JP2006181705A - Surface coated cutting tool and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface coated cutting tool, preventing a defect at the knife edge of a cutting tool and the oxidation of a base material, and having a coating layer exhibiting excellent cutting performance, and a manufacturing method thereof. <P>SOLUTION: This surface coated cutting tool includes a base material, and the coating film laminated on the surface of the base material, wherein the coating film is composed of an A layer, a B layer and a C layer, the A layer is made of a nitride of Ti<SB>a</SB>Si<SB>b</SB>(wherein 0<b<0.3, a+b=1) formed directly on the base material, the B layer is made of nitride, carbonitride, nitroxide or carbonitride of Al<SB>c</SB>Ti<SB>d</SB>M<SB>e</SB>(wherein 0.4<c<0.75, 0<e<0.3, c+d+e=1 )(M is one or more kinds of elements selected from a group of Si, Cr, V, Y, Zr, B, Zn, Mo and Mn), and the C layer is made of carbonitride of Ti<SB>f</SB>Si<SB>g</SB>(wherein 0<g<0.3, f+g=1) formed directly on the B layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cutting tool such as a drill, an end mill, a milling or turning cutting edge replaceable tip, a metal saw, a cutting tool, a reamer, or a tap, and in particular, a cutting in which a coating layer having wear resistance is formed on the surface thereof. The present invention relates to a tool and a manufacturing method thereof.

  Recent cutting tool trends include the need for dry machining without cutting fluids from the viewpoint of global environmental conservation, the diversification of work materials, and higher cutting speeds to further improve machining efficiency. For example, the tool edge temperature tends to become higher. As a result, the tool life is shortened, and the properties required for the tool material are becoming stricter.

  In particular, the required properties of the tool material include not only the stability of the coating film at high temperatures (oxidation resistance and adhesion of the coating film), but also the wear resistance related to the cutting tool life, ie the coating film Improvements in hardness at high temperatures and lubrication properties of coating films that replace lubricants are becoming increasingly important.

  Here, the structure of the cutting edge of a general cutting tool will be described. FIG. 1 shows a schematic cross-sectional view of a typical cutting edge of a cutting tool. In FIG. 1, a tool 1 includes a base material 2 and a coating layer 3 formed on the surface of the base material 2. The cutting edge is constituted by the rake face 4 of the tool and the flank face 5 of the tool. In many cases, the angle formed by the rake face 4 and the flank face 5 is an acute angle or a right angle. When the coating layer is formed on such a tool blade edge, the film thickness of the coating edge layer 8 becomes the largest compared to the rake face film thickness 6 and the flank face film thickness 7 as shown in the figure.

  Furthermore, the ideal wear progress at the tool edge will be described with reference to FIGS. The ideal wear as a tool is that the coating layer gradually wears away from the acute angle or right-angled portion indicated by the film thickness 8 as shown in FIG. 2 (a), and eventually the substrate as shown in FIG. 2 (b). After reaching the above, finally, as shown in FIG. 2C, the coating layer and the base material are both exposed and worn.

  However, as a result of detailed investigations of the tool wear part by the inventors, the wear at the tip of the cutting edge does not proceed as shown in FIG. 2 described above, and the edge of the cutting edge is already at line X as shown in FIG. It was found that the base material was lost due to the chipping shown, and the portion 10 of the base material was completely exposed and lost from its form. In addition, the base material 11 of the defective portion has already been oxidized, and no matter how good the oxidation resistance and wear resistance of the film, if the base material is exposed at the initial stage of cutting, the tool life is remarkably improved. It seems difficult.

  Therefore, in cutting tools under severe conditions such as high speed machining and dry machining, not only the oxidation resistance of the coating film is improved, but also the chipping or chipping of the cutting edge that occurs at the beginning of cutting, that is, the exposure of the substrate It is very important how to suppress this.

  On the other hand, in Non-Patent Document 1 below, the surface of a hard base material such as a cutting tool such as a WC-based cemented carbide, cermet, and high-speed steel, or a wear-resistant tool is used to improve wear resistance and surface protection function. In addition, it is disclosed that a single layer or a plurality of layers of TiAl nitride are formed as a hard coating layer.

  However, in recent high-speed machining and dry machining, the cutting edge temperature of the tool reaches 900 ° C. or higher, and therefore, a sufficient tool life cannot be obtained with the TiAlN coating.

  Further, Patent Document 1 and Patent Document 2 listed below describe nitrides, carbonitrides, nitride oxides or carbonitride oxides containing Ti as a main component and containing Ti in an appropriate amount for improving heat resistance, and Ti and It is disclosed that a nitride, carbonitride, nitrided oxide, or carbonitride multilayer coating containing Al as a main component is applied to a cutting tool. The TiSi-based film has a dense oxidation protective film containing Si formed on the outermost surface, and has better heat resistance than the TiAl-based film.

  However, since the TiSi-based coating itself is highly brittle, there has been a problem that the entire coating is broken or peeled off by an impact during cutting. In the invention described in the patent document, in order to improve the adhesion between the base material and the film, a film mainly composed of TiN or TiAl is formed immediately above the base material. When the coating composed of TiN or TiAl as a main component is exposed on the surface, the progress of the oxidation is accelerated and the interior of the substrate is oxidized to reach the tool life, which is a problem.

Furthermore, in Patent Document 3 below, TiSi nitride is arranged directly on the base material, but under the film forming conditions disclosed in Reference Document 3, the compressive stress in the film is very high, and the pressure with the base material The problem is that the adhesion strength of the coating due to the difference is extremely lowered.
Japanese Patent No. 3347687 Japanese Patent No. 3248897 Japanese Patent No. 3480086 Kobe Steel Engineering Reports Vo. 41 no. 3 (1991) page 10

  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 TiSi-based film having a higher adhesion directly on the base material and to form a laminate of the film with a specific structure. To provide a lubricating function to the coating film, thereby reducing the temperature of the tool edge during high-speed and dry machining, and at the same time, achieving a longer service life and its manufacture It is to provide a method.

According to one aspect of the present invention, there is provided a surface-coated cutting tool comprising a base material and a coating film laminated on the surface of the base material, wherein the coating film is formed directly on the base material. _Ti a Si _b (However, 0 <b <0.3, a + b = 1) that the a layer made of a nitride of the _Al c is formed on the a layer directly _Ti d _{M e} (where 0.4 < c <0.75, 0 <e <0.3, c + d + e = 1) (wherein M is one or more elements selected from the group consisting of Si, Cr, V, Y, Zr, B, Zn, Mo and Mn) ) Nitrides, carbonitrides, nitride oxides or carbonitrides, and Ti _f Si _g (where 0 <g <0.3, f + g = 1) formed immediately above the B layer. A surface-coated cutting tool characterized by comprising a carbon layer made of carbonitride is provided.

  Preferably, the coating layer has a total film thickness in the range of 0.5 μm to 10 μm.

  Preferably, the coating layer has a thickness of the A layer in the range of 0.05 μm to 1.0 μm.

  Preferably, in the coating layer, the thicknesses of the B layer and the C layer are each independently in the range of 0.05 μm or more and 6 μm or less.

  Preferably, the base material is selected from the group consisting of WC-based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body, aluminum oxide and titanium carbide. A base material using one or more selected materials.

According to another aspect of the present invention, there is provided a method for manufacturing a surface-coated cutting tool comprising a base material and a coating film formed on the surface of the base material, wherein Ti _a Si is formed directly on the base material. _b (where 0 <b <0.3, a + b = 1) a step of forming an A layer made of nitride, and Al _c Ti _{d Me} (where 0.4 <c <0 .75, 0 <e <0.3, c + d + e = 1) (wherein M is one or more elements selected from the group consisting of Si, Cr, V, Y, Zr, B, Zn, Mo and Mn) Forming a B layer made of a material, carbonitride, nitride oxide or carbonitride, and carbonitriding of Ti _f Si _g (where 0 <g <0.3, f + g = 1) immediately above the B layer A method for producing a surface-coated cutting tool is provided, which includes a step of forming a C layer made of an object.

  Preferably, the step of laminating and forming the A layer is performed using a physical vapor deposition method, in which the bias power source is in the range of 0 to 30 V and the pressure of the nitrogen gas is in the range of 3 to 6 Pa. The substrate temperature is set to 450 ° C. or higher.

  Preferably, the step of forming the C layer uses a physical vapor deposition method, and the bias voltage is set to 200 V or higher.

  According to the surface-coated cutting tool of the present invention, it is possible to improve wear resistance, oxidation resistance, and heat resistance by imparting a specific structure to the coating film, thereby improving the life of the cutting tool. Can do.

The present invention will be described with reference to FIG. As shown in FIG. 4, the surface-coated cutting tool 1 of the present invention includes a base material 2 and a coating film that is laminated on the surface of the base material. The coating film is formed on the A layer 12 made of nitride of Ti _a Si _b (where 0 <b <0.3, a + b = 1) formed directly on the substrate, and on the A layer 12. al _c Ti _d M _e (however, 0.4 <c <0.75,0 <e <0.3, c + d + e = 1) (M is Si, Cr, V, Y, Zr, B, Zn, Mo and B layer made of nitride, carbonitride, nitride oxide or carbonitride of one or more elements selected from the group consisting of Mn, and Ti _f Si _g (provided that 0) <G <0.3, f + g = 1).

As described above, the surface-coated cutting tool 1 of the present invention provides adhesion between the base material 2 and the A layer 12 made of nitride of Ti _a Si _b (where 0 <b <0.3, a + b = 1). than conventionally is strengthened further, just above the a _layer, Al c _Ti d _{M e} (however, 0.4 <c <0.75,0 <e <0.3, c + d + e = 1) (M is Si, Forming a B layer made of nitride, carbonitride, nitride oxide or carbonitride of one or more elements selected from the group consisting of Cr, V, Y, Zr, B, Zn, Mo and Mn, By forming a C layer which is a carbonitride of Ti _f Si _g (where 0 <g <0.3, f + g = 1) just above the B layer, the coating film as a whole has excellent wear resistance and acid resistance. And heat resistance can be achieved, and therefore the life as a cutting tool can be improved.

(Coating layer)
In the surface-coated cutting tool of the present invention, an A layer made of a nitride of Ti _a Si _b (where 0 <b <0.3, a + b = 1) is formed directly on the base material in the coating layer. The A layer is excellent in oxidation resistance, and can protect the base material from oxidation even if the wear of the coating film proceeds.

  In the present invention, the A layer is characterized in that the adhesion to the substrate is greatly improved as compared with a conventional film having the same composition. That is, conventionally, the film is generally formed by a physical vapor deposition method such as an arc ion plating method, but TiSiN has a high compressive residual stress and is easily peeled off due to a large stress difference from the substrate.

  In the physical vapor deposition method, the inventors set the bias voltage applied to the substrate within a range of 0 to 30 V, the nitrogen gas pressure within a range of 3 to 6 Pa, and the substrate temperature of 450. It has been found that by setting the temperature to not less than ° C., the stress of TiSiN is reduced, and thus the adhesion to the substrate is greatly improved.

  The above condition is a value that is difficult to conceive conventionally in the field, that is, in the present invention, the above condition has a very low bias voltage, a very high nitrogen gas pressure, and a substrate temperature as compared with the conventional condition. It is set relatively high.

  That is, in the conventional technical common sense, if the bias voltage is set low as defined in the present invention during film formation, the compressive stress in the coating film is too low, and the strength of the coating film may be extremely reduced. If the nitrogen gas pressure is increased, the exhaust capacity of the vacuum pump may be insufficient and the furnace pressure may become unstable.If the substrate temperature is increased, the compressive stress in the coating film is released, There was a possibility that the film strength would decrease. In this respect, it can be said that the setting of such conditions in the present invention is far from the range of technical design items that can be easily assumed by those skilled in the art.

  More preferably, the bias voltage applied to the substrate is in the range of 15 to 25 V, the pressure of the nitrogen gas is in the range of 4 to 5 Pa, and the substrate temperature is 500 ° C. or higher.

In the present invention, the A layer has a nitride composition of Ti _a Si _b (where 0 <b <0.3, a + b = 1). By setting the composition of TiSi in the A layer, an excellent effect of high hardness and high heat resistance can be obtained. Moreover, it can be set as the film | membrane excellent in adhesiveness with a base material by making this into nitride.

In the present invention, in the composition of the layer A: Ti _a Si _b (where 0 <b <0.3, a + b = 1), 0 <b <0.3. When Si is 30 atomic% or more, that is, when b exceeds 0.3, the toughness of the A layer is lowered, which is not preferable. More preferably, 10 <b <25. Here, a and b indicate the composition ratio of atoms of Ti and Si.

  In the present invention, the thickness of the A layer is preferably 0.05 μm or more and 1.0 μm or less. When the thickness is less than 0.05 μm, the effect of heat resistance is reduced, and when it exceeds 1.0 μm, the coating itself has high brittleness and may be broken by an impact during cutting. More preferably, it is 0.1 μm or more and 0.3 μm or less.

  In the present invention, a B layer is formed immediately above the A layer. The B layer will be described below.

In the present invention, B _layer, Al c _Ti d _{M e} (however, 0.4 <c <0.75,0 <e <0.3, c + d + e = 1) (M is Si, Cr, V, Y, 1 type or more of elements selected from the group consisting of Zr, B, Zn, Mo and Mn) nitride, carbonitride, nitride oxide or carbonitride. By having the composition of AlTi, it is possible to achieve a good balance between wear resistance and toughness. Further, the B layer further includes one or more elements selected from the group consisting of Si, Cr, V, Y, Zr, B, Zn, Mo and Mn as the metal element M, thereby further improving the hardness. To do.

  M in the B layer in the present invention can use Si, Cr, V, Y, Zr, B, Zn, Mo, and Mn elements. These elements are used in AlTi nitride and carbonitride. Since it has a common feature of acting as a solid solution element and distorting the crystal, the effect of improving the hardness can be exhibited by using any element. In particular, Si or Cr is a preferable element from the viewpoint of improving heat resistance.

In B layer in the present _invention, Al c _Ti d _{M e} has a 0.4 <c <0.75,0 <e < 0.3, the composition ratio of c + d + e = 1. If the Al content is 40 atomic% or less, the heat resistance may be reduced, and if it exceeds 75 atomic%, that is, if c exceeds 0.75, the strength of the coating film may be reduced. More preferably, 45 <c <65. Here, c, d, and e indicate the composition ratio of the atoms.

  Further, in the B layer in the present invention, the M defined above is not preferable if the composition ratio exceeds 30 atomic% because the toughness of the B layer is lowered. More preferably, 3 <e <10.

  Moreover, it is preferable that the film thickness of the said B layer exists in the range of 0.05 micrometer-6 micrometers. If it is less than 0.05 μm, it is difficult to form a stable film such as switching the gas type at the time of film formation and controlling the bias voltage. Therefore, if it exceeds 6 μm, it is difficult to form a film. Due to the compressive stress, the coating itself is more susceptible to self-destruction and the strength is not preferred. More preferably, it exists in the range of 2 micrometers-4 micrometers.

Next, the C layer formed immediately above the B layer will be described. The C layer in the present invention is a carbonitride of Ti _f Si _g (where 0 <g <0.3, f + g = 1). The C layer having such a composition exhibits excellent heat resistance and lubricity due to the composition of TiSi, and by using carbonitride, it has a structure in which carbon is dispersed in the coating. Compared with the above, the friction coefficient is low, and the lubricity can be further improved.

  In the C layer in the present invention, if Si is 30 atomic% or more, the strength of the coating film may be lowered, which is a problem. More preferably, 10 <g <25.

  The C layer in the present invention can be formed by a physical vapor deposition method, specifically, an arc ion plating method. Conventionally, since the bias power source is about 30 to 100 V, methane, which is a reactive gas, is used. And acetylene gas was not sufficiently decomposed, and a dense TiSi carbonitride was not obtained. Such a film has a structure in which carbon is partially deposited, resulting in a decrease in heat resistance and strength.

  In the present invention, by setting the bias voltage to a very high value of 200 V or more as a film formation condition for the C layer, both heat resistance and lubricity are excellent and dense TiSi is used. It became possible to form a carbonitride film. It can be said that setting such a high bias voltage is extremely epoch-making in view of conventional technical common knowledge that when the bias voltage is increased, there is a possibility that the film forming speed may be significantly reduced.

  As described above, by imparting excellent lubricity and heat resistance to the C layer according to the present invention, the cutting edge temperature of the tool can be lowered, and oxidation of the entire coating film can be prevented. Thus, the work material is prevented from welding to the cutting edge, and the roughness of the processed surface is improved.

  Moreover, it is preferable that the film thickness of the said C layer exists in the range of 0.05 micrometer-6 micrometers. If it is less than 0.05 μm, it is difficult to form a stable film such as switching the gas type at the time of film formation and controlling the bias voltage. Therefore, if it exceeds 6 μm, it is difficult to form a film. The film itself is easily self-destructed by the compressive stress and the strength is lowered, which is not preferable. More preferably, it exists in the range of 1.0 micrometer-3.0 micrometers.

  In the present invention, by laminating the A layer, the B layer, and the C layer in this order on the substrate as described above, the performance of the tool can be improved in high-speed machining and dry machining. Specifically, in the case of a single layer structure such as only the A layer, only the B layer, or only the C layer, the entire coating film may be broken or peeled off by an impact generated during cutting. Although there is a problem that the tool life is reduced, as described above, by using the three-layer structure of A, B, and C, the coating film is destroyed by the impact during cutting, and each layer, that is, B Since it is suppressed between the layer and the C layer or between the A layer and the B layer, there is an advantage that the destruction unit of the coating film is reduced. In addition, due to the difference in lattice constant between the B layer and the C layer, each crystal is distorted and the hardness can be increased.

  In the present invention, the total thickness of the coating film is preferably in the range of 0.5 μm or more and 10 μm or less. If it is less than 0.5 μm, the wear resistance may be reduced, and if it exceeds 10 μm, the toughness of the coating film may be reduced. More preferably, it is 2.5 μm or more and 6.0 μm or less.

  In the present invention, as a method for measuring the thickness of each layer and the thickness of the entire coating layer described above, the tool can be cut and its cross section can be observed using an SEM (scanning electron microscope).

  In the present invention, the uppermost layer of the coating layer is a C layer. Since the C layer exhibits a purple color, the design property as a tool can be improved and is commercially useful.

  In the present invention, in order to coat the coating film on the surface of the base material, it is indispensable to be produced by a film forming process capable of forming a compound having high crystallinity. Therefore, as a result of examining various film forming methods, it is preferable to use a physical vapor deposition method. The physical vapor deposition method includes balanced and unbalanced magnetron sputtering methods, ion plating methods, and the like. Cathode arc ion plating with a high ion ratio of the raw material elements is particularly suitable. When this cathode arc ion plating is used, since the metal ion bombardment treatment can be performed on the surface of the base material before the coating layer is formed, the adhesion between the base material and the coating layer is remarkably improved. This is a preferable process from the viewpoint of adhesion.

(Base material)
The base material in the present invention is a group consisting of WC-based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body, aluminum oxide and titanium carbide. A base material using one or more selected materials.

  In particular, the coated coated cutting tool is preferably a drill, an end mill, a milling or turning cutting edge replaceable tip, a metal saw, a gear cutting tool, a reamer, or a tap.

  This embodiment will explain the surface-coated cutting tool of the present invention in more detail, and further specifically explain how the characteristics such as wear resistance of the tool are improved. In the examples, the composition in the coating film was measured using XPS (X-ray photoelectron spectroscopy analyzer), and the hardness of the coating film was confirmed by a nanoindenter (Nano Indenter XP manufactured by MTS). Moreover, the film thickness in a coating film was measured using SEM as above-mentioned.

  In this embodiment, the coating film of the tool is formed by using the cathode arc ion plating method. However, other than this, for example, the film can also be formed by the balanced or unbalanced sputtering method. Is possible.

<Production of surface-coated cutting tool>
(1) Cleaning of base material As a base material, a cemented carbide end mill (φ10, 6 blades) with a grade of JIS standard K10, a cemented carbide drill (φ8) with a grade of JIS standard K30, and a grade of JIS standard P30. A cemented carbide milling throw-away tip (shape: SDKN42) was prepared and mounted on a cathode arc ion plating apparatus as shown in FIG.

  In the apparatus of FIGS. 5 and 6, a rotary type for installing arc type evaporation sources 106, 107, 111 for the A layer, the B layer and the C layer constituting the coating film, and the base material in the chamber 101. A substrate holder 104 is attached. Arc power sources 108 and 109 are attached to the arc evaporation sources 106, 107, and 111, respectively. A bias power source 110 is attached to the substrate holder 104. Further, the chamber 101 is provided with a port through which the reaction gas 105 is introduced, and has a structure in which gas can be sucked from the port 103 for adjusting the pressure in the chamber 101 by a vacuum pump.

In the apparatus of FIG. 5, first, the inside of the chamber 101 is depressurized by a vacuum pump, and the temperature is heated to 500 ° C. by a heater installed in the apparatus while rotating the substrate, so that the pressure in the chamber is 1.0 × Vacuuming was performed until 10 ⁻⁴ Pa was reached. Next, argon gas was introduced to maintain the pressure in the chamber 101 at 3.0 Pa, and while gradually increasing the voltage of the substrate bias power supply 110, the substrate surface was cleaned for 15 minutes. Thereafter, argon gas was exhausted.

(2) Formation of coating film Next, Ti _a Si _b , Al _c Ti _{d Me} (where M is Si, Cr, V, Y, Zr, B, Zn, Mo and one or more elements selected from the group consisting of Mn) and _Ti f Si _g was placed in one of 106,107,111. In addition, the said M used what was selected from the above suitably according to the target composition. In addition, a, b, c, d, e, f, and g indicating the atomic composition ratio are shown in the table, respectively.

  While the substrate 102 is rotated at the center, while introducing nitrogen gas as a reaction gas, the substrate temperature is maintained at 500 ° C., the reaction gas pressure is 5 Pa, and the substrate bias voltage is maintained at −20 V. Metal ions were generated from the target to form the A layer.

Next, after the A layer was formed, a B layer was formed. In order to laminate the B layer directly on the A layer, N ₂ gas was introduced so that the pressure in the chamber was 2.6 Pa, and the substrate temperature was set to 500 ° C. and the base material bias voltage was set to −70V. Then, the AlTiM target was ionized by arc discharge and reacted with N ₂ gas to laminate (AlTiM) N.

Next, in order to laminate the C layer immediately above the B layer, N ₂ gas and CH ₄ gas are introduced so that the pressure in the chamber becomes 2.6 Pa, the substrate temperature is 500 ° C., and the base material bias voltage is −200 V. It was. The TiSi target was ionized by arc discharge and reacted with N ₂ gas and CH ₄ gas to form a TiSiCN film.

  Thus, the A layer, the B layer, and the C layer were laminated. Note that the film thickness of each of the A, B, and C layers can be controlled by controlling the film formation time.

  Table 1 shows the coating film according to the present invention formed as described above, and Table 2 shows the conventional cutting tool.

  Each of the surface-coated cutting tools shown in Table 1 and Table 2 below was evaluated by performing the following tests.

<End mill cutting test>
In the end mill cutting test, a cemented carbide end mill with 6 blades and an outer diameter of 10 mm is used as a base material. 0.025 mm / tooth, cutting depth: Ad = 10 mm, Rd = 0.6 mm, air blow. The tool life was defined as the cutting distance when the wear width on the outer periphery of the cutting edge exceeded 0.1 mm. In this test, the longer the distance, the longer the life.

<Drill cutting test>
In the drill cutting test, a cemented carbide drill with an outer diameter of 8 mm is used as a base material, the work material is S50C, and a hole is drilled therein. Cutting speed: 70 m / min, feed rate: 0.25 mm / rev, hole Depth: The test was carried out under conditions of 30 mm through holes and no cutting oil. The tool life was defined as the number of holes processed when the wear width at the tip margin exceeded 0.2 mm. In this test, the longer the number of holes, the longer the tool life.

<Milling cutting test>
As the milling conditions, a P30-equivalent cemented carbide throw-away tip (shape: SDKN42) was used as a base material, and a direct 160 mm front milling was performed. The work material was SCM435, cutting speed: 250 mm / min, feed rate: 0.3 mm / tooth, cutting amount: 2 mm, and no cutting oil. The tool life was defined as the cutting distance when the wear width of the flank exceeded 0.2 mm. In the test, the longer the distance, the longer the tool life.

  From the results shown in Tables 1 and 2, the surface-coated cutting tool according to the present invention has a significantly improved tool life compared with conventional cutting tools, and has sufficient performance even under severe cutting conditions such as high-speed machining and dry machining. Can be demonstrated.

  Although the embodiments and examples of the present invention have been described as described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

  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.

It is a schematic diagram of the blade edge ridgeline part of the conventional cutting tool. It is a schematic diagram shown about the ideal progress of wear of a cutting tool. It is a schematic diagram which shows the example of the chipping which arises in the conventional cutting tool. It is a schematic diagram of the blade edge | tip part of the surface covering cutting tool of this invention. It is a schematic sectional drawing which shows the example of the apparatus used for the arc ion plating method. FIG. 6 is a schematic top view of the apparatus of FIG.

Explanation of symbols

  1 tool, 2 base material, 3 coating layer, 4 tool rake face, 5 tool rake face, 6 rake face film thickness, 7 flank face film thickness, 8 ridge line thickness, 10 base material exposed part, 11 Oxidized portion of substrate, 12 A layer, 13 B layer, 14 C layer, 101 chamber, 102 substrate, 103 ports, 104 rotating substrate holder, 105 reactive gas, 106, 107, 111 arc evaporation source, 108,109 Arc power supply, 110 Bias power supply.

Claims (8)

A surface-coated cutting tool comprising a base material and a coating film laminated on the surface of the base material,
The coating film includes an A layer made of a nitride of Ti _a Si _b (where 0 <b <0.3, a + b = 1) formed immediately above the base material, and an Al formed immediately above the A layer. _c Ti _d M _e (however, 0.4 <c <0.75,0 <e <0.3, c + d + e = 1) ( wherein M is Si, Cr, V, Y, Zr, B, Zn, Mo and B layer made of nitride, carbonitride, nitride oxide or carbonitride of one or more elements selected from the group consisting of Mn, and Ti _f Si _g (provided that 0) A surface-coated cutting tool comprising: a C layer made of carbonitride of <g <0.3, f + g = 1).   2. The surface-coated cutting tool according to claim 1, wherein the total thickness of the coating layer is in a range of 0.5 μm to 10 μm.   3. The surface-coated cutting tool according to claim 1, wherein the coating layer has a thickness of the A layer in a range of 0.05 μm to 1.0 μm.   The surface coating according to any one of claims 1 to 3, wherein in the coating layer, the thicknesses of the B layer and the C layer are each independently in the range of 0.05 µm to 6 µm. Cutting tools.   The substrate is selected from the group consisting of WC-based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body, aluminum oxide and titanium carbide. The surface-coated cutting tool according to claim 1, wherein the surface-coated cutting tool is a base material using one or more materials. A method for producing a surface-coated cutting tool comprising a base material and a coating film laminated on the surface of the base material,
Forming a layer A made of a nitride of Ti _a Si _b (where 0 <b <0.3, a + b = 1) directly on the substrate;
Directly the A _layer, Al c _Ti d _{M e} (however, 0.4 <c <0.75,0 <e <0.3, c + d + e = 1) ( wherein M is Si, Cr, V, Y, Zr , B, Zn, Mo, and one or more elements selected from the group consisting of Mn) forming a B layer made of nitride, carbonitride, nitride oxide or carbonitride;
Forming a C layer made of carbonitride of Ti _f Si _g (where 0 <g <0.3, f + g = 1) directly on the B layer;
A method for manufacturing a surface-coated cutting tool, comprising:   The step of laminating and forming the A layer is performed using a physical vapor deposition method, in which the bias power source is in the range of 0 to 30 V, the pressure of the nitrogen gas is in the range of 3 to 6 Pa, The method for manufacturing a surface-coated cutting tool according to claim 6, wherein the material temperature is set to 450 ° C. or higher.   The method for producing a surface-coated cutting tool according to claim 6 or 7, wherein the step of forming the C layer uses a physical vapor deposition method, and at that time, a bias voltage is set to 200 V or more.

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