Coated cutting tool and cutting tool

Abstract

The coated cutting tool of the present application has a substrate and a coating layer on the substrate. The coating layer has a first coating layer containing Al, Cr, Si, and N. The first coating layer has a first layer and a second layer alternately arranged in the thickness direction. The first layer and the second layer contain Al, Cr, Si, and N. The Al content in the first layer is referred to as a first Al content, the Cr content in the first layer is referred to as a first Cr content, the Si content in the first layer is referred to as a first Si content, the Al content in the second layer is referred to as a second Al content, the Cr content in the second layer is referred to as a second Cr content, and the Si content in the second layer is referred to as a second Si content. In this case, the first Al content is more than the second Al content, the first Cr content is less than the second Cr content, and the first Si content is more than the second Si content.

Description

Technical Field

[0001] This invention relates to coated cutting tools and cutting tools. Background Technology

[0002] As cutting tools used in cutting processes such as turning and hobbing, coated tools are known to have coatings applied to the surface of substrates such as cemented carbide, cermet, and ceramic, thereby improving their wear resistance and other properties.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2004-50381

[0006] Patent Document 2: Japanese Patent Application Publication No. 2018-30212 Summary of the Invention

[0007] One aspect of the coated cutting tool of the present invention includes a substrate and a coating disposed on the substrate. The coating includes a first coating containing Al, Cr, Si, and N. The first coating has a first layer and a second layer alternately disposed in the thickness direction. The first layer and the second layer contain Al, Cr, Si, and N. The Al content in the first layer is defined as the first Al content, the Cr content in the first layer as the first Cr content, and the Si content in the first layer as the first Si content; the Al content in the second layer is defined as the second Al content, the Cr content in the second layer as the second Cr content, and the Si content in the second layer as the second Si content. In this case, the first Al content is greater than the second Al content, the first Cr content is less than the second Cr content, and the first Si content is greater than the second Si content. Attached Figure Description

[0008] Figure 1 This is a perspective view showing an example of a coated cutting tool according to an embodiment.

[0009] Figure 2 This is a side sectional view showing an example of a coated cutting tool according to an embodiment.

[0010] Figure 3 This is a cross-sectional view showing an example of the coating in an embodiment.

[0011] Figure 4 yes Figure 3 An enlarged schematic diagram of section H is shown.

[0012] Figure 5 This is a schematic diagram used to illustrate the Al, Cr, and Si contents of the first and second layers.

[0013] Figure 6This is a front view showing an example of a cutting tool used in an embodiment.

[0014] Figure 7 This is a table summarizing the manufacturing conditions of the first coating in samples No.1 to No.16.

[0015] Figure 8 This is a table summarizing the measurement results of the composition and metal content of the first coating in samples No.1 to No.16.

[0016] Figure 9 This is a table summarizing the results of wear tests for samples No.1 to No.16.

[0017] Figure 10 This is a scanning transmission electron microscope image of the first coating of the embodiment.

[0018] Figure 11 It is a graph showing the changes in Al, Cr, Si, and N content in the first and second layers along the stacking direction. Detailed Implementation

[0019] Hereinafter, with reference to the accompanying drawings, a detailed description will be provided of embodiments (hereinafter referred to as "Embodiments") of the coated cutting tools and cutting tools used to implement the present invention. However, the coated cutting tools and cutting tools of the present invention are not limited to these embodiments. Furthermore, the embodiments can be suitably combined without departing from the scope of the processing. In the following embodiments, the same reference numerals are used for the same parts, and repeated descriptions are omitted.

[0020] Furthermore, in the embodiments shown below, expressions such as "certain," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not need to be "certain," "orthogonal," "perpendicular," or "parallel" in the strict sense. That is, the above expressions, for example, allow for errors in manufacturing precision, setting precision, etc.

[0021] There is room for further improvement in the aforementioned prior art regarding the enhancement of breakage resistance.

[0022] Coated Cutting Tools

[0023] Figure 1 This is a perspective view illustrating an example of a coated cutting tool according to an embodiment. Additionally, Figure 2 This is a side sectional view showing an example of the coated cutting tool 1 according to the embodiment. Figure 1 As shown, the coated cutting tool 1 of the embodiment has a blade body 2.

[0024] (Blade Body 2)

[0025] Blade body 2, for example, has an upper surface and a lower surface (with) Figure 1The shape of the surfaces intersecting the Z-axis shown is a parallelogram-shaped hexahedron.

[0026] One corner of the blade body 2 functions as a cutting edge. The cutting edge has a first surface (e.g., an upper surface) and a second surface (e.g., a side surface) connected to the first surface. In this embodiment, the first surface functions as a "front face" to scrape away chips generated by cutting, and the second surface functions as a "back face." The cutting edge is located on at least a portion of the edge where the first and second surfaces intersect, and the coated tool 1 cuts the workpiece by bringing this cutting edge into contact with the workpiece.

[0027] A through hole 5 is provided in the center of the blade body 2, extending vertically through the blade body 2. A bolt 75 for mounting the coated tool 1 on the tool holder 70 (described later) is inserted into the through hole 5. Figure 6 ).

[0028] like Figure 2 As shown, the blade body 2 has a substrate 10 and a coating 20.

[0029] (Matrix 10)

[0030] The matrix 10 is formed, for example, of a cemented carbide. The cemented carbide contains W (tungsten), specifically WC (tungsten carbide). Alternatively, the cemented carbide may also contain Ni (nickel) and Co (cobalt). For example, the matrix 10 is formed of a WC-based cemented carbide with WC particles as the hard phase component and Co as the main component of the binder phase.

[0031] Alternatively, the matrix 10 can also be formed of cermet. Cermet, for example, contains Ti (titanium), specifically TiC (titanium carbide) or TiN (titanium nitride). Additionally, cermet can also contain Ni and Co.

[0032] Alternatively, the matrix 10 may also be formed from a cubic boron nitride sintered body containing cubic boron nitride (cBN) particles. The matrix 10 is not limited to cubic boron nitride (cBN) particles, but may also contain hexagonal boron nitride (hBN), rhombohedral boron nitride (rBN), wurtzite boron nitride (wBN), and other particles.

[0033] (Coating 20)

[0034] Coating 20, for example, is applied to the substrate 10 to improve its wear resistance, heat resistance, etc. Figure 2 In this example, coating 20 completely covers the substrate 10. Coating 20 may be located at least on the substrate 10. When coating 20 is located on the first surface (here, the upper surface) of the substrate 10, the first surface has high wear resistance and heat resistance. When coating 20 is located on the second surface (here, the side surface) of the substrate 10, the second surface has high wear resistance and heat resistance.

[0035] Here, refer to Figure 3 The specific structure of coating 20 will be explained. Figure 3 This is a cross-sectional view showing an example of coating 20 in an embodiment. Additionally, Figure 4 It means Figure 3 An enlarged schematic diagram of section H is shown.

[0036] like Figure 3 As shown, coating 20 has a first coating 23 located above intermediate layer 22 and a second coating 24 located above first coating 23.

[0037] (First coating 23)

[0038] The first coating 23 comprises: at least one element selected from the group consisting of Al, Group 5 elements, Group 6 elements and Group 4 elements excluding Ti; at least one element selected from the group consisting of C and N; and Si and Cr.

[0039] Specifically, the first coating 23 contains Al, Cr, Si, and N. That is, the first coating 23 can be an AlCrSiN layer containing AlCrSiN nitrides as Al, Cr, and Si. Also, the expression "AlCrSiN" means that Al, Cr, Si, and N exist in any proportion, and does not mean that Al, Cr, Si, and N must exist in a 1:1:1:1 ratio.

[0040] Thus, by placing the first coating 23 containing the metal (e.g., Si) contained in the intermediate layer 22 on top of the intermediate layer 22, the adhesion between the intermediate layer 22 and the coating 20 is high. As a result, the coating 20 is difficult to peel off from the intermediate layer 22, and therefore the coating 20 has high durability.

[0041] like Figure 4 As shown, the first coating 23 has a plurality of first layers 23a and a plurality of second layers 23b. The first coating 23 has a striped structure in which the first layers 23a and the second layers 23b are alternately stacked in the thickness direction. The first layer 23a is a layer in contact with the intermediate layer 22, and the second layer 23b is formed on the first layer 23a.

[0042] The thicknesses of the first layer 23a and the second layer 23b can be less than 50 nm each. Because the first layer 23a and the second layer 23b are formed very thinly, the residual stress is small, and peeling and cracking are less likely to occur, thus improving the durability of the coating 20.

[0043] The second coating 24 can also contain Ti, Si, and N. That is, the second coating 24 can be a nitride layer (TiSiN layer) containing Ti and Si. Also, the term "TiSiN layer" means that Ti, Si, and N exist in any proportion, and does not mean that Ti, Si, and N must exist in a 1:1:1 ratio.

[0044] Therefore, for example, when the coefficient of friction of the second coating 24 is low, the anti-adhesion property of the coated tool 1 can be improved. Furthermore, for example, when the hardness of the second coating 24 is high, the wear resistance of the coated tool 1 can be improved. Additionally, for example, when the oxidation initiation temperature of the second coating 24 is high, the oxidation resistance of the coated tool 1 can be improved.

[0045] Figure 5 This is a schematic diagram used to illustrate the Al, Cr, and Si contents of the first layer 23a and the second layer 23b.

[0046] The first layer 23a and the second layer 23b contain Al, Cr, Si, and N. Here, the Al content in the first layer 23a is referred to as the first Al content, the Cr content in the first layer 23a as the first Cr content, and the Si content in the first layer 23a as the first Si content. Similarly, the Al content in the second layer 23b is referred to as the second Al content, the Cr content in the second layer 23b as the second Cr content, and the Si content in the second layer 23b as the second Si content.

[0047] In this case, the first Al content can be greater than the second Al content, the first Cr content can be less than the second Cr content, and the first Si content can be greater than the second Si content.

[0048] The coated tool 1 with the first coating 23 having this structure has high hardness and excellent resistance to chipping.

[0049] In addition, the total percentage of Al, Cr and Si in the first coating 23 can be more than 98 atomic%.

[0050] The coated tool 1 with the first coating 23 having this structure has higher hardness and better resistance to chipping.

[0051] Furthermore, the proportion of Al in the metal elements of the first coating 23 can be 38 atomic% or more and 55 atomic% or less. The proportion of Cr in the metal elements of the first coating 23 can be 33 atomic% or more and 48 atomic% or less. The proportion of Si in the metal elements of the first coating 23 can be 4 atomic% or more and 15 atomic% or less.

[0052] The coated cutting tool 1 with the first coating 23 having this structure has improved oxidation resistance and excellent wear resistance.

[0053] In addition, the difference between the first Al content and the second Al content can be more than 1 atomic% and less than 9 atomic%.

[0054] The coated tool 1 with the first coating 23 having this structure maintains high oxidation resistance and high hardness, and also alleviates the stress inside the coating, resulting in excellent wear resistance.

[0055] The coated cutting tool 1 with the first coating 23 having this structure has particularly high hardness.

[0056] In addition, the difference between the first Cr content and the second Cr content can be more than 1 atomic% and less than 12 atomic%.

[0057] The coated cutting tool 1 with the first coating 23 having this structure has better wear resistance.

[0058] The coated cutting tool 1 with the first coating 23 having this structure has particularly excellent resistance to chipping.

[0059] In addition, the difference between the first Si content and the second Si content can be more than 0.5 atomic% and less than 5 atomic%.

[0060] The coated cutting tool 1 with the first coating 23 having this structure has particularly high hardness.

[0061] In addition, the thickness of the first layer 23a and the second layer 23b can be greater than 1 nm and less than 20 nm.

[0062] The coated tool 1 with the first coating 23 having this structure has excellent hardness and chipping resistance.

[0063] (Middle layer 22)

[0064] An intermediate layer 22 may be provided between the substrate 10 and the coating 20. Specifically, the intermediate layer 22 is in contact with the upper surface of the substrate 10 on one side (the lower surface in this case) and with the lower surface of the coating 20 (the first coating 23) on the other side (the upper surface in this case).

[0065] The intermediate layer 22 has a higher bonding strength with the substrate 10 than with the coating 20. Examples of metallic elements possessing this property include Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Y, and Ti. The intermediate layer 22 contains at least one of the aforementioned metallic elements. For example, the intermediate layer 22 may contain Ti. Furthermore, while Si is a half-metal element, in this specification, half-metal elements are also included among metallic elements.

[0066] When the intermediate layer 22 contains Ti, the Ti content in the intermediate layer 22 can be 1.5 atomic% or more. For example, the Ti content in the intermediate layer 22 can be 2.0 atomic% or more.

[0067] The intermediate layer 22 may also contain components other than the aforementioned metallic elements (Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Y, Ti). However, from the viewpoint of bonding with the substrate 10, the intermediate layer 22 contains at least 95 atomic% of the aforementioned metallic elements in total. More preferably, the intermediate layer 22 may contain at least 98 atomic% of the aforementioned metallic elements in total. Furthermore, the proportion of metallic components in the intermediate layer 22 can be specified, for example, by analysis using an EDS (energy-dispersive X-ray spectroscopy) instrument attached to a STEM (scanning transmission electron microscope).

[0068] Thus, in the coated cutting tool 1 of this embodiment, by providing an intermediate layer 22 between the substrate 10 and the coating 20, which has a higher wettability with the substrate 10 than with the coating 20, the adhesion between the substrate 10 and the coating 20 can be improved. Furthermore, because the adhesion between the intermediate layer 22 and the coating 20 is also high, it is difficult for the coating 20 to peel off from the intermediate layer 22.

[0069] Furthermore, the thickness of the intermediate layer 22 can be, for example, greater than 0.1 nm and less than 20.0 nm.

[0070] <Cutting Tools>

[0071] Next, refer to Figure 6 The structure of the cutting tool having the above-mentioned coated tool 1 will be described. Figure 6 This is a front view showing an example of a cutting tool used in an embodiment.

[0072] like Figure 6 As shown, the cutting tool 100 of the embodiment has a coated tool 1 and a tool holder 70 for fixing the coated tool 1.

[0073] The handle 70 is from the first end ( Figure 6 The upper end of the middle) faces the second end ( Figure 6 A rod-shaped member extending from the lower end of the blade. The handle 70 is made of, for example, steel or cast iron. Among these components, high-toughness steel is particularly preferred.

[0074] The tool holder 70 has a groove 73 at its first end. The groove 73 is the part for mounting the coated tool 1, and has a support surface that intersects the rotation direction of the workpiece and a limiting side that is inclined relative to the support surface. On the support surface, there is a threaded hole for tightening the bolt 75, which will be described later.

[0075] The coated cutting tool 1 is located in the slot 73 of the tool holder 70 and is mounted on the tool holder 70 by a bolt 75. That is, the bolt 75 is inserted into the through hole 5 of the coated cutting tool 1, and the front end of the bolt 75 is inserted into the threaded hole formed in the support surface of the slot 73, so that the threads are tightened. Thus, the coated cutting tool 1 is mounted on the tool holder 70 with the cutting edge protruding outward from the tool holder 70.

[0076] In this embodiment, a cutting tool for so-called turning is exemplified. Examples of turning include, for instance, internal diameter machining, external diameter machining, and grooving. However, the cutting tool is not limited to turning. For example, a coated tool 1 can also be used for hobbing. Examples of cutting tools for hobbing include, for instance, end mills such as face mills, front end mills, side end mills, and grooving end mills, as well as end mills such as single-flute end mills, multi-flute end mills, tapered end mills, and ball end mills.

[0077] (Manufacturing method)

[0078] Next, an example of the manufacturing method of the coated cutting tool 1 according to this embodiment will be described. Furthermore, the manufacturing method of the coated cutting tool of the present invention is not limited to the method described below.

[0079] The coating can be formed, for example, by physical vapor deposition. Examples of physical vapor deposition methods include ion plating and sputtering. As an example, when making a coating by ion plating, the coating can be made by the following method.

[0080] First, an example method for preparing the first coating 23 by ion plating is shown. First, as an example, metal targets of Cr, Si and Al, or composite alloy targets, or sintered targets are prepared.

[0081] Secondly, the target, which serves as the metal source, is evaporated and ionized through methods such as arc discharge or glow discharge. The ionized metal reacts with nitrogen (N2) gas, a nitrogen source, and the vapor phase is deposited on the surface of the substrate. Through these steps, an AlCrSiN layer can be formed.

[0082] In the above steps, the temperature of the substrate can be 500-600℃, the nitrogen pressure can be 1.0-6.0Pa, and a DC bias voltage of -50 to -200V can be applied to the substrate to make the arc discharge current 100-200A.

[0083] The composition of the first coating,

[0084] The voltage and current values ​​applied during arc discharge and glow discharge to each of the aluminum, chromium, aluminum-silicon composite, and chromium-silicon composite targets can be adjusted independently. Furthermore, the coating composition can be adjusted by controlling the coating time and atmospheric pressure. In one embodiment, the ionization amount of the target metal can be varied by changing the voltage and current values ​​during arc discharge and glow discharge. Additionally, the ionization amount of the target metal can be periodically varied by periodically changing the current value during arc discharge and glow discharge for each target. By periodically changing the current value during arc discharge and glow discharge of the targets at intervals of 0.01 to 0.5 minutes, the ionization amount of the target metal can be periodically varied. This allows for a structure in which the content ratio of each metal element varies periodically along the thickness direction of the coating.

[0085] When performing the above steps, the composition of Al, Si, and Cr is changed by decreasing the amount of Al and Si and increasing the amount of Cr. Then, the composition of Al, Si, and Cr is changed by increasing the amount of Al and Si and decreasing the amount of Cr. In this way, a first coating having a first layer and a second layer can be manufactured.

[0086] Next, an example of a method for manufacturing a second coating as a TiSiN layer will be described.

[0087] Similar to the first coating, the second coating can also be formed by physical vapor deposition. As an example, firstly, a Ti metal target and a Ti-Si composite alloy target are prepared. Then, by independently controlling the voltage and current values ​​of the arc discharge and glow discharge applied to each prepared target, a second coating with a striped structure can be fabricated.

[0088] In the above steps, the temperature of the substrate can be 500-600℃, the nitrogen pressure can be 1.0-6.0Pa, and a DC bias voltage of -50 to -200V can be applied to the substrate to make the arc discharge current 100-200A and the arc current change period 0.01-0.5min.

[0089] Example

[0090] The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments shown below.

[0091] Coated cutting tools with a first coating formed on a substrate formed by WC were manufactured as test materials No.1 to No.16. Figure 7This is a table summarizing the manufacturing conditions of the first coating in samples No. 1 to No. 16. Furthermore, among samples No. 1 to No. 11 and No. 14 to No. 16, samples No. 12 and No. 13 correspond to comparative examples of the present invention.

[0092] First, various metal targets, composite alloy targets, or sintered targets are prepared. Specifically, three types of targets (target 1 to target 3) are prepared. Second, the targets, which serve as metal sources, are evaporated and ionized by means of arc discharge or glow discharge. Next, the ionized metal is reacted with nitrogen (N2) gas, a nitrogen source, and deposited in the gas phase onto the substrate surface. Through the above steps, a first coating is formed on the substrate. Furthermore, the current value during arc discharge or glow discharge is periodically changed for each target. As a result, the ionization amount of the target metal can be periodically varied, and a structure in which the content ratio of each metal element varies periodically along the thickness direction of the first coating can be formed.

[0093] The manufacturing conditions for the first coating related to each sample No.1 to No.16 are as follows: Figure 7 As shown. Among samples No. 1 to No. 16, samples No. 1 to No. 9 and No. 11 to No. 15 (excluding sample No. 10) used an Al metal target as the first target, a Cr metal target as the second target, and an Al-Si composite alloy target as the third target. The combinations of the arc current period, the magnitude of the arc current during the first and second layer formation corresponding to the first target, the magnitude of the arc current during the first and second layer formation corresponding to the second target, and the magnitude of the arc current during the first and second layer formation corresponding to the third target are different in samples No. 1 to No. 9 and No. 11 to No. 15. In sample No. 10, an Al metal target was used as the first target, a Cr metal target as the second target, and an Al-Si-Ti composite alloy target as the third target.

[0094] Figure 8 This is a table summarizing the measurement results of the composition and metal content of the first coating in samples No.1 to No.16.

[0095] like Figure 8 As shown, the average composition of the first coating of samples No.1 to No.9, No.11, and No.14 to No.16 is (Al) 50 Cr 39 Si 11 The average composition of the first coating of sample No. 10 is (Al) 50 Cr 39 Si 11Ti3)N. Additionally, sample No. 12 has an average composition of (Al) in its first coating. 69 Cr 11 Si 20 The average composition of the first coating of sample No. 13 is (Al) 70 Cr 10 Si 20 Of the samples No. 1 to No. 16, for samples other than No. 10, the total percentage of Al, Cr, and Si in the first coating is 100 atomic%. For sample No. 10, the total percentage of Al, Cr, and Si in the first coating is 97 atomic%.

[0096] The average thickness of the first and second layers in samples No. 1 to No. 13 is approximately 5 nm. In addition, the average thickness of the first and second layers in sample No. 14 is approximately 10 nm, the average thickness of the first and second layers in sample No. 15 is approximately 20 nm, and the average thickness of the first and second layers in sample No. 16 is approximately 30 nm.

[0097] In these samples No.1 to No.16, the difference between the first Al content and the second Al content (first Al content - second Al content) is 6 atomic%, 2 atomic%, 4 atomic%, 6 atomic%, 8 atomic%, 9 atomic%, 10 atomic%, 9 atomic%, 6 atomic%, 6 atomic%, 6 atomic%, 8 atomic%, 6 atomic%, 6 atomic%, 6 atomic%, 6 atomic%, 6 atomic%, 6 atomic%, 6 atomic%, 6 atomic%, 6 atomic%.

[0098] In addition, in samples No.1 to No.16, the difference between the first Cr content and the second Cr content (second Cr content - first Cr content) is 8 atomic%, 3 atomic%, 6 atomic%, 9 atomic%, 12 atomic%, 11 atomic%, 11 atomic%, 13 atomic%, 12 atomic%, 8 atomic%, 4 atomic%, 4 atomic%, 8 atomic%, 8 atomic%, 8 atomic%, and 8 atomic%.

[0099] In addition, the differences between the first Si content and the second Si content in samples No.1 to No.16 (first Si content - second Si content in samples No.1 to No.10 and No.13 to No.16, and second Si content - first Si content in samples No.11 and No.12) are 2 atomic%, 1 atomic%, 2 atomic%, 3 atomic%, 4 atomic%, 2 atomic%, 1 atomic%, 4 atomic%, 6 atomic%, 2 atomic%, 2 atomic%, 4 atomic%, 2 atomic%, 2 atomic%, 2 atomic%, 2 atomic%, 2 atomic%, 2 atomic%.

[0100] Figure 9This is a table summarizing the wear test results for samples No. 1 to No. 16. The test conditions for each wear test are as follows.

[0101] Wear Test

[0102] Wear tests were conducted using a double-edged carbide ball end mill (model: 2KMBL0200-0800-S4) under the following conditions.

[0103] (1) Cutting method: slot machining

[0104] (2) Workpiece material: SKD11H

[0105] (3) Feed rate fz: 1320mm / min

[0106] (4) Cutting depth: ap0.08mm × ae0.20mm

[0107] (5) Evaluation method: The wear width of the cross face after 20m cutting was measured with a microscope.

[0108] Samples No. 1–10 and No. 13–16, where the first Al content is greater than the second Al content, the first Cr content is less than the second Cr content, and the first Si content is greater than the second Si content, exhibit excellent coating adhesion and high wear resistance. In particular, samples No. 1–No. 6, where the proportions of Al, Cr, and Si in the first coating are 38 atomic% to 55 atomic%, 33 atomic% to 48 atomic%, and 4 atomic% to 15 atomic%, and the difference between the first and second Al contents is 1 atomic% to 9 atomic%, the difference between the first and second Cr contents is 1 atomic% to 12 atomic%, and the difference between the first and second Si contents is 0.5 atomic% to 5 atomic%, demonstrate excellent wear resistance.

[0109] <EDX Analysis>

[0110] EDX analysis was performed on sample No. 1. Specifically, multiple regions spanning the first and second layers were extracted from the EDX analysis data. For the extracted regions, the changes in Al, Cr, Si, and N content were measured along the stacking direction of the first and second layers (scanning direction). The analytical conditions are as follows.

[0111] (1) Sample pretreatment: thinning based on FIB method (μ-sampling method)

[0112] (2) Elemental analysis (surface analysis)

[0113] (3) Scanning transmission electron microscope: JEM-ARM200F, manufactured by Nippon Electronics.

[0114] (4) Accelerating voltage: 200kV

[0115] (5) Beam diameter: approximately

[0116] (6) Elemental analysis apparatus: JED-2300T manufactured by Nippon Electronics Co., Ltd.

[0117] (7) X-ray detector: Si drift detector

[0118] (8) Energy resolution: approximately 140 eV

[0119] (9) X-ray extraction angle: 21.9°

[0120] (10) Solid angle: 0.98sr

[0121] (11) Get the number of pixels: 256×256

[0122] Figure 10 This is a scanning transmission electron microscope image (HAADF-STEM image) of the first coating in the embodiment. Figure 10 As shown, the first coating of the embodiment has a striped structure with alternating first and second layers.

[0123] Figure 11 It is a graph showing the changes in Al, Cr, Si, and N content in the first and second layers along the stacking direction. Figure 11 The horizontal axis of the diagram corresponds to Figure 10 The scanning direction is shown. That is, Figure 10 The starting point of the scan direction shown ( Figure 10 The “0nm” shown corresponds to Figure 11 The horizontal axis of the figure shown is "0nm". Figure 10 The end point of the scan direction shown ( Figure 7 The “50nm” shown corresponds to Figure 11 The horizontal axis of the figure shown is "50nm".

[0124] like Figure 11 As shown, the Al and Cr contents vary periodically along the scanning direction (i.e., the stacking direction of the first and second layers). Specifically, the Al content increases in the first layer and decreases in the second layer. Conversely, the Cr content decreases in the second layer and increases in the second layer.

[0125] In addition, the Si content also varies periodically along the scanning direction. Specifically, like the Al content, the Si content increases in the first layer and decreases in the second layer.

[0126] Thus, in the first coating of the embodiment, the Al content (first Al content) in the first layer is greater than the Al content (second Al content) in the second layer, the first Cr content in the first layer is less than the second Cr content in the second layer, and the first Si content in the first layer is greater than the second Si content in the second layer.

[0127] In addition, such as Figure 11 As shown, the difference between the first Al content and the second Al content is more than 1 atomic% and less than 9 atomic%.

[0128] In addition, such as Figure 11 As shown, the difference between the first Cr content and the second Cr content is more than 1 atomic% and less than 12 atomic%.

[0129] In addition, such as Figure 11 As shown, the difference between the first Si content and the second Si content is more than 0.5 atomic% and less than 5 atomic%.

[0130] As described above, the coated cutting tool of the embodiment (for example, coated cutting tool 1) has a substrate (for example, substrate 10) and a coating (for example, coating 20) located on the substrate. The coating includes a first coating (for example, first coating 23) containing Al, Cr, Si, and N. The first coating has a first layer (for example, first layer 23a) and a second layer (for example, second layer 23b) alternately disposed in the thickness direction. The first layer and the second layer contain Al, Cr, Si, and N. The Al content in the first layer is taken as the first Al content, the Cr content in the first layer is taken as the first Cr content, the Si content in the first layer is taken as the first Si content, the Al content in the second layer is taken as the second Al content, the Cr content in the second layer is taken as the second Cr content, and the Si content in the second layer is taken as the second Si content. In this case, the first Al content is greater than the second Al content, the first Cr content is less than the second Cr content, and the first Si content is greater than the second Si content.

[0131] Therefore, the coated cutting tool according to the embodiment can improve oxidation resistance and wear resistance.

[0132] besides, Figure 1 The shape of the coating tool 1 shown is only an example and is not intended to limit the shape of the coating tool of the present invention. The coating tool of the present invention may, for example, have a rotating shaft and a rod-shaped body extending from a first end toward a second end, a cutting edge located at the first end of the body, and a groove extending spirally from the cutting edge toward the second end of the body.

[0133] Further effects and variations can be readily derived by those skilled in the art. Therefore, the invention is presented in a broader manner, not limited to the specific details and representative embodiments expressed and described above. Thus, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0134] Symbol Explanation

[0135] 1 Coated cutting tools

[0136] 2. Blade body

[0137] 5 through holes

[0138] 10 Matrix

[0139] 20 Coatings

[0140] 22 Intermediate Layer

[0141] 23 First Coating

[0142] 23a First Layer

[0143] 23b Second Layer

[0144] 24 Second Coating

[0145] 70 Knife Handle

[0146] 73 Card Slots

[0147] 75 bolts

[0148] 100 Cutting Tools

Claims

1. A coated tool having a substrate and a coating layer on the substrate, the coating layer has a first coating layer containing Al, Cr, Si, and N, the total of Al and Cr and Si among the metal elements contained in the first coating layer is 98 atomic% or more, the first coating layer has a first layer and a second layer alternately arranged in the thickness direction, the first layer and the second layer have Al, Cr, Si, and N, the Al content in the first layer is a first Al content, the Cr content in the first layer is a first Cr content, and the Si content in the first layer is a first Si content, the Al content in the second layer is a second Al content, the Cr content in the second layer is a second Cr content, and the Si content in the second layer is a second Si content, the first Al content is more than the second Al content, the first Cr content is less than the second Cr content, the first Si content is more than the second Si content, the difference between the first Si content and the second Si content is 0.5 atomic% or more and 5 atomic% or less.

2. The coated tool according to claim 1, wherein, the ratio of Al among the metal elements of the first coating layer is 38 atomic% or more and 55 atomic% or less, the ratio of Cr among the metal elements of the first coating layer is 33 atomic% or more and 48 atomic% or less, the ratio of Si among the metal elements of the first coating layer is 4 atomic% or more and 15 atomic% or less.

3. The coated cutting tool of claim 1 wherein, the difference between the first Al content and the second Al content is 1 atomic% or more and 9 atomic% or less.

4. The coated cutting tool of any of claims 1-3 wherein, the difference between the first Cr content and the second Cr content is 1 atomic% or more and 12 atomic% or less.

5. The coated cutting tool of any of claims 1-3 wherein, the thickness of the first layer and the second layer is 1 nm or more and 20 nm or less.

6. A cutting tool having: a shank of a bar shape having a clamping groove at the end portion; the coated tool according to any one of claims 1 to 5 in the clamping groove.

Images