Coated Cutting Tools

Abstract

To provide a coated cutting tool having excellent chipping resistance and wear resistance and a long tool life. [Solution] A coated cutting tool includes a substrate and a coating layer, wherein the coating layer has a compound layer containing a cubic compound composed of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Al, Si, and B, and at least one element selected from the group consisting of C, N, and O, the compound layer having an average thickness of 0.5 μm to 5.0 μm, and when the maximum intensity in the range of 0° to 90° in an X-ray intensity distribution of an α axis of a pole figure for a (200) plane of the cubic crystal of the compound layer is defined as Ia, the angle α indicating Ia is a is more than 40° and less than 60°, and the maximum intensity in the range of 0° or more and 40° or less is Ib, the angle α that indicates Ib b is 5° or more and 25° or less.

Description

[Technical Field]

[0001] The present invention relates to a coated cutting tool. [Background technology]

[0002] In recent years, with the increasing demand for high-efficiency cutting processes, cutting tools with longer tool life than ever before are required. Therefore, the required properties of tool materials, such as improved wear resistance and chipping resistance, which are related to the life of cutting tools, have become increasingly important. To improve these properties, coated cutting tools, which include a substrate made of cemented carbide, cermet, cubic boron nitride (cBN), or the like, and a coating layer covering the surface thereof, have been widely used.

[0003] As an example of a coated cutting tool, Patent Document 1 describes a coated tool including a substrate and a coating layer disposed on the substrate. Patent Document 1 specifically describes that the coating layer of the coated tool contains cubic crystals containing at least one element selected from the group 4, 5, and 6 elements of the periodic table, Al, Si, B, Y, and Mn, and at least one element selected from the group 1, 2, 3, and 4. Patent Document 1 further describes that the coating layer of the coated tool has, in an X-ray intensity distribution of the α-axis of a pole figure for the (200) plane of the cubic crystals, a first peak located between 15° and 30°, a second peak located between 60° and 75°, and a valley between the first and second peaks where the X-ray intensity is lower than that of the first and second peaks, and the peak intensity of the first peak is 0.7 times or more that of the second peak.

[0004] As an example of a coated cutting tool, Patent Document 2 describes a coated tool including a substrate and a coating layer located on the surface of the substrate. Patent Document 2 specifically describes that the coating layer contains cubic crystals consisting of at least one element selected from among elements of Groups 4a, 5a, and 6a of the periodic table, Al, Si, B, Y, and Mn, and at least one element selected from C and N. Patent Document 2 further describes that in the measurement range of 0° to 90° in the X-ray intensity distribution of the α-axis of a pole figure for the (111) plane of the coating layer of the coated tool, the difference between the maximum and minimum values of X-ray intensity in the α-axis angle range of 30° to 90° is 10% or less of the maximum value. Furthermore, Patent Document 2 describes, as another example, that in the measurement range of 0° to 90° in the X-ray intensity distribution of the α-axis of a pole figure for the (200) plane of the coating layer of the coated tool, the X-ray intensity has maximum and minimum values in the angle range of the α-axis of 0° to 50°, and the difference between the maximum and minimum values is 10% or less of the maximum value. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 146711 [Patent Document 2] International Publication No. 2023 / 162682 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, cutting conditions have become stricter than ever before in order to improve machining efficiency, which has led to a demand for longer tool life.

[0007] However, when machining difficult-to-cut materials such as stainless steel, the workpiece material is likely to adhere to the coated cutting tool and then separate (peel off), resulting in peeling of the coating layer. Furthermore, when such peeling occurs, the peeling can easily lead to breakage of the coated cutting tool. Furthermore, stainless steel undergoes work hardening during machining. Because stainless steel hardens during machining, even if peeling of the coating layer on a coated cutting tool is suppressed, the wear resistance of the coating layer is insufficient. Therefore, it is difficult to extend the tool life, especially when the workpiece material is a difficult-to-cut material such as stainless steel.

[0008] Patent Document 1 describes that a coated cutting tool has high hardness and excellent wear resistance due to the presence of a predetermined coating layer made of cubic crystals. However, the coated cutting tool described in Patent Document 1 has a coating layer that may peel off and has insufficient toughness, making it prone to chipping and fracture, and there is room for improvement in fracture resistance.

[0009] Patent Document 2 describes that the coating layer of the coated tool contains a predetermined cubic crystal, resulting in a homogeneous structure with a uniform crystal orientation. Therefore, Patent Document 2 describes that the coated tool of Patent Document 2 can suppress abnormal wear such as chipping. However, the coated tool of Patent Document 2 leaves room for improvement in wear resistance and / or fracture resistance.

[0010] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a coated cutting tool that has excellent chipping resistance and wear resistance and a long tool life. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention has the following configuration.

[0012] (Configuration 1) Aspect 1 is a coated cutting tool including a substrate and a coating layer formed on the substrate, the coating layer has a compound layer containing a compound having a cubic crystal structure composed of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Al, Si, and B, and at least one element selected from the group consisting of C, N, and O; the compound layer has an average thickness of 0.5 μm or more and 5.0 μm or less, In the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer, when the maximum intensity in the range of 0° to 90° is defined as Ia, the angle α indicating Ia a is more than 40° and less than 60°, In the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer, when the maximum intensity in the range of 0° to 40° is Ib, the angle α indicating Ib b is 5° or more and 25° or less.

[0013] (Configuration 2) In the second configuration, the angle α indicating the Ia of the compound layer a and the angle α indicating the Ib b The difference between (α a -α b 2. The coated cutting tool of claim 1, wherein the angle between the outer circumferential surface and the outer circumferential surface is 20° or more and 40° or less.

[0014] (Configuration 3) A configuration 3 is the coated cutting tool of configuration 1 or 2, wherein the compound layer has an Ib / Ia ratio of 0.5 or greater and less than 1.0.

[0015] (Configuration 4) A configuration 4 is a coated cutting tool according to any one of configurations 1 to 3, wherein, in an X-ray intensity distribution of the α-axis of a pole figure relating to the (200) plane of the cubic crystal of the compound layer, when the maximum intensity in the range of 60° to 90° is Ic, Ic / Ia is 0.5 or more and less than 1.0.

[0016] (Configuration 5) In a fifth aspect, the compound layer has a composition represented by the following formula (1): (Al aM b L 1-a-b )X ···(1) The M is at least one element selected from Ti and Cr, L is at least one element selected from the group consisting of Zr, Hf, V, Nb, Ta, Mo, W, Y, Si, and B; The X is at least one element selected from C, N, and O, The value of a is 0.60 or more and 0.90 or less, The value of b is 0.10 or more and 0.40 or less, 5. The coated cutting tool of any one of configurations 1 to 4, wherein the value of 1-ab is 0.00 or more and 0.20 or less.

[0017] (Configuration 6) A configuration 6 is the coated cutting tool of any one of configurations 1 to 5, wherein the coating layer has an average thickness of 0.5 μm or more and 5.0 μm or less.

[0018] (Configuration 7) Aspect 7 is the coated cutting tool of any one of aspects 1 to 6, wherein the substrate is a cemented carbide, a cermet, a ceramic, or a cubic boron nitride sintered body. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a coated cutting tool having excellent chipping resistance and wear resistance and a long tool life. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a graph showing the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of Invention Product 1. [Figure 2] 10 is a graph showing the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of Comparative Product 5. FIG. [Figure 3] FIG. 1 is a schematic diagram showing the optical system of Schulz's reflection method. [Figure 4] This is a pole figure showing the positions of the α and β angles. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail. Note that the following embodiments are forms for realizing the present invention, and are not intended to limit the scope of the present invention.

[0022] <Coated cutting tools> The coated cutting tool of this embodiment includes a substrate and a coating layer formed on the substrate. Specific examples of the coated cutting tool include indexable cutting inserts for milling or turning, drills, and end mills.

[0023] <Base material> Examples of the substrate of the coated cutting tool of this embodiment include cemented carbide, cermet, ceramics, cubic boron nitride sintered body, diamond sintered body, and high-speed steel. The substrate of the coated cutting tool of this embodiment is preferably cemented carbide, cermet, ceramics, or cubic boron nitride sintered body. Among these, cemented carbide or cermet is more preferred because it has excellent fracture resistance and wear resistance.

[0024] The substrate may have a surface that has been modified. For example, if the substrate is a cemented carbide, a de-β layer may be formed on the surface. If the substrate is a cermet, a surface-hardened layer may be formed. The effects of this embodiment can be achieved even if the surface of the substrate of the coated cutting tool has been modified.

[0025] <Coating layer> The coating layer of the coated cutting tool of this embodiment has a compound layer. In this specification, the coating layer of the coated cutting tool of this embodiment may be referred to as the "coating layer of this embodiment." The coating layer of this embodiment may have a layer other than the compound layer. It is preferable that the coating layer of this embodiment consists of only a compound layer.

[0026] The coated cutting tool of this embodiment includes a coating layer having a predetermined compound layer, so that the coated cutting tool has excellent chipping resistance and wear resistance and a long tool life.

[0027] The compound layer included in the coating layer of this embodiment can be a single compound layer. The compound layer included in the coating layer of this embodiment can be a compound layer with a structure in which multiple types of compound layers with different compositions are laminated. When the compound layer is a compound layer with multiple types of compound layers, the compound layer closest to the substrate may be referred to as the first compound layer, the second compound layer, etc., in this specification. In this specification, the "first compound layer" may be simply referred to as the "first layer." When multiple types of compound layers are laminated, the number of types of compound layers is preferably 1 to 5, and more preferably 1 to 3. Increasing the number of compound layers tends to extend the tool life. On the other hand, if there are too many types of compound layers, the manufacturing cost of the coated cutting tool may be high. When the compound layer is a compound layer with a structure in which multiple types of compound layers with different compositions are laminated, the average thickness of each layer may be, for example, 0.1 μm to 5.0 μm, or 0.2 μm to 3.0 μm.

[0028] The compound layer included in the coating layer of this embodiment may be a compound layer having a structure in which multiple types of compound layers with different compositions are alternately laminated. When the compound layer has a structure in which multiple types of compound layers are alternately laminated, the compound layer closest to the substrate may be referred to as the first compound layer, the second compound layer, etc., in this specification. In this specification, the "first compound layer" may be simply referred to as the "first layer." For example, when the compound layer has a structure in which the first and second layers are alternately laminated, the first and second layers constitute one pair of compound layers, and multiple pairs of compound layers are laminated. The same applies when one pair of compound layers has a structure in which three or more compound layers are included. The number of types of compound layers included in one pair of compound layers is preferably two to five, and more preferably two to three. Increasing the number of compound layers included in one pair of compound layers tends to extend the tool life. On the other hand, if there are too many types of compound layers, the manufacturing cost of the coated cutting tool may increase.

[0029] When the compound layer has a structure in which multiple types of compound layers (one pair of compound layers) with different compositions are alternately laminated, cracks generated during cutting are prevented from propagating toward the substrate, which tends to further improve chipping resistance. When the compound layer has a structure in which multiple types of compound layers with different compositions are alternately laminated, the average thickness per layer is preferably 2 nm to 1500 nm, more preferably 3 nm to 750 nm, and even more preferably 4 nm to 400 nm. When the average thickness per layer is large, it tends to be easier to form a layer with a uniform thickness. On the other hand, when the average thickness per layer is small, excellent adhesion between the layers is achieved, which suppresses peeling of the coating layer, and therefore tends to improve chipping resistance. The number of pairs of compound layers is preferably 2 pairs to 1000 pairs, more preferably 2 pairs to 50 pairs, and even more preferably 2 pairs to 20 pairs.

[0030] The coating layer of the coated cutting tool of this embodiment has a compound layer containing a compound having a cubic crystal structure composed of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Al, Si, and B, and at least one element selected from the group consisting of C, N, and O. The inclusion of the predetermined compound in the compound layer of the coating layer results in excellent fracture resistance and wear resistance.

[0031] The average thickness of the compound layer of this coating layer is 0.5 μm to 5.0 μm, preferably 0.6 μm to 4.8 μm, and more preferably 1.0 μm to 4.2 μm. The average thickness of the compound layer can be determined by measuring three points on a cross section of the coated cutting tool near a position 50 μm from the cutting edge toward the center of the rake face using a scanning electron microscope (SEM) and averaging the values from the three points.

[0032] When the average thickness of the compound layer of the coating layer is 5.0 μm or less, peeling of the coating layer can be suppressed, resulting in excellent chipping resistance. Also, when the average thickness of the compound layer is 0.5 μm or more, excellent wear resistance can be achieved.

[0033] In the compound layer of the coating layer of the coated cutting tool of this embodiment, when the maximum intensity in the range of 0° to 90° in the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer is Ia, the angle α indicating Ia is a is more than 40° and less than 60°, preferably 42° or more and 58° or less, and more preferably 44° or more and 56° or less.

[0034] Figure 1 shows the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of Invention Product 1 in Example 1. In Figure 1, the maximum intensity Ia exists at an angle of 50° within the angle α range of 0° to 90°. Therefore, when the maximum intensity of the coating layer of Invention Product 1 within the angle range of 0° to 90° is defined as Ia, the angle α at which the maximum intensity Ia is shown is a is 50°.

[0035] Figure 2 shows the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of Comparative Product 5. In Figure 2, the maximum intensity Ia is present at an angle of 63° within the angle α range of 0° to 90°. Therefore, when the maximum intensity of the coating layer of Comparative Product 5 within the angle range of 0° to 90° is defined as Ia, the angle α at which the maximum intensity Ia is exhibited is a is 63°.

[0036] Angle α of the compound layer of the coating layer a When the angle α of the compound layer is less than 60°, the toughness of the coating layer is improved, and therefore the fracture resistance is excellent. a When the angle is more than 40°, peeling of the coating layer is suppressed, and therefore, the chipping resistance is excellent.

[0037] In the compound layer of the coating layer of the coated cutting tool of this embodiment, when the maximum intensity in the range of 0° to 40° in the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer is Ib, the angle α indicating Ib is b is 5° or more and 25° or less, preferably 6° or more and 24° or less, and more preferably 8° or more and 23° or less.

[0038] In the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of Invention Product 1 of Example 1 shown in Figure 1, a maximum intensity (maximum value) Ib exists at an angle α of 20° within the angle α range of 0° to 40°. Therefore, when the maximum intensity Ib of the coating layer of Invention Product 1 within the angle range of 0° to 40° is defined as Ib, the angle α at which the maximum intensity Ib is shown is b is 20°.

[0039] In the X-ray intensity distribution of the α axis of the pole figure for the cubic (200) plane of the compound layer of Comparative Product 5 shown in Figure 2, a maximum value exists near 15° in the angle range of 0° to 40°. However, as the angle α increases above 20°, the X-ray intensity monotonically increases, reaching a maximum value at 40°. Therefore, in the case of Comparative Product 5 shown in Figure 2, the X-ray intensity reaches a maximum intensity Ib when the angle α is 40° in the range of 0° to 40°. Therefore, when the maximum intensity in the compound layer of Comparative Product 5 in the range of 0° to 40° is Ib, the angle α at which the maximum intensity Ib is reached is b is 40°.

[0040] Angle α of the compound layer of the coating layer b When the angle α of the compound layer is 25° or less, the hardness of the coating layer is improved, and therefore the wear resistance is excellent. b When the angle is 5° or more, the toughness of the coating layer is improved, resulting in excellent fracture resistance.

[0041] In the compound layer of the coating layer of the coated cutting tool of this embodiment, when the maximum intensity in the range of 0° to 25° in the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer is Id, the angle α indicating Id is d is preferably less than 25°, and the above-mentioned angle α b is less than 40° and angle α d It is preferable that the angle α is less than 25°. d is 25°, there is a high possibility that the X-ray intensity will not have a maximum value in the range of 0° to 25°, for example, in the vicinity of 12°. d is 25° and the angle α b When the angle α is 40°, it is highly likely that the X-ray intensity monotonically increases with increasing angle α in the range of angle α not exceeding 40°. If a compound layer exhibiting such an X-ray intensity distribution is used as the coating layer of a coated cutting tool, it is unlikely that a coated cutting tool having excellent fracture resistance and wear resistance can be obtained.

[0042] The X-ray intensity distribution of the α-axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of the coating layer of this embodiment can be measured by the Schulz reflection method. The Schulz reflection method uses an equiangular reflection optical system, in which the angle of incidence and the angle of reflection are both θ, with 2θ as the diffraction angle, as shown in FIG. 3. Specifically, as shown in FIG. 3, the Schulz reflection method measures the intensity distribution of the diffracted rays by changing the direction of the sample relative to the incident X-rays through α rotation around the A-axis in the sample plane and β rotation (i.e., in-plane rotation) around the normal to the sample plane (B-axis). When the B-axis is on the plane determined by the incident and diffracted rays, the α angle is defined as 90°. When the α angle is 90°, it corresponds to the center point on the pole figure, as shown in FIG. 4. As a specific measurement method, for example, the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer can be measured using a reciprocal lattice space mapping program of an X-ray diffractometer D8 Discover manufactured by Bulker Co., Ltd., according to the following measurement method and analysis conditions. Note that in this specification, the α angle may also be referred to as "angle α."

[0043] [Measurement method (Schulz reflection method)] (1) High-precision goniometer (2) Multipurpose sample stage (3) 2D detector Vantec-500 (4) Target: Cu, Voltage: 50 kV, Current: 1000 μA (5) Micro slit: 1 mm (6) UBC collimator: 0.5 mm

[0044] [Analysis conditions] (1) Fixed 2θ angle: The diffraction angle of the (200) plane of the compound layer used for analysis is the angle at which the diffraction intensity is highest between 42.0° and 44.5°. x When x -0.1° to 2θ x The range was set to +0.1°. (2) Alpha scanning range: 0 to 90 degrees (in 1 degree steps) (3) β fixed angle: 0°

[0045] The α angle showing the maximum intensity can also be read from the contour of the pole figure for the (200) plane. On the other hand, as shown in Figure 1, from the X-ray intensity distribution of the α axis of the pole figure for the (200) plane, the angle α showing the maximum intensity Ia in the range of 0° to 90° can be read. a , and the angle α showing the maximum intensity Ib in the range of 0° to 40° b can be easily obtained.

[0046] In the compound layer of the coating layer of the coated cutting tool of this embodiment, the angle α a and the angle α b The difference between (α a -α b ) is preferably 20° or more and 40° or less, more preferably 23° or more and 39° or less, and even more preferably 25° or more and 38° or less.

[0047] In the compound layer of the coating layer, the angle α a and angle α b The difference between (α a -α b When the difference (α ) is 40° or less, the toughness improves, and the fracture resistance tends to be excellent. a -α b When the angle θ is 20° or more, the effect of suppressing peeling of the coating layer is further enhanced, and therefore, the chipping resistance tends to be excellent.

[0048] In the compound layer of the coating layer of the coated cutting tool of this embodiment, Ib / Ia of the compound layer is preferably 0.5 or more and less than 1.0, and more preferably 0.55 or more and 0.95 or less.

[0049] In the compound layer of the coating layer, when Ib / Ia is less than 1.0, peeling of the coating layer is suppressed, and chipping resistance tends to be excellent. When Ib / Ia is 0.5 or more, the hardness of the coating layer is improved, and wear resistance tends to be excellent.

[0050] In the compound layer of the coating layer of the coated cutting tool of this embodiment, when the maximum intensity Ic is defined as the angle between 60° and 90° in the X-ray intensity distribution of the α-axis of the pole figure for the (200) plane of the cubic crystal of the compound layer, the Ic / Ia of the compound layer is preferably 0.5 or more and less than 1.0, and more preferably 0.55 or more and 0.95 or less.

[0051] When the compound layer of the coating layer has an Ic / Ia ratio of less than 1.0, the toughness of the coating layer is improved, and therefore the coating layer tends to have excellent fracture resistance.When the compound layer has an Ic / Ia ratio of 0.5 or more, the coating layer tends to have excellent wear resistance.

[0052] The compound layer of the coating layer of the coated cutting tool of the embodiment may have a composition represented by the following formula (1). In formula (1), "Al" is aluminum. In formula (1), the symbol X is at least one element selected from carbon (C), nitrogen (N), and oxygen (O). X is preferably at least one element selected from the group consisting of C and N, and more preferably N. The symbols M and L are at least one element selected from a predetermined group of elements described below. (Al a M b L 1-a-b )X ···(1)

[0053] In formula (1) showing the composition of the compound layer of the coating layer, the element represented by the symbol M (M element) is at least one element selected from Ti and Cr.

[0054] When the compound layer contains Ti as the M element in formula (1), the effect of suppressing peeling of the coating layer is further enhanced, and therefore, chipping resistance tends to be excellent.

[0055] When the compound layer contains Cr as the M element in formula (1), the formation of hexagonal crystals in the coating layer is suppressed, and the hardness is improved, which tends to result in excellent wear resistance.

[0056] In formula (1) representing the composition of the compound layer of the coating layer, the element represented by the symbol L (L element) is at least one element selected from the group consisting of Zr, Hf, V, Nb, Ta, Mo, W, Y, Si and B.

[0057] When the compound layer contains Nb, Ta, Mo and / or W as the L element in formula (1), the toughness of the coating layer is improved, and therefore the chipping resistance tends to be excellent.

[0058] When the compound layer contains Si and / or B as the L element in formula (1), the hardness of the coating layer is improved, and therefore the wear resistance tends to be excellent.

[0059] When the compound layer contains Zr, Hf, V and / or Y as the L element in formula (1), the oxidation resistance of the coating layer is improved, and therefore the wear resistance tends to be excellent.

[0060] In formula (1), the value of a, which is the content ratio (atomic ratio) of the Al element to the total of the Al element, the M element, and the L element, is preferably 0.60 or more and 0.90 or less, more preferably 0.70 or more and 0.90 or less, and even more preferably 0.75 or more and 0.90 or less.

[0061] In formula (1), which represents the composition of the compound layer of the coating layer, when the value of a is 0.90 or less, the formation of hexagonal crystals in the coating layer is suppressed, improving hardness and tending to provide excellent wear resistance.In formula (1), when the value of a is 0.60 or more, the coating layer contains a large amount of Al element, improving hardness and oxidation resistance and tending to provide excellent wear resistance.

[0062] In formula (1), the value b, which is the content ratio (atomic ratio) of the M element (Ti and / or Cr element) to the total of the Al element, the M element, and the L element, is preferably 0.05 or more and 0.40 or less, and more preferably 0.10 or more and 0.25 or less.

[0063] In formula (1), when the M element contains Cr, the content ratio (atomic ratio) of the Cr element to the total of the Al element, the M element, and the L element is preferably more than 0.00 and 0.20 or less, and more preferably 0.05 or more and 0.15 or less.

[0064] In formula (1), which represents the composition of the compound layer of the coating layer, when the value of b is 0.40 or less, the coating layer contains a relatively large amount of Al element, which improves hardness and oxidation resistance, and therefore tends to have excellent wear resistance, or when it contains a large amount of L element, which tends to have excellent wear resistance and / or fracture resistance.In formula (1), when the value of b is more than 0.00, peeling of the coating layer is suppressed, and therefore the fracture resistance tends to be excellent.

[0065] In formula (1), the value of 1-ab, which is the content ratio (atomic ratio) of the L element to the total of the Al element, the M element, and the L element, is preferably 0.00 or more and 0.20 or less, more preferably 0.00 or more and 0.15 or less, even more preferably 0.00 or more and 0.10 or less, and still more preferably 0.00.

[0066] In formula (1), which represents the composition of the compound layer of the coating layer, when the value of 1-ab is 0.20 or less, the coating layer contains a relatively large amount of Al element, which improves hardness and oxidation resistance, and therefore tends to have excellent wear resistance, or when the coating layer contains a large amount of Ti element and / or Cr element, which suppresses peeling of the coating layer, which tends to have excellent chipping resistance.In formula (1), when the value of 1-ab is zero (when the L element is not contained), the heat resistance is improved, and therefore the wear resistance tends to be excellent.In formula (1), when the value of 1-ab is greater than zero (when the L element is contained), the wear resistance and / or chipping resistance tend to be excellent.

[0067] In the coated cutting tool of this embodiment, the average overall thickness of the coating layer is preferably 0.5 μm to 5.0 μm, more preferably 0.6 μm to 4.8 μm, and even more preferably 1.0 μm to 4.2 μm. The average thickness of the coating layer can be determined by measuring three locations on a cross section of the coated cutting tool near a position 50 μm from the cutting edge toward the center of the rake face using an SEM and averaging the values at the three locations. When the coating layer consists only of a compound layer, the average overall thickness of the coating layer is the same as the average thickness of the compound layer.

[0068] When the average thickness of the entire coating layer is 5.0 μm or less, peeling of the coating layer is suppressed, and thus chipping resistance tends to be improved.When the average thickness of the entire coating layer is 0.5 μm or more, wear resistance tends to be improved.

[0069] The coated cutting tool of this embodiment has the above-described predetermined coating layer, and thus has excellent chipping resistance and wear resistance, and can have a long tool life.

[0070] In Patent Document 1, when the maximum intensity in the range of 0° to 90° in the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer is defined as Ia, the angle α indicating Ia is a On the other hand, in the coated cutting tool of this embodiment, when the maximum intensity in the range of 0° to 90° in the X-ray intensity distribution of the α axis of the pole figure for the (200) plane is Ia, the angle α indicating Ia is a The coated cutting tool of this embodiment has an angle α a is more than 40°, peeling of the coating layer is suppressed. Therefore, the coated cutting tool has superior fracture resistance compared to the coated tool described in Patent Document 1. In addition, the coated cutting tool of this embodiment has an angle α a When the angle is less than 60°, the toughness of the coating layer is improved, resulting in excellent fracture resistance.

[0071] In Patent Document 2, when the maximum intensity in the range of 0° to 90° in the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer is defined as Ia, the angle α indicating Ia is a is more than 40° and less than 60°, and in the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer, when the maximum intensity in the range of 0° to 40° is Ib, the angle α showing Ib is b On the other hand, the coated cutting tool of this embodiment does not mention that the angle α a is greater than 40° and less than 60°, and the angle α b is 5° or more and 25° or less. Therefore, compared to the coated tool described in Patent Document 2, the coated cutting tool of this embodiment has excellent chipping resistance because peeling of the coating layer is suppressed, or excellent wear resistance because of improved hardness.

[0072] <Method for forming coating layer> The method for forming (manufacturing) the compound layer of the coating layer in the coated cutting tool of this embodiment is not particularly limited. Examples of methods for forming the compound layer include physical vapor deposition methods such as ion plating, arc ion plating, sputtering, and ion mixing. Forming a coating layer using a physical vapor deposition method can form a sharp edge. Therefore, physical vapor deposition is preferred for forming the compound layer. Among these methods, arc ion plating can provide better adhesion between the coating layer and the substrate. Therefore, arc ion plating is more preferred for forming the compound layer.

[0073] The compound layer included in the coating layer of this embodiment can be a compound layer having a structure in which multiple types of compound layers with different compositions are laminated. For example, when the compound layer has a structure in which two compound layers with different compositions are laminated, the compound layer can consist of a first compound layer and a second compound layer. In this case, each of the multiple types of compound layers with different compositions can be formed by the following method. Also, one compound layer (for example, the first compound layer) can be formed in multiple steps.

[0074] <Method of manufacturing a coated cutting tool> The method for manufacturing the coated cutting tool of this embodiment will be described below using a specific example. Note that the method for manufacturing the coated cutting tool of this embodiment is not particularly limited as long as it can achieve the configuration of the coated cutting tool of this embodiment.

[0075] First, the substrate processed into the tool shape is placed in a reaction vessel of a physical vapor deposition apparatus, and a metal evaporation source is installed in the reaction vessel. The element contained in the metal evaporation source is at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Al, Si, and B. Then, the pressure in the reaction vessel is increased to 1.0 × 10 -2 The reactor is evacuated to a vacuum of 100 Pa or less, and the substrate is heated using a heater inside the reactor until its temperature reaches 200°C or higher and 700°C or lower. After heating, Ar gas is introduced into the reactor to set the pressure inside the reactor to 0.5 Pa or higher and 5.0 Pa or lower. In an Ar gas atmosphere with a pressure of 0.5 Pa or higher and 5.0 Pa or lower, a bias voltage of -500 V or higher and -350 V or lower is applied to the substrate, and a current of 40 A or higher and 50 A or lower is passed through the tungsten filament inside the reactor, to perform an ion bombardment treatment using Ar gas on the surface of the substrate. After performing the ion bombardment treatment on the surface of the substrate, the pressure inside the reactor is increased to 1.0 x 10 -2 The vacuum is drawn until the pressure reaches a vacuum of 100 Pa or less.

[0076] When forming the compound layer of the coating layer used in this embodiment, the temperature of the substrate is controlled so that the temperature of the substrate reaches a predetermined starting temperature. After this control, gas is introduced into the reaction vessel to adjust the pressure inside the reaction vessel to 3.0 Pa or more and 8.0 Pa or less. For example, when the compound layer of the coating layer contains carbon (C), the gas to be introduced may be C2H2 gas. When the compound layer of the coating layer contains nitrogen (N), the gas to be introduced may be N2 gas. When the compound layer of the coating layer contains oxygen (O), the gas to be introduced may be O2 gas. When the compound layer of the coating layer contains at least two selected from carbon (C), nitrogen (N), and oxygen (O), the gas to be introduced may be a mixed gas of the above-mentioned gases. For example, when the compound layer of the coating layer contains N and C, the gas to be introduced may be a mixed gas of N2 gas and C2H2 gas.

[0077] For example, when the compound layer of the coating layer contains nitrogen (N) and carbon (C), the volume ratio of the mixed gas is not particularly limited, but may be, for example, N2 gas:C2H2 gas = 95:5 to 85:15.

[0078] When forming a compound layer of the coating layer containing carbon (C), a metal evaporation source containing carbon (C) can be used as needed.

[0079] Next, a bias voltage of -400 V or more and -40 V or less, preferably -350 V or more and -100 V or less, is applied to the substrate, and a metal evaporation source corresponding to the metal and non-metal components of each layer is evaporated by arc discharge with an arc current of 50 A or more and 250 A or less, preferably 80 A or more and 200 A or less, to form a compound layer of the coating layer. At this time, the temperature of the substrate is raised and changed at a constant gradient from a predetermined starting temperature to a predetermined final temperature, and the compound layer of the coating layer can be formed. In this manner, the compound layer can be formed.

[0080] In the method for manufacturing a coated cutting tool according to this embodiment, one compound layer (e.g., the first compound layer) can be formed in multiple steps. In this specification, the number of times a compound layer is formed in multiple steps is referred to as the "number of cycles." Therefore, the above-described compound layer formation can be one or more cycles of forming a predetermined compound layer. When a compound layer is formed in multiple cycles, after the first cycle, the substrate temperature is cooled to a predetermined starting temperature. During this cooling period, the compound layer formation is suspended. Once the substrate temperature reaches the predetermined starting temperature, the next second cycle of film formation is initiated. At this time, the compound layer in the second cycle can be formed by increasing the substrate temperature and changing the substrate temperature at a constant gradient from the predetermined starting temperature to the predetermined final temperature, as in the first cycle described above. By repeating the above procedure, a predetermined number of compound layers can be formed.

[0081] When the compound layer has a structure in which two compound layers with different compositions are laminated, the first compound layer can be formed for a predetermined number of cycles, and then the second compound layer can be formed for a predetermined number of cycles in the same procedure as for the first layer. The same applies to a compound layer having a structure in which three or more compound layers with different compositions are laminated.

[0082] The starting temperature when forming the compound layer of the coating layer is preferably 100° C. or higher and 300° C. or lower, more preferably 120° C. or higher and 280° C. or lower, and even more preferably 150° C. or higher and 250° C. or lower. When multiple film formation cycles are performed to form one layer, the starting temperature for each cycle is preferably the same.

[0083] The temperature reached when forming the compound layer of the coating layer is higher than the above-mentioned starting temperature. The temperature reached is preferably 200° C. or higher and 400° C. or lower, more preferably 220° C. or higher and 380° C. or lower, and even more preferably 250° C. or higher and 350° C. or lower. When multiple film formation cycles are performed to form one layer, the temperature reached in each cycle is preferably the same.

[0084] When forming the compound layer of the coating layer, the thickness of the compound layer formed from a predetermined starting temperature to a predetermined reached temperature (thickness of the compound layer in one cycle) is preferably 10 nm to 800 nm, more preferably 50 nm to 500 nm, and even more preferably 100 nm to 400 nm. When multiple cycles of film formation are performed to form one layer, the thickness of the compound layer in each cycle is preferably the same.

[0085] The number of cycles (number of film formations) when forming one layer of a predetermined composition of the compound layer of the coating layer is preferably 1 to 60 cycles, more preferably 2 to 55 cycles.

[0086] When the compound layer of the coating layer consists of two compound layers (first and second layers) with different compositions, an alternating laminate structure can be formed in which the first and second layers are alternately stacked in two or more layers. In this case, the first layer is formed under the film formation conditions for the first layer, and the second layer is formed under the film formation conditions for the second layer. Each layer can be formed alternately by alternately evaporating a metal evaporation source corresponding to the metal components of the first layer and a metal evaporation source corresponding to the metal components of the second layer by arc discharge under predetermined conditions. The thickness of each layer constituting the alternating laminate structure can be controlled by adjusting the metal evaporation source, starting temperature, and final temperature corresponding to the metal components of the first layer and the metal evaporation source, starting temperature, and final temperature corresponding to the metal components of the second layer, respectively.

[0087] In the coated cutting tool of this embodiment, the X-ray intensity distribution of the compound layer can be adjusted to a predetermined shape by controlling manufacturing parameters such as pressure, starting temperature, final temperature, thickness per cycle, and composition of the compound layer in the step of forming the compound layer. The influence of each manufacturing parameter on the compound layer will be described below.

[0088] When forming the compound layer, the pressure is increased to increase the angle α bThe angle α a and the angle α b The difference between (α a -α b ) can be made smaller.

[0089] When forming the compound layer, the angle α indicating Ia can be increased by increasing the starting temperature. a , Ib indicates the angle α b , and Ib / Ia can be increased.

[0090] When forming the compound layer, the angle α a , and angle α indicating Ia a and the angle α b The difference between (α a -α b In addition, when the maximum intensity in the range of 60° to 90° in the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer is defined as Ic, the ratio Ic / Ia can be increased by increasing the ultimate temperature.

[0091] When forming the compound layer, by increasing the thickness per cycle, Ib / Ia can be reduced and Ic / Ia can be increased.

[0092] When forming the compound layer, by increasing the content ratio of Al (the value of a in formula (1), the atomic ratio) in the composition of the compound layer of formula (1), the angle α a , Ib indicates the angle α b , and Ic / Ia can be increased.

[0093] When forming the compound layer, if Cr is contained as the M element in the composition of the compound layer of formula (1), the angle α indicating Ib can be increased by increasing the content ratio of Cr (the value of b in formula (1), the atomic ratio). b The angle α a and the angle α b The difference between (α a -αb ) can be made smaller.

[0094] The thickness of each layer constituting the coating layer of the coated cutting tool of this embodiment can be measured from the cross-sectional structure of the coated cutting tool using an optical microscope, a scanning electron microscope (SEM), a transmission electron microscope (TEM), etc. The average thickness of each layer of the coated cutting tool of this embodiment can be determined by measuring the thickness of each layer from three or more cross sections located 50 μm from the cutting edge ridge of the surface facing the metal evaporation source toward the center of the surface, and calculating the average value (arithmetic mean value) of the measurements.

[0095] Furthermore, the composition of each layer constituting the coating layer in the coated cutting tool of this embodiment can be measured from the cross-sectional structure of the coated cutting tool of this embodiment using an energy dispersive X-ray analyzer (EDS) or a wavelength dispersive X-ray analyzer (WDS), for example. [Example]

[0096] The present invention will be specifically described below using examples, but the present invention is not limited thereto. In the following examples, the coating layer does not include any layer other than the compound layer. Therefore, the compound layer may be referred to as the coating layer.

[0097] Example 1 Samples of invention products 1 to 25 were prepared as Example 1. Furthermore, comparative products 1 to 14 were prepared as comparative examples (comparative example 1) for invention products 1 to 25.

[0098] <Manufacturing method> A cemented carbide alloy having a composition of 94.7% WC-5.0% Co-0.3% Cr3C2 (all mass %), machined into the shape of an insert from CNMG120408-SM (manufactured by Tungaloy Corporation), was prepared as the substrate for Invention Products 1-25 and Comparative Products 1-14. A metal evaporation source was placed in the reaction chamber of an arc ion plating device so as to obtain the compound layer composition shown in Table 1. The prepared substrate was fixed to a fixture on a rotary table inside the reaction chamber.

[0099] Then, the pressure in the reaction vessel was increased to 5.0 × 10 -3 The reactor was evacuated to a vacuum of 100 Pa or less. After evacuating, the substrate was heated using a heater inside the reactor until the temperature reached 450°C. After heating, Ar gas was introduced into the reactor so that the pressure was 2.7 Pa. The substrate was heated until its temperature reached the starting temperature shown in Table 2.

[0100] In an Ar gas atmosphere at a pressure of 2.7 Pa, a bias voltage of -400 V was applied to the substrate, and a current of 40 A was passed through the tungsten filament in the reaction vessel, and ion bombardment treatment with Ar gas was performed on the surface of the substrate for 30 minutes. After the ion bombardment treatment was completed, the pressure in the reaction vessel was increased to 5.0 × 10 -3 The vacuum was drawn until the vacuum reached 0.1 Pa or less.

[0101] Next, a first-cycle compound layer was formed on the surface of the substrate of Invention Products 1 to 25 and Comparative Products 1 to 14. Specifically, after evacuation, the temperature of the substrate was controlled to the starting temperature shown in Table 2. Nitrogen gas (N2) was introduced into the reaction vessel, and the pressure inside the reaction vessel was adjusted to the pressure shown in Table 2. Then, a bias voltage shown in Table 2 was applied to the substrate, and the metal evaporation source for the compound layer having the composition shown in Table 1 was evaporated by arc discharge with the arc current shown in Table 2, forming a first-cycle compound layer on the surface of the substrate. During compound layer formation, the pressure inside the reaction vessel was controlled to be as shown in Table 2. The arc discharge time for each cycle was adjusted to control the thickness of the compound layer in the first cycle to be the thickness shown in the "Thickness per Cycle" column in Table 2. The compound layer was formed while the temperature of the substrate was changed at a constant gradient so that the temperature of the substrate was the starting temperature shown in the "Start Temperature" column of Table 2 at the start of compound layer formation in the first cycle and the reaching temperature shown in the "Attained Temperature" column of Table 2 at the end of compound layer formation in the first cycle. In this manner, a compound layer was formed on the surface of the substrate in the first cycle.

[0102] The formation of the compound layer was repeated the number of times indicated in the "Number of Cycles" column of Table 2. After forming the first-cycle compound layer on the surface of the substrate, the temperature of the substrate was cooled to the starting temperature shown in Table 2. Then, the second-cycle compound layer was formed on the surface of the substrate in the same manner as the above-described first-cycle compound layer formation process. By repeating this process the number of times indicated in the "Number of Cycles" column of Table 2, a compound layer with a predetermined number of cycles was formed.

[0103] As shown in Table 2, the "starting temperature" and "arrival temperature" of Comparative Products 4 and 5 are the same. In this case, the temperature of the substrate when forming the compound layer was kept constant, and the entire compound layer was formed in one cycle.

[0104] When forming the compound layers of Invention Products 1 to 25, Comparative Products 1 to 3, and 6 to 14, the film-forming conditions for a predetermined number of cycles were all made the same. Therefore, the film-forming time for each cycle when forming the respective compound layers of Invention Products 1 to 25, Comparative Products 1 to 3, and 6 to 14 is constant.

[0105] After forming the compound layer on the surface of the substrate to the predetermined number of cycles and the predetermined average thickness shown in Table 2, the power of the heater was turned off, and after the sample temperature dropped below 100°C, the sample was taken out from the reaction vessel.

[0106] As described above, the coated cutting tools of Invention Products 1 to 25 and Comparative Products 1 to 14 were manufactured.

[0107] <Measurement of the Average Thickness of the Compound Layer> For the average thickness of the compound layer of each invention product and comparative product, a cross-section in the vicinity of a position 50 μm from the cutting edge of the coated cutting tool toward the center of the rake face was measured at three locations by SEM, and the average value of the three locations was taken as the average thickness. Table 1 shows the average thickness of the compound layer of each invention product and comparative product. Also, Table 2 shows the thickness per cycle of the coating layer. The value described in the "Thickness per Cycle" column of Table 2 is the value obtained by dividing the average thickness of the entire compound layer by the number of cycles.

[0108] <Measurement of the X-ray Intensity Distribution> The obtained samples were subjected to X-ray diffraction measurements using the 2θ / θ method using a Bluker D8 Discoer X-ray diffractometer. The measurement conditions were a tube voltage of 50 kV, a tube current of 1000 μA, a CuKα X-ray source, a 1 mm microslit, a 0.5 mm UBC collimator, and a 2θ measurement range of 10° to 140°. The crystal structure of the compound in the compound layer (coating layer) of all samples was confirmed to be a cubic NaCl-type structure. Furthermore, the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer was measured using the measurement method and analysis conditions described below.

[0109] [Measurement method (Schulz reflection method)] (1) High-precision goniometer (2) Multipurpose sample stage (3) 2D detector Vantec-500 (4) Target: Cu, Voltage: 50 kV, Current: 1000 μA (5) Micro slit: 1 mm (6) UBC collimator: 0.5 mm

[0110] [Analysis conditions] (1) Fixed 2θ angle: The diffraction angle of the (200) plane of the cubic crystal of the compound layer used for analysis is the angle at which the diffraction intensity is highest between 42.0° and 44.5°. x When x -0.1° to 2θ x The range was set to +0.1°. (2) α scanning range: 0° to 90° (1° step) (3) β fixed angle: 0°

[0111] Based on the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of each sample measured as described above, the maximum intensity Ia in the range of 0° to 90° and the angle α at which Ia is a , the maximum intensity Ib in the α angle range of 0° to 40°, the angle α showing Ib b , the maximum intensity Ic in the range of α angle of 60° to 90°, the maximum intensity Id in the range of 0° to 25°, and the angle α at which Id isd The value of the angle α a , Ib indicates the angle α b , and the angle α indicating Id d The values of the angle α for each sample in Example 1 are shown in Table 3. a and angle α b The difference between (α a -α b ), the ratio of Ia to Ib (Ib / Ia), and the ratio of Ia to Ic (Ic / Ia).

[0112] <Measurement of the composition of each layer> The composition of the compound layer of each of the inventive and comparative products in Example 1 was measured by measuring the cross section of a specific layer of the coated cutting tool using an energy dispersive X-ray spectrometer (EDS). The crystal system of the compound layer was identified by X-ray diffraction measurement using a 2θ / θ focusing optical system. Table 1 shows the composition of the compound layer of each of the inventive and comparative products (types and content ratios (atomic ratios) of elements contained in each layer).

[0113] <Cutting test> A cutting test was carried out on the coated cutting tools of the invention and the comparative example of Example 1, and the chipping resistance (tool life) was evaluated.

[0114] The cutting test conditions are as follows: [Cutting test conditions] Work material: SUS329J4L Workpiece shape: Round bar with two equally spaced grooves on the outer surface Cutting speed: 150m / min Cutting depth: 0.5 mm Feed: 0.2mm / rev Coolant: Water-soluble coolant Evaluation items: The tool life was defined as the machining time until the tool flank wear width exceeded 0.3 mm or the cutting edge was chipped, and the machining time until the tool life was reached was measured. In addition, the form of damage at the end of the tool life was observed using an SEM.

[0115] Table 4 shows the results of the cutting test of the invention product and the comparative product of Example 1.

[0116] Example 2 As Example 2, samples of invention products 26 to 31 were prepared. In Example 2, multiple types of compound layers were laminated as the coating layer. As shown in Table 7, invention products 26 and invention products 28 to 31 had a coating layer consisting of two types of compound layers (first layer and second layer). Invention product 27 had a coating layer consisting of three types of compound layers (first layer, second layer, and third layer).

[0117] As shown in Table 5, in Example 2, compound layers of six types A to F were used. The method for measuring the composition of the compound layer of each invention product in Example 2 was the same as the method for measuring the composition of the compound layer of the sample in Example 1.

[0118] Table 6 shows the film formation conditions for the compound layers of types A to F. The compound layers of types A to F were formed according to the conditions shown in Table 6 in the same manner as the compound layer of the sample of Example 1 was formed.

[0119] The "Type" column in Tables 7 and 8 indicates which of Types A to F in Table 5 the compound layers (first, second and third layers) used in Inventions 26 to 31 correspond to.

[0120] The first layer of Invention Products 26-29 is the compound layer closest to the substrate. In Invention Products 26-29, the second layer was formed after the first layer was formed. In Invention Product 27, the third layer was further formed after the second layer was formed. For Invention Products 26-29, the "Average Thickness" column in Table 7 shows the average thickness of each compound layer (first layer, second layer, or third layer). For example, in Invention Product 26, the average thickness of the entire first layer formed in 4 cycles was 0.7 μm, and the average thickness of the entire second layer formed in 14 cycles was 2.8 μm.

[0121] In invention product 30 shown in Table 8, a compound layer was formed by alternately repeating six times (six pairs) a first layer formed in two cycles and a second layer formed in one cycle. For invention product 30, the "Number of cycles per pair" and "Average thickness per pair" columns in Table 8 show the number of cycles and average thickness per pair of each compound layer (first layer or second layer). For example, in invention product 30, a first layer was formed twice per pair, with an average thickness of 0.35 μm per pair, and a second layer was formed once per pair, with an average thickness of 0.2 μm per pair. The combined average thickness of the first and second compound layers per pair was 0.55 μm (= 0.35 μm + 0.2 μm), and the average thickness of the entire six pairs of compound layers was 3.3 μm (= 0.55 μm × 6 pairs).

[0122] In invention product 31 shown in Table 8, a compound layer was formed by alternately repeating 15 times (15 pairs) a first layer formed in one cycle and a second layer formed in one cycle. For example, in invention product 31, a first layer with one cycle per pair and an average thickness of 0.2 μm and a second layer with one cycle per pair and an average thickness of 0.06 μm were alternately formed, and the total average thickness of the first and second layers per pair was 0.26 μm (= 0.2 μm + 0.06 μm), and the average thickness of the entire compound layer for a total of 15 pairs was 3.9 μm (= 0.26 μm × 15 pairs).

[0123] The average thickness of the entire compound layer (first and second layers, or first to third layers) is shown in the "Average Thickness of the Entire Compound Layer" column in Tables 7 and 8. The method for measuring the average thickness of the compound layer in the sample of Example 2 was the same as that in the sample of Example 1.

[0124] The X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of the invention of Example 2 was measured under the same conditions as in Example 1. Based on the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer of each sample, the maximum intensity Ia in the range of 0° to 90° and the angle α showing Ia were calculated. a, the maximum intensity Ib in the α angle range of 0° to 40°, the angle α showing Ib b , the maximum intensity Ic in the range of α angle of 60° to 90°, the maximum intensity Id in the range of 0° to 25°, and the angle α at which Id is d The value of the angle α a , Ib indicates the angle α b , and the angle α indicating Id d In addition, Table 9 shows the values of the angle α a and angle α b The difference between (α a -α b ), the ratio of Ia to Ib (Ib / Ia), and the ratio of Ia to Ic (Ic / Ia).

[0125] As in Example 1, a cutting test was conducted on the coated cutting tool of the invention in Example 2 to evaluate the tool life. Table 10 shows the results of the cutting test on the invention in Example 2.

[0126] <Evaluation of cutting test> In the cutting tests of Examples 1 and 2, the tool life of the inventive product of this embodiment was 12 minutes or more, which was longer than the tool life of all the comparative products. Therefore, it can be said that the inventive product of this embodiment is a coated cutting tool with excellent chipping resistance and wear resistance and a long tool life.

[0127] On the other hand, in the cutting test of Example 1, all of the comparative products had a tool life of 10 minutes or less. Furthermore, in the cutting test, the damage form at the end of the tool life of comparative products 1 to 5, 7, 8, 10 to 12, and 14 was chipping.

[0128] From the above, it is clear that the coated cutting tool of this embodiment has excellent chipping resistance and wear resistance, and is a coated cutting tool with a long tool life.

[0129] [Table 1]

[0130]

Table 2

[0131]

Table 3

[0132]

Table 4

[0133]

Table 5

[0134]

Table 6

[0135]

Table 7

[0136]

Table 8

[0137]

Table 9

[0138]

Table 10

Claims

1. A coated cutting tool comprising a substrate and a coating layer formed on the substrate, the coating layer has a compound layer containing a compound having a cubic crystal structure composed of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Y, Al, Si, and B, and at least one element selected from the group consisting of C, N, and O; the compound layer has an average thickness of 0.5 μm or more and 5.0 μm or less, In the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer, when the maximum intensity in the range of 0° to 90° is defined as Ia, the angle α indicating Ia ａ is more than 40° and less than 60°, In the X-ray intensity distribution of the α axis of the pole figure for the (200) plane of the cubic crystal of the compound layer, when the maximum intensity in the range of 0° to 40° is Ib, the angle α indicating Ib is ｂ is 5° or more and 25° or less.

2. The angle α indicating the Ia of the compound layer ａ and the angle α indicating the Ib ｂ The difference between ａ -α ｂ 2. The coated cutting tool according to claim 1, wherein the angle between the first and second poles is 20° or greater and 40° or less.

3. 3. The coated cutting tool according to claim 1, wherein the compound layer has a ratio Ib / Ia of 0.5 or more and less than 1.

0.

4. 3. The coated cutting tool according to claim 1, wherein, in an X-ray intensity distribution of an α-axis of a pole figure for a (200) plane of the cubic crystal of the compound layer, when a maximum intensity in a range of 60° to 90° is defined as Ic, Ic / Ia is 0.5 or more and less than 1.

0.

5. The compound layer has a composition represented by the following formula (1): (Al) ａ M ｂ L １－ａ－ｂ )X・・・(1) The M is at least one element selected from Ti and Cr, L is at least one element selected from the group consisting of Zr, Hf, V, Nb, Ta, Mo, W, Y, Si, and B; X is at least one element selected from the group consisting of C, N, and O, the value of a is 0.60 or more and 0.90 or less, the value of b is 0.05 or more and 0.40 or less, 3. The coated cutting tool according to claim 1, wherein the value of 1-a-b is equal to or greater than 0.00 and equal to or less than 0.

20.

6. 3. The coated cutting tool according to claim 1, wherein the coating layer has an average thickness of 0.5 μm or more and 5.0 μm or less.

7. 3. The coated cutting tool according to claim 1, wherein the substrate is made of cemented carbide, cermet, ceramics or cubic boron nitride sintered body.

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