Covered tools and cutting tools

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

Cross-reference to related applications

[0001] This application claims the priority of Japanese Patent Application No. 2022-177110 filed on November 4, 2022, and the entire disclosure of the previous application is incorporated herein by reference for this purpose.

Technical Field

[0002] This disclosure relates to coated tools and cutting tools.

Background Art

[0003] Coated tools 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 ceramics are known. Coated tools having a coating layer formed on the surface of the substrate are used for cutting tools and the like. [[ID=2)]]

[0004] With the recent increase in the efficiency of cutting operations, cutting tools are being used more frequently in interrupted cutting operations where large impacts are applied to the cutting edges. Under such severe cutting conditions, large impacts are applied to the coating layer, and chipping and peeling of the coating layer are likely to occur. Therefore, in addition to wear resistance, improvement in chipping resistance is required for the coating layer.

[0005] In Patent No. 5303732 (Patent Document 1), as a technique for improving chipping resistance in cutting tools, a bonding film and an Al2O3 layer are formed in this order, and dendritic protrusions extending toward the Al2O3 layer side and branched protrusions continuous with the dendritic protrusions are provided on the bonding film, thereby increasing the adhesion between the bonding film and the Al2O3 layer and suppressing peeling of the coating layer. Patent Document 1 discloses that the dendritic protrusions are Ti(CO) or Ti(CNO), and the branched protrusions are (TiAl)(CNO). After forming the dendritic protrusions, it is described that once the flow of the source gas is stopped and the pressure and the type of the source gas are changed while maintaining the temperature, branched protrusions having a composition different from that of the dendritic protrusions are formed.

Summary of the Invention

[0006] A coating tool, not limited to this disclosure, is a coating tool comprising a substrate and a coating layer located on the surface of the substrate. The coating layer has a TiCNO layer and an Al2O3 layer. The Al2O3 layer is located in contact with the TiCNO layer at a position further from the substrate than the TiCNO layer. The TiCNO layer has a plurality of composite protrusions, each having a first protrusion projecting toward the Al2O3 layer and a second protrusion projecting from the first protrusion in a direction intersecting the direction of projection of the first protrusion. In a cross-section perpendicular to the surface of the substrate, A, the average width of the base of the first protrusions, is 200 to 1200 nm, and B, the average length of the first protrusions, is 200 to 1000 nm.

[0007] A cutting tool, not limited to this disclosure, comprises a holder extending from a first end to a second end and having a pocket on the first end side, and the covering tool located in the pocket. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing one aspect of a coating tool, not limited to this disclosure. [Figure 2] Figure 1 shows a cross-sectional view perpendicular to the surface of the substrate in the coating tool. [Figure 3] Figure 2 shows a magnified view of the area near the boundary between the TiCNO layer and the Al2O3 layer. [Figure 4] This is a schematic diagram illustrating A and B of the first projection in the coating tool shown in Figure 1. [Figure 5] This is a schematic diagram illustrating the second projections C and D in the coating tool shown in Figure 1. [Figure 6] This is a schematic diagram illustrating the second projections C and D in the coating tool shown in Figure 1. [Figure 7] This is a cross-sectional view showing one aspect of a coating tool, not limited to this disclosure, and corresponds to Figure 3. [Figure 8] This is a perspective view showing one aspect of a cutting tool, not limited to this disclosure. [Modes for carrying out the invention]

[0009] <Covered Tools> Hereinafter, a coating tool 1, not limited to this disclosure, will be described in detail with reference to the drawings. However, in the drawings referenced below, for the sake of clarity, only the main components necessary for describing the embodiment are shown in a simplified manner. Therefore, the coating tool 1 may include any components not shown in the drawings referenced below. Furthermore, the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components or the dimensional ratios of each component. Note that Figures 4 to 6 are also cross-sectional views perpendicular to the surface of the base body, but the hatching with diagonal lines indicating that they are cross-sections has been omitted to facilitate visual understanding.

[0010] The coating tool 1 may comprise a substrate 3 and a coating layer 7 located on the surface 5 of the substrate 3, as shown in the example, which is not limited to the examples shown in Figures 1 and 2. The coating layer 7 may have a TiCNO layer 9 (titanium carbonate nitride layer) and an Al2O3 layer 11 (alumina layer). The Al2O3 layer 11 may be located in contact with the TiCNO layer 9 at a position further from the substrate 3 than the TiCNO layer 9.

[0011] The TiCNO layer 9 may have a plurality of composite protrusions 13, as shown in the example (not limited to) in Figure 3. Each of the plurality of composite protrusions 13 may have a first protrusion 15 projecting toward the Al2O3 layer 11 and a second protrusion 17 projecting from the first protrusion 15 in a direction intersecting the direction of projection of the first protrusion 15. In this case, the interlocking of the composite protrusions 13 with the Al2O3 layer 11 makes it difficult for the TiCNO layer 9 and the Al2O3 layer 11 to peel off.

[0012] Here, as shown in the example not limited to Figures 3 and 4, in a cross section perpendicular to the surface 5 of the substrate 3, A, which is the average width of the base 19 of the first projection 15, may be 200 to 1200 nm, and B, which is the average length of the first projection 15, may be 200 to 1000 nm.

[0013] The first projection 15 having A and B as described above has 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 a first projection 15 exists tends to have a high degree of orientation due to a high organization coefficient Tc(006). The effect of the Al2O3 layer 11 tending to have a high degree of orientation, combined with the effect of the interlocking between the composite projection 13 and the Al2O3 layer 11, tends to improve chipping resistance and wear resistance. Therefore, the coated tool 1 has high wear resistance and chipping resistance.

[0014] Note that A may be 400 nm or greater. A may be 1000 nm or less. B may be 400 nm or greater. B may be 800 nm or less.

[0015] The width of the base 19 of the first projection 15 may be the width of the portion that serves as the starting point for the projection of the first projection 15. The average width A of the base 19 of the first projection 15 may be the average value of the widths of the base 19 of 10 or more first projections 15. The length of the first projection 15 may be the length of the line segment connecting the central part 19a of the width of the portion that serves as the starting point for the projection of the first projection 15 (base 19) and the tip 15a of the first projection 15. The average length B of the first projection 15 may be the average value of the lengths of 10 or more first projections 15.

[0016] The base 19 of the first projection 15 may be the part of the first projection 15 that is closest to the base 3. Also, in a cross-section perpendicular to the surface 5 of the base 3, the first projection 15 may be triangular in shape. In this case, the base of the triangular first projection 15 may be the base 19 of the first projection 15. Also, the tip 15a of the first projection 15 may be the part of the first projection 15 that is furthest from the base 3. The tip 15a of the first projection 15 may be pointed.

[0017] The measurements 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 at a magnification of 15,000 times using an electron microscope, and 10 or more composite protrusions 13 in the obtained electron micrograph may be extracted to measure A and B. Examples of the electron microscope may include a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Note that it is not necessary to measure A and B in a plurality of cross-sections over the entire coating tool 1. A and B may be measured in one cross-section at any location of the coating tool 1. These points are the same for C and D described later.

[0018] In the relationship between A and B, (A / B)>1 may be satisfied. In this case, since A, which is the average width of the base 19 of the first protrusion 15, becomes relatively large, it is easy to ensure the strength of the first protrusion 15 having a relatively large overall size. Therefore, the first protrusion 15 is less likely to break.

[0019] At least one of the plurality of composite protrusions 13 may have a plurality of second protrusions 17. In this case, the TiCNO layer 9 and the Al2O3 layer 11 are more difficult to peel off. Note that all of the plurality of composite protrusions 13 may have a plurality of second protrusions 17. That the composite protrusion 13 has a plurality of second protrusions 17 means that a plurality of second protrusions 17 are located on one first protrusion 15.

[0020] As shown in an exemplary but non-limiting example in FIGS. 3 and 5, in a cross-section perpendicular to the surface 5 of the substrate 3, C, which is the average width of the base 21 of the second protrusion 17, may be 20 to 150 nm, and D, which is the average length of the second protrusion 17, may be 20 to 150 nm. The second protrusion 17 having such C and D is less likely to cause cracks or fractures with the first protrusion 15. Therefore, the TiCNO layer 9 and the Al2O3 layer 11 are more difficult to peel off.

[0021] Incidentally, 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 second protrusion 17 may be the width of the portion that is the starting point of the protrusion of the second protrusion 17. C, which is the average width of the base 21 of the second protrusion 17, may be the average value of the widths of the bases 21 in 10 or more second protrusions 17. Further, the length of the second protrusion 17 may be the length of the line segment connecting the central portion 21a of the width of the portion (base 21) that is the starting point of the protrusion of the second protrusion 17 and the tip 17a of the second protrusion 17. D, which is the average length of the second protrusion 17, may be the average value of the lengths of 10 or more second protrusions 17. The measurement of C and D may be performed by the same method as the measurement of A and B using the electron microscope described above.

[0023] The base 21 of the second protrusion 17 may be the portion that is located closest to the first protrusion 15 in the second protrusion 17. Further, in a cross-section orthogonal to the surface 5 of the substrate 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. Further, the tip 17a of the second protrusion 17 may be the portion that is located farthest from the first protrusion 15 in the second protrusion 17. The tip 17a of the second protrusion 17 may be pointed.

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

[0025] Note that the first side 17b and the second side 17c do not have to be straight lines. For example, the first side 17b and the second side 17c may be curved, or they may be a combination of straight and curved lines. In the example shown in Figure 6, the first side 17b' and the second side 17c' are curved. If the second projection 17' is not a perfect triangle, as in the example shown in Figure 6, the length of the line segment connecting the two points where the first projection 15 and the second projection 17' touch may be used as the width of the base 21 of the second projection 17'. Alternatively, the length of the line segment connecting the central part 21a of the width of this base 21 and the tip 17a of the second projection 17' may be used as the length of the second projection 17'.

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

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

[0028] As described above, if it is difficult to determine the boundary between the first projection 15 and the second projection 17 in cross-section, a tangent line can be identified that touches both of the two outer edges extending from the tip 17a of the second projection 17 toward the first projection 15. This makes it possible to determine the boundary between the first projection 15 and the second projection 17, and furthermore, to identify the base 21.

[0029] Furthermore, when the outer edge of the first projection 15 in the cross-section is curved, the width of the base 19 of the first projection 15 can also be evaluated using the same evaluation method as described above. The base 19 of the first projection 15 can be identified by identifying the tangent lines that touch at the two boundaries between the target first projection 15 and two adjacent first projections 15.

[0030] In the relationship between C and D, (C / D) > 1 may be satisfied. In this case, since C, which is the average width of the base 21 of the second projection 17, becomes relatively larger, the second projection 17 is less likely to become elongated and is more likely to have a stable shape. Therefore, cracks and fractures are less likely to occur between the first projection 15 and the second projection 17.

[0031] The organization coefficient Tc(006) of the Al2O3 layer 11 may be 7.5 or higher. In this case, chipping resistance and wear resistance tend to improve. The Al2O3 layer 11 may also have an α-type crystal structure.

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

[0033] The TiCNO layer 9 may have other protrusions 23 different from the composite protrusions 13, as shown in the example (not limited to) in Figure 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. Therefore, the coated tool 1 tends to have high wear resistance and fracture resistance.

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

[0035] The ratio of composite protrusions 13 is calculated using 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 way as the first protrusion 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 15,000x using an electron microscope, and the number of composite protrusions 13 and other protrusions 23 present in an 18.6 μm × 6 μm area of ​​the resulting electron microscope image may be measured. The total number of protrusions may be 5 to 20 per field of view in the electron microscope image. Furthermore, the total number of protrusions does not need to be measured in multiple cross-sections across the entire coating tool 1. The total number of protrusions can be measured in a single cross-section at any point on the coating tool 1.

[0037] The first protrusion 15 and the second protrusion 17 may contain titanium, carbon, nitrogen, and oxygen, and their compositions may be the same. In this case, cracks and fractures are less likely to occur between the first protrusion 15 and the second protrusion 17, and the adhesion between the TiCNO layer 9 and the Al2O3 layer 11 is higher compared to the case where the compositions of the first protrusion 15 and the second protrusion 17 are different.

[0038] Having a homogeneous composition may mean that the difference between each component is 5% or less. The difference between components may be 3% or less, or even 1% or less. For example, if the same gas is used when depositing the first protrusion 15 and the second protrusion 17, it is possible to obtain the first protrusion 15 and the second protrusion 17 with a homogeneous composition.

[0039] Furthermore, the first projection 15 and the second projection 17 may have different compositions as needed. For example, by using gases with different compositions when forming the first projection 15 and the second projection 17, it is possible to obtain the first projection 15 and the second projection 17 with different compositions.

[0040] The first projection 15 may protrude in a direction perpendicular to the surface 5 of the substrate 3, or it may protrude in a direction inclined with respect to the surface 5 of the substrate 3. The second projection 17 may protrude from the region of the first projection 15 excluding the tip 15a, as shown in the example shown in Figure 4. In this case, the effect of the first projection 15 is easily obtained.

[0041] The coating layer 7 is not limited to a specific thickness. For example, the TiCNO layer 9 may have an average thickness of 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 form an α-type crystal structure. The thickness of the TiCNO layer 9 is the value excluding the first protrusion 15 and the second protrusion 17. If the TiCNO layer 9 has other protrusions 23, the thickness of the TiCNO layer 9 is the value excluding the other protrusions 23 as well.

[0042] The Al2O3 layer 11 may have an average thickness of 1 to 15 μm. The average thickness of the Al2O3 layer 11 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 arbitrary positions in each layer, and the average value may be calculated.

[0044] The TiCNO layer 9 may contain, for example, 30-70 atomic percent titanium, 1-70 atomic percent carbon, 1-35 atomic percent nitrogen, and 3-20 atomic percent oxygen. The TiCNO layer 9 may further contain aluminum in amounts of 10 atomic percent or less, and may further contain components such as chlorine and chromium in amounts of 1-10 atomic percent. The TiCNO layer 9 may also contain other trace components. The first projection 15 and the second projection 17 may have the same composition, or they may be within the compositional range described above.

[0045] Elemental analysis may also be performed using, for example, energy dispersive X-ray spectroscopy (EDS). Alternatively, elemental analysis may be performed by cross-sectional observation using EDS attached to an electron microscope.

[0046] The coating layer 7 may be located on the entire surface 5 of the substrate 3, or only on a portion of it. That is, 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 chemical vapor deposition (CVD). In other words, the coating layer 7 may be a CVD film. Furthermore, the coating layer 7 may be a PVD film formed by physical vapor deposition (PVD).

[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 Ti-based cermets containing titanium carbonitride (TiCN) and 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] Figure 1 shows a cutting insert as an example of the coated tool 1, although this is not limited to the coated tool 1.

[0050] The coating 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 ridges of the first surface 25 and the second surface 27.

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

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

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

[0054] The coating tool 1 may have a through hole 31. The through hole 31 can be used to attach a fixing screw or clamp member when holding the coating tool 1 in a holder. The through hole 31 may be formed from the first surface 25 to the surface opposite the first surface 25 (the bottom surface), or it may open on these surfaces. There is no problem if the through hole 31 is configured to open in mutually opposing regions on the second surface 27.

[0055] The coating tool 1 may be rectangular in shape. However, the shape of the coating tool 1 is not limited to a rectangular shape. For example, the first surface 25 may be triangular, pentagonal, hexagonal, or circular.

[0056] The coating 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. Also, the height from the first surface 25 to the surface opposite to the first surface 25 (the bottom surface) may be set to approximately 5 to 20 mm.

[0057] Next, a coating tool 1A, which is not limited to this disclosure, will be described with reference to the drawings. In the following, the differences between coating tool 1A and coating tool 1 will be mainly described, and detailed explanations of aspects that have the same configuration as coating tool 1 may be omitted. Therefore, the description of coating tool 1 may be used to understand the configuration of coating tool 1A.

[0058] In the coated tool 1A, the coating layer 7 may have, in order from the substrate 3, a first TiCN layer 33, a second TiCN layer 35, a TiCNO layer 9, and an Al2O3 layer 11, as shown in the example shown in Figure 7. In this case, the lifespan of the coated tool 1A tends to be longer.

[0059] The first TiCN layer 33 may be a so-called MT (moderate temperature)-TiCN layer. The average thickness of the first TiCN layer 33 may be set to 2 to 15 μm. In this case, the wear resistance and fracture resistance of the first TiCN layer 33 are high. The titanium carbonitride crystals contained in the first TiCN layer 33 may be elongated columnar crystals 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. The average thickness of the second TiCN layer 35 may be set to 10 to 900 nm.

[0061] The carbon content ratio in the second TiCN layer 35 relative to the total carbon and nitrogen content may be less than the carbon content ratio in the first TiCN layer 33. In this case, the hardness of the first TiCN layer 33 tends to improve. As a result, the wear resistance and chipping resistance of the coated tool 1A tend to improve. Note that the carbon content ratio refers to the ratio of the carbon content to the total carbon (C) and nitrogen (N) content [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 easily improved. The first TiCN layer 33 may also have a carbon content of 15 to 29 atomic percent and a nitrogen content of 22 to 35 atomic percent. In this case, the wear resistance and fracture resistance of the coated tool 1A are more easily improved. The second TiCN layer 35 may have a carbon content of 13 to 24 atomic percent and a nitrogen content of 23 to 35 atomic percent. In this case, the adhesion between the second TiCN layer 35 and the TiCNO layer 9 is high.

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

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

[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 furthest from the substrate 3 in the coating layer 7. For example, the surface layer may be located on top of 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 surface material is not limited to titanium nitride. For example, the surface material may be titanium carbonitride, titanium carbonate, or chromium nitride. The surface material may also be colored. In this case, it is easier to determine whether or not the cutting edge 29 is being used. The average thickness of the surface layer may be set to 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. The underlayer 37 may function as a layer that suppresses the diffusion of components such as cobalt, carbon, and tungsten into the layer located above the underlayer 37 when the substrate 3 contains these components. The underlayer 37 may also be a TiN layer. In addition, the underlayer 37 may be TiCN formed by the diffusion of the carbon component of the substrate 3 into TiN. The average thickness of the underlayer 37 may be set to 0.1 to 1 μm.

[0068] <Method for manufacturing covered tools> Next, a method for manufacturing a coating tool, not limited to this disclosure, will be described.

[0069] When manufacturing coated tools, a base material may be prepared first. An example of this process is described using a base material made of a hard alloy. First, an inorganic powder such as a carbide, nitride, carbonitride, or oxide, which can form a base material by firing, may be mixed with metal powder, carbon powder, etc., as appropriate to obtain a mixed powder. Next, this mixed powder may be molded into a predetermined tool shape using known molding methods such as press molding, casting, extrusion, or cold isostatic press molding. Then, the resulting molded body may be fired in a vacuum or a non-oxidizing atmosphere to obtain a base material made of a hard alloy. The surface of the obtained base material may be polished or honed.

[0070] Next, a coating layer may be deposited on the surface of the obtained substrate by CVD to obtain a coated tool. As an example, the deposition conditions for each layer will be explained in order, taking as an example the case in which the coating layer has, 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).

[0071] When depositing a TiN layer as a base layer, the following procedure may be used. First, a mixed gas may be prepared as the reaction gas composition, consisting of 0.5 to 10 volume% titanium tetrachloride (TiCl4) gas, 10 to 60 volume% nitrogen (N2) gas, and the remainder being hydrogen (H2) gas. Then, this mixed gas may be introduced into the chamber, the deposition temperature may be set to 800 to 940°C, and the pressure to 8 to 50 kPa, and the TiN layer as the base layer may be deposited.

[0072] The first TiCN layer (MT-TiCN layer) may be deposited as follows. First, a mixed gas may be prepared as the reaction gas composition, consisting of 0.5 to 10 volume% titanium tetrachloride (TiCl4) gas, 5 to 60 volume% nitrogen (N2) gas, 0.1 to 3 volume% acetonitrile (CH3CN) gas, and the remainder being hydrogen (H2) gas. Then, this mixed gas may be introduced into the chamber, the deposition 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 deposit the first TiCN layer. If the content ratio of acetonitrile (CH3CN) gas is increased in the later stages of deposition compared to the initial stages, 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 deposited as follows. First, a mixed gas may be prepared as the reaction gas composition, consisting of 1-4 volume% titanium tetrachloride (TiCl4) gas, 5-20 volume% nitrogen (N2) gas, 0.1-10 volume% methane (CH4) gas, and the remainder being hydrogen (H2) gas. Then, this mixed gas may be introduced into the chamber, and the deposition temperature may be set to 900-990°C and the pressure to 5-40 kPa to deposit the second TiCN layer. The second TiCN layer may be deposited at a higher temperature than the first TiCN layer.

[0074] The TiCNO layer may be deposited as follows. First, a mixed gas may be prepared as the reaction gas composition, consisting of 3 to 15 volume% titanium tetrachloride (TiCl4) gas, 0 to 50 volume% nitrogen (N2) gas, 0.2 to 2 volume% methane (CH4) gas, 0.5 to 2 volume% acetonitrile (CH3CN) gas, 0.5 to 10 volume% carbon monoxide (CO) gas, and the remainder being hydrogen (H2) gas. Then, this mixed gas may be introduced into a chamber, and the TiCNO layer may be deposited by setting the deposition temperature to 900 to 990°C and the pressure to 5 to 40 kPa. When a TiCNO layer is deposited under these deposition conditions, composite protrusions having the above-described first and second protrusions are easily formed. In addition, the organization coefficient Tc(006) of the Al2O3 layer tends to be 7.5 or higher.

[0075] The Al2O3 layer may be formed as follows. First, a mixed gas may be prepared as the reaction gas composition, consisting of 3.5 to 15 volume% aluminum trichloride (AlCl3) gas, 0.5 to 2.5 volume% hydrogen chloride (HCl) gas, 0.5 to 5 volume% carbon dioxide (CO2) gas, 0 to 1 volume% hydrogen sulfide (H2S) gas, and the remainder being hydrogen (H2) gas. Then, this mixed gas may be introduced into a chamber, the film deposition temperature may be set to 900 to 990°C and the pressure to 5 to 20 kPa, and the Al2O3 layer may be deposited.

[0076] When depositing a TiN layer as a surface layer, the following method may be used. First, a mixed gas can be prepared as the reaction gas composition, consisting of 0.1 to 10 volume% titanium tetrachloride (TiCl4) gas, 10 to 60 volume% nitrogen (N2) gas, and the remainder being hydrogen (H2) gas. Then, this mixed gas can be introduced into the chamber, the deposition temperature can be set to 960 to 1100°C, and the pressure to 10 to 85 kPa, and the TiN layer can be deposited as the surface layer.

[0077] In the resulting coated tool, polishing may be applied to at least the portion of the surface of the coating layer where the cutting edge is located. In this case, the cutting edge is more likely to become smooth. Therefore, the workpiece is less likely to weld to the tool, and the coated tool is more likely to have high wear resistance and fracture resistance.

[0078] It should be noted that the above manufacturing method is just one example of a method for manufacturing coated tools. Therefore, it goes without saying that coated tools are not limited to those manufactured by the above manufacturing method.

[0079] <Cutting tools> Next, a cutting tool 101, not limited to this disclosure, will be described with reference to the drawings, using the case in which it is equipped with the coated tool 1 described above as an example.

[0080] The cutting tool 101 may include, as shown in Figure 8 (not limited to this example), a holder 103 extending from a first end 103a toward a second end 103b and having a pocket 105 on the side of the first end 103a, and a coated tool 1 located in the pocket 105. When the cutting tool 101 includes a coated tool 1, stable cutting is possible due to the high wear resistance and fracture resistance of the coated tool 1.

[0081] The pocket 105 may be the portion into which the covering tool 1 is mounted. The pocket 105 may be open on the outer circumferential surface of the holder 103 and on the end face on the side of the first end 103a.

[0082] The covering tool 1 may be mounted in the pocket 105 such that the cutting edge 29 protrudes outward from the holder 103. Alternatively, the covering tool 1 may be mounted in the pocket 105 by a fixing screw 107. That is, the covering tool 1 may be mounted in the pocket 105 by inserting the fixing screw 107 into the through hole 31 of the covering tool 1 and inserting the tip of the fixing screw 107 into a screw hole formed in the pocket 105 and screwing the screw parts together. In this case, the lower surface of the covering tool 1 may be in direct contact with the pocket 105, or a sheet may be sandwiched between the covering tool 1 and the pocket 105.

[0083] Examples of materials for the holder 103 include steel and cast iron. When the holder 103 is made of steel, it has high toughness.

[0084] Figure 8 illustrates an example of a cutting tool 101 used in so-called turning operations. Examples of turning operations include internal diameter machining, external diameter machining, and grooving. However, the use of the cutting tool 101 is not limited to turning operations. For example, there is no problem in using the cutting tool 101 in milling operations.

[0085] The above examples illustrate one aspect of the coating tools 1, 1A and cutting tool 101, which are not limited to the embodiments described herein. However, it goes without saying that the present disclosure is not limited to the embodiments described above, and any other embodiments can be used as long as they do not deviate from the gist of the present disclosure.

[0086] For example, in the above-described, non-limiting embodiment, the case in which the coated tool 1 is used with the cutting tool 101 was explained as an example, but the coated tool 1 can be applied to other applications as well. Other applications include, for example, wear-resistant parts such as sliding parts and molds, tools such as drilling tools and cutting tools, and impact-resistant parts.

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

[0088] Furthermore, the coating tools 1, 1A and the cutting tool 101 may have the following configurations. (1) The coating tool comprises a substrate and a coating layer located on the surface of the substrate, wherein the coating layer has a TiCNO layer and an Al2O3 layer, the Al2O3 layer is located in contact with the TiCNO layer at a position further from the substrate than the TiCNO layer, the TiCNO layer has a plurality of composite protrusions having a first protrusion projecting toward the Al2O3 layer and a second protrusion projecting from the first protrusion in a direction intersecting the direction of projection of the first protrusion, and in a cross section perpendicular to the surface of the substrate, the average width A of the base of the first protrusion is 200 to 1200 nm, and the average length B of the first protrusion is 200 to 1000 nm. (2) The covering tool described in (1) above may satisfy (A / B) > 1 in the relationship between A and B. (3) The covering tool described in (1) or (2) above may have at least one of the plurality of composite protrusions having a plurality of the second protrusions. (4) In any one of the coating tools described in (1) to (3) above, the average width C of the base of the second projection in the cross-section may be 20 to 150 nm, and the average length D of the second projection may be 20 to 150 nm. (5) The covering tool described in (4) above may satisfy (C / D) > 1 in the relationship between C and D. (6) Any one of the coating tools described in (1) to (5) above may have an organization coefficient Tc(006) of the Al2O3 layer of 7.5 or more. (7) Any one of the coating tools described in (1) to (6) above may have a coating layer comprising, 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 comprise a holder extending from a first end toward a second end and having a pocket on the first end side, and one of the covering tools described in (1) to (7) above, located 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. [Examples]

[0090] [Samples No. 1-6] <Fabrication of coated tools> First, a substrate was prepared. Specifically, a mixed powder was obtained by mixing 6% by mass of metallic cobalt powder with an average particle size of 1.2 μm, 0.5% by mass of titanium carbide powder with an average particle size of 2 μm, 5% by mass of niobium carbide powder with an average particle size of 2 μm, and the remainder being tungsten carbide powder with an average particle size of 1.5 μm. The average particle size of each powder was measured using the microtrac method.

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

[0092] Next, a coating layer was deposited on the surface of the obtained substrate by CVD to obtain the coated tools shown in Table 1. For the samples shown in Table 1, a TiN layer was first deposited on the substrate surface as a base layer, and then a first TiCN layer (MT-TiCN layer), a second TiCN layer (HT-TiCN layer), a TiCNO layer, and an Al2O3 layer were deposited on top of this TiN layer in that order. The deposition conditions for each layer are as follows.

[0093] (Conditions for forming the TiN layer (underlayer)) First, a mixed gas was prepared as the reaction gas composition, consisting of 1 volume% titanium tetrachloride (TiCl4) gas, 38 volume% nitrogen (N2) gas, and the remainder being hydrogen (H2) gas. This mixed gas was then introduced into the chamber, and the film deposition temperature was set to 850°C and the pressure to 16 kPa. The film deposition time was set to 180 minutes.

[0094] (Conditions for forming the first TiCN layer (MT-TiCN layer)) First, a mixed gas was prepared as the reaction gas composition, consisting of 4% by volume of titanium tetrachloride (TiCl4) gas, 23% by volume of nitrogen (N2) gas, 0.4% by volume of acetonitrile (CH3CN) gas, and the remainder being hydrogen (H2) gas. This mixed gas was then introduced into the chamber, and the film deposition temperature was set to 850°C and the pressure to 9 kPa. The film deposition time was set to 400 minutes.

[0095] (Conditions for forming the second TiCN layer (HT-TiCN layer)) First, a mixed gas was prepared as the reaction gas composition, consisting of 4% by volume of titanium tetrachloride (TiCl4) gas, 20% by volume of nitrogen (N2) gas, 8% by volume of methane (CH4) gas, and the remainder being hydrogen (H2) gas. This mixed gas was then introduced into the chamber, and the film deposition temperature was set to 950°C and the pressure to 13 kPa. The film deposition time was set to 80 minutes.

[0096] (Conditions for depositing the TiCNO layer) As shown in Table 1.

[0097] (Conditions for depositing an Al2O3 layer) First, a mixed gas was prepared as the reaction gas composition, consisting of 3.7% by volume of aluminum trichloride (AlCl3), 0.7% by volume of hydrogen chloride (HCl), 4.3% by volume of carbon dioxide (CO2), 0.3% by volume of hydrogen sulfide (H2S), and the remainder being hydrogen (H2) gas. This mixed gas was then introduced into the chamber, and the film deposition temperature was set to 950°C and the pressure to 7.5 kPa. The film deposition time was set to 380 minutes.

[0098] The obtained coated tools were subjected to SEM observation of cross-sections perpendicular to the substrate surface. The average width A of the base of the first protrusion, the average length B of the first protrusion, the average width C of the base of the second protrusion, and the average length D of the second protrusion were measured according to the method exemplified above. Measurements of A, B, C, and D were performed on a single cross-section of the rake face at a magnification of 15,000x, with 10 measurements for each. (A / B) and (C / D) were calculated from the measured A, B, C, and D. Furthermore, the obtained coated tools were subjected to XRD analysis according to the method exemplified above, and the organization coefficient Tc(006) of the Al2O3 layer was measured.

[0099] The results for 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] For coated tools No. 1 to 4, the ratio of composite protrusions was measured according to the method exemplified above. As a result, composite protrusions accounted for 60-70% of the total protrusions. The total number of protrusions was measured in one cross-section of the rake face. An electron microscope (SEM) was used. The magnification was set to 15,000x. One field of view was defined as an 18.6 μm × 6 μm area of ​​the obtained SEM image. The total number of protrusions per field of view in the SEM image was 5-20.

[0101] <Rating> The obtained coated tools were subjected to cutting tests under the following conditions. Machining method: Turning Cutting speed: 300m / min Feed rate: 0.3mm / rev Cutting depth: 2mm Workpiece material: SCM435 φ200 round bar Processing condition: WET

[0102] The test results are shown in Table 1. In Table 1, "Cutting time until chipping occurs (minutes)" represents the time until the cutting edge is damaged. Also, "Cutting time until wear amount reaches 0.2 mm (minutes)" represents the time until the wear amount on the flank surface of the cutting edge reaches 0.2 mm.

[0103] [Table 1]

[0104] Samples No. 1-4 showed higher abrasion resistance and fracture resistance compared to samples No. 5-6. [Explanation of symbols]

[0105] 1. Covering Tools 3...Base 5...Surface 7...Covering layer 9...TiCNO layer 11...Al2O3 layer 13...Compound protrusion 15...1st protrusion 15a ··Tip 17...2nd protrusion 17a ··Tip 17b ··First side 17c··2nd side 19. Base of the first projection 19a · Central part 21. Base of the second projection 21a · Central part 23...Other protrusions 25...1st surface (top surface) 27...2nd side (side) 29...cutting edge 31... Through hole 33...1st TiCN layer 35...2nd TiCN layer 37...base layer 101...Cutting tools 103...Holder 103a...1st end 103b...2nd end 105... pockets 107... Fixing screws A...Average width of the base of the first projection B...Average length of the first projection C...Average width of the base of the second projection D...Average length of the second protrusion

Claims

1. A coating tool comprising a substrate and a coating layer located on the surface of the substrate, The aforementioned coating layer consists of a TiCNO layer and Al 2 O 3 It has layers, The Al 2 O 3 The layer is located in contact with the TiCNO layer at a position further from the substrate than the TiCNO layer, The TiCNO layer is made of the Al 2 O 3 It has a plurality of composite protrusions, each having a first protrusion that protrudes toward the layer and a second protrusion that protrudes from the first protrusion in a direction intersecting the direction of protrusion of the first protrusion. A coating tool wherein, in a cross section perpendicular to the surface of the substrate, A, which is the average width of the base of the first projection, is 400 to 1200 nm, and B, which is the average length of the first projection, is 400 to 1000 nm.

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

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

4. The coating tool according to claim 1 or 2, wherein in the cross-section, C, which is the average width of the base of the second projection, is 20 to 150 nm, and D, which is the average length of the second projection, is 20 to 150 nm.

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

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

7. The coating layer includes, in order from the substrate, a first TiCN layer, a second TiCN layer, the TiCNO layer, and the Al 2 O 3 layer. The coated tool according to claim 1 or 2

8. The TiCNO layer has other protrusions different from the composite protrusions, The coating tool according to claim 1 or 2, wherein the composite protrusions account for 60% or more of the total protrusions.

9. A holder extending from a first end toward a second end, with a pocket on the first end side, A cutting tool comprising a covering tool according to claim 1 or 2, located in the aforementioned pocket.

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