WO2016068122A1 - Surface-coated cutting tool - Google Patents

Abstract

A coated tool in which a hard coating layer comprises a composite nitride or composite carbonitride layer (2) represented by the compositional formula: (Ti_1-x-yAl_xMe_y)(C_zN_1-z) (wherein Me represents at least one element selected from Si, Zr, B, V and Cr), wherein the average Al content ratio X_avg, the average Me content ratio Y_avg and the average C content ratio Z_avg meet the requirements represented by the formulae 0.60 ≤ X_avg, 0.005 ≤ Y_avg ≤ 0.10, 0 ≤ Z_avg ≤ 0.005 and 0.605 ≤ X_avg + Y_avg ≤ 0.95, crystal grains that constitute the composite nitride or composite carbonitride layer (2) contain crystal grains each having a cubic structure, and a specific periodic compositional change among Ti, Al and Me occurs in the crystal grains each having a cubic structure.

Description

Surface coated cutting tool

The present invention is a high-speed intermittent cutting process that involves high heat generation of alloy steel and the like, and an impact load is applied to the cutting edge, and the hard coating layer has excellent chipping resistance, so that it can be used for a long time. The present invention relates to a surface-coated cutting tool (hereinafter referred to as a coated tool) that exhibits excellent cutting performance.
This application claims priority based on Japanese Patent Application No. 2014-219207 filed in Japan on October 28, 2014 and Japanese Patent Application No. 2015-208164 filed in Japan on October 22, 2015. The contents are incorporated herein.

Conventionally, generally composed of tungsten carbide (hereinafter referred to as WC) based cemented carbide, titanium carbonitride (hereinafter referred to as TiCN) based cermet or cubic boron nitride (hereinafter referred to as cBN) based ultra high pressure sintered body A coated tool is known in which a Ti—Al-based composite nitride layer is formed by physical vapor deposition as a hard coating layer on the surface of a substrate (hereinafter collectively referred to as “substrate”). It is known that it exhibits excellent wear resistance.
However, the conventional coated tool formed with the Ti—Al composite nitride layer is relatively excellent in wear resistance, but it tends to cause abnormal wear such as chipping when used under high-speed intermittent cutting conditions. Accordingly, various proposals have been made for improving the hard coating layer.

For example, in Patent Document 1, a TiCN layer and an Al ₂ O ₃ layer are used as an inner layer, and a cubic crystal structure (Ti _1-x) including a cubic crystal structure or a hexagonal crystal structure is formed thereon by chemical vapor deposition. Al _x ) N layer (where x is 0.65 to 0.9) is coated as an outer layer, and by applying compressive stress of 100 to 1100 MPa to the outer layer, the heat resistance and fatigue strength of the coated tool are improved. It has been proposed to do.

Patent Document 2 discloses a surface-coated cutting tool including a tool base and a hard coating layer formed on the base, and the hard coating layer includes one or both of Al and Cr elements. A compound composed of at least one element selected from the group consisting of Group 4a, 5a, 6a group elements and Si, and at least one element selected from the group consisting of carbon, nitrogen, oxygen and boron And chlorine are disclosed to dramatically improve the wear resistance and oxidation resistance of the hard coating layer.

Patent Document 3 discloses that chemical vapor deposition is performed in a mixed reaction gas of TiCl ₄ , AlCl ₃ , and NH ₃ in a temperature range of 650 to 900 ° C., so that the value of the Al content ratio x is 0.65 to Although it is described that a (Ti _1-x Al _x ) N layer having a thickness of 0.95 can be formed by vapor deposition, this reference further describes an Al ₂ O ₃ layer on the (Ti _1-x Al _x ) N layer. In order to enhance the heat insulation effect, and by forming a (Ti _1-x Al _x ) N layer in which the value of x is increased from 0.65 to 0.95, cutting performance is improved. There is no disclosure up to the point of how this will be affected.

Japanese National Table 2011-513594 (A) Japanese Unexamined Patent Publication No. 2006-82207 (A) Japan Special Table 2011-516722 Publication (A)

In recent years, there has been a strong demand for energy saving and energy saving in cutting, and along with this, cutting tends to be faster and more efficient, and the coated tool has even more chipping resistance, chipping resistance, Abnormal damage resistance such as peel resistance is required, and excellent wear resistance over long-term use is required.
However, although the coated tool described in Patent Document 1 has a predetermined hardness and excellent wear resistance, it is inferior in toughness, so when it is used for high-speed intermittent cutting of alloy steel, etc. However, there is a problem that abnormal damage such as chipping, chipping and peeling is likely to occur, and it cannot be said that satisfactory cutting performance is exhibited.
Further, the coated tool described in Patent Document 2 is intended to improve wear resistance and oxidation resistance characteristics, but chipping resistance under cutting conditions involving impact such as high-speed interrupted cutting. There was a problem that was not enough.
On the other hand, for the (Ti _1-x Al _x ) N layer formed by chemical vapor deposition described in Patent Document 3, the Al content ratio x can be increased, and a cubic crystal structure is formed. Therefore, although a hard coating layer having a predetermined hardness and excellent wear resistance can be obtained, there is a problem that the adhesion strength with the substrate is not sufficient and the toughness is inferior.

Therefore, the technical problem to be solved by the present invention, that is, the purpose of the present invention is to provide excellent toughness even when subjected to high-speed interrupted cutting such as alloy steel, carbon steel, cast iron, etc. It is an object of the present invention to provide a coated tool that exhibits excellent chipping resistance and wear resistance over use.

In view of the above, the present inventors have at least a composite nitride or composite carbonitride of Ti and Al (hereinafter referred to as “(Ti, Al) (C, N)” or “(Ti _1-x Al _x ) ( _{CyN 1-y} ) ”), a hard coating layer containing a hard coating layer formed by chemical vapor deposition. Results of extensive research to improve chipping resistance and wear resistance. The following findings were obtained.

That is, the conventional hard coating layer including at least one (Ti _1-x Al _x ) (C _y N _1-y ) layer and having a predetermined average layer thickness is (Ti _1-x Al _x ) ( When the C _y N _1-y ) layer is formed in a columnar shape in the direction perpendicular to the tool base, it has high wear resistance. On the other _hand, it reduces the toughness of _{(Ti 1-x} Al _x) as anisotropy (C _{y N 1-y)} layer is high _{(Ti 1-x Al x)} (C y N 1-y) layer, As a result, chipping resistance and chipping resistance are reduced, and sufficient wear resistance cannot be exhibited over a long period of use, and the tool life cannot be said to be satisfactory.
Therefore, the present inventors have conducted intensive studies on the (Ti _1-x Al _x ) (C _y N _1-y ) layer constituting the hard coating layer, and found that the hard coating layer had Si, Zr, B, V, Cr. (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer mainly containing a NaCl type face centered cubic material. The cubic crystal grains are distorted by a completely new idea that they are composed of crystal grains having a structure and that periodic concentration changes (content ratios) of Ti, Al, and Me are formed in the cubic crystal phase. The inventors have succeeded in improving the hardness and toughness, and as a result, have found a novel finding that the chipping resistance and fracture resistance of the hard coating layer can be improved.

Specifically, the hard coating layer is a composite nitride of Ti, Al, and Me (where Me is a kind of element selected from Si, Zr, B, V, and Cr) having an average layer thickness of 1 to 20 μm. Alternatively, when it includes at least a composite carbonitride layer and is represented by a composition formula: (Ti _1-xy Al _x Me _y ) (C _z N _1-z ), it occupies the total amount of Ti of Al and Al and Me. Average content ratio X _avg and average content ratio Y _avg in the total amount of Ti, Al, and Me in Me and average content ratio Z _avg in the total amount of C and N in C (where X _avg , Y _avg , Z _avg Are atomic ratios) of 0.60 ≦ X _avg , 0.005 ≦ Y _avg ≦ 0.10, 0 ≦ Z _avg ≦ 0.005, 0.605 ≦ X _avg + Y _avg ≦ 0.95, respectively. Satisfied, said composite nitride or composite carbonitride The layer includes grains having a NaCl-type face-centered cubic structure (or further including grains having a wurtzite-type hexagonal structure), and the NaCl-type face in the composite nitride or composite carbonitride layer. When the crystal orientation of Ti / Al / Me composite nitride or composite carbonitride crystal grains having a centered cubic structure is analyzed from the longitudinal section direction using an electron beam backscattering diffractometer, the normal of the tool base surface An inclination angle formed by a normal line of the {110} plane which is a crystal plane of the crystal grain with respect to the direction is measured, and an inclination angle within a range of 0 to 45 degrees with respect to the normal direction is set to 0. When the slope angle distribution is determined by counting the frequencies existing in each section by dividing the pitch every 25 degrees, the highest peak exists in the slope angle section within the range of 0 to 12 degrees, and the above 0 to The sum of the frequencies existing in the range of 12 degrees is the inclination. Shows the percentage of more than 35% of the total power in the frequency distribution, in the crystal grains of a face-centered cubic structure of the NaCl type, composition _{formula: (Ti 1-x-y} Al x Me y) (C z N 1-z ) There is a periodic concentration change (content ratio) of Ti, Al, and Me (that is, x, y, z are not constant values but values that change periodically), and the Al content ratio x periodically varying x average value X _max of the maximum value of the value _of addition, when the average value of the minimum value of the periodically value varying x in proportion x of Al was set to X _min, X _max and _X difference Δx of _min is 0.03-0.25, the composite nitride or composite carbonitride layer of Ti and Al and Me periodic density variation exists NaCl type face-centered cubic structure In the crystal grains having a period of 3 to 1 along the normal direction of the tool base surface By being 00 nm, the crystal grains having the NaCl-type face-centered cubic structure are distorted, and compared with the conventional hard coating layer, (Ti _1-xy Al _x Me _y ) (C _z N _{1 -Z} ) It has been found that the hardness and toughness of the layer are increased, and as a result, chipping resistance and fracture resistance are improved, and excellent wear resistance is exhibited over a long period of time.

The (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer having the above-described configuration is, for example, the following chemical vapor deposition that periodically changes the reaction gas composition on the tool base surface. The film can be formed by the method.
The chemical vapor deposition reactor used includes a gas group A composed of NH ₃ , N ₂ and H ₂ , TiCl ₄ , Al (CH ₃ ) ₃ , AlCl ₃ , MeCl _n (Me chloride), NH ₃ , N _2. , H ₂ gas groups B are supplied into the reactor from respective separate gas supply pipes, and the gas group A and the gas group B are supplied into the reactor, for example, at regular time intervals. The gas is supplied such that the gas flows for a time shorter than the period, and the gas supply of the gas group A and the gas group B causes a phase difference of a time shorter than the gas supply time so that the reaction gas composition on the tool base surface is set. , (I) gas group A, (II) mixed gas of gas group A and gas group B, and (III) gas group B can be changed with time. Incidentally, in the present invention, it is not necessary to introduce a long exhaust process intended for strict gas replacement. Therefore, as a gas supply method, for example, by rotating the gas supply port, rotating the tool base, or reciprocating the tool base, the reaction gas composition on the surface of the tool base is changed to (I) Gas group A This can also be realized by temporally changing to a mixed gas mainly composed of (II) a mixed gas composed of gas group A and gas group B, and (III) a mixed gas mainly composed of gas group B.
The reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) on the surface of the tool base is, for example, NH ₃ : 3.5 to 4.0% as the gas group A, H ₂ : 65 to 75. %, As gas group B, AlCl ₃ : 0.6 to 0.9%, TiCl ₄ : 0.2 to 0.3%, MeCl _n (Me chloride): 0.1 to 0.2%, Al ( CH ₃ ) ₃ : 0 to 0.5%, N ₂ : 0.0 to 12.0%, H ₂ : remaining, reaction atmosphere pressure: 4.5 to 5.0 kPa, reaction atmosphere temperature: 700 to 900 ° C, With a supply period of 1 to 5 seconds, a gas supply time per cycle of 0.15 to 0.25 seconds, and a phase difference between gas supply A and gas supply B of 0.10 to 0.20 seconds, a thermal CVD method is performed for a predetermined time. As a result, a (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer having a predetermined target layer thickness is formed. The

As described above, the gas group A and the gas group B are supplied so as to have a difference in time to reach the tool base surface, and the nitrogen source gas in the gas group A is set to NH ₃ : 3.5 to 4.0%. , AlCl ₃ : 0.6 to 0.9%, TiCl ₄ : 0.2 to 0.3%, MeCl _n (Me chloride): 0.1 -0.2%, Al (CH ₃ ) ₃ : Set to 0-0.5%, local distortion of the crystal lattice due to local compositional irregularities, dislocations and point defects in the crystal grains In addition, the degree of {110} orientation of the crystal grains on the tool base surface side and the film surface side can be changed. As a result, it has been found that toughness is dramatically improved while maintaining wear resistance. As a result, especially when used for high-speed intermittent cutting of alloy steel, etc., where the chipping resistance and chipping resistance are improved, and the intermittent and impact loads are applied to the cutting edge, It has been found that excellent cutting performance can be exhibited over use.

This invention is made | formed based on the said knowledge, Comprising: It has the following aspects.
(1) Surface-coated cutting in which a hard coating layer is formed on the surface of a tool base composed of any of tungsten carbide-based cemented carbide, titanium carbonitride-based cermet, or cubic boron nitride-based ultrahigh-pressure sintered body In the tool
(A) The hard coating layer is a composite nitride of Ti, Al, and Me (where Me is a kind of element selected from Si, Zr, B, V, and Cr) having an average layer thickness of 1 to 20 μm or When at least the composite carbonitride layer is included and expressed by the composition formula: (Ti _1-xy Al _x Me _y ) (C _z N _1-z ), the Ti of the composite nitride or the composite carbonitride layer The average content ratio X _avg in the total amount of Al and Me and Me, the average content ratio Y _avg in the total amount of Ti, Al and Me in Me and the average content ratio Z _avg in the total amount of C and N in C , X _avg , Y _avg , and Z _avg are all atomic ratios) are 0.60 ≦ X _avg , 0.005 ≦ Y _avg ≦ 0.10, 0 ≦ Z _avg ≦ 0.005, 0.605 ≦ X _avg + Y _avg ≦ 0.95 is satisfied,
(B) The composite nitride or composite carbonitride layer includes at least a composite nitride or composite carbonitride phase of Ti, Al, and Me having a NaCl type face-centered cubic structure,
(C) Electron beam backscattering of crystal orientation of Ti, Al, and Me composite nitride or composite carbonitride crystal grains having NaCl-type face-centered cubic structure in the composite nitride or composite carbonitride layer When analyzing from the longitudinal section direction using a diffractometer, the inclination angle formed by the normal of the {110} plane, which is the crystal plane of the crystal grain, with respect to the normal direction of the tool base surface is measured, When the inclination angle in the range of 0 to 45 degrees with respect to the line direction is divided into pitches of 0.25 degrees and the frequencies existing in each division are totaled to obtain the inclination angle number distribution, 0 to 12 The highest peak exists in the inclination angle section within the range of degrees, and the total of the frequencies existing in the range of 0 to 12 degrees indicates a ratio of 35% or more of the entire degrees in the inclination angle frequency distribution,
(D) Further, in the crystal grains of the composite nitride or composite carbonitride of Ti, Al, and Me having the NaCl type face-centered cubic structure, the composition formula: (Ti _1-xy Al _x Me _y ) There is a periodic concentration change of Ti, Al, and Me in (C _z N _1-z ), and the average value of the maximum value of the periodically changing x value of the Al content ratio x is expressed as X _max , If the average value of the minimum value of the periodically value varying x in proportion x of Al was set to _{X min,} the difference Δx of _{X max} and _{X min} is 0.03-0.25,
(E) In a crystal grain having a NaCl-type face-centered cubic structure in which a periodic concentration change of Ti, Al, and Me in the composite nitride or composite carbonitride layer exists, the normal direction of the tool base surface A surface-coated cutting tool, wherein the period along the axis is 3 to 100 nm.
(2) In a crystal grain having a NaCl-type face-centered cubic structure in which a periodic concentration change of Ti, Al, and Me in the composite nitride or composite carbonitride layer exists, the periodicity of Ti, Al, and Me There is a significant concentration change along one of the equivalent crystal orientations represented by <001> of the cubic crystal grains, and the period along the orientation is 3 to 100 nm, which is orthogonal to the orientation. The surface-coated cutting tool according to (1), wherein the maximum value ΔXo of the change amount of the Al content ratio x in the plane is 0.01 or less.
(3) In crystal grains having a NaCl-type face-centered cubic structure in which periodic concentration changes of Ti, Al, and Me in the composite nitride or composite carbonitride layer exist,
(A) A periodic concentration change of Ti, Al, and Me exists along one of the equivalent crystal orientations represented by <001> of the cubic crystal grains, and the orientation is defined as an orientation d _A Then, the azimuth _d cycle along the _a is 3 ~ 100 nm, orientation _d maximum value of the variation in the content ratio x of Al in a plane perpendicular to the _a DerutaXod _a region a is 0.01 or less,
Periodic density variation of (b) Ti, Al and Me is present along one of the orientation of the crystal orientation of the equivalent represented by <001> cubic crystal grains perpendicular to the orientation d _A, When the azimuth and azimuth _{d B,} a period is 3 ~ 100 nm along the direction _{d B,} the maximum value DerutaXod _B of variation of the proportion x of Al in a plane perpendicular to the direction _{d B} 0.01 Region B, which is
The region A and the region B exist in crystal grains, and the boundary between the region A and the region B is formed on one of the equivalent crystal planes represented by {110}. The surface-coated cutting tool according to (1).
(4) For the composite nitride or composite carbonitride layer, the lattice constant a of the crystal grains having the NaCl type face centered cubic structure is obtained from X-ray diffraction, and the crystal grains having the NaCl type face centered cubic structure are obtained. The lattice constant a satisfies the relationship of 0.05a _TiN + 0.95a _AlN ≦ a ≦ 0.4a _TiN + 0.6a _AlN with respect to the lattice constant a _TiN of cubic _TiN and the lattice constant a _AlN of cubic AlN. The surface-coated cutting tool according to any one of (1) to (3), characterized in that:
(5) When the composite nitride or the composite carbonitride layer is observed from the longitudinal cross-sectional direction of the layer, the composite nitride of Ti, Al, and Me having a NaCl-type face-centered cubic structure in the layer or (1) to (4) above, wherein the composite carbonitride has a columnar structure having an average grain width W of 0.1 to 2.0 μm and an average aspect ratio A of 2 to 10 The surface-coated cutting tool according to any one of the above.
(6) The composite nitride or composite carbonitride layer has an area ratio of Ti, Al, and Me composite nitride or composite carbonitride having an NaCl type face-centered cubic structure of 70 area% or more. The surface-coated cutting tool according to any one of (1) to (5), which is characterized in that
(7) A tool base composed of any one of the tungsten carbide-based cemented carbide, titanium carbonitride-based cermet, or cubic boron nitride-based ultrahigh-pressure sintered body, and a composite nitride or composite carbon of Ti, Al, and Me. Between the nitride layers, one or two or more of a Ti carbide layer, a nitride layer, a carbonitride layer, a carbonate layer and a carbonitride oxide layer, and 0.1 to 20 μm The surface-coated cutting tool according to any one of (1) to (6), wherein a lower layer including a Ti compound layer having a total average layer thickness is present.
(8) The above (1) to (7), wherein an upper layer including at least an aluminum oxide layer is present on the composite nitride or composite carbonitride layer at a total average layer thickness of 1 to 25 μm. The surface-coated cutting tool according to any one of the above.
(9) The composite nitride or the composite carbonitride layer is formed by a chemical vapor deposition method containing at least trimethylaluminum as a reactive gas component. The manufacturing method of the surface coating cutting tool as described in any one of 1).
In addition, the hard coating layer (hereinafter referred to as “hard coating layer of the present invention”) in the surface-coated cutting tool which is one embodiment of the present invention is essentially the above-described composite nitride or composite carbonitride layer. Further, the combined effect of the composite nitride or the composite carbonitride layer can be obtained by using it together with the conventionally known lower layer of (7) and the upper layer of (8). Needless to say, even better characteristics can be created.

The present invention will be described in detail below.

Average layer thickness of the composite nitride or composite carbonitride layer 2 constituting the hard coating layer:
In FIG. 1, the cross-sectional schematic diagram of the composite nitride or composite carbonitride layer 2 of Ti, Al, and Me which comprises the hard coating layer of this invention is shown.
The hard coating layer of the present invention has a chemical vapor-deposited composition formula: (Ti _1-xy Al _x Me _y ) (C _z N _1-z ), a composite nitride or composite of Ti, Al, and Me. At least the carbonitride layer 2 is included. The composite nitride or composite carbonitride layer 2 has high hardness and excellent wear resistance, but the effect is particularly remarkable when the average layer thickness is 1 to 20 μm. The reason is that if the average layer thickness is less than 1 μm, the layer thickness is so thin that sufficient wear resistance over a long period of use cannot be ensured. On the other hand, if the average layer thickness exceeds 20 μm, Ti and The crystal grains of the composite nitride or composite carbonitride layer 2 of Al and Me are likely to be coarsened, and chipping is likely to occur. Therefore, the average layer thickness is set to 1 to 20 μm.
Although it is not particularly essential, a more preferable average layer thickness is 3 to 15 μm. Further preferably, the average layer thickness is 4 to 10 μm.

Composition of composite nitride or composite carbonitride layer 2 constituting hard coating layer:
The composite nitride or composite carbonitride layer 2 constituting the hard coating layer of the present invention is represented by the composition formula: (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) (however, , Me is a kind of element selected from Si, Zr, B, V, and Cr), the average content ratio X _avg in the total amount of Ti, Al, and Me of Al, and the combination of Ti, Al, and Me of Me The average content ratio Y _{avg in the} amount and the average content ratio Z _avg in the total amount of C and C in C, where X _avg , Y _avg , and Z _avg are all atomic ratios) are 0.60 ≦ X _avg , 0.005 ≦ Y _avg ≦ 0.10, 0 ≦ Z _avg ≦ 0.005, 0.605 ≦ X _avg + Y _avg ≦ 0.95.
The reason is that when the average content ratio X _avg of Al is less than 0.60, the hardness of the composite nitride of Ti and Al and Me or the composite carbonitride layer 2 is inferior. When it is used, the wear resistance is not sufficient.
Further, when the average content ratio Y _{avg of} Me is less than 0.005, the composite nitride of Ti, Al, and Me or the composite carbonitride layer 2 is inferior in hardness, so that it is used for high-speed intermittent cutting of alloy steel and the like. In such a case, the wear resistance is not sufficient. On the other hand, if it exceeds 0.10, the toughness of the composite nitride of Ti, Al, and Me or the composite carbonitride layer 2 decreases due to the segregation of Me to the grain boundary, etc., and is used for high-speed intermittent cutting of alloy steel and the like. In some cases, the chipping resistance is not sufficient. Therefore, the average content ratio Y _avg of Me was determined as 0.005 ≦ Y _avg ≦ 0.10.
On the other hand, when the sum X _avg + Y _avg of the average content ratio X _{avg of} Al and the average content ratio Y _{avg of} Me is less than 0.605, the composite nitride or composite carbonitride layer 2 of Ti, Al, and Me Since it is inferior in hardness, when it is subjected to high-speed interrupted cutting of alloy steel or the like, the wear resistance is not sufficient. Inviting, chipping resistance decreases. Therefore, the sum X _avg + Y _avg of the average content ratio X _{avg of} Al and the average content ratio Y _{avg of} Me was determined as 0.605 ≦ X _avg + Y _avg ≦ 0.95.
Here, as a specific component of Me, a kind of element selected from Si, Zr, B, V, and Cr is used.
When Si component or B component is used so that Y _avg is 0.005 or more as Me, the hardness of the composite nitride or composite carbonitride layer 2 is improved, so that the wear resistance is improved. The Zr component has the effect of strengthening the grain boundary, and the V component improves toughness, so that the chipping resistance can be further improved, and the Cr component improves oxidation resistance. Therefore, a longer tool life is expected. However, in any component, when the average content ratio Y _avg exceeds 0.10, the average content ratios of the Al component and the Ti component are relatively decreased, so that the wear resistance or chipping resistance tends to decrease. Therefore, it must be avoided that the average content ratio is such that Y _avg exceeds 0.10.
Further, when the average content ratio (atomic ratio) Z _avg of C contained in the composite nitride or composite carbonitride layer 2 is a minute amount in the range of 0 ≦ Z _avg ≦ 0.005, the composite nitride or composite carbon The adhesion between the nitride layer 2 and the tool base 3 or the lower layer is improved and the lubricity is improved to reduce the impact during cutting. As a result, the resistance of the composite nitride or the composite carbonitride layer 2 is improved. Defectability and chipping resistance are improved. On the other hand, if the average content ratio C _{avg of} C deviates from the range of 0 ≦ Z _avg ≦ 0.005, the toughness of the composite nitride or composite carbonitride layer 2 is lowered, so that the chipping resistance and chipping resistance are reversed. Since it falls, it is not preferable. Therefore, the average content ratio Z _avg of C was determined as 0 ≦ Z _avg ≦ 0.005.
Although not particularly essential, more preferable X _avg , Y _avg and Z _avg are 0.70 ≦ X _avg ≦ 0.85, 0.01 ≦ Y _avg ≦ 0.05, and 0 ≦ Z _avg ≦ 0, respectively. 0.003, 0.7 ≦ X _avg + Y _avg ≦ 0.90.

It has a NaCl-type face-centered cubic structure in the composite nitride or composite carbonitride layer 2 ((Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer) of Ti, Al, and Me Inclination angle number distribution about {110} plane which is a crystal plane of each crystal grain:
For the (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer of the present invention, the individual crystal grains having a NaCl-type face-centered cubic structure using an electron beam backscattering diffractometer. When the crystal orientation is analyzed from the longitudinal section direction, the normal line of the {110} plane which is the crystal plane of the crystal grain with respect to the normal line 5 of the tool base surface (the direction perpendicular to the tool base surface 4 in the cross-section polished surface) 6 is measured (see Fig. 2A and Fig. 2B), and the tilt angle within the range of 0 to 45 degrees with respect to the normal direction is classified for each pitch of 0.25 degrees. When the frequencies existing in each section are tabulated, the highest peak is present in the tilt angle section within the range of 0 to 12 degrees, and the total of the frequencies existing in the range of 0 to 12 degrees is the slope. Inclination angle that is 35% or more of the total frequency in the angle distribution In the case of showing a number distribution form, the hard coating layer composed of the composite nitride or composite carbonitride layer 2 of Ti, Al, and Me has high hardness while maintaining the NaCl type face centered cubic structure, In addition, the adhesiveness between the hard coating layer and the substrate is dramatically improved by the above-described inclination angle number distribution form.
Therefore, even when such a coated tool is used for, for example, high-speed intermittent cutting of alloy steel, the occurrence of chipping, chipping, peeling and the like is suppressed, and excellent wear resistance is exhibited.
FIG. 3A and FIG. 3B are graphs showing an example of the inclination angle number distribution obtained by measuring the crystal grains having a cubic structure, which is one embodiment of the present invention and a comparison, by the above method.

Crystal grains having a NaCl-type face-centered cubic structure (hereinafter simply referred to as “cubic crystal”) constituting the composite nitride or composite carbonitride layer 2:
When each cubic crystal grain in the composite nitride or composite carbonitride layer is observed and measured from the side of the coating cross section perpendicular to the tool base surface 4, the grain width in the direction parallel to the tool base surface 4 is expressed as w. Further, the grain length in the direction perpendicular to the tool substrate surface 4 is l, the ratio l / w between w and l is the aspect ratio a of each crystal grain, and the aspect ratio obtained for each crystal grain When the average value of a is the average aspect ratio A, and the average value of the particle width w obtained for each crystal grain is the average particle width W, the average particle width W is 0.1 to 2.0 μm and the average aspect ratio A is It is desirable to control so as to satisfy 2 to 10.
When this condition is satisfied, the cubic crystal grains constituting the composite nitride or composite carbonitride layer 2 have a columnar structure and exhibit excellent wear resistance. On the other hand, when the average aspect ratio A is less than 2, it becomes difficult to form a periodic distribution (concentration change, content ratio change) of the composition, which is a feature of the present invention, in the crystal grains of the NaCl type face-centered cubic structure. A columnar crystal exceeding 10 is not preferable because cracks are likely to grow along a plane along a periodic distribution of the composition in the cubic crystal phase, which is a feature of the present invention, and a plurality of grain boundaries. Further, when the average particle width W is less than 0.1 μm, the wear resistance is lowered, and when it exceeds 2.0 μm, the toughness is lowered. Therefore, the average grain width W of the cubic crystal grains constituting the composite nitride or composite carbonitride layer 2 is preferably 0.1 to 2.0 μm.
Although not particularly essential, the more preferable average aspect ratio and average particle width W are 4 to 7 and 0.7 to 1.5 μm, respectively.

Changes in concentration of Ti, Al, and Me existing in crystal grains having a cubic crystal structure:
FIG. 4 shows a composite nitride layer or composite carbonitride layer of Ti, Al, and Me contained in the hard coating layer of the present invention (hereinafter referred to as “composite nitride layer or composite carbonitride of Ti, Al, and Me of the present invention”). A crystal grain having a cubic crystal structure), and a periodic concentration change of Ti, Al, and Me is one of the equivalent crystal orientations represented by <001> of the cubic crystal grain. It is shown as a schematic diagram that the change in the Al content ratio x is small in a plane that exists along the direction and is orthogonal to the direction.
FIG. 5 shows a cubic crystal structure in which a periodic concentration change of Ti, Al, and Me exists in the cross section of the composite nitride layer or composite carbonitride layer of Ti, Al, and Me of the present invention. An example of a graph of periodic concentration change x of Al with respect to the total of Ti, Al, and Me as a result of performing a line analysis by energy dispersive X-ray spectroscopy (EDS) on a crystal grain using a transmission electron microscope Indicates.
When a crystal having a cubic crystal structure is represented by a composition formula: (Ti _1-xy Al _x Si _y ) (C _z N _1-z ), periodic concentrations of Ti, Al, and Me in the crystal grains When there is a change (that is, when x, y, and z are not constant values but values that change periodically), the crystal grains are distorted and the hardness is improved. However, the average value of the maximum values 11a, 11b, 11c,... Of the periodically changing x value of the Al content ratio x in the composition formula, which is an index of the change in the concentration of Ti, Al, and Me. the _{X max} also, if the minimum value 12a of periodically value varying x in proportion x of Al, 12b, 12c, an average value of 12d · · · and the _{X min,} the difference of _{X max} and _{X min} When Δx is smaller than 0.03, the above-described crystal grain distortion is small and sufficient hardness cannot be expected. On the other hand, if the difference Δx between X _max and X _min exceeds 0.25, the distortion of the crystal grains becomes too large, lattice defects become large, and the hardness decreases. Therefore, for the change in the concentration of Ti, Al, and Me existing in the crystal grains having a cubic crystal structure, the difference between X _max and X _min was set to 0.03 to 0.25.
Although not particularly essential, a more preferable difference between X _max and X _min is 0.05 to 0.22. Even more preferably, it is 0.08 to 0.15.
Further, in the crystal grains having a cubic crystal structure in which a periodic concentration change of Ti, Al, and Me in the composite nitride or composite carbonitride layer exists, a periodic concentration change of Ti, Al, and Me occurs. When the crystal grains exist along one of the equivalent crystal orientations represented by <001> of the cubic crystal grains, lattice defects due to distortion of the crystal grains hardly occur, and the toughness is improved.
Further, the Ti, Al, and Me concentrations do not substantially change in the plane orthogonal to the orientation in which the periodic concentration changes of Ti, Al, and Me exist, and the Ti Ti in the orthogonal plane is not changed. And the maximum value ΔXo of the change amount of the content ratio x in the total amount of Al and Me is 0.01 or less.
Further, if the period of concentration change along one of the equivalent crystal orientations represented by <001> of the cubic crystal grains is less than 3 nm, the toughness is lowered, and if it exceeds 100 nm, the hardness is improved. Is not fully demonstrated. Therefore, a more desirable period of the concentration change is 3 to 100 nm.
Although not particularly essential, the more preferable period of concentration change is 15 to 80 nm. Even more preferably, it is 25 to 50 nm.

FIG. 6 shows a crystal grain having a cubic crystal structure in which a periodic concentration change of Ti, Al, and Me exists in the cross section of the composite nitride layer or composite carbonitride layer of Ti, Al, and Me of the present invention. FIG. 2 schematically shows that a region A13 and a region B14 exist in the crystal grains.
Regarding the crystal grains in which the region A13 and the region B14 exist in two directions in which the periodic concentration changes of Ti, Al, and Me are orthogonal to each other, there are two directions of strain in the crystal grains. Toughness is improved. Further, since the boundary 15 between the region A and the region B is formed on one of the equivalent crystal planes represented by {110}, misfit between the boundary 15 between the region A and the region B does not occur. High toughness can be maintained.
That is, present along the one of the orientation of the crystal orientation of the equivalent cyclic changes in the concentration of Ti and Al and Me are represented by cubic grains of <001> was the azimuth and azimuth d _A If, azimuth cycle along the _{d a} is 3 ~ 100 nm, a region A13 maximum DerutaXod _a variation of the content x of Al in a plane perpendicular to the direction _{d a} is 0.01 or less, periodic density variation of Ti and Al and Me is present along one of the orientation of the crystal orientation of the equivalent represented by <001> cubic crystal grains perpendicular to the orientation d _a, the orientation If the orientation _{d B,} a period is 3 ~ 100 nm along the direction _{d B,} is 0.01 or less maximum DerutaXod _B of variation of the proportion x of Al in a plane perpendicular to the direction _{d B} When a certain region B14 is formed, strain in two directions exists in the crystal grains. In addition, the toughness is improved, and the boundary 15 between the region A and the region B is formed on one of the equivalent crystal planes represented by {110}, so that the boundary 15 between the region A and the region B is formed. Therefore, high toughness can be maintained.

Lattice constant a of cubic crystal grains in the composite nitride or composite carbonitride layer:
The composite nitride or composite carbonitride layer 2 was subjected to an X-ray diffraction test using an X-ray diffractometer and Cu—Kα rays as a radiation source, and the lattice constant a of cubic crystal grains was determined. cubic grains lattice constant a cubic lattice constant _a TiN of TiN (JCPDS00-038-1420): 4.24173Å and cubic lattice constant _a AlN of AlN (JCPDS00-046-1200): in 4.045Å On the other hand, 0.05a _TiN + 0.95a _AlN ≤a ≤0.4a _TiN + 0.6a When satisfying the relationship of _AlN , it exhibits higher hardness and high thermal conductivity, thereby providing excellent wear resistance. In addition to performance, it has excellent thermal shock resistance.

Area ratio of columnar structure made of individual crystal grains having a cubic structure in composite nitride or composite carbonitride layer 2:
When the area ratio of the columnar structure composed of individual crystal grains having a cubic crystal structure is less than 70% by area, the hardness is undesirably lowered.
Although it is not a particularly essential configuration, the area ratio of the columnar structure composed of individual crystal grains having a preferable cubic structure is 85 area% or more. More preferably, it is 95 area% or more.

Further, the composite nitride or composite carbonitride layer 2 of the present invention has one or two of a Ti carbide layer, nitride layer, carbonitride layer, carbonate layer and carbonitride oxide layer as a lower layer. Even in the case of including a Ti compound layer having a total average layer thickness of 0.1 to 20 μm and / or including an aluminum oxide layer having an average layer thickness of 1 to 25 μm as an upper layer, The combined characteristics of these layers together with the effects of these layers can be further improved by using these known lower layers and upper layers together. When the lower layer includes a Ti compound layer composed of one or more of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer and carbonitride oxide layer, the total of the Ti compound layer When the average layer thickness exceeds 20 μm, the crystal grains are likely to be coarsened and chipping is likely to occur. Further, when an aluminum oxide layer is included as the upper layer, if the total average layer thickness of the aluminum oxide layer exceeds 25 μm, crystal grains are likely to be coarsened and chipping is likely to occur. On the other hand, if the lower layer is less than 0.1 μm, the effect of improving the adhesion with the lower layer of the composite nitride or composite carbonitride layer 2 of the present invention can not be expected, and if the upper layer is less than 1 μm, The effect of improving the wear resistance by forming the upper layer is not remarkable.

The present invention provides a surface-coated cutting tool in which a hard coating layer is provided on the surface of a tool base composed of any of tungsten carbide-based cemented carbide, titanium carbonitride-based cermet, or cubic boron nitride-based ultrahigh-pressure sintered body. The hard coating layer includes at least a composite nitride or composite carbonitride layer 2 of Ti, Al, and Me having an average layer thickness of 1 to 20 μm, and has a composition formula: (Ti _1-xy Al _x Me _y ) ( C _z N _1-z ), the average content ratio X _avg in the total amount of Ti, Al and Me in Al and the average content ratio Y _avg in the total amount of Ti, Al and Me in Me and C The average content ratio Z _avg in the total amount of C and N (where X _avg , Y _avg , and Z _avg are all atomic ratios) is 0.60 ≦ X _avg , 0.005 ≦ Y _avg ≦ 0. 10,0 ≦ Z satisfy _{vg ≦ 0.005,0.605 ≦ X avg + Y} avg ≦ 0.95, complex nitride or composite carbonitride layer 2, composite nitride or composite carbonitride having a face-centered cubic structure of NaCl type The crystal orientation of Ti, Al, and Me composite nitride or composite carbonitride crystal grains containing at least a product phase (cubic crystal phase) and having the cubic structure using an electron beam backscatter diffractometer When analyzed from the longitudinal section direction, the inclination angle formed by the normal line 6 of the {110} plane, which is the crystal plane of the crystal grain, with respect to the normal direction of the tool base surface is measured. When the inclination angle in the range of 0 to 45 degrees is divided into pitches of 0.25 degrees and the frequencies existing in each division are totaled to obtain the inclination angle number distribution, the range of 0 to 12 degrees is obtained. The highest peak exists in the tilt angle section of The frequency total of existing in a range of 12 degrees indicates the proportion of more than 35% of the total power at the inclination angle frequency distribution, crystal grains having a cubic crystal structure, the composition formula: (Ti _{1-x- y} Al _x Me _y ) (C _z N _1-z ) There is a periodic concentration change of Ti, Al, and Me, and the average value of the maximum value of the periodically changing x value of the Al content ratio x the _{X max,} also the average value of the minimum value of the periodically value varying x in proportion x of Al when the _{X min,} the difference Δx from 0.03 to 0.25 _{X max} and _{X min} In a crystal grain having a NaCl type face-centered cubic structure in which a periodic concentration change of Ti, Al, and Me exists, the period along the normal direction of the surface of the tool base is 3 to 100 nm. Has a cubic crystal structure of composite nitride or composite carbonitride Since distortion occurs in the crystal grains, the hardness of the crystal grains is improved, and the toughness is improved while maintaining high wear resistance.
As a result, the effect of improving the chipping resistance is exhibited, the cutting performance is improved over a long period of use as compared with the conventional hard coating layer, and the life of the coated tool is extended.

FIG. 2 is a schematic diagram of a film configuration schematically showing a cross section of a composite nitride or composite carbonitride layer 2 of Ti, Al, and Me constituting the hard coating layer 1 of the present invention. The horizontal stripe pattern indicates a periodic content ratio change of Al in crystal grains in the composite nitride or composite carbonitride layer made of Ti, Al, and Me. 6 is shown when the inclination angle formed by the normal of the {110} plane, which is the crystal plane of the crystal grain, with respect to the normal 5 of the tool base surface (the direction perpendicular to the tool base surface 4 on the cross-section polished surface) is 0 °. It is a schematic diagram. 7 is shown when the inclination angle formed by the normal of the {110} plane, which is the crystal plane of the crystal grain, with respect to the normal 5 of the tool base surface (the direction perpendicular to the tool base surface 4 on the cross-section polished surface) is 45 degrees. It is a schematic diagram. FIG. 3 is a graph showing an example of a tilt angle number distribution obtained for crystal grains having a cubic structure in a cross section of a composite nitride layer or composite carbonitride layer 2 of Ti and Al constituting the hard coating layer 1 of the present invention. . An example of an inclination angle number distribution obtained for a crystal grain having a cubic structure in a cross section of a composite nitride layer or composite carbonitride layer 2 of Ti and Al constituting a hard coating layer according to an embodiment of a comparative example It is a graph to show. In the cross section of the composite nitride layer of Ti, Al, and Me or the composite carbonitride layer 2 constituting the hard coating layer 1 corresponding to one embodiment of the present invention, there is a periodic concentration change of Ti, Al, and Me. One of the equivalent crystal orientations represented by <001> of the cubic crystal grains in which the periodic concentration change of Ti, Al, and Me is expressed for the crystal grains having a cubic crystal structure (indicated by arrows) Is a schematic diagram schematically showing that the change in the Al content ratio x is small in a plane perpendicular to the orientation (displayed from above with a line perpendicular to the arrow). is there. Specifically, the change in the Al content ratio x in the orthogonal plane is 0.01 or less. A bright color portion indicates a region 9 having a relatively high Al content, and a dark color portion indicates a region 10 having a relatively low Al content. In the cross section of the composite nitride layer of Ti, Al, and Me or the composite carbonitride layer 2 constituting the hard coating layer 1 corresponding to one embodiment of the present invention, there is a periodic concentration change of Ti, Al, and Me. The periodicity of Al with respect to the total of Ti, Al, and Me as a result of performing line analysis by energy dispersive X-ray spectroscopy (EDS) using a transmission electron microscope for the crystal grains having a cubic crystal structure An example of the graph of density change x is shown. Specifically, it represents a periodic concentration change of Al in the crystal grains having a cubic structure in the composite nitride or composite carbonitride layer 2. In the graph, three maximum values 11a, 11b and 11 and four minimum values 12a, 12b, 12c and 12d are shown. In the cross section of the composite nitride layer of Ti, Al, and Me or the composite carbonitride layer 2 constituting the hard coating layer 1 corresponding to one embodiment of the present invention, there is a periodic concentration change of Ti, Al, and Me. It is the schematic diagram which represented typically that the area | region A13 and area | region B14 existed in a crystal grain about the crystal grain which has the cubic crystal structure to perform. A boundary 15 between the region A and the region B is formed at a portion where the region A13 and the region B14 are in contact with each other.

The present invention provides a hard tool substrate, that is, a hard surface on the surface of a tool substrate 3 made of any of tungsten carbide-based cemented carbide, titanium carbonitride-based cermet, or cubic boron nitride-based ultrahigh-pressure sintered body. In the surface-coated cutting tool provided with the coating layer 1, the hard coating layer 1 is formed of a composite nitride or composite carbonitride layer 2 of Ti, Al, and Me having an average layer thickness of 1 to 20 μm formed by chemical vapor deposition. Including at least the composition formula: (Ti _1-xy Al _x Me _y ) (C _z N _1-z ), the average content ratios X _avg and Me in the total amount of Ti, Al, and Me in Al The average content ratio Y _avg occupying the total amount of Ti, Al, and Me and the average content ratio Z _avg occupying the total amount of C and N in C (where X _avg , Y _avg , and Z _avg are all atomic ratios) , 0. _{0 ≦ X avg, 0.005 ≦ Y} avg ≦ 0.10,0 satisfy _{≦ Z avg ≦ 0.005,0.605 ≦ X avg} + Y avg ≦ 0.95, complex nitride or composite carbonitride layer 2 includes at least crystal grains having a cubic crystal structure, and the crystal orientation of Ti, Al, and Me composite nitride or composite carbonitride crystal grains having the cubic crystal structure is expressed by an electron beam. When analyzing from the longitudinal section direction using a backscattering diffraction apparatus, the inclination angle formed by the normal line 6 of the {110} plane, which is the crystal plane of the crystal grain, with respect to the normal line direction of the tool base surface is measured. When the inclination angle in the range of 0 to 45 degrees with respect to the normal direction is divided into pitches of 0.25 degrees and the frequencies existing in each division are totaled to obtain the inclination angle number distribution, The highest peak in the tilt angle section within the range of 0-12 degrees And the sum of the frequencies existing within the range of 0 to 12 degrees represents a ratio of 35% or more of the entire frequencies in the tilt angle frequency distribution, and the composition formula is included in the crystal grains having a cubic crystal structure. : (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) there is a periodic concentration change of Ti, Al, and Me, and the content ratio x of x that changes periodically is changed. mean value _{X max} of the maximum value of the value addition, if the average value of the minimum value of the periodically value varying x in proportion x of Al was set to _{X min,} the difference Δx of _{X max} and _{X min} is 0 0.03 to 0.25, and a crystal grain having an NaCl-type face-centered cubic structure in which periodic concentration changes of Ti, Al, and Me exist, the period along the normal direction of the tool base surface is 3 By having a structure of ˜100 nm, chip resistance If the cutting performance is improved, the cutting performance is excellent over a long period of use, and the life of the coated tool is extended, compared to the conventional hard coating layer, the specific implementation Any aspect may be used.
Next, one embodiment of the coated tool of the present invention will be specifically described using examples.

As raw material powders, WC powder, TiC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder and Co powder all having an average particle diameter of 1 to 3 μm are prepared, and these raw material powders are blended as shown in Table 1. Blended into the composition, added with wax, mixed in a ball mill in acetone for 24 hours, dried under reduced pressure, pressed into a compact of a predetermined shape at a pressure of 98 MPa, and the compact was 1370 in a vacuum of 5 Pa. Vacuum sintered under the condition of holding for 1 hour at a predetermined temperature in the range of ~ 1470 ° C, and after sintering, manufacture tool bodies A to C made of WC-base cemented carbide with ISO standard SEEN1203AFSN insert shape, respectively. did.

In addition, as raw material powders, TiCN (mass ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, WC powder, Co powder, all having an average particle diameter of 0.5 to 2 μm. And Ni powder are prepared, these raw material powders are blended in the blending composition shown in Table 2, wet mixed by a ball mill for 24 hours, dried, and then pressed into a compact at a pressure of 98 MPa. The body was sintered in a nitrogen atmosphere of 1.3 kPa at a temperature of 1500 ° C. for 1 hour, and after sintering, a tool base D made of TiCN-based cermet having an ISO standard SEEN1203AFSN insert shape was produced.

Next, a chemical vapor deposition apparatus is used on the surfaces of these tool bases A to D,
(A) Formation conditions shown in Table 4, that is, a gas group A composed of NH ₃ and H ₂ , TiCl ₄ , Al (CH ₃ ) ₃ , AlCl ₃ , MeCl _n (where SiCl ₄ , ZrCl ₄ , BCl ₃ , VCl ₄ , CrCl ₂ ), NH ₃ , N ₂ , H ₂ gas group B, and a method of supplying each gas, the reaction gas composition (gas group A and gas group B was combined) % As a gas group A, NH ₃ : 3.5 to 4.0%, H ₂ : 65 to 75%, as a gas group B, AlCl ₃ : 0.6 to 0.9%, TiCl ₄ : 0.2 to 0.3%, Al (CH ₃ ) ₃ : 0 to 0.5%, MeCl _n (however, any one of SiCl ₄ , ZrCl ₄ , BCl ₃ , VCl ₄ , CrCl ₂ ): 0 _{.1 ~ 0.2%, N 2:} 0 0 ~ 12.0%, _{H 2:} remainder, reaction atmosphere pressure: 4.5 ~ 5.0 kPa, Temperature of reaction atmosphere: 700 ~ 900 ° C., the supply cycle 1 to 5 seconds, the gas supply time per cycle 0.15 A thermal CVD method is performed for a predetermined time with a phase difference between gas supply A and gas supply B of 0.25 to 0.25 seconds and a target layer thickness shown in Table 7 (Ti _{1-x -y} Al _x Me _{y) (the} present invention coated tool 1-15 were prepared by forming a hard coating layer 1 consisting of C _{z N 1-z)} layer.
For the coated tools 6 to 13 of the present invention, either the lower layer or the upper layer shown in Table 6 was formed under the formation conditions shown in Table 3.

For comparison purposes, Ti, Al, and Me composite nitride or composite carbonitride are formed on the surfaces of the tool bases A to D under the conditions shown in Table 5 and the target layer thickness (μm) shown in Table 8. The hard coating layer 1 including the layer 2 was formed by vapor deposition. At this time, the hard coating layer 1 is formed so that the reaction gas composition on the surface of the tool base does not change with time during the film formation process of the (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer. Comparative coated tools 1 to 15 were produced by forming.
As with the coated tools 6 to 13 of the present invention, for the comparative coated tools 6 to 13, either the lower layer or the upper layer shown in Table 6 was formed under the formation conditions shown in Table 3.

The Ti, Al, and Me composite nitride or composite carbonitride layer 2 constituting the hard coating layer 1 of the present invention coated tools 1 to 15 and comparative coated tools 1 to 15 are perpendicular to the tool substrate surface 4 With the cross section of the hard coating layer 1 as a polished surface, it is set in a lens barrel of a field emission scanning electron microscope, and an electron beam with an acceleration voltage of 15 kV is applied to the polished surface at an incident angle of 70 degrees with an irradiation current of 1 nA. Then, each crystal grain having a cubic crystal lattice existing within the measurement range of the cross-section polished surface is irradiated, and using an electron backscatter diffraction image apparatus, the tool base surface 4 and a length of 100 μm in the horizontal direction are used. With respect to the hard coating layer 1 within a measurement range of a distance equal to or less than the film thickness along a cross section in a direction perpendicular to the surface 4, the normal 5 of the substrate surface (the substrate surface 4 on the cross-section polished surface) at an interval of 0.01 μm / step. Direction) The inclination angle formed by the normal line 6 of the {110} plane which is the crystal plane of the crystal grain is measured, and based on the measurement result, the measurement inclination angle within the range of 0 to 45 degrees out of the measurement inclination angles Is divided into pitches of 0.25 degrees, and by counting the frequencies present in each section, the presence of a frequency peak within the range of 0 to 12 degrees is confirmed, and 0 to 12 degrees The ratio of the frequency existing in the range of was determined.

The Ti, Al, and Me composite nitride or composite carbonitride layer 2 constituting the hard coating layer 1 of the present invention coated tools 1 to 15 and comparative coated tools 1 to 15 was scanned with an electron microscope (magnification 5000). Multiple times and 20000 times).
With respect to the coated tools 1 to 15 of the present invention, a columnar structure (Ti _1-xy) containing a cubic crystal or a mixed phase of a cubic crystal and a hexagonal crystal as shown in the schematic diagram of the film structure shown in FIG. An Al _x Me _y ) (C _z N _1-z ) layer was confirmed. In addition, the periodic distribution of Ti, Al, and Me (concentration change, content ratio change) exists in the cubic crystal grains, and energy dispersive X-ray spectroscopy (using a transmission electron microscope) It was confirmed by surface analysis by EDS).
Further, for the coated tools 1 to 15 of the present invention and the comparative coated tools 1 to 15, cubic results existing in the composite nitride or composite carbonitride layer 2 using the results of surface analysis by EDS using a transmission electron microscope. The average value of the maximum value of x in the x period corresponding to five cycles of the crystal grains is defined as X _max, and the average value of the minimum value of x in the same period of five cycles is defined as X _min , and the difference Δx (= X _max -X _min ) was determined.
Regarding the coated tools 1 to 15 of the present invention, the value Δx was confirmed to be 0.03 to 0.25.

In addition, the cross-sections of the constituent layers of the inventive coated tools 1 to 15 and comparative coated tools 1 to 15 in the direction perpendicular to the tool substrate were measured using a scanning electron microscope (with a magnification of 5000 times). When the average layer thickness was obtained by measuring and averaging the five layer thicknesses, the average layer thickness was substantially the same as the target layer thickness shown in Tables 7 and 8.

The average Al content and the average Me content of the composite nitride or composite carbonitride layer 2 of the coated tools 1 to 15 of the present invention and the comparative coated tools 1 to 15 were measured using an electron beam microanalyzer (EPMA, Electron-Probe). -In a sample whose surface was polished using Micro-Analyzer), an electron beam was irradiated from the sample surface side, and the average Al content ratio X _avg and Me of Al was obtained from an average of 10 points of the analysis result of the characteristic X-ray obtained. The average content ratio Y _avg was determined.
The average C content ratio Z _avg was determined by secondary ion mass spectrometry (SIMS, Secondary-Ion-Mass-Spectroscopy). The ion beam was irradiated in the range of 70 μm × 70 μm from the sample surface side, and the concentration in the depth direction was measured for the components emitted by the sputtering action. The average C content ratio Z _avg indicates an average value in the depth direction of the composite nitride or composite carbonitride layer 2 of Ti, Al, and Me. However, the content ratio of C excludes the inevitable content ratio of C that is included without intentionally using a gas containing C as a gas raw material. Specifically, the content ratio (atomic ratio) of the C component contained in the composite nitride or the composite carbonitride layer 2 when the supply amount of Al (CH ₃ ) ₃ is set to 0 is the inevitable C content ratio. The unavoidable C content is determined from the content (atomic ratio) of the C component contained in the composite nitride or composite carbonitride layer 2 obtained when Al (CH ₃ ) ₃ is intentionally supplied. The subtracted value was determined as Z _avg .

Further, with respect to the coated tools 1 to 15 of the present invention and the comparative coated tools 1 to 15, the tool substrate surface 4 and the tool substrate surface 4 are horizontally aligned using a scanning electron microscope (magnification 5000 times and 20000 times) from the cross-sectional direction perpendicular to the tool substrate. Individual crystal grains in the (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer constituting the composite nitride or composite carbonitride layer 2 existing in the range of a length of 10 μm in the direction The particle width w in the direction parallel to the substrate surface 4 and the particle length l in the direction perpendicular to the substrate surface 4 are measured, and the aspect ratio of each crystal grain is observed. a (= l / w) is calculated, the average value of the aspect ratio a obtained for each crystal grain is calculated as the average aspect ratio A, and the average value of the grain width w obtained for each crystal grain is Calculated as average particle width W It was.

Further, by using an electron beam backscatter diffractometer, a cross section in a direction perpendicular to the tool base surface 4 of the hard coating layer 1 composed of a composite nitride or composite carbonitride layer 2 of Ti, Al, and Me was used as a polished surface. In the state, it is set in a lens barrel of a field emission scanning electron microscope, and an electron beam with an acceleration voltage of 15 kV at an incident angle of 70 degrees is applied to the polished surface within the measurement range of the sectional polished surface with an irradiation current of 1 nA. 0.01 μm / step is applied to the entire hard coating layer composed of a composite nitride or composite carbonitride layer 2 of Ti, Al, and Me over a length of 100 μm in the horizontal direction with respect to the tool base surface 4. Measure the electron backscatter diffraction image at intervals of, identify the cubic crystal structure or hexagonal crystal structure by analyzing the crystal structure of each crystal grain, and composite nitriding of Ti, Al and Me Or composite carbonitriding The physical layer 2 was confirmed to contain a cubic composite nitride or composite carbonitride phase, and the area ratio of the cubic crystal phase contained in the layer was determined.

Further, a micro region of the composite nitride or composite carbonitride layer 2 was observed using a transmission electron microscope, and surface analysis was performed from the cross-sectional side using energy dispersive X-ray spectroscopy (EDS). However, in the crystal grains having the cubic crystal structure, the periodic concentration change of Ti, Al, and Me in the composition formula: (Ti _1-xy Al _x Si _y ) (C _z N _1-z ) The presence or absence was confirmed. When this concentration change exists, the equivalent crystal orientation represented by <001> of the cubic crystal grain is obtained by performing electron beam diffraction on the crystal grain, so that the periodic concentration change of Ti, Al, and Me is represented by <001> of the cubic crystal grain. It is confirmed that it exists along one azimuth direction, and line analysis by EDS along that azimuth is performed in a section for five periods, and the periodic concentration change of Al with respect to the total of Ti, Al, and Me is confirmed. The average value of the local maximum values is obtained as X _max , and the average value of the local minimum values of the periodic concentration change of Al with respect to the sum of Ti, Al and Me in the same section is obtained as X _min , and the difference Δx (= to determine the X _max -X _min).

Further, line analysis along a direction orthogonal to one of the equivalent crystal orientations represented by <001> of cubic crystal grains having periodic concentration changes of Ti, Al, and Me is performed in the five cycles. The difference between the maximum value and the minimum value of the Al content ratio x in the interval corresponding to the minute distance is calculated as <001> for the cubic crystal grains having a periodic concentration change of Ti, Al, and Me. The maximum change amount ΔXo in the plane perpendicular to one of the equivalent crystal orientations represented by

Further, for the crystal grains in which the region A13 and the region B14 are present in the crystal grains, the periodicity corresponding to five periods of Al with respect to the total of Ti, Al, and Me is similarly provided for each of the regions A13 and B14. The maximum value Δx (= X _max −X _min ) of the difference between the maximum value X _max and the minimum value X _min of the minimum value of the concentration change is obtained, and the periodicity of Ti, Al, and Me is determined. Maximum value and minimum value of Al content ratio x with respect to the total of Ti, Al, and Me in a plane orthogonal to one of the equivalent crystal orientations represented by <001> of cubic crystal grains having a concentration change The difference in values was determined as the maximum amount of change.
That is, a periodic concentration change of Ti, Al, and Me in the region A13 exists along one of the equivalent crystal orientations represented by <001> of the cubic crystal grains, and the orientation is defined as the orientation d. If the _a, along with determining the period of the concentration variation along the direction d _a, perform line analysis along a direction perpendicular to the direction d _a in a section corresponding to the distance of the five cycles, Al in the section The difference between the maximum value and the minimum value of the content ratio x of one of the equivalent crystal orientations represented by <001> of cubic crystal grains having a periodic concentration change of Ti, Al, and Me The maximum value ΔXod _A of the amount of change in the orthogonal plane was obtained.
Further, a periodic concentration change of Ti, Al, and Me in the region B14 exists along one of the equivalent crystal orientations represented by <001> of the cubic crystal grains, and the orientation is defined as the orientation d. _In the case of _B , the period of concentration change along the direction d _B is obtained, and the line analysis along the direction orthogonal to the direction d _B is performed in the section corresponding to the distance of the five periods, and the Al in that section is obtained. The difference between the maximum value and the minimum value of the content ratio x of one of the equivalent crystal orientations represented by <001> of cubic crystal grains having a periodic concentration change of Ti, Al, and Me The maximum value ΔXod _B of the amount of change within the orthogonal plane was obtained.
In the coated tools 1 to 15 of the present invention, d _A and d _B are orthogonal to each other, and the boundary 15 between the region A and the region B is formed on one of the equivalent crystal planes represented by {110}. I was sure that.
Such a period was confirmed with at least one crystal grain in the field of observation of a minute region of the composite nitride or composite carbonitride layer 2 using a transmission electron microscope. Regarding the crystal grains in which the region A13 and the region B14 exist in the crystal grains, at least one of the crystals in the field of observation of the minute region of the composite nitride or composite carbonitride layer 2 using a transmission electron microscope is used. It calculated | required by calculating the average of the value evaluated by each of this area | region A13 and area | region B14 of a grain.
Tables 7 and 8 show the various measurement results described above.

Next, the coated tools 1 to 15 of the present invention and the comparative coated tools 1 to 15 in the state where each of the various coated tools is clamped by a fixing jig at the tip of a tool steel cutter having a cutter diameter of 125 mm is described below. The dry high-speed face milling, which is a kind of high-speed interrupted cutting of alloy steel, and a center-cut cutting test were performed, and the flank wear width of the cutting blade was measured.

Tool substrate: Tungsten carbide-based cemented carbide, titanium carbonitride-based cermet,
Cutting test: Dry high-speed face milling, center cutting,
Work material: JIS / SCM440 block material with a width of 100 mm and a length of 400 mm,
Rotational speed: 980 min ⁻¹
Cutting speed: 385 m / min,
Cutting depth: 1.2 mm,
Single blade feed amount: 0.12 mm / tooth,
Cutting time: 8 minutes,
Table 9 shows the cutting test results.

As raw material powders, WC powder, TiC powder, ZrC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder and Co powder each having an average particle diameter of 1 to 3 μm are prepared. Compounded in the formulation shown in Table 10, added with wax, ball mill mixed in acetone for 24 hours, dried under reduced pressure, press-molded into a green compact of a predetermined shape at a pressure of 98 MPa. In a 5 Pa vacuum, vacuum sintering is performed at a predetermined temperature within a range of 1370 to 1470 ° C. for 1 hour, and after sintering, the cutting edge is subjected to a honing process of R: 0.07 mm. Tool bases α to γ made of WC-base cemented carbide having the insert shape of CNMG120212 were manufactured.

In addition, as raw material powders, TiCN (TiC / TiN = 50/50 by mass ratio) powder, NbC powder, WC powder, Co powder, and Ni powder each having an average particle diameter of 0.5 to 2 μm are prepared, These raw material powders were blended into the composition shown in Table 11, wet mixed with a ball mill for 24 hours, dried, and then pressed into a green compact at a pressure of 98 MPa. Sintered in an atmosphere at a temperature of 1500 ° C. for 1 hour, and after sintering, the cutting edge part is subjected to a honing process of R: 0.09 mm so that the TiCN base has an insert shape of ISO standard / CNMG120212 A cermet tool substrate δ was formed.

Next, using the chemical vapor deposition apparatus on the surfaces of the tool bases α to γ and the tool base δ, a thermal CVD method is performed for a predetermined time under the formation conditions shown in Table 4 in the same manner as in Example 1. Thus, the coated tools 16 to 30 of the present invention were manufactured by forming the (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer shown in Table 13.
For the coated tools 19 to 28 of the present invention, the lower layer and the upper layer shown in Table 12 were formed under the formation conditions shown in Table 3.

For comparison purposes, a chemical vapor deposition apparatus is used on the surfaces of the tool bases α to γ and the tool base δ, and the conditions shown in Table 5 and the target layer thickness shown in Table 14 are the same as those of the coated tool of the present invention. Comparative coating tools 16 to 30 shown in Table 14 were manufactured by vapor-depositing a hard coating layer.
Similar to the coated tools 19 to 28 of the present invention, the comparative coated tools 19 to 28 were formed with the lower layer and the upper layer shown in Table 12 under the forming conditions shown in Table 3.

In addition, the cross-section of each component layer of the inventive coated tool 16 to 30 and the comparative coated tool 16 to 30 is measured using a scanning electron microscope (5000 times magnification), and the layer thickness at five points in the observation field is measured. When the average layer thickness was obtained on average, both showed the same average layer thickness as the target layer thicknesses shown in Tables 13 and 14.
For the hard coating layers of the inventive coated tools 16 to 30 and comparative coated tools 16 to 30, the average Al content ratio X _avg and the average Me content ratio Y were obtained using the same method as that shown in Example 1. _avg , average C content ratio Z _avg , inclination angle number distribution, periodic concentration change difference Δx (= X _max -X _min ) and period, lattice constant a, average grain width W of crystal grains, average aspect ratio A, crystal The area ratio of the cubic crystal phase in the grains was determined.
Tables 13 and 14 show the results.

Next, the present coated tools 16 to 30 and the comparative coated tools 16 to 30 are shown below with all of the various coated tools screwed to the tip of the tool steel tool with a fixing jig. A dry high-speed intermittent cutting test of alloy steel and a wet high-speed intermittent cutting test of cast iron were carried out, and both measured the flank wear width of the cutting edge.
Cutting condition 1:
Work material: JIS · S45C lengthwise equal 4 round grooved round bars,
Cutting speed: 380 m / min,
Cutting depth: 1.5 mm,
Feed: 0.15 mm / rev,
Cutting time: 5 minutes,
(Normal cutting speed is 220 m / min),
Cutting condition 2:
Work material: JIS / FCD700 lengthwise equal length 4 round bar with round groove,
Cutting speed: 330 m / min,
Cutting depth: 1.0 mm,
Feed: 0.1 mm / rev,
Cutting time: 5 minutes,
(Normal cutting speed is 200 m / min),
Table 15 shows the results of the cutting test.

As the raw material powder, cBN powder, TiN powder, TiCN powder, TiC powder, Al powder, and Al ₂ O ₃ powder each having an average particle diameter in the range of 0.5 to 4 μm were prepared. The mixture is blended in the composition shown in FIG. 1, wet mixed with a ball mill for 80 hours, dried, and then pressed into a green compact having a diameter of 50 mm × thickness: 1.5 mm under a pressure of 120 MPa. The green compact is sintered in a vacuum atmosphere at a pressure of 1 Pa at a predetermined temperature in the range of 900 to 1300 ° C. for 60 minutes to obtain a presintered body for a cutting edge piece. In addition, Co: 8% by mass, WC: remaining composition, and diameter: 50 mm × thickness: 2 mm, superposed on a WC-based cemented carbide support piece with a normal super-high pressure Insert into the sintering machine, normal conditions A certain pressure: 4 GPa, temperature: a predetermined temperature within the range of 1200 to 1400 ° C., holding at a high pressure under a condition of holding time: 0.8 hour, and after sintering, the upper and lower surfaces are polished with a diamond grindstone, and wire discharge It is divided into predetermined dimensions by a processing apparatus, and further Co: 5 mass%, TaC: 5 mass%, WC: remaining composition and shape of JIS standard CNGA12041 (thickness: 4.76 mm × inscribed circle diameter: 12. The brazing part (corner part) of the WC-based cemented carbide insert body having a 7 mm 80 ° rhombus) has a composition consisting of Zr: 37.5%, Cu: 25%, Ti: the rest in mass%. After brazing using a brazing material of Ti-Zr-Cu alloy having a predetermined dimension, the cutting edge portion is subjected to honing with a width of 0.13 mm and an angle of 25 °, and further subjected to finish polishing. ISO regulations Tool substrate 2A having the insert shape of CNGA120412, 2B were prepared, respectively.

Next, (Ti _1-xy Al _x Me _y ) (C) is used on the surfaces of these tool bases 2A and 2B under the conditions shown in Table 4 by the same method as in Example 1 using a chemical vapor deposition apparatus. _The coated tools 31 to 40 of the present invention shown in Table 18 were manufactured by vapor-depositing a hard coating layer including a _z N _1-z ) layer with a target layer thickness.
For the inventive coated tools 34 to 39, the lower layer and the upper layer shown in Table 17 were formed under the formation conditions shown in Table 3.

Further, for the purpose of comparison, a chemical vapor deposition apparatus was used on the surfaces of the tool bases 2A and 2B, and (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) under the conditions shown in Table 5. The comparative coating tools 31 to 40 shown in Table 19 were manufactured by vapor-depositing a hard coating layer including a layer) with a target layer thickness.
As with the inventive coated tools 34 to 39, for the comparative coated tools 34 to 39, the lower layer and the upper layer shown in Table 17 were formed under the formation conditions shown in Table 3.

In addition, the cross-sections of the constituent layers of the inventive coated tools 31 to 40 and comparative coated tools 31 to 40 were measured using a scanning electron microscope (5000 times magnification) to measure the layer thickness at five points in the observation field. As a result, the average layer thickness was obtained by averaging, and both showed an average layer thickness substantially the same as the target layer thickness shown in Tables 18 and 19.

For the hard coating layers of the inventive coated tools 31 to 40 and comparative coated tools 31 to 40, using the same method as that shown in Example 1, the average layer thickness, the average Al content ratio X _avg , the average Me content ratio Y _avg , average C content ratio Z _avg , inclination angle number distribution, periodic concentration change difference Δx (= X _max −X _min ) and period, lattice constant a, average grain width W of crystal grains, average aspect The ratio A and the area ratio of the cubic crystal phase in the crystal grains were determined.
Tables 18 and 19 show the results.

Next, carburizing as shown below for the coated tools 31 to 40 of the present invention and the comparative coated tools 31 to 40 in a state where all the various coated tools are screwed to the tip of the tool steel tool with a fixing jig. A dry high-speed intermittent cutting test was performed on the quenched alloy steel, and the flank wear width of the cutting edge was measured.
Cutting test: Dry high-speed intermittent cutting of carburized and quenched alloy steel,
Work material: JIS · SCr420 (Hardness: HRC62) lengthwise equidistant four round grooved round bars,
Cutting speed: 250 m / min,
Incision: 0.12 mm,
Feed: 0.12 mm / rev,
Cutting time: 4 minutes,
Table 20 shows the results of the cutting test.

As in Example 1, WC powder, TiC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder and Co powder each having an average particle diameter of 1 to 3 μm were prepared as raw material powders. Then, blended into the composition shown in Table 1, added with wax, ball mill mixed in acetone for 24 hours, dried under reduced pressure, and then press-molded into a green compact of a predetermined shape at a pressure of 98 MPa. WC based cemented carbide tool with ISO standard SEEN1203AFSN insert shape after vacuum sintering in 5 Pa vacuum at a predetermined temperature in the range of 1370-1470 ° C. for 1 hour. Substrates A to C were produced respectively.

Next, by using a chemical vapor deposition apparatus on the surfaces of these tool bases A to C, a thermal CVD method is performed for a predetermined time under the formation conditions shown in Table 4 in the same manner as in Example 1, so that Table 23 The coated tools 41 to 55 of the present invention were manufactured by forming the (Ti _1-xy Al _x Me _y ) (C _z N _1-z ) layer shown in FIG.
For the inventive coated tools 45 to 52, the lower layer and the upper layer shown in Table 22 were formed under the formation conditions shown in Table 3.

For comparison purposes, a hard coating layer is similarly applied to the surfaces of the tool bases A to C in the same manner as in the coated tool of the present invention using the chemical vapor deposition apparatus and the conditions shown in Table 21 and the target layer thickness shown in Table 24. Comparative coating tools 41 to 55 shown in Table 24 were manufactured by vapor deposition.
As with the coated tools 45 to 52 of the present invention, the lower and upper layers shown in Table 22 were formed for the comparative coated tools 45 to 52 under the forming conditions shown in Table 3.

Further, the cross-sections of the constituent layers of the inventive coated tools 41 to 55 and the comparative coated tools 41 to 55 are measured using a scanning electron microscope (5000 times magnification), and the layer thicknesses at five points in the observation field are measured. When the average layer thickness was obtained on average, both showed the same average layer thickness as the target layer thicknesses shown in Tables 23 and 24.
Further, with respect to the hard coating layers of the inventive coated tools 41 to 55 and the comparative coated tools 41 to 55, the average Al content ratio X _avg and the average Me content ratio Y are obtained using the same method as that shown in Example 1. _avg , average C content ratio Z _avg , inclination angle number distribution, periodic concentration change difference Δx (= X _max -X _min ) and period, lattice constant a, average grain width W of crystal grains, average aspect ratio A, crystal The area ratio of the cubic crystal phase in the grains was determined.
Tables 23 and 24 show the results.

Next, with respect to the inventive coated tools 41 to 55 and the comparative coated tools 41 to 55, the various coated tools are clamped on a tool steel cutter tip having a cutter diameter of 125 mm by a fixing jig. A wet high-speed face milling, which is a kind of high-speed intermittent cutting of carbon steel, and a center-cut cutting test were performed, and the flank wear width of the cutting edge was measured.

Tool base: Tungsten carbide-based cemented carbide cutting test: wet high-speed face milling, center cut machining,
Work material: Block material of JIS / S55C width 100mm, length 400mm,
Rotational speed: 980 min ⁻¹
Cutting speed: 385 m / min,
Cutting depth: 1.2 mm,
Single blade feed: 0.12 mm / tooth,
Cutting oil: Yes Cutting time: 5 minutes
Table 25 shows the cutting test results.

From the results shown in Table 9, Table 15, Table 20 and Table 25, the coated tool of the present invention is a hard coating layer containing at least cubic crystal grains of a composite nitride or composite carbonitride of Ti, Al and Me. The cubic crystal grains exhibit {110} plane orientation and have a columnar structure, and the presence of changes in the concentration of Ti, Al, and Me in the crystal grains causes hardness due to distortion of the crystal grains. Improves toughness while maintaining high wear resistance. Moreover, even when used for high-speed intermittent cutting where intermittent and impactful high loads act on the cutting edge, it has excellent chipping resistance and chipping resistance, resulting in excellent wear resistance over a long period of use. It is clear that it will work.

On the other hand, in the hard coating layer containing at least cubic crystal grains of the composite nitride or composite carbonitride of Ti, Al and Me constituting the hard coating layer, since it does not have the requirements specified in the present invention, When used for high-speed intermittent cutting with high heat generation and intermittent / impact high loads acting on the cutting edge, it is apparent that the life is shortened in a short time due to occurrence of chipping, chipping and the like.

As described above, the coated tool of the present invention can be used not only for high-speed intermittent cutting of alloy steel but also as a coated tool for various work materials, and has excellent chipping resistance over a long period of use. Since it exhibits wear resistance, it can sufficiently satisfy the high performance of the cutting device, the labor saving and energy saving of the cutting work, and the cost reduction.

DESCRIPTION OF SYMBOLS 1 Hard coating layer 2 The composite nitride or composite carbonitride layer which consists of Ti, Al, and Me 3 Tool base | substrate 4 Base | substrate surface 5 Normal of the base | substrate surface 6 Normal whose inclination angle of {110} plane is 0 degree 7 {110 } Normal with 45 ° tilt angle 8 Crystalline plane with {110} tilt angle 45 ° 9 Region with relatively high Al content 10 Region with relatively low Al content 11a Maximum value 1
11b Maximum value 2
11c maximum 3
12a Minimum 1
12b Minimum value 2
12c local minimum 3
12d local minimum 4
13 Area A
14 Area B
15 Boundary between regions A and B

Claims (9)

1. In a surface-coated cutting tool in which a hard coating layer is formed on the surface of a tool base composed of any of tungsten carbide-based cemented carbide, titanium carbonitride-based cermet, or cubic boron nitride-based ultrahigh pressure sintered body,
   (A) The hard coating layer is a composite nitride of Ti, Al, and Me (where Me is a kind of element selected from Si, Zr, B, V, and Cr) having an average layer thickness of 1 to 20 μm or When at least the composite carbonitride layer is included and expressed by the composition formula: (Ti _1-xy Al _x Me _y ) (C _z N _1-z ), the Ti of the composite nitride or the composite carbonitride layer The average content ratio X _avg in the total amount of Al and Me and Me, the average content ratio Y _avg in the total amount of Ti, Al and Me in Me and the average content ratio Z _avg in the total amount of C and N in C , X _avg , Y _avg , and Z _avg are all atomic ratios) are 0.60 ≦ X _avg , 0.005 ≦ Y _avg ≦ 0.10, 0 ≦ Z _avg ≦ 0.005, 0.605 ≦ X _avg + Y _avg ≦ 0.95 is satisfied,
   (B) The composite nitride or composite carbonitride layer includes at least a composite nitride or composite carbonitride phase of Ti, Al, and Me having a NaCl type face-centered cubic structure,
   (C) Electron beam backscattering of crystal orientation of Ti, Al, and Me composite nitride or composite carbonitride crystal grains having NaCl-type face-centered cubic structure in the composite nitride or composite carbonitride layer When analyzing from the longitudinal section direction using a diffractometer, the inclination angle formed by the normal of the {110} plane, which is the crystal plane of the crystal grain, with respect to the normal direction of the tool base surface is measured, When the inclination angle in the range of 0 to 45 degrees with respect to the line direction is divided into pitches of 0.25 degrees and the frequencies existing in each division are totaled to obtain the inclination angle number distribution, 0 to 12 The highest peak exists in the inclination angle section within the range of degrees, and the total of the frequencies existing in the range of 0 to 12 degrees indicates a ratio of 35% or more of the entire degrees in the inclination angle frequency distribution,
   (D) Further, in the crystal grains of the composite nitride or composite carbonitride of Ti, Al, and Me having the NaCl type face-centered cubic structure, the composition formula: (Ti _1-xy Al _x Me _y ) There is a periodic concentration change of Ti, Al, and Me in (C _z N _1-z ), and the average value of the maximum value of the periodically changing x value of the Al content ratio x is expressed as X _max , If the average value of the minimum value of the periodically value varying x in proportion x of Al was set to _{X min,} the difference Δx of _{X max} and _{X min} is 0.03-0.25,
   (E) In a crystal grain having a NaCl-type face-centered cubic structure in which a periodic concentration change of Ti, Al, and Me in the composite nitride or composite carbonitride layer exists, the normal direction of the tool base surface A surface-coated cutting tool, wherein the period along the axis is 3 to 100 nm.
2. Periodic concentration change of Ti, Al, and Me in a crystal grain having a NaCl type face-centered cubic structure in which a periodic concentration change of Ti, Al, and Me exists in the composite nitride or composite carbonitride layer Is present along one of the equivalent crystal orientations represented by <001> of the cubic crystal grains, and the period along the orientation is 3 to 100 nm, and in a plane perpendicular to the orientation. 2. The surface-coated cutting tool according to claim 1, wherein the maximum value ΔXo of the amount of change in the Al content ratio x is 0.01 or less.
3. In a crystal grain having a NaCl-type face-centered cubic structure in which a periodic concentration change of Ti, Al, and Me in the composite nitride or composite carbonitride layer exists,
   (A) A periodic concentration change of Ti, Al, and Me exists along one of the equivalent crystal orientations represented by <001> of the cubic crystal grains, and the orientation is defined as an orientation d _A Then, the azimuth _d cycle along the _a is 3 ~ 30 nm, orientation _d maximum value of the variation in the content ratio x of Al in a plane perpendicular to the _a DerutaXod _a region a is 0.01 or less,
   Periodic density variation of (b) Ti, Al and Me is present along one of the orientation of the crystal orientation of the equivalent represented by <001> cubic crystal grains perpendicular to the orientation d _A, When the azimuth and azimuth _{d B,} a period is 3 ~ 30 nm along the direction _{d B,} the maximum value DerutaXod _B of variation of the proportion x of Al in a plane perpendicular to the direction _{d B} 0.01 Region B, which is
   The region A and the region B exist in a crystal grain, and a boundary between the region A and the region B is formed on one of the equivalent crystal planes represented by {110}. Item 4. The surface-coated cutting tool according to Item 1.
4. With respect to the composite nitride or composite carbonitride layer, the lattice constant a of the crystal grains having the NaCl type face centered cubic structure is obtained from X-ray diffraction, and the lattice constant a of the crystal grains having the NaCl type face centered cubic structure is obtained. but the feature that the relative cubic TiN lattice constant _{a TiN} and cubic AlN lattice constant _{a AlN,} satisfying the relationship _{0.05a TiN + 0.95a AlN ≦ a ≦} 0.4a TiN + 0.6a AlN The surface-coated cutting tool according to any one of claims 1 to 3.
5. When the composite nitride or the composite carbonitride layer is observed from the longitudinal cross-sectional direction of the layer, the composite nitride or composite carbonitride of Ti, Al, and Me having a NaCl-type face-centered cubic structure in the layer 5. The columnar structure according to claim 1, wherein the average grain width W of the crystal grains of the product is 0.1 to 2.0 μm and the average aspect ratio A is 2 to 10. Surface coated cutting tool.
6. The composite nitride or the composite carbonitride layer is characterized in that an area ratio of Ti, Al, and Me composite nitride or composite carbonitride having a NaCl type face-centered cubic structure is 70% by area or more. The surface-coated cutting tool according to any one of claims 1 to 4.
7. Tool base composed of any one of the tungsten carbide-based cemented carbide, titanium carbonitride-based cermet, or cubic boron nitride-based ultrahigh pressure sintered body, and the composite nitride or composite carbonitride layer of Ti, Al, and Me Between the Ti carbide layer, nitride layer, carbonitride layer, carbonate layer and carbonitride layer, and a total average layer of 0.1 to 20 μm The surface-coated cutting tool according to any one of claims 1 to 6, wherein a lower layer including a Ti compound layer having a thickness exists.
8. 8. The upper layer including at least an aluminum oxide layer is present on the composite nitride or composite carbonitride layer at a total average layer thickness of 1 to 25 μm. Surface coated cutting tool.
9. 9. The composite nitride or composite carbonitride layer is formed by a chemical vapor deposition method containing at least trimethylaluminum as a reactive gas component. A method of manufacturing a surface-coated cutting tool.

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