Cutting tool

Abstract

A cutting tool comprising a base material and a coating provided on the base material, wherein the coating includes a first layer, and the first layer contains Al a Ti b Cr (1-a-b-c-d) Si c Ag d and N, and a, b, c, and d satisfy 0.50 ≦ a ≦ 0.75, 0.10 ≦ b ≦ 0.25, 0.005 ≦ c ≦ 0.20, 0.005 ≦ d < 0.10, and a + b + c + d < 1, which is a cutting tool.

Description

Technical Field

[0001] The present disclosure relates to a cutting tool.

Background Art

[0002] Conventionally, a cutting tool including a base material and a coating disposed on the base material has been used for cutting (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The cutting tool of the present disclosure is a cutting tool including a base material and a coating provided on the base material, wherein the coating includes a first layer, the first layer is composed of Al a Ti b Cr (1-a-b-c-d) Si c Ag d N, wherein a, b, c, and d satisfy 0.50 ≦ a ≦ 0.75, 0.10 ≦ b ≦ 0.25, 0.005 ≦ c ≦ 0.20, 0.005 ≦ d < 0.10, and a + b + c + d < 1, and is a cutting tool.

Brief Description of the Drawings

[0005]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0006] [Problems to be Solved by the Present Disclosure] In recent years, the workpieces to be machined have become diversified, and particularly in the fields of aircraft and medicine, the cutting of nickel-based alloys, which are called difficult-to-cut materials, has been increasing. When continuously machining a nickel-based alloy using a cutting tool, the cutting edge temperature becomes high, and the life of the cutting tool is shortened. Therefore, there is a demand for a cutting tool that can have a long tool life, particularly even in the continuous machining of nickel-based alloys.

[0007] Therefore, an object of the present disclosure is to provide a cutting tool that can have a long tool life, particularly even in the continuous machining of nickel-based alloys.

[0008] [Effects of the Present Disclosure] According to the present disclosure, it is possible to provide a cutting tool that can have a long tool life, particularly even in the continuous machining of nickel-based alloys.

[0009] [Description of Embodiments of the Present Disclosure] First, the embodiments of the present disclosure will be listed and described. (1) The cutting tool of the present disclosure is a cutting tool including a base material and a coating provided on the base material, the coating includes a first layer, the first layer is Al a Tib Cr (1-a-b-c-d) Si c Ag d consisting of N, wherein said a, said b, said c and said d are 0.50 ≦ a ≦ 0.75, 0.10 ≦ b ≦ 0.25, 0.005 ≦ c ≦ 0.20, 0.005 ≦ d < 0.10, and a + b + c + d < 1, and is a cutting tool.

[0010] According to the present disclosure, particularly, it is possible to provide a cutting tool that can have a long tool life even in continuous machining of nickel-based alloys.

[0011] (2) In the above (1), said c and said d may satisfy the relationship of c / d ≧ 1. According to this, the tool life is further improved.

[0012] (3) In the above (1) or (2), the thickness of the first layer may be 0.5 μm or more and 10 μm or less. According to this, the tool life is further improved.

[0013] (4) In any one of the above (1) to (3), the coating further includes a second layer provided between the base material and the first layer, wherein the second layer consists of at least one element selected from the first group consisting of group 4 elements, group 5 elements, group 6 elements, aluminum, and silicon in the periodic table, or may consist of a first compound composed of at least one element selected from the first group and at least one element selected from the second group consisting of carbon, nitrogen, oxygen, and boron.

[0014] According to this, the tool life is further improved.

[0015] (5) In any one of the above (1) to (4), the coating further includes a third layer provided on the side opposite to the base material of the first layer, The third layer is made of at least one element selected from the first group consisting of Group 4 elements, Group 5 elements, Group 6 elements, aluminum, and silicon of the periodic table, or may be made of a second compound composed of at least one element selected from the first group and at least one element selected from the second group consisting of carbon, nitrogen, oxygen, and boron.

[0016] According to this, the tool life is further improved.

[0017] (6) In any of (1) to (5) above, the thickness of the coating may be 0.5 μm or more and 12 μm or less. According to this, the tool life is further improved.

[0018] (7) In any of (1) to (6) above, the base material may be made of cemented carbide, cermet, cubic boron nitride sintered body, diamond sintered body, high speed steel, or ceramics. According to this, the tool life is further improved.

[0019] [Details of Embodiments of the Present Disclosure] Specific examples of the cutting tool of the present disclosure will be described below with reference to the drawings. In the drawings of the present disclosure, the same reference numerals represent the same parts or corresponding parts. Also, dimensional relationships such as length, width, thickness, and depth are appropriately changed for the sake of clarity and simplification of the drawings, and do not necessarily represent actual dimensional relationships.

[0020] In the present disclosure, the notation in the form of "A to B" means A or more and B or less. When there is no unit description for A and there is a unit description only for B, the units of A and B are the same.

[0021] In the present disclosure, when a compound or the like is represented by a chemical formula, when the atomic ratio is not particularly limited, it includes all conventionally known atomic ratios and should not necessarily be limited only to those within the stoichiometric range.

[0022] In the present disclosure, when one or more numerical values are described as the lower limit and the upper limit of a numerical range, respectively, any combination of any one numerical value described as the lower limit and any one numerical value described as the upper limit is also considered to be disclosed.

[0023] [Embodiment 1: Cutting Tool] As shown in FIGS. 1 to 4, a cutting tool 1 according to an embodiment of the present disclosure (hereinafter also referred to as "Embodiment 1") includes a base material 2 and a coating 3 provided on the base material 2, and the cutting tool 1 is The coating 3 includes a first layer 13, The first layer 13 contains Al a Ti b Cr (1-a-b-c-d) Si c Ag d and N, where a, b, c, and d are 0.50 ≦ a ≦ 0.75, 0.10 ≦ b ≦ 0.25, 0.005 ≦ c ≦ 0.20, 0.005 ≦ d < 0.10, and a + b + c + d < 1, and the cutting tool 1 satisfies these conditions.

[0024] The cutting tool of Embodiment 1 can have a long tool life, especially in the continuous machining of nickel-based alloys. The reason is presumed as follows.

[0025] Aluminum (Al) contained in the first layer improves the high-temperature hardness of the first layer. When a is 0.50 or more, the high-temperature hardness and heat resistance of the first layer are improved. When a is 0.75 or less, the formation of hexagonal crystals is suppressed, and the decrease in the high-temperature hardness of the first layer is suppressed.

[0026] Titanium (Ti) contained in the first layer improves the high-temperature strength of the first layer. When b is 0.10 or more, the effect of improving the high-temperature strength can be sufficiently obtained. When b is 0.25 or less, the aluminum content of the first layer can be sufficiently ensured, so the high-temperature hardness of the first layer is improved.

[0027] The first layer contains chromium (Cr) and aluminum, thereby improving the heat resistance and high-temperature oxidation resistance of the first layer.

[0028] Silicon (Si) contained in the first layer improves the oxidation resistance and heat resistance of the first layer. When c is 0.005 or more, the oxidation resistance of the first layer is improved. Also, the crystal grains of the first layer are refined, and the hardness of the first layer is improved. When c is 0.20 or less, a decrease in the toughness of the first layer is suppressed, and the occurrence of chipping is suppressed.

[0029] Silver (Ag) contained in the first layer forms an oxide film on the surface of the first layer, improving the lubricity of the coating. Also, silver has low solubility in nickel and chromium which are components of the nickel-based alloy (when the nickel-based alloy is a nickel-chromium alloy). Therefore, the first layer containing silver is less likely to adhere to the work material made of the nickel-based alloy during cutting.

[0030] On the other hand, since silver does not form nitrides, it tends to disrupt the crystal lattice of the coating made of nitrides and lower the hardness of the coating. By adding silver and silicon to the first layer, the hardness of the first layer can be improved. This is a finding discovered as a result of the intensive studies by the present inventors.

[0031] As described above, the first layer of Embodiment 1 can have excellent high-temperature hardness and heat resistance due to aluminum, excellent high-temperature strength due to titanium, excellent oxidation resistance and heat resistance due to chromium and silicon, excellent lubricity and anti-adhesion property due to silver, and high hardness due to the addition of silver and silicon. Even in the continuous machining of nickel-based alloys where the cutting edge tends to become hot during cutting, it can have a long tool life.

[0032] <Cutting tool> As shown in FIGS. 1 to 4, the cutting tool 1 according to Embodiment 1 includes a substrate 2 and a coating 3 provided on the substrate 2. The coating 3 may cover the entire surface of the substrate 2. Also, even if a part of the substrate 2 is not covered with the coating 3 or the configuration of the coating 3 is partially different, it does not deviate from the scope of the present embodiment. The coating 3 may cover at least a portion of the substrate 2 that is involved in cutting. In the present disclosure, the portion of the substrate 2 that is involved in cutting depends on the size and shape of the substrate 2, but in the substrate 2, the cutting edge ridge line and, from the cutting edge ridge line toward the substrate 2 side, a virtual surface where the distance along the perpendicular to the tangent line of the cutting edge ridge line is, for example, any one of 5 mm, 3 mm, 2 mm, 1 mm, and 0.5 mm, and the region surrounded by the virtual surface is meant.

[0033] The cutting tool 1 of the present embodiment can be suitably used as a cutting tool 1 such as a drill, an end mill, a cutting tip for drill with replaceable cutting edge, a cutting tip for end mill with replaceable cutting edge, a cutting tip for milling with replaceable cutting edge, a cutting tip for turning with replaceable cutting edge, a metal saw, a tooth cutting tool, a reamer, a tap, etc.

[0034] FIG. 5 is a perspective view illustrating one aspect of the cutting tool. The cutting tool 1 is used as a cutting tip with replaceable cutting edge. The cutting tool 1 has a rake face 21, a flank face 22, and a cutting edge ridge line 23 where the rake face 21 and the flank face 22 intersect.

[0035] <Substrate> As the substrate, any conventionally known substrate can be used. For example, the substrate may be made of cemented carbide (WC-based cemented carbide, cemented carbide containing WC and Co, cemented carbide obtained by adding carbonitrides such as Ti, Ta, and Nb to WC and Co, etc.), cermet (those mainly composed of TiC, TiN, TiCN, etc.), high-speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, etc.), cubic boron nitride sintered body, or diamond sintered body.

[0036] The substrate may particularly be a WC-based cemented carbide or cermet (particularly a TiCN-based cermet). Since WC-based cemented carbides or cermets are particularly excellent in the balance between hardness and strength at high temperatures, they can contribute to extending the service life of cutting tools when used as the substrate of cutting tools.

[0037] <Coating> ≪Structure of the Coating≫ The coating of Embodiment 1 includes a first layer. By coating the substrate, the coating has the effect of improving various properties such as the wear resistance and chipping resistance of the cutting tool, and bringing about an extended service life of the cutting tool. Note that, in addition to the first layer, the coating can include other layers. Examples of other layers include a second layer 14 provided between the substrate 2 and the first layer 13, and a third layer 16 provided on the side opposite to the substrate 2 of the first layer 13, as shown in FIGS. 2 to 4.

[0038] ≪Thickness of the Coating≫ The thickness of the coating may be 0.4 μm or more and 20 μm or less, may be 0.5 μm or more and 12 μm or less, may be 1 μm or more and 10 μm or less, or may be 2 μm or more and 8 μm or less. When the thickness of the coating is 0.5 μm or more, the service life of the cutting tool can be made longer. On the other hand, when the overall thickness of the coating is 12 μm or less, chipping in the coating is less likely to occur at the initial stage of cutting, and the service life of the cutting tool can be made longer.

[0039] The thickness of the coating is measured by observing the cross-section of the coating using a scanning electron microscope (SEM). The specific measurement method is as follows. The cutting tool is cut in the direction along the normal of the main surface of the coating to prepare a cross-section sample. The cross-section sample is observed with an SEM. The observation magnification is set to 5000 to 10000 times, and the measurement field of view is 100 to 500 μm 2 and the thickness widths at three locations of the coating are measured in one field of view, and the average value of the thickness widths at the three locations is calculated. This average value corresponds to the thickness of the coating. The thicknesses of the respective layers described below are also measured in the same manner unless otherwise specified.

[0040] ≪Crystal Structure of the Coating≫ The crystal structure of the coating may be a cubic crystal form. When the crystal structure of the coating is a cubic crystal form, the hardness of the coating is improved. The crystal structure of each layer (the first layer, the third layer, the second layer, etc.) in the coating may be a cubic crystal form. The crystal structure of the coating and each layer in the coating can be analyzed by an X-ray diffractometer known in the art.

[0041] ≪Hardness of the coating≫ The hardness of the coating may be 30 GPa or more and 50 GPa or less, or may be 35 GPa or more and 45 GPa or less. According to this, the coating has sufficient hardness. The hardness of the coating is measured by the nanoindentation method (measurement device: ENT-1100a manufactured by Elionix). Specifically, it is performed by a method conforming to ISO14577, the measurement load is 10 mN (1 gf), the hardness at 10 locations on the surface of the coating is measured, and the average value of the hardness at 10 locations is calculated. The average value corresponds to the hardness of the coating.

[0042] <The first layer> ≪Composition of the first layer≫ The first layer is composed of Al a Ti b Cr (1-a-b-c-d) Si c Ag d N, where a, b, c, and d satisfy 0.50 ≦ a ≦ 0.75, 0.10 ≦ b ≦ 0.25, 0.005 ≦ c ≦ 0.20, 0.005 ≦ d < 0.10, and a + b + c + d < 1.

[0043] a may be 0.500 or more and 0.750 or less, may be 0.550 or more and 0.700 or less, or may be 0.600 or more and 0.650 or less.

[0044] b may be 0.100 or more and 0.250 or less, may be 0.100 or more and 0.200 or less, or may be 0.120 or more and 0.180 or less.

[0045] c may be 0.005 or more and 0.200 or less, may be 0.010 or more and 0.150 or less, or may be 0.050 or more and 0.100 or less.

[0046] d may be 0.005 or more and 0.100 or less, may be 0.010 or more and 0.090 or less, or may be 0.030 or more and 0.080 or less.

[0047] a + b + c + d is less than 1, may be 0.950 or less, may be 0.910 or less, or may be 0.890 or less.

[0048] c / d may be 1 or more, may be more than 1, may be 1 or more and 20 or less, may be 1.2 or more and 10 or less, may be 1.25 or more and 5 or less, or may be 2 or more and 4 or less. When c / d is 1 or more, the film hardness is improved and the tool life is improved.

[0049] In the present disclosure, "the first layer is composed of Al a Ti b Cr (1-a-b-c-d) Si c Ag d N" means that, as long as the effects of the present disclosure are not impaired, the first layer may contain inevitable impurities in addition to Al a Ti b Cr (1-a-b-c-d) Si c Ag d N. Examples of the inevitable impurities include oxygen and carbon. The total content rate of the inevitable impurities in the first layer may be greater than 0 atomic% and less than 1 atomic%. In the present disclosure, "atomic%" means the ratio (%) of the number of atoms to the total number of atoms constituting the layer.

[0050] The contents of a, b, c, d, and the inevitable impurities in the first layer are measured by performing elemental analysis on the cross-section of the coating using a transmission electron microscope (TEM). The specific measurement method is as follows. Cut the cutting tool in the direction along the normal line of the main surface of the coating to prepare a thin sample including the cross-section of the coating. Using EDS (Energy Dispersive X-ray Spectroscopy) attached to the TEM, irradiate the thin sample with an electron beam, measure the energy and the number of occurrences of characteristic X-rays generated at that time, and perform elemental analysis of the first layer. Arbitrarily set five non-overlapping measurement regions in the first layer and perform elemental analysis at the five locations. Obtain the average composition of the five locations. The average composition corresponds to the composition of the first layer. The compositions of the second layer and the third layer described later are also measured by the same method. It has been confirmed that there is no variation in the measurement results even if the measurement locations are arbitrarily selected.

[0051] In the present disclosure, for the composition of the first layer, Al a Ti b Cr (1-a-b-c-d) Si c Ag d in N, the total number of atoms of Al, Ti, Cr, Si, and Ag is A M1 the number of atoms of N with respect to A N1 ratio A N1 / A M1 is 0.8 or more and 1.2 or less. The ratio A N1 / A M1 can be measured by the Rutherford backscattering (RBS) method. If the above ratio A N1 / A M1 is within the above range, it has been confirmed that the effects of the present disclosure are not impaired.

[0052] <Thickness of the first layer> The thickness of the first layer may be 0.4 μm or more and 12 μm or less, may be 0.5 μm or more and 10 μm or less, may be 1 μm or more and 8 μm or less, or may be 2 μm or more and 5 μm or less. When the thickness of the first layer is 0.5 μm or more, the wear resistance is excellent and the life of the cutting tool can be extended. On the other hand, when the thickness of the first layer is 10 μm or less, chipping in the coating is less likely to occur at the initial stage of cutting, and the life of the cutting tool can be extended.

[0053] <Second layer> As shown in FIGS. 2 and 4, the coating 3 can further include a second layer 14 provided between the substrate 2 and the first layer 13. The second layer 14 may be provided directly above the substrate.

[0054] The second layer is composed of at least one element selected from the first group consisting of Group 4 elements, Group 5 elements, Group 6 elements, aluminum (Al), and silicon (Si) of the periodic table, or a first compound composed of at least one element selected from the first group and at least one element selected from the second group consisting of carbon (C), nitrogen (N), oxygen (O), and boron (B). Examples of Group 4 elements of the periodic table include titanium (Ti), zirconium (Zr), hafnium (Hf), etc. Examples of Group 5 elements of the periodic table include vanadium (V), niobium (Nb), tantalum (Ta), etc. Examples of Group 6 elements of the periodic table include chromium (Cr), molybdenum (Mo), tungsten (W), etc. The second layer can enhance the adhesion between the substrate and the coating, and improve the tool life. As long as the effects of the present disclosure are not impaired, the second layer can include unavoidable impurities in addition to at least one element selected from the first group or the first compound.

[0055] The second layer is composed of at least one element selected from Group 1 selected from the above, or a first compound composed of at least one element selected from the above and at least one element selected from the second group consisting of carbon, nitrogen, oxygen, and boron. Group 1 selected from the above and at least one element selected from the second group consisting of carbon, nitrogen, oxygen, and boron.

[0056] Examples of the first compound include TiWCN, TiN, TiAlN, TiAlON, Al2O3, TiAlSiN, TiCrSiN, TiAlCrSiN, AlCrN, AlCrO, AlCrON, AlCrSiN, AlCrBN, TiZrN, TiAlMoN, TiAlNbN, TiSiN, AlCrTaN, AlVN, AlTiVN, TiB2, TiCrHfN, CrSiWN, TiAlCN, TiSiCN, AlZrON, AlCrCN, AlHfN, CrSiBON, TiAlWN, AlCrMoCN, TiCN, TiCON, ZrN, and ZrCN.

[0057] The thickness of the second layer is not particularly limited as long as the effects of the present embodiment are not impaired. For example, it can be 0.1 μm or more and 2 μm or less.

[0058] <Third layer> As shown in FIGS. 3 and 4, the coating 3 can further include a third layer 16 provided on the side opposite to the substrate 2 of the first layer 13. The third layer 16 may be provided directly above the first layer 13. Another layer may be provided between the first layer 13 and the third layer 16. The third layer 16 may be the outermost layer.

[0059] The third layer is made of at least one element selected from Group 1 consisting of Group 4 elements, Group 5 elements, Group 6 elements, aluminum (Al), and silicon (Si) of the periodic table, or a second compound made of at least one element selected from Group 1 and at least one element selected from Group 2 consisting of carbon (C), nitrogen (N), oxygen (O), and boron (B). The third layer can reduce the friction coefficient of the coating and extend the service life of the cutting tool. As long as the effects of the present disclosure are not impaired, the third layer can contain impurities in addition to at least one element selected from Group 1 or the second compound.

[0060] The third layer is made of at least one element selected from Cr, Al, Ti, and Si of the Group 1 selected, or the Group 1It can be composed of a second compound comprising at least one element selected from and at least one element selected from the second group consisting of carbon, nitrogen, oxygen and boron.

[0061] Examples of the second compound include AlTiBN, TiAlN, TiAlON, Al2O3, TiAlSiN, TiCrSiN, TiAlCrSiN, AlCrN, AlCrO, AlCrON, AlCrSiN, AlCrBN, TiZrN, TiAlMoN, TiAlNbN, TiSiN, AlCrTaN, AlVN, AlTiVN, TiB2, TiCrHfN, CrSiWN, TiAlCN, TiSiCN, AlZrON, AlCrCN, AlHfN, CrSiBON, TiAlWN, AlCrMoCN, TiCN, TiCON, ZrN and ZrCN.

[0062] The thickness of the third layer may be 0.1 μm or more and 2 μm or less. When the thickness of the third layer is 0.1 μm or more, the effect of imparting lubricity by the third layer is easily obtained. Although the upper limit of the thickness of the third layer is not particularly limited, when it exceeds 2 μm, there is a tendency that the above-described effect of imparting lubricity cannot be further improved. Therefore, considering the cost aspect, the thickness of the third layer may be 2 μm or less.

[0063] <Intermediate layer> The coating can include an intermediate layer provided between the third layer and the first layer or between the first layer and the second layer. Examples of the intermediate layer include TiAlCeN, AlTiN, AlTiBN, AlTiSiN, AlTiYN, AlTiLaN, etc. The thickness of the intermediate layer may be 0.1 μm or more and 2 μm or less, may be 0.3 μm or more and 1.5 μm or less, or may be 0.4 μm or more and 1.0 μm or less.

[0064] [Embodiment 2: Method for manufacturing a cutting tool] In Embodiment 2, the method for manufacturing the cutting tool of Embodiment 1 will be described. The manufacturing method includes a first step of preparing a base material and a second step of forming a coating on the base material. The second step includes a step of forming the first layer. Details of each step will be described below.

[0065] <Step 1> In Step 1, a substrate is prepared. As the substrate, the substrate described in Embodiment 1 can be used. Any conventionally known substrate can be prepared.

[0066] <Step 2> In Step 2, a film is formed on the substrate. Step 2 includes a step of forming a first layer.

[0067] In the step of forming the first layer, the first layer is formed using a Physical Vapor Deposition (PVD) method. In order to improve the wear resistance of the film including the first layer, it is highly effective to form a layer made of a highly crystalline compound. As a result of examining various methods as the method for forming the first layer, the present inventors have found that the use of a physical vapor deposition method is highly effective.

[0068] As the PVD method, at least one selected from the group consisting of a cathodic arc ion plating method, a balanced magnetron sputtering method, an unbalanced magnetron sputtering method, and a HiPIMS method can be used. In particular, a cathodic arc ion plating method with a high ionization rate of raw material elements may be used. When the cathodic arc ion plating method is used, since ion bombardment treatment of a metal can be performed on the surface of the substrate before forming the first layer, the adhesion between the substrate and the film including the first layer is remarkably improved.

[0069] The cathodic arc ion plating method can be performed, for example, by installing a substrate in a device and a target as a cathode, and then applying a high voltage to the target to generate an arc discharge to ionize and evaporate the atoms constituting the target, and depositing a substance on the substrate.

[0070] <Other Steps> In addition to the step of forming the first layer, the second step can include surface treatment steps such as surface grinding and shot blasting. Further, the second step can include steps of forming other layers such as a second layer, a third layer, and an intermediate layer. The other layers can be formed by conventionally known chemical vapor deposition methods or physical vapor deposition methods. From the viewpoint that other layers can be continuously formed with the first layer in one physical vapor deposition apparatus, the other layers may be formed by physical vapor deposition methods.

Example

[0071] The present embodiment will be described more specifically with reference to examples. However, the present embodiment is not limited by these examples.

[0072] ≪Manufacture of cutting tool≫ FIG. 6 is a schematic cross-sectional view of the cathode arc ion plating apparatus used in this example, and FIG. 7 is a schematic top view of the apparatus of FIG. 6.

[0073] In the apparatuses of FIGS. 6 and 7, in the chamber 101, cathodes 106 and 107 for the first layer, which are alloy targets serving as metal raw materials for the coating 3, and a rotary substrate holder 104 for installing the substrate are attached. The compositions of the cathodes 106 and 107 are adjusted so as to obtain the compositions shown in Table 1 below.

[0074] In the apparatus for a sample on which the second layer or the third layer is to be formed, in the chamber 101, a cathode for the second layer or a cathode for the third layer (not shown) is further attached. The compositions of the cathode for the second layer and the cathode for the third layer are adjusted so as to obtain the compositions shown in Table 2 below.

[0075] An arc power source 108 is attached to the cathode 106, and an arc power source 109 is attached to the cathode 107. Also, a bias power source 110 is attached to the substrate holder 104. Further, a gas inlet for introducing the gas 105 is provided in the chamber 101, and a gas outlet 103 is provided to adjust the pressure in the chamber 101. The structure is such that the gas in the chamber 101 can be sucked by a vacuum pump from the gas outlet 103.

[0076] A chip with a grade of carbide alloy of JIS standard K20 and a shape of JIS standard CNMG120408 was mounted on the substrate holder 104 as the substrate.

[0077] Next, the inside of the chamber 101 was evacuated by a vacuum pump, and while rotating the substrate, the temperature was heated to 500 °C by a heater installed in the apparatus, and the pressure in the chamber 101 was reduced to 1.0×10 -4 Pa by evacuation. Next, argon gas was introduced from the gas inlet to maintain the pressure in the chamber 101 at 2.0 Pa, the voltage of the bias power source 110 was gradually increased to -1000 V, and the surface of the substrate was cleaned for 15 minutes. Then, the substrate was cleaned by exhausting argon gas from the chamber 101 (argon bombardment treatment). Thus, the substrates of the cutting tools for each sample were prepared.

[0078] Next, while rotating the substrate at the center, while introducing nitrogen as the reaction gas, while maintaining the temperature of the substrate at 550 °C, the reaction gas pressure at 2.0 Pa, and the voltage of the bias power source 110 at a certain value in the range of -50 V to -300 V, an arc current of 150 A was supplied to the cathodes 106 and 107 respectively, to generate metal ions from the cathodes 106 and 107, and a first layer having the composition shown in Table 1 below was formed on the substrate.

[0079] When the second layer was formed, after forming the second layer on the substrate, the first layer was formed on the second layer. The second layer was formed by the following procedure. The substrate temperature was set to 550 °C and the gas pressure in the apparatus was set to 4.0 Pa. As the reaction gas, a mixed gas of nitrogen gas and argon gas was introduced. Then, an arc current of 150 A was supplied to the cathode electrode. By generating metal ions and the like from the arc evaporation source by the supply of the arc current, the second layer was formed.

[0080] When the third layer was formed, the third layer was formed on the first layer. The third layer was formed by the following procedure. The substrate temperature was set to 550 °C and the gas pressure in the apparatus was set to 4.0 Pa. As the reaction gas, a mixed gas of nitrogen gas and argon gas was introduced. Then, an arc current of 150 A was supplied to the cathode electrode. By generating metal ions and the like from the arc evaporation source by the supply of the arc current, the third layer was formed.

[0081] As described above, cutting tools for each sample were produced.

[0082]

Table 1

[0083]

Table 2

[0084] ≪Evaluation≫ <Measurement of the composition of the first layer> For the cutting tools of each sample, the composition of the first layer was measured by the method described in Embodiment 1. Al of the first layer a Ti b Cr (1-a-b-c-d) Si c Ag d The values of a, b, c, and d in N are shown in Table 1. Further, a + b + c + d and c / d are shown in Table 1.

[0085] <Measurement of the composition of the second layer and the third layer> Regarding the cutting tools of each sample, the compositions of the second layer and the third layer were measured by the method described in Embodiment 1. The results are shown in Table 2. When "-" is described in Table 2, it means that the corresponding layer does not exist.

[0086] <Measurement of the thickness of the first layer, the thickness of the second layer, and the thickness of the third layer> Regarding the cutting tools of each sample, the thickness of the first layer, the thickness of the second layer, and the thickness of the third layer were measured by the method described in Embodiment 1. The results are shown in Tables 1 to 2.

[0087] <Crystal structure of the coating> Regarding the cutting tools of each sample, the crystal structure of the coating was analyzed by the method described in Embodiment 1. In Samples 1 to 21, the crystal structure was cubic.

[0088] <Hardness of the coating> Regarding the cutting tools of each sample, the hardness of the coating was analyzed by the method described in Embodiment 1. In Samples 1 to 21, the hardness of the coating was 30 GPa or more and 50 GPa or less.

[0089] <Cutting test> A continuous turning test was performed under the cutting conditions of each sample, and the cutting distance until the wear width or chipping width of the cutting edge reached 200 μm was measured. The results are shown in Table 2. A longer cutting distance indicates a longer tool life. ≪Cutting conditions≫ Workpiece material: Inconel 718 Cutting speed Vc: 100 m / min Feed rate f: 0.25 mm / rev Depth of cut ap: 2.0 mm · Cutting oil: Yes The above cutting conditions are applicable to the continuous machining of nickel-based alloys.

[0090] The cutting tools of Samples 1 to 21 correspond to the examples, and the cutting tools of Samples 1-1 to 1-11 correspond to the comparative examples. It was confirmed that the cutting tools of Samples 1 to 21 have a longer tool life in the continuous machining of nickel-based alloys compared to the cutting tools of Samples 1-1 to 1-11.

[0091] As described above, the embodiments and examples of the present disclosure have been explained. However, it has been planned from the beginning to appropriately combine or variously modify the configurations of the above-described embodiments and examples. The embodiments and examples disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above-described embodiments and examples, and it is intended that all changes within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0092] 1 Cutting tool, 2 Base material, 3 Coating, 13 First layer, 14 Second layer, 16 Third layer, 21 Rake face, 22 Flank face, 23 Cutting edge ridge line, 101 Chamber, 103 Gas discharge port, 104 Base material holder, 105 Gas, 106, 107 Cathode, 108, 109 Arc power source, 110 Bias power source.

Claims

1. A cutting tool comprising a substrate and a coating provided on the substrate, wherein the coating includes a first layer, The first layer is composed of Al ａ Ti ｂ Cr （１－ａ－ｂ－ｃ－ｄ） Si ｃ Ag ｄ and N wherein a, b, c, and d are 0.50 ≤ a ≤ 0.75, 0.10 ≤ b ≤ 0.25, 0.005 ≤ c ≤ 0.20, 0.005 ≤ d < 0.10, and a + b + c + d < 1, a cutting tool.

2. The cutting tool according to claim 1, wherein c and d satisfy the relationship c / d ≥ 1.

3. The cutting tool according to claim 1 or claim 2, wherein the thickness of the first layer is 0.5 μm or more and 10 μm or less.

4. The coating further includes a second layer provided between the substrate and the first layer, wherein the second layer is composed of at least one element selected from the first group consisting of group 4 elements, group 5 elements, group 6 elements, aluminum, and silicon in the periodic table, or a first compound composed of at least one element selected from the first group and at least one element selected from the second group consisting of carbon, nitrogen, oxygen, and boron, the cutting tool according to claim 1 or claim 2.

5. The coating further includes a third layer provided on the side of the first layer opposite to the substrate, wherein the third layer is composed of at least one element selected from the first group consisting of group 4 elements, group 5 elements, group 6 elements, aluminum, and silicon in the periodic table, or a second compound composed of at least one element selected from the first group and at least one element selected from the second group consisting of carbon, nitrogen, oxygen, and boron, the cutting tool according to claim 1 or claim 2.

6. The cutting tool according to claim 1 or claim 2, wherein the thickness of the coating is 0.5 μm or more and 12 μm or less.

7. The substrate of the cutting tool according to claim 1 or claim 2 is made of cemented carbide, cermet, cubic boron nitride sintered body, diamond sintered body, high speed steel, or ceramics.

Images