Coated tool and cutting tool

Abstract

A coated tool according to a non-limiting aspect of the present disclosure comprises a substrate and a coating layer positioned on a surface of the substrate. The coating layer has a TiCNO layer and an Al2O3 layer. The Al2O3 layer is positioned in contact with the TiCNO layer at a position farther from the substrate than the TiCNO layer. The TiCNO layer has a plurality of composite protrusions including first protrusions that protrude toward the Al2O3 layer and second protrusions that protrude from the first protrusions in a direction that intersects the protrusion direction of the first protrusions. In a cross section intersecting the surface of the substrate, an average width A of the base portions of the first protrusions is 200 to 1200 nm, and an average length B of the first protrusions is 200 to 1000 nm. A cutting tool according to a non-limiting aspect of the present disclosure comprises a holder that extends from a first end toward a second end and has a pocket on the first end side, and the coated tool that is positioned in the pocket.

Description

Coated and cutting tools CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Japanese Patent Application No. 2022-177110, filed November 4, 2022, the entire disclosure of which is incorporated herein by reference.

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

[0003] Coated tools are known in which an Al2O3 layer or the like is laminated via a bonding film on the surface of a substrate such as cemented carbide, cermet, or ceramic. Coated tools in which a coating layer is formed on the surface of a substrate are used as cutting tools, etc.

[0004] With the recent trend toward high-efficiency cutting, cutting tools are increasingly being used for heavy interrupted cutting, where large impacts are applied to the cutting edge. Under such harsh cutting conditions, the coating layer is subjected to large impacts, making it prone to chipping and peeling. Therefore, the coating layer is required to have improved fracture resistance in addition to wear resistance.

[0005] As a technique for improving the chipping resistance of cutting tools, Japanese Patent No. 5303732 (Patent Document 1) discloses a method for sequentially depositing a bond film and an Al2O3 layer, and providing the bond film with dendrites extending toward the Al2O3 layer and branch-like protrusions connected to the dendrites, thereby increasing the adhesion between the bond film and the Al2O3 layer and suppressing peeling of the coating layer. Patent Document 1 discloses that the dendrites are Ti(CO) or Ti(CNO) and the branch-like protrusions are (TiAl)(CNO), and describes that after the dendrites are formed, the flow of the source gas is temporarily stopped, and the pressure and type of source gas are changed while maintaining the temperature to form branch-like protrusions with a composition different from that of the dendrites.

[0006] A non-limiting aspect of the coated tool disclosed herein is a coated tool including a substrate and a coating layer located on the surface of the substrate. The coating layer includes a TiCNO layer and an Al2O3 layer. The Al2O3 layer is located in contact with the TiCNO layer at a position farther from the substrate than the TiCNO layer. The TiCNO layer has a plurality of composite protrusions, each of which has a first protrusion protruding toward the Al2O3 layer and a second protrusion protruding from the first protrusion in a direction intersecting the protruding direction of the first protrusions. In a cross section perpendicular to the surface of the substrate, the average width A of the base of the primary protrusions is 200 to 1200 nm, and the average length B of the primary protrusions is 200 to 1000 nm.

[0007] A non-limiting aspect of the cutting tool of the present disclosure includes a holder extending from a first end to a second end and having a pocket on the first end side, and the coated tool described above positioned in the pocket.

[0008] FIG. 1 is a perspective view showing a non-limiting one-sided coated tool of the present disclosure. FIG. 2 is a cross-sectional view perpendicular to the surface of the substrate in the coated tool shown in FIG. 1. FIG. 3 is an enlarged view of the vicinity of the boundary between the TiCNO layer and the Al2O3 layer shown in FIG. 2. FIG. 4 is a schematic view illustrating primary projections A and B in the coated tool shown in FIG. 1. FIG. 5 is a schematic view illustrating secondary projections C and D in the coated tool shown in FIG. 1. FIG. 6 is a cross-sectional view showing a non-limiting one-sided coated tool of the present disclosure, and is a view corresponding to FIG. 3. FIG. 7 is a perspective view showing a non-limiting one-sided cutting tool of the present disclosure.

[0009] <Coated Tool> A non-limiting example 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 figures referred to below show only the main components necessary for explaining the embodiment in a simplified form. Therefore, the coated tool 1 may include optional components not shown in the figures referred to. Furthermore, the dimensions of the components in the figures do not faithfully represent the actual dimensions of the components or the dimensional ratios of each component. Note that although Figures 4 to 6 are cross-sectional views perpendicular to the surface of the substrate, the diagonal hatching indicating the cross section has been omitted to facilitate visual understanding.

[0010] 1 and 2, the coated tool 1 may include a substrate 3 and a coating layer 7 located on a surface 5 of the substrate 3. The coating layer 7 may include a TiCNO layer 9 (titanium carbonate nitride layer) and an AlO layer 11 (alumina layer). The AlO layer 11 may be located in contact with the TiCNO layer 9 at a position farther from the substrate 3 than the TiCNO layer 9.

[0011] 3, the TiCNO layer 9 may have a plurality of composite protrusions 13. Each of the plurality of composite protrusions 13 may have a first protrusion 15 protruding toward the Al2O3 layer 11 and a second protrusion 17 protruding from the first protrusion 15 in a direction intersecting the protruding direction of the first protrusion 15. In this case, due to the interlocking of the composite protrusions 13 with the Al2O3 layer 11, the TiCNO layer 9 and the Al2O3 layer 11 are less likely to peel off.

[0012] Here, as in a non-limiting example shown in FIGS. 3 and 4 , in a cross section perpendicular to the surface 5 of the base 3, A, which is the average width of the base 19 of the primary projections 15, may be 200 to 1200 nm, and B, which is the average length of the primary projections 15, may be 200 to 1000 nm.

[0013] The primary protrusions 15 having the above-described A and B have a relatively large overall size because both A and B are relatively large. The Al2O3 layer 11 located in contact with the TiCNO layer 9 where such primary protrusions 15 exist has a high texture coefficient Tc(006) and is likely to have a high degree of orientation. The effect of this Al2O3 layer 11 being likely to have a high degree of orientation, combined with the effect of the meshing between the composite protrusions 13 and the Al2O3 layer 11, tends to improve chipping resistance and wear resistance. Therefore, the coated tool 1 has high wear resistance and fracture resistance.

[0014] It should be noted that A may be 400 nm or more. A may be 1000 nm or less. B may be 400 nm or more. B may be 800 nm or less.

[0015] The width of the base 19 of the primary projection 15 may be the width of the portion that serves as the starting point of protrusion of the primary projection 15. The average width A of the base 19 of the primary projection 15 may be the average value of the widths of the bases 19 of 10 or more primary projections 15. Furthermore, the length of the primary projection 15 may be the length of a line segment connecting the central portion 19a of the width of the portion (base 19) that serves as the starting point of protrusion of the primary projection 15 to the tip 15a of the primary projection 15. The average length B of the primary projection 15 may be the average value of the lengths of 10 or more primary projections 15.

[0016] The base 19 of the first protrusion 15 may be the part of the first protrusion 15 that is located closest to the base 3. Furthermore, in a cross section perpendicular to the surface 5 of the base 3, the first protrusion 15 may be triangular. In this case, the base of the triangular first protrusion 15 may be the base 19 of the first protrusion 15. Furthermore, the tip 15a of the first protrusion 15 may be the part of the first protrusion 15 that is located farthest from the base 3. The tip 15a of the first protrusion 15 may be pointed.

[0017] Measurement of A and B may be performed by cross-sectional observation using an electron microscope. A cross section perpendicular to the surface 5 of the substrate 3 may be photographed using an electron microscope at a magnification of 15,000 times, and 10 or more composite protrusions 13 may be extracted from the obtained electron microscope photograph, and A and B may be measured. Examples of electron microscopes include a scanning electron microscope (SEM) and a transmission electron microscope (TEM). It is not necessary to measure A and B at multiple cross sections throughout the entire coated tool 1. A and B may be measured at one cross section at any location on the coated tool 1. The same applies to C and D, which will be described later.

[0018] The relationship between A and B may satisfy (A / B) > 1. In this case, A, which is the average width of the base 19 of the primary projections 15, becomes relatively large, making it easier to ensure the strength of the primary projections 15, which have a relatively large overall size. Therefore, the primary projections 15 are less likely to break.

[0019] At least one of the multiple composite protrusions 13 may have multiple second protrusions 17. In this case, the TiCNO layer 9 and the Al2O3 layer 11 are even less likely to peel off. All of the multiple composite protrusions 13 may have multiple second protrusions 17. When the composite protrusion 13 has multiple second protrusions 17, it means that multiple second protrusions 17 are located on one primary protrusion 15.

[0020] 3 and 5, in a cross section perpendicular to the surface 5 of the substrate 3, the average width C of the base 21 of the secondary projections 17 may be 20 to 150 nm, and the average length D of the secondary projections 17 may be 20 to 150 nm. The secondary projections 17 having such C and D are less likely to crack or break between them and the primary projections 15. Therefore, the TiCNO layer 9 and the AlO layer 11 are even less likely to peel off.

[0021] Note that C may be 40 nm or more. C may be 125 nm or less. D may be 40 nm or more. D may be 120 nm or less.

[0022] The width of the base 21 of the secondary projections 17 may be the width of the portion that serves as the protrusion starting point of the secondary projections 17. C, which is the average width of the base 21 of the secondary projections 17, may be the average value of the widths of the bases 21 of 10 or more secondary projections 17. Furthermore, the length of the secondary projections 17 may be the length of a line segment connecting the central portion 21a of the width of the portion (base 21) that serves as the protrusion starting point of the secondary projections 17 and the tip 17a of the secondary projection 17. D, which is the average length of the secondary projections 17, may be the average value of the lengths of 10 or more secondary projections 17. Measurement of C and D may be performed in the same manner as the measurement of A and B using an electron microscope described above.

[0023] The base 21 of the second protrusion 17 may be the part of the second protrusion 17 that is located closest to the first protrusion 15. Furthermore, in a cross section perpendicular to the surface 5 of the base 3, the second protrusion 17 may be triangular. In this case, the base of the triangular second protrusion 17 may be the base 21 of the second protrusion 17. Furthermore, the tip 17a of the second protrusion 17 may be the part of the second protrusion 17 that is located farthest from the first protrusion 15. The tip 17a of the second protrusion 17 may be pointed.

[0024] In a cross section perpendicular to the surface 5 of the base 3, the second projection 17 may have a first side 17b and a second side 17c that extend from two points where the first projection 15 and the second projection 17 meet toward a tip 17a of the second projection 17. As shown in a non-limiting example in FIG. 5 , the first side 17b and the second side 17c may be linear.

[0025] The first side 17b and the second side 17c do not have to be straight. For example, the first side 17b and the second side 17c may be curved, or may be a combination of straight and curved lines. In a non-limiting example shown in FIG. 6 , the first side 17b' and the second side 17c' are curved. When the second protrusion 17' is not a perfect triangle, as in the non-limiting example shown in FIG. 6 , the length of the line segment connecting the two points where the first protrusion 15 and the second protrusion 17' meet may be defined as the width of the base 21 of the second protrusion 17'. Furthermore, the length of the line segment connecting the center 21a of the width of the base 21 and the tip 17a of the second protrusion 17' may be defined as the length of the second protrusion 17'.

[0026] Furthermore, in a cross section such as that shown in Figure 6, when it is difficult to identify the boundary between the first protrusion 15 and the second protrusion 17', such as when the outer edges of the first protrusion 15 and the second protrusion 17' are both shown as curves and these curves are smoothly connected, the boundary between the first protrusion 15 and the second protrusion 17', i.e., the base 21 of the second protrusion 17', may be identified by the following procedure.

[0027] For example, if the outer edges of the first protrusion 15 and the second protrusion 17' are both curved, two curves are illustrated from the tip 17a of the second protrusion 17' toward the first protrusion 15 in a cross section such as that shown in Figure 6. At this time, a tangent line that touches both of these two curves is uniquely identified. The two points of contact between these two curves and the tangent line form the boundaries between the first protrusion 15 and the second protrusion 17'. In this case, the portion sandwiched between the two points of contact of the tangent lines corresponds to the base 21.

[0028] As described above, when it is difficult to identify the boundary between the first protrusion 15 and the second protrusion 17 in the cross section, it is sufficient to identify the tangent line that touches both of the two outer edges extending from the tip 17a of the second protrusion 17 toward the first protrusion 15. This makes it possible to identify the boundary between the first protrusion 15 and the second protrusion 17, and further to identify the base 21.

[0029] Note that when the outer edge of the first protrusion 15 in the cross section is curved, the width of the base 19 of the first protrusion 15 can also be evaluated using the same evaluation method as above. The base 19 of the first protrusion 15 can be identified by identifying the tangent lines that contact the target first protrusion 15 and two adjacent first protrusions 15 at their respective boundaries.

[0030] The relationship between C and D may satisfy (C / D) > 1. In this case, C, which is the average width of the base 21 of the secondary projections 17, becomes relatively large, so the secondary projections 17 are less likely to have an elongated shape and tend to have a stable shape. Therefore, cracks and breakage are less likely to occur between the primary projections 15 and the secondary projections 17.

[0031] The texture coefficient Tc(006) of the Al2O3 layer 11 may be 7.5 or more. In this case, chipping resistance and wear resistance are likely to be improved. The Al2O3 layer 11 may have an α-type crystal structure.

[0032] The texture coefficient Tc(006) may be measured by, for example, X-ray diffraction (XRD) analysis. Specifically, based on the peak of the Al2O3 layer 11 analyzed by XRD analysis, a value expressed by the following formula may be used as the texture coefficient Tc(hkl). The texture coefficient Tc(006) detected by measurement from the surface side of the Al2O3 layer 11 may be 7.5 or greater. Texture coefficient Tc(hkl)={I(hkl) / I0(hkl)} / [(1 / 9)×Σ{I(HKL) / I0(HKL)}], where (HKL) represents the (012), (104), (110), (006), (113), (024), (116), (214), and (146) crystal planes. I(HKL) and I(hkl) are the peak intensities of the peaks attributed to each crystal plane detected in the XRD analysis of the AlO layer 11. I(HKL) and I(hkl) are the standard diffraction intensities of each crystal plane listed in JCPDS Card No. 00-010-0173.

[0033] The TiCNO layer 9 may have protrusions 23 other than the composite protrusions 13, as shown in a non-limiting example in FIG. 3 . In this case, the composite protrusions 13 may account for 60% or more of the total protrusions. In this case, the composite protrusions 13 become the main protrusions. This makes it easier to obtain a coated tool 1 with high wear resistance and fracture resistance.

[0034] The upper limit of the ratio of the composite protrusions 13 may be, for example, 70%. Note that the upper limit of the ratio of the composite protrusions 13 is not limited to the exemplified value. For example, there is no problem even if the ratio of the composite protrusions 13 is 100%.

[0035] The ratio of the composite protrusions 13 is a value calculated from the formula: (number of composite protrusions / total number of protrusions) × 100. The total number of protrusions is the sum of the number of composite protrusions 13 and the number of other protrusions 23. The length of the other protrusions 23, measured in the same manner as the primary protrusions 15, may be 200 nm or more.

[0036] The total number of protrusions 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 15,000 times using an electron microscope, and the number of composite protrusions 13 and other protrusions 23 present within an area of ​​18.6 μm × 6 μm in the obtained electron microscope photograph may be measured. The total number of protrusions may be 5 to 20 per field of view in the electron microscope photograph. Furthermore, the total number of protrusions does not need to be measured on multiple cross sections throughout the entire coated tool 1. The total number of protrusions may be measured on one cross section at any location on the coated tool 1.

[0037] The primary projections 15 and the secondary projections 17 may contain titanium, carbon, nitrogen, and oxygen, or may have the same composition. In this case, cracks and breaks are less likely to occur between the primary projections 15 and the secondary projections 17, and the adhesion between the TiCNO layer 9 and the AlO layer 11 is stronger than when the primary projections 15 and the secondary projections 17 have different compositions.

[0038] Being homogeneous in composition may mean that the difference in the components is 5% or less. The difference in the components may be 3% or less, or may be 1% or less. For example, if the same gas is used when forming the primary projections 15 and the secondary projections 17, it is possible to obtain primary projections 15 and secondary projections 17 having the same composition.

[0039] The first protrusions 15 and the second protrusions 17 may have different compositions as needed. For example, if gases with different compositions are used when forming the first protrusions 15 and the second protrusions 17, it is possible to obtain first protrusions 15 and second protrusions 17 with different compositions.

[0040] The first protrusions 15 may protrude in a direction perpendicular to the surface 5 of the base 3, or may protrude in a direction inclined relative to the surface 5 of the base 3. The second protrusions 17 may protrude from a region of the first protrusions 15 excluding the tips 15a of the first protrusions 15, as in a non-limiting example shown in Figure 4. In this case, the effect of the first protrusions 15 can be easily obtained.

[0041] The coating layer 7 is not limited to a specific thickness. For example, the average thickness of the TiCNO layer 9 may be set to 200 to 2000 nm. In this case, the hardness of the TiCNO layer 9 is less likely to decrease, and the Al2O3 layer 11 is more likely to have an α-type crystal structure. The thickness of the TiCNO layer 9 is a value excluding the first protrusions 15 and the second protrusions 17. If the TiCNO layer 9 has other protrusions 23, the thickness of the TiCNO layer 9 is a value excluding the other protrusions 23.

[0042] The Al2O3 layer 11 may have an average thickness of 1 to 15 μm, which may be greater than the average thickness of the TiCNO layer 9.

[0043] 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 of each layer, and the average value may be calculated.

[0044] The TiCNO layer 9 may contain, for example, 30 to 70 atomic % titanium, 1 to 70 atomic % carbon, 1 to 35 atomic % nitrogen, and 3 to 20 atomic % oxygen. The TiCNO layer 9 may further contain aluminum at a rate of 10 atomic % or less, and may further contain components such as chlorine and chromium at a rate of 1 to 10 atomic %. The TiCNO layer 9 may also contain other trace components. The first protrusions 15 and the second protrusions 17 may have the same composition, or may have compositions within the above-mentioned ranges.

[0045] The elemental analysis may be performed by, for example, Energy Dispersive X-ray Spectroscopy (EDS), or by cross-sectional observation using an EDS attached to an electron microscope.

[0046] 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.

[0047] 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.

[0048] Examples of materials for the substrate 3 include hard alloys, ceramics, and metals. Examples of hard alloys include cemented carbides containing tungsten carbide (WC) and iron-group metals such as cobalt (Co) and nickel (Ni). Examples of other hard alloys include titanium carbonitride (TiCN) and Ti-based cermets containing iron-group metals. Examples of ceramics include silicon nitride (Si3N4), alumina (Al2O3), diamond, and cubic boron nitride (cBN). Examples of metals include carbon steel, high-speed steel, and alloy steel.

[0049] 1 shows a cutting insert as a non-limiting example of the coated tool 1. However, the coated tool 1 is not limited to the cutting insert.

[0050] The coated tool 1 may have a first surface 25 (top surface), a second surface 27 (side surface) adjacent to the first surface 25, and a cutting edge 29 located on at least a portion of the ridge between the first surface 25 and the second surface 27.

[0051] The first surface 25 may be a rake face. The entire first surface 25 may be a rake face, or only a part of the first surface 25 may be a rake face. For example, a region of the first surface 25 along the cutting edge 29 may be a rake face.

[0052] The second surface 27 may be a flank. The entire second surface 27 may be a flank, or only a part of the second surface 27 may be a flank. For example, a region of the second surface 27 along the cutting edge 29 may be a flank.

[0053] The cutting edge 29 may be located on a part of the ridgeline portion or may be located on the entire ridgeline portion. The cutting edge 29 can be used to cut a workpiece.

[0054] The coated tool 1 may have a through hole 31. The through hole 31 can be used to attach a fixing screw, a clamp member, or the like when holding the coated tool 1 in a holder. The through hole 31 may be formed from the first surface 25 to a surface (lower surface) located opposite the first surface 25, or may open in these surfaces. Note that there is no problem even if the through holes 31 are configured to open in opposing regions of the second surface 27.

[0055] 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 25 may have a triangular, pentagonal, hexagonal, or circular shape.

[0056] The coated tool 1 is not limited to a specific size. For example, the length of one side of the first surface 25 may be set to approximately 3 to 20 mm. Furthermore, the height from the first surface 25 to the surface (lower surface) located on the opposite side of the first surface 25 may be set to approximately 5 to 20 mm.

[0057] Next, a coated tool 1A according to another non-limiting aspect of the present disclosure will be described with reference to the drawings. The following mainly describes the differences between the coated tool 1A and the coated tool 1, and detailed description of the same configuration as the coated tool 1 may be omitted. Therefore, the description of the coated tool 1 may be used to understand the configuration of the coated tool 1A.

[0058] 7, the coating layer 7 of the coated tool 1A may include, in order from the substrate 3, a first TiCN layer 33, a second TiCN layer 35, a TiCNO layer 9, and an AlO layer 11. In this case, the life of the coated tool 1A is likely to be extended.

[0059] The first TiCN layer 33 may be a so-called MT (moderate temperature) TiCN layer. The first TiCN layer 33 may have an average thickness of 2 to 15 μm. In this case, the first TiCN layer 33 has high wear resistance and chipping resistance. The titanium carbonitride crystals contained in the first TiCN layer 33 may be columnar crystals that are elongated in the thickness direction of the coating layer 7.

[0060] The second TiCN layer 35 may be a so-called HT (high temperature)-TiCN layer, and may have an average thickness of 10 to 900 nm.

[0061] The carbon content ratio of the second TiCN layer 35 to the total content of carbon and nitrogen may be lower than the carbon content ratio of the first TiCN layer 33. In this case, the hardness of the first TiCN layer 33 is likely to be improved. As a result, the wear resistance and fracture resistance of the coated tool 1A are likely to be improved. The carbon content ratio means the ratio of the carbon content to the total content of carbon (C) and nitrogen (N) [C / (C+N)].

[0062] The carbon content of the first TiCN layer 33 may be 0.52 to 0.57, and the carbon content of the second TiCN layer 35 may be 0.42 to 0.51. In this case, the wear resistance and fracture resistance of the coated tool 1A are more likely to be improved. The first TiCN layer 33 may also have a carbon content of 15 to 29 atomic % and a nitrogen content of 22 to 35 atomic %. In this case, the wear resistance and fracture resistance of the coated tool 1A are more likely to be improved. The second TiCN layer 35 may have a carbon content of 13 to 24 atomic % and a nitrogen content of 23 to 35 atomic %. In this case, adhesion between the second TiCN layer 35 and the TiCNO layer 9 is high.

[0063] The first TiCN layer 33 may contain 45 to 60 atomic percent titanium, 15 to 29 atomic percent carbon, and 22 to 35 atomic percent nitrogen. In this case, the coated tool 1A has higher wear resistance and chipping resistance. The second TiCN layer 35 may contain 48 to 60 atomic percent titanium, 10 to 20 atomic percent carbon, and 15 to 25 atomic percent nitrogen. In this case, the second TiCN layer 35 is less likely to break, and adhesion between the second TiCN layer 35 and the TiCNO layer 9 is also high.

[0064] Oxygen may be present in both the first TiCN layer 33 and the second TiCN layer 35, and the amount of oxygen present in the second TiCN layer 35 may be greater than the amount of oxygen present in the first TiCN layer 33. For example, the first TiCN layer 33 may contain oxygen at a rate of 0.5 atomic % or less. The second TiCN layer 35 may contain oxygen at a rate of 1 to 10 atomic %.

[0065] The coating layer 7 may have other layers. For example, the coating layer 7 may have a surface layer. The surface layer may be located farthest from the substrate 3 in the coating layer 7. For example, the surface layer may be located on the Al2O3 layer 11. The material of the surface layer may be titanium nitride. That is, the surface layer may be a TiN layer.

[0066] The material of the surface layer is not limited to titanium nitride. The material of the surface layer may be, for example, titanium carbonitride, titanium carbonate nitride, or chromium nitride. The material of the surface layer may also be colored. In this case, it is easy to determine whether the cutting edge 29 has been used or not. The surface layer may have an average thickness of 0.1 to 3 μm.

[0067] The coating layer 7 may have an underlayer 37. The underlayer 37 may be located closest to the substrate 3 in the coating layer 7. For example, the underlayer 37 may be located between the substrate 3 and the first TiCN layer 33. When the substrate 3 contains components such as cobalt, carbon, and tungsten, the underlayer 37 may function as a layer that suppresses diffusion of these components into layers located above the underlayer 37. The underlayer 37 may also be a TiN layer. Note that the underlayer 37 may be formed as TiCN by the carbon component of the substrate 3 diffusing into TiN. The underlayer 37 may have an average thickness of 0.1 to 1 μm.

[0068] <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.

[0069] When manufacturing a coated tool, a substrate may be prepared first. An example of preparing a substrate made of a hard 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, casting, extrusion, 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 hard alloy. The surface of the resulting substrate may be polished or honed.

[0070] 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 TiN layer (underlayer), a first TiCN layer (MT-TiCN layer), a second TiCN layer (HT-TiCN layer), a TiCNO layer, an Al2O3 layer, and a TiN layer (surface layer). The conditions for forming each layer will be described below.

[0071] When a TiN layer is formed as an underlayer, the film may be formed as follows. First, a mixed gas containing 0.5 to 10 volume percent titanium tetrachloride (TiCl4) gas, 10 to 60 volume percent nitrogen (N2) 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 800 to 940°C and the pressure may be set to 8 to 50 kPa to form the TiN layer as an underlayer.

[0072] 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.

[0073] 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.

[0074] The TiCNO layer may be formed as follows. First, a mixed gas containing 3 to 15 volume percent titanium tetrachloride (TiCl) gas, 0 to 50 volume percent nitrogen (N), 0.2 to 2 volume percent methane (CH), 0.5 to 2 volume percent acetonitrile (CHCN), 0.5 to 10 volume percent carbon monoxide (CO), and the remainder hydrogen (H) may be prepared as the reaction gas composition. This mixed gas may then be introduced into a chamber, and the TiCNO layer may be formed at a deposition temperature of 900 to 990°C and a pressure of 5 to 40 kPa. Forming a TiCNO layer under these deposition conditions facilitates the formation of composite protrusions having primary and secondary protrusions with the above-described configuration. Furthermore, the AlO layer is likely to have a texture coefficient Tc(006) of 7.5 or higher.

[0075] 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. This mixed gas may then be introduced into a chamber, and the Al2O3 layer may be formed at a film formation temperature of 900 to 990°C and a pressure of 5 to 20 kPa.

[0076] When a TiN layer is to be formed as the surface layer, the film may be formed as follows. First, a mixed gas containing 0.1 to 10 volume percent titanium tetrachloride (TiCl4) gas, 10 to 60 volume percent nitrogen (N2) 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 film formation temperature may be set to 960 to 1100°C and the pressure may be set to 10 to 85 kPa to form the TiN layer as the surface layer.

[0077] In the obtained coated tool, at least the portion of the surface of the coating layer where the cutting edge is located may be polished. In this case, the cutting edge tends to be smooth. As a result, the coated tool is less susceptible to adhesion of the work material and is more likely to have high wear resistance and chipping resistance.

[0078] 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.

[0079] <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 .

[0080] 8 , the cutting tool 101 may include a holder 103 extending from a first end 103a to a second end 103b and having a pocket 105 on the side of the first end 103a, and a coated tool 1 positioned in the pocket 105. When the cutting tool 101 includes the coated tool 1, the coated tool 1 has high wear resistance and chipping resistance, enabling stable cutting.

[0081] 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.

[0082] The coated tool 1 may be attached to the pocket 105 so that the cutting edge 29 protrudes outward from the holder 103. Alternatively, the coated tool 1 may be attached to the pocket 105 by a fixing screw 107. That is, the fixing screw 107 may be inserted into the through hole 31 of the coated tool 1, and the tip of the fixing screw 107 may be inserted into a threaded hole formed in the pocket 105 to screw the threaded portions together, thereby attaching the coated tool 1 to the pocket 105. 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.

[0083] 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.

[0084] 8 illustrates a cutting tool 101 used for so-called turning. Examples of turning include inner diameter machining, outer diameter machining, and grooving. The application of the cutting tool 101 is not limited to turning. For example, there is no problem in using the cutting tool 101 for milling.

[0085] The above has provided examples of the non-limiting one-sided coated tools 1, 1A and cutting tool 101 of the present disclosure, but it goes without saying that the present disclosure is not limited to the above embodiments and can be any as long as it does not deviate from the gist of the present disclosure.

[0086] 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 also be used in other applications. Examples of other applications include wear-resistant parts such as sliding parts and dies, tools such as drilling tools and blades, and impact-resistant parts.

[0087] Furthermore, the cutting tool 101 described above includes the coated tool 1, but is not limited to this. For example, the cutting tool 101 may include a coated tool 1A instead of the coated tool 1.

[0088] The coated tool 1, 1A, and cutting tool 101 may also have the following configuration. (1) The coated tool includes a substrate and a coating layer located on the surface of the substrate, the coating layer having a TiCNO layer and an Al2O3 layer, the Al2O3 layer being located in contact with the TiCNO layer at a position farther from the substrate than the TiCNO layer, the TiCNO layer having a plurality of composite projections each having first projections projecting toward the Al2O3 layer and second projections projecting from the first projections in a direction intersecting the direction in which the first projections project, and in a cross section perpendicular to the surface of the substrate, A, which is the average width of the bases of the primary projections, is 200 to 1200 nm, and B, which is the average length of the primary projections, is 200 to 1000 nm. (2) The coated tool of (1) above may have a relationship between A and B satisfying (A / B)>1. (3) In the coated tool of (1) or (2) above, at least one of the multiple composite projections may have multiple secondary projections. (4) In any one of the coated tool of (1) to (3) above, the average width C of the bases of the secondary projections in the cross section may be 20 to 150 nm, and the average length D of the secondary projections may be 20 to 150 nm. (5) In the coated tool of (4) above, the relationship between C and D may satisfy (C / D) > 1. (6) In any one of the coated tool of (1) to (5) above, the Al2O3 layer may have a texture coefficient Tc(006) of 7.5 or more. (7) In any one of the coated tool of (1) to (6) above, the coating layer may have, in order from the substrate, a first TiCN layer, a second TiCN layer, the TiCNO layer, and the Al2O3 layer. (8) The cutting tool may include a holder extending from a first end toward a second end and having a pocket on the first end side, and a coated tool according to any one of (1) to (7) above, positioned in the pocket.

[0089] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to the following examples.

[0090] [Samples No. 1 to 6] <Preparation of Coated Tools> First, a substrate was prepared. Specifically, a mixed powder was obtained by mixing 6 mass% of metallic cobalt powder having an average particle size of 1.2 μm, 0.5 mass% of titanium carbide powder having an average particle size of 2 μm, 5 mass% of niobium carbide powder having an average particle size of 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 the Microtrac method.

[0091] Next, the resulting mixed powder was press-molded into a tool shape (CNMG120408) to obtain a molded body. The resulting molded body was then subjected to a binder removal process and fired in a non-oxidizing atmosphere to obtain a substrate made of cemented carbide. The firing temperature was set to 1450-1600°C, the firing time was set to 1 hour, and an argon atmosphere was used as the non-oxidizing atmosphere. The resulting substrate was then brushed, and the portion that would become the cutting edge was subjected to R-honing.

[0092] 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 TiN layer was first formed as an underlayer 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 TiN layer in this order. The respective film formation conditions were as follows:

[0093] (Film formation conditions for TiN layer (underlayer)) First, a mixed gas consisting of 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 a chamber, and the film formation temperature was set to 850°C and the pressure to 16 kPa. The film formation time was set to 180 minutes.

[0094] (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.

[0095] (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.

[0096] (Film formation conditions for TiCNO layer) As shown in Table 1.

[0097] (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.

[0098] The resulting coated tool was subjected to SEM observation of a cross section perpendicular to the surface of the substrate. Then, A, which is the average width of the bases of the primary projections, B, which is the average length of the primary projections, C, which is the average width of the bases of the secondary projections, and D, which is the average length of the secondary projections, were measured according to the method exemplified above. Measurements of A, B, C, and D were performed on one cross section on the rake face at a magnification of 15,000x, with 10 measurements each. Furthermore, (A / B) and (C / D) were calculated from the measured A, B, C, and D. Furthermore, the resulting coated tool was subjected to XRD analysis according to the method exemplified above, and the texture coefficient Tc(006) of the Al2O3 layer was measured.

[0099] The results of each measurement are shown in Table 1. (A / B) is shown in the "A / B" column of Table 1. (C / D) is shown in the "C / D" column of Table 1.

[0100] The ratio of composite protrusions was measured for the coated tools of Samples No. 1 to 4 according to the method exemplified above. As a result, composite protrusions accounted for 60 to 70% of the total protrusions. The total number of protrusions was measured in one cross section on the rake face. An SEM was used as the electron microscope. The magnification was 15,000 times. An area of ​​18.6 μm × 6 μm in the obtained SEM photograph was defined as one field of view. The total number of protrusions was 5 to 20 per field of view in the SEM photograph.

[0101] <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

[0102] 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.

[0103]

[0104] Samples Nos. 1 to 4 showed higher wear resistance and chipping resistance than samples Nos. 5 and 6.

[0105] DESCRIPTION OF SYMBOLS 1... Coated tool 3... Base 5... Surface 7... Coating layer 9... TiCNO layer 11... Al2O3 layer 13... Composite protrusion 15... First protrusion 15a... Tip 17... Second protrusion 17a... Tip 17b... First side 17c... Second side 19... Base of first protrusion 19a... Center 21... Base of second protrusion 21a... Center 23... Other protrusion 25... First surface (top surface) 27... Second surface (side surface) 29... Cutting edge 31... Through hole 33... First TiCN layer 35... Second TiCN layer 37... Base layer 101... Cutting tool 103... Holder 103a... First end 103b... Second end 105... Pocket 107... Fixing screw A: Average width of the base of the primary projections B: Average length of the primary projections C: Average width of the base of the secondary projections D: Average length of the secondary projections

Claims

1. A coated tool comprising a substrate and a coating layer disposed on a surface of the substrate, The coating layer is a TiCNO layer and an Al ２ O ３ and a layer, The Al ２ O ３ a layer is located in contact with the TiCNO layer at a position farther from the substrate than the TiCNO layer; The TiCNO layer is ２ O ３ a plurality of composite projections each having a first projection projecting toward a layer and a second projection projecting from the first projection in a direction intersecting with the projecting direction of the first projection; The coated tool, wherein, in a cross section perpendicular to the surface of the base, A which is an average width of the base of the primary projections is 200 to 1,200 nm, and B which is an average length of the primary projections is 200 to 1,000 nm.

2. The coated tool according to claim 1 , wherein a relationship between A and B satisfies (A / B)>1.

3. The coated tool according to claim 1 or 2, wherein at least one of the plurality of composite projections has a plurality of the second projections.

4. 3. The coated tool according to claim 1, wherein, in the cross section, an average width C of the base of the secondary projections is 20 to 150 nm, and an average length D of the secondary projections is 20 to 150 nm.

5. The coated tool according to claim 4 , wherein a relationship between C and D satisfies (C / D)>1.

6. The Al ２ O ３ 3. The coated tool according to claim 1, wherein the texture coefficient Tc(006) of the layer is 7.5 or more.

7. The coating layer is made up of a first TiCN layer, a second TiCN layer, the TiCNO layer, and the AlN layer, in that order from the substrate. ２ O ３ The coated tool according to claim 1 or 2, comprising a layer.

8. a holder extending from a first end to a second end and having a pocket on the first end side; A cutting tool comprising: the coated tool according to claim 1 or 2 located in the pocket.