Cutting tool

Abstract

The cutting tool of the present invention is a cutting tool having a substrate and a coating disposed on the substrate, wherein the coating comprises a first layer made of MoC 1‑x Layer or TaC 1‑y The MoC layer structure 1‑x Layers composed of MoC 1‑x The compound shown is composed of TaC 1‑y Layer by TaC 1‑y The compound shown is composed of the MoC 1‑x The compound shown has a hexagonal crystal structure, where x is greater than or equal to 0.40 and less than or equal to 0.60, and the TaC... 1‑y The compound shown contains more than 95% by mass of a hexagonal crystal structure, wherein y is 0.40 or more and 0.60 or less.

Description

Technical Field

[0001] This disclosure relates to cutting tools. This application claims priority to international applications filed May 20, 2021, namely PCT / JP2021 / 019172 and PCT / JP2021 / 019173. The entire contents of those international applications are incorporated herein by reference. Background Technology

[0002] Various studies have been conducted with the aim of extending the lifespan of cutting tools. For example, Patent Document 1 discloses a method of configuring a substrate with WC... 1-x Cutting tools for coating layers.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2019 / 181742 Summary of the Invention

[0006] The cutting tool disclosed herein is a cutting tool having a substrate and a coating disposed on the substrate, wherein,

[0007] The coating comprises a first layer.

[0008] The first layer is composed of MoC 1-x Layer or TaC 1-y The MoC layer structure 1-x Layers composed of MoC 1-x The compound shown is composed of TaC 1-y Layer by TaC 1-y The compound shown is composed of,

[0009] The MoC 1-x The compound shown is composed of a hexagonal crystal structure.

[0010] The x value is greater than 0.40 and less than 0.60.

[0011] The TaC 1-y The compound shown contains more than 95% by mass of a hexagonal crystal structure.

[0012] The value of y is greater than 0.40 and less than 0.60. Attached Figure Description

[0013] Figure 1 This is a perspective view illustrating one method of using a cutting tool.

[0014] Figure 2This is a schematic cross-sectional view of the cutting tool in one embodiment of this invention.

[0015] Figure 3 This is a schematic cross-sectional view of the cutting tool in another embodiment of this invention.

[0016] Figure 4 This is a schematic cross-sectional view of the cutting tool in another embodiment of this invention. Detailed Implementation

[0017] [The problem this disclosure aims to solve]

[0018] In recent years, the demand for high-speed, high-efficiency machining with high load capacity has been increasing, seeking cutting tools that can achieve high speed and high efficiency while also having a long tool life.

[0019] [The Effects of This Disclosure]

[0020] According to this disclosure, a cutting tool with a long tool life can be provided even in high-speed, high-efficiency machining.

[0021] [Description of embodiments of this disclosure]

[0022] First, embodiments of this disclosure will be described.

[0023] (1) The cutting tool disclosed herein is a cutting tool having a substrate and a coating disposed on the substrate, wherein,

[0024] The coating comprises a first layer.

[0025] The first layer is composed of MoC 1-x Layer or TaC 1-y The MoC layer structure 1-x Layers composed of MoC 1-x The compound shown is composed of TaC 1-y Layer by TaC 1-y The compound shown is composed of,

[0026] The MoC 1-x The compound shown is composed of a hexagonal crystal structure.

[0027] The x value is greater than 0.40 and less than 0.60.

[0028] The TaC 1-y The compound shown contains more than 95% by mass of a hexagonal crystal structure.

[0029] The value of y is greater than 0.40 and less than 0.60.

[0030] According to this disclosure, a cutting tool with a long tool life can be provided even in high-speed, high-efficiency machining.

[0031] (2) Preferably, the first layer does not contain free carbon. Accordingly, the chipping resistance and wear resistance of the cutting tool are improved.

[0032] (3) Preferably, the film hardness of the first layer is 2700 mgf / μm. 2 Above and 4200 mgf / μm 2 Therefore, the chipping resistance and wear resistance of cutting tools are improved.

[0033] (4) Preferably, the first layer is in contact with the substrate. Accordingly, the cutting tool can have excellent resistance to chipping and wear.

[0034] (5) Preferably, the coating further comprises a rigid coating layer disposed between the substrate and the first layer.

[0035] The rigid coating layer comprises a first unit layer.

[0036] The composition of the first unit layer is different from that of the first layer.

[0037] The first unit layer is composed of at least one element selected from the group consisting of elements of Group 4, Group 5, Group 6, aluminum, and silicon in the periodic table, or is composed of a compound consisting of at least one element selected from the group consisting of elements of Group 4, Group 5, Group 6, aluminum, and silicon in the periodic table and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron.

[0038] As a result, the cutting tool's resistance to chipping and wear is improved.

[0039] (6) Preferably, the rigid coating layer is composed of the first unit layer.

[0040] The thickness of the first unit layer is greater than 0.1 μm and less than 15 μm.

[0041] As a result, the cutting tool's resistance to chipping and wear is improved.

[0042] (7) Preferably, the rigid coating layer further comprises a second unit layer.

[0043] The composition of the second unit layer differs from that of the first layer and the composition of the first unit layer.

[0044] The second unit layer is composed of at least one element selected from the group consisting of elements from Group 4, Group 5, Group 6 of the periodic table, aluminum, and silicon, or a compound composed of at least one element selected from the group consisting of elements from Group 4, Group 5, Group 6 of the periodic table, aluminum, and silicon, and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron.

[0045] The first unit layer and the second unit layer form a multi-layer structure with one or more layers stacked alternately.

[0046] As a result, the cutting tool's resistance to chipping and wear is improved.

[0047] (8) Preferably, the thickness of the first unit layer is 1 nm or more and 100 nm or less.

[0048] The thickness of the second unit layer is greater than 1 nm and less than 100 nm. Accordingly, the chipping resistance and wear resistance of the cutting tool are improved.

[0049] (9) Preferably, the thickness of the first layer is 0.1 μm or more and 10 μm or less.

[0050] The thickness of the hard coating layer is 0.1 μm or more and 10 μm or less. This improves the chipping resistance and wear resistance of the cutting tool.

[0051] (10) Preferably, the thickness of the coating is 0.2 μm or more and 20 μm or less. Accordingly, the chipping resistance and wear resistance of the cutting tool are improved.

[0052] (11) Preferably, the substrate comprises at least one selected from the group consisting of cemented carbide, cermet, high-speed steel, ceramic, cubic boron nitride sintered body, and diamond sintered body. Accordingly, the cutting tool can also exhibit excellent hardness and strength at high temperatures.

[0053] [Details of the embodiments disclosed herein]

[0054] Hereinafter, specific examples of the cutting tools of this disclosure will be described with reference to the accompanying drawings. In the drawings of this disclosure, the same reference numerals denote the same or equivalent parts. In addition, for the purpose of clarity and simplification of the drawings, appropriate changes have been made to dimensional relationships such as length, width, thickness, and depth, and these do not represent actual dimensional relationships.

[0055] In this specification, the expression "A~B" refers to the upper and lower limits of the range (i.e., above A and below B). If there is no unit in A but only in B, the unit of A is the same as the unit of B.

[0056] In this specification, when compounds are represented by chemical formulas, all known atomic ratios are included unless otherwise specified, and the specification should not be limited to stoichiometric ranges. For example, when referred to as "TiAlN", the ratio of the number of atoms constituting TiAlN includes all known atomic ratios.

[0057] [Implementation Method 1: Cutting Tool]

[0058] The cutting tool disclosed herein (hereinafter also referred to as Embodiment 1 or this embodiment) is a cutting tool having a substrate and a coating disposed on the substrate.

[0059] The coating comprises a first layer.

[0060] The first layer is composed of MoC 1-x Layer or TaC 1-y The MoC layer structure 1-x Layers composed of MoC 1-x The compound shown is composed of TaC 1-y Layer by TaC 1-y The compound shown is composed of,

[0061] The MoC 1-x The compound shown is composed of a hexagonal crystal structure.

[0062] The x value is greater than 0.40 and less than 0.60.

[0063] The TaC 1-y The compound shown contains more than 95% by mass of a hexagonal crystal structure.

[0064] The value of y is greater than 0.40 and less than 0.60.

[0065] The cutting tool of this embodiment (hereinafter, sometimes simply referred to as "cutting tool") includes a substrate and a coating disposed on the substrate. The cutting tool may be, for example, a drill bit, an end mill, an indexable cutting insert for a drill bit, an indexable cutting insert for an end mill, an indexable cutting insert for milling, an indexable cutting insert for turning, a metal saw, a gear cutting tool, a reamer, a tap, etc.

[0066] Figure 1This is a perspective view illustrating one type of cutting tool. The cutting tool with the above-described shape is used, for example, as an indexable cutting insert. The cutting tool 10 has a rake face 1, a flank face 2, and a cutting edge 3 where the rake face 1 and the flank face 2 intersect. That is, the rake face 1 and the flank face 2 are surfaces that clamp the cutting edge 3. The cutting edge 3 constitutes the cutting tip of the cutting tool 10. The shape of the cutting tool 10 can also be understood as the shape of the base material of the cutting tool. That is, the base material has a rake face, a flank face, and a cutting edge connecting the rake face and the flank face.

[0067] <Substrate>

[0068] Regarding the substrate of this embodiment, any substrate that is known in the prior art as such a substrate can be used. For example, the substrate is preferably selected from at least one of the following groups: cemented carbide (e.g., tungsten carbide (WC) based cemented carbide, WC-Co type cemented carbide, WC-TaC-Co type cemented carbide, cemented carbide with added carbonitrides such as Cr, Ti, Ta, Nb, etc.), cermet (with TiC, TiN, TiCN, etc. as the main components), high-speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, alumina, etc.), cubic boron nitride sintered body (cBN sintered body), and diamond sintered body. More preferably, it is selected from at least one of the following groups: cemented carbide, cermet, and cBN sintered body.

[0069] It should be noted that when using cemented carbide as the substrate, the cemented carbide exhibits the effects of this embodiment even if the microstructure contains free carbon or an abnormal phase called the η phase. It should also be noted that the substrate used in this embodiment can be a substrate whose surface has been modified. For example, in the case of cemented carbide, a de-β layer can be formed on its surface, or in the case of cermet, a surface-cured layer can be formed; even if the surface is modified in this way, the effects of this embodiment are still exhibited.

[0070] When the cutting tool is an indexable cutting insert (such as an indexable cutting insert for milling), the base material includes cases with and without a chip breaker. The shape of the edge portion of the tool tip includes any of the following: a sharp edge (the edge where the rake face and flank face intersect), honing (a shape formed by applying an arc to a sharp edge), a negative cutting edge (a shape that is chamfered), or a shape formed by combining honing and a negative cutting edge.

[0071] <Lamination>

[0072] The "coating" involved in this embodiment is a coating that improves various properties of the cutting tool, such as chip resistance and wear resistance, by covering at least a portion of the surface of the substrate. Here, "at least a portion of the surface of the substrate" includes the part that comes into contact with the material being cut during cutting. This part in contact with the material being cut can be, for example, a region on the surface of the substrate within 2 mm of the cutting edge. It should be noted that even if a portion of the substrate is not covered by the coating, or if the composition of the coating is partially different, it will not deviate from the scope of this embodiment.

[0073] like Figure 2 As shown, the coating 4 can be composed of a first layer 12. (As...) Figure 3 as well as Figure 4 As shown, the coating 4 can include a first layer 12 and a rigid coating layer 13 disposed between the first layer 12 and the substrate 11. The coating 4 can also include other layers in addition to the first layer 12. Examples of other layers include, for example, a base layer (not shown) disposed between the rigid coating layer and the substrate, an intermediate layer (not shown) disposed between the first layer and the rigid coating layer, and a surface layer (not shown) disposed on top of the first layer.

[0074] The thickness of the aforementioned coating is preferably 0.1 μm or more and 20 μm or less, more preferably 0.1 μm or more and 10 μm or less, more preferably 0.2 μm or more and 20 μm or less, more preferably 0.2 μm or more and 10 μm or less, more preferably 0.3 μm or more and 10 μm or less, further preferably 0.5 μm or more and 10 μm or less, more preferably 1 μm or more and 6 μm or less, and particularly preferably 1.5 μm or more and 4 μm or less. When the thickness is 0.1 μm or more, the wear resistance of the cutting tool is improved. When the thickness is 0.2 μm or more, the wear resistance of the cutting tool is further improved. When the thickness is 20 μm or less, it is easier to suppress peeling or damage of the coating when large stress is applied between the coating and the substrate during intermittent processing. Here, the thickness of the coating refers to the thickness of the coating constituting MoC. 1-x Layer, TaC 1-y The thickness of the coating is the sum of the individual thicknesses of the layers, including the hard coating layer and the substrate layer. The thickness of these coatings can be determined by measuring any three points in a cross-sectional sample parallel to the normal direction of the substrate surface using a transmission electron microscope (TEM), and taking the average of the thicknesses at the three points. The MoC thickness will be measured later. 1-x Layer, TaC 1-y The thicknesses of the layers, the hard coating layers (first unit layer, second unit layer), and the base layer are also similar. For example, the spherical aberration correction device JEM-2100F (trademark) manufactured by Nippon Electron Co., Ltd. can be cited as a transmission electron microscope.

[0075] It should be noted that when the same sample is tested, even if the selected location of the test area is changed and multiple tests are performed, there is almost no deviation in the test results. Even if the test area is set arbitrarily, it will not result in arbitrary test results.

[0076] <First Layer>

[0077] In this embodiment, the coating comprises a first layer, which is made of MoC 1-x Layer or TaC 1-y The MoC layer structure 1-x Layers composed of MoC 1-x The compound shown is composed of TaC 1-y Layer by TaC 1-y The compound shown is composed of...

[0078] <MoC 1-x Layer >

[0079] In this embodiment, MoC 1-x Layers composed of MoC 1-x The compound shown is composed of "MoC". 1-x The compound shown (hereinafter, sometimes referred to as "MoC") 1-x ") refers to molybdenum carbide in which the elemental ratio of molybdenum (Mo) is set to 1, and the elemental ratio of carbon (C) is 1-x. The MoC 1-x The layer may contain unavoidable impurities to a extent that does not impair the effectiveness of the cutting tool involved in this embodiment. Examples of such unavoidable impurities include hydrogen, oxygen, nitrogen, and argon. Preferably, relative to MoC... 1-x The total mass of the layer contains unavoidable impurities at a rate of 0% to 0.2% by mass or less. Similarly, the descriptions of "hard coating" and "other layers" described later can also include unavoidable impurities to the extent that they do not impair the performance of the cutting tool involved in this embodiment.

[0080] The aforementioned x is 0.40 or more and 0.60 or less, preferably 0.45 or more and 0.55 or less, and more preferably 0.50 or more and 0.55 or less. When the aforementioned x is less than 0.40, in MoC 1-x Free carbon precipitates at the grain boundaries, leading to a decrease in strength. Furthermore, when x is greater than 0.60, the strength of the grain boundary decreases. Therefore, when x is outside the range of 0.40 to 0.60, crack propagation cannot be suppressed, resulting in a decrease in toughness. The inventors of this invention speculate that this trend is caused by an inappropriate balance between the homogeneity of the crystal and strain.

[0081] The above x can be obtained by the following method: (The result is in MoC...) 1-x A cross-sectional sample parallel to the normal direction of the substrate surface in the layer was analyzed for grains appearing in the cross-sectional sample using a scanning electron microscope (SEM) or an energy dispersive X-ray spectroscopy (EDX) device attached to a TEM. Specifically, the MoC of the above-mentioned cross-sectional sample was measured. 1-x The value of x is calculated at any three points in the layer, and the average of the calculated values ​​at the three points is set as the MoC of the above profile sample. 1-x x in the layer. Here, "any three points" refers to selecting three MoC locations. 1-x Any 30nm × 30nm region within the layer. Examples of EDX devices include the silicon drift detector JED-2200 (trademark) manufactured by Nippon Electronics Co., Ltd. Measurement conditions are as described below.

[0082] Determination conditions of EDX method

[0083] Accelerating voltage: 200kV

[0084] Probe current: 0.29nA

[0085] Probe size: 0.2nm

[0086] It should be noted that when the same sample is tested, even if the selected location of the test area is changed and multiple tests are performed, there is almost no deviation in the test results. Even if the test area is set arbitrarily, it will not result in arbitrary test results.

[0087] The above MoC 1-x The compound shown has a hexagonal crystal structure. Here, the aforementioned MoC... 1-x The compound shown is composed of a hexagonal crystal structure, referring to the aforementioned MoC. 1-x The percentage of hexagonal crystal structure in the compound shown is 100% by mass, and it does not contain other crystal structures. The above MoC 1-x The compound shown is composed of a hexagonal crystal structure, for example, through the above-mentioned MoC 1-x X-ray diffraction (XRD) measurements were performed at any three points within the layer, and the results were analyzed to confirm the findings. In the aforementioned MoC... 1-xWhen the compound shown is composed of a hexagonal crystal structure, in XRD measurements, peaks originating from the hexagonal crystal planes, such as the (100), (002), (101), (102), (110), (103), (112), and (201) planes, can be observed at all measurement points at the three points. Peaks originating from crystal planes other than hexagonal crystals cannot be observed. Examples of devices used for the above X-ray diffraction measurements include "SmartLab" (trade name) manufactured by Riko Co., Ltd., and "X'pert" (trade name) manufactured by Panalytical. The measurement conditions are described below.

[0088] XRD determination conditions

[0089] Scan axis: 2θ-θ

[0090] X-ray source: Cu-Kα rays

[0091] Detector: Zero-dimensional detector (scintillation counter)

[0092] Tube voltage: 45kV

[0093] Tube current: 40mA

[0094] Incident optical systems: the use of mirrors

[0095] Receiving optical system: Utilization of a beam-splitting crystal (PW3098 / 27)

[0096] Light amplitude: 0.03°

[0097] Total time: 2 seconds

[0098] Scan range (2θ): 10°~120°

[0099] It should be noted that when the same sample is tested, even if the selected location of the test area is changed and multiple tests are performed, there is almost no deviation in the test results. Even if the test area is set arbitrarily, it will not result in arbitrary test results.

[0100] <TaC 1-y Layer >

[0101] In this embodiment, TaC 1-y Layer by TaC 1-y The compound shown is composed of "TaC". 1-y The compound shown (hereinafter, sometimes referred to as "TaC") 1-y ") refers to tantalum carbide in which the elemental ratio of tantalum (Ta) is set to 1, and the elemental ratio of carbon (C) is 1-y. The TaC 1-yThe layer may contain unavoidable impurities to a extent that does not impair the effectiveness of the cutting tool involved in this embodiment. Examples of such unavoidable impurities include hydrogen, oxygen, nitrogen, and argon. Preferably, relative to TaC... 1-y The total mass of the layer contains an unavoidable impurity content of more than 0% by mass and less than 0.2% by mass.

[0102] The aforementioned y is 0.40 or higher and 0.60 or lower, preferably 0.45 or higher and 0.55 or lower, and more preferably 0.50 or higher and 0.55 or lower. When the aforementioned y is less than 0.40, in TaC... 1-y Free carbon precipitates at the grain boundaries, leading to a decrease in strength. Furthermore, when y is greater than 0.60, the strength of the grain boundaries decreases. Therefore, when y is outside the aforementioned range, crack propagation cannot be suppressed, resulting in a decrease in toughness. The inventors of this invention speculate that this tendency is caused by an inappropriate balance between the homogeneity of the crystal and strain.

[0103] The above y and the above MoC 1-x The x-value in the layer was determined similarly using SEM or EDX attached to TEM. The specific measurement methods and conditions were set as described above for MoC. 1-x The method and conditions for measuring x in the layer are the same.

[0104] It should be noted that when the same sample is tested, even if the selected location of the test area is changed and multiple tests are performed, there is almost no deviation in the test results. Even if the test area is set arbitrarily, it will not result in arbitrary test results.

[0105] The above TaC 1-y The compound shown contains more than 95% by mass of a hexagonal crystal structure. TaC 1-y The content of the hexagonal crystal structure in the compound shown is preferably 96% by mass or more, more preferably 98% by mass or more, and even more preferably 100% by mass. The above TaC 1-y The compound shown contains more than 95% by mass of a hexagonal crystal structure, which was confirmed by the following methods. In the analysis of TaC... 1-y XRD measurements are performed at any point in the layer to identify n peaks originating from hexagonal crystal planes (representatively (100), (002), (101), (110), (102), (103), (112), (201), etc.). For each peak, the peak intensity li (i = 1, 2, ..., n) and half-width Wi (i = 1, 2, ..., n) are calculated, and the peak area ΣSi (li × Wi) (i = 1, 2, ..., n) is calculated. This peak area ΣSi is defined as TaC. 1-yThe amount (mass%) of the hexagonal crystal structure in the compound shown.

[0106] At the same measurement points as above, when peaks originating from cubic crystal planes (representatively (100), (111), (200), (220), (311), etc.) are observed, the peak area ΣS'i(l'i×W'i) (i=1, 2, …, n) is calculated in the same manner as above. This peak area ΣS'i is defined as TaC. 1-y The amount of cubic crystal structure (mass%) in the compound shown.

[0107] Calculate the percentage of the hexagonal crystal structure quantity ΣSi relative to the sum of the hexagonal crystal structure quantity ΣSi and the cubic crystal structure quantity ΣS'i (ΣSi / (ΣSi+ΣS'i)×100). For TaC 1-y The above XRD measurements were performed at any three points in the layer, and the average value of (ΣSi / (ΣSi+ΣS'i)×100) at the three points was calculated. This average value was defined as TaC. 1-y The percentage (mass%) of hexagonal crystal structure in the compound shown.

[0108] It should be noted that in the above TaC 1-y When the compound shown consists solely of a hexagonal crystal structure, in XRD measurements, peaks originating from hexagonal crystal planes such as (100), (002), (101), (110), (102), (103), (112), and (201) can be observed at all measurement points at three points. Peaks originating from crystal planes other than hexagonal crystals cannot be observed. The apparatus and conditions for X-ray diffraction measurements described above are the same as those for the MoC described above. 1-x The method for confirming the crystal structure of the compounds shown is the same.

[0109] It should be noted that when the same sample is tested, even if the selected location of the test area is changed and multiple tests are performed, there is almost no deviation in the test results. Even if the test area is set arbitrarily, it will not result in arbitrary test results.

[0110] Figure 2 This is a schematic cross-sectional view of the cutting tool in one embodiment of this invention. Figure 2 As shown, the first layer 12 is preferably in contact with the substrate 11. In other words, the first layer 12 is preferably disposed directly above the substrate 11.

[0111] In the cemented carbide of this embodiment, the first layer preferably does not contain free carbon. Here, "the first layer does not contain free carbon" has two meanings: the first layer contains absolutely no free carbon; and the amount of free carbon in the first layer is less than the detection limit. "Free carbon" refers to carbon that exists as a monomer rather than a constituent element of the first layer. Examples of free carbon include graphite, coal, and other monomers containing carbon-carbon double bonds. The presence or absence of free carbon can be confirmed by using X-ray photoelectron spectroscopy (XPS) to examine the presence or absence of carbon-carbon double bonds at any three points on the surface of the first layer (the presence or absence of the C=C peak in XPS C1s). If carbon-carbon double bonds are present at one or more of the aforementioned three points, the first layer is determined to contain free carbon. If carbon-carbon double bonds are not present at any of the aforementioned three points, the first layer is determined to not contain free carbon. Here, when the first layer is disposed on the outermost surface of the coating, the presence or absence of free carbon is determined by using Ar... + After removing the natural oxide layer by sputtering or other methods, the presence or absence of free carbon is determined as described above. In cases where the first layer is not the outermost layer, Ar... + After the first layer is exposed by sputtering or other methods, the presence or absence of free carbon is determined. For example, the Versa Probe Ⅲ (trade name) manufactured by ULVAC-PHI Co., Ltd. can be used as an apparatus for the XPS method. The measurement conditions are described below.

[0112] XPS determination conditions

[0113] X-ray source used: mono-AlKα line (hν = 1486.6 eV)

[0114] Detection depth: 1nm~10nm

[0115] X-ray beam diameter: approximately

[0116] Neutralization gun: uses a twin-barrel type

[0117] Ar + Accelerating voltage 4kV

[0118] grating size: 1×1mm

[0119] Sputtering velocity (Ar) + SiO2 sputtering conversion value: 28.3 nm / min

[0120] It should be noted that when the same sample is tested, even if the selected location of the test area is changed and multiple tests are performed, there is almost no deviation in the test results. Even if the test area is set arbitrarily, it will not result in arbitrary test results.

[0121] The preferred hardness of the first layer of film is 2700 mgf / μm. 2 Above and 4200 mgf / μm 2 The following is more preferably 2700 mgf / μm 2 Above and 4100 mgf / μm 2 The following is more preferably 2800 mgf / μm 2 Above and 4000 mgf / μm 2 The film hardness described above was measured using a nanoindenter. Specifically, the film hardness was first determined by measuring the hardness at ten arbitrary points on the surface of the first layer. Then, the average hardness of the ten points was taken as the film hardness in the first layer of the cross-sectional sample. In cases where the first layer was not the outermost surface, it was exposed by mechanical grinding or the like before measurement using a nanoindenter. For example, the ENT1100 (trade name) manufactured by ELIONIX Co., Ltd. can be used as a nanoindenter. The measurement conditions are described below.

[0122] Measurement conditions of nanoindentation instrument

[0123] Head press: Berkovic head press

[0124] Load: 1gf

[0125] Loading time: 10 seconds

[0126] Hold time: 2 seconds

[0127] Unloading time: 10 seconds

[0128] It should be noted that when the same sample is tested, even if the selected location of the test area is changed and multiple tests are performed, there is almost no deviation in the test results. Even if the test area is set arbitrarily, it will not result in arbitrary test results.

[0129] The thickness of the first layer is preferably 0.1 μm or more and 10.0 μm or less, more preferably 0.1 μm or more and 7 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

[0130] <Rigid Coating>

[0131] The aforementioned coating preferably further includes a rigid coating layer disposed between the substrate and the first layer. This rigid coating layer preferably includes a first unit layer. The composition of the first unit layer is preferably different from the composition of the first layer. Here, "disposed between the substrate and the first layer" means that the rigid coating layer only needs to be disposed between the substrate and the first layer; it is not necessary for the rigid coating layer to contact the substrate or the first layer. Alternatively, other layers may be disposed between the substrate and the rigid coating layer, or between the rigid coating layer and the first layer.

[0132] <First Unit Layer>

[0133] The first unit layer is preferably composed of at least one element selected from the group consisting of elements from Group 4, Group 5, Group 6, aluminum, and silicon of the periodic table, or a compound composed of at least one element selected from the group consisting of elements from Group 4, Group 5, Group 6, aluminum, and silicon of the periodic table and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron. More preferably, the first unit layer is composed of at least one element selected from the group consisting of chromium, aluminum, titanium, and silicon, or a compound composed of at least one element selected from the group consisting of chromium, aluminum, titanium, and silicon and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron. Examples of Group 4 elements include titanium (Ti), zirconium (Zr), and hafnium (Hf). Examples of Group 5 elements include vanadium (V), niobium (Nb), and tantalum (Ta). Examples of Group 6 elements include chromium (Cr), molybdenum (Mo), and tungsten (W).

[0134] Compounds included in the first unit layer include, for example, TiAlN, TiAlSiCN, TiAlSiON, TiAlBCN, TiAlSiN, TiCrSiN, TiAlCrSiN, AlCrN, AlCrO, AlCrSiN, TiZrN, TiAlMoN, TiAlNbN, TiSiN, AlCrTaN, AlTiVN, TiB2, TiCrHfN, CrSiWN, TiAlCN, TiSiCN, AlZrON, AlCrCN, AlHfN, CrSiBON, CrAlBN, TiAlWN, AlCrMoCN, TiAlBN, TiAlCrSiBCNO, ZrN, ZrB2, ZrCN, CrSiBN, AlCrBN, AlCrBON, etc.

[0135] In the case where the rigid coating layer consists only of the aforementioned first unit layer (for example, in...) Figure 3In the case of the above-mentioned first unit layer (i.e., the above-mentioned hard coating layer), the thickness is preferably 0.1 μm or more and 15 μm or less, more preferably 0.1 μm or more and 10 μm or less, and even more preferably 0.5 μm or more and 7 μm or less.

[0136] <Second Unit Layer>

[0137] The rigid coating layer preferably further comprises a second unit layer. The composition of the second unit layer is preferably different from that of the first layer and the first unit layer. The second unit layer is preferably composed of at least one element selected from the group consisting of Group 4, Group 5, Group 6 elements, aluminum, and silicon, or a compound composed of at least one element selected from the group consisting of Group 4, Group 5, Group 6 elements, aluminum, and silicon, and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron. The second unit layer is preferably composed of at least one element selected from the group consisting of chromium, aluminum, titanium, and silicon, or a compound composed of at least one element selected from the group consisting of chromium, aluminum, titanium, and silicon, and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron. Specific examples of Group 4, Group 5, and Group 6 elements of the periodic table can be listed above.

[0138] Compounds included in the second unit layer, such as the compounds mentioned above that can be exemplified as compounds included in the first unit layer.

[0139] The first unit layer and the second unit layer are preferably formed as a multi-layer structure in which one or more layers are alternately stacked. That is, as shown in the figure below. Figure 4 As shown, the rigid coating layer 13 preferably comprises a multilayer structure consisting of a first unit layer 131 and a second unit layer 132. Alternatively, the multilayer structure can be stacked starting from either the first unit layer or the second unit layer. That is, the interface on the first layer side of the multilayer structure can be composed of either the first unit layer or the second unit layer. Alternatively, the interface opposite to the first layer side of the multilayer structure can be composed of either the first unit layer or the second unit layer.

[0140] When the hard coating layer comprises a multi-layer structure, the thickness of the hard coating layer is preferably 0.1 μm or more and 10 μm or less, more preferably 0.5 μm or more and 7 μm or less. When the hard coating layer comprises a multi-layer structure, the thickness of the first layer is 0.1 μm or more and 10 μm or less, and the thickness of the hard coating layer is preferably 0.1 μm or more and 10 μm or less. Accordingly, the chipping resistance and wear resistance of the cutting tool are improved.

[0141] When the rigid coating layer comprises a multilayer structure, the thickness of the first unit layer is preferably 1 nm or more and 100 nm or less, more preferably 1 nm or more and 50 nm or less, and more preferably 2 nm or more and 25 nm or less. Further, the thickness of the second unit layer is preferably 1 nm or more and 100 nm or less, more preferably 1 nm or more and 60 nm or less, and more preferably 2 nm or more and 25 nm or less. In one embodiment of this invention, when the rigid coating layer comprises a multilayer structure, it is preferable that the thickness of the first unit layer is 1 nm or more and 100 nm or less, and the thickness of the second unit layer is 1 nm or more and 100 nm or less. Here, "thickness of the first unit layer" refers to the thickness of each layer of the first unit layer. "Thickness of the second unit layer" refers to the thickness of each layer of the second unit layer.

[0142] When the total thickness of the rigid coating layer is within the above-mentioned range, the number of layers in the multilayer structure can include a first unit layer and a second unit layer, each of which is stacked separately, and it is preferably configured as a multilayer structure in which each of the two layers has 20 to 2500 layers.

[0143] <Other Layers>

[0144] Without impairing the effects of this embodiment, the coating may include other layers in addition to the first layer and the rigid coating layer. These other layers may have different or the same composition as the first layer and the rigid coating layer. The position of these other layers in the coating is not particularly limited. Examples of other layers include a base layer disposed between the substrate and the first layer, an intermediate layer disposed between the first layer and the rigid coating layer, and a surface layer disposed above the first layer. Examples of other layers include TiN layers, TiWCN layers, TiCN layers, ZrB2 layers, TiSiN layers, and AlCrN layers.

[0145] The thickness of other layers is not particularly limited without impairing the effects of this embodiment. For example, thicknesses of 0.002 μm or more and 10 μm or less can be listed. The thickness of other layers can be set to 0.003 μm or more and 1 μm or less, 0.003 μm or more and 0.01 μm or less, 0.5 μm or more and 10 μm or less, or 0.5 μm or more and 5 μm or less.

[0146] [Implementation Method 2: Method for Manufacturing a Cutting Tool]

[0147] The method for manufacturing a cutting tool according to this embodiment includes a substrate preparation step and a first layer coating step. Each step will be described below.

[0148] <Substrate Preparation Process>

[0149] In the substrate preparation process, the aforementioned substrate is prepared. As described above, any known substrate can be used. For example, if the substrate is made of cemented carbide, a raw material powder consisting of a predetermined blending composition (mass %) is first uniformly mixed using a commercially available grinder. Next, the mixed powder is press-formed into a predetermined shape (e.g., SEET13T3AGSN, CNMG120408N-EG, etc.). Then, the press-formed mixed powder is sintered in a predetermined sintering furnace at 1300–1500°C or below for 1–2 hours, thereby obtaining the aforementioned substrate made of cemented carbide. Alternatively, commercially available products can be used directly as the substrate. For example, Sumitomo Electric Industries Hartmetalle Co., Ltd.'s EH520 (trademark) is an example of a commercially available product.

[0150] <First layer coating process>

[0151] In the first coating process, a cutting tool is obtained by coating at least a portion of the surface of the aforementioned substrate with a first layer. Here, "at least a portion of the surface of the substrate" includes the portion that comes into contact with the material being cut during the cutting process. This portion that comes into contact with the material being cut can, for example, be a region on the surface of the substrate within 2 mm of the tool tip edge.

[0152] There are no particular limitations on the method of covering at least a portion of the aforementioned substrate with a first layer. For example, methods of forming the first layer by physical vapor deposition (PVD) can be cited.

[0153] The aforementioned physical vapor deposition method can be used without particularly limiting existing known physical vapor deposition methods. Examples of such physical vapor deposition methods include sputtering, ion plating, arc ion plating, and electro-ion beam evaporation. In particular, when using cathodic arc ion plating and sputtering, which have high ion rates of the raw material elements, the substrate surface can be subjected to metal bombardment and / or gas ion bombardment treatment before forming the coating, thus significantly improving the sealing performance between the coating and the substrate, and is therefore preferred.

[0154] MoC 1-x The Formation of Layers

[0155] Mo has a high melting point and is difficult to melt. Therefore, stable discharge cannot be maintained in physical vapor deposition, making it impossible to form a MoC layer with good film quality composed of hexagonal MoC. Through in-depth research, the inventors of this invention discovered a method to stably fabricate hexagonal MoC layers. 1-x The MoC structure with good film quality 1-xThe method involves layering. Below, as an example of this method, we will examine MoC formed by arc ion plating with a hexagonal crystal structure. 1-x The case of layer (0.40≤x≤0.60) will be explained.

[0156] First, a MoC target is placed on an arc evaporation source within the apparatus, and the substrate temperature is set to 450–600°C, followed by vacuum evaporation. Next, one or both of argon and krypton are introduced, and the pressure within the apparatus is set to 1.0–3.0 Pa. Then, a negative bias of 200–1000 V is applied to the substrate via a DC power supply, and the substrate surface is cleaned for 40 minutes. Afterward, by supplying an arc current of 80–200 A to the cathode electrode, metal ions are generated from the arc evaporation source, thereby forming hexagonal MoC. 1-x Layer (0.40≤x≤0.60). At this point, in MoC... 1-x In the initial stage of layer formation (within the range of film thickness 0.1 μm or less), the substrate temperature is set to 400–450°C and the substrate bias voltage is set to -50V. As formation progresses, the temperature is gradually increased to 450–550°C and the substrate bias voltage is increased to -60–-75V. For example, an AIP (trade name) manufactured by Kobe Steel Corporation can be cited as an apparatus for arc ion plating.

[0157] TaC 1-y The Formation of Layers

[0158] Ta has a high melting point and is difficult to melt. Therefore, stable discharge cannot be maintained in physical vapor deposition, failing to form a TaC layer containing a cubic crystal structure and possessing good film quality. Through in-depth research, the inventors of this invention discovered a method to stably fabricate TaC containing a hexagonal crystal structure. 1-y TaC with good membrane properties 1-y Layering method. Below, as an example of this method, an example is taken of TaC crystals with a hexagonal crystal structure containing more than 95% by mass formed by arc ion plating. 1-y The case of layer (0.40≤y≤0.60) will be explained.

[0159] First, a TaC target is placed on an arc evaporation source within the apparatus, and the substrate temperature is set to 450–600°C, followed by vacuum evaporation. Next, one or both of argon and krypton are introduced, and the pressure within the apparatus is set to 1.0–3.0 Pa. Then, a negative bias of 200–1000 V is applied to the substrate via a DC power supply, and the substrate surface is cleaned for 40 minutes. Afterward, by supplying an arc current of 80–200 A to the cathode electrode, metal ions are generated from the arc evaporation source, thereby forming a TaC crystal structure containing at least 95% by mass in a hexagonal form. 1-y Layer (0.40≤y≤0.60). At this point, in TaC... 1-y In the initial stage of layer formation (within the range of film thickness 0.1 μm or less), the substrate temperature is set to 400–450°C and the substrate bias voltage is set to -50V. As formation progresses, the temperature is gradually increased to 450–550°C and the substrate bias voltage is increased to -60–-75V. For example, an AIP (trade name) manufactured by Kobe Steel Corporation can be cited as an apparatus for arc ion plating.

[0160] <Rigid Coating Process>

[0161] The manufacturing method of the cutting tool according to this embodiment preferably includes a hard coating layer coating process before the first coating layer coating process described above. The method for forming the hard coating layer is not particularly limited, and existing methods can be used. Specifically, for example, a method for forming a hard coating layer by the PVD method described above can be cited.

[0162] <Other processes>

[0163] The manufacturing method according to this embodiment can include, in addition to the above-described steps, a base layer coating step to form a base layer between the substrate and the first layer, an intermediate layer coating step to form an intermediate layer between the first layer and the rigid coating layer, and a surface layer coating step to form a surface layer on the first layer. When forming other layers such as the base layer, intermediate layer, and surface layer, existing methods can also be used to form these other layers. Specifically, methods for forming these other layers using the PVD method described above can be cited as examples.

[0164] Furthermore, the manufacturing method described in this embodiment can appropriately include steps such as metal bombardment, shot peening, and surface treatment. For example, metal bombardment can be achieved by evaporating a Ti cathode in an argon atmosphere and mixing it with the surface of a substrate to form a mixed layer. For surface treatment, abrasive-based grinding and polishing brushes can be used. More specifically, a method using a medium that adsorbs and retains diamond powder in an elastic material can be used. For example, the SIRIUS-Z manufactured by Fuji Manufacturing Co., Ltd. can be used to perform the aforementioned surface treatments.

[0165] [Note 1]

[0166] The cutting tool disclosed herein is a cutting tool having a substrate and a coating disposed on the substrate.

[0167] The coating comprises MoC 1-x The compound shown is composed of MoC 1-x layer,

[0168] The x value is greater than 0.40 and less than 0.60.

[0169] The MoC 1-x The compound shown is composed of a hexagonal crystal structure.

[0170] [Note 2]

[0171] Preferably, the MoC 1-x The layer does not contain free carbon.

[0172] [Note 3]

[0173] Preferably, the MoC 1-x The film hardness of the layer is 2700 mgf / μm 2 Above and 4200 mgf / μm 2 the following.

[0174] [Note 4]

[0175] Preferably, the MoC 1-x The layer is in contact with the substrate.

[0176] [Note 5]

[0177] The cutting tool disclosed herein is a cutting tool having a substrate and a coating disposed on the substrate.

[0178] The coating comprises TaC 1-y The compound shown is composed of TaC 1-y layer,

[0179] The value of y is greater than 0.40 and less than 0.60.

[0180] The TaC 1-y The compound shown contains more than 95% by mass of a hexagonal crystal structure.

[0181] [Note 6]

[0182] Preferably, the TaC 1-y The layer does not contain free carbon.

[0183] [Note 7]

[0184] Preferably, the TaC 1-y The film hardness of the layer is 2700 mgf / μm 2 Above and 4200 mgf / μm 2 the following.

[0185] [Note 8]

[0186] Preferably, the TaC 1-y The layer is in contact with the substrate.

[0187] Example

[0188] Based on the embodiments, this implementation will be described in more detail. However, this implementation is not limited to these embodiments.

[0189] Example 1

[0190] Making Cutting Tools

[0191] [Samples 1 to 26]

[0192] <Substrate Preparation Process>

[0193] As the substrate, JIS standard K10 hard alloy (shape: JIS standard SEET13T3AGSN-L, CNMG120408N-EG) was prepared. Next, the above substrate was placed in the predetermined position of the arc ion plating apparatus (manufactured by Kobe Steel Corporation, trade name: AIP).

[0194] <First layer (MoC) 1-x (Layer) Coating Process >

[0195] MoC was formed on the above-mentioned substrate by arc ion plating. 1-xThe process is as follows: First, a MoC target is placed on an arc evaporation source within the apparatus, and the substrate temperature is set to 450–600°C, followed by vacuum evaporation. Next, one or both of argon and krypton are introduced, and the pressure within the apparatus is set to 1.0–3.0 Pa. Then, a negative bias of 200–1000 V is applied to the substrate via a DC power supply, and the substrate surface is cleaned for 40 minutes. Afterward, an arc current of 80–200 A is supplied to the cathode electrode to generate metal ions from the arc evaporation source, thereby forming MoC. 1-x Layer (0.40≤x≤0.60). At this point, in MoC... 1-x In the initial stage of layer formation (within the range of film thickness below 0.1 μm), the substrate temperature is set to 400–450 °C and the substrate bias voltage is set to -50 V. As formation progresses, the temperature is gradually increased to 450–550 °C and the substrate bias voltage is increased to -60–-75 V. Through the above method, the film is formed until it meets the "MoC" standards in Tables 1 and 2. 1-x The thickness recorded in the "Thickness" column of the "Layer" indicates the formation of MoC. 1-x Layer. As an apparatus used for arc ion plating, an AIP (trade name) manufactured by Kobe Steel Corporation was used.

[0196] <Base Layer Coating Process>

[0197] For substrates and MoC 1-x Samples (samples 5 and 6) with a substrate layer formed between the layers were subjected to MoC testing. 1-x Before the coating process, a substrate layer was formed on the substrate according to the following steps. First, a target containing the metal composition listed in the column of the substrate layer composition described in Table 1 was placed on the arc evaporation source of the arc ion plating apparatus. Next, the substrate temperature was set to 600°C and the gas pressure inside the apparatus was set to 1 Pa. In the case of the nitride substrate layer (sample 5), a mixture of nitrogen and argon was introduced. In the case of the carbonitride substrate layer (sample 6), a mixture of nitrogen, methane, and argon was introduced as the reaction gas. Then, an arc current of 150 A was supplied to the cathode electrode. By supplying the arc current, metal ions, etc., were generated from the arc evaporation source, thereby forming a substrate layer up to the thickness described in parentheses in Table 1, "Substrate Layer".

[0198] <Rigid Coating Process>

[0199] For substrates and MoC 1-x Samples with a hard coating layer between the layers (samples 7 to 13, 16 to 22, 25, and 26) were subjected to MoC testing. 1-xBefore the coating process, a hard coating layer is formed on the substrate according to the following steps. First, a target containing the metal composition listed in the column of the hard coating layer composition described in Tables 1 and 2 is placed on the arc evaporation source of the arc ion plating apparatus. Next, the substrate temperature is set to 550°C and the gas pressure inside the apparatus is set to 4.0 Pa. In the case of a nitride hard coating layer, nitrogen gas is introduced as the reactant gas. In the case of a carbonitride hard coating layer, a mixture of nitrogen and methane gas is introduced as the reactant gas. In the case of a nitrogen oxide hard coating layer, a mixture of oxygen and nitrogen gas is introduced as the reactant gas. Then, an arc current of 150A is supplied to the cathode electrode. By supplying the arc current, metal ions are generated from the arc evaporation source, and a hard coating layer is formed until the thickness is as described in parentheses in Tables 1 and 2 for "hard coating layer".

[0200] It should be noted that, in the case of forming a multilayer hard coating, the compounds listed on the left side of Tables 1 and 2 are repeatedly stacked, starting as the first unit layer, then the second unit layer, until the target thickness is achieved, thereby forming a multilayer structure. For example, in sample 11, a first unit layer of TiAlBN with a thickness of 5 nm and a second unit layer of TiSiN with a thickness of 5 nm are repeatedly and alternately stacked, thereby forming a multilayer structure with a thickness of 1.0 μm.

[0201] <Surface coating process>

[0202] For MoC 1-x Samples (samples 5, 7, 8, 11, and 12) with a surface layer on top were subjected to MoC testing. 1-x After the layer coating process, follow these steps in MoC 1-x A surface layer is formed on top of the base layer. First, a target containing the metal composition listed in the column for the surface layer composition described in Table 1 is placed on the arc evaporation source of the arc ion plating apparatus. Next, the substrate temperature is set to 550°C and the gas pressure inside the apparatus is set to 4.0 Pa. In the case of a nitride surface layer, a mixture of nitrogen and argon is introduced as the reaction gas. Then, an arc current of 150 A is supplied to the cathode electrode. By supplying the arc current, metal ions are generated from the arc evaporation source, and a surface layer is formed up to the thickness described in parentheses in Table 1 for the "surface layer" section.

[0203] [Sample 1-1]

[0204] As a substrate, the same substrate as sample 1 was prepared. MoC was formed on this substrate by arc ion plating. 1-xThe process is as follows: First, a MoC target is placed on the arc evaporation source of an arc ion plating apparatus. Next, the substrate temperature is set to 390°C, and the pressure within the apparatus is set to 2 Pa. Argon gas is introduced as the gas. Then, while maintaining the substrate bias voltage at -50V, an arc current of 120A is directly supplied to the cathode electrode. By supplying the arc current, metal ions are generated from the arc evaporation source, thereby forming MoC. 1-x The cutting tool was obtained by layering.

[0205] [Samples 1-2]

[0206] As a substrate, the same substrate as sample 1 was prepared. MoC was formed on this substrate by arc ion plating. 1-x The process is as follows: First, a MoC target is placed on the arc evaporation source of an arc ion plating apparatus. Next, the substrate temperature is set to 620°C, and the pressure within the apparatus is set to 0.5 Pa. Argon gas is introduced as the gas. Then, while maintaining the substrate bias voltage at -40V, an arc current of 130A is directly supplied to the cathode electrode. By supplying the arc current, metal ions are generated from the arc evaporation source, thereby forming MoC. 1-x The cutting tool was obtained by layering.

[0207] [Samples 1-3]

[0208] As a substrate, a substrate identical to that of sample 1 was prepared. WC was formed on this substrate using the method described in Patent Document 1. 0.56 The cutting tool was obtained by layering.

[0209] [Samples 1-4]

[0210] As a substrate, the same substrate as sample 1 was prepared. On this substrate, a TiN layer (substrate layer) and an AlTiN layer were formed in the aforementioned order. The TiN layer was formed using the same method as sample 5. The AlTiN layer was formed using the same method as the first unit layer of sample 12.

[0211] Evaluation of Cutting Tool Characteristics

[0212] MoC for each sample prepared as described above 1-x The composition x, crystal structure and its content, presence or absence of free carbon, and hardness were measured in the layers. Regarding hardness, the hardness of the hard coating layer was measured in samples 1-3 and 1-4. Since the specific measurement method is described in Embodiment 1, it will not be repeated. The results are shown in Tables 1 and 2, “MoC…”. 1-xThe "composition x", "crystal structure", "content (mass%)", "free carbon", and "hardness (mgf / μm)" of the "layer" are also considered. 2 In the "Free Carbon" column of Tables 1 and 2, the statement "None" indicates that in MoC 1-x The layer does not contain free carbon; the statement "yes" indicates that it exists in MoC. 1-x The layer contains free carbon. MoC was confirmed to be present in samples 1 to 26, sample 1-1, and sample 1-2. 1-x The layer consists of a 100% by mass hexagonal crystal structure.

[0213] MoC was determined 1-x The layers, substrate layer, hard coating layer (first unit layer, second unit layer), and coating thickness are described. Since the specific measurement method is described in Embodiment 1, it will not be repeated. The results are shown in Tables 1 and 2. In Tables 1 and 2, the "-" in "substrate layer" and "hard coating layer" indicates that there is no equivalent layer in the coating. Furthermore, the descriptions such as "TiAlBN (5nm) / TiSiN (5nm) multilayer structure (1.0μm)" in "hard coating layer" indicate that the hard coating layer is formed by alternately stacking a 5nm thick TiAlBN layer (first unit layer) and a 5nm thick TiSiN layer (second unit layer) in a multilayer structure (total thickness 1.0μm).

[0214]

[0215]

[0216] Cutting Test 1

[0217] Using cutting tools prepared as described above, the cutting time until tool breakage was measured under the following cutting conditions to evaluate the tool's resistance to breakage. The following cutting conditions correspond to high-speed, high-efficiency machining with high loads. The results are shown in Tables 1 and 2. A longer cutting time indicates better resistance to breakage.

[0218] (Cutting conditions for the damage resistance test (front milling test))

[0219] End mill insert: SEET13T3AGSN-L

[0220] Material being cut: Ti-6Al-4V

[0221] Speed: 70m / min

[0222] Feed: 0.1mm / blade

[0223] Cutting depth: 5mm, radial cutting depth: 10mm

[0224] Cutting Test 2

[0225] The wear resistance of the cutting tools, prepared as described above, was evaluated by conducting cutting tests under the following cutting conditions. These cutting conditions correspond to high-speed, high-efficiency machining with high loads. The results are shown in Tables 1 and 2. Longer cutting times indicate better wear resistance.

[0226] (Cutting conditions for wear resistance test (outer diameter turning test))

[0227] Milling insert: CNMG120408N-EG

[0228] Material being cut: Ti-6Al-4V

[0229] Speed: 140m / min

[0230] Feed: 0.15mm / blade

[0231] Cutting depth: 0.8mm

[0232] Lifespan assessment criterion: Time when the flank wear exceeds 0.2mm.

[0233] The results of the cutting tests described above confirm that the cutting tools of specimens 1 to 26 of the embodiments, compared with the cutting tools of specimens 1-1 to 1-4 of the comparative examples, exhibit superior resistance to chipping and wear, even in high-speed, high-efficiency machining under high loads, and also have a longer tool life. Therefore, the cutting tools of specimens 1 to 26 of the embodiments are suitable for applications involving high-speed, high-efficiency machining under high loads, and are particularly suitable for applications requiring resistance to chipping and wear.

[0234] Example 2

[0235] Making Cutting Tools

[0236] [Sample 1A to Sample 25A]

[0237] <Substrate Preparation Process>

[0238] As the substrate, JIS standard K10 hard alloy (shape: JIS standard SEET13T3AGSN-L, CNMG120408N-EG) was prepared. Next, the above substrate was placed in the predetermined position of the arc ion plating apparatus (manufactured by Kobe Steel Corporation, trade name: AIP).

[0239] <First layer (TaC) 1-y (Layer) Coating Process >

[0240] TaC was formed on the above-mentioned substrate by arc ion plating. 1-y The process is as follows: First, a TaC target is placed on an arc evaporation source within the apparatus, and the substrate temperature is set to 450–600°C, followed by vacuum evaporation. Next, one or both of argon and krypton are introduced, and the pressure within the apparatus is set to 1.0–3.0 Pa. Then, a negative bias of 200–1000 V is applied to the substrate via a DC power supply, and the substrate surface is cleaned for 40 minutes. Afterward, an arc current of 80–200 A is supplied to the cathode electrode to generate metal ions from the arc evaporation source, thereby forming a TaC crystal structure containing more than 95% by mass in a hexagonal form. 1-y Layer (0.40≤y≤0.60). At this point, in TaC... 1-y In the initial stage of layer formation (within the range of film thickness below 0.1 μm), the substrate temperature is set to 400–450 °C and the substrate bias voltage is set to -50 V. As formation progresses, the temperature is gradually increased to 450–550 °C and the substrate bias voltage is increased to -60–-75 V. Through the above method, the film is processed until it reaches the "TaC" values ​​shown in Tables 3 and 4. 1-y The thickness recorded in the "Thickness" column of the "Layer" indicates the thickness of TaC. 1-y Layer. As an apparatus used for arc ion plating, an AIP (trade name) manufactured by Kobe Steel Corporation was used.

[0241] <Base Layer Coating Process>

[0242] For substrates and TaC 1-y Samples with a substrate layer formed between the layers (sample 5A, sample 6A) were subjected to TaC testing. 1-y Before the coating process, a base layer was formed on the substrate according to the following steps. First, a target containing the metal composition listed in the column of the base layer composition described in Table 3 was placed on the arc evaporation source of the arc ion plating apparatus. Next, the substrate temperature was set to 600°C and the gas pressure inside the apparatus was set to 1 Pa. In the case of the nitride base layer (sample 5A), a mixture of nitrogen and argon was introduced. In the case of the carbonitride base layer (sample 6A), a mixture of nitrogen, methane, and argon was introduced as the reaction gas. Then, an arc current of 150A was supplied to the cathode electrode. By supplying the arc current, metal ions, etc., were generated from the arc evaporation source, and the base layer was formed until the thickness described in parentheses in Table 3 for "base layer" was achieved.

[0243] <Rigid Coating Process>

[0244] For substrates and TaC1-y Samples with a rigid coating layer between the layers (samples 7A to 13A, samples 17A to 25A) were subjected to TaC testing. 1-y Before the coating process, a hard coating layer is formed on the substrate according to the following steps. First, a target containing the metal composition listed in the column of the hard coating layer composition described in Tables 3 and 4 is placed on the arc evaporation source of the arc ion plating apparatus. Next, the substrate temperature is set to 550°C and the gas pressure inside the apparatus is set to 4.0 Pa. In the case of a nitride hard coating layer, a mixture of nitrogen and argon is introduced as the reactant gas. In the case of a carbonitride hard coating layer, a mixture of nitrogen and methane is introduced as the reactant gas. In the case of a nitride hard coating layer, a mixture of oxygen and nitrogen is introduced as the reactant gas. Then, an arc current of 150A is supplied to the cathode electrode. By supplying the arc current, metal ions are generated from the arc evaporation source, and a hard coating layer is formed until the thickness is as described in parentheses in Tables 3 and 4 for "hard coating layer".

[0245] It should be noted that, in the case of forming a multilayer hard coating, the compounds listed on the left side of Tables 3 and 4 are stacked sequentially as the first unit layer, the second unit layer, and so on, until the desired thickness is achieved, thereby forming a multilayer structure. For example, in sample 11A, a first unit layer of TiAlBN with a thickness of 6 nm and a second unit layer of TiSiN with a thickness of 6 nm are stacked alternately, thereby forming a multilayer structure with a thickness of 1.0 μm.

[0246] <Surface coating process>

[0247] For TaC 1-y Samples (sample 5A, sample 7A, sample 8A, sample 11A, and sample 12A) with a surface layer on top were subjected to TaC testing. 1-y After the layer coating process, follow these steps in TaC 1-y A surface layer was formed on top of the base layer. First, a target containing the metal composition listed in the column for the surface layer composition described in Table 3 was placed on the arc evaporation source of the arc ion plating apparatus. Next, the substrate temperature was set to 550°C and the gas pressure inside the apparatus was set to 4.0 Pa. In the case of a nitride surface layer, a mixture of nitrogen and argon was introduced as the reaction gas. Then, an arc current of 150 A was supplied to the cathode electrode. By supplying the arc current, metal ions were generated from the arc evaporation source, and a surface layer was formed up to the thickness described in parentheses in Table 3 for the "surface layer" section.

[0248] [Sample 1-1A]

[0249] As the substrate, a substrate identical to that of sample 1A was prepared. On this substrate, TaC was deposited using an arc ion plating method. 1-y The process is as follows: First, a TaC target is placed on the arc evaporation source of an arc ion plating apparatus. Next, the substrate temperature is set to 380°C, and the pressure within the apparatus is set to 1.5 Pa. Argon gas is introduced as the gas. Then, while maintaining the substrate bias at -55V, an arc current of 120A is directly supplied to the cathode electrode. By supplying the arc current, metal ions are generated from the arc evaporation source, thereby forming TaC. 1-y The cutting tool was obtained by layering.

[0250] [Sample 1-2A]

[0251] As the substrate, a substrate identical to that of sample 1A was prepared. On this substrate, TaC was deposited using an arc ion plating method. 1-y The process is as follows: First, a TaC target is placed on the arc evaporation source of an arc ion plating apparatus. Next, the substrate temperature is set to 610°C, and the pressure within the apparatus is set to 0.8 Pa. Argon gas is introduced as the gas. Then, while maintaining the substrate bias at -43V, an arc current of 120A is directly supplied to the cathode electrode. By supplying the arc current, metal ions are generated from the arc evaporation source, thereby forming TaC. 1-y The cutting tool was obtained by layering.

[0252] [Sample 1-3A]

[0253] As a substrate, a substrate identical to that of sample 1A was prepared. WC was formed on this substrate using the method described in Patent Document 1. 0.56 The cutting tool was obtained by layering.

[0254] [Sample 1-4A]

[0255] As a substrate, the same substrate as that used in sample 1A was prepared. A TiN layer (substrate layer) and an AlTiN layer were formed on this substrate in the aforementioned order. The TiN layer was formed using the same method as that used in sample 5A. The AlTiN layer was formed using the same method as that used in the first unit layer of sample 12A.

[0256] [Samples 1-5A]

[0257] As the substrate, a substrate identical to that of sample 1A was prepared. On this substrate, TaC was deposited using an arc ion plating method. 1-yThe process is as follows: First, a TaC target is placed on the arc evaporation source of an arc ion plating apparatus. Next, the substrate temperature is set to 420°C, and the pressure within the apparatus is set to 1 Pa. Argon gas is introduced as the gas. Then, while maintaining the substrate bias at -69V, an arc current of 120A is directly supplied to the cathode electrode. By supplying the arc current, metal ions are generated from the arc evaporation source, thereby forming TaC. 1-y The cutting tool was obtained by layering.

[0258] Evaluation of Cutting Tool Characteristics

[0259] TaC for each sample prepared as described above 1-y Layer, composition γ, crystal structure, hexagonal TaC were determined. 1-y The content of TaC, the presence or absence of free carbon, and hardness. Since the specific measurement methods are described in Embodiment 1, they will not be repeated here. The results are shown in Tables 3 and 4 under "TaC". 1-y The composition of the "layer" includes its "y", "crystal structure", "hexagonal crystal content (mass%)", "free carbon", and "hardness (mgf / μm)". 2 In the “Crystal Structure” column of Tables 3 and 4, the description of “hexagonal + cubic” indicates that in TaC… 1-y The layer contains hexagonal TaC crystals. 1-y TaC with cubic crystals 1-y In Tables 3 and 4, the "None" designation in the "Free Carbon" column indicates that the free carbon content is within the acceptable range (TaC). 1-y The layer does not contain free carbon; the statement "yes" indicates that it contains TaC. 1-y The layer contains free carbon.

[0260] TaC was determined 1-y The layers, substrate layer, hard coating layer (first unit layer, second unit layer), and coating thickness are described. Since the specific measurement method is described in Embodiment 1, it will not be repeated. The results are shown in Tables 3 and 4. In Tables 3 and 4, the "-" in "substrate layer" and "hard coating layer" indicates that there is no equivalent layer in the coating. Furthermore, the descriptions such as "TiAlBN (6nm) / TiSiN (6nm) multilayer structure (1.0μm)" in "hard coating layer" indicate that the hard coating layer is formed by alternately stacking a 6nm thick TiAlBN layer (first unit layer) and a 6nm thick TiSiN layer (second unit layer) in a multilayer structure (total thickness 1.0μm).

[0261]

[0262]

[0263] Cutting Test 1

[0264] Using cutting tools prepared as described above, the cutting time until tool breakage was measured under the same cutting conditions as in cutting test 1 of Example 1, and the tool's resistance to breakage was evaluated. These cutting conditions correspond to high-speed, high-efficiency machining. The results are shown in Tables 3 and 4. A longer cutting time indicates better resistance to breakage.

[0265] Cutting Test 2

[0266] Using the cutting tools prepared as described above, cutting tests were conducted under the same cutting conditions as cutting test 2 in Example 1 to evaluate the wear resistance of the cutting tools. These cutting conditions correspond to high-speed, high-efficiency machining. The results are shown in Tables 3 and 4. Longer cutting times indicate better wear resistance.

[0267] The results of the cutting tests confirmed that the cutting tools of specimens 1A to 25A, corresponding to the embodiments, exhibit superior resistance to chipping and wear compared to the cutting tools of specimens 1-1A to 1-5A, corresponding to the comparative examples, even in high-speed, high-efficiency machining, and also have a longer tool life. Therefore, the cutting tools of specimens 1A to 25A, corresponding to the embodiments, are suitable for applications involving high-speed, high-efficiency machining under high loads, and are particularly suitable for applications requiring resistance to chipping and wear.

[0268] As described above, the embodiments and examples of the present invention have been explained. However, it is also intended from the outset that the above-described embodiments and examples can be appropriately combined.

[0269] The embodiments and examples disclosed herein should be considered exemplary in all respects, and not restrictive. The scope of the invention is defined not by the foregoing embodiments and examples, but by the claims, and is intended to include all modifications equivalent to and within the scope of the claims.

[0270] Explanation of reference numerals in the attached figures

[0271] 1: Front face;

[0272] 2: Back face;

[0273] 3: The edge of the blade;

[0274] 4: Lamination;

[0275] 10: Cutting tools;

[0276] 11: Substrate;

[0277] 12: First layer;

[0278] 13: Rigid coating layer;

[0279] 131: First unit layer;

[0280] 132: Second unit layer.

Claims

1. A cutting tool comprising a substrate and a coating disposed on the substrate, wherein, The coating comprises a first layer. The first layer is composed of MoC 1-x Layer or TaC 1-y The MoC layer structure 1-x Layers composed of MoC 1-x The compound shown is composed of TaC 1-y Layer by TaC 1-y The compound shown is composed of, The MoC 1-x The compound shown is composed of a hexagonal crystal structure. The x value is greater than 0.40 and less than 0.

60. The TaC 1-y The compound shown contains more than 95% by mass of a hexagonal crystal structure. The value of y is greater than 0.40 and less than 0.

60.

2. The cutting tool according to claim 1, wherein, The first layer does not contain free carbon.

3. The cutting tool according to claim 1 or 2, wherein, The hardness of the first layer is 2700 mgf / μm. 2 Above and 4200 mgf / μm 2 the following.

4. The cutting tool according to claim 1 or 2, wherein, The first layer is in contact with the substrate.

5. The cutting tool according to claim 1, wherein, The coating further includes a rigid coating layer disposed between the substrate and the first layer. The rigid coating layer comprises a first unit layer. The composition of the first unit layer is different from that of the first layer. The first unit layer is composed of at least one element selected from the group consisting of elements of Group 4, Group 5, Group 6, aluminum, and silicon in the periodic table, or is composed of a compound consisting of at least one element selected from the group consisting of elements of Group 4, Group 5, Group 6, aluminum, and silicon in the periodic table and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron.

6. The cutting tool according to claim 5, wherein, The rigid coating layer is composed of the first unit layer. The thickness of the first unit layer is greater than 0.1 μm and less than 15 μm.

7. The cutting tool according to claim 5, wherein, The rigid coating layer further comprises a second unit layer. The composition of the second unit layer differs from that of the first layer and the composition of the first unit layer. The second unit layer is composed of at least one element selected from the group consisting of elements from Group 4, Group 5, Group 6 of the periodic table, aluminum, and silicon, or a compound composed of at least one element selected from the group consisting of elements from Group 4, Group 5, Group 6 of the periodic table, aluminum, and silicon, and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron. The first unit layer and the second unit layer form a multi-layer structure with one or more layers stacked alternately.

8. The cutting tool according to claim 7, wherein, The thickness of the first unit layer is greater than 1 nm and less than 100 nm. The thickness of the second unit layer is greater than 1 nm and less than 100 nm.

9. The cutting tool according to claim 7 or 8, wherein, The thickness of the first layer is greater than 0.1 μm and less than 10 μm. The thickness of the rigid coating layer is greater than 0.1 μm and less than 10 μm.

10. The cutting tool according to claim 9, wherein, The thickness of the coating is greater than 0.2 μm and less than 20 μm.

11. The cutting tool according to claim 1 or 2, wherein, The substrate comprises at least one selected from the group consisting of cemented carbide, cermet, high-speed steel, ceramic, cubic boron nitride sintered body, and diamond sintered body.

12. The cutting tool according to claim 1, wherein, The first layer is composed of MoC 1-x The MoC layer structure 1-x Layers composed of MoC 1-x The compound shown is composed of, The coating consists of a first layer.

13. The cutting tool according to claim 1, wherein, The first layer is composed of MoC 1-x The MoC layer structure 1-x Layers composed of MoC 1-x The compound shown is composed of, The coating consists of a first layer disposed on the substrate and a surface layer disposed on top of the first layer. The surface layer comprises at least one selected from the group consisting of TiN layer, TiCN layer, ZrB2 layer, TiSiN layer and AlCrN layer.

14. The cutting tool according to claim 1, wherein, The first layer is composed of MoC 1-x The MoC layer structure 1-x Layers composed of MoC 1-x The compound shown is composed of, The coating comprises one or both of the first layer, a base layer disposed between the substrate and the first layer, and a rigid coating layer.

15. The cutting tool according to claim 14, wherein, The rigid coating layer comprises a first unit layer. The composition of the first unit layer is different from that of the first layer. The first unit layer is composed of at least one element selected from the group consisting of elements of Group 4, Group 5, Group 6, aluminum, and silicon in the periodic table, or is composed of a compound consisting of at least one element selected from the group consisting of elements of Group 4, Group 5, Group 6, aluminum, and silicon in the periodic table and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron.

16. The cutting tool according to claim 14 or 15, wherein, The substrate layer comprises at least one selected from the group consisting of TiN layer, TiCN layer, ZrB2 layer, TiSiN layer and AlCrN layer.

17. The cutting tool according to claim 1 or 2, wherein, The first layer is composed of TaC 1-y The TaC is composed of layers. 1-y Layer by TaC 1-y The compound shown is composed of, The coating includes a first layer and a rigid coating layer disposed between the substrate and the first layer. The rigid coating layer comprises a first unit layer. The composition of the first unit layer is different from that of the first layer. The first unit layer is composed of at least one element selected from the group consisting of elements of Group 4, Group 5, Group 6, aluminum, and silicon in the periodic table, or is composed of a compound consisting of at least one element selected from the group consisting of elements of Group 4, Group 5, Group 6, aluminum, and silicon in the periodic table and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron.

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