WO2017073790A1

WO2017073790A1 - Surface-coated cutting tool, and production method therefor

Info

Publication number: WO2017073790A1
Application number: PCT/JP2016/082354
Authority: WO
Inventors: 翔龍岡; 佐藤　賢一; 光亮柳澤; 西田　真
Original assignee: 三菱マテリアル株式会社
Priority date: 2015-10-30
Filing date: 2016-10-31
Publication date: 2017-05-04

Abstract

In this surface-coated cutting tool, a hard coating layer (2) includes at least a layer (3) of a composite nitride or composite carbonitride (compositional formula: (Ti_1-xAl_x)(C_yN_1-y)) of Ti and Al formed by chemical vapour deposition, a layer (3) of a composite nitride or composite carbonitride (compositional formula: (Ti_1-α-βAl_αMe_β)(C_γN_1-γ)) of Ti, Al, and Me, or a layer (3) of a composite nitride or composite carbonitride (compositional formula: (Cr_1-pAl_p)(C_qN_1-q)) of Cr and Al. Crystal grains which form the layer (3) of the composite nitride or composite carbonitride include crystal grains which have a cubic crystal structure. The crystal grains having the cubic crystal structure have a prescribed average crystal grain orientation spread and inclination angle frequency distribution.

Description

Surface-coated cutting tool and manufacturing method thereof

The present invention has high heat generation such as carbon steel, alloy steel, cast iron, etc., and has high wear resistance and chipping resistance with a high hard coating layer in high-speed intermittent cutting processing in which an impact load is applied to the cutting edge. It is related with the surface coating cutting tool (henceforth a coating tool) which exhibits the cutting performance which was excellent over long-term use.
The present application is filed on October 30, 2015, Japanese Patent Application No. 2015-214519 filed in Japan, October 30, 2015, Japanese Patent Application No. 2015-214523 filed in Japan, October 30, 2015 The priority is claimed based on Japanese Patent Application No. 2015-214526 filed in Japan and Japanese Patent Application No. 2016-2111415 filed in Japan on October 28, 2016, the contents of which are incorporated herein by reference.

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 There is known a coated tool in which a Ti—Al-based composite nitride layer is formed by physical vapor deposition on the surface of a tool base (hereinafter collectively referred to as a tool base) as a hard coating layer, These are known to exhibit 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, Patent Document 1 discloses a surface-coated cutting tool in which a hard coating layer is formed on the surface of a tool base, and the hard coating layer is configured by one or a plurality of layers and is cut in a specific plane. Of the hard coating layer, when T1 is the thickness of the thinnest part of the edge of the cutting edge and T2 is a thickness 1 mm away from the edge of the cutting edge in the rake face direction, the surface of the hard coating layer satisfies T1 <T2. , When the point a distance Da away from the edge of the cutting edge in the rake face direction is a and the point a distance Db away in the flank direction is b, Da and Db satisfy a specific numerical range, and the point a Of the crystal grains constituting the hard coating layer in a region of 10% or more of the region E occupying the thickness of 0.1T1 to 0.9T1 from the surface in the hard coating layer from to b. There By less than 5 degrees 10 degrees or more, excellent wear resistance and chipping resistance are disclosed to be obtained.

Patent Document 2 discloses a composite nitriding of Al and Ti that satisfies the composition formula (Ti _1-x Al _x ) N (wherein x is 0.40 to 0.60 in atomic ratio) on the tool base surface. When the crystal orientation analysis by EBSD is performed on the composite nitride layer, the area of crystal grains having a crystal orientation <110> within a range of 0 to 15 degrees from the normal direction of the surface polished surface Al showing a crystal arrangement in which the ratio is 50% or more and the ratio of small-angle grain boundaries (0 <θ ≦ 15 °) is 50% or more when the angle between adjacent crystal grains is measured. It is disclosed that a hard coating layer made of a composite nitride layer of Ti and Ti is formed by vapor deposition, so that the hard coating layer exhibits excellent fracture resistance even under heavy cutting conditions.

However, although the above-described coated tool is disclosed for depositing TiAlN as a hard coating layer, there is no disclosure or suggestion about increasing the Al content ratio x to 0.65 or more.
From such a viewpoint, a technique for increasing the Al content ratio x to about 0.9 by forming a hard coating layer by a chemical vapor deposition method has also been proposed.

For example, Patent Document 3 discloses that a 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. coating the thereby formed since it is an object to improve the heat insulating effect, it enhanced the value of the proportion x of Al to _{0.65 ~ 0.95 (Ti 1-x} Al x) N layer It is not clear what kind of influence the cutting performance has.

Further, for example, in Patent Document 4, a TiCN layer and an Al ₂ O ₃ layer are used as an inner layer, and a cubic structure (Ti _1-x Al) having a cubic structure or a hexagonal structure is formed thereon by chemical vapor deposition. _x ) N layer (wherein x is 0.65 to 0.90 in atomic ratio) is coated as an outer layer, and a compressive stress of 100 to 1100 MPa is applied to the outer layer, whereby the heat resistance and fatigue strength of the coated tool It has been proposed to improve.

Further, for example, Patent Document 5 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. An element, at least one element selected from the group consisting of the periodic table 4a, 5a, 6a group elements and Si, and at least one element selected from the group consisting of carbon, nitrogen, oxygen and boron. It has been proposed to drastically improve the wear resistance and oxidation resistance of the hard coating layer by including a compound and chlorine.

For example, Patent Document 6 discloses a hard coating composed of a lower layer, an intermediate layer, and an upper layer on the surface of a tool base in order to improve chipping resistance and wear resistance in high-speed intermittent cutting such as stainless steel and Ti alloy. The lower layer has a predetermined average layer thickness, and includes a Ti _1-X Al _X N layer, a Ti _1-X Al _X C layer, a Ti _1-X Al _X CN layer (X is Al The content ratio (atomic ratio) of 0.65 ≦ X ≦ 0.95) is composed of a TiAl compound having a cubic structure consisting of one or more layers, and the intermediate layer has a predetermined average layer thickness. And a Cr _1-Y Al _Y N layer, a Cr _1-Y Al _Y C layer, a Cr _1-Y Al _Y CN layer (Y is the Al content (atomic ratio), and 0.60 ≦ Y ≦ 0.90) CrAl having a cubic structure consisting of one or more layers Composed of objects, improving the upper layer, by configuring in Al ₂ O ₃ having a predetermined average thickness, to improve the adhesion strength of the lower layer and the upper layer, thereby, the chipping resistance and abrasion resistance It has been proposed to let

Patent Document 7 discloses that a lower layer, an intermediate layer, and an upper layer are formed on the surface of a tool base in order to improve chipping resistance and wear resistance in high-speed intermittent cutting of heat-resistant alloys such as precipitation hardening stainless steel and Inconel. And a lower layer is a Ti _1-X Al _X N layer, a Ti _1-X Al _X C layer, a Ti _1-X Al _X CN layer (X is Al The atomic ratio is 0.65 ≦ X ≦ 0.95) and is composed of a Ti compound having a cubic crystal structure consisting of one layer or two or more layers, and the intermediate layer is a predetermined single layer average layer Thick Cr _1-Y Al _Y N layer, Cr _1-Y Al _Y C layer, Cr _1-Y Al _Y CN layer (Y represents the Al content and represents the atomic ratio, 0.60 ≦ Y ≦ 0. 90) having a cubic crystal structure consisting of one or more layers. constituted by r compound, by the upper layer composed of Al ₂ O ₃ with an average layer thickness with a predetermined pore size and pore density micro pores of, improves the adhesion strength of the lower layer and the upper layer The upper layer is made of an Al ₂ O ₃ layer having micropores having a predetermined pore diameter and pore density, thereby reducing mechanical and thermal shocks, thereby improving chipping resistance and wear resistance. It has been proposed.

Further, in Patent Document 8, in order to increase the fracture resistance of a hard coating layer in heavy cutting of steel or cast iron in which a high load acts on the cutting edge, (Al _1-X Cr _X ) N (where X is an atomic ratio, X = 0.3 to 0.6) is provided with a hard coating layer, and the normal of the {100} plane with respect to the normal of the surface polished surface of the tool substrate In the inclination angle frequency distribution graph created by measuring the inclination angle formed by, the highest peak exists in the inclination angle section of 30 to 40 degrees, the total frequency is 60% or more of the whole, and the surface polished surface In the constituent atomic shared lattice distribution graph created by measuring the inclination angle formed by the normal of the {112} plane with respect to the normal of Σ3, the highest peak exists at Σ3, and the distribution ratio is 50% or more of the whole By forming the crystal orientation and constituent atomic shared lattice distribution form (Al _{1-X Cr X)} to improve the high temperature strength of the _N layer, has been, it has been proposed to improve the fracture resistance of the hard coating layer in the heavy cutting.

Japanese Unexamined Patent Publication No. 2012-20391 (A) Japanese Unexamined Patent Publication No. 2010-17785 (A) Japan Special Table 2011-516722 Publication (A) Japanese National Table 2011-513594 (A) Japanese Unexamined Patent Publication No. 2006-82207 (A) Japanese Unexamined Patent Publication No. 2014-208394 (A) Japanese Unexamined Patent Publication No. 2014-198362 (A) Japanese Unexamined Patent Publication No. 2009-56539 (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, the coated tools described in

Patent Documents

1 and 2 do not consider increasing the Al content ratio x of the hard coating layer composed of the (Ti _1-x Al _x ) N layer. When subjected to the high-speed intermittent cutting, there is a problem that it cannot be said that the wear resistance and chipping resistance are sufficient.
On the other hand, for the (Ti _1-x Al _x ) N layer formed by the chemical vapor deposition method described in Patent Document 3, the Al content ratio x can be increased and a cubic structure can be formed. Therefore, although a hard coating layer having a predetermined hardness and excellent wear resistance can be obtained, there is a problem that the toughness is inferior.
Furthermore, although the coated tool described in Patent Document 4 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 5 is intended to improve wear resistance and oxidation resistance, but chipping resistance is effective under cutting conditions involving impact such as high-speed interrupted cutting. There was a problem that the sex was not enough.

In addition, the coated tool described in

Patent Documents

6 and 7 improves the adhesion strength between the lower layer and the upper layer by interposing a CrAl compound and a Cr compound as an intermediate layer of the hard coating layer, Although the chipping resistance is improved, the strength and hardness of the CrAl compound and the Cr compound itself are not sufficient, so that the chipping resistance and wear resistance are sufficient when subjected to high-speed intermittent cutting. I can't say that.
In the coated tool described in Patent Document 8, the Cr content ratio of the hard coating layer made of (Al _1-X Cr _X ) N is adjusted, and the crystal orientation and constituent atomic shared lattice point distribution are adjusted. By controlling the form, the strength of the hard coating layer can be improved, and as a result, the chipping resistance and chipping resistance can be improved, but the strength of the (Al _1-X Cr _X ) N layer Since the hardness is not sufficient, excellent chipping resistance and wear resistance cannot be exhibited over a long period of use, and there is a problem that the tool life is short in high-speed intermittent cutting of alloy steel.

Therefore, the technical problem to be solved by the present invention, that is, the object of the present invention is to generate high heat in carbon steel, alloy steel, cast iron and the like, and to perform high-speed intermittent operation with an impact load on the cutting edge. Even when it is used for cutting or the like, it is to provide a coated tool that has a hard coating layer with excellent toughness and exhibits excellent chipping resistance and wear resistance over a long period of 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 ) ”), and a composite nitride or composite carbonitride of Cr and Al (hereinafter referred to as“ (Cr, Al) (C, N) ”or“ (Cr _1-p Al _p ) (sometimes indicated by C _q N _1-q ) ”), earnestly researched to improve the chipping resistance and wear resistance of the coated tool formed by vapor deposition. As a result, the following knowledge was obtained.

That is, it includes at least one conventional (Ti _1-x Al _x ) (C _y N _1-y ) layer, (Cr _1-p Al _p ) (C _q N _1-q ) layer, and has a predetermined average The hard coating layer having a layer thickness includes a (Ti _1-x Al _x ) (C _y N _1-y ) layer and a (Cr _1-p Al _p ) (C _q N _1-q ) layer perpendicular to the tool substrate When formed in a columnar shape, it has high wear resistance. On the other hand, as the anisotropy of the (Ti _1-x Al _x ) (C _y N _1-y ), (Cr _1-p Al _p ) (C _q N _1-q ) layer increases, (Ti _1-x Al ₁ _x ) (C _y N _1-y ), (Cr _1-p Al _p ) (C _q N _1-q ) layers have decreased toughness, and as a result, chipping resistance and chipping resistance have been reduced. It cannot be said that sufficient wear resistance can be exhibited over use, and the tool life is not satisfactory.
Therefore, the present inventors have earnestly studied the (Ti _1-x Al _x ) (C _y N _1-y ) and (Cr _1-p Al _p ) (C _q N _1-q ) layers constituting the hard coating layer. As a result of research, due to the following completely new ideas (1) to (3), distortion is caused in crystal grains having a NaCl-type face-centered cubic structure (hereinafter sometimes simply referred to as “cubic structure”). As a result, the inventors have succeeded in improving both 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.
(1) The (Ti _1-x Al _x ) (C _y N _1-y ) layer, which is a composite nitride or composite carbonitride of Ti and Al, contains crystal grains having a NaCl-type face-centered cubic structure, An idea to make the average orientation difference in crystal grains of a crystal grain having a cubic structure more than 2 degrees. (2) A kind of element selected from Si, Zr, B, V, Cr in the hard coating layer (hereinafter referred to as “Me”). (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) layer which is a composite nitride or composite carbonitride of Ti, Al and Me The idea of containing crystal grains having a face-centered cubic structure and having an average misorientation within the grain of the cubic grains of 2 degrees or more. (3) With a composite nitride or composite carbonitride of Cr and Al there _{_{_{(Cr 1-p Al p)}}} (C q N 1-q) layer have a face-centered cubic structure of NaCl type That idea to the grain in the average misorientation of grains more than once with the content and the standing-cubic structure grain

Furthermore, in the columnar crystal grains, a novel finding that both the chipping resistance and the wear resistance are further improved by increasing the ratio of the {110} orientation on the surface side of the film than on the surface side of the tool base. I also found.

Specifically, the hard coating layer is
(1) When containing at least a composite nitride or composite carbonitride layer of Ti and Al and expressed by a composition formula: (Ti _1-x Al _x ) (C _y N _1-y ), in particular, Ti of Al The average content ratio x _avg in the total amount of Al and the average content ratio y _avg in the total amount of C and N in C (where x _avg and y _avg are atomic ratios) are respectively 0.60 ≦ x _{When avg} ≦ 0.95 and 0 ≦ y _avg ≦ 0.005 are satisfied, there are crystals having a cubic structure in the crystal grains constituting the composite nitride or carbonitride layer, and the crystal orientation of the crystal grains Is analyzed from the longitudinal cross-sectional direction using an electron beam backscattering diffractometer, and the average orientation difference in each crystal grain is obtained. When the area ratio of the composite or composite carbonitride layer is 20% or more, the cubic structure It can give rise to distortion in the crystal grains having,
(2) At least a composite nitride or composite carbonitride layer of Ti, Al, and Me (where Me is a kind of element selected from Si, Zr, B, V, and Cr), and a composition formula: ( Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ), in particular, the average content ratio α _avg in the total amount of Ti, Al and Me in Al and Ti and Al in Me The average content ratio β _avg in the total amount of Me and the average content ratio γ _avg in the total amount of C and N in C (wherein α _avg , β _avg , and γ _avg are all atomic ratios) are 0. When satisfying 60 ≦ α _avg , 0.005 ≦ β _avg ≦ 0.10, 0 ≦ γ _avg ≦ 0.005, 0.605 ≦ α _avg + β _avg ≦ 0.95, composite nitride or composite carbonitride Having cubic structure in the crystal grains constituting the layer The crystal orientation of the crystal grains present is analyzed from the longitudinal cross-sectional direction using an electron beam backscattering diffractometer, and the average orientation difference within the crystal grains is found to be 2 degrees. The presence of 20% or more of the crystal grains showing the above in the area ratio of the composite nitride or the composite carbonitride layer can cause distortion in the crystal grains having a cubic structure,
(3) When at least a composite nitride or composite carbonitride layer of Cr and Al is included and expressed by a composition formula: (Cr _1-p Al _p ) (C _q N _1-q ), in particular, Cr of Al The average content ratio p _avg in the total amount of Al and the average content ratio q _avg in the total amount of C and N in C (wherein p _avg and q _avg are atomic ratios) are respectively 0.70 ≦ p _{When avg} ≦ 0.95 and 0 ≦ q _avg ≦ 0.005 are satisfied, some of the crystal grains constituting the composite nitride or composite carbonitride layer have a cubic structure, and the crystal orientation of the crystal grains Is analyzed from the longitudinal cross-sectional direction using an electron beam backscattering diffractometer, and the average orientation difference in each crystal grain is obtained. When the area ratio of the composite or composite carbonitride layer is 20% or more, the cubic structure It can give rise to distortion in the crystal grains having,
(4) Further, in any of the above (1) to (3), by increasing the ratio of the {110} orientation on the surface side of the film compared to the surface side of the tool substrate, the chipping resistance, Abrasion is improved,
As a result, it has been found that the cutting tool having such a hard coating layer exhibits excellent wear resistance over a long period of time.

Then, the (Ti _1-x Al _x ) (C _y N _1-y ) layer, (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) layer, (Cr Each of the _1-p Al _p ) (C _q N _1-q ) layers can be formed by, for example, the following chemical vapor deposition method in which the reaction gas composition is periodically changed on the tool base surface.

(1) (Ti _1-x Al _x ) (C _y N _1-y ) Layer The chemical vapor deposition reactor used is a gas group A composed of NH ₃ , N ₂ and H ₂ , TiCl ₄ , Al (CH ₃ ) A gas group B composed of ₃ , AlCl ₃ , N ₂ , H ₂ is supplied into the reactor from a separate gas supply pipe, and supply of the gas group A and the gas group B into the reactor is, for example, Supply gas so that gas flows for a time shorter than that period at a constant time interval, and the gas supply of gas group A and gas group B has a phase difference that is shorter than the gas supply time. The reaction gas composition on the surface of the tool base can be temporally changed from the gas group A, the mixed gas of the gas group A and the gas group B, and the gas group B. 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, the gas supply port is rotated, the tool base is rotated, the tool base is reciprocated, the reaction gas composition on the surface of the tool base is changed to the gas group A as the main. The mixed gas (first reaction gas), the mixed gas of gas group A and gas group B (second reaction gas), and the mixed gas mainly composed of gas group B (third reaction gas) are changed over time. But it can be realized.
On the surface of the tool base, the reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) is, for example, NH ₃ : 3.5 to 4.0% as the gas group A, N ₂ : 1.0. -2.0%, H ₂ : 55-60%, gas group B as AlCl ₃ : 0.6-0.9%, TiCl ₄ : 0.2-0.3%, Al (CH ₃ ) ₃ : 0 ~ 0.5%, N ₂ : 12.5 to 15.0%, H ₂ : remaining, reaction atmosphere pressure: 4.5 to 5.0 kPa, reaction atmosphere temperature: 700 to 900 ° C, supply cycle 1 to 5 seconds By performing the thermal CVD method for a predetermined time, with a gas supply time of 0.15 to 0.25 seconds per cycle and a phase difference of 0.10 to 0.20 seconds of supply of gas group A and gas group B, A (Ti _1-x Al _x ) (C _y N _1-y ) layer having a predetermined target layer thickness is formed.
Then, as described above, the gas group A and the gas group B are supplied so that there is a difference in the time required to reach the tool base surface, and NH ₃ as the nitrogen source gas in the gas group A is 3.5 to 4.0%. The metal chloride raw material or carbon raw material AlCl ₃ in the gas group B: 0.6 to 0.9%, TiCl ₄ : 0.2 to 0.3%, Al (CH ₃ ) ₃ : 0 to 0 By setting the ratio to 5%, local unevenness of the composition in the crystal grains, local distortion of the crystal lattice due to the introduction of dislocations and point defects, and the surface side of the tool base and the film surface of the crystal grains are formed. The degree of {110} orientation at 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.

(2) (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) Layer 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 , and H ₂ are supplied into the reactor from respective gas supply pipes, and the gas group Supply of A and gas group B into the reaction apparatus is performed, for example, by supplying gas so that gas flows for a time shorter than that period at a constant time interval. Changes the composition of the reaction gas on the surface of the tool base with the gas group A, the mixed gas of the gas group A and the gas group B, and the gas group B in such a manner that a phase difference shorter than the gas supply time occurs. be able to. 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, the gas supply port is rotated, the tool base is rotated, the tool base is reciprocated, the reaction gas composition on the surface of the tool base is changed to the gas group A as the main. The gas mixture (first reaction gas), the gas mixture of gas group A and gas group B (second reaction gas), and the gas mixture mainly consisting of gas group B (third reaction gas) can be changed over time. It can be realized.
On the surface of the tool base, the reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) is, for example, NH ₃ : 3.5 to 4.0% as the gas group A, N ₂ : 1.0. -2.0%, H ₂ : 55-60%, gas group B as AlCl ₃ : 0.6-0.9%, TiCl ₄ : 0.2-0.3%, MeCl _n (Me chloride) : 0.1 to 0.2%, Al (CH ₃ ) ₃ : 0 to 0.5%, N ₂ : 12.5 to 15.0%, H ₂ : remaining, reaction atmosphere pressure: 4.5 to 5 0.0 kPa, reaction atmosphere temperature: 700 to 900 ° C., supply cycle 1 to 5 seconds, gas supply time per cycle 0.15 to 0.25 seconds, phase difference of supply of gas group A and gas group B 0.10 By performing the thermal CVD method for a predetermined time of ˜0.20 seconds, (Ti _1−α−β Al _α Me _β ) ( C _γ N _1-γ ) layer is formed.
Then, as described above, the gas group A and the gas group B are supplied so that there is a difference in the time required to reach the tool base surface, and NH ₃ as the nitrogen source gas in the gas group A is 3.5 to 4.0%. The metal chloride raw material or carbon raw material AlCl ₃ in the gas group B: 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 : Set to 0 to 0.5%, so that local compositional unevenness, dislocations and point defects in the crystal grains are introduced locally in the crystal grains. And 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.

(3) Regarding the (Cr _1-p Al _p ) (C _q N _1-q ) layer The chemical vapor deposition reactor used includes a gas group A composed of NH ₃ , N ₂ and H ₂ , CrCl ₃ , AlCl ₃ , A gas group B composed of Al (CH ₃ ) ₃ , N ₂ , and H ₂ is supplied into the reactor from a separate gas supply pipe, and supply of the gas group A and the gas group B into the reactor is, for example, Supply gas so that gas flows for a time shorter than that period at a constant time interval, and the gas supply of gas group A and gas group B has a phase difference that is shorter than the gas supply time. The reaction gas composition on the surface of the tool base can be temporally changed from the gas group A, the mixed gas of the gas group A and the gas group B, and the gas group B. 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, the gas supply port is rotated, the tool base is rotated, the tool base is reciprocated, the reaction gas composition on the surface of the tool base is changed to the gas group A as the main. The mixed gas (first reaction gas), the mixed gas of gas group A and gas group B (second reaction gas), and the mixed gas mainly composed of gas group B (third reaction gas) are changed over time. But it can be realized.
On the surface of the tool base, the reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) is, for example, NH ₃ : 3.5 to 4.0% as the gas group A, N ₂ : 1.0. ~ 2.0%, H ₂ : 55 ~ 60%, gas group B as AlCl ₃ : 0.6 ~ 0.9%, CrCl ₃ : 0.2 ~ 0.3%, Al (CH ₃ ) ₃ : 0 ∼0.5%, N ₂ : 12.5 to 15.0%, H ₂ : remaining, reaction atmosphere pressure: 4.5 to 5.0 kPa, reaction atmosphere temperature: 750 to 900 ° C, supply cycle 1 to 5 seconds By performing the thermal CVD method for a predetermined time, assuming that the gas supply time per cycle is 0.15 to 0.25 seconds and the phase difference between the gas group A and the gas supply B is 0.10 to 0.20 seconds, A (Cr _1-p Al _p ) (C _q N _1-q ) layer having a predetermined target layer thickness is formed.
Then, as described above, the gas group A and the gas group B are supplied so that there is a difference in the time required to reach the tool base surface, and NH ₃ as the nitrogen source gas in the gas group A is 3.5 to 4.0%. The metal chloride raw material or carbon raw material AlCl ₃ in the gas group B: 0.6 to 0.9%, CrCl ₃ : 0.2 to 0.3%, Al (CH ₃ ) ₃ : 0 to 0 By setting the ratio to 5%, local unevenness of the composition in the crystal grains, local distortion of the crystal lattice due to the introduction of dislocations and point defects, and the surface side of the tool base and the film surface of the crystal grains are formed. The degree of {110} orientation at 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 aspect shown below.
(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, and cubic boron nitride-based ultrahigh-pressure sintered body In the tool,
(A) The hard coating layer is composed of a composite nitride or composite carbonitride layer of Ti and Al having an average layer thickness of 2 to 20 μm, or Ti, Al, and Me (where Me is Si, Zr, B, V A composite nitride or composite carbonitride layer of one element selected from Cr), or at least one of a composite nitride or composite carbonitride layer of Cr and Al,
(B) The composite nitride or composite carbonitride layer includes at least a composite nitride or composite carbonitride phase having a NaCl-type face-centered cubic structure,
(C) The crystal orientation of the crystal grains having the NaCl-type face-centered cubic structure among the crystal grains constituting the composite nitride or composite carbonitride layer is determined from the longitudinal sectional direction using an electron beam backscattering diffractometer. When the average orientation difference in each crystal grain is analyzed and the average orientation difference in each crystal grain is 2 degrees or more, the crystal grains having an average orientation difference in the crystal grain of 2 degrees or more are 20 in terms of the area ratio with respect to the total area of the composite nitride or composite carbonitride layer. % Exist,
(D) Furthermore, the inclination angle formed by the normal of the {110} plane, which is the crystal plane with respect to the normal direction of the tool substrate surface of the crystal grain, is equal to the composite nitride or the composite carbonitride layer in the layer thickness direction. The measured tool base side area and the surface side area are measured separately, and the measured tilt angle within the range of 0 to 45 degrees with respect to the normal direction among the measured tilt angles is 0.25 degrees. If you divide by pitch and count the frequency that exists in each division,
In the region on the tool base side, when the total of the frequencies existing in the range of 0 to 12 degrees is M _deg with respect to the total frequencies in the tilt angle frequency distribution, M _deg is 10 to 40%,
In the region on the surface side, the highest peak is present in the inclination angle section within the range of 0 to 12 degrees, and the total of the frequencies existing within the range of 0 to 12 degrees is relative to the entire frequency in the inclination angle frequency distribution. When the ratio of the Te and the N _deg, the surface-coated cutting tool N _deg is characterized in that it is a _{_{M deg + 10 ~ M deg +}} 30%.
(2) The composite nitride or composite carbonitride layer is a composite nitride or composite carbonitride layer of Ti and Al, the composition of which is
Composition formula: (Ti _1-x Al _x ) (C _y N _1-y )
In the composite nitride or composite carbonitride layer, the average content ratio x _avg in the total content of Ti and Al in Al and the average content ratio y _avg in the total content of C and N in C (where x _avg and y _avg are both atomic ratios) satisfying 0.60 ≦ x _avg ≦ 0.95 and 0 ≦ y _avg ≦ 0.005, respectively. Cutting tools.
(3) The composite nitride or composite carbonitride layer is composed of Ti, Al, and Me (where Me is a kind of element selected from Si, Zr, B, V, and Cr). A carbonitride layer, the composition of which is
Composition formula: (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ )
In the composite nitride or composite carbonitride layer, the average content ratio α _avg in the total amount of Ti, Al, and Me of Al, the average content ratio β _avg in the total amount of Me Ti, Al, and Me And the average content ratio γ _avg (where α _avg , β _avg , and γ _avg are atomic ratios) of the total amount of C and N in C and C are 0.60 ≦ α _avg and 0.005 ≦ β _avg , respectively. ≦ 0.10, 0 ≦ γ _avg ≦ 0.005, 0.605 ≦ α _avg + β _avg ≦ 0.95 is satisfied, The surface-coated cutting tool according to (1) above.
(4) The composite nitride or composite carbonitride layer is a composite nitride or composite carbonitride layer of Cr and Al, the composition of which
Composition formula: (Cr _1-p Al _p ) (C _q N _1-q )
In the composite nitride or composite carbonitride layer, the average content ratio p _avg in the total content of Cr and Al in Al and the average content ratio q _avg in the total content of C and N in C (p, _avg and q _avg are both atomic ratios) satisfying 0.70 ≦ p _avg ≦ 0.95 and 0 ≦ q _avg ≦ 0.005, respectively. Cutting tools.
(5) The composite nitride or composite carbonitride layer contains at least 70 area% or more of a composite nitride or composite carbonitride phase having a NaCl type face centered cubic structure. The surface coating cutting tool in any one of thru | or (4).
(6) The composite nitride or composite carbonitride layer is an individual crystal having a NaCl-type face-centered cubic structure in the composite nitride or composite carbonitride layer when observed from the longitudinal section direction of the layer. The surface-coated cutting tool according to any one of (1) to (5) above, which has a columnar structure having an average particle width W of 0.1 to 2 μm and an average aspect ratio A of 2 to 10 .
(7) One of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer and carbonitride layer between the tool base and the composite nitride or composite carbonitride layer, or The surface-coated cutting tool according to any one of (1) to (6) above, wherein there is a lower layer composed of two or more Ti compound layers and having a total average layer thickness of 0.1 to 20 μm. .
(8) The above (1) to (1), wherein an upper layer including at least an aluminum oxide layer is formed 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 7).
(9) The composite nitride or the composite carbonitride layer is formed by a chemical vapor deposition method containing at least trimethylaluminum as a reaction gas component, according to any one of (1) to (8), The manufacturing method of the surface coating cutting tool of description.
The “inside crystal grain average orientation difference” means a GOS (Grain Orientation Spread) value described later.

In the surface-coated cutting tool which is an embodiment of the present invention (hereinafter referred to as “the surface-coated cutting tool of the present invention” or “the cutting tool of the present invention”), the surface-coated cutting provided with a hard coating layer on the surface of the tool base. In the tool, the hard coating layer is composed of a composite nitride or composite carbonitride layer of Ti and Al having an average layer thickness of 2 to 20 μm, or Ti, Al and Me (where Me is Si, Zr, B, V, A composite nitride or composite carbonitride layer of one element selected from Cr), or a composite nitride or composite carbonitride layer of Cr and Al, and a composite nitride or composite Some of the crystal grains constituting the carbonitride layer have a cubic structure, and the crystal orientation of the crystal grains is analyzed from the longitudinal cross-sectional direction using an electron beam backscattering diffractometer. When the average difference in orientation is calculated A crystal grain having an average orientation difference within a crystal grain of 2 degrees or more is present in an area ratio of 20% or more with respect to the entire composite nitride or composite carbonitride layer. The inclination angle formed by the normal line of the {110} plane, which is a plane, is measured by dividing the composite nitride or composite carbonitride layer into two parts in the layer thickness direction, the tool base side region and the surface side region, When the measured tilt angles within the range of 0 to 45 degrees with respect to the normal direction among the measured tilt angles are divided into pitches of 0.25 degrees and the frequencies existing in each section are tabulated, a) In the region on the tool base side, if the total frequency within the range of 0 to 12 degrees is M _deg with respect to the total frequency in the tilt angle frequency distribution, M _deg is 10 to 40%. B) In the area on the surface side, the slope angle is within the range of 0 to 12 degrees. With peaks exist, the sum of the frequencies present in the range of the 0-12 degrees, when the ratio of the relative total power at the inclination angle frequency distribution and N _deg, N _deg is M _{_deg} + 10 ~ M _deg +30 And the average grain width W of the individual crystal grains having a cubic structure in the composite nitride or composite carbonitride layer when the composite nitride or composite carbonitride layer is observed from the film cross-section side. Having a columnar structure having an average aspect ratio A of 2 to 10 causes distortion in crystal grains having a cubic structure, and has a (110) orientation. The hardness and toughness of the grains are improved. As a result, the effect of improving the chipping resistance without impairing the wear resistance is exhibited. Compared with the conventional hard coating layer, it exhibits excellent cutting performance over a long period of use, and the length of the coated tool is improved. Life expectancy is achieved.

The schematic explanatory drawing of the measuring method of the crystal grain average orientation difference of the crystal grain which has the NaCl type face center cubic structure (cubic crystal) of the composite nitride of Ti and Al of this invention coated tool or a composite carbonitride layer is shown. . It is the film | membrane structure schematic diagram which represented typically the cross section of the composite nitride of Ti and Al, or the composite carbonitride layer which comprises the hard coating layer which the surface coating cutting tool of this invention has. In the cross section of the composite nitride layer or composite carbonitride layer of Ti and Al constituting the hard coating layer of the coated tool of the present invention, the average grain orientation difference (GOS value) of individual grains having a cubic structure An example of the histogram about an area ratio is shown. The dotted line in the vertical direction in the histogram indicates a boundary line having an average orientation difference within the grain of 2 °. In FIG. 3, the bar on the right side of the dotted line in the vertical direction has an average orientation difference within the grain of 2 ° or more. Show things. In the cross section of the composite nitride layer or composite carbonitride layer of Ti and Al constituting the hard coating layer of the comparative coated tool, the average grain orientation difference (GOS value) of individual grains having a cubic structure An example of the histogram about an area ratio is shown. The dotted line in the vertical direction in the histogram indicates a boundary line having an average orientation difference within the grain of 2 °, and the bar on the right side of the dotted line in the vertical direction in FIG. 4 has an average orientation difference within the grain of 2 ° or more. Show things. It is an example of the inclination angle number distribution graph of the {110} plane produced in the area | region of the tool base | substrate side of the composite nitride of Ti and Al or the composite carbonitride layer which comprises the hard coating layer of this invention coated tool. The count frequency is shown as a relative value normalized with the maximum count frequency as 100. It is an example of the inclination angle number distribution graph of the {110} plane created in the area | region of the surface side of the composite nitride of Ti and Al or the composite carbonitride layer which comprises the hard coating layer of this invention coated tool. The count frequency is shown as a relative value normalized with the maximum count frequency as 100. In the cross section of the composite nitride layer or composite carbonitride layer of Ti, Al, and Me constituting the hard coating layer of the coated tool of the present invention, the average difference in crystal orientation (GOS value) of the individual grains having a cubic structure ) Shows an example of a histogram for the area ratio. The dotted line in the vertical direction in the histogram indicates a boundary line having an average misorientation within the grain of 2 °, and the bar on the right side of the dotted line in the vertical direction in FIG. 7 has an average misorientation within the grain of 2 ° or more. Show things. In the cross-section of the composite nitride layer or composite carbonitride layer of Ti, Al, and Me constituting the hard coating layer of the comparative coated tool, the average grain orientation difference (GOS value) of the individual grains having a cubic structure ) Shows an example of a histogram for the area ratio. A dotted line in the vertical direction in the histogram indicates a boundary line having an average misorientation within the grain of 2 °, and a bar on the right side of the dotted line in the vertical direction in FIG. Show things. It is an example of the inclination angle number distribution graph of the {110} plane created in the area | region on the tool base | substrate side of the composite nitride of Ti, Al, and Me or the composite carbonitride layer which comprises the hard coating layer of this invention coated tool. . The count frequency is shown as a relative value normalized with the maximum count frequency as 100. It is an example of the inclination angle number distribution graph of the {110} plane produced in the area | region of the surface side of the composite nitride of Ti, Al, and Me or the composite carbonitride layer which comprises the hard coating layer of this invention coated tool. The count frequency is shown as a relative value normalized with the maximum count frequency as 100. In the cross section of the composite nitride layer or composite carbonitride layer of Cr and Al constituting the hard coating layer of the coated tool of the present invention, the average orientation difference (GOS value) within the grains of the individual grains having a cubic structure An example of the histogram about an area ratio is shown. A dotted line in the vertical direction in the histogram indicates a boundary line having an average orientation difference within the grain of 2 °, and a bar on the right side of the dotted line in the vertical direction in FIG. 11 has an average orientation difference within the grain of 2 ° or more. Show things. Comparative Example In the cross section of the composite nitride layer or composite carbonitride layer of Cr and Al constituting the hard coating layer of the coated tool, the average orientation difference (GOS value) within the grains of the individual grains having a cubic structure An example of the histogram about an area ratio is shown. The dotted line in the vertical direction in the histogram indicates a boundary line having an average misorientation within the grain of 2 °, and the bar on the right side of the dotted line in the vertical direction in FIG. Show things. It is an example of the inclination angle number distribution graph of the {110} plane created in the area | region of the tool base | substrate side of the composite nitride of Cr and Al or the composite carbonitride layer which comprises the hard coating layer of this invention coated tool. The count frequency is shown as a relative value normalized with the maximum count frequency as 100. It is an example of the inclination angle number distribution graph of the {110} plane created in the area | region of the surface side of the composite nitride or composite carbonitride layer of Cr and Al which comprises the hard coating layer of this invention coated tool. The count frequency is shown as a relative value normalized with the maximum count frequency as 100.

The form for implementing this invention is demonstrated below.

Average layer thickness of the composite nitride or composite carbonitride layer constituting the hard coating layer:
The hard coating layer of the surface-coated cutting tool of the present invention is a chemical vapor-deposited Ti and Al composite nitride or composite carbonitride layer (composition formula: (Ti _1-x Al _x ) (C _y N _{1- 1 y)),} or a composite nitride of Ti and Al and Me or composite carbonitride layer (composition _{formula: (Ti 1-α-β} Al α Me β) (C γ N 1-γ)), or, Cr And a composite nitride or composite carbonitride layer (composition formula: (Cr _1-p Al _p ) (C _q N _1-q )) of Al and Al. This composite nitride or composite carbonitride layer has high hardness and excellent wear resistance, but the effect is particularly remarkable when the average layer thickness is 2 to 20 μm. The reason is that if the average layer thickness is less than 2 μm, the layer thickness is so thin that it may not be possible to ensure sufficient wear resistance over a long period of use, while if the average layer thickness exceeds 20 μm, The crystal grains of the composite nitride or composite carbonitride layer of Ti and Al are likely to be coarsened, and chipping is likely to occur. Therefore, the average layer thickness is set to 2 to 20 μm.

Composition of composite nitride or composite carbonitride layer constituting hard coating layer:
(1) When the Ti—Al composite nitride or composite carbonitride of the present invention is expressed by a composition formula: (Ti _1-x Al _x ) (C _y N _1-y ), the combination of Al Ti and Al The average content ratio x _{avg in the} amount and the average content ratio y _avg in the total amount of C and N in C (where x _avg and y _avg are atomic ratios) are respectively 0.60 ≦ x _avg ≦ 0 .95, 0 ≦ y _avg ≦ 0.005 is preferably controlled.
This is because, when the average content x _avg of Al is less than 0.60, since a composite nitride of Ti and Al or composite carbonitride layer is poor in hardness, and subjected to high speed interrupted cutting, such as alloy steel In some cases, the wear resistance is not sufficient. On the other hand, when the average content ratio x _{avg of} Al exceeds 0.95, the content ratio of Ti is relatively decreased, so that embrittlement is caused and chipping resistance is deteriorated. Therefore, the average Al content ratio x _avg was determined to be 0.60 ≦ x _avg ≦ 0.95.
Further, when the content ratio (atomic ratio) y _avg of the C component contained in the composite nitride or the composite carbonitride layer is a minute amount in the range of 0 ≦ y _avg ≦ 0.005, the composite nitride or the composite carbonitride The adhesion between the material layer and the tool base or the lower layer is improved and the lubricity is improved to reduce the impact during cutting. As a result, the fracture resistance and resistance of the composite nitride or composite carbonitride layer are reduced. Chipping property is improved. On the other hand, if the average content ratio y _{avg of the} component C deviates from the range of 0 ≦ y _avg ≦ 0.005, the toughness of the composite nitride or composite carbonitride layer decreases, so that the chipping resistance and chipping resistance are reversed. Since it falls, it is not preferable. Therefore, the average content ratio y _avg of the C component was set to 0 ≦ y _avg ≦ 0.005.
(2) About the composite nitride or composite carbonitride of Ti, Al and Me of the present invention When expressed by the composition formula: (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) , Me is a kind of element selected from Si, Zr, B, V, and Cr), the average content ratio α _avg in the total amount of Ti, Al, and Me in Al, and the combination of Ti, Al, and Me in Me The average content ratio β _{avg in the} amount and the average content ratio γ _avg in the total amount of C and N in C (where α _avg , β _avg , and γ _avg are all atomic ratios) are 0.60 ≦ α It is preferable to control so as to satisfy _avg , 0.005 ≦ β _avg ≦ 0.10, 0 ≦ γ _avg ≦ 0.005, 0.605 ≦ α _avg + β _avg ≦ 0.95.
The reason is that when the average Al content ratio α _avg is less than 0.60, the composite nitride or composite carbonitride layer of Ti and Al and Me is inferior in hardness, so it is suitable for high-speed intermittent cutting of alloy steel and the like. If provided, the wear resistance is not sufficient.
Further, when the average content ratio β _{avg of} Me is less than 0.005, the composite nitride of Ti, Al, and Me or the composite carbonitride layer is inferior in hardness, and thus subjected to high-speed intermittent cutting of alloy steel and the like. In some cases, the wear resistance is not sufficient. On the other hand, if it exceeds 0.10, the segregation of Me to the grain boundaries, etc., the toughness of the composite nitride or composite carbonitride layer of Ti, Al, and Me will decrease, and it will be subjected to high-speed intermittent cutting of alloy steel etc. The chipping resistance is not sufficient. Therefore, the average content ratio β _avg of Me was defined as 0.005 ≦ β _avg ≦ 0.10.
On the other hand, if the sum α _avg + β _avg of the average content ratio α _{avg of} Al and the average content ratio β _{avg of} Me is less than 0.605, the hardness of the composite nitride or composite carbonitride layer of Ti, Al, and Me Therefore, when it is subjected to high-speed intermittent cutting of alloy steel or the like, the wear resistance is not sufficient, and if it exceeds 0.95, the Ti content is relatively reduced, leading to embrittlement. , Chipping resistance is reduced. Therefore, the sum α _avg + β _avg of the average content ratio α _{avg of} Al and the average content ratio β _{avg of} Me was determined as 0.605 ≦ α _avg + β _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 the Si component or the B component is used so that β _avg is 0.005 or more as Me, the hardness of the composite nitride or composite carbonitride layer is improved, so that the wear resistance is improved. The Zr component has the effect of strengthening the grain boundaries, and the V component improves toughness, so that the chipping resistance is further improved, and the Cr component improves oxidation resistance. The tool life is expected to be even longer. However, in any component, when the average content ratio β _avg exceeds 0.10, the average content ratio of the Al component and the Ti component is relatively decreased, so that the wear resistance or chipping resistance tends to decrease. Therefore, it must be avoided that the average content ratio of β _avg exceeds 0.10.
Further, when the average content ratio (atomic ratio) γ _avg of C contained in the composite nitride or composite carbonitride layer is a small amount in the range of 0 ≦ γ _avg ≦ 0.005, the composite nitride or composite carbonitride The adhesion between the material layer and the tool base or the lower layer is improved and the lubricity is improved to reduce the impact during cutting. As a result, the fracture resistance and resistance of the composite nitride or composite carbonitride layer are reduced. Chipping property is improved. On the other hand, if the average content ratio γ _{avg of} C deviates from the range of 0 ≦ γ _avg ≦ 0.005, the toughness of the composite nitride or composite carbonitride layer decreases, so the chipping resistance and chipping resistance decrease on the contrary. Therefore, it is not preferable. Therefore, the average content ratio γ _avg of C was determined as 0 ≦ γ _avg ≦ 0.005.
(3) About the composite nitride or composite carbonitride of Cr and Al When represented by the composition formula: (Cr _1-p Al _p ) (C _q N _1-q ), it occupies the total amount of Cr and Al in Al The average content ratio p _avg and the average content ratio q _avg in the total amount of C and N in C (wherein p _avg and q _avg are atomic ratios) are 0.70 ≦ p _avg ≦ 0.95, respectively. It is preferable to control so as to satisfy 0 ≦ q _avg ≦ 0.005.
The reason for this is that when the average content ratio p _avg of Al is less than 0.70, the composite nitride or composite carbonitride layer of Cr and Al is inferior in high temperature hardness and inferior in oxidation resistance. When subjected to high-speed intermittent cutting such as, wear resistance is not sufficient. On the other hand, when the average content ratio p _{avg of} Al exceeds 0.95, the content ratio of Cr is relatively decreased, so that embrittlement is caused and chipping resistance is deteriorated. Therefore, the average Al content ratio p _avg was determined as 0.70 ≦ _pavg ≦ 0.95.
Further, when the content ratio (atom ratio) q _avg of the C component contained in the composite nitride or the composite carbonitride layer is a minute amount in the range of 0 ≦ q _avg ≦ 0.005, the composite nitride or the composite carbonitride The adhesion between the material layer and the tool base or the lower layer is improved and the lubricity is improved to reduce the impact during cutting. As a result, the fracture resistance and resistance of the composite nitride or composite carbonitride layer are reduced. Chipping property is improved. On the other hand, if the average content ratio q _{avg of the} component C deviates from the range of 0 ≦ q _avg ≦ 0.005, the toughness of the composite nitride or composite carbonitride layer is lowered, so that the fracture resistance and chipping resistance are reversed. Since it falls, it is not preferable. Therefore, the average content ratio q _avg of the C component is set to 0 ≦ q _avg ≦ 0.005.

Average orientation difference (GOS value) in individual crystal grains of the crystal grains having a cubic structure constituting the composite nitride or composite carbonitride layer:
First, in the present invention, an electron beam backscattering diffractometer is used to analyze at an interval of 0.1 μm from the longitudinal cross-sectional direction, and as shown in FIG. If there is a misorientation, this is defined as the grain boundary B. The longitudinal section direction means a direction perpendicular to the longitudinal section. A longitudinal section means a section of a tool perpendicular to the tool base surface. A region surrounded by the grain boundary B is defined as one crystal grain. However, a single pixel P having an orientation difference of 5 degrees or more with all adjacent pixels P is not a crystal grain, and a case where two or more pixels are connected is handled as a crystal grain.
Then, an orientation difference is calculated between a certain pixel P in the crystal grain and all other pixels in the same crystal grain, and an average of these is defined as a GOS (Grain Orientation Spread) value. A schematic diagram is shown in FIG. The GOS value is described in, for example, the document “The Journal of the Japan Society of Mechanical Engineers (A) 71: 712 (2005-12) Paper No. 05-0367 1722-1728”. In the present invention, the “average orientation difference in crystal grains” means this GOS value. When the GOS value is expressed by an equation, the number of pixels in the same crystal grain is n, the numbers assigned to different pixels in the crystal grain are i and j (where 1 ≦ i and j ≦ n), and the pixel i And the crystal orientation difference obtained from the crystal orientation at pixel j as α _{ij (i ≠ j)} can be written by the following equation.

The average orientation difference and GOS value within a crystal grain are numerical values obtained by calculating the orientation difference between a certain pixel P in the crystal grain and all other pixels in the same crystal grain and averaging the values. In other words, a large numerical value is obtained when there are many continuous orientation changes in the crystal grains.

Using an electron backscatter diffractometer,
(1) An analysis is made at intervals of 0.1 μm from the longitudinal cross-sectional direction of a composite nitride or composite carbonitride layer of Ti and Al, or a composite nitride or composite carbonitride layer of Cr and Al. The measurement from the longitudinal cross-sectional direction within the measurement range of the film thickness is carried out with 5 fields of view,
(2) With respect to the surface polished surface from the direction perpendicular to the surface of the composite nitride or composite carbonitride layer of Ti, Al, and Me, the measurement range of 25 × 25 μm is performed at 0.1 μm intervals and 5 fields of view,
The total number of pixels belonging to the crystal grains having a cubic structure constituting the composite nitride or composite carbonitride layer is obtained, the average orientation difference in the crystal grains is divided at intervals of 1 degree, and the crystal grains are within the range of the values. A histogram showing the area ratio of the average orientation difference in the crystal grain can be created by counting the pixel P of the crystal grain including the inner average orientation difference and dividing by the total number of pixels. As a result, the crystal orientation within the crystal grains varies, and when the histogram is obtained, the crystal grains showing an average orientation difference within the crystal grains of 2 degrees or more are compared with the composite nitride or composite carbonitride layer of Al and Ti. The area ratio was found to be 20% or more (for example, see FIG. 3 measured according to the above (1)).
Thus, the surface-coated cutting tool of the present invention has a composite nitride or composite carbonitride layer of Al and Ti, a composite nitride or composite carbonitride of Ti, Al and Me, a composite nitride or composite of Al and Cr. This is because the crystal grains constituting the carbonitride have a large variation in crystal orientation within the crystal grains compared to the crystal grains constituting the conventional TiAlN layer and CrAlN layer. Contributes to improved hardness and toughness.
The area ratio of crystal grains having an average orientation difference within the crystal grains of 2 degrees or more with respect to the area of the preferred composite nitride or composite carbonitride layer is 30 to 60%. The area ratio of crystal grains having an average orientation difference within the crystal grains of 2 degrees or more with respect to the area of the more preferable composite nitride or composite carbonitride layer is 35 to 55%. Further, when the composite nitride or composite carbonitride layer of Al and Ti, the composite nitride or composite carbonitride of Al and Cr, the crystal with respect to the area of the composite nitride or composite carbonitride layer is more preferable. The area ratio of crystal grains having an in-grain average orientation difference of 2 degrees or more is 40 to 50%.

Crystal orientation in the region on the tool base side and the region on the surface side when the composite nitride or composite carbonitride layer is divided into two equal parts in the layer thickness direction:
The crystal grains constituting the composite nitride or composite carbonitride layer are such that the surface side is directed to the normal direction of the tool base surface, that is, the {110} plane, rather than the tool base surface (interface) side. An effect peculiar to the present invention that the chipping resistance is improved while maintaining the wear resistance is exhibited.
However, if the increase rate of the {110} plane orientation degree on the surface side relative to the tool base side is less than 10%, the increase rate of the {110} plane orientation degree is small, and the wear resistance expected in the present invention is maintained. The effect of improving the chipping resistance is not sufficiently exhibited. On the other hand, if it exceeds 30%, the epitaxial growth of crystals is hindered due to a rapid change in orientation, and the toughness is lowered. Further, when the {110} plane orientation degree on the tool base side is less than 10%, the increase rate of the {110} plane orientation degree on the surface side becomes 30% or more, and when the {110} plane orientation degree on the tool base side exceeds 40%. It was found that the rate of increase in the degree of orientation of the {110} plane on the surface side was less than 10%. Therefore, the tool base side obtained by dividing the inclination angle formed by the normal of the {110} plane, which is a crystal plane with respect to the normal direction of the surface of the tool base of the crystal grains, into two equal parts in the layer thickness direction of the composite nitride or composite carbonitride layer The measured inclination angle is in the range of 0 to 45 degrees with respect to the normal direction among the measured inclination angles, and is divided into pitches of 0.25 degrees. When the frequencies existing in each section are tabulated, a) In the region on the tool base side, the total number of frequencies existing in the range of 0 to 12 degrees represents the ratio to the total frequency in the inclination angle frequency distribution. Assuming M _deg , M _deg is 10 to 40%, and b) In the region on the surface side, the highest peak exists in the inclination angle section within the range of 0 to 12 degrees, and within the range of 0 to 12 degrees. The sum of the frequencies present is the total frequency in the tilt angle distribution When a slip and N _{_deg,} N _deg is defined to be _{_{M deg + 10 ~ M deg +}} 30%.

Area ratio of composite nitride or composite carbonitride layer:
A composite nitride or composite carbonitride layer of Ti and Al, Ti and Al and Me, Cr and Al is excellent by including at least a composite nitride or composite carbonitride phase having a NaCl type face-centered cubic structure. Abrasion resistance is exhibited, and particularly excellent abrasion resistance is exhibited when the area ratio exceeds 70%.

Average grain width W and average aspect ratio A of individual grains having a cubic structure in the composite nitride or composite carbonitride layer:
Average grain width W of individual grains having a cubic structure in a composite nitride or composite carbonitride layer of Ti and Al, Ti and Al and Me, Cr and Al, and an average aspect ratio A By configuring so as to have a columnar structure with 2 to 10, the above-described effect of improving toughness and wear resistance can be further exhibited.
That is, the average grain width W is set to 0.1 to 2 μm, if it is less than 0.1 μm, the atoms belonging to the TiAlCN grain boundary, TiAlMeCN grain boundary, and CrAlCN grain boundary occupied by the atoms exposed on the surface of the coating layer When the ratio is relatively large, the reactivity with the work material is increased, and as a result, the wear resistance cannot be sufficiently exhibited, and when it exceeds 2 μm, the TiAlCN grain boundary in the entire coating layer When the ratio of the atoms belonging to the TiAlMeCN grain boundary and the CrAlCN crystal grain boundary becomes relatively small, the toughness is lowered and the chipping resistance cannot be sufficiently exhibited. Therefore, the average particle width W is preferably 0.1 to 2 μm.
In addition, when the average aspect ratio A is less than 2, since the columnar structure is not sufficient, the equiaxed crystal having a small aspect ratio is dropped, and as a result, sufficient wear resistance cannot be exhibited. On the other hand, if the average aspect ratio A exceeds 10, the strength of the crystal grains themselves cannot be maintained, and the chipping resistance is lowered. Therefore, the average aspect ratio A is preferably 2-10.
In the present invention, the average aspect ratio A means the surface of the tool base when the longitudinal section of the hard coating layer is observed in a range of 100 μm in width and including the entire hard coating layer using a scanning electron microscope. The particle width w in the direction parallel to the substrate surface and the particle length l in the direction perpendicular to the substrate surface are measured, and the aspect ratio a (= l / w) of each crystal grain is measured. While calculating, the average value of the aspect ratio a calculated | required about each crystal grain was calculated as the average aspect ratio A, and the average value of the particle width w calculated | required about each crystal grain was calculated as the average particle width W.

Lower layer and upper layer:
Further, the composite nitride or composite carbonitride layer possessed by the surface-coated cutting tool of Ti and Al, Ti and Al and Me, and Cr and Al of the present invention alone has a sufficient effect, but a Ti carbide layer, A lower layer having a total average layer thickness of 0.1 to 20 μm is provided. And / or when an upper layer including an aluminum oxide layer having an average layer thickness of 1 to 25 μm is provided, combined with the effect of these layers, creates better characteristics. Can do. When providing a lower layer made of one or two or more Ti compound layers of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer and carbonitride oxide layer, the total average layer of the lower layer If the thickness is less than 0.1 μm, the effect of the lower layer is not sufficiently achieved. On the other hand, if it exceeds 20 μm, the crystal grains are likely to be coarsened and chipping is likely to occur. Moreover, if the total average layer thickness of the upper layer including the aluminum oxide layer is less than 1 μm, the effect of the upper layer is not sufficiently achieved. .
FIG. 2 schematically shows a cross section of a Ti / Al composite nitride or composite carbonitride layer constituting the hard coating layer of Ti and Al, Ti and Al and Me, and Cr and Al of the present invention. Shown in

Next, the coated tool of the present invention will be specifically described with reference to examples.
As an example, a coated tool using a WC-based cemented carbide or TiCN-based cermet as a tool base will be described, but the same applies when a cubic boron nitride-based ultra-high pressure sintered body is used as the tool base.

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 A to J shown in Tables 4 and 5, that is, a gas group A composed of NH ₃ , N ₂ and H ₂ , TiCl ₄ , Al (CH ₃ ) ₃ , AlCl ₃ , N ₂ , As a method for supplying the gas group B composed of H ₂ and the respective gases, the reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) is used, and NH ₃ : 3.5-4. 0%, N ₂ : 1.0 to 2.0%, H ₂ : 55 to 60%, gas group B as AlCl ₃ : 0.6 to 0.9%, TiCl ₄ : 0.2 to 0.3% Al (CH ₃ ) ₃ : 0 to 0.5%, N ₂ : 12.5 to 15.0%, H ₂ : remaining, reaction atmosphere pressure: 4.5 to 5.0 kPa, reaction atmosphere temperature: 700 to 900 ° C, supply cycle 1 to 5 seconds, gas supply time per cycle 0.15 to 0.25 seconds, gas group A and gas A crystal grain having a cubic structure in which the thermal CVD method is carried out for a predetermined time with a phase difference of 0.10 to 0.20 seconds for the supply of group B, and the average orientation difference in the crystal grains shown in Table 7 is 2 degrees or more Is formed by forming a hard coating layer composed of a (Ti _1-x Al _x ) (C _y N _1-y ) layer having the area ratio shown in Table 7 and having the target layer thickness shown in Table 7. Coated tools 1-15 were produced.
For the coated tools 6 to 13 of the present invention, the lower layer shown in Table 6 and / or the upper layer shown in Table 7 were formed under the formation conditions shown in Table 3.

For comparison purposes, at least the surfaces of the tool bases A to D were subjected to the conditions shown in Tables 4 and 5 and the target layer thickness (μm) shown in Table 8, at least as in the present coated tools 1 to 15. A hard coating layer including a composite nitride or composite carbonitride layer of Ti and Al was deposited. At this time, a comparison is made by forming a hard coating layer so that the reaction gas composition on the surface of the tool base does not change with time during the process of forming the (Ti _1-x Al _x ) (C _y N _1-y ) layer. Coated tools 1-13 were produced.
Similar to the coated tools 6 to 13 of the present invention, the comparative coated tools 6 to 13 are formed with the lower layer shown in Table 6 and / or the upper layer shown in Table 8 under the forming conditions shown in Table 3. did.

For reference, the (Ti _1-x Al _x ) (C _y N _1-y ) layer of the reference example is formed on the surfaces of the tool base B and the tool base C by arc ion plating using a conventional physical vapor deposition apparatus. The reference coated tools 14 and 15 shown in Table 8 were produced by vapor-depositing with a target layer thickness.
The arc ion plating conditions used for the vapor deposition in the reference example are as follows.
(A) The tool bases B and C are ultrasonically washed in acetone and dried, and the outer periphery is positioned at a predetermined distance in the radial direction from the central axis on the rotary table in the arc ion plating apparatus. In addition, an Al—Ti alloy having a predetermined composition is disposed as a cathode electrode (evaporation source),
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 10 ⁻² Pa or less, the inside of the apparatus is heated to 500 ° C. with a heater, and then the tool base that rotates while rotating on the rotary table is set to −1000 V. A DC bias voltage is applied and a current of 200 A is passed between a cathode electrode and an anode electrode made of an Al—Ti alloy to generate an arc discharge, and Al and Ti ions are generated in the apparatus. Clean the surface with bombard,
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 4 Pa, a DC bias voltage of −50 V is applied to the tool base that rotates while rotating on the rotary table, and An arc discharge was generated by passing a current of 120 A between the cathode electrode (evaporation source) made of the Al—Ti alloy and the anode electrode.

In addition, the cross sections in the direction perpendicular to the tool base of the constituent layers of the coated tools 1 to 15 of the present invention, the comparative coated tools 1 to 13 and the reference coated tools 14 and 15 are measured using a scanning electron microscope (5000 magnifications). When the average layer thickness was obtained by measuring and averaging the five layer thicknesses in the observation field, all showed the same average layer thickness as the target layer thicknesses shown in Tables 6 to 8. .

The average Al content x _avg of the composite nitride or composite carbonitride layer was measured using an electron beam microanalyzer (Electron-Probe-Micro-Analyzer: EPMA) in a sample whose surface was polished. Irradiation was performed from the sample surface side, and an average Al content ratio x _avg was obtained from an average of 10 points of the analysis results of the obtained characteristic X-rays. The average C content y _avg was determined by secondary ion mass spectrometry (Secondary-Ion-Mass- Spectroscopy: SIMS). 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 content ratio y _avg of C indicates an average value in the depth direction of the composite nitride or composite carbonitride layer of Ti and Al. 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 composite carbonitride layer when the supply amount of Al (CH ₃ ) ₃ is 0 is determined as the inevitable C content ratio. , The inevitable C content is subtracted from the C component content (atomic ratio) contained in the composite nitride or composite carbonitride layer obtained when Al (CH ₃ ) ₃ is intentionally supplied. The value was determined as _yavg .

Further, the crystal orientation of each crystal grain having a cubic structure constituting the composite nitride or composite carbonitride layer of Ti and Al is analyzed from the longitudinal cross-sectional direction using an electron beam backscatter diffraction apparatus, and adjacent pixels are analyzed. If there is a misorientation of 5 degrees or more between them, this is the grain boundary, and the region surrounded by the grain boundary is one crystal grain. One pixel in the crystal grain and all other pixels in the same crystal grain The difference in orientation within the grain is calculated between 0 degree and less than 1 degree, 1 degree and less than 2 degree, 2 degree and less than 3 degree, 3 degree and less than 4 degree, and so on. The range of 10 degrees was divided and mapped every 1 degree. From the mapping chart, the area ratio of the crystal grains having an average orientation difference in the crystal grains of 2 degrees or more to the entire composite nitride or composite carbonitride layer of Ti and Al was obtained.
The results are shown in Table 7 and Table 8.
FIG. 3 shows an example of a histogram of the average orientation difference in crystal grains (that is, GOS value) measured for the coated tool 24 of the present invention, and FIG. 4 shows the average orientation difference in crystal grains measured for the comparative coated tool 19. An example of the histogram is shown.

In addition, regarding the inclination angle number distribution of the hard coating layer, the column of the field emission scanning electron microscope with the cross section of the hard coating layer made of a composite carbonitride layer of Ti and Al having a cubic structure as a polished surface An electron beam with an acceleration voltage of 10 kV at an incident angle of 70 degrees is divided into a region on the surface (interface) side of the tool base and the region on the surface side, which is divided into two in the layer thickness direction. With an irradiation current of 1 nA, within the measurement range of the tool base side area and the surface side area in the direction perpendicular to the tool base, the width of 10 μm in the horizontal direction with respect to the tool base is 0.1 μm / step for five fields of view. Are irradiated with individual crystal grains having a cubic crystal lattice existing within the measurement range, and using the electron backscatter diffraction image apparatus, the normal of the tool base surface (perpendicular to the tool base surface on the cross-section polished surface) The crystal grains) The inclination angle formed by the normal of the {110} plane, which is the crystal plane, is measured. Based on the measurement result, the measurement inclination angle within the range of 0 to 45 degrees is set to 0.25 degrees among the measurement inclination angles. The ratio of the frequencies existing in the range of 0 to 12 degrees was obtained by summing up the frequencies existing in each section. The results are shown in Table 7 and Table 8.
FIG. 5 shows an example of the distribution of the number of inclination angles measured for the region on the tool base side of the hard coating layer composed of the composite carbonitride layer of Ti and Al of the coated tool of the present invention, and FIG. An example of the inclination angle number distribution measured about the area | region of the surface side of the hard coating layer which consists of a composite carbonitride layer of Ti and Al of a coating tool is shown.
Furthermore, analysis was performed at intervals of 0.1 μm from the longitudinal cross-section direction using an electron beam backscattering diffractometer, the width was 10 μm, and the vertical measurement within the measurement range of the film thickness was performed in five fields of view. The total number of pixels belonging to crystal grains having a cubic structure constituting the nitride or composite carbonitride layer is obtained, and the composite nitridation is performed according to the ratio to the total number of measured pixels in the measurement with respect to the hard coating layer in the five fields of view. The area ratio of crystal grains having a cubic structure constituting the product or composite carbonitride layer was determined.

Next, the coated tools 1 to 15 according to the present invention, the comparative coated tools 1 to 13 and the reference coated tool are used in the state where each of the various coated tools is clamped to the tool steel cutter tip portion having a cutter diameter of 125 mm by a fixing jig. About 14 and 15, the dry type high-speed face milling which is a kind of the high-speed intermittent cutting of the alloy steel and the center cut cutting test shown below were carried out, and the flank wear width of the cutting edge was measured. The results are shown in Table 9.

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: 917 min ⁻¹
Cutting speed: 360 m / min,
Cutting depth: 2.0 mm,
Single blade feed rate: 0.2 mm / tooth,
Cutting time: 8 minutes

As raw material powders, WC powder, TiC powder, ZrC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder and Co powder all 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, on the surfaces of these tool bases α to γ and tool base δ, a chemical vapor deposition apparatus is used, and at least (Ti _1-x Al) under the conditions shown in Tables 4 and 5 by the same method as in Example 1. _The coated tools 16 to 30 according to the present invention shown in Table 13 were manufactured by vapor-depositing a hard coating layer containing _x ) (C _y N _1-y ) layer at a target layer thickness.
For the coated tools 19 to 28 of the present invention, the lower layer shown in Table 12 and / or the upper layer shown in Table 13 were formed under the formation conditions shown in Table 3.

For comparison purposes, the present invention is also applied to the surfaces of the tool bases α to γ and the tool base δ by using an ordinary chemical vapor deposition apparatus under the conditions shown in Tables 4 and 5 and the target layer thicknesses shown in Table 14. Comparative coating tools 16 to 28 shown in Table 14 were manufactured by vapor-depositing a hard coating layer in the same manner as the coating tool.
As with the coated tools 19 to 28 of the present invention, the comparative coated tools 19 to 28 are formed with the lower layer shown in Table 12 and / or the upper layer shown in Table 14 under the forming conditions shown in Table 3. did.

For reference, the (Ti _1-x Al _x ) (C _y N _1-y ) layer of the reference example is formed on the surfaces of the tool base β and the tool base γ by arc ion plating using a conventional physical vapor deposition apparatus. The reference coating tools 29 and 30 shown in Table 14 were manufactured by vapor-depositing with a target layer thickness.
In addition, the conditions similar to the conditions shown in Example 1 were used for the conditions of arc ion plating.

Further, the cross-sections of the constituent layers of the inventive coated tools 16 to 30, the comparative coated tools 16 to 28 and the reference coated tools 29 and 30 were measured using a scanning electron microscope (magnification 5000 times), and 5 in the observation field of view. When the average layer thickness was obtained by measuring the layer thickness at the points, the average layer thickness was substantially the same as the target layer thickness shown in Tables 12 to 14.

Furthermore, the crystal orientation of each crystal grain having a cubic structure constituting a composite nitride or composite carbonitride layer of Ti and Al is analyzed from the longitudinal cross-sectional direction using an electron beam backscatter diffraction apparatus, The difference in direction is 0 degree or more, less than 1 degree, 1 degree or more, less than 2 degree, 2 degree or more, less than 3 degree, 3 degree or more, less than 4 degree, and so on. did. From the mapping diagram, the area ratio of the crystal grains having an average orientation difference within the grain and an orientation difference within the grain of 2 degrees or more to the entire composite nitride or composite carbonitride layer of Ti and Al was obtained. The results are shown in Table 13 and Table 14.

In addition, regarding the inclination angle number distribution of the hard coating layer, the column of the field emission scanning electron microscope with the cross section of the hard coating layer made of a composite carbonitride layer of Ti and Al having a cubic structure as a polished surface An electron beam with an acceleration voltage of 10 kV at an incident angle of 70 degrees is divided into a region on the surface (interface) side of the tool base and the region on the surface side, which is divided into two in the layer thickness direction. Is irradiated to each of the crystal grains having a cubic crystal lattice existing within the measurement range of the region on the tool base side and the region on the surface side with an irradiation current of 1 nA, and using an electron beam backscatter diffraction image apparatus, The crystal of the crystal grains with respect to the normal of the tool base surface (direction perpendicular to the tool base surface on the cross-section polished surface) at a spacing of 0.1 μm / step with a width of 10 μm and five fields of view in the horizontal direction. The slope formed by the normal of the {110} plane The angle is measured, and based on the measurement result, the measurement inclination angle within the range of 0 to 45 degrees is divided into the 0.25 degree pitches among the measurement inclination angles, and exists in each division. By counting the frequencies, the ratio of the frequencies existing in the range of 0 to 12 degrees was obtained. The results are shown in Table 13 and Table 14.

Next, with the various coated tools all screwed to the tip of the tool steel tool with a fixing jig, the coated tools 16 to 30 of the present invention, the comparative coated tools 16 to 28 and the reference coated tool 29, For 30, a dry high-speed intermittent cutting test of carbon steel and a wet high-speed intermittent cutting test of ductile cast iron shown below were carried out, and the flank wear width of the cutting edge was measured.
Cutting condition 1:
Work material: JIS · S45C lengthwise equal 4 round grooved round bars,
Cutting speed: 350 m / min,
Incision: 1.5mm,
Feed: 0.25mm / 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: 300 m / min,
Incision: 1.5mm,
Feed: 0.25mm / rev,
Cutting time: 5 minutes
(Normal cutting speed is 200 m / min),
Table 15 shows the results of the cutting test.

From the results shown in Table 9 and Table 15, the coated tool of the present invention is a crystal grain having a cubic structure constituting a composite nitride or composite carbonitride layer of Al and Ti constituting the hard coating layer. In addition to the presence of a predetermined in-grain average orientation difference, the inclination angle formed by the normal line of the {110} plane in the region on the tool base side and the surface side of the crystal grain has a predetermined inclination angle number distribution. The distortion of the crystal grains improves the hardness and improves the 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 crystal grains having a cubic structure constituting the composite nitride of Al and Ti or the composite carbonitride layer constituting the hard coating layer, there is no predetermined intra-grain average orientation difference. The comparative coated tools 1 to 13, 16 to 28 in which the inclination angle formed by the normal of the {110} plane in the region on the tool base side and the surface side of the crystal grains does not have a predetermined inclination angle number distribution, and The reference coated

tools

14, 15, 29, and 30 are accompanied by high heat generation, and when used for high-speed intermittent cutting where intermittent and impactful high loads act on the cutting edge, shorting occurs due to chipping, chipping, etc. It is clear that the life is reached in time.

A chemical vapor deposition apparatus is used on the surfaces of the tool bases A to D, and the formation conditions shown in Tables 17 and 18, that is, a gas group A composed of NH ₃ , N _2, and H ₂ , TiCl ₄ , Al (CH ₃ ) ₃ , AlCl ₃ , MeCl _n (however, any one of SiCl ₄ , ZrCl ₄ , BCl ₃ , VCl ₄ , CrCl ₂ ), a gas group B composed of N ₂ , H ₂ , and a method for supplying each gas The reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) is NH ₃ : 3.5 to 4.0% as the gas group A, N ₂ : 1.0 to 2.0%, H ₂ : 55 to 60%, gas group B as 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, SiCl 4, ZrCl 4, BCl}} 3 Any of _{_{_{VCl 4, CrCl 2): 0.1}}} ~ 0.2%, N 2: 12.5 ~ 15.0%, H 2: remainder, reaction atmosphere pressure: 4.5 ~ 5.0 kPa, Reaction atmosphere temperature: 700 to 900 ° C., supply cycle 1 to 5 seconds, gas supply time per cycle 0.15 to 0.25 seconds, supply gas phase difference A and gas group B phase difference 0.10 to 0. 20 seconds, a thermal CVD method is performed for a predetermined time, and there are crystal grains having a cubic structure in which the average orientation difference in the crystal grains shown in Table 20 is 2 degrees or more. The coated tools 31 to 45 of the present invention were manufactured by forming a hard coating layer composed of a (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) layer having a target layer thickness shown in FIG.
For the coated tools 36 to 43 of the present invention, the lower layer shown in Table 19 and / or the upper layer shown in Table 20 were formed under the formation conditions shown in Table 16.

For comparison purposes, on the surfaces of the tool bases A to D, at least the conditions shown in Tables 17 and 18 and the target layer thickness (μm) shown in Table 21 are the same as those of the present coated tools 31 to 45. A hard coating layer including a composite nitride or composite carbonitride layer of Ti and Al was deposited. At this time, the hard coating layer 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-α-β Al _α Me _β ) (C _γ N _1-γ ) layer. Thus, comparative coated tools 31 to 45 were produced.
As with the coated tools 36 to 43 of the present invention, the lower layer shown in Table 19 and / or the upper layer shown in Table 21 are formed for the comparative coated tools 36 to 43 under the forming conditions shown in Table 16. did.

Further, the cross-sections of the constituent layers of the inventive coated tools 31 to 45 and comparative coated tools 31 to 45 in the direction perpendicular to the tool substrate were measured using a scanning electron microscope (with a magnification of 5000 times), and within the observation field of view. When the average layer thickness was obtained by measuring and averaging the five layer thicknesses, all showed an average layer thickness substantially the same as the target layer thickness shown in Table 19 to Table 21.

Moreover, about the average Al content rate and average Me content rate of a composite nitride or a composite carbonitride layer, in the sample which polished the surface using the electron beam microanalyzer (EPMA), an electron beam was irradiated from the sample surface side. The average Al content rate α _{avg of} Al and the average content rate β _avg of Me were obtained from the average of 10 points of the analysis results of the obtained characteristic X-rays. About average C content rate (gamma) _avg, it calculated _| required by secondary ion mass spectrometry (SIMS). 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 γ _avg represents an average value in the depth direction of the composite nitride or composite carbonitride layer 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 composite carbonitride layer when the supply amount of Al (CH ₃ ) ₃ is 0 is determined as the inevitable C content ratio. , The inevitable C content is subtracted from the C component content (atomic ratio) contained in the composite nitride or composite carbonitride layer obtained when Al (CH ₃ ) ₃ is intentionally supplied. The value was determined as γ _avg . The results are shown in Table 20 and Table 21.

Furthermore, the crystal orientation of each crystal grain having a cubic structure constituting the composite nitride or composite carbonitride layer of Ti, Al, and Me is analyzed from the longitudinal cross-section direction using an electron beam backscatter diffraction apparatus, If there is an orientation difference of 5 degrees or more between the pixels to be used as a grain boundary, and the region surrounded by the grain boundary is a single crystal grain, one pixel in the crystal grain and all the other in the same crystal grain The crystal grain orientation difference is calculated between the pixels, and the crystal grain orientation difference is 0 degree or more and less than 1 degree, 1 degree or more and less than 2 degree, 2 degree or more and less than 3 degree, 3 degree or more and less than 4 degree, and so on. The range of 0 to 10 degrees was divided and mapped every 1 degree. From the mapping diagram, the area ratio of the crystal grains having an average orientation difference within the crystal grains of 2 degrees or more to the entire composite nitride or composite carbonitride layer of Ti, Al, and Me was obtained. The results are shown in Table 20 and Table 21.
FIG. 7 shows an example of a histogram of the average orientation difference in crystal grains measured for the coated tool of the present invention, and FIG. 8 shows an example of a histogram of the average orientation difference in crystal grains measured for the comparative coated tool.

In addition, regarding the distribution of the inclination angle number of the hard coating layer, a field emission scanning electron microscope with a cross section of the hard coating layer composed of a composite carbonitride layer of Ti, Al, and Me having a cubic structure is used as a polished surface. Acceleration voltage of 10 kV at an incident angle of 70 degrees is set in a lens barrel and analyzed separately for the tool base surface (tool base) side region and the surface side region obtained by dividing the polishing surface into two equal parts in the layer thickness direction. With an irradiation current of 1 nA, with respect to the tool substrate in the direction perpendicular to the tool substrate, within the measurement range of the region on the interface side and the region on the surface side, the width of the tool substrate in the horizontal direction is 10 μm and 0.1 μm for five fields of view Is irradiated with individual crystal grains having a cubic crystal lattice existing in the measurement range at an interval of / step, and the normal of the tool base surface (the tool base surface on the cross-section polished surface) is obtained using an electron beam backscatter diffraction image apparatus. Direction). The tilt angle formed by the normal of the {110} plane, which is the crystal plane of the crystal grain, is measured, and based on the measurement result, the measured tilt angle within the range of 0 to 45 degrees out of the measured tilt angles is 0. .Division for each pitch of 25 degrees, and by counting the frequencies existing in each division, the angle range where the highest peak exists in the slope angle division in the surface side region and within the range of 0-12 degrees The ratios M _deg and N _deg of the existing frequencies were obtained. The results are shown in Table 20 and Table 21.
FIG. 9 shows an example of an inclination angle number distribution measured for a region on the tool base side of a hard coating layer composed of a composite nitride or composite carbonitride layer of Ti, Al, and Me of the coated tool of the present invention. 10 shows an example of an inclination angle number distribution measured for a region on the surface side of a hard coating layer composed of a composite nitride or composite carbonitride layer of Ti, Al, and Me of the coated tool of the present invention.
Furthermore, analysis was performed at intervals of 0.1 μm from the longitudinal cross-section direction using an electron beam backscattering diffractometer, the width was 10 μm, and the vertical measurement within the measurement range of the film thickness was performed in five fields of view. The total number of pixels belonging to crystal grains having a cubic structure constituting the nitride or composite carbonitride layer is obtained, and the composite nitridation is performed according to the ratio to the total number of measured pixels in the measurement with respect to the hard coating layer in the five fields of view. The area ratio of crystal grains having a cubic structure constituting the product or composite carbonitride layer was determined. The results are shown in Table 20 and Table 21.

Further, for the coated tools 31 to 45 of the present invention and the comparative coated tools 31 to 45, using a scanning electron microscope (magnification 5000 times or 20000 times) from the cross-sectional direction perpendicular to the tool substrate, the tool substrate surface and the horizontal direction to configure the Ti composite nitride of Al and Me or composite carbonitride layer present within the range of length _{10μm (Ti 1-α-β} Al α Me β) (C γ N 1-γ) layer of Each crystal grain is observed from the cross section side of the film perpendicular to the surface of the tool substrate, and the particle width w in the direction parallel to the substrate surface and the particle length l in the direction perpendicular to the substrate surface are measured. The ratio 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 The average particle width It was calculated as. The results are shown in Table 20 and Table 21.

Next, the coated tools 31 to 45 of the present invention and the comparative coated tools 31 to 45 in the state where each of the various coated tools is clamped to the tip of a cutter made of tool steel having a cutter diameter of 125 mm by a fixing jig will be described below. The dry 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. The results are shown in Table 22.

Tool substrate: Tungsten carbide-based cemented carbide, titanium carbonitride-based cermet,
Cutting test: dry high-speed face milling, center cutting,
Work material: Block material of JIS / S55C width 100mm, length 400mm,
Rotational speed: 765 min ⁻¹
Cutting speed: 300 m / min,
Cutting depth: 2.0 mm,
Single blade feed amount: 0.20 mm / tooth,
Cutting time: 8 minutes

On the surfaces of the tool bases α to γ and the tool base δ, a chemical vapor deposition apparatus is used, and at least (Ti _1-α-β Al _α Me _β ) The coated tools 46 to 60 of the present invention shown in Table 24 were manufactured by vapor-depositing a hard coating layer including a (C _γ N _1-γ ) layer at a target layer thickness.
For the coated tools 49 to 58 of the present invention, the lower layer shown in Table 23 and / or the upper layer shown in Table 24 were formed under the formation conditions shown in Table 16.

Further, for comparison purposes, the coated tool of the present invention was similarly used on the surfaces of the tool bases α to γ and the tool base δ using the chemical vapor deposition apparatus under the conditions shown in Tables 17 and 18 and the target layer thicknesses shown in Table 25. Comparative coating tools 46 to 60 shown in Table 25 were manufactured by vapor-depositing a hard coating layer in the same manner as described above.
As with the coated tools 49 to 58 of the present invention, the lower layer shown in Table 23 and / or the upper layer shown in Table 25 are formed for the comparative coated tools 49 to 58 under the forming conditions shown in Table 16. did.

Further, the cross-section of each constituent layer of the coated tool 46 to 60 of the present invention and the comparative coated tool 46 to 60 is measured using a scanning electron microscope (magnification 5000 times), and the layer thickness at five points in the observation field is measured. When the average layer thickness was obtained on average, all showed the average layer thickness substantially the same as the target layer thickness shown in Tables 23 to 25.
For the hard coating layers of the inventive coated tools 46 to 60 and comparative coated tools 46 to 60, the average Al content ratio α _avg , the average Me content ratio β _avg , average C content ratio γ _avg , inclination angle number distribution M _deg on the tool base side, inclination angle number distribution N _{deg on} the surface side, range of angles where the highest peak exists in the inclination angle section in the region on the surface side, crystal grains The average grain width W, the average aspect ratio A, and the area ratio of the cubic crystal phase in the crystal grains were determined. The results are shown in Table 24 and Table 25.

Furthermore, the crystal orientation of each crystal grain having a cubic structure constituting the composite nitride or composite carbonitride layer of Ti, Al, and Me is analyzed from the longitudinal cross-sectional direction using an electron beam backscattering diffractometer. Intragranular orientation difference is 0 degree or more, less than 1 degree, 1 degree or more, less than 2 degree, 2 degree or more, less than 3 degree, 3 degree or more, less than 4 degree, and so on. , Mapped. From the mapping diagram, the area ratio of the crystal grains having the average orientation difference in the crystal grains and the orientation difference in the crystal grains of 2 degrees or more to the entire composite nitride or composite carbonitride layer of Ti, Al, and Me was obtained. The results are shown in Table 24 and Table 25.

Next, the coated tools 46 to 60 of the present invention and the comparative coated tools 46 to 60 are shown below 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 for carbon steel and a wet high-speed intermittent cutting test for cast iron were performed, and the flank wear width of the cutting edge was measured for both.
Cutting condition 1:
Work material: JIS / S15C lengthwise equal length 4 vertical grooved round bars,
Cutting speed: 320 m / min,
Cutting depth: 2.0 mm
Feed: 0.25mm / rev,
Cutting time: 5 minutes
(Normal cutting speed is 220 m / min),
Cutting condition 2:
Work material: JIS / FCD450 lengthwise equidistant round bars with 4 vertical grooves,
Cutting speed: 350 m / min,
Incision: 1.5mm,
Feed: 0.25mm / rev,
Cutting time: 5 minutes
(Normal cutting speed is 250 m / min),
Table 26 shows the results of the cutting test.

From the results shown in Tables 22 and 26, the coated tool of the present invention has a crystal structure having a cubic structure constituting a composite nitride or composite carbonitride layer of Al, Ti, and Me constituting the hard coating layer. In the above, there is a predetermined difference in average orientation within crystal grains, and the surface side region has a higher {110} orientation than the tool base side, thereby improving hardness and maintaining high wear resistance while maintaining toughness. And chipping resistance is improved. 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, there is a predetermined intra-grain average orientation difference in the crystal grains having a cubic structure constituting the composite nitride of Al, Ti, and Me or the composite carbonitride layer constituting the hard coating layer. The comparative coated tools 31 to 45 and 46 to 60 which are not used are accompanied by high heat generation, and when used for high-speed intermittent cutting in which intermittent and impact high loads act on the cutting edge, chipping, chipping, etc. occur. It is clear that the lifetime is reached in a short time.

A chemical vapor deposition apparatus is used on the surface of the tool base A to D,
(A) Formation conditions A to J shown in Table 28 and Table 29, that is, a gas group A composed of NH ₃ , N ₂ and H ₂ , CrCl ₃ , AlCl ₃ , Al (CH ₃ ) ₃ , N ₂ , As a method for supplying the gas group B composed of H ₂ and the respective gases, the reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) is used, and NH ₃ : 3.5-4. 0%, N ₂ : 1.0 to 2.0%, H ₂ : 55 to 60%, gas group B as AlCl ₃ : 0.6 to 0.9%, CrCl ₃ : 0.2 to 0.3% Al (CH ₃ ) ₃ : 0 to 0.5%, N ₂ : 12.5 to 15.0%, H ₂ : remaining, reaction atmosphere pressure: 4.5 to 5.0 kPa, reaction atmosphere temperature: 750 to 900 ° C, supply cycle 1 to 5 seconds, gas supply time per cycle 0.15 to 0.25 seconds, gas group A A crystal having a cubic structure in which a thermal CVD method is performed for a predetermined time with a phase difference of 0.10 to 0.20 seconds of supply of gas group B, and an average orientation difference within a crystal grain shown in Table 31 is 2 degrees or more By forming a hard coating layer composed of a (Cr _1-p Al _p ) (C _q N _1-q ) layer having grains having an area ratio shown in Table 31 and having a target layer thickness shown in Table 31 Invention coated tools 61-75 were produced.
For the coated tools 66 to 73 of the present invention, the lower layer shown in Table 30 and / or the upper layer shown in Table 31 were formed under the formation conditions shown in Table 27.

For comparison purposes, on the surfaces of the tool bases A to D, at least as in the present invention coated tools 61 to 75 under the conditions shown in Table 28 and Table 29 and the target layer thickness (μm) shown in Table 32, A hard coating layer including a composite nitride or composite carbonitride layer of Cr and Al was deposited. At this time, a comparison is made by forming a hard coating layer 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 (Cr _1-p Al _p ) (C _q N _1-q ) layer. Coated tools 61-73 were produced.
Similar to the coated tools 66 to 73 of the present invention, the comparative coated tools 66 to 73 are formed with the lower layer shown in Table 30 and / or the upper layer shown in Table 32 under the forming conditions shown in Table 27. did.

For reference, the (Cr _1-p Al _p ) (C _q N _1-q ) layer of the reference example is formed on the surfaces of the tool base B and the tool base C by arc ion plating using a conventional physical vapor deposition apparatus. The reference coated tools 74 and 75 shown in Table 32 were manufactured by vapor-depositing with a target layer thickness.
The arc ion plating conditions used for the vapor deposition in the reference example are as follows.
(A) The tool bases B and C are ultrasonically washed in acetone and dried, and the outer periphery is positioned at a predetermined distance in the radial direction from the central axis on the rotary table in the arc ion plating apparatus. In addition, an Al—Cr alloy having a predetermined composition is arranged as a cathode electrode (evaporation source),
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 10 ⁻² Pa or less, the inside of the apparatus is heated to 500 ° C. with a heater, and then the tool base that rotates while rotating on the rotary table is set to −1000 V. A DC bias voltage is applied and a current of 200 A is passed between a cathode electrode and an anode electrode made of an Al—Cr alloy to generate an arc discharge, thereby generating Al and Cr ions in the apparatus, thereby providing a tool base. Clean the surface with bombard,
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 4 Pa, a DC bias voltage of −50 V is applied to the tool base that rotates while rotating on the rotary table, and An arc discharge was generated by passing a current of 120 A between the cathode electrode (evaporation source) made of the Al—Cr alloy and the anode electrode.

Further, the cross sections in the direction perpendicular to the tool base of each constituent layer of the inventive coated tools 61 to 75, the comparative coated tools 61 to 73 and the reference coated tools 74 and 75 are scanned using a scanning electron microscope (5000 magnifications). Measurements were made and averaged by measuring and averaging the five layer thicknesses within the observation field, and all showed substantially the same average layer thicknesses as the target layer thicknesses shown in Tables 30 to 32. .

Further, the average content ratio p _avg of Al in the composite nitride or the composite carbonitride layer was obtained by irradiating an electron beam from the sample surface side in a sample whose surface was polished using an electron beam microanalyzer (EPMA). The average Al content ratio _pavg was determined from the 10-point average of the obtained characteristic X-ray analysis results. The average content ratio q _avg of C was determined by secondary ion mass spectrometry (SIMS). 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 content ratio q _avg of C indicates an average value in the depth direction of the composite nitride or composite carbonitride layer of Cr and Al. 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 composite carbonitride layer when the supply amount of Al (CH ₃ ) ₃ is 0 is determined as the inevitable C content ratio. , The inevitable C content is subtracted from the C component content (atomic ratio) contained in the composite nitride or composite carbonitride layer obtained when Al (CH ₃ ) ₃ is intentionally supplied. The value was determined as q _avg .

Further, the crystal orientation of each crystal grain having a cubic structure constituting the composite nitride or composite carbonitride layer of Cr and Al is analyzed from the longitudinal cross-sectional direction using an electron beam backscatter diffraction apparatus, and adjacent pixels are analyzed. If there is a misorientation of 5 degrees or more between them, this is the grain boundary, and the region surrounded by the grain boundary is one crystal grain. One pixel in the crystal grain and all other pixels in the same crystal grain The difference in orientation within the grain is calculated between 0 degree and less than 1 degree, 1 degree and less than 2 degree, 2 degree and less than 3 degree, 3 degree and less than 4 degree, and so on. The range of 10 degrees was divided and mapped every 1 degree. From the mapping diagram, the area ratio of the crystal grains having an average orientation difference in the crystal grains of 2 degrees or more to the entire composite nitride or composite carbonitride layer of Cr and Al was obtained.
The results are shown in Table 31 and Table 32.
FIG. 11 shows an example of a histogram of the average orientation difference in crystal grains (that is, the GOS value) measured for the coated tool 19 of the present invention, and FIG. 12 shows the average orientation difference in crystal grains measured for the comparative coated tool 6. An example of the histogram is shown.

In addition, regarding the inclination angle number distribution of the hard coating layer, a column of a field emission scanning electron microscope with a cross section of the hard coating layer made of a composite carbonitride layer of Cr and Al having a cubic structure as a polished surface An electron beam with an acceleration voltage of 10 kV at an incident angle of 70 degrees is divided into a region on the surface (interface) side of the tool base and the region on the surface side, which is divided into two in the layer thickness direction. With an irradiation current of 1 nA, within the measurement range of the tool base side area and the surface side area in the direction perpendicular to the tool base, the width of 10 μm in the horizontal direction with respect to the tool base is 0.1 μm / step for five fields of view. Are irradiated with individual crystal grains having a cubic crystal lattice existing within the measurement range, and using the electron backscatter diffraction image apparatus, the normal of the tool base surface (perpendicular to the tool base surface on the cross-section polished surface) The crystal grains) The inclination angle formed by the normal of the {110} plane, which is the crystal plane, is measured. Based on the measurement result, the measurement inclination angle within the range of 0 to 45 degrees is set to 0.25 degrees among the measurement inclination angles. The ratio of the frequencies existing in the range of 0 to 12 degrees was obtained by summing up the frequencies existing in each section. The results are shown in Table 31 and Table 32.
FIG. 13 shows an example of an inclination angle number distribution measured for a region on the tool base side of a hard coating layer composed of a composite carbonitride layer of Cr and Al of the coated tool of the present invention, and FIG. An example of inclination angle number distribution measured about the area | region of the surface side of the hard coating layer which consists of a composite carbonitride layer of Cr and Al of a coating tool is shown.
Furthermore, analysis was performed at intervals of 0.1 μm from the longitudinal cross-section direction using an electron beam backscattering diffractometer, the width was 10 μm, and the vertical measurement within the measurement range of the film thickness was performed in five fields of view. The total number of pixels belonging to crystal grains having a cubic structure constituting the nitride or composite carbonitride layer is obtained, and the composite nitridation is performed according to the ratio to the total number of measured pixels in the measurement with respect to the hard coating layer in the five fields of view. The area ratio of crystal grains having a cubic structure constituting the product or composite carbonitride layer was determined.

Next, the coated tools 61 to 75 of the present invention, the comparative coated tools 61 to 73, and the reference coated tools, with the various coated tools clamped to the tool steel cutter tip with a cutter diameter of 125 mm by a fixing jig. About 74 and 75, the dry type high-speed face milling which is a kind of the high-speed intermittent cutting of carbon steel shown below, and the center cut cutting test were implemented, and the flank wear width of the cutting edge was measured. The results are shown in Table 33.

Tool substrate: Tungsten carbide-based cemented carbide, titanium carbonitride-based cermet,
Cutting test: dry high-speed face milling, center cutting,
Work material: Block material of JIS / S55C width 100mm, length 400mm,
Rotational speed: 765 min ⁻¹
Cutting speed: 300 m / min,
Cutting depth: 1.5 mm,
Single blade feed amount: 0.20 mm / tooth,
Cutting time: 8 minutes

At least (Cr _1-p Al _p ) (C _q ) on the surfaces of the tool bases α to γ and the tool base δ using the chemical vapor deposition apparatus and the conditions shown in Tables 28 and 29 by the same method as in Example 5. The coated tools 76 to 90 of the present invention shown in Table 35 were manufactured by vapor-depositing a hard coating layer including the N _1-q ) layer at a target layer thickness.
For the coated tools 79 to 88 of the present invention, the lower layer shown in Table 34 and / or the upper layer shown in Table 35 were formed under the formation conditions shown in Table 27.

For comparison, the present invention is also applied to the surfaces of the tool bases α to γ and the tool base δ by using an ordinary chemical vapor deposition apparatus under the conditions shown in Tables 28 and 29 and the target layer thicknesses shown in Table 36. Comparative coating tools 76-88 shown in Table 36 were produced by vapor-depositing a hard coating layer in the same manner as the coating tools.
Similar to the coated tools 79 to 88 of the present invention, the comparative coated tools 79 to 88 are formed with the lower layer shown in Table 34 and / or the upper layer shown in Table 36 under the forming conditions shown in Table 27. did.

For reference, the (Cr _1-p Al _p ) (C _q N _1-q ) layer of the reference example is formed on the surfaces of the tool base β and the tool base γ by arc ion plating using a conventional physical vapor deposition apparatus. The reference coated tools 89 and 90 shown in Table 36 were manufactured by vapor-depositing with a target layer thickness.
The arc ion plating conditions were the same as those shown in Example 5.

Further, the cross-sections of the constituent layers of the inventive coated tools 76 to 90, the comparative coated tools 76 to 88 and the reference coated tools 89 and 90 were measured using a scanning electron microscope (magnification 5000 times), and 5 in the observation field of view. When the layer thicknesses of the points were measured and averaged to obtain the average layer thickness, all showed the same average layer thickness as the target layer thicknesses shown in Tables 34 to 36.

Furthermore, the crystal orientation of the individual crystal grains having a cubic structure constituting the composite nitride or composite carbonitride layer of Cr and Al is analyzed from the longitudinal cross-section direction using an electron beam backscatter diffraction apparatus, The difference in direction is 0 degree or more, less than 1 degree, 1 degree or more, less than 2 degree, 2 degree or more, less than 3 degree, 3 degree or more, less than 4 degree, and so on. did. From the mapping diagram, the area ratio of the crystal grains having the average orientation difference in crystal grains and the orientation difference in crystal grains of 2 degrees or more to the entire composite nitride or composite carbonitride layer of Cr and Al was obtained. The results are shown in Table 35 and Table 36.

In addition, regarding the inclination angle number distribution of the hard coating layer, a column of a field emission scanning electron microscope with a cross section of the hard coating layer made of a composite carbonitride layer of Cr and Al having a cubic structure as a polished surface An electron beam with an acceleration voltage of 10 kV at an incident angle of 70 degrees is divided into a region on the surface (interface) side of the tool base and the region on the surface side, which is divided into two in the layer thickness direction. Is irradiated to each of the crystal grains having a cubic crystal lattice existing within the measurement range of the region on the tool base side and the region on the surface side with an irradiation current of 1 nA, and using an electron beam backscatter diffraction image apparatus, The crystal of the crystal grains with respect to the normal of the tool base surface (direction perpendicular to the tool base surface on the cross-section polished surface) at a spacing of 0.1 μm / step with a width of 10 μm and five fields of view in the horizontal direction. The slope formed by the normal of the {110} plane The angle is measured, and based on the measurement result, the measurement inclination angle within the range of 0 to 45 degrees is divided into the 0.25 degree pitches among the measurement inclination angles, and exists in each division. By counting the frequencies, the ratio of the frequencies existing in the range of 0 to 12 degrees was obtained. The results are shown in Table 35 and Table 36.

Next, the coated tools 76 to 90 of the present invention, the comparative coated tools 76 to 88, the reference coated tool 89, the reference coated tool 89, About 90, the dry high-speed intermittent cutting test of the carbon steel and the wet high-speed intermittent cutting test of ductile cast iron which were shown below were implemented, and all measured the flank wear width of the cutting edge.
Cutting condition 1:
Work material: JIS / S15C lengthwise equal length 4 vertical grooved round bars,
Cutting speed: 310 m / min,
Cutting depth: 2.0 mm
Feed: 0.27mm / rev,
Cutting time: 5 minutes
(Normal cutting speed is 220 m / min),
Cutting condition 2:
Work material: JIS / FCD450 lengthwise equidistant round bars with 4 vertical grooves,
Cutting speed: 340 m / min,
Incision: 1.5mm,
Feed: 0.27mm / rev,
Cutting time: 5 minutes
(Normal cutting speed is 200 m / min),
Table 37 shows the results of the cutting test.

From the results shown in Table 33 and Table 37, the coated tool of the present invention is a crystal grain having a cubic structure constituting a composite nitride or composite carbonitride layer of Al and Cr constituting the hard coating layer. In addition to the presence of a predetermined in-grain average orientation difference, the inclination angle formed by the normal line of the {110} plane in the region on the tool base side and the surface side of the crystal grain has a predetermined inclination angle number distribution. The distortion of the crystal grains improves the hardness and improves the 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 crystal grains having the cubic structure constituting the composite nitride of Al and Cr or the composite carbonitride layer constituting the hard coating layer, there is no predetermined intra-grain average orientation difference. Alternatively, the comparative coated tools 61 to 73, 76 to 88 in which the inclination angle formed by the normal of the {110} plane in the tool base side region and the surface side region of the crystal grains does not have a predetermined inclination angle number distribution, and The reference coated tools 74, 75, 89, and 90 are accompanied by high heat generation, and when used for high-speed intermittent cutting in which intermittent and shocking high loads act on the cutting edge, shorting occurs due to chipping and chipping. It is clear that the life is reached in time.

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.

P Measurement point (pixel)
B Grain boundary 1 Tool base 2 Hard coating layer 3 Composite nitride or composite carbonitride layer

Claims

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, and cubic boron nitride-based ultrahigh pressure sintered body,
(A) The hard coating layer is composed of a composite nitride or composite carbonitride layer of Ti and Al having an average layer thickness of 2 to 20 μm, or Ti, Al, and Me (where Me is Si, Zr, B, V A composite nitride or composite carbonitride layer of one element selected from Cr), or at least one of a composite nitride or composite carbonitride layer of Cr and Al,
(B) The composite nitride or composite carbonitride layer includes at least a composite nitride or composite carbonitride phase having a NaCl-type face-centered cubic structure,
(C) The crystal orientation of the crystal grains having the NaCl-type face-centered cubic structure among the crystal grains constituting the composite nitride or composite carbonitride layer is determined from the longitudinal sectional direction using an electron beam backscattering diffractometer. When the average orientation difference in each crystal grain is analyzed and the average orientation difference in each crystal grain is 2 degrees or more, the crystal grains having an average orientation difference in the crystal grain of 2 degrees or more are 20 in terms of the area ratio with respect to the total area of the composite nitride or composite carbonitride layer. % Exist,
(D) Furthermore, the inclination angle formed by the normal of the {110} plane, which is the crystal plane with respect to the normal direction of the tool substrate surface of the crystal grain, is equal to the composite nitride or the composite carbonitride layer in the layer thickness direction. The measured tool base side area and the surface side area are measured separately, and the measured tilt angle within the range of 0 to 45 degrees with respect to the normal direction among the measured tilt angles is 0.25 degrees. If you divide by pitch and count the frequency that exists in each division,
In the region on the tool base side, when the total of the frequencies existing in the range of 0 to 12 degrees is M deg with respect to the total frequencies in the tilt angle frequency distribution, M deg is 10 to 40%,
In the region on the surface side, the highest peak is present in the inclination angle section within the range of 0 to 12 degrees, and the total of the frequencies existing within the range of 0 to 12 degrees is relative to the entire frequency in the inclination angle frequency distribution. When the ratio of the Te and the N deg, the surface-coated cutting tool N deg is characterized in that it is a M deg + 10 ~ M deg + 30%.
The composite nitride or composite carbonitride layer is a composite nitride or composite carbonitride layer of Ti and Al, the composition of which is
Composition formula: (Ti 1-x Al x ) (C y N 1-y )
In the composite nitride or composite carbonitride layer, the average content ratio x avg in the total content of Ti and Al in Al and the average content ratio y avg in the total content of C and N in C (where x 2. The surface-coated cutting according to claim 1, wherein avg and y avg both satisfy an atomic ratio of 0.60 ≦ x avg ≦ 0.95 and 0 ≦ y avg ≦ 0.005 respectively tool.
The composite nitride or composite carbonitride layer is composed of Ti, Al, and Me (where Me is a kind of element selected from Si, Zr, B, V, and Cr) or a composite carbonitride. Layer, the composition of which
Composition formula: (Ti 1-α-β Al α Me β ) (C γ N 1-γ )
In the composite nitride or composite carbonitride layer, the average content ratio α avg in the total amount of Ti, Al, and Me of Al, the average content ratio β avg in the total amount of Me Ti, Al, and Me And the average content ratio γ avg (where α avg , β avg , and γ avg are atomic ratios) of the total amount of C and N in C and C are 0.60 ≦ α avg and 0.005 ≦ β avg , respectively. The surface-coated cutting tool according to claim 1, wherein ≦ 0.10, 0 ≦ γ avg ≦ 0.005, 0.605 ≦ α avg + β avg ≦ 0.95 is satisfied.
The composite nitride or composite carbonitride layer is a composite nitride or composite carbonitride layer of Cr and Al, the composition of which is
Composition formula: (Cr 1-p Al p ) (C q N 1-q )
In the composite nitride or composite carbonitride layer, the average content ratio p avg in the total content of Cr and Al in Al and the average content ratio q avg in the total content of C and N in C (p, 2. The surface-coated cutting according to claim 1, wherein avg and q avg are atomic ratios of 0.70 ≦ p avg ≦ 0.95 and 0 ≦ q avg ≦ 0.005, respectively. tool.
5. The composite nitride or composite carbonitride layer includes at least 70 area% or more of a composite nitride or composite carbonitride phase having a NaCl type face centered cubic structure. The surface-coated cutting tool according to claim 1.
The composite nitride or composite carbonitride layer is an average of individual grains having a NaCl-type face-centered cubic structure in the composite nitride or composite carbonitride layer when observed from the longitudinal cross-sectional direction of the layer. 6. The surface-coated cutting tool according to claim 1, wherein the surface-coated cutting tool has a columnar structure having a particle width W of 0.1 to 2 μm and an average aspect ratio A of 2 to 10.
Between the tool substrate and the composite nitride or composite carbonitride layer, one or more of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer and carbonitride layer The surface-coated cutting tool according to any one of claims 1 to 6, wherein a lower layer is formed of the Ti compound layer and has a total average layer thickness of 0.1 to 20 µm.
8. The upper layer including at least an aluminum oxide layer is formed on the composite nitride or composite carbonitride layer with a total average layer thickness of 1 to 25 μm. The surface-coated cutting tool according to Item.
The surface coating according to any one of claims 1 to 8, wherein the composite nitride or composite carbonitride layer is formed by a chemical vapor deposition method containing at least trimethylaluminum as a reaction gas component. Cutting tool manufacturing method.