and a tap.   The coated cutting tool according to claim 1, wherein the coating film is coated by a physical vapor deposition method.   The coated cutting tool according to claim 1, wherein the coating film is coated by an arc ion plating method or a magnetron sputtering method.

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