Coated tool and cutting tool

Abstract

A coated tool according to a non-limiting aspect of the present disclosure comprises a base and a coating layer positioned on a surface of the base. The coating layer has a Ti-based coating layer. The Ti-based coating layer is in contact with the base. The base has a crack extending from the surface towards the interior of the base. A portion of the Ti-based coating layer is in the crack.

Description

Coated tools and cutting tools CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2023-031807, filed on March 2, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to coated tools and cutting tools.

[0003] A coated tool (surface-coated sintered alloy) described in Japanese Patent No. 4043145 (Patent Document 1) is known as a coated tool used for cutting tools, etc. The coated tool described in Patent Document 1 has a base material surface coated with a hard film. A diffusion element-containing layer containing an iron-group metal and tungsten diffused therein is formed in the hard film.

[0004] A non-limiting aspect of the coated tool of the present disclosure is a coated tool including a substrate and a coating layer located on the surface of the substrate. The coating layer has a Ti-based coating layer. The Ti-based coating layer is in contact with the substrate. The substrate has a crack extending from the surface toward the inside of the substrate. A portion of the Ti-based coating layer is present in the crack.

[0005] Fig. 2 is a perspective view showing a non-limiting one-sided coated tool of the present disclosure. Fig. 3 is a cross-sectional view perpendicular to the surface of the substrate in the coated tool shown in Fig. 1. Fig. 4 is an enlarged view of the vicinity of the boundary between the substrate and the Ti-based coating layer shown in Fig. 2. Fig. 5 is a perspective view showing a non-limiting one-sided cutting tool of the present disclosure.

[0006] <Coated Tool> A non-limiting aspect of the coated tool 1 of the present disclosure will be described in detail below with reference to the drawings. However, for the sake of convenience, the drawings referred to below show only the main components necessary for explaining the embodiment in a simplified form. Therefore, the coated tool 1 may include any components not shown in the drawings referred to. Furthermore, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the components and the dimensional ratios of the components.

[0007] The coated tool 1 may comprise a substrate 3 and a coating layer 7 located on a surface 5 of the substrate 3, as a non-limiting example shown in FIGS.

[0008] The coating layer 7 may have a Ti-based coating layer 9 (titanium-based coating layer). The Ti-based coating layer 9 may be in contact with the substrate 3. In other words, the Ti-based coating layer 9 may be coated adjacent to the substrate 3. The Ti-based coating layer 9 may also be called an underlayer.

[0009] The substrate 3 may have a crack 11, as shown in a non-limiting example in Fig. 3. The crack 11 may extend from the surface 5 of the substrate 3 toward the interior of the substrate 3. A part of the Ti-based coating layer 9 may be present in the crack 11. In these cases, the adhesion between the substrate 3 and the coating layer 7 is likely to be improved, and chipping resistance and wear resistance are likely to be improved. Therefore, the coated tool 1 has high wear resistance and fracture resistance.

[0010] The phrase "a part of the Ti-based coating layer 9 is present in the crack 11" may mean that a portion that is continuous with the Ti-based coating layer 9 and has the same composition as the Ti-based coating layer 9 is located inside the crack 11. "Having the same composition" may mean that the difference in the respective constituent components is 5% or less. The difference in the constituent components may be 3% or less, or may be 1% or less.

[0011] For example, if the gas forming the Ti-based coating layer 9 is allowed to penetrate into the cracks 11 during the formation of the Ti-based coating layer 9, a portion of the Ti-based coating layer 9 is likely to be present in the cracks 11. Therefore, the configuration in which a portion of the Ti-based coating layer 9 is present in the cracks 11 can also be rephrased as a portion of the Ti-based coating layer 9 penetrating into the cracks 11. The cracks 11 can also be rephrased as fissures. The cracks 11 may open on the surface 5 of the substrate 3.

[0012] The presence of a portion of the Ti-based coating layer 9 in the crack 11 may be confirmed by, for example, Auger Electron Spectroscopy (AES). Specifically, it may be confirmed by cross-sectional observation using an EDS (Energy Dispersive X-ray Spectroscopy) attached to an electron microscope. Examples of electron microscopes include a scanning electron microscope (SEM) and a transmission electron microscope (TEM).

[0013] When a cross-sectional observation reveals that a recess is formed from the surface 5 of the substrate 3 toward the interior of the substrate 3, the recess being 0.05 to 3 μm in width and having a depth at least twice the width, this recess can be said to be a crack.

[0014] The cross section in the cross-sectional observation may be a cross section perpendicular to the surface 5 of the substrate 3. The area ratio of the Ti-based coating layer 9 inside the crack 11 in the cross section perpendicular to the surface 5 of the substrate 3 may be evaluated. When this area ratio is 100%, it means that the Ti-based coating layer 9 is present throughout the entire inside of the crack 11. For example, when the area ratio is 30% or more, it may be considered that a portion of the Ti-based coating layer 9 is present in the crack 11. Note that there is no particular upper limit to the area ratio. For example, there is no problem even if the area ratio is 100%.

[0015] The substrate 3 may have a first region 13 extending inward from the surface 5. The first region 13 may have a thickness of 0.5 to 30 μm. The crack 11 may be located in the first region 13.

[0016] The substrate 3 may have a plurality of cracks 11. A portion of the Ti-based coating layer 9 may be present in each of the plurality of cracks 11. In these cases, the adhesion between the substrate 3 and the coating layer 7 is likely to be improved.

[0017] The number of cracks 11 may be measured by cross-sectional observation using an electron microscope. For example, a cross section perpendicular to the surface 5 of the substrate 3 may be photographed at a magnification of 10,000 times using an electron microscope, and the number of cracks 11 present in an area of ​​8.9 μm × 11.8 μm in the obtained electron microscope photograph may be measured. The number of photographed locations may be multiple. For example, the number of photographed locations may be five. The number of cracks 11 may be 1 to 3 per field of view in the electron microscope photograph.

[0018] In a cross section perpendicular to the surface 5 of the substrate 3, the crack 11 may have a bent portion as shown in a non-limiting example in Figure 3. In this case, the adhesion between the substrate 3 and the coating layer 7 is likely to be improved. In particular, when the crack 11 is bent so as to approach parallel to the surface 5 of the substrate 3, the adhesion between the substrate 3 and the coating layer 7 is likely to be further improved.

[0019] The length of the crack 11 may be the dimension of the crack 11 in the direction in which the crack 11 extends (longitudinal direction). The width of the crack 11 may be the dimension of the crack 11 in the direction perpendicular to the direction in which the crack 11 extends (transverse direction). The length of the crack 11 may be, for example, 0.5 to 15 μm. The width of the crack 11 may be, for example, 0.05 to 3 μm as described above. When the base 3 has a plurality of cracks 11, the length and width of the cracks 11 may be average values. The average value may be the average value of two cracks 11.

[0020] The substrate 3 may be a sintered alloy. The sintered alloy may be made of a cemented carbide. In other words, the substrate 3 may be made of a cemented carbide. The cemented carbide may contain a hard phase and a binder phase. The hard phase in the cemented carbide may contain, for example, tungsten carbide (WC). The hard phase may contain WC as a main component. In other words, the cemented carbide may be a WC-based cemented carbide. The "main component" may mean a component having the largest mass percentage value compared to other components.

[0021] The binder phase in the cemented carbide may contain an iron group metal. Examples of iron group metals include cobalt (Co) and nickel (Ni). The binder phase in the cemented carbide may contain at least one of Co and Ni. The binder phase in the cemented carbide may contain an iron group metal as a main component. The binder phase may function as a phase that bonds adjacent hard phases.

[0022] The substrate 3 may be made of cemented carbide. In this case, the hard phase may be made of WC or WC and at least one cubic structure compound selected from carbides, nitrides, carbonates, oxynitrides of elements in Groups 4, 5, and 6 of the Periodic Table, and their mutual solid solutions. The binder phase may be mainly composed of Co and / or Ni.

[0023] The substrate 3 may be made of cemented carbide. In this case, the amount of nitrogen (N) contained in the cracks 11 may be 2 mass % or more. In other words, the nitrogen content in the portion of the Ti-based coating layer 9 located in the cracks 11 may be 2 mass % or more. In this case, wear resistance and chipping resistance are likely to be improved. The amount of nitrogen contained in the cracks 11 may be 2 to 30 mass %.

[0024] The amount of carbon (C) contained in the cracks 11 may be 2 to 30 mass %. In other words, the carbon content in the portion of the Ti-based coating layer 9 located in the cracks 11 may be 2 to 30 mass %.

[0025] EDS may be used when analyzing the composition of the cracks 11. In EDS, composition analysis may be performed using an acceleration voltage of 20 kV and selected elements of Ti, C, N, W, and Co. The composition analysis of the cracks 11 may also be performed by cross-sectional observation, or by measuring any five locations and calculating the average value. When the substrate 3 is made of cemented carbide, the cracks 11 to be measured may be located at the boundaries between adjacent WC grains. This point is the same when measuring the number of cracks 11.

[0026] When the substrate 3 is a sintered alloy, the sintered alloy may be made of a cermet. In other words, the substrate 3 may be made of a cermet. The cermet may contain a hard phase and a binder phase. The hard phase in the cermet may contain, for example, a titanium (Ti) compound. Examples of Ti compounds include titanium carbonitride (TiCN), titanium carbide (TiC), and titanium nitride (TiN). The hard phase in the cermet may also contain a Ti compound as a main component. That is, the cermet may be a Ti-based cermet.

[0027] The binder phase in the cermet may contain an iron group metal. The binder phase in the cermet may contain at least one of Co and Ni. The binder phase in the cermet may contain an iron group metal as a main component.

[0028] The composition of the substrate 3 may be measured by, for example, EDS. The measurement may be performed using an EDS attached to an electron microscope.

[0029] The Ti-based coating layer 9 may be a single layer or may have a laminated structure in which multiple layers are stacked. Examples of the composition of the Ti-based coating layer 9 include TiN and TiC. For example, when the Ti-based coating layer 9 is a single layer, the Ti-based coating layer 9 may be a TiN layer.

[0030] When the Ti-based coating layer 9 has a laminated structure, the Ti-based coating layer 9 may have a structure in which three or more TiN layers and TiC layers are alternately laminated. The layer closest to the substrate 3 may be a TiN layer. That is, the Ti-based coating layer 9 may have a laminated structure in which at least three TiN layers and TiC layers are alternately laminated, and the layer closest to the substrate 3 in the laminated structure may be a TiN layer. In these cases, wear resistance and chipping resistance are likely to be improved. The number of laminated layers may be set to 3 to 8.

[0031] The coating layer 7 is not limited to a specific thickness. For example, the average thickness of the Ti-based coating layer 9 may be set to 0.1 to 1 μm. The thickness of the Ti-based coating layer 9 is a value excluding the portion present in the crack 11. Furthermore, when the Ti-based coating layer 9 has a laminated structure, the thickness of the Ti-based coating layer 9 shown as an example is the entire thickness. When the Ti-based coating layer 9 has a laminated structure, the thickness of each layer may be the same or different.

[0032] The thickness of the coating layer 7 may be measured by cross-sectional observation using an electron microscope. For example, the thickness may be measured at 10 or more measurement points at any position on the Ti-based coating layer 9, and the average value may be calculated. This also applies to the other layers described below.

[0033] 2, the coating layer 7 may include, in order from the substrate 3, a Ti-based coating layer 9, a first TiCN layer 15, a second TiCN layer 17, a TiCNO layer 19 (titanium carbonate nitride layer), and an AlO layer 21 (alumina layer). In this case, the life of the coated tool 1 is likely to be longer.

[0034] The first TiCN layer 15 may be a so-called MT (moderate temperature) TiCN layer. The first TiCN layer 15 may have an average thickness of 2 to 15 μm. In this case, the first TiCN layer 15 has high wear resistance and chipping resistance. The titanium carbonitride crystals contained in the first TiCN layer 15 may be columnar crystals elongated in the thickness direction of the coating layer 7. The first TiCN layer 15 may be in contact with the Ti-based coating layer 9.

[0035] The second TiCN layer 17 may be a so-called HT (high temperature)-TiCN layer. The average thickness of the second TiCN layer 17 may be set to 10 to 900 nm. The second TiCN layer 17 may be in contact with the first TiCN layer 15.

[0036] The average thickness of the TiCNO layer 19 may be set to 200 to 2000 nm. In this case, the hardness of the TiCNO layer 19 is less likely to decrease. Also, the Al2O3 layer 21 is more likely to have an α-type crystal structure. The TiCNO layer 19 may be in contact with the second TiCN layer 17.

[0037] The Al2O3 layer 21 may have an average thickness of 1 to 15 μm. The average thickness of the Al2O3 layer 21 may be greater than the average thickness of the TiCNO layer 19. The Al2O3 layer 21 may be in contact with the TiCNO layer 19.

[0038] The coating layer 7 may be located on the entire surface 5 of the substrate 3, or may be located on only a portion of the surface 5. In other words, the coating layer 7 may be located on at least a portion of the surface 5 of the substrate 3.

[0039] The coating layer 7 may be formed by a chemical vapor deposition (CVD) method. In other words, the coating layer 7 may be a CVD film. Note that the coating layer 7 may also be a physical vapor deposition (PVD) film formed by a PVD method.

[0040] 1 shows a cutting insert as a non-limiting example of the coated tool 1. However, the form of the coated tool 1 is not limited to the cutting insert.

[0041] The coated tool 1 may have a first surface 23 (top surface), a second surface 25 (side surface) adjacent to the first surface 23, and a cutting edge 27 located at the intersection of the first surface 23 and the second surface 25.

[0042] The first surface 23 may be a rake face. The first surface 23 may be a rake face entirely, or only a portion of the first surface 23 may be a rake face. For example, a region of the first surface 23 along the cutting edge 27 may be a rake face.

[0043] The second surface 25 may be a flank. The second surface 25 may be a flank entirely, or only a portion thereof may be a flank. For example, a region of the second surface 25 along the cutting edge 27 may be a flank.

[0044] The cutting edge 27 may be located over the entire intersection of the first surface 23 and the second surface 25, or may be located over only a portion of this intersection. The cutting edge 27 can be used to cut a workpiece when a machined product is manufactured using the coated tool 1.

[0045] The coated tool 1 may have a through hole 29. The through hole 29 can be used to attach a screw, a clamp member, or the like when fixing the coated tool 1 to a holder. The through hole 29 may be formed from the first surface 23 to a surface (lower surface) located opposite the first surface 23, or may open in these surfaces. Note that there is no problem even if the through holes 29 are configured to open in opposing regions of the second surface 25.

[0046] The coated tool 1 may have a rectangular plate shape. However, the shape of the coated tool 1 is not limited to a rectangular plate shape. For example, the first surface 23 may have a triangular, pentagonal, hexagonal, or circular shape.

[0047] The coated tool 1 is not limited to a specific size. For example, the length of one side of the first surface 23 may be set to about 3 to 20 mm. Furthermore, the height from the first surface 23 to the surface (lower surface) located on the opposite side of the first surface 23 may be set to about 5 to 20 mm.

[0048] <Method for Manufacturing a Coated Tool> Next, a method for manufacturing a non-limiting one-sided coated tool according to the present disclosure will be described.

[0049] When manufacturing a coated tool, a substrate may be prepared first. An example of preparing a substrate made of a sintered alloy will be described below. First, a mixed powder may be obtained by adding metal powder, carbon powder, etc. to an inorganic powder such as a carbide, nitride, carbonitride, or oxide that can be fired to form a substrate, and mixing the powder. This mixed powder may then be molded into a desired tool shape by a known molding method, such as press molding, slip casting, extrusion molding, or cold isostatic pressing. The resulting molded body may then be fired in a vacuum or a non-oxidizing atmosphere to obtain a substrate made of a sintered alloy.

[0050] The surface of the obtained substrate may be subjected to honing (polishing). Honing may be performed by blasting, with an air pressure of 0.1 to 0.3 MPa and a slurry concentration of 5 to 15% by mass. In this case, cracks extending from the surface of the substrate toward the interior of the substrate are likely to form.

[0051] Next, a coating layer may be formed on the surface of the obtained substrate by a CVD method to obtain a coated tool. The coating layer may include, in order from the substrate, a Ti-based coating layer, a first TiCN layer (MT-TiCN layer), a second TiCN layer (HT-TiCN layer), a TiCNO layer, and an Al2O3 layer. The conditions for forming each layer will be described below.

[0052] When depositing a TiN layer as a Ti-based coating layer, a mixed gas containing 0.5 to 10 volume % titanium tetrachloride (TiCl4) gas, 10 to 60 volume % nitrogen (N2) gas, and the remainder hydrogen (H2) gas may be prepared as a reaction gas composition. This mixed gas may then be introduced into a chamber, and the deposition temperature may be set to 790 to 940°C and the pressure may be set to 8 to 50 kPa to deposit the TiN layer.

[0053] When forming a TiC layer as a Ti-based coating layer, a mixed gas containing 0.5 to 10 volume % titanium tetrachloride (TiCl4) gas, 5 to 30 volume % methane (CH4) gas, and the remainder hydrogen (H2) gas may be prepared as a reaction gas composition. This mixed gas may then be introduced into a chamber, and the film formation temperature may be set to 790 to 940°C and the pressure may be set to 8 to 50 kPa to form the TiC layer.

[0054] When at least three TiN layers and TiC layers are alternately stacked, the formation of the TiN layers and the formation of the TiC layers may be repeated alternately.

[0055] Here, the gas forming the Ti-based coating layer may be intentionally introduced into the cracks, so that part of the Ti-based coating layer is present in the cracks. For example, when the Ti-based coating layer is a single layer such as a TiN layer, setting the deposition temperature at a low temperature of 790 to 820°C will result in the Ti-based coating particles becoming finer and more easily penetrating into the cracks. Also, when the Ti-based coating layer has a layered structure in which at least three TiN layers and TiC layers are alternately stacked, the Ti-based coating particles become finer and more easily penetrating into the cracks. Note that when a Ti-based coating layer is simply formed, gas is less likely to penetrate into the cracks.

[0056] The first TiCN layer (MT-TiCN layer) may be formed as follows. First, a mixed gas containing 0.5 to 10 volume percent titanium tetrachloride (TiCl) gas, 5 to 60 volume percent nitrogen (N), 0.1 to 3 volume percent acetonitrile (CHCN), and the remainder hydrogen (H) gas may be prepared as the reaction gas composition. This mixed gas may then be introduced into a chamber, and the film formation temperature may be set to a relatively low temperature of 780 to 880°C, and the pressure may be set to 5 to 25 kPa, to form the first TiCN layer. If the content of acetonitrile (CHCN) gas is increased in the later stage of film formation compared to the early stage, the average crystal width of the titanium carbonitride columnar crystals constituting the first TiCN layer tends to be larger on the surface side than on the substrate side.

[0057] The second TiCN layer (HT-TiCN layer) may be formed as follows. First, a mixed gas containing 1 to 4 volume percent titanium tetrachloride (TiCl4) gas, 5 to 20 volume percent nitrogen (N2) gas, 0.1 to 10 volume percent methane (CH4) gas, and the remainder hydrogen (H2) gas may be prepared as the reaction gas composition. Then, this mixed gas may be introduced into a chamber, and the second TiCN layer may be formed at a film formation temperature of 900 to 990°C and a pressure of 5 to 40 kPa. The second TiCN layer may be formed at a higher temperature than the first TiCN layer.

[0058] The TiCNO layer may be formed as follows. First, a mixed gas containing 3 to 15 volume percent titanium tetrachloride (TiCl4) gas, 3 to 50 volume percent nitrogen (N2) gas, 0.5 to 15 volume percent methane (CH4) gas, 0.5 to 10 volume percent carbon monoxide (CO) gas, and the remainder hydrogen (H2) gas may be prepared as the reaction gas composition. This mixed gas may then be introduced into a chamber, and the film formation temperature may be set to 900 to 1010°C and the pressure may be set to 5 to 40 kPa to form the TiCNO layer.

[0059] The Al2O3 layer may be formed as follows. First, a mixed gas containing 3.5 to 15 volume percent aluminum trichloride (AlCl3) gas, 0.5 to 2.5 volume percent hydrogen chloride (HCl) gas, 0.5 to 5 volume percent carbon dioxide (CO2) gas, 0 to 1 volume percent hydrogen sulfide (HS) gas, and the remainder hydrogen (H2) gas may be prepared as the reaction gas composition. Then, this mixed gas may be introduced into a chamber, and the Al2O3 layer may be formed at a film formation temperature of 900 to 1010°C and a pressure of 5 to 20 kPa.

[0060] The above-described manufacturing method is merely an example of a method for manufacturing a coated tool, and it goes without saying that the coated tool is not limited to one manufactured by the above-described manufacturing method.

[0061] <Cutting Tool> Next, a non-limiting one-sided cutting tool 101 of the present disclosure will be described with reference to the drawings, taking as an example a case where the cutting tool 1 is provided with the above-described coated tool 1 .

[0062] The cutting tool 101 may include a holder 103 and a coated tool 1, as shown in a non-limiting example in Fig. 4. The holder 103 may extend from a first end 103a to a second end 103b and may have a pocket 105 on the side of the first end 103a. The coated tool 1 may be located in the pocket 105. When the cutting tool 101 includes the coated tool 1, stable cutting is possible due to the high wear resistance and chipping resistance of the coated tool 1.

[0063] The pocket 105 may be a portion to which the coated tool 1 is attached. The pocket 105 may be open at the outer peripheral surface of the holder 103 and at the end surface on the side of the first end 103a.

[0064] The coated tool 1 may be attached to the pocket 105 so that at least a part of the cutting edge 27 protrudes from the holder 103. Alternatively, the coated tool 1 may be attached to the pocket 105 by a screw 107. That is, the coated tool 1 may be attached to the pocket 105 by inserting the screw 107 into the through hole 29 of the coated tool 1 and inserting the tip of the screw 107 into a threaded hole formed in the pocket 105 to fix the screw 107 in the threaded hole. At this time, the lower surface of the coated tool 1 may be in direct contact with the pocket 105, or a sheet may be sandwiched between the coated tool 1 and the pocket 105.

[0065] Examples of materials for the holder 103 include steel and cast iron. When the material for the holder 103 is steel, the holder 103 has high toughness.

[0066] 4 illustrates a cutting tool 101 used for so-called turning. Examples of turning include inner diameter machining, outer diameter machining, and grooving. The cutting tool 101 (coated tool 1) is not limited to use for turning. For example, there is no problem in using the coated tool 1 for a cutting tool 101 used for milling.

[0067] The above has provided examples of the non-limiting one-sided coated tool 1 and cutting tool 101 of the present disclosure, but it goes without saying that the present disclosure is not limited to the above-mentioned embodiments and can be any as long as it does not deviate from the gist of the present disclosure.

[0068] For example, in the above non-limiting embodiment, the coated tool 1 is used as the cutting tool 101, but the coated tool 1 can be applied to other applications. Examples of other applications include wear-resistant parts such as sliding parts or dies, tools such as drilling tools and cutting tools, and impact-resistant parts.

[0069] The coated tool 1 and cutting tool 101 may also have the following configurations: (1) The coated tool is a coated tool including a substrate and a coating layer located on the surface of the substrate, the coating layer having a Ti-based coating layer that is in contact with the substrate, the substrate having a crack extending from the surface toward the inside of the substrate, and a part of the Ti-based coating layer being present in the crack. (2) In the coated tool of (1) above, the substrate may be a sintered alloy made of cemented carbide or cermet containing a hard phase and a binder phase. (3) In the coated tool of (1) above, the substrate may be made of a cemented carbide containing a hard phase and a binder phase, the hard phase may be made of tungsten carbide or tungsten carbide and at least one cubic crystal structure compound selected from carbides, nitrides, carbonates, oxynitrides of elements of Groups 4, 5, and 6 of the Periodic Table, and their mutual solid solutions, and the binder phase may be mainly composed of cobalt and / or nickel. (4) In the coated tool of (1) above, the substrate may be made of a cemented carbide containing a hard phase and a binder phase, and the amount of nitrogen contained in the cracks may be 2 mass% or more. (5) In the coated tool of (4) above, the amount of carbon contained in the cracks may be 2 to 30 mass%. (6) In the coated tool of any one of (1) to (5) above, the Ti-based coating layer may have a layered structure in which at least three TiN layers and TiC layers are alternately stacked, and the layer closest to the substrate in the layered structure may be the TiN layer. (7) In the coated tool of any one of (1) to (6) above, the coating layer may have, in order from the substrate, the Ti-based coating layer, a first TiCN layer, a second TiCN layer, a TiCNO layer, and an Al2O3 layer. (8) A cutting tool may include a holder extending from a first end to a second end and having a pocket on the side of the first end, and the coated tool of any one of (1) to (7) above located in the pocket.

[0070] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to the following examples.

[0071] [Samples No. 1 to 5] <Preparation of Coated Tools> First, a substrate was prepared. Specifically, a mixed powder was obtained by mixing 7 mass% of metallic cobalt powder having an average particle size of 1.2 μm, 2 mass% of titanium carbide powder having an average particle size of 2 μm, 1 mass% of niobium carbide powder having an average particle size of 2 μm, 3 mass% of tantalum carbide having an average particle size of 1.2 μm, 1 mass% of zirconium carbide having an average particle size of 1.2 μm, and the remainder, tungsten carbide powder having an average particle size of 1.5 μm. The average particle size of each powder was measured by a microtrack method.

[0072] The resulting mixed powder was then press-molded into a tool shape (CNMG120408) to obtain a molded body. The resulting molded body was then subjected to a binder removal treatment and then fired in a non-oxidizing atmosphere to obtain a substrate made of cemented carbide. The firing temperature was set to 1450°C, the firing time was set to 1 hour, and an argon atmosphere was used as the non-oxidizing atmosphere.

[0073] The composition of the obtained cemented carbide was measured by EDS. Specifically, cross-section observation was performed using an EDS attached to an SEM, with a magnification of 5,000 to 20,000 times, and the average value of measurements at five locations was measured. Five elements, namely, tungsten carbide, cobalt, titanium, carbon, and nitrogen, were selected for measurement by EDS.

[0074] The EDS measurement results showed that the obtained cemented carbide contained a hard phase and a binder phase. More specifically, the obtained cemented carbide contained a hard phase made of WC and a binder phase mainly composed of Co.

[0075] The surface of the obtained substrate was subjected to honing (polishing) by blasting, with an air pressure of 0.1 to 0.3 MPa and a slurry concentration of 5 to 15% by mass.

[0076] The cross section of the substrate after honing was observed with an SEM, and it was found that the substrate had a plurality of cracks.

[0077] Next, a coating layer was formed on the surface of the obtained substrate by CVD, to obtain the coated tool samples shown in Table 1. For the samples shown in Table 1, a Ti-based coating layer was first formed on the surface of the substrate, and then a first TiCN layer (MT-TiCN layer), a second TiCN layer (HT-TiCN layer), a TiCNO layer, and an Al2O3 layer were formed on this Ti-based coating layer in this order. The respective deposition conditions were as follows:

[0078] (Deposition conditions for Ti-based coating layer) When a single TiN layer was formed, a mixed gas containing 1 volume % titanium tetrachloride (TiCl4) gas, 38 volume % nitrogen (N2) gas, and the remainder hydrogen (H2) gas was prepared as the reaction gas composition. This mixed gas was then introduced into the chamber, and the deposition temperature, pressure, and deposition time were set as shown in Table 1.

[0079] When alternately stacking at least three TiN and TiC layers, a mixed gas for the TiC layer was first prepared. Specifically, the reactive gas composition for the TiC layer was prepared as a mixed gas consisting of 2 volume % titanium tetrachloride (TiCl4) gas, 10 volume % methane (CH4) gas, and the remainder hydrogen (H2) gas. The same mixed gas as used for forming a single TiN layer was used as the mixed gas for the TiN layer. These mixed gases were then alternately introduced into the chamber to obtain the composition shown in Table 1, and the film formation temperature, pressure, and film formation time were set as shown in Table 1.

[0080] In the compositions shown in Table 1, for example, "TiN-TiC-TiN" means that a TiN layer, a TiC layer, and a TiN layer are laminated in this order from the substrate. The film formation temperature and pressure are the same for the TiN layer and the TiC layer. The film formation time shown in Table 1 is the total of the film formation times for each layer. The film formation time for each layer is calculated using the formula: (film formation time) / (number of layers).

[0081] (Film formation conditions for the first TiCN layer (MT-TiCN layer)) First, a mixed gas consisting of 4 vol% titanium tetrachloride (TiCl4) gas, 23 vol% nitrogen (N2) gas, 0.4 vol% acetonitrile (CH3CN) gas, and the remainder hydrogen (H2) gas was prepared as the reaction gas composition. This mixed gas was then introduced into the chamber, and the film formation temperature was set to 850°C and the pressure to 9 kPa. The film formation time was set to 400 minutes.

[0082] (Film formation conditions for the second TiCN layer (HT-TiCN layer)) First, a mixed gas consisting of 4 volume % titanium tetrachloride (TiCl4) gas, 20 volume % nitrogen (N2) gas, 8 volume % methane (CH4) gas, and the remainder hydrogen (H2) gas was prepared as the reaction gas composition. This mixed gas was then introduced into the chamber, and the film formation temperature was set to 950°C and the pressure to 13 kPa. The film formation time was set to 80 minutes.

[0083] (Film formation conditions for TiCNO layer) First, a mixed gas containing 4 vol% titanium tetrachloride (TiCl4) gas, 20 vol% nitrogen (N2) gas, 8 vol% methane (CH4) gas, 2 vol% carbon monoxide (CO) gas, and the remainder hydrogen (H2) gas was prepared as the reaction gas composition. This mixed gas was then introduced into a chamber, and the film formation temperature and pressure were set to 950°C and 10 kPa, respectively. The film formation time was set to 30 minutes.

[0084] (Al2O3 Layer Deposition Conditions) First, a mixed gas containing 3.7 vol% aluminum trichloride (AlCl3) gas, 0.7 vol% hydrogen chloride (HCl) gas, 4.3 vol% carbon dioxide (CO2) gas, 0.3 vol% hydrogen sulfide (HS) gas, and the remainder hydrogen (H2) gas was prepared as the reaction gas composition. This mixed gas was then introduced into a chamber, and the deposition temperature and pressure were set to 950°C and 7.5 kPa, respectively. The deposition time was set to 380 minutes.

[0085] The presence of a portion of the Ti-based coating layer in the cracks of the obtained coated tools was confirmed according to the method exemplified above. Specifically, cross-sectional observation was performed using an EDS attached to an SEM. The measurement results are shown in the column "Presence of Ti-based coating layer in cracks" in Table 1. In this column, "Present" indicates that a portion of the Ti-based coating layer was present in the cracks, and "Absent" indicates that a portion of the Ti-based coating layer was not present in the cracks. In addition, composition analysis of the cracks was performed according to the method exemplified above. The measurement results are shown in the column "Crack composition" in Table 1.

[0086] <Evaluation> A cutting test was carried out on the obtained coated tool under the following conditions: Machining mode: turning Cutting speed: 300 m / min Feed: 0.3 mm / rev Depth of cut: 2 mm Workpiece: SCM435 φ200 round bar Machining condition: WET

[0087] The test results are shown in Table 1. In Table 1, "Cutting time (min) until chipping occurs" refers to the time until the cutting edge is chipped. Also, "Cutting time (min) until wear amount reaches 0.2 mm" refers to the time until the wear amount reaches 0.2 mm on the flank face of the cutting edge.

[0088]

[0089] Compared with samples Nos. 4 and 5, samples Nos. 1 to 3 exhibited higher wear resistance and chipping resistance.

[0090] DESCRIPTION OF SYMBOLS 1... Coated tool 3... Base body 5... Surface 7... Coating layer 9... Ti-based coating layer 11... Crack 13... First region 15... First TiCN layer 17... Second TiCN layer 19... TiCNO layer 21... Al2O3 layer 23... First surface (top surface) 25... Second surface (side surface) 27... Cutting edge 29... Through hole 101... Cutting tool 103... Holder 103a... First end 103b... Second end 105... Pocket 107... Screw

Claims

1. a substrate; a coating layer located on the surface of the substrate, the coating layer has a Ti-based coating layer, the Ti-based coating layer is in contact with the substrate, the substrate has cracks extending from the surface toward the interior of the substrate, A coated tool, wherein a portion of the Ti-based coating layer is present in the crack.

2. 2. The coated tool according to claim 1, wherein the substrate is a sintered alloy made of cemented carbide or cermet containing a hard phase and a binder phase.

3. the substrate is made of a cemented carbide containing a hard phase and a binder phase, the hard phase comprises tungsten carbide or tungsten carbide and at least one cubic crystal structure compound selected from the group consisting of carbides, nitrides, carbonates, oxynitrides of elements in Groups 4, 5 and 6 of the Periodic Table, and their mutual solid solutions; 2. The coated tool according to claim 1, wherein the binder phase is based on cobalt and / or nickel.

4. the substrate is made of a cemented carbide containing a hard phase and a binder phase, 2. The coated tool according to claim 1, wherein the amount of nitrogen contained in the cracks is 2 mass % or more.

5. 5. The coated tool according to claim 4, wherein the amount of carbon contained in the cracks is 2 to 30 mass %.

6. the Ti-based coating layer has a laminated structure in which at least three TiN layers and TiC layers are alternately laminated; 6. The coated tool according to claim 1, wherein the layer closest to the substrate in the laminated structure is the TiN layer.

7. The coating layer is made up of the Ti-based coating layer, the first TiCN layer, the second TiCN layer, the TiCNO layer, and an AlN layer, in that order from the substrate. ２ O ３ The coated tool according to any one of claims 1 to 5, comprising a layer.

8. a holder extending from a first end to a second end and having a pocket on the side of the first end; A cutting tool comprising: the coated tool according to any one of claims 1 to 5 located in the pocket.