Coated tools

Abstract

A non-limiting example of a coated tool according to the present invention comprises a substrate and a coating film disposed on the substrate. The coating film comprises: an Al2O3 layer; and a surface layer located from a first surface of the Al2O3 layer facing away from the substrate to a second surface serving as the coating film surface. In the surface layer, a first erosion rate measured when a liquid A containing 3% by mass of amorphous Al2O3 particles with an average particle size of 1.1 to 1.3 μm dispersed in pure water impacts the surface layer is less than 0.1 μm / minute, and a second erosion rate measured when a liquid B containing 3% by mass of spherical Al2O3 particles with an average particle size of 2.8 to 3.2 μm dispersed in pure water impacts the surface layer is greater than 2.0 μm / minute.

Description

[0001] [Cross-reference to related applications]

[0002] This application claims the benefit of Japanese Patent Application No. 2020-057635, filed on March 27, 2020, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to coated cutting tools. Background Art

[0004] Coated cutting tools, which have a coating applied to a substrate such as cemented carbide, are used for cutting. Coatings are known that are formed by sequentially stacking a TiN layer, a TiCN layer, and an Al2O3 layer on the substrate. Furthermore, there is a technology that uses a TiN layer on top of the Al2O3 layer, allowing the TiN layer to be removed during use, making it easier to clearly identify the corners after use.

[0005] In addition, Japanese Patent Application Laid-Open No. 2017-221992 (Patent Document 1) describes that a TiN layer and a Ti-based film other than TiN are arranged on an Al 2 O 3 layer.

[0006] Nanjo Yoshiyasu, 4 others, "Study on the Evaluation of Mechanical Properties of Single-layer TiCN Films and Multilayer TiCN Films Based on Microslurry Jet Erosion (MSE)", Journal of Precision Engineering, 2018, 84(2), pp. 167-174 (Non-Patent Document 1) is a study on the evaluation of the mechanical properties of such coatings, evaluating TiN and TiCN layers using the MSE method. In Non-Patent Document 1, an experiment was conducted in which a slurry of amorphous (polygonal) alumina with a particle size of 8000 and pure water was projected onto the coating. Non-Patent Document 1 states that the smaller the erosion rate obtained by the MSE method, the better the mechanical properties of the coating.

[0007] International Publication No. 2017 / 163972 (Patent Document 2) describes evaluating the wear resistance of a hard coating using the MSE method using amorphous (polygonal) alumina particles with a particle size of 8000. Patent Document 2 states that the smaller the erosion rate obtained by the MSE method, the better the wear resistance of the hard coating. Summary of the Invention

[0008] A non-limiting example of a coated tool according to the present invention comprises a substrate and a coating film disposed on the substrate. The coating film comprises: an Al2O3 layer; and a surface layer located from a first surface of the Al2O3 layer facing away from the substrate to a second surface serving as the surface of the coating film. In the surface layer, a first erosion rate measured by impacting a liquid A containing 3% by mass of amorphous Al2O3 particles with an average particle size of 1.1 to 1.3 μm in pure water is 0.1 μm / minute or less, and a second erosion rate measured by impacting a liquid B containing 3% by mass of spherical Al2O3 particles with an average particle size of 2.8 to 3.2 μm in pure water is 2.0 μm / minute or greater. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a perspective view showing a coated cutting tool according to a non-limiting embodiment of the present invention.

[0010] Figure 2 yes Figure 1 The cross-sectional view of the coated tool is shown at section II-II.

[0011] Figure 3 yes Figure 2 An enlarged view of the coating film of a coated tool is shown.

[0012] Figure 4 It is a perspective view showing a cutting tool according to a non-limiting embodiment of the present invention. DETAILED DESCRIPTION

[0013] <Coated tools>

[0014] A coated tool 1 according to a non-limiting embodiment of the present invention will be described in detail below using the accompanying drawings. However, for ease of explanation, the following figures illustrate only the essential components necessary to illustrate the embodiment. Therefore, the coated tool 1 may include any components not shown in the accompanying drawings. Furthermore, the component dimensions in the drawings do not accurately reflect the actual dimensions of the components or the dimensional ratios of the components.

[0015] exist Figures 1 to 3 In the figure, as an example of a coated tool 1, a cutting insert suitable for use in a cutting tool used to cut a workpiece is shown. In addition to cutting tools, the coated tool 1 can also be used for wear-resistant parts such as sliding parts and molds, tools such as excavators and knives, and impact-resistant parts. The applications of the coated tool 1 are not limited to the examples shown.

[0016] The coated tool 1 comprises a substrate 2 and a coating film 3 located on the substrate 2 .

[0017] Examples of materials for the substrate 2 include cemented carbide, ceramics, and metals. Examples of cemented carbide include a binder phase composed of ferrous metals such as Co (cobalt) and Ni (nickel), and a cemented carbide formed by combining WC (tungsten carbide) and at least one carbide selected from the group of carbides, nitrides, and carbonitrides of metals in Groups 4, 5, and 6 of the periodic table other than WC as needed. Examples of other cemented carbides include Ti-based cermets. Examples of ceramics include Si3N4 (silicon nitride), Al2O3 (aluminum oxide), diamond, and cBN (cubic boron nitride). Examples of metals include carbon steel, high-speed steel, and alloy steel. The material of the substrate 2 is not limited to the examples given.

[0018] The coating layer 3 may cover the entire surface 4 of the substrate 2 or only a portion thereof. When the coating layer 3 covers only a portion of the surface 4 of the substrate 2, it may also be referred to as the coating layer 3 being located at least partially on the substrate 2.

[0019] The coating layer 3 can be formed by chemical vapor deposition (CVD). In other words, the coating layer 3 can be a CVD film.

[0020] The coating 3 is not limited to a specific thickness. For example, the thickness of the coating 3 can be set to 1 to 30 μm. Furthermore, the thickness, structure, and crystal shape of the coating 3 can be measured, for example, by cross-sectional observation using an electron microscope. Examples of electron microscopes include scanning electron microscopes (SEMs) and transmission electron microscopes (TEMs).

[0021] Coated tool 1, such as Figure 1 and Figure 2 In the non-limiting example shown, the device may include: a first surface 5 (upper surface); a second surface 6 (side surface) adjacent to the first surface 5 ; and a blade 7 located at at least a portion of a ridge between the first surface 5 and the second surface 6 .

[0022] The first surface 5 may be a rake face. The entire first surface 5 may be a rake face, or a portion thereof may be a rake face. For example, the area along the cutting edge 7 of the first surface 5 may be a rake face.

[0023] The second surface 6 may be a flank surface. The entire second surface 6 may be a flank surface, or a portion thereof may be a flank surface. For example, the area along the blade 7 in the second surface 6 may be a flank surface.

[0024] The blade 7 may be located at a portion of the ridge portion or may be located at the entire ridge portion. The blade 7 may be used for cutting a workpiece.

[0025] Coated tool 1, such as Figure 1The non-limiting example shown is a quadrilateral plate. Furthermore, the shape of the coated tool 1 is not limited to a quadrilateral plate. For example, the first surface 5 may also be triangular, pentagonal, hexagonal, or circular. Furthermore, the coated tool 1 may also be cylindrical.

[0026] The coated tool 1 is not limited to a specific size. For example, the length of one side of the first surface 5 can be set to about 3 to 20 mm. In addition, the height from the first surface 5 to the surface (lower surface) opposite to the first surface 5 can be set to about 5 to 20 mm.

[0027] Here, the coating 3 is as Figure 3 The non-limiting example shown may include an Al 2 O 3 layer 8 and a surface layer 9 .

[0028] The Al2O3 layer 8 may contain Al2O3 particles. The Al2O3 layer 8 refers to a layer containing Al2O3 as a main component. The term "main component" may refer to a component that has the largest mass % value compared to other components.

[0029] The surface layer 9 may be located from the first surface 10 of the Al2O3 layer 8 on the side away from the substrate 2 to the second surface 11 as the surface of the coating film 3. In addition, the surface layer 9 may have the second surface 11. In addition, the surface layer 9 may be in contact with the Al2O3 layer 8.

[0030] The erosion rate of the surface layer 9 can be obtained by the MSE (Micro Slurry-jet Erosion) test. In the MSE test, amorphous Al2O3 particles and spherical Al2O3 particles can be used.

[0031] Amorphous Al2O3 particles can be produced by crushing raw material particles, etc. In addition, the crushing process can form broken surfaces and corners. Amorphous Al2O3 particles can also be referred to as angular Al2O3 particles.

[0032] Spherical Al2O3 particles have no corners and can be close to a spherical shape. In addition, the shape of the spherical Al2O3 particles does not need to be a spherical shape, as long as there are no broken surfaces and corners, some deformation is allowed.

[0033] The wear resistance of the surface layer 9 can be evaluated using the results of the MSE test using amorphous Al2O3 particles. Hereinafter, the erosion rate obtained by the MSE test using amorphous Al2O3 particles is referred to as the first erosion rate. A lower first erosion rate indicates superior wear resistance.

[0034] Furthermore, the peeling resistance of the surface layer 9 can be evaluated using the results of an MSE test using spherical Al2O3 particles. The erosion rate obtained from the MSE test using spherical Al2O3 particles is hereinafter referred to as the second erosion rate. A lower second erosion rate indicates excellent peeling resistance. In other words, a higher second erosion rate indicates increased peeling.

[0035] The first erosion rate can be 0.1 μm / minute or less, and the second erosion rate can be 2.0 μm / minute or more. In this case, the wear resistance is excellent. In addition, the surface of the coating 3 is easily peeled off. By making the surface of the coating 3 easily peeled off, the entire film is prevented from being destroyed due to a large impact, resulting in excellent fracture resistance. Specifically, when the first erosion rate is 0.1 μm / minute or less, the wear resistance is excellent. In addition, when the second erosion rate is 2.0 μm / minute or more, the surface layer 9 is easily peeled off from the Al2O3 layer 8. That is, the surface of the coating 3 is easily peeled off. Therefore, it is easy to make the used corners (blade 7) and the like clear. In addition, the fracture resistance is excellent.

[0036] The first erosion rate can be obtained by causing liquid A containing 3% by mass of amorphous Al2O3 particles with an average particle size of 1.1 to 1.3 μm dispersed in 100% by mass of pure water to impact the test object (surface layer 9) and evaluating the depth of the test object removed thereby.

[0037] Alternatively, the second erosion rate may be achieved by causing Liquid B, containing 3% by mass of spherical Al₂O₃ particles with an average particle size of 2.8 to 3.2 μm dispersed in 100% by mass of pure water, to impact the specimen and evaluate the depth of the specimen removed thereby. Furthermore, the average particle size of the spherical Al₂O₃ particles may be 2.9 to 3.1 μm.

[0038] When measuring the first erosion rate and the second erosion rate, liquid A or B may be brought into contact with the surface of the object (surface layer 9) at approximately right angles and impacted at a speed of 98 to 102 m / s.

[0039] The erosion rate can be measured using the MSE testing machine "MSE-Al2O3" manufactured by Palmeso Co., Ltd. Amorphous Al2O3 particles, for example, can be tested using the "MSE-GA-1-3" manufactured by Palmeso. Spherical Al2O3 particles, for example, can be tested using the "MSE-BA-3-3-10" manufactured by Palmeso. The average particle size of amorphous and spherical Al2O3 particles can be obtained by image processing of SEM photographs.

[0040] The first erosion rate may be 0.05 μm / min or less. Alternatively, the first erosion rate may be 0.01 μm / min or less. The second erosion rate may be 5.0 μm / min or more. Alternatively, the second erosion rate may be 3.0 μm / min or more.

[0041] The Al2O3 layer 8 may or may not be in contact with the substrate 2. For example, another layer may be located between the Al2O3 layer 8 and the substrate 2. In other words, the coating film 3 may have another layer located between the Al2O3 layer 8 and the substrate 2.

[0042] The surface layer 9 may include a TiN film. The surface layer 9 including the TiN film is easily peeled off.

[0043] Alternatively, the TiN film may be in contact with the Al2O3 layer 8. If the TiN film is in contact with the Al2O3 layer 8, the TiN film is easily peeled off from the Al2O3 layer 8. However, if the coating 3 is composed only of the TiN film, it is easy to peel off but has poor wear resistance.

[0044] A TiN film may contain TiN particles. A TiN film may be defined as a film containing TiN as a main component. This definition also applies to other films.

[0045] The surface layer 9 may include a TiC film. The surface layer 9 (coating film 3) including the TiC film has excellent wear resistance.

[0046] Furthermore, the TiC film does not need to be in contact with the Al2O3 layer 8. If the TiC film is in contact with the Al2O3 layer 8, the adhesion between the Al2O3 layer 8 and the TiC film will be too high, making it difficult to peel the surface layer 9. Therefore, at least one other film may be provided between the Al2O3 layer 8 and the TiC film. In other words, the surface layer 9 includes the TiC film and at least one other film located between the TiC film and the Al2O3 layer 8. For example, a TiN film is located between the Al2O3 layer 8 and the TiC film.

[0047] The surface layer 9 may include a TiCN film. The TiCN film may have properties substantially between those of a TiN film and a TiC film, that is, adhesion and wear resistance intermediate between those of TiN and TiC.

[0048] For example, when the Al2O3 layer 8 is in contact with the TiCN film, it is basically more difficult to peel off than when the Al2O3 layer 8 is not in contact with the TiCN film. Therefore, when the Al2O3 layer 8 is in contact with the TiCN film, an easily peelable TiCN film is required to ensure that the structure of the coated tool 1 is sufficient.

[0049] For example, if the N (nitrogen) content in a TiCN film is high, the TiCN film is easily peeled. To achieve an easily peelable TiCN film, the N / (C+N) ratio of the TiCN film can be 0.7 or greater. To produce a TiCN film with an N / (C+N) ratio of 0.7 or greater, for example, the nitrogen content in the film-forming gas can be increased at a temperature below 1000°C. Alternatively, the N / (C+N) ratio of the TiCN film can be 0.9 or less. Note that N / (C+N) is calculated as an atomic ratio.

[0050] For example, when the Al2O3 layer 8 is not in contact with the TiCN film, N / (C+N) may be lower than 0.7. Alternatively, N / (C+N) may be greater than 0.5.

[0051] N / (C+N) may be the content ratio of N in terms of atomic ratio to the total of C and N. N / (C+N) can be measured by, for example, energy dispersive X-ray analysis (EDS).

[0052] Furthermore, the surface layer 9 may include a TiN layer, a TiC layer, and a TiCN layer in order from the side of the Al2O3 layer 8. The surface layer 9 having such a structure has excellent wear resistance and the surface of the coating film 3 is easily peeled off.

[0053] <Method for manufacturing coated cutting tools>

[0054] Next, a method for manufacturing a coated tool according to a non-limiting embodiment of the present invention will be described by taking as an example a case where the coated tool 1 having the above-described evaluation results in the MSE test is manufactured.

[0055] The substrate 2 can be made first. As the substrate 2, the case of making a substrate 2 composed of cemented carbide is used as an example for explanation. First, metal powder, carbon powder, etc. can be appropriately added to the inorganic powder of metal carbide, nitride, carbonitride, oxide, etc. that can be formed into the substrate 2 by firing to obtain a mixed powder. Secondly, this mixed powder can be formed into a specified tool shape by a known forming method such as stamping, casting, extrusion, cold isostatic pressing, etc. to obtain a formed body. Then, the obtained formed body can be fired in a vacuum or a non-oxidizing atmosphere to obtain the substrate 2. The surface 4 of the substrate 2 can be subjected to grinding or honing.

[0056] Next, the coating 3 can be formed on the surface 4 of the obtained substrate 2 by CVD method to obtain the coated tool 1.

[0057] The Al2O3 layer 8 can be formed as follows. First, the reaction gas composition can be adjusted to form a mixed gas comprising 0.5-5% by volume of aluminum chloride (AlCl3) gas, 0.5-3.5% by volume of hydrogen chloride (HCl) gas, 0.5-5% by volume of carbon dioxide (CO2) gas, less than 0.5% by volume of hydrogen sulfide (H2S) gas, and the remainder being hydrogen (H2) gas. This mixed gas can then be introduced into a furnace, set at a temperature of 930-1010°C, a pressure of 5-10 kPa, and a time of 30-300 minutes to form the Al2O3 layer 8.

[0058] The TiN film of surface layer 9 can be formed as follows. First, the reaction gas composition can be adjusted to form a mixed gas consisting of 0.1 to 10% by volume of titanium tetrachloride (TiCl₄) gas, 10 to 60% by volume of nitrogen (N₂) gas, and the remainder of hydrogen (H₂) gas. This mixed gas can then be introduced into a furnace, set at a temperature of 800 to 1010°C, a pressure of 10 to 85 kPa, and a time of 5 to 90 minutes to form the TiN film.

[0059] The TiC film of surface layer 9 can be formed as follows. First, the reaction gas composition can be adjusted to form a mixed gas consisting of 0.1 to 30% by volume of titanium tetrachloride (TiCl4) gas, 0.1 to 20% by volume of methane (CH4) gas, and the remainder of hydrogen (H2) gas. This mixed gas is then introduced into a furnace, set at a temperature of 800 to 1100°C, a pressure of 5 to 85 kPa, and a time of 5 to 90 minutes to form the TiC film.

[0060] The TiCN film of surface layer 9 can be formed as follows. First, the reaction gas composition can be adjusted to form a mixed gas comprising 0.1 to 10% by volume of titanium tetrachloride (TiCl₄) gas, 10 to 60% by volume of nitrogen (N₂) gas, 0.1 to 20% by volume of methane (CH₄) gas, and the remainder of hydrogen (H₂) gas. This mixed gas can then be introduced into a furnace, set at a temperature of 800 to 1050°C, a pressure of 5 to 30 kPa, and a time of 5 to 90 minutes to form the TiCN film.

[0061] In the surface layer 9, for example, by controlling the combination of TiN film, TiCN film, TiC film, etc., the stacking order, or the N content in the TiCN film, etc., the coated tool 1 having the above-mentioned first erosion rate and second erosion rate can be obtained.

[0062] In the obtained coated tool 1, the region including the cutting edge 7 can be subjected to grinding. This makes the region including the cutting edge 7 smooth, thereby suppressing adhesion of the workpiece and improving the chipping resistance of the cutting edge 7.

[0063] The above-mentioned manufacturing method is an example of a method for manufacturing the coated tool 1. Therefore, the coated tool 1 is not limited to being manufactured by the above-mentioned manufacturing method.

[0064] Cutting Tools

[0065] like Figure 4 As a non-limiting example, a cutting tool 101 according to a non-limiting embodiment of the present invention may include: a tool holder 102 having a length from a first end 102a to a second end 102b and having a groove 103 located at the first end 102a; and a coated tool 1 located at the groove 103. Figure 4 In the example shown, the coated blade 1 has a through hole, and the coated blade 1 is fixed to the clamping groove 103 with a screw 104 through the through hole.

[0066] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.

[0067] Example

[0068] [Samples No. 1 to 13]

[0069] <Production of Coated Tools>

[0070] First, a matrix is ​​prepared. Specifically, for WC powder with an average particle size of 1.2 μm, 6% by mass of metal Co powder with an average particle size of 1.5 μm, 2.0% by mass of TiC (titanium carbide) powder, and 0.2% by mass of Cr3C2 (chromium carbide) powder are added and mixed, and formed into a cutting tool shape (CNMG120408) by stamping to obtain a formed body. The obtained formed body is dewaxed and sintered at 1400°C for 1 hour in a vacuum of 0.5 to 100 Pa to produce a matrix composed of cemented carbide. The front cutting edge (first surface) side of the prepared matrix is ​​subjected to edge treatment (R honing) by brushing.

[0071] Next, a coating layer (surface layer) was formed on the obtained substrate by CVD under the film formation conditions shown in Table 1, thereby obtaining a coated tool (cutting insert) shown in Table 2.

[0072] In addition, the coated tools shown in Table 2 all have an Al2O3 layer formed on the substrate. The film formation conditions and thickness of the Al2O3 layer are as follows.

[0073] AlCl3 gas: 4.0 volume%

[0074] HCl gas: 2.0% by volume

[0075] CO2 gas: 4.0% by volume

[0076] H2S gas: 0.3% by volume

[0077] H2 gas: balance

[0078] Temperature: 1000℃

[0079] Pressure: 5kPa

[0080] Duration: 240 minutes

[0081] Thickness: 4.0μm

[0082] In Tables 1 and 2, each compound is represented by its chemical symbol. The coating thickness shown in Table 1 and the Al2O3 layer thickness described above are values ​​obtained by cross-sectional observation using a SEM. Furthermore, N / (C+N) in the tables represents the atomic ratio.

[0083] <Evaluation>

[0084] The erosion rate of the obtained coated tool was measured. The measurement method is shown below, and the results are shown in Table 2.

[0085] (Erosion rate)

[0086] Liquid A or B was applied at a speed of 100 m / s from a direction perpendicular to the surface of the coating film, and the first and second erosion rates (μm / minute) were measured. The erosion rate measurements were performed using the MSE testing machine "MSE-Al2O3" manufactured by Palmeso Co., Ltd. Amorphous Al2O3 particles were tested using the "MSE-GA-1-3" manufactured by Palmeso, with an average particle size of 1.2 μm. Spherical Al2O3 particles were tested using the "MSE-BA-3-3" manufactured by Palmeso, with an average particle size of 3.0 μm.

[0087] (Cutting performance)

[0088] The obtained coated tools were then subjected to cutting evaluation to evaluate the wear resistance and fracture resistance of the produced coated tools. The evaluation conditions are shown below. The evaluation results are shown in Table 2.

[0089] Wear resistance evaluation

[0090] Processing method: turning

[0091] Workpiece: S45C round bar

[0092] Cutting speed: 200m / min

[0093] Cutting depth: 1.5mm

[0094] Feed: 0.3mm / rev

[0095] Processing state: wet

[0096] Judgment method: Evaluation of cutting time when the wear width of the rear blade reaches 0.3mm

[0097] Evaluation of fracture resistance

[0098] Processing method: turning

[0099] Workpiece: S45C 16-slot round bar

[0100] Cutting speed: 100m / min

[0101] Cutting depth: 1.0mm

[0102] Feed: 0.3mm / rev

[0103] Processing state: wet

[0104] Judgment method: Evaluate the cutting time until the cutting edge is damaged

[0105]

Table 1

[0106]

[0107]

Table 2

[0108]

[0109] As shown in Table 2, Comparative Example samples No. 1, 2, 3, 5, 7, 10, 11, and 13 had poor wear resistance or chipping resistance on the flank surface. On the other hand, the coated cutting tools of the present invention all had excellent wear resistance and chipping resistance.

[0110] Symbol explanation

[0111] 1…Coated tools (cutting inserts)

[0112] 2…Matrix

[0113] 3…Coating

[0114] 4…Surface

[0115] 5…side 1

[0116] 6…side 2

[0117] 7…Blade

[0118] 8…Al2O3 layer

[0119] 9…Surface layer

[0120] 10…First surface

[0121] 11…Second surface

[0122] 101…Cutting tools

[0123] 102…Handle

[0124] 102a…first end

[0125] 102b…Second end

[0126] 103…Card slot

[0127] 104…screw

Claims

1. A coated tool comprising a substrate and a coating film located on the substrate, wherein: The coating film has: Al2O3 layer; a surface layer located from the first surface of the Al2O3 layer on the side away from the substrate to the second surface as the coating surface, In this surface layer, The first erosion rate measured by causing liquid A containing 3% by mass of amorphous Al2O3 particles having an average particle size of 1.1 to 1.3 μm to be dispersed in pure water to impact the surface layer at a speed of 98 to 102 m / s is 0.1 μm / min or less. The second erosion rate measured by causing Liquid B, in which 3% by mass of spherical Al2O3 particles having an average particle size of 2.8 to 3.2 μm are dispersed in pure water, to impact the surface layer at a speed of 98 to 102 m / s is 2.0 μm / min or more. The surface layer includes a TiN layer, a TiC layer, and a TiCN layer in order from the Al 2 O 3 layer side.

2. The coated tool according to claim 1, wherein: The surface layer has a TiCN layer containing Ti, C, and N, N / (C+N) in the TiCN layer is 0.7 or more.

3. A coated tool comprising a substrate and a coating film located on the substrate, wherein: The coating film has: Al2O3 layer; a surface layer located from the first surface of the Al2O3 layer on the side away from the substrate to the second surface as the coating surface, In this surface layer, The first erosion rate measured by causing liquid A containing 3% by mass of amorphous Al2O3 particles having an average particle size of 1.1 to 1.3 μm to be dispersed in pure water to impact the surface layer at a speed of 98 to 102 m / s is 0.1 μm / min or less. The second erosion rate measured by causing Liquid B, in which 3% by mass of spherical Al2O3 particles having an average particle size of 2.8 to 3.2 μm are dispersed in pure water, to impact the surface layer at a speed of 98 to 102 m / s is 2.0 μm / min or more. The surface layer has any one selected from the following (1) to (4) in order from the Al2O3 layer side: (1) TiCN layer, TiN layer, TiC layer, TiCN layer; (2) TiN layer, TiC layer, TiN layer; (3) TiN layer, TiCN layer, TiC layer; (4) TiN layer and TiC layer.

4. A cutting tool comprising: A knife handle having a length from a first end to a second end and having a slot located on a side of the first end; The coated cutting tool according to any one of claims 1 to 3 is located in the groove.

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