WO2017073792A1

WO2017073792A1 - Surface-coated cutting tool, and production method therefor

Info

Publication number: WO2017073792A1
Application number: PCT/JP2016/082357
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 represented by the compositional formula (Cr_1-xAl_x)(C_yN_1-y), or a layer (3) of a composite nitride or composite carbonitride represented by the compositional formula (Ti_1-α-βAl_αMe_β)(C_γN_1-γ). Crystal grains which form the layer (3) of the composite nitride or composite carbonitride include crystal grains which have an NaCl-type face-centered cubic structure. The crystal grains having the NaCl-type face-centered cubic 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 and the like, and has high chipping resistance with a hard coating layer in high-speed intermittent cutting processing in which an impact load is applied to the cutting edge. The present invention relates to a surface-coated cutting tool (hereinafter referred to as a coated tool) that exhibits excellent wear resistance over a long period of use.
This application includes Japanese Patent Application No. 2015-214521 filed in Japan on October 30, 2015, Japanese Patent Application No. 2015-214525 filed in Japan on October 30, 2015, and Japanese Patent Application No. 2015-214525 on October 28, 2016. Priority is claimed based on Japanese Patent Application No. 2016-211143 filed in Japan, 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 A coated tool in which a Cr—Al-based or Ti—Al-based composite nitride layer is coated as a hard coating layer on the surface of a tool base (hereinafter collectively referred to as a tool base) by physical vapor deposition. These are known and are known to exhibit excellent wear resistance.
However, the above-mentioned coated tools coated with the conventional Cr-Al or Ti-Al composite nitride layer have relatively high wear resistance, but abnormalities such as chipping when used under high-speed interrupted cutting conditions. Various proposals for improvement of the hard coating layer have been made because of easy wear.

For example, Patent Document 1 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 2 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 a heat-resistant alloy such as precipitation hardened 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 3, in order to improve the fracture resistance of the 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.

Patent Document 4 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. A compound composed of at least one element selected from the group consisting of Group 4a, 5a, 6a group elements and Si, and at least one element selected from the group consisting of carbon, nitrogen, oxygen and boron And chlorine are disclosed to dramatically improve the wear resistance and oxidation resistance of the hard coating layer.

Further, for example, Patent Document 5 discloses that the value of the Al content ratio x is 0. by performing chemical vapor deposition in a temperature range of 650 to 900 ° C. in a mixed reaction gas of TiCl ₄ , AlCl ₃ , and NH ₃ . It is described that a (Ti _1-x Al _x ) N layer having a thickness of 65 to 0.95 can be formed by vapor deposition. In this document, an Al ₂ O layer is further formed on the (Ti _1-x Al _x ) N layer. _The formation of a (Ti _1-x Al _x ) N layer with the aim of covering _three layers and thereby increasing the thermal insulation effect, with the value of x increased from 0.65 to 0.95, There is no disclosure up to what point it has on cutting performance.

Further, in Patent Document 6, a TiCN layer and an Al ₂ O ₃ layer are used as inner layers, and a cubic crystal structure (Ti _1-x) including a cubic crystal structure or a hexagonal crystal structure is formed thereon by chemical vapor deposition. Al _x ) N layer (where x is 0.65 to 0.9) is coated as an outer layer, and by applying compressive stress of 100 to 1100 MPa to the outer layer, the heat resistance and fatigue strength of the coated tool are improved. It has been proposed to do.

Japanese Unexamined Patent Publication No. 2014-208394 (A) Japanese Unexamined Patent Publication No. 2014-198362 (A) Japanese Unexamined Patent Publication No. 2009-56539 (A) Japanese Unexamined Patent Publication No. 2006-82207 (A) Japan Special Table 2011-516722 Publication (A) Japanese National Table 2011-513594 (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 improve the adhesion strength between the lower layer and the upper layer by interposing and forming a CrAl compound and a Cr compound as an intermediate layer of the hard coating layer. Although the chipping property is improved, the strength and hardness of the CrAl compound and the Cr compound itself are not sufficient, so that when used for high-speed intermittent cutting, the chipping resistance and wear resistance are sufficient. I can't say that.
In the coated tool described in Patent Document 3, 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.
Further, the coated tool described in Patent Document 4 is intended to improve wear resistance and oxidation resistance, but it is resistant to chipping under cutting conditions such as high-speed interrupted cutting. There was a problem that the sex was not enough.
In addition, for the (Ti _1-x Al _x ) N layer formed by chemical vapor deposition described in Patent Document 5, 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 6 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.
Therefore, with high heat generation such as carbon steel, alloy steel, cast iron, etc., high-speed intermittent cutting with impact load on the cutting blade, chipping resistance with excellent hard coating layer, excellent wear resistance There is a need for a coated tool having both

In view of the above, the present inventors have at least a composite nitride or composite carbonitride of Cr and Al (hereinafter referred to as “(Cr, Al) (C, N)” or “(Cr _1−x Al _x ) (Which may be represented by (C _y N _1-y ))), and a coated nitride or composite carbonitride of at least Ti and Al (hereinafter referred to as “(Ti, Chipping resistance and wear resistance of a coated tool formed with a hard coating layer containing “Al) (C, N)” or “(Ti _1-α Al _α ) (may be represented by C _γ N _1-γ )” As a result of intensive studies to improve the sexiness, the following findings were obtained.

That is, it includes at least one conventional (Cr _1−x Al _x ) (C _y N _1−y ) layer or (Ti _1−α Al _α ) (C _γ N _1−γ ) layer and has a predetermined The hard coating layer having an average layer thickness of (Cr _1−x Al _x ) (C _y N _1−y ) layer or (Ti _1−α Al _α ) (C _γ N _1−γ ) layer is a tool. When it is formed in a columnar shape in the vertical direction on the substrate, it has high wear resistance. On the other hand, as the anisotropy of the (Cr _1−x Al _x ) (C _y N _1−y ) layer or (Ti _1−α Al _α ) (C _γ N _1−γ ) layer increases, (Cr _{1 -X} Al _x ) (C _y N _1-y ) layer or (Ti _1-α Al _α ) (C _γ N _1-γ ) layer has decreased toughness, resulting in chipping resistance and chipping resistance. As a result, the wear resistance could not be exhibited over a long period of use, and the tool life was not satisfactory.
Accordingly, the present inventors, constituting the hard layer _{_{_{(Cr 1-x Al x)}}} (C y N 1-y) layer, _{_{and, (Ti 1-α Al α}} ) (C γ N 1-γ) As a result of intensive research on the layers, it was found that the (Cr _1-x Al _x ) (C _y N _1-y ) layer and the (Ti _1-α Al _α ) (C _γ N _1-γ ) layer have Si, Zr, B (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) layer containing a kind of element selected from V, Cr and the like (hereinafter referred to as “Me”) is NaCl type. Including crystal grains having a face-centered cubic structure (hereinafter, sometimes simply referred to as “cubic structure”), and the average orientation difference in the crystal grains of the crystal grains having the cubic structure is set to 2 degrees or more. Through a new concept, we succeeded in producing strain in the crystal grains having a cubic structure and increasing both hardness and toughness. As a result, the inventors have found a novel finding that the chipping resistance and chipping resistance of the hard coating layer can be improved.

Furthermore, in the columnar crystal grains, a novel finding that the film surface side further improves the wear resistance while maintaining the toughness by increasing the ratio of the {100} orientation on the tool base surface side compared to the tool base surface side. I found.

In particular,
(1) Particularly when the hard coating layer includes at least a composite nitride or composite carbonitride layer of Cr and Al and is represented by a composition formula: (Cr _1-x Al _x ) (C _y N _1-y ) , The average content ratio x _avg in the total amount of Cr and Al in 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), respectively, The crystal grains satisfying 0.70 ≦ x _avg ≦ 0.95 and 0 ≦ y _avg ≦ 0.005 and having a cubic structure exist in the crystal grains constituting the composite nitride or composite carbonitride layer. When the crystal orientation of a grain 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, the crystal in which the average orientation difference in the crystal grain is 2 degrees or more By the presence of 20% or more of grains in the area ratio of the composite nitride or composite carbonitride layer, It can cause distortion in the crystal grains having a cubic crystal structure. Furthermore, wear resistance is improved by increasing the ratio of the {100} orientation on the surface side of the film as compared to the surface side of the tool base of the crystal grains. As a result, it has been found that a cutting tool having such a hard coating layer has improved wear resistance and chipping resistance and exhibits excellent wear resistance over a long period of time.
Also,
(2) The hard coating layer includes 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). When expressed by the composition formula: (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ), in particular, the average content ratios α _avg and Me in the total amount of Ti of Ti, Al, and Me average content accounted for the total amount of Ti, Al and Me beta _avg and C of C and average proportion occupied in the total amount of N gamma _avg _{_{(where, α avg, β avgg, γ}} avg any atomic ratio) 0.60 ≦ α _avg , 0.005 ≦ β _avg ≦ 0.10, 0 ≦ γ _avg ≦ 0.005, 0.605 ≦ α _avg + β _avg ≦ 0.95, respectively, A cubic structure is formed in the grains constituting the composite carbonitride layer. When 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 within each crystal grain is determined, the average orientation difference within the crystal grain When the crystal grains exhibiting 2 degrees or more are present in an area ratio of 20% or more of the composite nitride or composite carbonitride layer, the crystal grains having a cubic structure can be distorted. Furthermore, wear resistance is improved while maintaining toughness by increasing the ratio of the {100} orientation on the film surface side compared to the tool substrate surface side of the crystal grains. As a result, it has been found that a cutting tool having such a hard coating layer has improved chipping resistance and fracture resistance and exhibits excellent wear resistance over a long period of time.

The (Cr _1−x Al _x ) (C _y N _1−y ) layer and the (Ti _1−α−β Al _α Me _β ) (C _γ N _1−γ ) layer configured as described above are For example, the film can be formed by the following chemical vapor deposition method in which the reaction gas composition is periodically changed on the tool substrate surface.

(1) Regarding the (Cr _1-x Al _x ) (C _y N _1-y ) Layer The chemical vapor deposition reactor used includes a gas group A composed of NH ₃ and H ₂ , CrCl ₃ , AlCl ₃ , Al (CH ₃ ) A gas group B composed of ₃ , N ₂ and H ₂ is supplied into the reactor from the separate gas supply pipes, and the supply of the gas group A and the gas group B into the reactor is, for example, at a constant cycle. In such a time interval, the gas is supplied so that the gas flows for a time shorter than the period, and the gas supply of the gas group A and the gas group B has a phase difference shorter than the gas supply time. The reaction gas composition on the surface is changed temporally with gas group A (first reaction gas), mixed gas of gas group A and gas group B (second reaction gas), and gas group B (third reaction gas). Can do. 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.
The reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) on the surface of the tool base is, for example, NH ₃ : 4.5 to 5.5% as the gas group A, and H ₂ : 65 to 75. %, AlCl ₃ : 0.6 to 0.9% as gas group B, CrCl ₃ : 0.2 to 0.3%, Al (CH ₃ ) ₃ : 0 to 0.5%, N ₂ : 12.5 ∼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 By performing the thermal CVD method for a predetermined time with a phase difference of 0.10 to 0.20 seconds for the supply of the gas group A and the gas group B for 0.25 seconds, (Cr _1-x Al _x ) (C _y N _1-y ) layer is formed.

Then, as described above, the gas group A and the gas group B are supplied so as to have 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 4.5 to 5.5%. 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 {100} 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 and H ₂ , TiCl ₄ , Al ( A gas group B consisting of CH ₃ ) ₃ , AlCl ₃ , MeCl _n (Me chloride), N ₂ , and H ₂ is supplied into the reactor through a separate gas supply pipe. The supply into the reactor is, for example, such that the gas flows at a constant cycle time interval for a time shorter than the cycle, and the gas supply for the gas group A and the gas group B is more than the gas supply time. The reaction gas composition on the surface of the tool base is changed to gas group A (first reaction gas), gas mixture of gas group A and gas group B (second reaction gas), gas group B so that a phase difference of a short time occurs. (Third reaction gas) and time can be changed. 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 is possible to realize.
The reaction gas composition (volume% with respect to the total of the gas group A and the gas group B) on the surface of the tool base is, for example, NH ₃ : 4.0 to 6.0% as the gas group A, H ₂ : 65 to 75. %, As gas group B, AlCl ₃ : 0.6 to 0.9%, TiCl ₄ : 0.2 to 0.3%, MeCl _n (Me chloride): 0.1 to 0.2%, Al ( CH ₃ ) ₃ : 0 to 0.5%, N ₂ : 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 period 1 to 5 seconds, gas supply time per cycle 0.15 to 0.25 seconds, phase difference 0.10 to 0.20 seconds of supply of gas group A and gas group B, predetermined time, thermal CVD by performing law, to deposit a predetermined target layer thickness of _{(Ti 1-α-β Al} α Me β) (C γ N 1-γ) layer The

Then, as described above, the gas group A and the gas group B are supplied so that there is a difference in the time for reaching the tool base surface, and NH ₃ as the nitrogen source gas in the gas group A is 4.0 to 6.0%. 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 {100} orientation of the crystal grains on the tool base surface side and the coating surface side can be changed. As a result, it has been found that toughness is dramatically improved while maintaining wear resistance. As a result, especially when used for high-speed intermittent cutting of alloy steel, etc., where the chipping resistance and chipping resistance are improved, and the intermittent and impact loads are applied to the cutting edge, It has been found that excellent cutting performance can be exhibited over use.

This invention is made | formed based on the said knowledge, Comprising: It has the aspect shown below.
“(1) Surface coating in which a hard coating layer is formed on the surface of a tool base made of any of tungsten carbide-based cemented carbide, titanium carbonitride-based cermet, and cubic boron nitride-based ultrahigh-pressure sintered body In cutting tools,
(A) The hard coating layer is composed of a composite nitride or composite carbonitride layer of Cr 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 compound nitride of at least one element selected from Cr) or a composite carbonitride layer,
(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. Analyzing and obtaining the average orientation difference within each crystal grain When the average orientation difference within the crystal grain is 2 degrees or more, the crystal grains are in an area ratio relative to the total area of the composite nitride or composite carbonitride layer. 20% or more
(D) Further, the inclination angle formed by the normal line of the {100} plane which is the crystal plane with respect to the normal direction of the surface of the tool base 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 Cr and Al, the composition of which is
Composition formula: (Cr _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 amount of Cr and Al in Al and the average content ratio y _avg in the total amount of C and N in C (where x The surface coating according to (1), wherein _avg and y _avg are atomic ratios of 0.70 ≦ 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 contains at least 70 area% or more of a composite nitride or composite carbonitride phase having a NaCl type face centered cubic structure. Thru | or the surface-coated cutting tool in any one of said (3).
(5) The composite nitride or the composite carbonitride layer is an individual crystal having a NaCl-type face-centered cubic structure in the composite nitride or the composite carbonitride layer when observed from the longitudinal section direction of the layer. The surface-coated cutting according to any one of (1) to (4) 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 tool.
(6) Between the tool base and the composite nitride or composite carbonitride layer, one of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer and carbonitride oxide layer or The surface-coated cutting according to any one of (1) to (5) 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. tool.
(7) The upper layer including at least an aluminum oxide layer is formed on the composite nitride or the composite carbonitride layer with a total average layer thickness of 1 to 25 μm. The surface-coated cutting tool according to any one of (6).
(8) The composite nitride or the composite carbonitride layer is formed by a chemical vapor deposition method containing at least trimethylaluminum as a reactive gas component, according to any one of (1) to (7), The manufacturing method of the surface coating cutting tool of description. "
It has the characteristics.
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 contains at least an average layer thickness 2 composite nitride of ~ 20 [mu] m of Cr and Al or composite carbonitride layer, the composition _{_{_{formula: (Cr 1-x Al x}}} ) (C y N 1-y ) In particular, the average content ratio x _avg in the total amount of Cr and Al in 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 both Atomic ratio) satisfy 0.70 ≦ x _avg ≦ 0.95 and 0 ≦ y _avg ≦ 0.005, respectively, and a cubic structure is formed in the crystal grains constituting the composite nitride or composite carbonitride layer. The crystal orientation of the crystal grains, and the electron beam backscatter diffraction apparatus When the average orientation difference within each crystal grain is determined by analyzing from the longitudinal cross-sectional direction using the crystal, the crystal grain showing the average orientation difference within the crystal grain of 2 degrees or more is the composite nitride or the entire composite carbonitride layer The composite nitride or the composite carbonitride layer has an inclination angle formed by the normal of the {100} plane, which is a crystal plane with respect to the normal direction of the tool base surface of the crystal grain. Is measured by dividing it into a tool base side region and a surface side region that are divided into two equal parts in the layer thickness direction, and the measured tilt angle is in the range of 0 to 45 degrees with respect to the normal direction among the measured tilt angles. When the 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, the sum of the frequencies existing in the range of 0 to 12 degrees is inclined. When the ratio of the relative total power in the angular speed distribution and M _{_deg,} M _deg 10 to B) 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 sum of the frequencies existing within the range of 0 to 12 degrees is the inclination angle. Assuming that the ratio of the number distribution to the entire frequency is N _deg , N _deg is M _deg +10 to M _deg + 30%, and when the composite nitride or the composite carbonitride layer is observed from the cross section side of the film By having a columnar structure with an average grain width W of 0.1 to 2 μm and an average aspect ratio A of 2 to 10 for each crystal grain having a cubic structure in the composite nitride or composite carbonitride layer, Since distortion occurs in the crystal grains having a cubic crystal structure, the hardness and toughness of the crystal 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.
In the surface-coated cutting tool in which a hard coating layer is provided on the surface of the tool base, the hard coating layer has an average layer thickness of 1 to 20 μm, preferably 2 to 20 μm of a composite nitride of Ti, Al, and Me or When it includes at least a composite carbonitride layer and is expressed by a composition formula: (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ), in particular, Al of the composite nitride or the composite carbonitride layer The average content ratio α _avg in the total amount of Ti, Al, and Me of Ti and the average content ratio β _avg in the total amount of Ti, Al, and Me of Me and the average content ratio γ _avg in the total amount of C and N of C (Where α _avg , β _avg , and γ _avg are all atomic ratios) are 0.60 ≦ α _avg , 0.005 ≦ β _avg ≦ 0.10, 0 ≦ γ _avg ≦ 0.005,. 605 ≦ α _avg + β _avg ≦ 0.9 5 is satisfied, and the crystal grains constituting the composite nitride or composite carbonitride layer have a cubic structure, and the crystal orientation of the crystal grains is determined by using the electron backscatter diffraction apparatus in the longitudinal section direction. In the case where the average orientation difference in each crystal grain is calculated, the crystal grains having an average orientation difference in the crystal grains of 2 degrees or more are in an area ratio with respect to the entire composite nitride or composite carbonitride layer. The tilt angle formed by the normal line of the {100} plane, which is a crystal plane with respect to the normal direction of the tool base surface of the crystal grains, is 20% or more in the thickness direction of the composite nitride or composite carbonitride layer. The measurement is performed by dividing into a tool base side region and a surface side region which are equally divided, and a measured inclination angle within a range of 0 to 45 degrees with respect to the normal direction among the measured inclination angles is 0.25 degrees. When the frequency in each section is tabulated and the frequency existing in each section is tabulated, a) Tool base The side regions, the total power present in the range of 0 to 12 degrees, when the ratio of the relative total power at the inclination angle frequency distribution and M _deg, M _deg is 10 ~ 40%, b) 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, N _deg is _{_{M deg + 10 ~ M deg +}} 30%, the on composite nitride or composite carbonitride layer, when viewed from the film section side, composite nitride or complex carbonitride Crystal grains having a cubic structure by having a columnar structure with an average grain width W of 0.1 to 2 μm and an average aspect ratio A of 2 to 10 for individual grains having a cubic structure in the nitride layer Because of distortion in the crystal Hardness and toughness are improved in. 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 present invention has a NaCl-type face-centered cubic structure (cubic crystal) of a composite nitride or composite carbonitride layer of Cr and Al, or a composite nitride or composite carbonitride layer of Ti, Al and Me. The schematic explanatory drawing of the measuring method of the crystal grain average orientation difference of a crystal grain is shown. A cross section of a composite nitride or composite carbonitride layer of Cr and Al or a composite nitride or composite carbonitride layer of Ti, Al, and Me constituting the hard coating layer of the surface-coated cutting tool of the present invention FIG. In a 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 in-grain misorientation (GOS) of individual grains having a NaCl type cubic structure 2 shows an example of a histogram for an area ratio of (value). The vertical dotted line 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 vertical dotted line in the figure has an average misorientation within the grain of 2 ° or more. The thing is shown. The same applies to FIGS. 4 to 6 below. Comparative example In-grain average orientation difference (GOS) of individual grains having a NaCl-type cubic structure 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 2 shows an example of a histogram for an area ratio of (value). Intra-grain average orientation difference of individual crystal grains having a cubic structure of NaCl type 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 It shows an example of a histogram for the area ratio of (GOS value). In-grain average orientation difference of individual grains having a cubic structure of NaCl type 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 It shows an example of a histogram for the area ratio of (GOS value). It is an example of the inclination angle number distribution graph of the {100} 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. Hereinafter, the definition of the total frequency is the same in FIGS. 8 to 10. It is an example of the inclination angle number distribution graph of the {001} 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. It is an example of the inclination angle number distribution graph of the {100} plane created in the area | region of 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. . It is an example of the inclination angle number distribution graph of the {100} plane created 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.

DETAILED DESCRIPTION A mode for carrying out the present invention will be described below.

Average layer thickness of the composite nitride or composite carbonitride layer constituting the hard coating layer:
The hard coating layer possessed by the surface-coated cutting tool of the present invention is a chemical vapor-deposited compositional formula: (Cr _1-x Al _x ) (C _y N _1-y ) represented by a composite nitride or composite of Cr and Al Carbon nitride layer or chemical vapor deposited composition formula: (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) Ti, Al and Me composite nitride or composite carbon At least a nitride layer is included.
These composite nitride or composite carbonitride layers of Cr and Al, and composite nitride or composite carbonitride layers of Ti, Al, and Me have high high temperature hardness and excellent wear resistance. When the average layer thickness is 2 to 20 μm, the effect is remarkably exhibited. The reason is that the average layer thickness is less than 2 μm in the composite nitride or composite carbonitride layer of Cr and Al, and less than 1 μm in the composite nitride or composite carbonitride layer of Ti, Al, and Me, Since the layer thickness is thin, sufficient wear resistance over a long period of use cannot be ensured. On the other hand, if the average layer thickness exceeds 20 μm, the composite nitride or composite carbonitride layer of Cr and Al Crystal grains 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) About the composite nitride or composite carbonitride layer of Cr and Al of the present invention When expressed by the composition formula: (Cr _1-x Al _x ) (C _y N _1-y ), the Cr and Al of Al The average content ratio x _avg in the total 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 0.70 ≦ x _avg ≦ It is preferable to control to satisfy 0.95 and 0 ≦ y _avg ≦ 0.005.
The reason is that if the average content ratio x _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 x _{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 x _avg was determined to be 0.70 ≦ 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 substrate or the lower layer is improved and the lubricity is improved to reduce the impact during cutting. 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 layer of Ti, Al, and Me of the present invention When represented by the composition formula: (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) (Where 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 Ti, Al, and Me in Me The average content ratio β _avg in the total amount of C 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, respectively. ≦ α _avg , 0.005 ≦ β _avg ≦ 0.10, 0 ≦ γ _avg ≦ 0.005, 0.605 ≦ α _avg + β _avg ≦ 0.95 are preferably controlled.
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.

Intra-grain average orientation difference (GOS value) of individual crystal grains having a NaCl-type face-centered cubic structure constituting the composite nitride or composite carbonitride layer:
In the present invention, an electron beam backscatter diffractometer is used to determine the average orientation difference in cubic Cr and Al composite nitride or composite carbonitride crystal grains, and cubic Ti, Al and Me. The average orientation difference within the crystal grains of the composite nitride or composite carbonitride crystal grains is determined.
Specifically, the surface polished surface is analyzed at intervals of 0.1 μm from the direction perpendicular to the surface of the composite nitride or composite carbonitride layer, and as shown in FIG. Hereinafter, when there is an azimuth difference of 5 degrees or more between them (also referred to as “pixel”), this is defined as a grain boundary B. 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, the orientation difference between a certain pixel P in a crystal grain having a cubic crystal structure and all other pixels in the same crystal grain is calculated, and this is obtained as the orientation difference in the crystal grain, and is averaged. Things are defined as GOS (Grain Orientation Spread) values. 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 the GOS value. When the GOS value is expressed by a mathematical expression, the number of pixels in the same crystal grain is n, the numbers given to the different pixels P in the same crystal grain are i and j (where 1 ≦ i, j ≦ n), The crystal orientation difference obtained from the crystal orientation at the pixel i and the crystal orientation at the pixel j can be expressed by the following equation, with α _{ij (i ≠ j)} .
Note that the average orientation difference and GOS value within a crystal grain are values obtained by calculating the orientation difference between a pixel in a crystal grain and all other pixels in the same crystal grain, and averaging the values. However, a large numerical value is obtained when there are many continuous orientation changes in the crystal grains.

In-grain average orientation difference (GOS value) from the direction perpendicular to the surface of the composite nitride or composite carbonitride layer of Cr and Al, or the composite nitride or composite carbonitride layer of Ti, Al and Me Using the electron beam backscattering diffractometer on the polished surface, measurement within a measurement range of 25 × 25 μm was performed at intervals of 0.1 μm / step in five fields of view, and the composite nitride or composite carbonitride Calculate the total number of pixels belonging to the crystal grains having a cubic structure constituting the layer, divide the average misorientation within the grain at intervals of 1 degree, and include the average misorientation within the grain within the range of the value The total number of pixels P is divided and divided by the total number of pixels to obtain a histogram showing the area ratio of the average orientation difference in crystal grains.
3 to 6 show examples of histograms created in this way.

FIG. 3 is an example of a histogram of average orientation difference in crystal grains obtained for a crystal grain having a cubic structure of Cr and Al composite nitride or composite carbonitride layer of the cutting tool according to the present invention. As shown in FIG. 3, the area ratio of the crystal grains having a mean grain orientation difference (GOS) value of 2 degrees or more to the total area of the composite nitride or composite carbonitride layer of Cr and Al is 20 It turns out that it is more than%.
On the other hand, FIG. 4 is an example of a histogram of the average orientation difference in the crystal grains obtained for the crystal grains having the cubic structure of the composite nitride or composite carbonitride layer of Cr and Al of the comparative tool. In FIG. 4, the area ratio of the crystal grains having a mean grain orientation difference (GOS) value of 2 degrees or more to the total area of the composite nitride or composite carbonitride layer of Cr and Al is less than 20%. is there.
FIG. 5 is an example of a histogram of the average orientation difference in crystal grains obtained for crystal grains having a cubic structure of a composite nitride or composite carbonitride layer of Ti, Al, and Me of the cutting tool according to the present invention. However, as shown in FIG. 5, the total area of the composite nitride or composite carbonitride layer of Ti, Al, and Me is a crystal grain having a mean grain orientation difference (GOS) value of 2 degrees or more. It can be seen that the area ratio in the area is 20% or more.
On the other hand, FIG. 6 is an example of a histogram of average orientation difference in crystal grains obtained for a crystal grain having a cubic structure of a composite nitride or composite carbonitride layer of Ti, Al, and Me of a comparative tool. However, in FIG. 6, the area ratio of the crystal grains having the average grain orientation difference (GOS) value of 2 degrees or more to the total area of the composite nitride or composite carbonitride layer of Ti, Al, and Me Is less than 20%.
Thus, the cutting tool according to the present invention has a cubic structure that constitutes a composite nitride or composite carbonitride layer of Cr and Al, and a composite nitride or composite carbonitride layer of Ti, Al, and Me. The crystal grains have a large variation in crystal orientation within the crystal grains as compared with the conventional ones. Therefore, the higher strain within the crystal grains contributes to the improvement of hardness and toughness.
Then, the (Cr _1-x Al _x ) (C _y N _1-y ) layer or the (Ti _1-α-β Al _α Me _β ) (C _γ N _1-γ ) having the average orientation difference in crystal grains. ) Coated tools with a hard coating layer containing at least a layer on the tool substrate surface are excellent in high-speed intermittent cutting of alloy steel and the like that cause high heat generation and impact load on the cutting edge. It exhibits chipping resistance and wear resistance.
However, Cr and Al composite nitride or composite carbonitride layer, or Ti, Al and Me composite nitride or composite carbonitride layer of the crystal grains in which the average orientation difference in crystal grains is 2 degrees or more When the area ratio in the total area is less than 20%, the effect of improving the hardness and toughness due to the internal strain of the crystal grains is not sufficient. The area ratio of the crystal grains having the total area of the composite nitride or composite carbonitride layer of Ti, Al, and Me is 20% or more.
Thus, the crystal grains constituting the composite nitride or composite carbonitride layer of Al, Ti and Me of the surface-coated cutting tool of the present invention are compared with the crystal grains constituting the conventional TiAlN layer, Since the crystal orientation varies greatly within the crystal grains, that is, there is distortion, this contributes to the improvement of 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%. Furthermore, the area ratio of the crystal grains in which the average orientation difference in the crystal grains is 2 degrees or more with respect to the area of the composite nitride or composite carbonitride layer 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 the composite carbonitride layer have a surface side facing the normal direction of the tool base surface, that is, the {100} plane, rather than the tool base surface (tool base) side. Thus, an effect peculiar to the present invention that wear resistance is improved while maintaining toughness is exhibited.
However, if the increase rate of the {100} plane orientation degree on the surface side relative to the tool base side is less than 10%, the increase rate of the {100} plane orientation degree is small and wear resistance is maintained while maintaining the toughness expected in the present invention. The effect of improving the performance is not sufficiently achieved. 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. When the {100} plane orientation degree on the tool base side is less than 10%, the increase rate of the {100} plane orientation degree on the surface side is larger than 30%, and the {100} plane orientation degree on the tool base side exceeds 40%. It was found that the increase rate of the degree of {100} plane orientation on the surface side was less than 10%. Accordingly, the tool base side obtained by dividing the inclination angle formed by the normal of the {100} plane, which is the 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 total number of frequencies present is When a slip and N _{_deg,} N _deg is defined to be _{_{M deg + 10 ~ M deg +}} 30%.

Crystal structure of hard coating layer:
When the hard coating layer has a cubic structure single phase, particularly excellent wear resistance is exhibited. Further, even when the hard coating layer is not a cubic structure single phase, the hard coating layer is analyzed at an interval of 0.1 μm from the longitudinal cross-sectional direction using an electron beam backscattering diffractometer, and the width is 10 μm. The measurement from the longitudinal cross-sectional direction within the measurement range of the film thickness is carried out in five fields of view, and the total number of pixels belonging to the crystal grains having a cubic structure constituting the composite nitride or composite carbonitride layer is obtained, When the area ratio of the crystal grains having the cubic structure constituting the composite nitride or composite carbonitride layer was determined by the ratio to the total number of pixels measured in the hard coating layer in five fields of view, the cubic crystal When the area ratio of the crystal grains having a structure is less than 70%, a tendency to decrease the wear resistance is observed. On the other hand, when the area ratio is 70% or more, excellent chipping resistance and wear resistance are observed. From the fact that The phase of Ti, Al and Me composite nitride or composite carbonitride having a tetragonal structure is desirably 70 area% or more.

Average grain width W and average aspect ratio A of individual grains having a cubic structure in the composite nitride or composite carbonitride layer:
The average grain width W of the individual crystal grains having a cubic structure in the composite nitride or composite carbonitride layer of Cr and Al, or in the composite nitride or composite carbonitride layer of Ti, Al, and Me is 0 By configuring the columnar structure so that the average aspect ratio A is 2 to 10 and the average aspect ratio A is 2 to 10, the above-described effect of improving toughness and wear resistance can be further exhibited.
That is, the average particle width W is set to 0.1 to 2 μm because, if it is less than 0.1 μm, the proportion of the atoms belonging to the CrAlCN crystal grain boundary or TiAlMeCN crystal grain boundary in the atoms exposed on the coating layer surface is relatively As a result, the reactivity with the work material increases, and as a result, the wear resistance cannot be sufficiently exhibited, and if it exceeds 2 μm, the CrAlCN grain boundary in the entire coating layer, or When the proportion of atoms belonging to the TiAlMeCN crystal grain boundary is 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:
Moreover, the composite nitride or composite carbonitride layer of Cr and Al or the composite nitride or composite carbonitride layer of Ti, Al, and Me possessed by the surface-coated cutting tool of the present invention alone is sufficient effect. It consists of one or two or more Ti compound layers of Ti carbide layer, nitride layer, carbonitride layer, carbonate layer and carbonitride oxide layer, and a total of 0.1 to 20 μm When a lower layer having an average layer thickness is provided and / or when an upper layer including at least an aluminum oxide layer is provided with a total average layer thickness of 1 to 25 μm, this is in combination with the effects of these layers. Thus, superior characteristics can be created. 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. Further, 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. .

A cross section of a composite nitride or composite carbonitride layer of Cr and Al or a composite nitride or composite carbonitride layer of Ti, Al, and Me constituting the hard coating layer of the surface-coated cutting tool of the present invention A diagrammatic representation is shown in FIG.

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, and the formation conditions A to J shown in Table 3, Table 4, and Table 5, that is, the gas group A composed of NH ₃ and H _2, and , CrCl ₃ , AlCl ₃ , Al (CH ₃ ) ₃ , N ₂ , H ₂ , and a method of supplying each gas, the reaction gas composition (capacity relative to the total of the gas group A and the gas group B combined) %) As gas group A, NH ₃ : 4.5 to 5.5%, H ₂ : 65 to 75%, as gas group B, AlCl ₃ : 0.6 to 0.9%, CrCl ₃ : 0.2 ~ 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 Atmospheric temperature: 750 to 900 ° C, supply cycle 1 to 5 seconds, gas supply time per cycle 0 The thermal CVD method is performed for a predetermined time with a phase difference of 0.10 to 0.20 seconds for the supply of gas group A and gas group B for 15 to 0.25 seconds. (Cr _1-x Al _x ) (C _y N _1-y ) layer having a crystal structure having a cubic structure showing two degrees or more, having an area ratio shown in Table 7, and having a target layer thickness shown in Table 7 The coated tools 1 to 15 of the present invention were produced by forming a hard coating layer made of
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, the surfaces of the tool bases A to D are the same as the coated tools 1 to 15 of the present invention under the conditions shown in Tables 3, 4 and 5 and the target layer thickness (μm) shown in Table 8. A hard coating layer including at least a composite nitride or composite carbonitride layer of Cr and Al was formed by vapor deposition. 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-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 (Cr _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—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 A current of 120 A is passed between the cathode electrode (evaporation source) made of the Al—Cr alloy and the anode electrode to generate an arc discharge, and the target composition and target layer shown in Table 8 are formed on the surface of the tool base. A thick (Cr, Al) N layer was formed by vapor deposition to produce reference coated tools 14 and 15.

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 determined by measuring and averaging the five layer thicknesses within the observation field of view, both showed substantially the same average layer thickness as the target layer thicknesses shown in Table 7 and Table 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 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 _yavg .

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 7 and Table 8.
FIG. 3 shows an example of a histogram of the average orientation difference in crystal grains (that is, the GOS value) measured for the coated tool 5 of the present invention, and FIG. 4 shows the average orientation difference in crystal grains measured for the comparative coated tool 2. 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 {100} plane that is the crystal plane is measured, and based on the measurement result, the measurement inclination angle within the range of 0 to 45 degrees is set to 0.25 degrees out of 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. 7 shows an example of the inclination angle number distribution measured for the region on the tool base side of the hard coating layer composed of the 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 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. For 14 and 15, the following dry 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 9.

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: 866 min ⁻¹
Cutting speed: 340 m / min,
Cutting depth: 1.5 mm,
Single blade feed amount: 0.10 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 each having an average particle diameter of 1 to 3 μm are prepared. Compounded in the formulation shown in Table 10, added with wax, ball mill mixed in acetone for 24 hours, dried under reduced pressure, press-molded into a green compact of a predetermined shape at a pressure of 98 MPa. In a 5 Pa vacuum, vacuum sintering is performed at a predetermined temperature within a range of 1370 to 1470 ° C. for 1 hour, and after sintering, the cutting edge is subjected to a honing process of R: 0.07 mm. Tool bases α to γ made of WC-base cemented carbide having the insert shape of CNMG120212 were manufactured.

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

Next, at least (Cr ₁ the _-x Al _x) _(that C _{y N 1-y)} layer is deposited formed at the target layer thickness of the hard coating layer containing was prepared present invention coated tool 16-30 shown in Table 13.
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.

Further, for comparison purposes, a normal chemical vapor deposition apparatus was used on the surfaces of the tool bases α to γ and the tool base δ, and the target layer thicknesses shown in Table 3 and Tables 4 and 5 and the target layer thicknesses shown in Table 14 were used. Comparative coating tools 16 to 28 shown in Table 14 were produced by vapor-depositing a hard coating layer in the same manner as the coating tool of the present invention.
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 (Cr _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 layer thicknesses of the points were measured and averaged to determine the average layer thickness, both showed the average layer thickness substantially the same as the target layer thickness shown in Table 13 and Table 14.

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 13 and Table 14.

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 {100} 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, in the state where all the various coated tools are 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, 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 / S15C lengthwise equal length 4 vertical grooved round bars,
Cutting speed: 430 m / min,
Incision: 1.5mm,
Feed: 0.22mm / 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: 410 m / min,
Cutting depth: 1.0 mm,
Feed: 0.22mm / 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 Tables 9 and 15, the coated tool of the present invention is a crystal grain having a cubic structure constituting the 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 tilt angle formed by the normal of the {100} plane in the tool base side region and the surface side region of the crystal grain has a predetermined tilt 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. The comparative coated tools 1 to 13, 16 to 28 in which the inclination angle formed by the normal of the {100} plane in the region on the tool base side and the region on 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.

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 16. 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. WC-based cemented carbide tool bases E to G with ISO standard SEEN1203AFSN insert shape after vacuum sintering under the condition of holding for 1 hour at a predetermined temperature within the range of ~ 1470 ° C. 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 17, 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 H 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 E to H, and the formation conditions shown in Tables 19 and 20, that is, a gas group A composed of NH ₃ 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 ), gas group B consisting of N ₂ , H ₂ , and supply of each gas As a method, the reaction gas composition (capacity% with respect to the total of the gas group A and the gas group B) is set to NH ₃ : 4.0 to 6.0%, H ₂ : 65 to 75%, gas group As B, AlCl ₃ : 0.6 to 0.9%, TiCl ₄ : 0.2 to 0.3%, Al (CH ₃ ) ₃ : 0 to 0.5%, MeCl _n (however, SiCl ₄ , ZrCl ₄ , BCl ₃ , VCl ₄ , Cr Any of Cl ₂ ): 0.1 to 0.2%, 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, phase difference between gas group A and gas group B supply 0.10 to 0.20 seconds Then, the thermal CVD method is performed for a predetermined time, and the crystal grains having a cubic structure in which the average misorientation within the crystal grains shown in Table 22 is 2 degrees or more are present in the area ratio shown in Table 22, 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.
For the inventive coated tools 36 to 43, the lower layer shown in Table 21 and / or the upper layer shown in Table 22 were formed under the formation conditions shown in Table 18.

For comparison purposes, at least on the surfaces of the tool bases E to H, at the conditions shown in Tables 19 and 20 and the target layer thickness (μm) shown in Table 23, at least as in the coated tools 31 to 45 of the present invention. A hard coating layer including a composite nitride or composite carbonitride layer of Ti, Al, and Me 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.
Similar to the coated tools 36 to 43 of the present invention, the comparative coated tools 36 to 43 are formed with the lower layer shown in Table 21 and / or the upper layer shown in Table 23 under the forming conditions shown in Table 18. 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 21 to Table 23.

The average Al content ratio and the average Me content ratio of the composite nitride or composite carbonitride layer were measured using an electron beam microanalyzer (Electron-Probe-Micro-Analyzer: EPMA) in a sample whose surface was polished. A line was irradiated from the sample surface side, and an average Al content rate α _{avg of} Al and an average content rate β _avg of Me were obtained from an average of 10 points of the analysis result of the obtained characteristic X-rays. The average C content γ _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 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 22 and Table 23.

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 every 1 degree and mapped. 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 22 and Table 23.
FIG. 5 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. 6 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 inclination angle formed by the normal line of the {100} plane, which is the crystal plane of the crystal grain, is measured. Based on the measurement result, the measurement inclination angle within the range of 0 to 45 degrees out of the measurement inclination angles is set to 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 22 and Table 23.
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 22 and Table 23.

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 22 and Table 23.

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 24.

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: 892 min ⁻¹
Cutting speed: 350 m / min,
Cutting depth: 1.5 mm,
Single blade feed: 0.1 mm / tooth,
Cutting time: 8 minutes.

As raw material powders, both WC powder having an average particle size of 1 ~ 3 [mu] m, TiC powder, ZrC powder, TaC powder, NbC powder, _Cr 3 _{C 2} powder, prepared TiN powder and Co powder, these raw material powders, Blended in the composition shown in Table 25, further added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, pressed 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 ε to η made of a WC-base cemented carbide having an insert shape of CNMG120212 were produced.

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 26, wet-mixed for 24 hours with a ball mill, dried, and then pressed into green compacts 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 θ was formed.

Next, on the surfaces of these tool bases ε to η and tool base θ, at least (Ti _{1-α- The} coated tools 46 to 60 of the present invention shown in Table 28 were manufactured by vapor-depositing a hard coating layer including a _β Al _α Me _β ) (C _γ N _1-γ ) layer with a target layer thickness.
For the inventive coated tools 49 to 58, the lower layer shown in Table 27 and / or the upper layer shown in Table 28 were formed under the formation conditions shown in Table 18.

Also, for comparison purposes, the coated tool of the present invention was used under the conditions shown in Tables 19 and 20 and the target layer thicknesses shown in Table 29 using a chemical vapor deposition apparatus on the surfaces of the tool bases ε to η and the tool base θ. Comparative coating tools 46 to 60 shown in Table 29 were manufactured by vapor-depositing a hard coating layer in the same manner as described above.
Similar to the coated tools 49 to 58 of the present invention, the comparative coated tools 49 to 58 are formed with the lower layer shown in Table 27 and / or the upper layer shown in Table 29 under the forming conditions shown in Table 18. 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 same average layer thickness as the target layer thicknesses shown in Tables 27 to 29.
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 28 and Table 29.

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 28 and Table 29.

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: 440 m / min,
Incision: 1.5mm,
Feed: 0.2mm / 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: 420 m / min,
Cutting depth: 1.0 mm,
Feed: 0.2mm / rev,
Cutting time: 5 minutes
(Normal cutting speed is 250 m / min),
Table 30 shows the results of the cutting test.

From the results shown in Tables 24 and 30, 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. , There is a predetermined in-grain average orientation difference, and by increasing the ratio of {100} orientation on the surface side from the tool substrate side, the hardness is improved due to the distortion of the crystal grains, and high wear resistance is achieved. While maintaining, toughness 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.

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.

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

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 Cr 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 compound nitride of at least one element selected from Cr) or a composite carbonitride layer,
(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. Analyzing and obtaining the average orientation difference within each crystal grain When the average orientation difference within the crystal grain is 2 degrees or more, the crystal grains are in an area ratio relative to the total area of the composite nitride or composite carbonitride layer. 20% or more
(D) Further, the inclination angle formed by the normal line of the {100} plane which is the crystal plane with respect to the normal direction of the surface of the tool base 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 Cr and Al, the composition of which is
Composition formula: (Cr 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 amount of Cr and Al in Al and the average content ratio y avg in the total amount of C and N in C (where x 2. The surface-coated cutting according to claim 1, wherein avg and y avg are both atomic ratios) satisfying 0.70 ≦ 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.
4. 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 any one of the above.
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. The surface-coated cutting tool according to any one of claims 1 to 4, 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 5, wherein a lower layer is formed of the Ti compound layer and has a total average layer thickness of 0.1 to 20 µm.
7. The 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 claim 1.
8. The composite nitride or composite carbonitride layer is formed by chemical vapor deposition containing at least trimethylaluminum as a reactive gas component, according to any one of claims 1 to 7. A method of manufacturing a surface-coated cutting tool.