JP2021167057A - Cutting tool and manufacturing method for the same - Google Patents

Abstract

To provide a cutting tool having excellent tolerability against initial abrasion and abrasion by heat, and a manufacturing method for the same.SOLUTION: A cutting tool comprises a base material and a coating layer arranged on the base material, where the coating layer is constituted of cubic hard particles. The cubic hard particle is constituted of a multilayer structure part and a matrix-domain structure part. The multilayer structure part is in contact with the matrix-domain structure part, at the opposite side of the base material, and the multilayer structure part includes a first unit layer and a second unit layer. The matrix-domain structure part includes a matrix region and a domain region surrounded by the matrix region. The cubic hard particle is made of nitride or carbide including aluminium and titanium as constituent elements. An atom ratio x of the aluminium is 0.7 or more and 0.96 or less with respect to a total of the aluminium and the titanium in the cubic hard particle as a reference. When the coating layer is analyzed by an X-ray diffraction method, peak intensity derived from an orientation (111) shows a maximum value in comparison with peak intensity derived from other orientations.SELECTED DRAWING: None

Description

The present disclosure relates to a cutting tool and a method for manufacturing the same.

Conventionally, cutting of steel, castings, etc. has been performed using a cutting tool made of cemented carbide. Since the cutting edge of such a cutting tool is exposed to a harsh environment such as high temperature and high stress during cutting, wear and chipping of the cutting edge are caused.

Therefore, it is important to suppress wear and chipping of the cutting edge in order to improve the life of the cutting tool. For the purpose of improving the cutting performance of cutting tools, the development of a coating film that covers the surface of a base material such as cemented carbide is underway. Among them, a film made of a compound of aluminum (Al), titanium (Ti) and nitrogen (N) (hereinafter, also referred to as "AlTiN") can have high hardness and increase the Al content ratio. This makes it possible to increase the oxidation resistance.

For example, Japanese Patent Application Laid-Open No. 2008-54563 (Patent Document 1) describes an object coated with a hard film having a single-layer or multi-layer structure, and the layer structure is created by CVD without performing plasma excitation. It _{has at least one Ti 1-x} Al _x N hard film, and the Ti _1-x Al _x N hard film has a stoichiometric coefficient of x> 0.75-x = 0.93 and 0.412 nm to 0. or is present as a layer of single phase cubic NaCl structure with lattice constants _{a fcc} of .405nm or the _{Ti 1-x} Al x N hard coating, is its major phase x> 0.75~x = _{It consists of Ti 1-x} Al _x N having a cubic NaCl structure with a stoichiometric coefficient of 0.93 and a lattice constant a _{fcc of 0.412 nm to 0.405 nm, and Ti 1-x} Al _x as another phase. It is a polyphase layer in which N is contained as a wurtzite structure and / or _{as TiN x of a NaCl structure, and the chlorine content of the Ti 1-x} Al _x N hard film is 0.05 to 0.9. Hard film coated objects, in the atomic% range, are disclosed.

Japanese Patent Application Laid-Open No. 2014-129562 (Patent Document 2) describes a surface coating member containing a base material and a hard coating formed on the surface of the base material, and the hard coating is composed of one or more layers. At least one of the layers is a layer containing hard particles, and the hard particles include a multilayer structure in which first unit layers and second unit layers are alternately laminated, and the first unit layer is , One or more elements selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements and Al in the periodic table, and one or more elements selected from the group consisting of B, C, N and O. The second unit layer contains one or more elements selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements and Al in the periodic table, and B, C, N and O. A surface covering member containing a second compound consisting of one or more elements selected from the group consisting of is disclosed.

International Publication No. 2018/158975 (Patent Document 3) is a surface coating cutting tool including a base material and a coating film formed on the surface thereof, wherein the coating film contains one or more layers. At least one of the layers is an Al-rich layer containing hard particles, and the hard particles have a sodium chloride-type crystal structure and are between a plurality of massive first unit phases and the first unit phase. The first unit phase is _{composed of a nitride or carbonitride of Al x} Ti _1-x , and the atomic ratio x of Al of the first unit phase is 0.7. The second unit phase is 0.96 or less, the second unit phase is made of an Al _y Ti _1-y nitride or a carbonitride, and the atomic ratio y of Al in the second unit phase is more than 0.5 and 0. A surface-coated cutting tool that is less than .7 and shows the maximum peak on the (111) plane when the Al-rich layer is analyzed from the normal direction of the surface of the coating film using the X-ray diffraction method is disclosed. There is.

Japanese Patent Application Laid-Open No. 2008-54563 Japanese Unexamined Patent Publication No. 2014-129562 International Publication No. 2018/158975

In recent years, more efficient cutting (higher feed rate) is required, and further improvement in performance (for example, suppression of chipping and wear of the cutting edge) is expected. Further, it is required to develop a cutting tool suitable for the material of the work material.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a cutting tool having excellent resistance to initial wear and thermal wear, and a method for manufacturing the same.

The cutting tool according to the present disclosure is
A cutting tool including a base material and a coating layer arranged on the base material.
The coating layer is composed of cubic hard particles.
The cubic hard particles are composed of a multilayer structure and a matrix-domain structure.
The multilayer structure is in contact with the matrix-domain structure on the side opposite to the base material.
The multilayer structure portion includes a first unit layer and a second unit layer.
The matrix-domain structure portion includes a matrix region and a domain region surrounded by the matrix region.
The cubic hard particles are composed of nitrides or carbides containing aluminum and titanium as constituent elements.
The atomic ratio x of the aluminum is 0.7 or more and 0.96 or less based on the whole of the aluminum and the titanium in the cubic hard particles.
When the coating layer is analyzed by the X-ray diffraction method, the peak intensity derived from (111) orientation shows the maximum value as compared with the peak intensity derived from other orientations.

The method for manufacturing a cutting tool according to the present disclosure is as follows.
This is the manufacturing method of the above cutting tool.
The first step of preparing the above base material and
The second step of forming the precursor of the coating layer on the base material by using the chemical vapor deposition method, and
The third step of intermittently irradiating the surface of the precursor of the coating layer with energy particles, and
including.

According to the present disclosure, it becomes possible to provide a cutting tool having excellent resistance to initial wear and thermal wear and a method for manufacturing the same.

FIG. 1 is a perspective view illustrating one aspect of a base material of a cutting tool. FIG. 2 is a schematic cross-sectional view of a cutting tool according to one embodiment of the present embodiment. FIG. 3 is a schematic cross-sectional view of a cutting tool according to another aspect of the present embodiment. FIG. 4 is a schematic enlarged view of the coating layer of the cutting tool according to the present embodiment. FIG. 5 is a schematic view of hard particles in the coating layer according to the present embodiment. FIG. 6 is a photograph of a transmission electron microscope and an X-ray diffraction pattern (lower right) of the multilayer structure portion of the hard particles according to the present embodiment. FIG. 7 is a photograph of a transmission electron microscope and an X-ray diffraction pattern of the matrix-domain structure portion of the hard particles according to the present embodiment (lower right). FIG. 8 is a schematic cross-sectional view of a CVD apparatus used for manufacturing a cutting tool according to the present embodiment. FIG. 9 is a graph showing the correlation between the cutting time and the amount of wear on the flank in the examples.

[Explanation of Embodiments of the present disclosure]
First, the contents of one aspect of the present disclosure will be listed and described.
[1] The cutting tool according to the present disclosure is
A cutting tool including a base material and a coating layer arranged on the base material.
The coating layer is composed of cubic hard particles.
The cubic hard particles are composed of a multilayer structure and a matrix-domain structure.
The multilayer structure is in contact with the matrix-domain structure on the side opposite to the base material.
The multilayer structure portion includes a first unit layer and a second unit layer.
The matrix-domain structure portion includes a matrix region and a domain region surrounded by the matrix region.
The cubic hard particles are composed of nitrides or carbides containing aluminum and titanium as constituent elements.
The atomic ratio x of the aluminum is 0.7 or more and 0.96 or less based on the whole of the aluminum and the titanium in the cubic hard particles.
When the coating layer is analyzed by the X-ray diffraction method, the peak intensity derived from (111) orientation shows the maximum value as compared with the peak intensity derived from other orientations.

By providing the above-mentioned structure, the cutting tool can have excellent resistance to initial wear and thermal wear. The above-mentioned cutting tool is particularly suitable for cutting a work material made of alloy steel. Here, the "initial wear" means the wear that occurs at the start of cutting. "Thermal wear" means wear at high temperatures.

[2] When the coating layer contains hexagonal hard particles, the content ratio of the hexagonal hard particles is based on the total amount of the cubic hard particles and the hexagonal hard particles. When this is done, it is preferably more than 0% by volume and 20% by volume or less. By defining in this way, the cutting tool is more excellent against initial wear and thermal wear.

[3] The thickness of the matrix-domain structure is preferably 0.1 μm or more and 2 μm or less. By defining in this way, the cutting tool has more excellent resistance to initial wear.

[4] The cutting tool manufacturing method according to the present disclosure is the above-mentioned cutting tool manufacturing method.
The first step of preparing the above base material and
The second step of forming the precursor of the coating layer on the base material by using the chemical vapor deposition method, and
The third step of intermittently irradiating the surface of the precursor of the coating layer with energy particles, and
including.
By providing the above-mentioned configuration in the cutting tool manufacturing method, it is possible to manufacture a cutting tool having excellent resistance to initial wear and thermal wear. The above-mentioned method for manufacturing a cutting tool makes it possible to manufacture a cutting tool particularly suitable for cutting a work material made of alloy steel.

[5] In the second step, the first gas containing the aluminum halide gas and the titanium halide gas and the second gas containing ammonia gas are each at 650 ° C. or higher and 850 ° C. or lower and 0.5 kPa or higher. It is preferable to include spraying on the base material under the condition of 3.5 kPa or less. By defining in this way, it becomes possible to manufacture a cutting tool having excellent heat resistance.

[6] The energy particles in the third step are preferably gallium ions. By defining in this way, it becomes possible to manufacture a cutting tool having further excellent resistance to initial wear.

[Details of Embodiments of the present disclosure]
Hereinafter, one embodiment of the present disclosure (hereinafter referred to as “the present embodiment”) will be described. However, this embodiment is not limited to this. In the drawings used in the following embodiments, the same reference numerals represent the same parts or corresponding parts. In the present specification, the notation in the form of "A to Z" means the upper and lower limits of the range (that is, A or more and Z or less), and when there is no description of the unit in A and the unit is described only in Z, A The unit of and the unit of Z are the same. Further, in the present specification, when the compound is represented by a chemical formula such as "TiN" in which the composition ratio of the constituent elements is not limited, the chemical formula is any conventionally known composition ratio (element ratio). Shall include. At this time, the above chemical formula shall include not only the stoichiometric composition but also the non-stoichiometric composition. For example, the chemical formula of "TiN" includes not only the _{stoichiometric composition "Ti 1} N ₁ " but also a non-stoichiometric composition such as _{"Ti 1} N _0.8". This also applies to the description of compounds other than "TiN".

≪Cutting tool≫
The cutting tool according to this embodiment is
A cutting tool including a base material and a coating layer arranged on the base material.
The coating layer is composed of cubic hard particles.
The cubic hard particles are composed of a multilayer structure and a matrix-domain structure.
The multilayer structure is in contact with the matrix-domain structure on the side opposite to the base material.
The multilayer structure portion includes a first unit layer and a second unit layer.
The matrix-domain structure portion includes a matrix region and a domain region surrounded by the matrix region.
The cubic hard particles are composed of nitrides or carbides containing aluminum and titanium as constituent elements.
The atomic ratio x of the aluminum is 0.7 or more and 0.96 or less based on the whole of the aluminum and the titanium in the cubic hard particles.
When the coating layer is analyzed by the X-ray diffraction method, the peak intensity derived from (111) orientation shows the maximum value as compared with the peak intensity derived from other orientations.

The cutting tool 50 of the present embodiment includes a base material 10 and a coating layer 20 provided on the base material 10 (hereinafter, may be simply referred to as a “cutting tool”) (FIG. 2). In addition to the coating layer 20, the cutting tool 50 may further include a base layer 21 provided between the base material 10 and the coating layer 20 (FIG. 3). The base layer 21 will be described later.
In addition, each of the above-mentioned layers provided on the base material 10 may be collectively referred to as a "coating". That is, the cutting tool 50 includes a coating film 40 provided on the base material 10, and the coating film 40 includes the coating layer 20. Further, the coating film 40 may further include the underlying layer 21. In one aspect of the present embodiment, the coating film may cover the rake face of the base material, or may cover a portion other than the rake face (for example, a flank surface).

The above-mentioned cutting tools include, for example, drills, end mills, replaceable cutting tips for drills, replaceable cutting tips for end mills, replaceable cutting tips for milling, replaceable cutting tips for turning, metal saws, and gear cutting tools. , Reamer, tap, etc.

<Base material>
As the base material of the present embodiment, any base material can be used as long as it is conventionally known as a base material of this type. For example, the base material is a cemented carbide (for example, a cemented carbide (WC) -based cemented carbide, a cemented carbide containing Co in addition to WC, and a carbide such as Cr, Ti, Ta, Nb in addition to WC. Cemented carbide, etc.), cermet (mainly composed of TiC, TiN, TiCN, etc.), high-speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, etc.), cubic crystal It is preferable to contain at least one selected from the group consisting of a type boron nitride sintered body (cBN sintered body) and a diamond sintered body, and at least one selected from the group consisting of cemented carbide, cermet and cBN sintered body. More preferably, it contains seeds.

Among these various base materials, it is particularly preferable to select a WC-based cemented carbide or a cBN sintered body. The reason is that these base materials have an excellent balance between hardness and strength particularly at high temperatures, and have excellent characteristics as base materials for cutting tools for the above-mentioned applications.

When a cemented carbide is used as a base material, the effect of the present embodiment is exhibited even if such a cemented carbide contains an abnormal phase called a free carbon or η phase in the structure. The base material used in the present embodiment may have a modified surface. For example, in the case of cemented carbide, a deβ layer may be formed on the surface thereof, or in the case of a cBN sintered body, a surface hardened layer may be formed, and even if the surface is modified in this way. The effect of this embodiment is shown.

FIG. 1 is a perspective view illustrating one aspect of a base material of a cutting tool. A base material having such a shape is used, for example, as a base material for a cutting tip with a replaceable cutting edge for turning. The base material 10 has a rake face 1, a flank surface 2, and a cutting edge ridge line portion 3 where the rake face 1 and the flank surface 2 intersect. That is, the rake face 1 and the flank surface 2 are surfaces that are connected with the cutting edge ridge line portion 3 interposed therebetween. The cutting edge ridge line portion 3 constitutes the cutting edge tip portion of the base material 10. The shape of such a base material 10 can also be grasped as the shape of the cutting tool.

When the cutting tool is a cutting tip with a replaceable cutting edge, the base material 10 includes a shape having a tip breaker and a shape not having a tip breaker. The shape of the cutting edge ridge line portion 3 is a combination of sharp edge (ridge where the rake face and flank surface intersect), honing (shape that gives a radius to the sharp edge), negative land (shape that is chamfered), honing and negative land. Any shape is included in the shapes.

The shape of the base material 10 and the names of the parts have been described above with reference to FIG. 1. However, in the cutting tool 50 according to the present embodiment, the shape corresponding to the base material 10 and the names of the parts are the same as described above. The term is used. That is, the cutting tool has a rake face, a flank surface, and a cutting edge ridge line portion connecting the rake face and the flank surface.

<Coating>
The coating film 40 according to the present embodiment includes a coating layer 20 provided on the base material 10 (see FIG. 2). The "coating" covers at least a part of the above-mentioned base material (for example, a rake surface that comes into contact with a work material during cutting), and thus has various characteristics such as chipping resistance, wear resistance, and peeling resistance in a cutting tool. It has the effect of improving. The coating is not limited to a part of the base material, but preferably covers the entire surface of the base material. However, even if a part of the base material is not coated with the coating film or the composition of the coating film is partially different, it does not deviate from the scope of the present embodiment.

The thickness of the coating film is preferably 4 μm or more and 30 μm or less, and more preferably 7 μm or more and 25 μm or less. Here, the thickness of the coating means the total thickness of each of the layers constituting the coating. Examples of the "layer constituting the coating film" include a coating layer and an underlayer, which will be described later. The thickness of the coating film is, for example, measured at any 10 points in a cross-sectional sample parallel to the normal direction of the surface of the base material using a transmission electron microscope (TEM), and the average of the measured thicknesses of the 10 points. It can be obtained by taking a value. The same applies to the case of measuring the thickness of each of the coating layer and the base layer, which will be described later. Examples of the scanning transmission electron microscope include JEM-2100F (trade name) manufactured by JEOL Ltd.

(Coating layer)
The coating layer in this embodiment is arranged on the base material. Here, "arranged on the base material" is not limited to the mode in which it is arranged directly above the base material (see FIG. 2), and is arranged on the base material via another layer. Aspects (see FIG. 3) are also included. That is, the coating layer may be arranged directly above the base material as long as the effects of the present disclosure are exhibited, or may be arranged on the base material via another layer such as a base layer described later. You may be. Further, the coating layer is the outermost surface of the coating.

The coating layer 20 is made of cubic hard particles 30 (FIG. 4). Here, "consisting of cubic hard particles" is not limited to an embodiment consisting of only cubic hard particles, and as long as the effects of the present disclosure are exhibited, cubic hard particles and cubic crystals are used. It is a concept including an aspect composed of hard particles other than the crystal type of the type. That is, in one aspect of the present embodiment, the coating layer may consist only of cubic hard particles. Further, the coating layer may be composed of cubic hard particles and hard particles other than the cubic crystal type. Examples of the "hard particles other than the cubic crystal type" include hexagonal hard particles. Cubic hard particles and hexagonal hard particles are distinguished by, for example, the pattern of diffraction peaks obtained by X-ray diffraction described below.

In one aspect of the present embodiment, the coating layer may contain an amorphous phase as long as the effects of the present disclosure are exhibited.

((111) Peak intensity derived from orientation)
In the present embodiment, when the coating layer is analyzed by the X-ray diffraction method, the peak intensity derived from (111) orientation shows the maximum value as compared with the peak intensity derived from other orientations. As a result, in the cutting tool, most of the hard particles contained in the coating layer are inclined by 45 ° with respect to the normal direction of the surface of the coating, and the normal line and the above-mentioned virtual line showing the inclination of 45 ° are obtained. It is understood that the crystal grows in a direction inclined by 45 ° in a direction perpendicular to the including virtual plane. Therefore, the cutting tool can have an effect of effectively suppressing initial wear as well as high hardness. Further, since it shows the maximum peak intensity on the (111) plane, it has a very high hardness and can be more excellent in wear resistance. Here, the "peak intensity derived from another orientation" includes a peak intensity derived from (200) orientation and a peak intensity derived from (220) orientation. Specifically, the following method is applied to the X-ray diffraction (XRD) method performed on the coating layer.

First, the cutting tool to be measured by the X-ray diffraction method can be analyzed by using an X-ray diffractometer (trade name: "SmartLab (registered trademark)", manufactured by Rigaku Co., Ltd.) from the normal direction of the surface of the coating. Set in the direction of

Next, the coating layer of the cutting tool is analyzed from the normal direction of the surface of the coating under the following conditions. As a result, data on the X-ray diffraction peak in the coating layer can be obtained.
Measurement method: ω / 2θ method Incident angle (ω): 2 °
Scan angle (2θ): 30-70 °
Scan speed: 1 ° / min
Scan step width: 0.05 °
X-ray source: Cu-Kα ray Optical system Attribute: Medium resolution parallel beam tube Voltage: 45 kV
Tube current: 200mA
X-ray irradiation range: Using a 2.0 mm range limiting collimator, irradiate a range with a diameter of 2 mm on the rake face (however, it is permissible to irradiate the flank with X-rays under the same conditions).
X-ray detector: Semiconductor detector (trade name: "D / teX Ultra250", manufactured by Rigaku Co., Ltd.)

Based on the total of (200) peak intensity derived from orientation, (111) peak intensity derived from orientation, and (220) peak intensity derived from orientation, the ratio of peak intensity derived from (111) orientation is 50. It is preferably% or more and 100% or less, and more preferably 55% or more and 90% or less. Here, the "peak intensity" means the height (cps) of the peak in the X-ray spectrum.

The thickness of the coating layer is preferably 4 μm or more and 30 μm or less, and more preferably 7 μm or more and 25 μm or less. The thickness of the coating layer can be confirmed by observing the vertical cross section of the base material and the coating film using a TEM in the same manner as described above. Hereinafter, the hard particles constituting the coating layer will be described.

(Cubic hard particles)
The cubic hard particles 30 according to the present embodiment include a multilayer structure portion 32 and a matrix-domain structure portion 31 (FIG. 5). The multilayer structure portion 32 is in contact with the matrix-domain structure portion 31 on the side opposite to the base material 10 (FIG. 5).

The cubic hard particles are made of a nitride or carbide containing aluminum and titanium as constituent elements. Examples of the nitride containing aluminum and titanium as constituent elements include compounds represented by _{Al x} Ti _{1-x N.} Here, the composition ratio (elemental ratio) of "Al _x Ti _1-x " and "N" in the chemical formula "Al _x Ti _1-x N" is a stoichiometric composition (for example, (Al _x Ti _1-x). ) _{Not only 1} N ₁ ) but also non-stoichiometric compositions (eg (Al _x Ti _1-x ) ₁ N _0.8 ) are included. Examples of carbonitrides containing aluminum and titanium as constituent elements include compounds represented by _{Al x} Ti _{1-x CN.} Here, the composition ratio (elemental ratio) of "Al _x Ti _1-x " and "CN" in the chemical formula "Al _x Ti _1-x CN" is a stoichiometric composition (for example, (Al _x Ti _1-x). ) ₁ (CN) ₁ ) as well as non-stoichiometric compositions (eg, (Al _x Ti _1-x ) ₁ (CN) _0.8 ).

The atomic ratio x of the aluminum (Al) is 0.7 or more and 0.96 or less, and 0.75 or more and 0.9 or less based on the whole of the aluminum and titanium in the cubic hard particles. Is preferable. The atomic ratio x is an energy dispersive X-ray spectroscopy (EDX) apparatus attached to a transmission electron microscope (TEM) for the cubic hard particles appearing in the cross-sectional sample. It can be obtained by analyzing using. The atomic ratio x of aluminum obtained at this time is a value obtained as the average of all the cubic hard particles. Specifically, the value of the atomic ratio of aluminum is obtained by measuring each of the 10 arbitrarily selected hard particles in the coating layer of the cross-sectional sample, and the average value of the obtained 10 points is the cube. The atomic ratio of aluminum in crystalline hard particles. At this time, a numerical value that seems to be an abnormal value at first glance shall not be adopted. Here, the "10 arbitrarily selected locations" are selected from hard particles different from each other in the coating layer. Examples of the EDX device include JED-2300 (trade name) manufactured by JEOL Ltd. Not only aluminum but also the atomic ratios of titanium, nitrogen, etc. can be calculated by the above method.

(Multi-layer structure)
The multilayer structure portion includes a first unit layer and a second unit layer. The first unit layer and the second unit layer are laminated alternately. In the present embodiment, the interface between the first unit layer and the second unit layer is perpendicular to or substantially perpendicular to the direction in which the first unit layer and the second unit layer are laminated. In other words, the first unit layer and the second unit layer do not form an interface that is not perpendicular to the direction in which both layers are laminated. Therefore, in the multilayer structure portion, the first unit layer is not surrounded by the second unit layer. Further, the second unit layer is not surrounded by the first unit layer. In other words, the first unit layer is surrounded by the second unit layer in the direction in which both layers are laminated, but the second unit layer is in the direction perpendicular to the direction in which both layers are laminated. It can be grasped that it is not surrounded by a unit layer. Further, the second unit layer is surrounded by the first unit layer in the direction in which both layers are laminated, but the first unit is in the direction perpendicular to the direction in which both layers are laminated. It can be grasped that it is not surrounded by layers. That is, the multilayer structure portion forms a structure clearly different from the matrix-domain structure portion described later.

(First unit layer)
The first unit layer is a layer having a higher atomic ratio of aluminum than the second unit layer described later. When the multilayer structure portion is observed by TEM, the first unit layer is observed as a darker layer as compared with the second unit layer (see, for example, FIG. 6). Therefore, the first unit layer can be clearly distinguished from the second unit layer.

The thickness of the first unit layer is preferably 1 nm or more and 20 nm or less, and more preferably 2 nm or more and 10 nm or less. The thickness of the first unit layer was measured by measuring 10 arbitrarily selected points in the same layer in a cross-sectional sample parallel to the normal direction of the surface of the base material using TEM, and the thickness of the measured 10 points. It can be obtained by taking the average value of. At this time, a numerical value that seems to be an abnormal value at first glance shall not be adopted. When the multilayer structure portion includes two or more first unit layers, the thickness of each first unit layer is first obtained by the above method, and the average value of the obtained values is calculated as the first unit layer in the multilayer structure portion. The thickness. When the number of the first unit layers contained in the multilayer structure portion exceeds 10, the thickness of each of the 10 first unit layers is obtained by the above method in the arbitrarily selected 10 first unit layers. The average value of the values obtained from each of the first unit layers is taken as the thickness of the first unit layer in the multilayer structure portion.

(Second unit layer)
The second unit layer is a layer having a lower atomic ratio of aluminum than the first unit layer. When the multilayer structure portion is observed by TEM, the second unit layer is observed as a brighter layer than the first unit layer (see, for example, FIG. 6). Therefore, the second unit layer can be clearly distinguished from the first unit layer.

The thickness of the second unit layer is preferably 0.5 nm or more and 5 nm or less, and more preferably 1 nm or more and 2.5 nm or less. The thickness of the second unit layer can be determined by using a TEM in the same manner as described above.

(Repeating unit of 1st unit layer and 2nd unit layer)
In the repeating unit composed of one layer of the first unit layer and one layer of the second unit layer, the thickness of the repeating unit is preferably 1.5 nm or more and 25 nm or less, and 1.5 nm or more and 20 nm or less. Is more preferable, and 5 nm or more and 15 nm or less is further preferable. The present inventors consider that the coating layer has improved resistance to thermal wear when the repeating unit has the above-mentioned structure. The multilayer structure portion according to the present embodiment is formed by alternately stacking the first unit layer and the second unit layer, but the first unit layer of one adjacent layer and the second layer of one layer are adjacent to each other. Together with the unit layer, it is referred to as a "repeating unit consisting of a first unit layer of one layer and a second unit layer of one layer" or simply a "repeating unit". The “thickness of the repeating unit” means the total of the thickness of the first unit layer and the thickness of the second unit layer constituting the repeating unit.

(Matrix-domain structure part)
The matrix-domain structure portion includes a matrix region and a domain region surrounded by the matrix region.

The thickness of the matrix-domain structure is preferably 0.1 μm or more and 2 μm or less, and more preferably 0.2 μm or more and 1.5 μm or less. The thickness d of the matrix-domain structure portion should be grasped as the shortest distance between the surface of the hard particles on the side opposite to the base material and the interface between the multilayer structure portion and the matrix-domain structure portion. (See Fig. 5). At this time, it is considered that the surface of the hard particles on the side opposite to the base material and the interface between the multilayer structure portion and the matrix-domain structure portion are conceptually parallel. Further, the above-mentioned interface is a unit layer (that is, a first unit layer or a second unit layer) farthest from the side of the base material in the multilayer structure portion, and is a unit layer in which a layered structure is maintained. It can also be grasped as the interface far from the base material. Specifically, TEM was used to measure 10 arbitrarily selected hard particles in the coating layer in a cross-sectional sample parallel to the normal direction of the surface of the substrate, and the measured 10 matrix. -It can be obtained by taking the average value of the thickness of the domain structure. At this time, a numerical value that seems to be an abnormal value at first glance shall not be adopted.

(Domain area)
In the present embodiment, the “domain region” means a region (for example, a region shown darkly in FIG. 7) which is divided into a plurality of portions and exists in a dispersed state in a matrix region described later. At this time, the domain region is considered to be dispersed in the matrix region in all directions. Here, "any direction" includes the normal direction of the surface of the base material and the direction perpendicular to the normal direction. The above-mentioned "distributed state" basically means that adjacent domain regions do not come into direct contact with each other, but does not exclude those in which some domain regions are in contact with each other.

Further, the domain region can be grasped as a region divided into a plurality of regions in the matrix-domain structure portion. In one aspect of the present embodiment, it can be grasped that most of the plurality of regions constituting the domain region are surrounded by the matrix region. At this time, it is considered that the domain region is surrounded by the matrix region in all directions. Here, "any direction" includes the normal direction of the surface of the base material and the direction perpendicular to the normal.

As described above, in the matrix-domain structure portion, the domain region is dispersed in the matrix region. Therefore, the domain region and the matrix region do not form a laminated structure, and the matrix-domain structure portion forms a structure clearly different from the multilayer structure portion.

The domain region is a region in which the atomic ratio of aluminum is higher than that of the matrix region described later. When the matrix-domain structure portion is observed by TEM, the domain region is observed as a dark region as compared with the matrix region (see, for example, FIG. 7). Therefore, the domain region can be clearly distinguished from the matrix region.

The volume ratio of the domain region is not particularly limited, but may be 50% by volume or more and 90% by volume or less, or 60% by volume or more and 85% by volume, based on the total product of the domain region and the matrix region. It may be as follows. The volume ratio of the domain region can be obtained as follows. First, a predetermined field of view (for example, 0.5 μm × 0.5 μm) in a cross-sectional sample parallel to the normal direction of the surface of the base material is observed by TEM to obtain an observation image. The magnification at this time is, for example, 2000000 times. In the obtained observation image, the areas of each of the domain region and the matrix region are calculated. Next, the area ratio of the domain region is calculated based on the total area of the domain region and the matrix region. Such measurements are performed in at least 10 visual fields, and the average value of the area ratios calculated in each of the 10 visual fields is treated as the volume ratio of the domain region.

The size of the domain region is preferably 2 nm or more and 15 nm or less, and more preferably 2.5 nm or more and 10 nm or less. The size of the domain area can be obtained as follows. First, a predetermined field of view (for example, 0.05 μm × 0.05 μm) in a cross-sectional sample parallel to the normal direction of the surface of the base material is observed by TEM to obtain an observation image. The magnification at this time is, for example, 10,000,000 times. In the obtained observation image, the area of each domain region is calculated, and the equivalent circle equivalent diameter (Heywood diameter) is obtained based on the calculated area. The number of domain regions to be measured at this time is at least 10 or more.

(Matrix area)
In the present embodiment, the “matrix region” is a region (for example, a region shown brightly in FIG. 7) that is a base of the matrix-domain structure portion, and means a region other than the domain region. In other words, most of the matrix region can be grasped as an region arranged so as to surround each of the plurality of regions constituting the domain region. It can also be understood that most of the matrix region is arranged between a plurality of regions constituting the domain region.

The matrix region is a region in which the atomic ratio of aluminum is lower than that of the domain region. The matrix region is observed as a bright region as compared with the domain region when the matrix-domain structure portion is observed by TEM (see, for example, FIG. 7). Therefore, the matrix region can be clearly distinguished from the domain region.

The volume ratio of the matrix region is not particularly limited, but may be 10% by volume or more and 50% by volume or less, or 10% by volume or more and 40% by volume, based on the total volume of the domain region and the matrix region. It may be 10% by volume or more and 30% by volume or less. The volume ratio of the matrix region can be obtained as follows. First, a predetermined field of view (for example, 0.5 μm × 0.5 μm) in a cross-sectional sample parallel to the normal direction of the surface of the base material is observed by TEM to obtain an observation image. The magnification at this time is, for example, 2000000 times. In the obtained observation image, the areas of each of the domain region and the matrix region are calculated. Next, the area ratio of the matrix region is calculated based on the total area of the domain region and the matrix region. Such measurements are performed in at least 10 visual fields, and the average value of the area ratios calculated in each of the 10 visual fields is treated as the volume ratio of the matrix region.

(Hexagonal hard particles)
As long as the effects of the present disclosure are exhibited, the coating layer may contain hexagonal hard particles. The constituent elements of the hexagonal hard particles are considered to be the same as the constituent elements of the cubic hard particles. However, the elemental composition of the hexagonal hard particles may be the same as or different from the elemental composition of the cubic hard particles. When the coating layer contains hexagonal hard particles, the content ratio (h / (c + h)) of the hexagonal hard particles is the cubic hard particles (c) and the hexagonal hard particles. Based on the total amount of the particles (h), it is preferably more than 0% by volume and 20% by volume or less, more preferably more than 0% by volume and 15% by volume or less, and 0% by volume. It is more preferably more than 10% by volume or less. In one aspect of this embodiment, it is preferable that the coating layer does not contain hexagonal hard particles. The content ratio can be obtained, for example, by analyzing the pattern of the diffraction peak obtained by X-ray diffraction. The specific method is as follows.

An X-ray diffractometer (“MiniFlex 600” (trade name) manufactured by Rigaku) is used to obtain an X-ray spectrum of the coating layer in the above-mentioned cross-sectional sample. The conditions of the X-ray diffractometer at this time are as follows, for example.
Characteristic X-ray: Cu-Kα (wavelength 1.54 Å)
Tube voltage: 45kV
Tube current: 40mA
Filter: Multi-layer mirror Optical system: Concentrated method X-ray diffraction method: θ-2θ method

In the obtained X-ray spectrum, the peak intensity (Ic) of the cubic hard particles and the peak intensity (Ih) of the hexagonal hard particles are measured. Here, the "peak intensity" means the height (cps) of the peak in the X-ray spectrum. The peaks of the cubic hard particles can be confirmed at the diffraction angles of 2θ = 38 ° and around 44 °. The peak of the hexagonal hard particles can be confirmed at a diffraction angle of 2θ = 33 °. The peak intensity shall be the value excluding the background.

The content ratio (volume%) of the hexagonal hard particles based on the total amount of the cubic hard particles and the hexagonal hard particles is calculated by the following formula. Here, the peak intensity (Ic) of the cubic hard particles is determined by the sum of the peak intensity near 2θ = 38 ° and the peak intensity near 2θ = 44 °.
Content ratio (volume%) of the hexagonal hard particles = 100 × {Ih / (Ih + Ic)}

(Other layers)
The coating may further contain other layers as long as the effects of the present embodiment are not impaired. The other layers may have a different composition from or the same as the coating layer. Other layers may include, for example, TiN layer, TiCN layer, TiBN layer, the _{the Al} 2 _{O 3} layer or the like. For example, examples of the other layer include a base layer provided between the base material and the hard coating layer. The thickness of the other layers is not particularly limited as long as the effects of the present embodiment are not impaired, and examples thereof include 0.1 μm and more and 2 μm or less.

≪Manufacturing method of cutting tool≫
The method for manufacturing a cutting tool according to this embodiment is
This is the manufacturing method of the above cutting tool.
The first step of preparing the above base material and
The second step of forming the precursor of the coating layer on the base material by using the chemical vapor deposition method, and
The third step of intermittently irradiating the surface of the precursor of the coating layer with energy particles, and
including.

<First step: Step to prepare the base material>
In this step, the above-mentioned base material is prepared. As the base material, any conventionally known base material of this type can be used as described above. For example, when the base material is made of cemented carbide, a raw material powder having a predetermined compounding composition (mass%) is uniformly mixed using a commercially available attritor, and then this mixed powder is uniformly mixed into a predetermined shape (for example,). , SEET13T3AGSN-G, CNMG120408, etc.) and then sintered in a predetermined sintering furnace at 1300 ° C. to 1500 ° C. for 1 to 2 hours to obtain the above-mentioned base material made of cemented carbide. can. Further, as the base material, a commercially available product may be used as it is. Examples of commercially available products include EH520 (trade name) manufactured by Sumitomo Electric Hardmetal Corp.

<Second step: A step of forming a precursor of the coating layer on the base material by using a chemical vapor deposition method>
In this step, a chemical vapor deposition method is used to form a precursor of the coating layer on the substrate. In the second step, the first gas containing the halogenated aluminum gas and the halogenated titanium gas and the second gas containing ammonia gas are each charged at 650 ° C. or higher and 850 ° C. or lower and 0.5 kPa or higher and 3.5 kPa or higher. It is preferable to include spraying onto the base material in the following atmosphere. This step can be performed, for example, by using the CVD apparatus described below.

(CVD equipment)
FIG. 8 shows a schematic cross-sectional view of an example of a CVD apparatus used for manufacturing the cutting tool of the embodiment. As shown in FIG. 8, the CVD apparatus 70 includes a plurality of base material setting jigs 71 for installing the base material 10 and a reaction vessel 72 made of heat-resistant alloy steel that covers the base material setting jig 71. ing. Further, a temperature control device 73 for controlling the temperature inside the reaction vessel 72 is provided around the reaction vessel 72.

In the reaction vessel 72, the first gas introduction pipe 74 and the second gas introduction pipe 75 joined adjacent to each other extend the space inside the reaction vessel 72 in the vertical direction and can rotate about the vertical direction. It is provided in. In the gas introduction pipe 76, the first gas introduced into the first gas introduction pipe 74 and the second gas introduced into the second gas introduction pipe 75 are not mixed inside the gas introduction pipe 76. There is. Further, in each part of the first gas introduction pipe 74 and the second gas introduction pipe 75, the gas flowing inside each of the first gas introduction pipe 74 and the second gas introduction pipe 75 is applied to the base material setting jig 71. A plurality of through holes are provided on the base material 10 installed in the above.

Further, the reaction vessel 72 is provided with a gas exhaust pipe 77 for exhausting the gas inside the reaction vessel 72 to the outside, and the gas inside the reaction vessel 72 passes through the gas exhaust pipe 77. The gas is discharged to the outside of the reaction vessel 72 from the gas exhaust port 78.

More specifically, the above-mentioned first gas and second gas are introduced into the first gas introduction pipe 74 and the second gas introduction pipe 75, respectively. At this time, the temperatures of the first gas and the second gas in each gas introduction pipe are not particularly limited as long as they are not liquefied. Next, the first step into the reaction vessel 72 having an atmosphere of 650 ° C. or higher and 850 ° C. or lower (preferably 730 ° C. or higher and 750 ° C. or lower) and 0.5 kPa or higher and 3.5 kPa or lower (preferably 1.5 kPa or higher and 3.0 kPa or lower). The first gas and the second gas are repeatedly ejected in this order. Since the gas introduction pipe 76 has a plurality of through holes, the introduced first gas and second gas are ejected into the reaction vessel 72 from different through holes. At this time, the gas introduction pipe 76 rotates around its axis at a rotation speed of, for example, 2 to 10 rpm, as indicated by the rotation arrow in FIG. As a result, the first gas and the second gas can be repeatedly ejected to the base material 10 in this order.

(First gas)
The first gas includes a halide gas of aluminum and a halide gas of titanium.

Examples of the aluminum halide gas include aluminum chloride gas (AlCl ₃ gas, Al ₂ Cl ₆ gas) and the like. Preferably, AlCl ₃ gas is used. The concentration (volume%) of the halide gas of aluminum is preferably 0.3% by volume or more and 1.5% by volume or less, preferably 0.6% by volume, based on the total volume of the first gas and the second gas. More preferably, it is 0.8% by volume or less.

Examples of the titanium halide gas include titanium (IV) chloride gas (TiCl ₄ gas) and titanium (III) chloride gas (TiCl ₃ gas). Titanium (IV) chloride gas is preferably used. The concentration (volume%) of the halide gas of titanium is preferably 0.1% by volume or more and 1% by volume or less, and 0.14% by volume or more and 0, based on the total volume of the first gas and the second gas. It is more preferably 4% by volume or less.

The volume ratio of the halide gas of aluminum in the mixed gas of the first gas and the second gas is 0.5 or more and 0.85 or less based on the total volume of the halide gas of aluminum and the halide gas of titanium. It is preferable, and it is more preferable that it is 0.6 or more and 0.85 or less.

The first gas may contain hydrogen gas or may contain an inert gas such as argon gas. The concentration (volume%) of the inert gas is preferably 5% by volume or more and 50% by volume or less, and is 20% by volume or more and 40% by volume or less, based on the total volume of the first gas and the second gas. Is more preferable. Hydrogen gas usually occupies the balance of the first gas and the second gas.

In one aspect of the present embodiment, the first gas may further contain a hydrocarbon gas. Examples of the hydrocarbon gas include methane gas and ethylene gas (C ₂ H ₄ gas). The concentration (volume%) of the hydrocarbon gas is preferably 0.1% by volume or more and 1% by volume or less, and 0.2% by volume or more and 0.4, based on the total volume of the first gas and the second gas. More preferably, it is less than or equal to the volume.

The flow rate of the first gas when ejected onto the base material is preferably 20 to 30 L / min.

(Second gas)
The second gas contains ammonia gas. Further, the second gas may contain hydrogen gas or may contain an inert gas such as argon gas. By ejecting the second gas onto the base material, the formation of the multilayer structure portion is promoted.

The concentration (volume%) of ammonia gas is preferably 0.5% by volume or more and 4% by volume or less based on the total volume of the first gas and the second gas, and is preferably 1% by volume or more and 2% by volume or less. Is more preferable. Hydrogen gas usually occupies the balance of the first gas and the second gas.

The flow rate of the second gas when ejected onto the base material is preferably 10 to 20 L / min.

<Third step: A step of intermittently irradiating the surface of the precursor of the coating layer with energy particles>
In this step, the surface of the precursor of the coating layer is intermittently irradiated with energy particles. By doing so, a part of the multilayer structure portion in the hard particles constituting the precursor of the coating layer is changed to the matrix-domain structure portion, thereby forming the coating layer. As is clear from the above steps, the multi-layer structure portion in the precursor of the coating layer and the multi-layer structure portion in the coating layer have the same layer structure and composition.

Conventionally, when converting a multilayer structure portion into a matrix-domain structure portion, it is necessary to heat-treat (anneal) the entire coating layer (that is, the entire hard particles). In such a conventional heat treatment, only hard particles composed entirely of a matrix-domain structure can be produced. In the present disclosure, it is possible to heat-treat only a part of the hard particles by intermittently irradiating the surface of the precursor of the coating layer with energy particles as described above. Therefore, it becomes possible to generate hard particles having both a multi-layer structure part and a matrix-domain structure part, and therefore, when cutting an alloy steel work material, it is excellent in initial wear and thermal wear. It becomes possible to provide a cutting tool having resistance.

It is considered that even with a cutting tool manufactured without performing the third step, the surface portion of the coating layer is eventually heated by the frictional heat associated with the cutting process. However, the present inventors consider that the matrix-domain structure is not formed because the degree of heating is not strictly controlled.

Examples of the energy particles include gallium ion (Ga ⁺ ) and xenon ion (Xe ⁺ ). In one aspect of the present embodiment, the energy particles in the third step are preferably gallium ions.

The method of irradiating the energy particles is not particularly limited, and examples thereof include laser treatment, electron beam irradiation, focused ion beam irradiation (FIB irradiation), and irradiation. As the apparatus, a known apparatus can be used, and examples thereof include JIB-4501 (trade name) manufactured by JEOL Ltd.

The time for irradiating the energy particles is preferably 0.01 seconds or more and 0.1 seconds or less, and more preferably 0.05 seconds or more and 0.1 seconds or less.

The waiting time (interval time) from irradiation with energy particles to the next irradiation is preferably 0.005 seconds or more and 0.02 seconds or less, preferably 0.01 seconds or more and 0.02 seconds or less. More preferably. By setting the time for irradiating the energy particles and the waiting time until the next irradiation as described above, heat can be efficiently applied to the surface of the precursor of the coating layer without escaping the heat to the base material. It will be possible.

The number of repetitions of the operation of irradiating the energy particles and waiting for a predetermined time is preferably 5 times or more and 500 times or less, and more preferably 10 times or more and 70 times or less.

In one aspect of the present embodiment, when FIB irradiation using gallium ions is performed as the third step, the following conditions are exemplified.
Acceleration voltage: 1-2 kV
Current density: 40-60nA
Irradiation angle: 45-90 °
Irradiation time: 0.1 seconds Interval: 0.02 seconds Number of repetitions: 10 to 50 times Processing depth: 250 to 1050 nm

<Other processes>
In the production method according to the present embodiment, in addition to the above-mentioned steps, a step of forming another layer, a step of surface treatment, and the like may be appropriately performed. When forming the other layer described above, the other layer may be formed by a conventional method.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

In this example, the sample Nos. 1-12 and sample No. 21-23 cutting tools were produced. After that, the performance of these cutting tools was evaluated. Sample No. 1 to 12 correspond to the examples. Sample No. 21 to 23 correspond to comparative examples.

≪Manufacturing of cutting tools≫
<Preparation of base material>
Sample No. 1-12 and sample No. In order to prepare the cutting tools of 21 to 23, the base material A having the composition shown in Table 1 below was prepared. Specifically, first, the raw material powder having the composition shown in Table 1 was uniformly mixed. Next, the mixed raw material powder was pressure-molded into a predetermined shape. Then, by sintering the above-mentioned pressure-molded raw material powder at a sintering temperature of 1300 to 1500 ° C. and a sintering time of 1 to 2 hours, a cemented carbide base material having a shape of SEET13T3AGS N-G (Sumitomo). Obtained (manufactured by Denko Hardmetal Co., Ltd.) (first step). SEET13T3AGS N-G has the shape of a cutting tip with a replaceable cutting edge for milling (for milling).

<Formation of coating>
A film was formed on the surface of the base material obtained above. Specifically, the base material 10 was set on the base material setting jig 71 using the CVD device 70 shown in FIG. 8, and the coating film 40 was formed on the base material 10 by using the CVD method.

(Formation of base layer)
Sample No. 1 to 12 and sample No. The conditions for forming the base layer in 21 and 22 are as shown in Table 2 below. In each sample, each layer of TiN, TiCN, and Al ₂ O ₃ was formed on the base material after adjusting the ejection time of the raw material gas so as to have the thickness shown in Table 6 described later. Sample No. For the base material of 23, a layer of AlTiN was formed on the base material by the PVD method (physical vapor deposition method) using a target composed of Al and Ti (target composition, Al: Ti = 50: 50).

Here, the PVD conditions when the AlTiN layer is formed on the base material of sample No. 23 are as follows.
Arc current: 150V
Bias voltage: -40A
Chamber pressure: 2.6 × 10 ^-3 Pa
Reaction gas: Nitrogen gas Rotation speed of the rotary table on which the base material is placed: 10 rpm

(Formation of coating layer)
Regarding the coating layer, a second step of forming a precursor of the coating layer on the substrate by using the chemical vapor deposition method (CVD method) described above, and energy particles on the surface of the precursor of the coating layer. Was formed by performing a third step of intermittently irradiating.

(Second step)
First, a precursor of a coating layer (a layer consisting of only the above-mentioned multilayer structure portion) was formed on the base material by the second step. As shown in Table 3, the conditions for forming the precursor of the coating layer were two conditions, T1 and T2. Under condition T1, a first gas containing _{AlCl 3} gas, TiCl ₄ gas and H _{2 gas and a second gas containing NH 3} gas and Ar gas were ejected, respectively, to form a mixed gas in the reaction vessel. Under the condition T2, in addition to AlCl ₃ gas, TiCl ₄ gas and H ₂ gas, a first gas containing _{C 2} H _{4 gas and a second gas containing NH 3} gas and Ar gas are ejected, respectively, in the reaction vessel. A mixed gas was formed in. Under the conditions T1 and T2, the composition of the mixed gas, _{the volume ratio of AlCl 3} / (AlCl ₃ + TiCl ₄ ) in the mixed gas, and the temperature and pressure conditions in the reaction vessel 72 of the CVD apparatus 70 are as shown in Table 3, respectively. be.

Specifically, in the second step, the first gas was introduced into the introduction pipe 76 from the introduction port 74 of the CVD apparatus 70, and the second gas was introduced into the introduction pipe 76 from the introduction port 75. Subsequently, the introduction pipe 76 was rotated to eject the first gas and the second gas from the through hole of the introduction pipe 76. As a result, a mixed gas in which the first gas and the second gas were homogenized was obtained, and the obtained mixed gas was ejected onto the base layer to form a precursor of the coating layer.

As shown in Table 3, for example, under condition T1, the first unit layer having an atomic ratio of aluminum of 0.80 and the second unit layer having an atomic ratio of aluminum of 0.55 have a repetition period (that is, repetition). It is laminated at a unit thickness of 6 nm to form a precursor of a coating layer in which the average composition of the first unit layer and the second unit layer (that is, the average composition of the multilayer structure portion) is Al _0.75 Ti _{0.25 N.} can do.

In the second step, as shown in Table 6 described later, the sample No. 1 to 7 and sample No. For the substrates 21 and 22, a precursor of the coating layer was formed using the condition T1. Sample No. For the substrates 8 to 12, a precursor of the coating layer was formed using the condition T2. Here, the sample No. A transmission electron microscope image of the multilayer structure portion in the precursor of the coating layer 1 is shown in FIG. A trade name: "JEM-2100F (manufactured by JEOL Ltd.)" was used for the transmission electron microscope.

(Third step)
Furthermore, sample No. For 1 to 12, a matrix-domain structure is generated by intermittently irradiating the surface of the precursor of the coating layer with gallium ions (energy particles) by the third step (FIB irradiation). A coating layer was obtained. As is clear from the above steps, it is considered that the multilayer structure portion in the precursor of the coating layer and the multilayer structure portion in the coating layer have the same layer structure and composition. As shown in Table 4, the conditions for generating the matrix-domain structure part were three conditions J1 to J3.

As shown in Table 4, for example, under condition J1, the surface of the precursor of the coating layer was intermittently irradiated with gallium ions at an acceleration voltage of 1 kV, a current density of 40 nA, an irradiation angle of 45 °, and a treatment depth of 250 nm. At this time, a cycle with an irradiation time of 0.1 seconds and an interval of 0.02 seconds was repeated 10 times. As a device for irradiating gallium ions, JIB-4501 (trade name) manufactured by JEOL Ltd. was used.

In the third step, as shown in Table 6 described later, the sample No. A coating layer was obtained by using the condition J1 for the precursor of the coating layer of 1. Sample No. 2 and sample No. A coating layer was obtained by using the condition J2 for the precursors of the coating layers 4 to 7. Sample No. 3 and sample No. A coating layer was obtained by using condition J3 for the precursors of the coating layers 8 to 12. Sample No. The third step was not performed on the precursor of the coating layer of 21. Sample No. By annealing the precursor of the coating layer 22 under the following condition C1 instead of performing the third step, the entire multilayer structure portion of the hard particles in the precursor of the coating layer becomes a domain-matrix structure portion. It was varied to give a coating layer. Sample No. The third step was not performed on the AlTiN layer formed by the PVD method of No. 23.
Annealing condition C1
Heating rate: 10 ° C / min Annealing temperature: 900 ° C
Annealing time: 60 minutes Annealing atmosphere: Ar gas cooling temperature: 40 ° C./min In-core pressure during cooling: 0.9 MPa

Sample No. The transmission electron microscope image of the domain-matrix structure part in the hard particles in the coating layer in No. 1 is shown in FIG. A trade name: "JEM-2100F (manufactured by JEOL Ltd.)" was used for the transmission electron microscope.

(surface treatment)
Furthermore, the sample No. For 4.5, 7, 9, 10 and 12, respectively, surface treatment by shot blasting was performed under the conditions shown in Table 5 to apply compressive stress to the coating film.

By forming a film on each substrate as described above, the sample No. 1-12 and sample No. 21-23 cutting tools were produced. Table 6 shows the composition of the base material and the coating film in each sample. In Table 6, for example, sample No. Reference numeral 1 denotes a cutting tool in which a TiN layer having a thickness of 1 μm is formed as a base layer directly above the base material A, and a coating layer (AlTiN) having a thickness of 5 μm is formed on the base layer. There is. Sample No. The cutting tool of No. 1 has a coating layer obtained by treating the precursor of the coating layer formed under the condition T1 under the condition J1. In the "underlayer" column of Table 6, "-" means that there is no layer having the corresponding composition. In the "Surface treatment" column of Table 6, "-" means that no surface treatment was performed.

≪Evaluation of cutting tools≫
<Measurement of film thickness>
The thickness of the coating film, etc. (that is, the thickness of the coating layer and the base layer) is determined by using a transmission electron microscope (TEM) (manufactured by JEOL Ltd., trade name: JEM-2100F) in the normal direction of the surface of the base material. It was obtained by measuring arbitrary 10 points in a cross-section sample parallel to the above and taking the average value of the thicknesses of the measured 10 points. The observation magnification at this time was 10,000 times. The results are shown in Table 6.

<Observation of coating layer>
((111) Peak intensity derived from orientation)
Sample No. 1 to 12 and sample No. For the cutting tools 21 to 23, the coating layer was first analyzed from the stacking direction of the coating by the X-ray diffraction method under the following measurement conditions, and it was investigated at which crystal plane the diffraction peak was maximized. Further, from the above measurement results, the ratio of the peak intensities derived from the (111) orientation was calculated by the above method. The results are shown in Table 7. From the results in Table 7, the sample No. It was found that the coating layers in the cutting tools 1 to 12 had the maximum diffraction peak in the (111) plane. For example, the lower right photograph in FIGS. 6 and 7 shows the sample No. The result of X-ray diffraction of the coating layer in 1 cutting tool is shown. As a result, the surface-coated cutting tools of Samples 1 to 12 are expected to have excellent wear resistance and to exhibit excellent performance for applications requiring intermittent processing such as alloy steel.
Measurement method: ω / 2θ method Incident angle (ω): 2 °
Scan angle (2θ): 30-70 °
Scan speed: 1 ° / min
Scan step width: 0.05 °
X-ray source: Cu-Kα ray Optical system Attribute: Medium resolution parallel beam tube Voltage: 45 kV
Tube current: 200mA
X-ray irradiation range: Using a 2.0 mm range limiting collimator, irradiate a range with a diameter of 2 mm on the rake face (however, it is permissible to irradiate the flank with X-rays under the same conditions).
X-ray detector: Semiconductor detector (trade name: "D / teX Ultra250", manufactured by Rigaku Co., Ltd.)

(Volume ratio of hexagonal hard particles)
Next, sample No. 1 to 12 and sample No. The peak intensities of cubic hard particles and the peak intensities of hexagonal hard particles in the coating layer were measured for each of 21 to 23 cutting tools by the X-ray diffraction method under the following measurement conditions. The volume ratio of the hexagonal hard particles was calculated based on each measured peak intensity. The results are shown in Table 7. By this X-ray diffraction measurement, the sample No. It was confirmed that the coating layer in the cutting tools 1 to 12 contained cubic hard particles.
X-ray diffractometer: "MiniFlex 600" manufactured by Rigaku (trade name)
Characteristic X-ray: Cu-Kα (wavelength 1.54 Å)
Tube voltage: 45kV
Tube current: 40mA
Filter: Multi-layer mirror Optical system: Concentrated method X-ray diffraction method: θ-2θ method

(Elemental analysis of coating layer)
Furthermore, the sample No. 1 to 12 and sample No. For each of the cutting tools 21 to 23, the coating layer was observed using the transmission microscope described above, and elemental analysis was performed with the EDX attached to the transmission microscope. As a result, the atomic ratio x of Al of the hard particles constituting the coating layer was determined. The results are shown in Table 7.

(Matrix-thickness of domain structure)
The thickness of the matrix-domain structure was measured and measured using TEM for 10 arbitrarily selected hard particles in the coating layer in a cross-sectional sample parallel to the normal direction of the surface of the substrate. It was obtained by taking the average value of the thickness of the matrix-domain structure portion of the location. The results are shown in Table 7. In the column of "thickness of matrix-domain structure" in Table 7, "-" means that there is no matrix-domain structure in the hard particles.

<Cutting test 1>
Next, sample No. 1 to 12 and sample No. A cutting test (wear resistance test) was performed on the cutting tools 21 to 23 under the following cutting conditions. Specifically, the sample No. 1 to 12 and sample No. For the cutting tools 21 to 23 (the shape is SEET13T3AGSN-G), the cutting possible time until the flank wear amount (Vb) became 0.30 mm was measured under the following cutting conditions. The results are shown in Table 7. It is shown that the longer the cutting tool can be cut, the longer the life of the cutting tool is because the initial wear and the thermal wear are suppressed.

<Cutting conditions>
Work material: SCM440 block material (alloy steel)
Cutter: WGC4160R (manufactured by Sumitomo Electric Hardmetal Co., Ltd.)
Peripheral speed: 300m / min
Feed rate: 0.4 mm / sec Cut amount: 1.5 mm
Cutting fluid: None

From Table 7, sample No. The cutting tools of 1 to 12 (Examples) are sample No. It was found that the life of the cutting tool was longer because the initial wear and thermal wear were suppressed as compared with the cutting tools of 21 to 23 (comparative example).

<Cutting test 2>
Next, sample No. 2 and sample No. A cutting test (wear resistance test) was performed on the cutting tools 21 to 23 under the following cutting conditions, and the correlation between the cutting time and the amount of wear on the flank was investigated. Specifically, the sample No. 2 and sample No. The cutting tools (shape: SEET13T3AGSN-G) of 21 to 23 were cut under the following cutting conditions, and the flank wear amount (Vb) at each cutting time was measured. The cutting test was completed when Vb exceeded 0.31 mm. The results are shown in Table 8 and FIG. In Table 8, "-" means that the amount of wear on the flank was not measured. In FIG. 9, the vertical axis represents the amount of wear (mm) on the flank, and the horizontal axis represents the cutting time (minutes).

<Cutting conditions>
Work material: SCM440 block material (alloy steel)
Cutter: WGC4160R (manufactured by Sumitomo Electric Hardmetal Co., Ltd.)
Peripheral speed: 300m / min
Feed rate: 0.4 mm / sec Cut amount: 1.5 mm
Cutting fluid: None

From the results of Table 8 and FIG. 9, the sample No. having a coating layer containing hard particles consisting only of the multilayer structure portion was found. It was found that with the cutting tool No. 21, the amount of flank wear 1 minute after the start of cutting was 0.07 mm, and the initial wear was large. Sample No. having a coating layer containing hard particles consisting only of a matrix-domain structure. It can be seen that the flank wear amount of the 22 cutting tools from the start of cutting to 9 minutes later is smaller than that of the other three cutting tools and is resistant to initial wear. However, it was found that the amount of flank wear increased from around 10 minutes after the start of cutting, and the thermal wear was large. Sample No. having a coating layer formed by the PVD method. It was found that with the 23 cutting tools, both initial wear and thermal wear were large.

On the other hand, the sample No. having a coating layer made of hard particles composed of a multilayer structure portion and a matrix-domain structure portion arranged in contact with the surface of the multilayer structure portion. In the cutting tool No. 2, the flank wear 1 minute after the start of cutting was the sample No. It was found that it was smaller than 21 and had excellent resistance to initial wear. Further, the cutting tool has a sample No. 1 from about 10 minutes after the start of cutting. It was found that the flank wear amount was smaller than that of the 22 cutting tools, and the resistance to thermal wear was also excellent.

Although the embodiments and examples of the present invention have been described above, it is planned from the beginning that the configurations of the above-described embodiments and the embodiments are appropriately combined.

The embodiments and examples disclosed this time should be considered as exemplary in all respects and not restrictive. The scope of the present invention is shown not by the above-described embodiments and examples but by the scope of claims, and is intended to include meaning equivalent to the scope of claims and all modifications within the scope.

1 Scooping surface 2 Escape surface 3 Cutting edge ridge 10 Base material 20 Coating layer 21 Base layer 30 Hard particles 31 Matrix-domain structure 32 Multi-layer structure 40 Coating 50 Cutting tool 70 CVD equipment 71 Base material setting jig 72 Reaction vessel 73 Temperature controller 74 1st gas introduction pipe 75 2nd gas introduction pipe 76 Gas introduction pipe 77 Gas exhaust pipe 78 Gas exhaust port d Matrix-domain structure thickness

Claims (6)

A cutting tool including a base material and a coating layer arranged on the base material.
The coating layer is composed of cubic hard particles.
The cubic hard particles consist of a multilayer structure and a matrix-domain structure.
The multilayer structure is in contact with the matrix-domain structure on the side opposite to the base material.
The multilayer structure includes a first unit layer and a second unit layer.
The matrix-domain structure includes a matrix region and a domain region surrounded by the matrix region.
The cubic hard particles consist of nitrides or carbides containing aluminum and titanium as constituent elements.
The atomic ratio x of the aluminum is 0.7 or more and 0.96 or less based on the whole of the aluminum and the titanium in the cubic hard particles.
A cutting tool in which when the coating layer is analyzed by an X-ray diffraction method, the peak intensity derived from (111) orientation shows the maximum value as compared with the peak intensity derived from other orientations. When the coating layer contains hexagonal hard particles, the content ratio of the hexagonal hard particles is based on the total amount of the cubic hard particles and the hexagonal hard particles. The cutting tool according to claim 1, wherein the cutting tool is more than 0% by volume and 20% by volume or less. The cutting tool according to claim 1 or 2, wherein the thickness of the matrix-domain structure portion is 0.1 μm or more and 2 μm or less. The method for manufacturing a cutting tool according to any one of claims 1 to 3.
The first step of preparing the base material and
A second step of forming a precursor of the coating layer on the substrate using a chemical vapor deposition method, and
The third step of intermittently irradiating the surface of the precursor of the coating layer with energy particles, and
How to make cutting tools, including. In the second step, the first gas containing the halide gas of aluminum and the halide gas of titanium and the second gas containing ammonia gas are each at 650 ° C. or higher and 850 ° C. or lower and 0.5 kPa or higher and 3.5 kPa or higher. The method for manufacturing a cutting tool according to claim 4, which comprises ejecting the substrate under the following conditions. The method for manufacturing a cutting tool according to claim 4 or 5, wherein the energy particles in the third step are gallium ions.

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