Coated cutting tool and cutting tool having the same

Abstract

The inner wall (17) of the through-hole (15) of the base (3) of the coated tool (1) of the present disclosure has a binder phase-rich layer (19) in which the content of the binder phase is higher than in the interior of the base (3). The thickness T1 of the binder phase-rich layer (19) in the central portion is thicker than the thickness T2 of the binder phase-rich layer (19) in the end portion of the inner wall (17). The coating (30) has a first layer (31) containing a titanium compound and a second layer (32) containing alumina. In a cross-section polished surface of the through-hole (15), when the inclination angle of the normal line of the {112} plane, which is a crystal plane of the crystal grains of the first layer (31), with respect to the normal line of the surface of the first layer (31) is measured, in a distribution diagram of the inclination angle degrees obtained by dividing the measured inclination angle in the range of 0° or more and 45° or less by 0.25°, the highest peak exists in the range of 0° or more and 10° or less, and the total degrees existing in the range of 0° or more and 10° or less accounts for 45% or more and 60% or less of the total degrees in the distribution diagram of the inclination angle degrees.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a coated cutting tool used in cutting processing and a cutting tool provided with the coated cutting tool. BACKGROUND

[0002] Currently, as a base of a cutting tool, a wear-resistant member, a sliding member, and the like, which requires wear resistance, sliding properties, and chipping resistance, a cermet in which titanium (Ti) is a main component is widely used.

[0003] For example, in Patent Literature 1, a surface-coated titanium carbonitride-based cermet cutting insert having a mounting through-hole mounted to a cutting tool body is described. In Patent Literature 1, it is described that a metal exuded layer is provided to an inner surface of the mounting through-hole in order to provide an insert in which abnormal damage is less even in cutting with high load.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Publication No. 2012-245581 SUMMARY

[0007] The coated cutting tool of the present disclosure is a coated cutting tool provided with a base of a cermet containing hard particles and a binder phase, and a coating layer on the base. The coated cutting tool has a first surface, a second surface, a cutting edge at at least a part of a ridge line of the first surface and the second surface, a third surface on the opposite side of the first surface, and a through-hole passing through from the first surface to the third surface. An inner wall constituting the through-hole has, at least in a central portion, a binder phase-rich layer in which the content rate of the binder phase is higher than in the inside of the base. The thickness T1 of the binder phase-rich layer of the central portion is thicker than the thickness T2 of the binder phase-rich layer of an end portion of the inner wall. The coating layer has a first layer containing a titanium compound, and a second layer containing alumina, which is located on the first layer in a contiguous manner. In a cross-section polishing surface of the through-hole, when an inclination angle is measured with respect to a normal line of a surface of the first layer, of a crystal plane, that is, a {112} plane, of a crystal grain of the first layer, the highest peak exists in a range of 0° or more and 10° or less in an inclination angle degree distribution chart in which the measured inclination angles in a range of 0° or more and 45° or less are divided at intervals of 0.25° and degrees existing in each division are summarized, and the total of the degrees in the range of 0° or more and 10° or less accounts for a proportion of 45% or more and 60% or less of the total degrees in the inclination angle degree distribution chart. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a perspective view showing an example of the coated cutting tool of the present disclosure.

[0009] Figure 2 is a schematic diagram of a cross section showing an example of the coated tool of the present disclosure.

[0010] Figure 3 is an enlarged schematic diagram of a cross section of the coated tool of the present disclosure.

[0011] Figure 4 is an enlarged schematic diagram of a cross section of another example of the coated tool of the present disclosure.

[0012] Figure 5 is an enlarged schematic diagram of a cross section of another example of the coated tool of the present disclosure.

[0013] Figure 6 is a schematic enlarged view of a coating layer possessed by the coated tool of the present disclosure.

[0014] Figure 7 is a plan view showing an example of the cutting tool of the present disclosure.

[0015] Figure 8 is an enlarged schematic diagram of a cross section of the coated tool of the cutting tool of the present disclosure. DETAILED DESCRIPTION

[0016] <Coated tool>

[0017] Hereinafter, the coated tool of the present disclosure will be described in detail using the drawings. However, in each of the drawings referred to below, only the main components necessary in the aspect of explaining the embodiments are simply shown for the sake of convenience of explanation. Thus, the coated tool of the present disclosure can be provided with any constituting components not shown in each of the drawings referred to. In addition, the dimensions of the components in each of the drawings do not faithfully show the dimensions of the actual constituting components and the dimensional ratios of the components, and the like. These points are also the same in the cutting tool described later.

[0018] In the coated tool for cutting processing, it is desirable to have less abnormal damage. The present disclosure provides a coated tool having less abnormal damage and a cutting tool provided with the coated tool.

[0019] The coated tool of the present disclosure has a substrate of cermet containing hard particles and a binder phase. The hard particles are, for example, TiCN, TiC, TiN, (TiM)CN (M is one or more selected from W, Nb, Ta, Mo, V). The binder phase has an iron group metal such as Ni or Co as a main component. Note that the main component means 50% by mass or more in the constituting components.

[0020] As shown in Figure 1 , 2 , the shape of the coated tool 1 of the present disclosure can be, for example, a quadrilateral plate shape. Figure 1The upper surface, i.e., the first surface 5, in the coating tool 1 is a so-called rake surface. In addition, the coating tool 1 has a side surface, i.e., a second surface 7, which is continuous with the first surface 5.

[0021] The coating tool 1 has a lower surface, i.e., a third surface 9, which is located on the opposite side of the first surface 5. The second surface 7 is continuous with the first surface 5 and the third surface 9, respectively.

[0022] The coating tool 1 of the present disclosure has a cutting edge 11 located at at least a portion of an edge line where the first surface 5 and the second surface 7 intersect. In other words, the coating tool 1 of the present disclosure has a cutting edge 11 located at at least a portion of an edge line where the rake surface and the flank surface intersect. The cutting edge 11 has a fourth surface which is continuous with the first surface 5 and the second surface 7. The fourth surface can be a C surface (chamfered surface) which is obtained by chamfering the corner of the first surface 5 and the second surface 7. In addition, the fourth surface can also be an R surface (rounded surface) which is obtained by rounding the corner of the first surface 5 and the second surface 7.

[0023] In the coating tool 1, the entire outer periphery of the first surface 5 can become the cutting edge 11, but the coating tool 1 is not limited to this structure, and for example, only one side of the quadrilateral rake surface, in other words, only one of the four fourth surfaces can have the cutting edge 11.

[0024] The coating tool 1 of the present disclosure has a through-hole 15 which penetrates the base 3 from the first surface 5 to the third surface 9. As shown in FIG. 1, in the inner wall 17 which constitutes the through-hole 15, there is a binder phase-rich layer 19 in at least the central portion 17a. The binder phase-rich layer 19 is a region which contains hard particles and a binder phase and in which the content rate of the binder phase is higher than in the inside of the base 3. The inside of the base 3 refers to a portion which is 500 μm or more from the surface of the base 3. The binder phase-rich layer 19 does not need to exist in the entire inner wall 17 of the through-hole 15, but can exist in at least the central portion 17a. Figure 3

[0025] The central portion 17a is a portion which is at the center when the through-hole 15 is divided into nine equal parts in the depth direction. In addition, the end portion 17b is an end portion when the through-hole 15 is divided into nine equal parts in the depth direction.

[0026] As shown in FIG. 1, in the coating tool 1 of the present disclosure, the thickness T1 of the binder phase-rich layer 19 of the central portion 17a of the inner wall 17 which constitutes the through-hole 15 is thicker than the thickness T2 of the binder phase-rich layer 19 of the end portion 17b of the inner wall 17 which constitutes the through-hole 15. The thickness T1 of the binder phase-rich layer 19 of the central portion 17a and the thickness T2 of the binder phase-rich layer 19 of the end portion 17b are each an average value. It is preferable to measure the thickness T1 and the thickness T2 by observing the cross section of the coating tool 1 using a metal microscope or an electron microscope. Note that the binder phase-rich layer 19 can not exist in the end portion 17b. Figure 3 In the coating tool 1 of the present disclosure, the thickness T1 of the binder phase-rich layer 19 of the central portion 17a of the inner wall 17 which constitutes the through-hole 15 is thicker than the thickness T2 of the binder phase-rich layer 19 of the end portion 17b of the inner wall 17 which constitutes the through-hole 15. The thickness T1 of the binder phase-rich layer 19 of the central portion 17a and the thickness T2 of the binder phase-rich layer 19 of the end portion 17b are each an average value. It is preferable to measure the thickness T1 and the thickness T2 by observing the cross section of the coating tool 1 using a metal microscope or an electron microscope. Note that the binder phase-rich layer 19 can not exist in the end portion 17b.​

[0027] In the coated tool 1 of the present disclosure, by having such a structure, the case where the coated tool 1 is abnormally damaged starting from the inner wall 17 to which a large force is applied when fixed to a shank (not shown) is suppressed.

[0028] Figure 6 is a schematic enlarged view of the coating of the coated tool 1 of the present disclosure. As shown, the coated tool 1 has a coating 30. Figure 6

[0029] The coating 30 is located on at least the binder phase-rich layer 19. The coating 30 can be located on the first face 5, and in addition, on other faces than the first face 5 in the base 3. The coating 30 improves the properties of the coated tool 1 in cutting processing, such as wear resistance and chipping resistance.

[0030] The coating 30 has a first layer 31 and a second layer 32. The first layer 31 is located on the first face 5 and contains cubic titanium carbonitride. In addition, the second layer 32 is located on the first layer 31 in a manner of being in contact. The second layer 32 can contain, for example, alumina (AI2O3).

[0031] A titanium nitride layer 33 can be present between the first layer 31 and the base 3. If such a structure is present, the adhesion of the base 3 and the first layer 31 is high.

[0032] The first layer 31 has a titanium carbonitride layer 34. In the first layer 31, in addition to titanium carbonitride, for example, titanium carbide, nitride, oxide, oxycarbide, and oxycarbonitride can be contained. In addition, the first layer 31 can be a single-layer structure as long as it contains cubic titanium carbonitride, and in addition, it can be a structure in which a plurality of layers are stacked.

[0033] The main components of the titanium nitride layer 33 and the titanium carbonitride layer 34 are titanium nitride and titanium carbonitride, respectively. The "main component" refers to a component having the largest value in mass% compared to other components. The titanium nitride layer 33 and the titanium carbonitride layer 34 can contain components other than titanium nitride and titanium carbonitride, respectively.

[0034] The coating 30 can be composed of only the first layer 31 and the second layer 32, and in addition, it can have layers other than these layers. For example, another layer can be present between the base 3 and the first layer 31, and in addition, another layer can be present on the second layer 32.

[0035] The first layer 31 is located on the binder phase-rich layer 19. The first layer 31 has a portion having a higher hardness than the binder phase-rich layer 19. If such a structure is present, the wear resistance in the clamping portion is increased. The first layer 31 can be formed by a CVD method or a PVD method.

[0036] ​The first layer 31 shows a tilt angle distribution chart in which, when the tilt angle of the normal line of the {112} plane, which is a crystal plane of the crystal grains, with respect to the normal line of the surface is measured, the highest peak of the measured tilt angle is present in the tilt angle division range of 0 degrees or more and less than 10 degrees and the total proportion of the degrees present in the tilt angle division of 0 degrees or more and less than 10 degrees is 45% or more and 60% or less of the total degrees in the tilt angle distribution chart.

[0037] If the total proportion of the degrees present in the tilt angle division of 0 degrees or more and less than 10 degrees is 45% or more and 60% or less of the total degrees in the tilt angle distribution chart, the hardness of the coating layer 30 increases. Thus, in this case, the coating tool 1 is configured such that the layer (the coating layer 30) having a relatively high hardness is disposed in the surface layer portion and the layer (the binder phase-rich layer 19) having a relatively low hardness is disposed at a position deeper than the coating layer 30. By so configuring, when the coating tool 1 is fixed to the shank 105 by the chuck 107, the force applied to the local portion of the substrate 3 is small in the contact between the central portion 17a of the inner wall 17 and the chuck 107 due to the suppressed deformation of the binder phase-rich layer 19 in the central portion 17a, and thus the coating tool 1 is less likely to be broken and abnormal damage is less likely to occur.

[0038] In the measurement of the tilt angle described above, for example, a backscattered electron diffraction (EBSD) method can be used. An example of the measurement using the backscattered electron diffraction method is shown below.

[0039] First, the coating tool 1 is cut so as to expose the coating layer 30 in a manner that a cross section of the through hole 15 is visualized. Next, a surface on which the first layer 31 is exposed is subjected to polishing processing to smooth the surface, and ion milling processing is performed on the measurement site.

[0040] The first layer 31 thus exposed is irradiated with an electron beam, and the tilt angle of the normal line of the {112} plane is measured at intervals of 0.1 μm in a range of about 40 x 25 μm 2 Next, the measured tilt angles in the range of 0 degrees or more and less than 45 degrees are preferably divided at intervals of 0.25 degrees.

[0041] As examples of the second layer 32 containing alumina, α-alumina (α-Al203), γ-alumina (γ-Al203), and κ-alumina (κ-Al203), and the like can be given. In the case where the second layer 32 contains α-alumina among these, the heat resistance of the coating tool 1 can be improved. The second layer 32 can be a structure containing only one of the above-described compounds, or can be a structure containing a plurality of the above-described compounds.

[0042] The alumina contained in the second layer 32 is one of the above-described compounds, and can be evaluated, for example, by performing X-ray diffraction (XRD) analysis and observing the distribution of peaks.

[0043] The first layer 31 can contain components other than titanium carbonitride. Also, the second layer 32 can contain components other than alumina. For example, the first layer 31 can also contain alumina. Also, the second layer 32 can contain titanium compounds such as titanium carbonitride. In this case, the adhesion of the first layer 31 and the second layer 32 is improved.

[0044] The hardness of the binder phase-enriched layer 19 is lower than that of the base 3, and the hardness of the binder phase-enriched layer 19 is higher than that of the metal exudation layer described in Patent Document 1. Therefore, the deformation of the binder phase-enriched layer 19 is suppressed compared to the metal exudation layer.

[0045] Due to the above-described structure, when the coated tool 1 is fixed to a tool shank using a chucking member, the force applied to the local part of the base 3 is small due to the suppressed deformation of the binder phase-enriched layer 19 of the central part 17a in contact with the chucking member, and thus the coated tool 1 is less likely to break, and abnormal damage is less likely to occur.

[0046] The size of the coated tool 1 is not particularly limited, and for example, the length of one side of the rake face is set to about 3 to 20 mm. Also, the thickness of the coated tool 1 is set to, for example, about 1 to 20 mm. Also, in the Figure 1 In the above-described embodiment, the coated tool 1 is exemplified as a quadrangular shape, but can be, for example, a triangular shape or a disc shape.

[0047] Also, as shown in Figure 4 The coated tool 1 of the present disclosure can have a diameter-expanded part 21 connected to the inner wall 17. A step is present at the boundary between the through-hole 15 and the diameter-expanded part 21. Note that in the example shown in Figure 4 In the example shown in

[0048] The thickness T1 of the binder phase-enriched layer 19 in the central part 17a can be 1 μm or more. Also, the thickness T1 can be 20 μm or less. According to this structure, abnormal damage of the coated tool 1 is suppressed. The thickness T1 can also be 3 μm or more. Also, the thickness T1 can also be 10 μm or less.

[0049] The thickness T2 of the binder phase enrichment layer 19 at end 17b can be 0.2 μm or more. Alternatively, the thickness T2 can be 6 μm or less. Based on this structure, abnormal damage to the coated tool 1 is suppressed.

[0050] like Figure 5 As shown, the diameter R1 of the central portion 17a can be larger than the diameter R2 of the end portion 17b. With such a structure, the contact area between the clamping member and the inner wall 17 increases, and the clamping force increases.

[0051] The diameter R1 of the central portion 17a can be 5 μm larger than the diameter R2 of the end portion 17b but less than 30 μm larger. With such a structure, abnormal damage to the coated tool 1 is suppressed.

[0052] The hardness of the binder phase enrichment layer 19 in the central portion 17a can be 10 GPa or higher and 20 GPa or lower. Due to this structure, the binder phase enrichment layer 19 deforms appropriately upon contact with the clamping pin, and the clamping force increases. For the hardness of the binder phase enrichment layer 19 in the central portion 17a, it is preferable to measure the exposed binder phase enrichment layer 19 in the cross-section of the coated tool 1 using a nanoindentation method.

[0053] The binder phase enrichment layer 19 in the central portion 17a may have a metal layer (not shown) on the through-axis side of the through hole 15, where the binder phase content is higher than that of the binder phase enrichment layer 19. This metal layer does not contain a hard layer and is composed only of metal. With such a structure, the metal layer functions as a buffer material between the clamping member (described later) and the binder phase enrichment layer 19, thus suppressing abnormal damage to the coated tool 1. The thickness of the metal layer can be 0.3 μm or more and 2 μm or less.

[0054] <Manufacturing Method of Coated Cutting Tools>

[0055] The following describes the manufacturing method of the coated cutting tool disclosed herein.

[0056] The raw material powder used in the manufacture of the coated cutting tool disclosed herein is the same raw material powder commonly used in the manufacture of cermets.

[0057] The matrix may contain, for example, 40% to 80% by mass of TiCN as hard particles and 6% to 30% by mass of Co as a binder phase. Furthermore, to further enhance properties, the matrix may also contain WC, TaC, NbC, Mo2C, VC, ZrC, etc.

[0058] The raw material having the above composition is shaped into a form having a space that becomes a through hole after firing. Then, for example, firing is carried out at a temperature of 1400°C or higher and 1600°C or lower. The firing atmosphere can be set to a partial pressure N2 atmosphere.

[0059] If the N2 partial pressure is set to 1 kPa or more, the thickness of the binder phase enriched layer after firing becomes thick. In addition, if the average particle diameter d50 of the hard particles used as the raw material is set to 0.7 μm or less, a binder phase enriched layer of a metal layer having a higher content of the binder phase on the side of the through-hole axis (not shown) of the through-hole than the binder phase enriched layer can be obtained.

[0060] Note that, in the molding described above, if the molding pressure is large, deformation at the time of firing can be suppressed. On the other hand, if the molding pressure is reduced at the time of molding, the diameter R1 of the central portion of the inner wall is likely to be larger than the diameter R2 of the end portion. Since the relationship between the molding pressure and the deformation varies depending on the composition or the firing temperature, various combinations can be made to adjust.

[0061] For example, after firing, a rotating brush is inserted into the through-hole from both end portions of the through-hole to polish the inner wall of the through-hole so as to process the thickness T1 of the binder phase enriched layer of the central portion to be thicker than the thickness T2 of the binder phase enriched layer of the end portion. Note that the brush can be inserted from both sides of the through-hole or inserted twice from one side.

[0062] Next, a coating layer is formed on the surface of the substrate by a chemical vapor deposition (CVD) method. First, a titanium carbonitride layer in the first layer is formed on the surface of the substrate. A first mixed gas is prepared by mixing 0.5 vol% or more and 10 vol% or less of titanium tetrachloride gas, 1 vol% or more and 60 vol% or less of nitrogen gas, and 0.1 vol% or more and 3.0 vol% or less of acetonitrile gas in hydrogen gas. While the first mixed gas is introduced into a furnace, the acetonitrile gas is increased by 0.4 vol% each time from the start of the film formation. At this time, the first mixed gas is introduced into the furnace at a gas partial pressure of 6 kPa or more and 12 kPa or less, and the titanium carbonitride layer containing MT-titanium carbonitride is formed in a temperature region of 830°C or more and 870°C or less.

[0063] Next, the second layer 32 is formed. The film formation temperature is set to 950°C or more and 1100°C or less, the gas pressure is set to 5 kPa or more and 20 kPa or less, and the composition of the reaction gas is prepared by mixing 5 vol% or more and 15 vol% or less of aluminum trichloride (AlCl3) gas, 0.5 vol% or more and 2.5 vol% or less of hydrogen chloride (HCl) gas, 0.5 vol% or more and 5.0 vol% or less of carbon dioxide gas, and 0 vol% or more and 1 vol% or less of hydrogen sulfide (H2S) gas in hydrogen. The second mixed gas is introduced into the furnace, and the second layer 32 is formed. Thus, the coating cutter 1 of the present disclosure can be obtained.

[0064] It should be noted that after firing, there may be a binder phase enrichment layer in areas other than the through holes, such as the first, second, or third surface. However, the binder phase enrichment layer can be removed as needed.

[0065] <Cutting Tools>

[0066] The cutting tools of this disclosure will now be described using the accompanying drawings.

[0067] like Figure 7 As shown, the cutting tool 101 of this disclosure, for example, starts from the first end ( Figure 7 The upper end of the middle) faces the second end ( Figure 7 A rod-shaped body extending from the lower end of the middle. For example... Figure 7 As shown, the cutting tool 101 has a tool holder 105 with a tool groove 103 on the first end side (front end side) and the aforementioned coated tool 1 located in the tool groove 103.

[0068] In addition, such as Figure 8 As shown, the clamping member 107 is inserted into the through hole 15 of the coated tool 1 (refer to...). Figure 1 ).exist Figure 8 In the example shown, the clamping member 107 and the adhesive phase enrichment layer 19 located in the central portion 17a (see reference) Figure 2 The contact is direct or indirect. It should be noted that indirect contact between the clamping member 107 and the binder phase enrichment layer 19 refers to the presence of a metal layer or coating between the binder phase enrichment layer 19 and the clamping member 107. The binder phase enrichment layer 19, which is in contact with the clamping member 107, is more prone to deformation than the substrate 3, thus making it less likely to apply locally strong forces to the coated tool 1. Furthermore, the presence of the binder phase enrichment layer 19 results in a large contact area between the clamping member 107 and the binder phase enrichment layer 19, making it less likely for the coated tool 1 to move within the tool groove during cutting. Complementing this effect, the coated tool 1 of this disclosure is less prone to abnormal damage. Because the cutting tool 101 is equipped with the coated tool 1, it can perform stable cutting operations over a long period.

[0069] The cutting groove 103 is a part for mounting the coated cutting tool 1, and has a sitting surface parallel to the lower surface of the tool holder 105 and a limiting side inclined relative to the sitting surface. In addition, the cutting groove 103 has an opening at the first end side of the tool holder 105.

[0070] The coating tool 1 is located in the tool groove 103. At this time, the lower surface of the coating tool 1 can be directly connected to the tool groove 103, or a sheet (not shown) can be sandwiched between the coating tool 1 and the tool groove 103.

[0071] The coated tool 1 is fitted to the shank 105 in a manner in which at least a portion of the portion of the land at which the rake face and the flank face intersect, which is used as the cutting edge 11, protrudes outward from the shank 105. In the present embodiment, the coated tool 1 is fitted to the shank 105 by the clamping member 107. That is, the clamping member 107 is inserted into the through-hole 15 of the coated tool 1, the front end of the clamping member 107 is inserted into a threaded hole (not shown) formed in the pocket 103, and the threaded portions are screwed to each other, thereby fitting the coated tool 1 to the shank 105.

[0072] As the material of the shank 105, steel, cast iron, or the like can be used. A steel having a high toughness can be used among these members.

[0073] In the present embodiment, a cutting tool 101 used in so-called turning processing is exemplified. As the turning processing, for example, internal diameter processing, external diameter processing, grooving processing, face processing, and the like can be exemplified. Note that, as the cutting tool 101, it is not limited to a cutting tool used in turning processing. For example, the coated tool 1 of the above-described embodiment can be used for a cutting tool 101 used in milling processing.

[0074] Embodiment

[0075] Hereinafter, a coated tool of the present disclosure will be described.

[0076] The substrate is produced in the following manner. After an adhesive is added to raw material powder containing 40 mass% of TiCN, 12 mass% of TiN, 20 mass% of WC, 8 mass% of NbC, 20 mass% of Co, and other inevitable carbides, it is adjusted to a desired shape by press forming, thereby producing a shaped body having a tool shape of a through-hole. These raw material powders are raw material powders generally used in the production of cermet. The composition of the substrate of the present disclosure is also not particularly limited. Then, after the adhesive component is removed, firing is performed under a nitrogen atmosphere of 3 kPa at a temperature of 1530°C for 1 hour, thereby obtaining a coated tool having a binder phase-rich layer having a metal layer on the inner wall of the through-hole.

[0077] Then, the inner wall of the through-hole is polished using a brush, thereby producing a coated tool having the structure shown in Table 1. Note that, the portion in which the binder phase-rich layer is not present or the thickness of the binder phase-rich layer is thin is a portion obtained by extending the time of polishing by the brush.

[0078] [Table 1]

[0079] (Table 1)

[0080]

[0081] Note that the first face, the second face, and the third face of any of the coated tools are subjected to the sandblasting treatment, thereby removing the binder phase enriched layer.

[0082] The brush-based polishing is performed by applying a polishing liquid in which 0.1 to 3 μm diamond powder and lubricating oil are mixed to a pig brush, and inserting the pig brush into the through hole while rotating the pig brush. Thereafter, the coating is formed on the substrate based on the aforementioned coating film forming process.

[0083] The thickness of the central portion and the end portion of the binder phase enriched layer, the diameter R1 of the central portion, and the diameter R2 of the end portion are measured using a cross section obtained by cutting the substrate in a plane including the through axis in the thickness direction.

[0084] In addition, when the hardness of the inside of the substrate and the hardness of the binder phase enriched layer are measured using a cross section of the coated tool, the hardness of the binder phase enriched layer is lower than the hardness of the inside of the substrate.

[0085] The obtained coated tool is inserted into the tool groove of the tool shank, and the clamping member is inserted into the through hole of the coated tool, thereby fixing the coated tool with the clamping member. Then, a cutting test is performed under the following conditions.

[0086] <Damage Resistance Test>

[0087] Workpiece: SCM435 with 4 grooves (5 mm wide)

[0088] Cutting speed: 300 m / min

[0089] Feed: 0.3 mm / rev

[0090] Depth of cut: 0.5 mm

[0091] Cutting condition: wet

[0092] Evaluation method: Whether or not the state of chipping or damage after applying 10,000 impacts is judged.

[0093] Sample Nos. 1, 2, and 9, which do not have the structure of the coated tool of the present disclosure, generated abnormal damage. The abnormal damage of the coated tool of the present disclosure was suppressed. In addition, the coated tool was well retained in the tool shank, and the surface roughness of the machined workpiece was also good.

[0094] In addition, the tilt angle of the first layer of the obtained coated cutting tool was measured by a backscattered electron diffraction method. As for the measurement method, as described above. That is, first, the coated cutting tool was cut in a manner that a cross section of the through hole was visualized to expose the coating. Next, the second layer was removed by grinding, polishing, or the like to expose the first layer. Next, after the surface of the first layer was exposed was subjected to polishing processing to smooth the surface, ion milling processing was performed on the measurement site. The cross section of the first layer exposed by this, that is, the polished surface was irradiated with an electron beam, and the tilt angle of the normal line of the {112} plane was measured at intervals of 0.1 pm in a range of about 40 x 25 pm. Then, the measurement tilt angles in a range of 0° or more and 45° or less were divided at intervals of 0.25°. 2

[0095] Note that in the test in Table 1, the total of the degrees in a range of 0° or more and 10° or less of all the samples was 58% of the total degrees in the tilt angle degree distribution graph.

[0096] The coated cutting tool of the present disclosure described above and the cutting tool provided with the same are examples, and can have different structures as long as the gist of the present application is not deviated.

[0097] Explanation of Reference Signs

[0098] 1 ··· Coated cutting tool

[0099] 3 ··· Base

[0100] 5 ··· First surface

[0101] 7 ··· Second surface

[0102] 9 ··· Third surface

[0103] 11 ··· Cutting edge

[0104] 15 ··· Through hole

[0105] 17 ··· Inner wall

[0106] 17a ··· Central portion

[0107] 17b ··· End portion

[0108] 19 ··· Binder phase-rich layer

[0109] 21 ··· Enlarged diameter portion

[0110] T1 ··· Thickness of the binder phase-rich layer of the central portion

[0111] T2 ··· Thickness of the binder phase-rich layer of the end portion

[0112] R1 ··· Diameter of the central portion​

[0113] R2... diameter of end

[0114] 101... cutting tool

[0115] 103... flute

[0116] 105... shank

[0117] 107... clamping member

Claims

1. A coated tool having a substrate of cermet containing hard particles and a binder phase, and a coating layer on the substrate, wherein the coated tool has: a first face; a second face; a cutting edge at at least a part of a ridge line of the first face and the second face; a third face on the opposite side of the first face; and a through hole passing through from the first face to the third face, an inner wall constituting the through hole has, at at least a central portion, a binder phase-rich layer having a higher content of the binder phase than an inside of the substrate, a thickness Tl of the binder phase-rich layer of the central portion is thicker than a thickness T2 of the binder phase-rich layer of an end portion of the inner wall, the coating layer has a first layer containing a titanium compound, and a second layer containing alumina which is located on the first layer in a manner of being continuous, in a cross-section polished surface of the through hole, when an inclination angle of a normal line of a crystal plane {112} plane of a crystal grain of the first layer with respect to a normal line of a surface of the first layer is measured, in a distribution graph of the number of inclination angles in which the measured inclination angle in a range of 0° or more and 45° or less is divided at intervals of 0.25° and the degrees existing in each division are aggregated, a highest peak exists in a range of 0° or more and 10° or less, and a total of the degrees existing in the range of 0° or more and 10° or less accounts for a proportion of 45% or more and 60% or less of the total degrees in the distribution graph of the number of inclination angles.

2. The coated tool according to claim 1, wherein the thickness Tl is 1 μm or more and 20 μm or less.

3. The coated tool according to claim 1 or 2, wherein the thickness T2 is 0.2 μm or more and 6 μm or less.

4. The coated tool according to claim 1 or 2, wherein a diameter Rl of the central portion is larger than a diameter R2 of the end portion.

5. The coated tool according to claim 4, wherein the diameter Rl is larger than the diameter R2 by 5 μm or more and 30 μm or less.

6. The coated tool according to claim 1 or 2, wherein a hardness of the binder phase-rich layer of the central portion is 10 GPa or more and 20 GPa or less.

7. The coated tool according to claim 1 or 2, wherein the binder phase-rich layer of the central portion has a metal layer having a content of the binder phase more than the binder phase-rich layer on a through hole axis side of the through hole.

8. A cutting tool, wherein the cutting tool has: a shank having a length from a first end to a second end, and having a pocket on the first end side; the coated tool according to any one of claims 1 to 7, which is located in the pocket; and a clamping member inserted into the through hole of the coated tool. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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