Coated and cutting tools

Abstract

A coated tool according to the present disclosure comprises a base material, and a coating layer that is positioned on the base material. The coating layer comprises a first coating layer that contains Al, Cr, Si and N. The first coating layer comprises first layers and second layers, which are alternately arranged in the thickness direction. The first layers and the second layers contain Al, Cr, Si and N. The Al content in the first layers is expressed as the first Al content; the Cr content in the first layers is expressed as the first Cr content; the Si content in the first layers is expressed as the first Si content; the Al content in the second layers is expressed as the second Al content; the Cr content in the second layers is expressed as the second Cr content; and the Si content in the second layers is expressed as the second Si content. In this case, the first Al content is higher than the second Al content; the first Cr content is lower than the second Cr content; and the first Si content is higher than the second Si content.

Description

[Technical field]

[0001] The present disclosure relates to coated tools and cutting tools. [Background technology]

[0002] 2. Description of the Related Art As tools used in cutting processes such as turning and milling, coated tools are known in which the surface of a substrate made of cemented carbide, cermet, ceramics, or the like is coated with a coating layer to improve wear resistance and the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-50381 A [Patent Document 2] JP 2018-30212 A Summary of the Invention

[0004] A coated tool according to one embodiment of the present disclosure has a substrate and a coating layer located 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 located 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 the first Al content, the Cr content in the first layer is the first Cr content, the Si content in the first layer is the first Si content, the Al content in the second layer is the second Al content, the Cr content in the second layer is the second Cr content, and the Si content in the second layer is 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. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a perspective view showing an example of a coated tool according to an embodiment. [Diagram 2]FIG. 2 is a side cross-sectional view showing an example of a coated tool according to an embodiment. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of a coating layer according to the embodiment. [Figure 4] FIG. 4 is a schematic enlarged view of a portion H shown in FIG. [Diagram 5] FIG. 5 is a schematic diagram for illustrating the Al content, the Cr content, and the Si content of the first layer and the second layer. [Figure 6] FIG. 6 is a front view showing an example of a cutting tool according to an embodiment. [Figure 7] FIG. 7 is a table summarizing the manufacturing conditions of the first coating layer for samples No. 1 to No. 16. [Figure 8] FIG. 8 is a table summarizing the measurement results of the composition and metal content of the first coating layer for Samples No. 1 to No. 16. [Figure 9] FIG. 9 is a table summarizing the results of the wear tests on Samples No. 1 to No. 16. [Figure 10] FIG. 10 is a scanning transmission electron microscope image of the first coating layer according to the embodiment. [Figure 11] FIG. 11 is a graph showing changes in the Al content, Cr content, Si content and N content in the stacking direction of the first layer and the second layer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Hereinafter, a detailed description will be given of a form for carrying out a coated tool and a cutting tool according to the present disclosure (hereinafter, referred to as an "embodiment") with reference to the drawings. Note that the coated tool and the cutting tool according to the present disclosure are not limited to the embodiment. Moreover, each embodiment can be appropriately combined as long as the processing contents are not contradictory. Moreover, the same parts in each of the following embodiments are given the same reference numerals, and duplicated explanations will be omitted.

[0007] In addition, in the embodiments described below, expressions such as "constant", "orthogonal", "vertical" and "parallel" may be used, but these expressions do not necessarily mean "constant", "orthogonal", "vertical" and "parallel" strictly. In other words, each of the above expressions allows for deviations due to, for example, manufacturing accuracy and installation accuracy.

[0008] The above-mentioned conventional techniques have room for further improvement in terms of improving fracture resistance.

[0009] <Coated tools> Fig. 1 is a perspective view showing an example of a coated tool according to an embodiment. Fig. 2 is a side cross-sectional view showing an example of a coated tool 1 according to an embodiment. As shown in Fig. 1, the coated tool 1 according to the embodiment has a tip body 2.

[0010] (Chip body 2) Chip body 2 has, for example, a hexahedral shape in which the upper and lower surfaces (surfaces intersecting with the Z-axis shown in FIG. 1) are parallelogram-shaped.

[0011] One corner of the tip body 2 functions as a cutting edge portion. The cutting edge portion has a first surface (e.g., an upper surface) and a second surface (e.g., a side surface) connected to the first surface. In the embodiment, the first surface functions as a "scooping surface" that scoops up chips generated by cutting, and the second surface functions as a "flank surface." A cutting edge is located at least in a part of the ridge where the first surface and the second surface intersect, and the coated tool 1 cuts the workpiece by applying the cutting edge to the workpiece.

[0012] A through hole 5 that vertically passes through the tip body 2 is located in the center of the tip body 2. A screw 75 for attaching the coated tool 1 to a holder 70 (described later) is inserted into the through hole 5 (see FIG. 6).

[0013] As shown in FIG. 2, the chip body 2 has a base 10 and a covering layer 20.

[0014] (Base 10) The substrate 10 is formed of, for example, a cemented carbide. The cemented carbide contains W (tungsten), specifically WC (tungsten carbide). The cemented carbide may also contain Ni (nickel) and / or Co (cobalt). Specifically, the substrate 10 is made of a WC-based cemented carbide containing WC particles as a hard phase component and Co as a main component of a binder phase.

[0015] The substrate 10 may be made of a cermet. The cermet contains, for example, Ti (titanium), specifically, TiC (titanium carbide) or TiN (titanium nitride). The cermet may also contain Ni or Co.

[0016] The substrate 10 may be formed of a cubic boron nitride sintered body containing cubic boron nitride (cBN) particles. The substrate 10 is not limited to cubic boron nitride (cBN) particles, and may contain particles of hexagonal boron nitride (hBN), rhombohedral boron nitride (rBN), wurtzite boron nitride (wBN), or the like.

[0017] (Coating layer 20) The coating layer 20 is applied to the substrate 10 for the purpose of improving the wear resistance, heat resistance, etc. of the substrate 10. In the example of FIG. 2, the coating layer 20 covers the entire substrate 10. The coating layer 20 needs to be located at least on the substrate 10. When the coating layer 20 is located on the first surface (here, the upper surface) of the substrate 10, the wear resistance and heat resistance of the first surface are high. When the coating layer 20 is located on the second surface (here, the side surface) of the substrate 10, the wear resistance and heat resistance of the second surface are high.

[0018] Here, a specific configuration of the coating layer 20 will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a cross-sectional view showing an example of the coating layer 20 according to the embodiment. Fig. 4 is a schematic enlarged view of a portion H shown in Fig. 3.

[0019] As shown in FIG. 3, the coating layer 20 has a first coating layer 23 located on the intermediate layer 22 and a second coating layer 24 located on the first coating layer 23.

[0020] (First coating layer 23) The first coating layer 23 contains 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, Si, and Cr.

[0021] Specifically, the first coating layer 23 contains Al, Cr, Si, and N. That is, the first coating layer 23 may be an AlCrSiN layer containing AlCrSiN, which is a nitride of Al, Cr, and Si. Note that the expression "AlCrSiN" means that Al, Cr, Si, and N are present in any ratio, and does not necessarily mean that Al, Cr, Si, and N are present in a 1:1:1:1:1 ratio.

[0022] In this manner, by positioning the first coating layer 23 containing the metal (for example, Si) contained in the intermediate layer 22 on the intermediate layer 22, the adhesion between the intermediate layer 22 and the coating layer 20 is high. This makes it difficult for the coating layer 20 to peel off from the intermediate layer 22, and therefore the durability of the coating layer 20 is high.

[0023] 4, the first coating layer 23 has a plurality of first layers 23a and a plurality of second layers 23b. The first coating layer 23 has a striped structure in which the first layers 23a and the second layers 23b are alternately laminated in the thickness direction. The first layers 23a are in contact with the intermediate layer 22, and the second layers 23b are formed on the first layers 23a.

[0024] The thickness of each of the first layer 23a and the second layer 23b may be 50 nm or less. The first layer 23a and the second layer 23b formed thinly have small residual stress and are less likely to peel off or crack, so that the durability of the coating layer 20 is increased.

[0025] The second coating layer 24 may contain Ti, Si, and N. That is, the second coating layer 24 may be a nitride layer (TiSiN layer) containing Ti and Si. Note that the expression "TiSiN layer" means that Ti, Si, and N are present in any ratio, and does not necessarily mean that Ti, Si, and N are present in a 1:1:1 ratio.

[0026] As a result, for example, when the friction coefficient of the second coating layer 24 is low, the adhesion resistance of the coated tool 1 can be improved. Also, for example, when the hardness of the second coating layer 24 is high, the wear resistance of the coated tool 1 can be improved. Also, for example, when the oxidation onset temperature of the second coating layer 24 is high, the oxidation resistance of the coated tool 1 can be improved.

[0027] FIG. 5 is a schematic diagram for illustrating the Al content, the Cr content, and the Si content of the first layer 23a and the second layer 23b.

[0028] 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 is referred to as the first Cr content, and the Si content in the first layer 23a is referred to as the first Si content. The Al content in the second layer 23b is referred to as the second Al content, the Cr content in the second layer 23b is referred to as the second Cr content, and the Si content in the second layer 23b is referred to as the second Si content.

[0029] In this case, the first Al content may be greater than the second Al content, the first Cr content may be less than the second Cr content, and the first Si content may be greater than the second Si content.

[0030] The coated tool 1 having the first coating layer 23 having such a configuration has high hardness and excellent chipping resistance.

[0031] Furthermore, the total content of Al, Cr, and Si in the metal elements contained in the first coating layer 23 may be 98 atomic % or more.

[0032] The coated tool 1 having the first coating layer 23 having such a configuration has even higher hardness and excellent chipping resistance.

[0033] The ratio of Al to the metal elements in the first coating layer 23 may be 38 atomic % or more and 55 atomic % or less. The ratio of Cr to the metal elements in the first coating layer 23 may be 33 atomic % or more and 48 atomic % or less. The ratio of Si to the metal elements in the first coating layer 23 may be 4 atomic % or more and 15 atomic % or less.

[0034] The coated tool 1 having the first coating layer 23 having such a configuration has improved oxidation resistance and excellent wear resistance.

[0035] The difference between the first Al content and the second Al content may be 1 atomic % or more and 9 atomic % or less.

[0036] The coated tool 1 having the first coating layer 23 having such a configuration maintains high oxidation resistance and high hardness, while relieving stress inside the coating layer and providing excellent wear resistance.

[0037] The coated tool 1 having the first coating layer 23 having such a configuration has particularly high hardness.

[0038] The difference between the first Cr content and the second Cr content may be 1 atomic % or more and 12 atomic % or less.

[0039] The coated tool 1 having the first coating layer 23 having such a configuration has even more excellent wear resistance.

[0040] The coated tool 1 having the first coating layer 23 having such a configuration is particularly excellent in fracture resistance.

[0041] The difference between the first Si content and the second Si content may be 0.5 atomic % or more and 5 atomic % or less.

[0042] The coated tool 1 having the first coating layer 23 having such a configuration has particularly high hardness.

[0043] The thickness of the first layer 23a and the second layer 23b may be not less than 1 nm and not more than 20 nm.

[0044] The coated tool 1 having the first coating layer 23 having such a configuration is excellent in hardness and chipping resistance.

[0045] (Middle layer 22) An intermediate layer 22 may be located between the substrate 10 and the coating layer 20. Specifically, the intermediate layer 22 contacts the upper surface of the substrate 10 on one side (here, the lower surface) and contacts the lower surface of the coating layer 20 (first coating layer 23) on the other side (here, the upper surface).

[0046] The intermediate layer 22 has higher adhesion to the substrate 10 than the coating layer 20. Examples of metal elements having such properties include Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Y, and Ti. The intermediate layer 22 contains at least one of the above metal elements. For example, the intermediate layer 22 may contain Ti. Note that Si is a metalloid element, but in this specification, metalloid elements are also included in the metal elements.

[0047] When the intermediate layer 22 contains Ti, the Ti content in the intermediate layer 22 may be 1.5 atomic % or more. For example, the Ti content in the intermediate layer 22 may be 2.0 atomic % or more.

[0048] The intermediate layer 22 may contain metal elements other than the above metal elements (Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Y, Ti). However, from the viewpoint of adhesion to the substrate 10, the intermediate layer 22 may contain the above metal elements in a total amount of at least 95 atomic % or more. More preferably, the intermediate layer 22 may contain the above metal elements in a total amount of 98 atomic % or more. The proportion of the metal components in the intermediate layer 22 can be determined, for example, by analysis using an EDS (energy dispersive X-ray spectrometer) attached to a STEM (scanning transmission electron microscope).

[0049] In this way, in the coated tool 1 according to the embodiment, the intermediate layer 22, which has higher wettability with the substrate 10 than the coating layer 20, is provided between the substrate 10 and the coating layer 20, thereby improving the adhesion between the substrate 10 and the coating layer 20. Since the intermediate layer 22 also has high adhesion with the coating layer 20, peeling of the coating layer 20 from the intermediate layer 22 is unlikely to occur.

[0050] The thickness of the intermediate layer 22 may be, for example, not less than 0.1 nm and less than 20.0 nm.

[0051] <Cutting tools> Next, the configuration of a cutting tool including the above-mentioned coated tool 1 will be described with reference to Fig. 6. Fig. 6 is a front view showing an example of a cutting tool according to an embodiment.

[0052] As shown in FIG. 6, a cutting tool 100 according to the embodiment includes a coated tool 1 and a holder 70 for fixing the coated tool 1.

[0053] The holder 70 is a rod-shaped member extending from a first end (the upper end in FIG. 6) to a second end (the lower end in FIG. 6). The holder 70 is made of, for example, steel or cast iron. Of these materials, it is particularly preferable to use steel, which has high toughness.

[0054] The holder 70 has a pocket 73 at the end on the first end side. The pocket 73 is a portion where the coated tool 1 is attached, and has a seating surface that intersects with the rotation direction of the workpiece and a constraint side surface that is inclined relative to the seating surface. The seating surface is provided with a screw hole into which a screw 75, which will be described later, is screwed.

[0055] The coated tool 1 is positioned in a pocket 73 of the holder 70, and is attached to the holder 70 by a screw 75. That is, the screw 75 is inserted into the through hole 5 of the coated tool 1, and the tip of the screw 75 is inserted into a screw hole formed in the seating surface of the pocket 73 to screw the threaded portions together. In this way, the coated tool 1 is attached to the holder 70 such that the cutting edge portion protrudes outward from the holder 70.

[0056] In the embodiment, a cutting tool used in so-called turning is exemplified. Examples of turning include inner diameter machining, outer diameter machining, and grooving. The cutting tool is not limited to that used in turning. For example, the coated tool 1 may be used as a cutting tool used in turning. Examples of cutting tools used in turning include milling cutters such as flat milling cutters, face milling cutters, side milling cutters, and groove milling cutters, and end mills such as single-blade end mills, multiple-blade end mills, tapered-blade end mills, and ball end mills.

[0057] (Manufacturing method) Next, an example of a method for producing the coated tool 1 according to the present embodiment will be described. Note that the method for producing the coated tool according to the present disclosure is not limited to the following method.

[0058] The coating layer may be formed by, for example, a physical vapor deposition method. Examples of the physical vapor deposition method include an ion plating method and a sputtering method. As an example, when the coating layer is formed by an ion plating method, the coating layer can be formed by the following method.

[0059] First, an example of a method for producing the first coating layer 23 by an ion plating method will be described. First, as an example, metal targets of Cr, Si and Al, or composite alloy targets, or sintered compact targets are prepared.

[0060] Next, the above target, which is the metal source, is evaporated and ionized by arc discharge or glow discharge. The ionized metal is reacted with nitrogen (N2) gas, which is the nitrogen source, and is evaporated onto the surface of the substrate. The above procedure makes it possible to form an AlCrSiN layer.

[0061] In the above procedure, the temperature of the substrate may be set to 500 to 600° C., the nitrogen gas pressure may be set to 1.0 to 6.0 Pa, a DC bias voltage of −50 to −200 V may be applied to the substrate, and the arc discharge current may be set to 100 to 200 A.

[0062] The composition of the first coating layer can be adjusted by independently controlling the voltage and current values ​​during arc discharge and glow discharge applied to the aluminum metal target, the chromium metal target, the aluminum-silicon composite alloy target, and the chromium-silicon composite alloy target for each target. The composition of the coating layer can also be adjusted by controlling the coating time and the atmospheric gas pressure. In one embodiment, the amount of ionization of the target metal can be changed by changing the voltage and current values ​​during arc discharge and glow discharge. The amount of ionization of the target metal can be changed periodically by periodically changing the current value during arc discharge and glow discharge for each target. The amount of ionization of the target metal can be changed periodically by periodically changing the current value during arc discharge and glow discharge of the target at intervals of 0.01 to 0.5 min. This allows the coating layer to have a configuration in which the content ratio of each metal element changes in each period in the thickness direction.

[0063] When carrying out the above procedure, it is possible to produce a first coating layer having a first layer and a second layer by changing the composition of Al, Si, and Cr so that the amounts of Al and Si are smaller and the amount of Cr is larger, and then changing the composition of Al, Si, and Cr so that the amounts of Al and Si are larger and the amount of Cr is smaller.

[0064] Next, an example of a method for producing the second coating layer, which is a TiSiN layer, will be described.

[0065] Like the first coating layer, the second coating layer may also be formed by physical vapor deposition. As an example, a Ti metal target and a Ti-Si composite alloy target are first prepared. Then, the voltage and current values ​​during arc discharge and glow discharge applied to each prepared target are independently controlled for each target, thereby producing a second coating layer having a striped structure.

[0066] In the above procedure, the substrate temperature may be set to 500 to 600° C., the nitrogen gas pressure may be set to 1.0 to 6.0 Pa, a DC bias voltage of −50 to −200 V may be applied to the substrate, the arc discharge current may be set to 100 to 200 A, and the change period of the arc current may be set to 0.01 to 0.5 min. EXAMPLES

[0067] Examples of the present disclosure will be specifically described below. Note that the present disclosure is not limited to the examples shown below.

[0068] Coated tools having a first coating layer formed on a substrate made of WC were fabricated as samples No. 1 to No. 16. Fig. 7 is a table summarizing the manufacturing conditions of the first coating layer for samples No. 1 to No. 16. Among samples No. 1 to No. 16, samples No. 1 to No. 11 and No. 14 to No. 16 correspond to examples of the present disclosure. Among samples No. 1 to No. 16, samples No. 12 and No. 13 correspond to comparative examples.

[0069] First, various metal targets, composite alloy targets, or sintered targets were prepared. Specifically, three types of targets (first target to third target) were prepared. Next, the above targets, which are metal sources, were evaporated and ionized by arc discharge or glow discharge. Next, the ionized metal was reacted with nitrogen (N2) gas, which is a nitrogen source, and was deposited on the surface of the substrate. The above procedure was used to form a first coating layer on the substrate. In addition, the current value during arc discharge and glow discharge was periodically changed for each target. This allows the amount of ionization of the target metal to be periodically changed, and the content ratio of each metal element in the thickness direction of the first coating layer can be configured to change in each period.

[0070] The manufacturing conditions of the first coating layer for each of Samples No. 1 to No. 16 are as shown in FIG. 7. Samples No. 1 to No. 9 and No. 11 to No. 15, except for 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. Samples No. 1 to No. 9 and No. 11 to No. 15 have different combinations of arc current period, arc current magnitude when forming the first layer and the second layer on the first target, arc current magnitude when forming the first layer and the second layer on the second target, and arc current magnitude when forming the first layer and the second layer on the third target. Sample No. 10 used an Al metal target as the first target, a Cr metal target as the second target, and an Al-Si-Ti composite alloy target as the third target.

[0071] FIG. 8 is a table summarizing the measurement results of the composition and metal content of the first coating layer for Samples No. 1 to No. 16.

[0072] As shown in FIG. 8, the average composition of the first coating layer of samples No. 1 to No. 9, No. 11, and No. 14 to No. 16 was (Al 50 Cr 39 S 11 )N, and the average composition of the first coating layer of sample No. 10 is (Al 50 Cr 39 S 11 The average composition of the first coating layer of sample No. 12 is (Al 69 Cr 11 S 20 )N, and the average composition of the first coating layer of sample No. 13 is (Al 70 Cr 10 S 20)N. For samples No. 1 to No. 16, except for sample No. 10, the total of Al, Cr, and Si in the metallic elements contained in the first coating layer is 100 atomic %. For sample No. 10, the total of Al, Cr, and Si in the metallic elements contained in the first coating layer is 97 atomic %.

[0073] The thickness (average thickness) of the first and second layers in Samples No. 1 to No. 13 is about 5 nm. The thickness (average thickness) of the first and second layers in Sample No. 14 is about 10 nm, the thickness (average thickness) of the first and second layers in Sample No. 15 is about 20 nm, and the thickness (average thickness) of the first and second layers in Sample No. 16 is about 30 nm.

[0074] For samples No. 1 to No. 16, the differences between the first Al content and the second Al content (first Al content - second Al content) were 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%, and 6 atomic%, respectively.

[0075] Furthermore, for samples No. 1 to No. 16, the differences between the first Cr content and the second Cr content (second Cr content - first Cr content) were 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%, respectively.

[0076] In addition, for samples No. 1 to No. 16, the differences between the first Si content and the second Si content (first Si content - second Si content for samples No. 1 to No. 10 and No. 13 to No. 16, and second Si content - first Si content for samples No. 11 and No. 12) were 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%, and 2 atomic%, respectively.

[0077] Figure 9 is a table summarizing the results of the wear tests for Samples No. 1 to No. 16. The test conditions for each wear test are as follows.

[0078] <Wear Test> The wear test was conducted under the following conditions using a two-flute carbide ball end mill (model number: 2KMBL0200 - 0800 - S4). (1) Cutting method: Pocket machining (2) Workpiece material: SKD11H (3) Feed per tooth fz: 1320 mm / min (4) Depth of cut: ap 0.08 mm × ae 0.20 mm (5) Evaluation method: The wear width of the side relief face after 20 m of cutting was measured with a microscope.

[0079] Samples No. 1 to 10, No. 13 to No. 16, in which 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, had excellent adhesion of the coating layer and showed high wear resistance. In particular, for Samples No. 1 to No. 6, where the ratio of Al in the metal elements of the first coating layer is 38 atomic % or more and 55 atomic % or less, the ratio of Cr is 33 atomic % or more and 48 atomic % or less, the ratio of Si is 4 atomic % or more and 15 atomic % or less, and the difference between the first Al content and the second Al content is 1 atomic % or more and 9 atomic % or less, the difference between the first Cr content and the second Cr content is 1 atomic % or more and 12 atomic % or less, and the difference between the first Si content and the second Si content is 0.5 atomic % or more and 5 atomic % or less, the result was excellent wear resistance.

[0080] <EDX Analysis> EDX analysis was performed on Sample No. 1. Specifically, a range spanning multiple first layers and second layers was extracted from the EDX analysis data, and for the extracted range, changes in the Al content, Cr content, Si content, and N content in the direction along the lamination direction of the first layer and the second layer (scan direction) were measured. The analysis conditions are as follows. (1) Sample pretreatment: Thinning by the FIB method (μ - sampling method) (2) Elemental analysis (surface analysis) (3) Scanning transmission electron microscope: JEOL JEM-ARM200F (4)Accelerating voltage: 200 kV (5) Beam diameter: approx. 0.2 nmφ (6) Elemental analyzer: JEOL JED-2300T (7) X-ray detector: Si drift detector (8) Energy resolution: Approximately 140 eV (9) X-ray extraction angle: 21.9° (10) Solid angle: 0.98sr (11) Number of captured pixels: 256 x 256

[0081] 10 is a scanning transmission electron microscope image (HAADF-STEM image) of the first coating layer according to the embodiment. As shown in FIG. 10, it can be seen that the first coating layer according to the example has a striped structure in which the first layer and the second layer are alternately positioned.

[0082] Fig. 11 is a graph showing the changes in Al content, Cr content, Si content and N content in the stacking direction of the first layer and the second layer. The horizontal axis of the graph shown in Fig. 11 corresponds to the scanning direction shown in Fig. 10. That is, the start point of the scanning direction shown in Fig. 10 ("0 nm" shown in Fig. 10) corresponds to "0 nm" on the horizontal axis of the graph shown in Fig. 11, and the end point of the scanning direction shown in Fig. 10 ("50 nm" shown in Fig. 7) corresponds to "50 nm" on the horizontal axis of the graph shown in Fig. 11.

[0083] As shown in Fig. 11, it can be seen that the Al content and the Cr content vary periodically along the scanning direction (i.e., the stacking direction of the first layer and the second layer). Specifically, the Al content increases in the first layer and decreases in the second layer. Also, the Cr content decreases in the second layer and increases in the second layer.

[0084] The Si content also varies periodically along the scanning direction. Specifically, the Si content increases in the first layer and decreases in the second layer, similar to the Al content.

[0085] Thus, in the first coating layer of the embodiment, the Al content in the first layer (first Al content) is greater than the Al content in the second layer (second Al content), 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.

[0086] Furthermore, as shown in FIG. 11, it is found that the difference between the first Al content and the second Al content is not less than 1 atomic % and not more than 9 atomic %.

[0087] Furthermore, as shown in FIG. 11, it is understood that the difference between the first Cr content and the second Cr content is not less than 1 atomic % and not more than 12 atomic %.

[0088] Furthermore, as shown in FIG. 11, it is found that the difference between the first Si content and the second Si content is not less than 0.5 atomic % and not more than 5 atomic %.

[0089] As described above, the coated tool according to the embodiment (for example, the coated tool 1) has a base (for example, the base 10) and a coating layer (for example, the coating layer 20) located on the base. The coating layer has a first coating layer (for example, the first coating layer 23) containing Al, Cr, Si, and N. The first coating layer has a first layer (for example, the first layer 23a) and a second layer (for example, the second layer 23b) that are alternately located 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 the first Al content, the Cr content in the first layer is the first Cr content, the Si content in the first layer is the first Si content, the Al content in the second layer is the second Al content, the Cr content in the second layer is the second Cr content, and the Si content in the second layer is 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.

[0090] Therefore, the coated tool according to the embodiment can improve the oxidation resistance and wear resistance.

[0091] 1 is merely an example and does not limit the shape of the coated tool according to the present disclosure. The coated tool according to the present disclosure may have, for example, a rod-shaped main body having a rotation axis and extending from a first end to a second end, a cutting edge located at the first end of the main body, and a groove extending spirally from the cutting edge toward the second end of the main body.

[0092] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0093] 1. Coated tools 2 Chip body 5 Through hole 10 Base 20 Covering layer 22 Middle Class 23 First coating layer 23a 1st layer 23b 2nd layer 24 Second coating layer 70 Holder 73 Pocket 75 Screw 100 cutting tools

Claims

1. A substrate and a coating layer disposed on the substrate, The coating layer has a first coating layer containing Al, Cr, Si, and N, The total content of Al, Cr, and Si in 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 positioned in a thickness direction, the first layer and the second layer each include Al, Cr, Si, and N; The Al content in the first layer is defined as a first Al content, the Cr content in the first layer is defined as a first Cr content, and the Si content in the first layer is defined as a first Si content, When the Al content in the second layer is defined as a second Al content, the Cr content in the second layer is defined as a second Cr content, and the Si content in the second layer is defined as a second Si content, The first Al content is greater than the second Al content, The first Cr content is less than the second Cr content, the first Si content is greater than the second Si content; A coated tool, wherein a difference between the first Si content and the second Si content is 0.5 atomic % or more and 5 atomic % or less.

2. A coated tool as described in claim 1, wherein the second Si content is 10 atomic % or less.

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

4. The coated tool according to claim 1 , wherein a difference between the first Al content and the second Al content is equal to or greater than 1 atomic % and equal to or less than 9 atomic %.

5. The coated tool according to claim 1 , wherein a difference between the first Cr content and the second Cr content is 1 atomic % or more and 12 atomic % or less.

6. The coated tool according to claim 1 , wherein the first layer and the second layer have a thickness of 1 nm or more and 20 nm or less.

7. a rod-shaped holder having a pocket at one end; The coated tool according to any one of claims 1 to 6, which is located in the pocket. A cutting tool having

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