JP2021126718A - Hard film cutting tool - Google Patents

Abstract

To provide a cutting tool exhibiting excellent cutting performance over a long-term use even when being used in high speed cutting of carbon steel, alloy steel, stainless steel, cast iron and the like.SOLUTION: A surface-coated cutting tool has a hard film layer 4 including a hard film 3 having average layer thickness of 0.5-10.0 μm (Me1-x-yAlxMy)Nz(0.35≤x≤0.80, 0.00≤y≤0.20, 0.20≤(1-x-y)≤0.65, and 0.90≤z≤1.10), on a surface of a tool substrate 1, in the expressions, Me is Ti or Cr; x, y and z are atomic ratios; M is an atom of groups 4 to 6 of the periodic table of IUPAC, and at least one of Y, Si, La and Ce. In an interface region 2 of a hard film layer 4 with an average thickness of 5-100 nm from the surface of the tool substrate 1 toward the tool surface, a content ratio of N to the total of Ti, Al, M and N on the surface side of the tool substrate 1 is 10-30 atom%, and increases from the surface of the tool substrate 1 toward the tool surface.SELECTED DRAWING: Figure 1

Description

The present invention relates to a surface-coated cutting tool (hereinafter, may be referred to as a coated tool).

In general, covering tools include inserts and covers that are detachably attached to the tip of a cutting tool for turning and planing of various types of steel (carbon steel, alloy steel) and cast iron. There are drills and miniature drills used for drilling and cutting of cutting materials, solid type end mills used for surface cutting, grooving, shoulder processing, etc. of the same work material, and inserts can be attached and detached freely. There are known insert-type end mills that can be attached and cut in the same way as solid-type end mills.

Conventionally, as a covering tool, for example, a covering tool in which a WC-based cemented carbide, a TiCN-based cermet, a cBN sintered body or the like is used as a tool base and a hard film layer is formed on the tool base has been known, and cutting performance has been obtained. Various proposals have been made for the purpose of improving.

For example, Patent Document 1 describes a hard film-coated tool in which a lower layer, an intermediate layer, and an upper layer are formed on a tool substrate.
(A) The lower layer is composed of at least one metal element selected from the group consisting of IV, V and VI elements, Al and Si, and at least one non-metal selected from the group consisting of N, C and B. Contains elements,
(B) the upper _{layer, (Al x Cr y) c} O d (x = 0.1~0.40, x + y = 1, c = 1.86~2.14, d = 2.79~3.21 ), The equivalent X-ray diffraction intensity ratio TC (110) is 1.3 or more, TC (110) is larger than TC (104), and TC (006) is 0. Consists of oxides
(C) The intermediate layer is composed of an oxynitride that requires Al and Cr as metal elements, and the oxygen concentration increases from the lower layer side to the upper layer side and the nitrogen concentration decreases from the lower layer side to the upper layer side. The average composition (Al _{s C t} ) _a (N _v O _w ) _b is s = 0.1-0.6, s + t = 1, v = 0.1-0.8, Satisfy v + w = 1, a = 0.35-0.6, a + b = 1.
A hard film coating tool characterized by this is described.

Further, in Patent Document 2, a total of two layers of TiAl nitride in the first layer and TiAl nitride in the second layer are formed on the surface of the tool substrate in order, and Ti: Al: N = α: β: γ. When
(1) The TiAl nitride in the first layer satisfies 0 <α / β ≦ 3, 0.2 ≦ (α + β) / γ ≦ 2.
(2) The TiAl nitride in the second layer satisfies 0 <α / β ≦ 3 and T = (α + β) / γ, T ₁ T _{2 continuously or intermittently from the base portion side to the surface portion side.} If T ₃ T ₄ ... T _n (n is arbitrary), it is a super-multilayer hard film satisfying _{2 ≧ T 1} ＞ T ₂ ＞ T ₃ ＞ T ₄ ＞ ・ ・ ・ ＞ T _{n ≧ 0.1.} ,
Cutting tools with a hard coating are described.

Further, Patent Document 3 describes that Al _a M _b (M is Ti, Ta, V, Cr, Zr, Nb, Mo, Hf, W, Fe, Co, Ni, Cu and Mn) on an wear-resistant base material. A reaction gas containing nitrogen, oxygen or carbon using an evaporation source material having a composition of at least one selected from the group consisting of 60 at% ≤ a ≤ 98.5 at%, 1.5 at% ≤ b ≤ 40 at%). An amorphous hard film having a high hardness in which the concentration of the reaction gas component in the amorphous film increases toward the film surface while controlling the supply amount of the reaction gas component so that the partial pressure changes continuously or stepwise. Is described, and it is shown that this hard film can be used as an electric / electronic material, a high-strength material, an abrasion-resistant material, a high-temperature resistant material, and the like.

In addition, Patent Document 4 has 2 coating layers on the substrate, and when the composition of the coating layer is MeNx, the inner coating layer has 0.5 <x <0.9, and the outer coating layer. Described a composite coated with an abrasion-resistant surface layer, wherein 0.9 <x ≦ 1.0, and the Me is a metal belonging to Groups III to IV of the periodic table. The body has been shown to be usable as a cutting tool.

Japanese Patent No. 5617933 Japanese Unexamined Patent Publication No. 10-237629 Japanese Unexamined Patent Publication No. 6-322517 Japanese Unexamined Patent Publication No. 59-159983

The coating tool having the hard coating layer (wear resistant layer) described in Patent Documents 1 to 4 has a hard coating layer at an early stage because the cutting edge becomes hot during high-speed cutting of carbon steel, alloy steel, stainless steel, cast iron and the like. As the composition of the steel changes, the hard film layer becomes brittle and reaches the end of its life in a short time, making it difficult to obtain satisfactory cutting performance. In this specification, high-speed cutting means 15% or more of the normal cutting speed for stainless steel, which generates a lot of heat during machining, and 30% or more of the conventional cutting speed for carbon steel, alloy steel, and cast iron. High-speed machining.

Therefore, the present invention exhibits excellent cutting performance over a long period of time because the hard film layer has excellent chipping resistance even when used for high-speed cutting of carbon steel, alloy steel, stainless steel, cast iron, etc. The purpose is to provide cutting tools.

The surface coating cutting tools according to the embodiment of the present invention are the following (1) and (2).
(1) The tool substrate and a hard film layer containing a composite nitride film having an average layer thickness of 0.5 to 10.0 μm are provided on the surface of the tool substrate.
It said composite nitride film is expressed by the _formula when expressed in _{(Ti 1-x-y Al} x M y) N z, 0.35 ≦ x ≦ 0.80,0.00 ≦ y ≦ 0.20,0 .20 ≦ (1-xy) ≦ 0.65, 0.90 ≦ z ≦ 1.10 (where x, y, z are atomic ratios, M is atoms of groups 4 to 6 of the periodic table of IUPAC, It has an average composition that satisfies at least one of Y, Si, La, and Ce), and has an average composition.
In the interface region of the hard coating layer having an average thickness in the range of 5 to 100 nm from the surface of the tool substrate to the tool surface, the content ratio of N to the total amount of Ti, Al, M and N is the above. The surface side of the tool substrate is 10 to 30 atomic%, and increases from the surface of the tool substrate toward the tool surface in the interface region.

(2) The tool substrate and a hard film layer containing at least a composite nitride film having an average layer thickness of 0.5 to 10.0 μm are provided on the surface of the tool substrate.
It said composite nitride film is expressed by the _formula when expressed in _{(Cr 1-x-y Al} x M y) N z, 0.35 ≦ x ≦ 0.80,0.00 ≦ y ≦ 0.20,0 .20 ≦ (1-xy) ≦ 0.65, 0.90 ≦ z ≦ 1.10 (where x, y, z are atomic ratios, M is atoms of groups 4 to 6 of the periodic table of IUPAC, It has an average composition that satisfies at least one of Y, Si, La, and Ce), and has an average composition.
In the interface region of the hard coating layer having an average thickness in the range of 5 to 100 nm from the surface of the tool substrate to the tool surface, the content ratio of N to the total amount of Cr, Al, M and N is the above. The surface side of the tool substrate is 10 to 30 atomic%, and increases from the surface of the tool substrate toward the tool surface in the interface region.

Surface-coated cutting tools that have a composite nitride film containing Al, Ti, and M in the hard film layer are suitable for high-speed cutting of alloy steel, cast iron, etc., and a composite nitride film containing Al, Cr, and M in the hard film layer. Even if the surface-coated cutting tool is used for high-speed cutting of carbon steel, stainless steel, etc., the hard film layer has excellent chipping resistance, so that it exhibits excellent cutting performance over a long period of use.

It is a schematic diagram of the vertical cross section of the hard film layer in the surface coating cutting tool of one Embodiment of this invention.

The present inventor has a composite nitride film containing Al, Ti and M, and a composite nitride film containing Al, Cr and M (where M is an atom of groups 4 to 6 of the periodic table of IUPAC, Y, Si). , La, and Ce, and the physical properties of the hard film layer having (TiAlM) N film and (CrAlM) N film, respectively) were studied diligently. As a result, the following findings were obtained.

(1) The hard film layer containing the (TiAlM) N film and the (CrAlM) N film having a small amount of N has excellent wear resistance even during high-speed cutting. The reason is presumed to be the high thermal stability of these films.
(2) When the N content (content ratio) is increased from the surface of the tool substrate toward the tool surface in the interface region between the tool substrate and the tool substrate (a predetermined range of the hard film layer near the surface of the tool substrate), cutting is performed. Performance is improved. The reason is that by increasing the N content ratio, decomposition of the hard film layer is less likely to occur, cracks generated near the interface can be suppressed, and the adhesion of the hard film layer is improved. I'm estimating.
Although Patent Documents 1 to 4 describe a film whose N content changes, none of them even suggests the findings of (1) and (2).

Hereinafter, the covering tool according to the embodiment of the present invention will be described in more detail. In the description of the scope of claims in this specification, when the numerical range is expressed using "A to B" (both A and B are numerical values), the range is the upper limit (B) and the lower limit (A). It includes numerical values. Moreover, the unit of the upper limit (B) and the lower limit (A) is the same. All numerical values allow measurement tolerances.

Hard film layer:
As shown in FIG. 1, the hard film layer 4 in the coating tool of the present embodiment is formed by forming a (TiAlM) N film or a (CrAlM) N film contained in the hard film 3 provided on the tool substrate 1. It has an interface region 2 in a predetermined range in the vicinity of the surface of the tool base 1.

The average thickness of the hard film layer is preferably 0.5 to 10.0 μm. The reason for this range is that if the average layer thickness is less than 0.5 μm, excellent wear resistance cannot be exhibited over a long period of use, while if the average layer thickness exceeds 10.0 μm, crystals will not be exhibited. This is because the grains tend to become coarse and the effect of improving the chipping resistance cannot be obtained.

(TiAlM) N film and (CrAlM) N film:
Contained in the hard coating layer in the coated tool of the present embodiment (TiAlM) N coating, the average composition, composition _formula: if expressed in _{(Ti 1-x-y Al} x M y) N z, also, the same (CrAlM) N coating, the average composition, composition _formula: when expressed in _{(Cr 1-x-y Al} x M y) N z, together, 0.35 ≦ x ≦ 0.80,0.00 ≦ y ≦ 0.20, 0.20 ≦ (1-xy) ≦ 0.65, 0.90 ≦ z ≦ 1.10 (where x, y, z are atomic ratios and M is the periodic table of IUPAC. It has an average composition that satisfies at least one of groups 4 to 6 atoms, Y, Si, La, and Ce).

The reason for determining the range of x, y, 1-xy, and z in this way is as follows.
If the value of x is less than 0.35, not only high hardness cannot be obtained, but also the crystal grains tend to be coarsened. On the other hand, if it exceeds 0.80, the crystal structure of some crystals is a NaCl-type face-centered cubic. The structure changes to a hexagonal structure, and the hardness decreases. A more preferable range is 0.45 ≦ x ≦ 0.70.

Further, when the average content ratio y of M added as needed exceeds 0.20, the toughness is lowered and chipping and chipping are likely to occur.
Further, when the value of (1-xy) is less than 0.20, the toughness is lowered due to the relative decrease in the Ti and Cr content ratios, and chipping and chipping are likely to occur, and 0.65 is set. If it exceeds, high hardness cannot be obtained.

In addition, by setting the value of z to 0.90 or more, the heat resistance is further improved and excellent wear resistance is exhibited. Further, when the value of z exceeds 1.10 and becomes large, the residual stress of the hard film layer becomes too large and the fracture resistance is lowered.

Regarding the average composition and average layer thickness of the (TiAlM) N film and the (CrAlM) N film, the scanning electron microscope (SEM), the transmission electron microscope (TEM), and the energy dispersive type It can be obtained by observing a cross section (longitudinal cross section perpendicular to the surface of the tool substrate) using X-ray spectroscopy (Energy Dispersive X-ray Spectroscope: EDS).

Interface area of hard film layer:
In the coated tool of the present embodiment, the combination of Ti, Al, M, and N in the interface region of the hard coating layer having an average thickness in the range (thickness) of 5 to 100 nm from the surface of the tool substrate to the tool surface. The content ratio of N with respect to the amount and the content ratio of N with respect to the total amount of Cr, Al, M, and N are both the tool from the surface side of the tool substrate (in the interface region, from the surface side of the tool substrate). Toward the surface side, the value of the film composition (Ti, Al, M, N) or (the point at which only atoms related to the film of (Cr, Al, M, N) began to be detected) was 10 to 30 respectively. In atomic%, the content ratio of N (the content ratio of N to the total amount of Ti, Al, M and N, and the content ratio of N to the total amount of Cr, Al, M and N) is the surface of the tool substrate. It is preferable that the amount increases from the surface toward the tool surface.

As a result, the (TiAlM) N film and the (CrAlM) N film are less likely to be decomposed in the interface region with the tool substrate where the composition change (decomposition) of the (TiAlM) N film and the (CrAlM) N film is likely to occur. It is considered that cracks generated in the vicinity of the interface region can be suppressed, and as a result, the adhesion between the tool substrate and the hard film layer is improved, and the cutting performance is improved. The average thickness of the interface region is more preferably in the range of 20-80 nm. The N content ratio in this interface region can be determined by TEM-EDS.

Tool base:
As the tool substrate, any substrate conventionally known as this type of tool substrate can be used as long as it does not hinder the achievement of the object of the present invention. For example, cemented carbide (WC-based cemented carbide, WC, as well as those containing Co and further added with carbonitrides such as Ti, Ta, Nb, etc.), cermet (TiC, TiN, TiCN, etc. as the main component), high-speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, etc.), cBN sintered body, or diamond sintered body It is preferable to have.

Production method:
The (TiAlM) N film and the (CrAlM) N film in the coating tool of the present embodiment can be produced by using an arc ion plating (AIP) device which is a kind of PVD. The interface region having an average thickness in the range of 5 to 100 nm from the surface of the tool substrate to the tool surface is formed by gradually increasing (for example, linearly increasing) the partial pressure of nitrogen gas, which is an atmospheric gas, from the start of film formation. can do.

Next, an example will be described. The present invention is not limited to the examples. An example applied to an insert cutting tool using a WC-based cemented carbide as a tool base will be described. Even when the above-mentioned TiCN-based cermet or the like is used as the tool base, a drill, an end mill or the like can be used as the tool. The same applies when applied to.

First, as raw material powders, Co powder, VC powder, Cr ₃ C ₂ powder, TiC powder, TaC powder, NbC powder, and WC powder are prepared, and these raw material powders are blended into the blending composition shown in Table 1, and further. Wax was added, wet-mixed in a ball mill for 72 hours, dried under reduced pressure, and press-molded at a pressure of 100 MPa. Next, these powder compacts were sintered and processed to have a predetermined size to prepare tool bases 1 to 3 made of WC-based cemented carbide having an insert shape of ISO standard SEEN1203AFTN1.

Next, in order to form a hard film layer using the AIP device, the tool substrates 1 to 3 are ultrasonically cleaned in acetone, dried, and separated from the central axis on the rotary table in the AIP device by a predetermined distance in the radial direction. It was attached to the position along the outer circumference. Further, as the cathode electrode (evaporation source), a Ti—Al—M alloy target having a predetermined composition and a Cr—Al—M alloy target having a predetermined composition were arranged. The Ti—Al—M alloy target and the Cr—Al—M alloy target having a predetermined composition are targets having a composition corresponding to the average composition of the target (TiAlM) N film and (CrAlM) N film, respectively.

Subsequently, the inside of the AIP device was heated to 500 ° C. using a heater while keeping the inside of the AIP device in ^{a vacuum of 10-2 Pa or less.} Then, an argon gas atmosphere of 0.5 to 2.0 Pa was set, and a DC bias voltage of −200 to −1000 V was applied to the tool substrate rotating while rotating on the rotary table. As a result, the surface of the tool substrate was bombarded with argon ions or metal ions for 5 to 120 minutes. Here, the metal ion is generated by passing a predetermined current in the range of 80 to 240 A between the cathode electrode (evaporation source) made of the metal target and the anode electrode to cause arc discharge.

Nitrogen gas and Ar gas having a partial pressure in the range of 0.1 to 5.0 Pa shown in Tables 2 and 3 are introduced into the AIP apparatus for a predetermined time as reaction gases. Then, the tool substrate, which is also maintained at the furnace temperature shown in Tables 2 and 3 and rotates while rotating on the rotary table, has a predetermined DC bias within the range of -30 to -150 V shown in Tables 2 and 3. Within the range of 80 to 240A shown in Tables 2 and 3 between the cathode electrode (evaporation source) and the anode electrode, which are made of a Ti—Al—M alloy target or a Cr—Al—M alloy target and a voltage is applied. 1 to 9 and 11 to 19 (10 is a missing number) of the covering tools of the present invention (hereinafter referred to as "example tools") shown in Tables 4 and 5 by passing a predetermined current of the above to generate an arc discharge. Was produced.

The "interface region N ₂ gas supply time (minutes)" _{in Tables 2 and 3 means the "N 2} gas supply time (minutes) when the interface region is formed". From the initial pressure, N ₂ and Ar volume% _{, over the time of "interface region N 2} gas supply time (minutes)", the pressure _{is linearly changed to the end value pressure, N 2} and Ar volume%, and then. The film formation was completed with this end value.

On the other hand, for comparison, the (TiAlM) N film was deposited on the tool substrates 1 to 3 using the same AIP device as described above, and the (CrAlM) N film was deposited under the conditions shown in Table 3. The film tools of Comparative Examples shown in Tables 6 and 7 (hereinafter referred to as "Comparative Example Tools") 1 to 3 and 11 to 13 (4 to 10 are missing numbers) were prepared.

The average layer thickness, average composition, and N content of the interface region of the hard coating layer having (TiAlM) N film and (CrAlM) N film are determined by scanning electron microscope (SEM), transmission electron microscope (TEM), and energy. It was determined by cross-sectional observation using distributed X-ray spectroscopy (EDS). The observation cross section is a vertical cross section of the hard film layer perpendicular to the surface of the tool substrate, has a width of 10 μm in the direction parallel to the surface of the tool substrate, and is set to include the entire thickness region of the hard film layer. It was a thing.

Specifically, as for the average layer thickness, the observed cross section was enlarged 5000 times, and the layer thickness at 5 points was obtained to calculate the average layer thickness. The average composition and the N content in the interface region were determined by performing five EDS line analyzes at equal intervals in the layer thickness direction. That is, five TEM-EDS line analyzes were performed from the tool base side to the tool surface side at equal intervals of 100 μm.

Then, only the atoms constituting the hard coating layer of (Ti, Al, M, N) or (Cr, Al, M, N) begin to be detected, and the surface of the tool substrate having an N content of 10 to 30 atomic%. The point 0.5 nm from the point closest to the tool base surface side is the position on the tool base side, and the point 0.5 nm toward the tool base side is the tool surface side rather than the point where the N content does not increase any more. The position was set to. The positions of these points were measured from the surface of the tool substrate. In Tables 4 to 7, the contents of N at the position on the tool base side and the position on the tool surface side are shown as average values of the five analyzes, respectively. The average layer thickness of the interface region is the distance between the position on the tool substrate side and the position on the tool surface side plus 1 nm.

Next, high-speed cutting tests on alloy steel, cast iron, carbon steel, and stainless steel were performed on Examples Tools 1 to 9, 11 to 19 and Comparative Examples Tools 1 to 3 to 11 to 13 under the following conditions. carried out.

Cutting test A: (Tools 1 to 9 of this example, Tools 1 to 3 of Comparative Example)
Work material: JIS / SCM430 (HB250) round bar Cutting speed: 220 m / min.
Notch: 0.3 mm
Feed: 0.25 mm / rev.
Cutting time: High-speed cutting test of alloy steel under the condition of 5 minutes (normal cutting speed and feed are 165 m / min. And 0.20 mm / rev, respectively).
The results of cutting test A are shown in Table 8.

Cutting test B: (Tools 1 to 9 of this example, Tools 1 to 3 of Comparative Example)
Work material: JIS / FCD600 round bar Cutting speed: 220 m / min.
Notch: 0.25 mm
Feed: 0.21 mm / rev.
Cutting time: High-speed cutting test of cast iron under the condition of 5 minutes (normal cutting speed and feed are 145 m / min. And 0.2 mm / rev, respectively).
The results of cutting test B are shown in Table 9.

Cutting test C: (Tools 11 to 19 of this example, tools 11 to 13 of comparative example)
Work material: JIS / S55C (HB250) round bar Cutting speed: 220 m / min.
Notch: 0.2 mm
Feed: 0.24 mm / rev.
Cutting time: 5 minutes,
Continuous high-speed high-feed cutting machining test of carbon steel under the conditions of (normal cutting speed and feed are 145 m / min. And 0.25 mm / rev, respectively).
The results of cutting test C are shown in Table 10.

Cutting test D: (Tools 11 to 19 of this example, tools 11 to 13 of comparative example)
Work material: JIS / SUS304 (HB180) round bar Cutting speed: 140 m / min.
Notch: 2.0 mm
Feed: 0.33 mm / rev.
Cutting time: Wet continuous high feed cutting test of stainless steel under the condition of 9 minutes (cutting condition B) (normal cutting speed and feed are 120 m / min. And 0.3 mm / rev, respectively).
The results of the cutting test D are shown in Table 11.

According to the results of Tables 8 to 11, for the tools 1 to 9, any of the cutting tests A and B, and for the tools 11 to 19, any of the cutting tests C and D, chipping, peeling, etc. It can be seen that no abnormal damage occurs and that both chipping resistance and wear resistance are excellent. On the other hand, for Comparative Examples Tools 1 to 3, chipping occurred or flank wear occurred in any of the cutting tests A and B, and for Comparative Examples Tools 11 to 13 in any of the cutting tests C and D. It is clear that the life of the product reaches the end of its life in a short time.

The disclosed embodiments are merely exemplary in all respects and are not restrictive. The scope of the present invention is indicated by the scope of claims rather than the embodiment described above, and is intended to include meaning equivalent to the scope of claims and all modifications within the scope.

1: Tool base 2: Interface region 3: Hard film 4: Hard film layer

Claims (2)

A surface-coated cutting tool having a hard film layer containing a composite nitride film having an average layer thickness of 0.5 to 10.0 μm on the surface of the tool substrate.
It said composite nitride film is expressed by the _formula when expressed in _{(Ti 1-x-y Al} x M y) N z, 0.35 ≦ x ≦ 0.80,0.00 ≦ y ≦ 0.20,0 .20 ≦ (1-xy) ≦ 0.65, 0.90 ≦ z ≦ 1.10 (where x, y, z are atomic ratios, M is atoms of groups 4 to 6 of the periodic table of IUPAC, It has an average composition that satisfies at least one of Y, Si, La, and Ce), and has an average composition.
In the interface region of the hard coating layer having an average thickness in the range of 5 to 100 nm from the surface of the tool substrate to the tool surface, the content ratio of N to the total amount of Ti, Al, M and N is the above. The surface side of the tool substrate is 10 to 30 atomic%, and the amount increases from the surface of the tool substrate toward the tool surface in the interface region.
A surface coating cutting tool characterized by. A surface-coated cutting tool having a hard film layer containing a composite nitride film having an average layer thickness of 0.5 to 10.0 μm on the surface of the tool substrate.
It said composite nitride film is expressed by the _formula when expressed in _{(Cr 1-x-y Al} x M y) N z, 0.35 ≦ x ≦ 0.80,0.00 ≦ y ≦ 0.20,0 .20 ≦ (1-xy) ≦ 0.65, 0.90 ≦ z ≦ 1.10 (where x, y, z are atomic ratios, M is atoms of groups 4 to 6 of the periodic table of IUPAC, It has an average composition that satisfies at least one of Y, Si, La, and Ce), and has an average composition.
In the interface region of the hard coating layer having an average thickness in the range of 5 to 100 nm from the surface of the tool substrate to the tool surface, the content ratio of N to the total amount of Cr, Al, M and N is the above. The surface side of the tool substrate is 10 to 30 atomic%, and the amount increases from the surface of the tool substrate toward the tool surface in the interface region.
A surface coating cutting tool characterized by.

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