Coating tool and cutting tool

Abstract

A coating tool according to a non-limiting aspect of the present disclosure comprises a substrate and a coating layer positioned on a first surface of the substrate. The coating layer has an AlTiCN film. The AlTiCN film has a plurality of first regions and a plurality of second regions. Each of the plurality of first regions has a plurality of first crystals, and each of the plurality of second regions has a plurality of second crystals. In a cross section orthogonal to the first surface, the plurality of first regions and the plurality of second regions are alternately positioned in a direction parallel to the first surface. The average value of cross-sectional areas of the plurality of first crystals is greater than the average value of cross-sectional areas of the plurality of second crystals.

Description

Covered tools and cutting tools Cross-reference of related applications

[0001] This application claims priority to Japanese Patent Application No. 2025-051319, filed on 26 March 2025, and the entire disclosure of the earlier application is incorporated herein by reference.

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

[0003] As a coated tool used for cutting tools and the like, for example, the coated tool (coating) described in Japanese Patent Publication No. 6238131 (Patent Document 1) is known. The coating described in Patent Document 1 is Ti 1-x Al x A first unit layer consisting of N and Ti 1-y Al y The material includes a multilayer structure in which a second unit layer made of N is alternately stacked. The first unit layer has an fcc type crystal structure, and x satisfies 0 < x < 0.65. The second unit layer has an hcp type crystal structure, and y satisfies 0.65 ≤ y < 1.

[0004] A one-sided coating tool, not limited to this disclosure, comprises a substrate having a first surface and a coating layer located on the first surface. The coating layer has an AlTiCN film. The AlTiCN film has a plurality of first regions, each having a plurality of first crystals, and a plurality of second regions, each having a plurality of second crystals. In a cross-section of the substrate perpendicular to the first surface, the direction parallel to the first surface is set as the first direction, and the direction perpendicular to the first surface is set as the second direction. The plurality of first regions and the plurality of second regions are alternately located in the first direction. The average value of the cross-sectional areas of the plurality of first crystals is greater than the average value of the cross-sectional areas of the plurality of second crystals.

[0005] This is a perspective view showing one aspect of a coated tool not limited to this disclosure. This is a cross-sectional view perpendicular to the surface (first surface) of the substrate in the coated tool shown in Figure 1. This is a side view showing one aspect of a cutting tool not limited to this disclosure.

[0006] <Coated Tool> Hereinafter, a non-limiting one aspect of the coated tool 1 of the present disclosure will be described in detail with reference to the drawings. However, for convenience of description, only main members necessary for describing the embodiment are simply shown in each drawing referred to below. Therefore, the coated tool 1 may include any constituent members not shown in the respective referenced drawings. In addition, the dimensions of members in each drawing do not faithfully represent the actual dimensions of constituent members, the dimensional ratio of each member, and the like. Note that FIG. 2 is a cross-sectional view orthogonal to the surface (first surface) of the base body, but for facilitating visual understanding, hatching with oblique lines indicating that it is a cross-section is omitted for the coating layer.

[0007] The coated tool 1 may include a base body 3 and a coating layer 7 located on the surface of the base body 3, as in the non-limiting example shown in FIG. 1 and FIG. 2. Specifically, the base body 3 may have a first surface 5 as one of the surfaces, and the coating layer 7 may be located on the first surface 5.

[0008] The coating layer 7 may include an AlTiCN film 9, as in the non-limiting example shown in FIG. 2. The composition of the AlTiCN film 9 is Al x Ti 1-x C y N 1-y (where 0 < x < 1, 0 ≦ y ≦ 1). That is, the AlTiCN film 9 is not limited to a composition containing Al (aluminum), Ti (titanium), C (carbon), and N (nitrogen), and may be a concept including a composition containing Al and Ti and not containing C or N. Therefore, the AlTiCN film 9 may be rephrased as an Al x Ti 1-x C y N 1-y film 9 (where 0 < x < 1, 0 ≦ y ≦ 1). Note that in the examples described later, y = 0, and the AlTiCN film 9 does not contain C. Such an AlTiCN film 9 may also be referred to as an AlTiN film 9. x and y may be measured by energy dispersive X-ray spectroscopy (EDS). The measurement may be performed using EDS attached to a scanning electron microscope (SEM).

[0009] Here, the AlTiCN film 9 may have a plurality of first regions 17 and a plurality of second regions 19. Each of the plurality of first regions 17 may have a plurality of first crystals 11. Each of the plurality of second regions 19 may have a plurality of second crystals 13. In the example shown in Figure 2, which is not limited, each of the plurality of first regions 17 is composed of a plurality of first crystals 11, and each of the plurality of second regions 19 is composed of a plurality of second crystals 13.

[0010] In a cross-section perpendicular to the first surface 5 of the substrate 3, the direction parallel to the first surface 5 of the substrate 3 is defined as the first direction Y1, and the direction perpendicular to the first surface 5 of the substrate 3 is defined as the second direction Y2. In this cross-section, the average value of the cross-sectional areas of the multiple first crystals 11 may be greater than the average value of the cross-sectional areas of the multiple second crystals 13.

[0011] In this case, the fracture energy that would otherwise destroy the AlTiCN film 9 due to cutting load or other factors is easily consumed by the second region 19, which contains multiple second crystals 13 that are relatively small in size. Specifically, because the second crystals 13 are relatively small, the size of defects in the crystal structure of the second region 19 is small, and the strength of the second region 19 tends to be high. Therefore, when cracks propagate in such a second region 19, a large amount of fracture energy is consumed, and widespread fracture of the AlTiCN film 9 is less likely to occur.

[0012] Furthermore, the first region 17, which contains multiple relatively large first crystals 11, prevents a decrease in the strength of the AlTiCN film 9. Specifically, because the first crystals 11 are relatively large, the thermal conductivity of the first region 17 is higher than that of the second region 19. Even if the temperature of the coating tool 1 rises during use, heat is easily dissipated from the AlTiCN film 9 by the first region 17, which has excellent thermal conductivity. Therefore, compared to the case where the AlTiCN film 9 is composed only of the second region 19, cracks caused by the difference in thermal expansion of these components are less likely to occur near the interface between the substrate 3 and the AlTiCN film 9.

[0013] In this way, the first region 17 makes it difficult for cracks caused by differences in thermal expansion between these components to occur near the interface between the substrate 3 and the AlTiCN film 9. In addition, even if cracks occur inside the AlTiCN film 9 due to cutting load or the like when using the coating tool 1, a large amount of fracture energy is consumed in the second region 19, and further crack propagation is easily reduced. As a result, widespread fracture of the AlTiCN film 9 is easily avoided.

[0014] Furthermore, in the above cross-section, the multiple first regions 17 and the multiple second regions 19 may be alternately positioned in the first direction Y1. In this case, the synergistic effect of the multiple first regions 17 and the multiple second regions 19 is easily obtained over a wide area of ​​the AlTiCN film 9. Therefore, it is less likely to lead to the complete destruction of the coating layer 7. Consequently, the coating tool 1 has a long lifespan.

[0015] In the above cross-section, the average value of the cross-sectional areas of the multiple first crystals 11 may be more than twice the average value of the cross-sectional areas of the multiple second crystals 13. When the difference between the average value of the cross-sectional areas of the multiple first crystals 11 and the average value of the cross-sectional areas of the multiple second crystals 13 is not small but more than twice, a synergistic effect is easily obtained between the consumption of fracture energy by the second region 19 and the reduction of crack generation caused by the difference in thermal expansion by the first region 17. In short, the division of roles between the first region 17 and the second region 19 becomes clear, and a synergistic effect from having these regions is easily obtained.

[0016] From the viewpoint of making the above-mentioned effects easier to obtain, in the above cross-section, the average value of the cross-sectional areas of the multiple first crystals 11 may be four times or more, or even six times or more, than the average value of the cross-sectional areas of the multiple second crystals 13. In addition, in the above cross-section, the average value of the cross-sectional areas of the multiple first crystals 11 may be eight times or less than the average value of the cross-sectional areas of the multiple second crystals 13.

[0017] In the above cross-section, the width W17 of the multiple first regions 17 in the first direction Y1 may be twice or more the average value of the width (size) W11a of the multiple first crystals 11 in the first direction Y1. In this case, multiple first crystals 11 are likely to exist in the first direction Y1 within each first region 17. Therefore, it is easier to avoid excessive load concentration on a particular crystal among the multiple first crystals 11. Consequently, defects in the multiple first crystals 11 are easily avoided, and the strength of the AlTiCN film 9 by the first region 17 can be stably improved.

[0018] Similarly, in the above cross-section, the width W19 of the multiple second regions 19 in the first direction Y1 may be twice or more the average value of the width (size) W13a of the multiple second crystals 13 in the first direction Y1. In this case, multiple second crystals 13 are likely to exist in the first direction Y1 within each second region 19. Therefore, the fracture energy described above is easily dispersed among the multiple second crystals 13, and the fracture of the second crystals 13 due to this fracture energy can be made sporadic. In this way, defects are less likely to occur continuously in the multiple second crystals 13 and can be made sporadic, so it is easier to avoid crack propagation from one of two adjacent first regions 17 to the other via this second region 19.

[0019] From the viewpoint of making the above-mentioned effects even easier to obtain, the following configuration may be used. In the above cross-section, the width W17 may be 3 times or more the average value of the width (size) W11a, and the width W19 may be 5 times or more the average value of the width (size) W13a. Alternatively, in the above cross-section, the width W17 may be 6 times or more the average value of the width (size) W11a, and the width W19 may be 9 times or more the average value of the width (size) W13a. Furthermore, in the above cross-section, the width W17 may be 8 times or less the average value of the width (size) W11a, and the width W19 may be 11 times or less the average value of the width (size) W13a.

[0020] In the above cross-section, with respect to the size in the first direction Y1, the average value of the multiple first crystals 11 may be twice or more the average value of the multiple second crystals 13. That is, in the first direction Y1, the average value of the size W11a of the multiple first crystals 11 may be twice or more the average value of the size W13a of the multiple second crystals 13.

[0021] Thus, when the difference between the average value of size W11a and the average value of size W13a is not small but more than twice, a synergistic effect is likely to be obtained between the consumption of fracture energy by the second region 19 and the improvement of the strength of the AlTiCN film 9 by the first region 17, similar to the case where the average value of the cross-sectional area of ​​multiple first crystals 11 is more than twice the average value of the cross-sectional area of ​​multiple second crystals 13.

[0022] Furthermore, in the above cross-section, with respect to the size in the second direction Y2, the average value of the multiple first crystals 11 may be twice or more the average value of the multiple second crystals 13. That is, in the second direction Y2, the average value of the size W11b of the multiple first crystals 11 may be twice or more the average value of the size W13b of the multiple second crystals 13.

[0023] Thus, when the difference between the average value of size W11b and the average value of size W13b is not small but more than twice, a synergistic effect is likely to be obtained between the consumption of fracture energy by the second region 19 and the improvement of the strength of the AlTiCN film 9 by the first region 17, similar to when the average value of the cross-sectional area of ​​multiple first crystals 11 is more than twice the average value of the cross-sectional area of ​​multiple second crystals 13.

[0024] The average size W11a of the multiple first crystals 11 may be 0.4 to 1.1 μm in the first direction Y1, and the average size W11b in the second direction Y2 may be 0.5 to 3.5 μm. Similarly, the average size W13a of the multiple second crystals 13 may be 0.05 to 0.4 μm in the first direction Y1, and the average size W13b in the second direction Y2 may be 0.2 to 1.5 μm. In these cases, the lifespan of the coating tool 1 tends to be longer. Note that the size W11a in the first direction Y1 is the minimum size of the first crystal 11 in the first direction Y1. Also, the size W11b in the second direction Y2 is the maximum size of the first crystal 11 in the second direction Y2. These points are the same for the second crystals 13. That is, the size W13a in the first direction Y1 is the minimum size of the second crystal 13 in the first direction Y1. Furthermore, the size W13b in the second direction Y2 is the maximum size of the second crystal 13 in the second direction Y2.

[0025] The sizes of the first crystal 11 and the second crystal 13 described above may be measured by grain boundary observation of the cross-section using electron backscatter diffraction, or by cross-sectional observation using a transmission electron microscope (TEM). This measurement may be performed in the following procedure. First, a band contrast diagram is obtained at a magnification of 10,000x using electron backscatter diffraction of an electron microscope, or a photograph is obtained at a magnification of 10,000x using a TEM, from a cross-section perpendicular to the first surface 5 of the substrate 3. Ten or more first crystals 11 and second crystals 13 are extracted from the obtained band contrast diagram or photograph. Then, the sizes of the first crystal 11 and second crystal 13 in the first direction Y1 and the second direction Y2 are measured, and the average value is calculated.

[0026] Examples of electron microscopes include SEM and the TEM mentioned above. It is not necessary to measure the size across multiple cross-sections of the entire coating tool 1. The size can be measured at any single cross-section of the coating tool 1.

[0027] The multiple first crystals 11 and the multiple second crystals 13 may be columnar in shape, extending from the substrate 3 toward the surface 15 of the coating layer 7, in other words, along the second direction Y2. In this case, the value calculated from the formula: (average value of size W11a in the first direction Y1) × (average value of size W11b in the second direction Y2) may be considered as the average value of the cross-sectional area of ​​the multiple first crystals 11. Alternatively, the value calculated from the formula: (average value of size W13a in the first direction Y1) × (average value of size W13b in the second direction Y2) may be considered as the average value of the cross-sectional area of ​​the multiple second crystals 13.

[0028] The average value of the cross-sectional area of ​​multiple first crystals 11 is 0.2 to 3.9 μm. 2 It may also be 0.7 to 2.4 μm 2 This may also be the case. The average value of the cross-sectional area of ​​the multiple second crystals 13 is 0.01 to 0.6 μm. 2 It may also be 0.06 to 0.6 μm 2 That's fine.

[0029] The multiple first crystals 11 may mainly contain crystals with an fcc type crystal structure (face-centered cubic structure). The multiple second crystals 13 may mainly contain crystals with an hcp type crystal structure (hexagonal close-packed structure). The crystal structure may be measured, for example, by X-ray diffraction (XRD) analysis.

[0030] Here, "primarily" means that when crystals with different crystal structures exist, the most numerous is the one with the most diverse crystal structure. For example, when multiple first crystals 11 contain crystals with an fcc-type crystal structure and crystals with an hcp-type crystal structure, the number of crystals with an fcc-type crystal structure may be greater than the number of crystals with an hcp-type crystal structure. Furthermore, in multiple first crystals 11, crystals with an fcc-type crystal structure may account for more than half. In particular, in multiple first crystals 11, crystals with an fcc-type crystal structure may account for 80% or more. Note that multiple first crystals 11 may be composed solely of crystals with an fcc-type crystal structure.

[0031] Similarly, for example, in a case where a plurality of said second crystals 13 include a crystal having an fcc crystal structure and a crystal having an hcp crystal structure, the number of crystals having an hcp crystal structure may be greater than the number of crystals having an fcc crystal structure. Furthermore, crystals having an hcp crystal structure may account for more than half of the plurality of said second crystals 13. In particular, crystals having an hcp crystal structure may account for 80% or more of the plurality of said second crystals 13. Note that the plurality of said second crystals 13 may be composed only of crystals having an hcp crystal structure.

[0032] Each of the plurality of said second regions 19 may be in contact with adjacent first regions 17. In this case, the entire coating layer 7 is less prone to fracture, and the service life of the coated tool 1 tends to be prolonged.

[0033] In the aforementioned cross-section, the size of the first regions 17 in the direction parallel to the first surface 5 of the base body 3 may be larger than that of the second regions 19. In other words, in the aforementioned cross-section, the width W17 of the plurality of first regions 17 in the first direction Y1 may be larger than the width W19 of the plurality of second regions 19 in the first direction Y1. That is, in the first direction Y1, the size W17 of the first region 17 may be larger than the size W19 of the second region 19. In this case, the entire coating layer 7 is less prone to fracture, and the service life of the coated tool 1 tends to be prolonged.

[0034] The size W17 of the first region 17 in the first direction Y1 may be not less than 5 μm and not more than 9 μm. Further, the size W19 of the second region 19 in the first direction Y1 may be not less than 2 μm and less than 5 μm. In these cases, the service life of the coated tool 1 tends to be prolonged.

[0035] The aforementioned sizes of the first region 17 and the second region 19 are average values. Further, the measurement of the aforementioned sizes may be performed by cross-sectional observation using an electron microscope. Said measurement may be carried out according to the following procedure. First, a cross-section orthogonal to the first surface 5 of the base body 3 is imaged at a magnification of 10,000 times using an electron microscope, to obtain an electron micrograph. In the obtained electron micrograph, no less than 5 first regions 17 and no less than 5 second regions 19 are respectively extracted. Then, the respective sizes of the first regions 17 and the second regions 19 in the first direction Y1 are measured, and the average value is calculated.

[0036] When the plurality of first crystals 11 and the plurality of second crystals 13 are each in a columnar shape extending from the base 3 side toward the surface 15 of the coating layer 7 as described above, in other words, along the second direction Y2, the average aspect ratio of the plurality of first crystals 11 may be larger than the average aspect ratio of the plurality of second crystals 13. The average aspect ratio is represented by (average value of size in the second direction Y2) / (average value of size in the first direction Y1).

[0037] When the average aspect ratio of the plurality of first crystals 11 is relatively large, the effect of improving the strength of the AlTiCN film 9 achieved by the first regions 17 is likely to be further enhanced. Further, when the average aspect ratio of the plurality of second crystals 13 is relatively small, the effect of consuming fracture energy achieved by the second regions 19 is likely to be further enhanced.

[0038] The plurality of first crystals 11 and the plurality of second crystals 13 may each have an average aspect ratio of 2 to 7.4.

[0039] When the average aspect ratio of the first crystals 11 and the second crystals 13 falls within the above numerical range, the service life of the coated tool 1 tends to be prolonged. When the average aspect ratio is 2 or more, the crystal may be evaluated as having a columnar morphology.

[0040] The AlTiCN film 9 may have a film hardness of 15 to 30 GPa. In this case, the coating layer 7 is less prone to chipping. Therefore, the service life of the coated tool 1 tends to be prolonged.

[0041] The film hardness of the first regions 17 may be larger than the film hardness of the second regions 19. In this case, the service life of the coated tool 1 tends to be prolonged. The film hardness of the first regions 17 may be not less than 25 GPa and not more than 30 GPa. The film hardness of the second regions 19 may be not less than 15 GPa and less than 25 GPa.

[0042] The film hardness may be a value measured in accordance with the evaluation method of ISO 14577. The film hardness may be measured by the following procedure. First, the AlTiCN film 9 is mirror-polished. If another film is present on the AlTiCN film 9, the surface 15 of the coating layer 7 is mirror-polished until the AlTiCN film 9 is exposed, and the film hardness of the AlTiCN film 9 is measured on the mirror surface of the exposed AlTiCN film 9.

[0043] For mirror polishing, a diamond paste with an average particle size of 1 to 3 μm manufactured by Tomei Diamond Co., Ltd. and olive oil manufactured by Yamakei Sangyo Co., Ltd. are used, adjusted to a paste concentration of 20 to 30% by mass. Furthermore, the mirror polishing is performed so that the mirror surface is parallel to the first surface 5 of the base body 3. Note that "parallel" does not mean strictly parallel, but rather that a tilt of approximately ±10° is acceptable.

[0044] The hardness of the film is measured by performing an indentation test on a mirror-finished surface using a nanoindenter. The nanoindenter used is the ENT-1100b / a ultra-micro indentation hardness tester manufactured by Elionix Co., Ltd. The indentation load is set to 10 mN. The indenter used is the triangular pyramidal indenter PA52071 manufactured by Elionix Co., Ltd.

[0045] The organization coefficient Tc(200) of the AlTiCN film 9 may be 1 or greater. In this case, the lifespan of the coating tool 1 tends to be longer. The organization coefficient Tc(200) of the AlTiCN film 9 may be 1.3 or greater. The organization coefficient Tc(200) of the AlTiCN film 9 may be 1.5 or less.

[0046] The organization coefficient Tc(200) may be measured, for example, by XRD analysis. Specifically, the orientation coefficient Tc(hkl) may be defined as the value expressed by the following formula, based on the peaks of the AlTiCN film 9 analyzed by XRD analysis. The organization coefficient Tc(200) detected by measurement from the surface side of the AlTiCN film 9 may be the value described above. Organization coefficient Tc(hkl) = {I(hkl) / I0(hkl)} / [(1 / 3) × Σ{I(hkl) / I0(hkl)}] Here, (hkl) is the crystal plane of (111), (200), and (110). I(hkl) and I(hkl) are the peak intensities of the peaks attributed to each crystal plane detected in the XRD analysis of the AlTiCN film 9. I0(HKL) and I0(hkl) are the standard diffraction intensities for each crystal plane as described on JCPDS card No. 00-037-1140.

[0047] The Ti / Al ratio of the AlTiCN film 9 may be 0.12 or higher. In this case, the lifespan of the coating tool 1 tends to be longer. The Ti / Al ratio is calculated using atomic ratios. The Ti / Al ratio may be measured, for example, by EDS. The measurement may be performed using an EDS attached to the SEM. The Ti / Al ratio of the AlTiCN film 9 may be 0.2 or lower.

[0048] The coating layer 7 is not limited to a specific thickness. For example, the AlTiCN film 9 may have an average thickness of 0.5 to 20 μm.

[0049] The average 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 locations on the film to be measured, and the average value may be calculated.

[0050] The coating layer 7 may have other films in addition to the AlTiCN film 9.

[0051] The coating layer 7 may be located on the entire first surface 5 of the substrate 3, or only on a part of it. Furthermore, if the substrate 3 has surfaces other than the first surface 5, there is no problem if the coating layer 7 is located on these other surfaces as well.

[0052] The coating layer 7 may be formed by chemical vapor deposition (CVD). In other words, the coating layer 7 may be a CVD film.

[0053] Examples of materials for the substrate 3 include hard alloys, ceramics, and metals. Examples of hard alloys include cemented carbides containing WC (tungsten carbide) and iron group metals such as Co (cobalt) or Ni (nickel). Examples of other hard alloys include Ti-based cermets containing TiCN (titanium carbonitride) and iron group metals. Examples of ceramics include Si3N4 (silicon nitride), Al2O3 (alumina), diamond, and cBN (cubic boron nitride). Examples of metals include carbon steel, high-speed steel, and alloy steel.

[0054] Figure 1 shows a cutting insert as an example of the coated tool 1, although this is not limited to a cutting insert.

[0055] The coating tool 1 may have a first surface 21 (top surface), a second surface 23 (side surface) adjacent to the first surface 21, and a cutting edge 25 located at the intersection of the first surface 21 and the second surface 23.

[0056] The first surface 21 may be a rake face. The entire first surface 21 may be a rake face, or only a part of it may be a rake face. For example, the area of ​​the first surface 21 along the cutting edge 25 may be a rake face.

[0057] The second surface 23 may be a relief surface. The entire second surface 23 may be a relief surface, or only a part of it may be a relief surface. For example, the region of the second surface 23 along the cutting edge 25 may be a relief surface.

[0058] The cutting edge 25 may be located across the entire intersection of the first surface 21 and the second surface 23, or it may be located only in a part of this intersection. The cutting edge 25 can be used to cut the workpiece when manufacturing a workpiece using the coated tool 1.

[0059] The coating tool 1 may have a through hole 27. The through hole 27 can be used to attach screws or clamp members when fixing the coating tool 1 to a holder. The through hole 27 may be formed from the first surface 21 to the surface opposite the first surface 21 (the bottom surface), or it may be open on these surfaces.

[0060] The coating tool 1 may be pentagonal in shape. However, the shape of the coating tool 1 is not limited to a pentagonal shape. For example, the first surface 21 may be triangular, square, hexagonal, or circular.

[0061] The coating tool 1 is not limited to a specific size. For example, the length of one side of the first surface 21 may be set to approximately 3 to 20 mm. Also, the height from the first surface 21 to the surface opposite to the first surface 21 (the bottom surface) may be set to approximately 5 to 20 mm.

[0062] <Method for Manufacturing a Covered Tool> Next, a method for manufacturing a covered tool, not limited to this disclosure, will be described.

[0063] 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 subjected to polishing or honing.

[0064] Next, a coating layer may be formed on the surface of the obtained substrate by CVD to obtain a coated tool.

[0065] AlTiCN films may be fabricated as follows. First, a mixed gas may be prepared as the reaction gas composition, consisting of 0.01 to 0.2 volume% TiCl4 (titanium tetrachloride) gas, 0.1 to 2 volume% AlCl3 (aluminum trichloride) gas, 1 to 20 volume% NH3 (ammonia) gas, and the remainder being H2 (hydrogen) gas. Of these gases, the group consisting of TiCl4 (titanium tetrachloride) gas, AlCl3 (aluminum trichloride) gas, and H2 (hydrogen) gas, and the NH3 (ammonia) gas may be separated and introduced into the chamber. The film fabrication temperature may be set to 700 to 900°C and the pressure to 1 to 10 kPa.

[0066] The flow rates may be set as follows: TiCl4 gas: 0.0015 to 0.005 L / min AlCl3 gas: 0.01 to 0.02 L / min NH3 gas: 0.05 to 0.2 L / min H2 gas: 1 to 5 L / min

[0067] Furthermore, an AlTiCN film may be fabricated by adjusting the flow rate ratio of TiCl4 gas to AlCl3 gas, AlCl3 / (TiCl4 + AlCl3), among the gas groups described above, to 0.8 to 0.85. When an AlTiCN film is fabricated under these conditions, the AlTiCN film tends to have the above-described structure. That is, the first crystal tends to be larger than the second crystal in the direction parallel to the first surface of the substrate and in the direction perpendicular to the first surface of the substrate. In other words, the average value of the cross-sectional areas of multiple first crystals tends to be larger than the average value of the cross-sectional areas of multiple second crystals. Also, the first and second regions tend to have the above-described structure. The average aspect ratio, film hardness, and Ti / Al ratio tend to fall within the above-described numerical range. It can be inferred that the reason for these results is that by adjusting the Ti / Al ratio to an Al composition that facilitates the formation of the hcp-AlN phase, the growth of microcrystals occurs in addition to the growth of coarse crystals.

[0068] Furthermore, when performing the polishing or honing processes described above on the substrate surface before forming the coating layer, a flat surface and an uneven surface may be formed on the surface (first surface). In this case, the first crystal (first region) is more likely to form on the flat surface, and the second crystal (second region) is more likely to form on the uneven surface. The flat surface and the uneven surface may be formed to be alternately located on the surface (first surface) of the substrate. This makes it easier for multiple first regions and multiple second regions to be alternately located in the first direction, even when cross-sections perpendicular to the first surface are taken from various directions.

[0069] A "flat surface" is defined as a surface with an arithmetic mean roughness (Ra) of 0.01 μm or more and less than 0.2 μm. An "uneven surface" is defined as a surface with an arithmetic mean roughness (Ra) of 0.2 μm or more and less than 1 μm. The arithmetic mean roughness (Ra) is measured in accordance with JIS B0601-2013. When forming flat and uneven surfaces by polishing, for example, polishing with coarse abrasive grains followed by polishing with fine abrasive grains may be performed. When forming flat and uneven surfaces by honing, for example, honing may be performed with media of different particle sizes mixed together. Specifically, honing may be performed with a mixture of a first media with an average particle size of 40 to 60 μm in a ratio of 40 to 60 mass% and a second media with an average particle size of 5 to 25 μm in a ratio of 40 to 60 mass%. The material of the first and second media may be alumina. The average particle size may be a value measured by laser diffraction.

[0070] During the film formation process described above, NH3 gas may be flowed periodically, for example, at intervals of 30 seconds to 3 minutes. When film formation is performed in this manner, the film formation period of each gas changes, and the first crystal tends to be larger than the second crystal. Also, the first and second regions tend to have the configuration described above.

[0071] Setting the film deposition temperature to 800°C or higher tends to result in the organization coefficient Tc(200) being the value described above.

[0072] In the resulting 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 become smoother. Therefore, the workpiece is less likely to weld to it, and the coated tool tends to have a longer lifespan.

[0073] 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.

[0074] <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 the above-described coated tool 1 is provided as an example.

[0075] The cutting tool 101 may include a holder 103 and a coating tool 1, as shown in the example (not limited to) in Figure 3. The holder 103 may extend from a first end 103a toward a second end 103b, and may have a pocket 105 on the side of the first end 103a. The coating tool 1 may be located in the pocket 105. When the cutting tool 101 includes a coating tool 1, stable cutting is possible because the lifespan of the coating tool 1 is long.

[0076] The pocket 105 may be the portion where the coating tool 1 is mounted. The pocket 105 may be open on the outer circumferential surface of the holder 103 and on the end surface on the side of the first end 103a. There may be only one pocket 105 or there may be multiple pockets 105. If the holder 103 has multiple pockets 105, the cutting tool 101 may be equipped with multiple coating tools 1, and one coating tool 1 may be located in each pocket 105.

[0077] The covering tool 1 may be mounted in the pocket 105 such that at least a portion of the cutting edge 25 protrudes from the holder 103. Alternatively, the covering tool 1 may be mounted in the pocket 105 by a screw 107. That is, the covering tool 1 may be mounted in the pocket 105 by inserting the screw 107 into the through hole 27 of the covering tool 1, and then inserting the tip of the screw 107 into a screw hole formed in the pocket 105 and fixing the screw 107 in the screw hole. 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.

[0078] Examples of materials for the holder 103 include steel and cast iron. When the holder 103 is made of steel, it has high toughness.

[0079] In the example shown in Figure 3, a cutting tool 101 used in so-called milling is illustrated. Examples of milling processes include milling cuts. Note that the cutting tool 101 (coated tool 1) is not limited to milling. For example, there is no problem in using the coated tool 1 as a cutting tool 101 used in turning.

[0080] The above exemplifies one aspect of the coating tool 1 and cutting tool 101 that are not limited to the present disclosure. However, it goes without saying that the present disclosure is not limited to the embodiments described above, and any such embodiments can be used as long as they do not deviate from the gist of the present disclosure.

[0081] For example, the coated tool 1 and the cutting tool 101 may have the following configurations: [1] The coated tool is a coated tool comprising a substrate having a first surface and a coating layer located on the first surface, wherein the coating layer has an AlTiCN film, and the AlTiCN film has a plurality of first regions each having a plurality of first crystals and a plurality of second regions each having a plurality of second crystals, and in a cross section perpendicular to the first surface of the substrate, the direction parallel to the first surface is set as the first direction and the direction perpendicular to the first surface is set as the second direction, the plurality of first regions and the plurality of second regions are alternately located in the first direction, and the average value of the cross-sectional area of ​​the plurality of first crystals is greater than the average value of the cross-sectional area of ​​the plurality of second crystals. [2] In the coated tool of [1] above, in the cross section, the average value of the cross-sectional area of ​​the plurality of first crystals may be twice or more than the average value of the cross-sectional area of ​​the plurality of second crystals. [3] In the coating tool of [1] or [2] above, in the cross-section, the width of the plurality of first regions in the first direction may be twice or more the average value of the widths of the plurality of first crystals in the first direction, and the width of the plurality of second regions in the first direction may be twice or more the average value of the widths of the plurality of second crystals in the first direction. [4] In any one of the coating tools of [1] to [3] above, in the cross-section, with respect to the size in the first direction, the average value of the plurality of first crystals may be twice or more the average value of the plurality of second crystals, and with respect to the size in the second direction, the average value of the plurality of first crystals may be twice or more the average value of the plurality of second crystals. [5] In any one of the coating tools of [1] to [4] above, the plurality of first crystals may mainly contain crystals with an fcc type crystal structure, and the plurality of second crystals may mainly contain crystals with an hcp type crystal structure. [6] In any one of the coating tools described in [1] to [5] above, the plurality of first crystals and the plurality of second crystals are columnar in shape extending along the second direction, and the average aspect ratio of the plurality of first crystals may be greater than the average aspect ratio of the plurality of second crystals. [7] In any one of the coating tools described in [1] to [6] above, the plurality of first crystals and the plurality of second crystals may each have an average aspect ratio of 2 to 7.4.[8] In any one of the coating tools described in [1] to [7] above, the AlTiCN film may have a film hardness of 15 to 30 GPa. [9] In any one of the coating tools described in [1] to [8] above, the organization coefficient Tc(200) of the AlTiCN film may be 1 or more.

[10] In any one of the coating tools described in [1] to [9] above, the Ti / Al ratio of the AlTiCN film may be 0.12 or more.

[11] The cutting tool may comprise a holder extending from a first end toward a second end and having a pocket on the side of the first end, and a coating tool described in any one of [1] to

[10] above located in the pocket.

[0082] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to the following examples.

[0083] [Sample No. 1-3] <Preparation of coated tools> First, the 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.

[0084] Next, the obtained mixed powder was press-molded into a tool shape (SNMU1406ANER-GM) 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°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.

[0085] Next, a coating layer was formed on the surface of the obtained substrate by CVD to obtain the coated tools shown in Table 1. The samples shown in Table 1 have an AlTiCN film formed on the surface of the substrate. The reaction gas composition of the mixed gas used for AlTiCN film formation is as described in Table 1. Additionally, a gas group consisting of TiCl4 gas, AlCl3 gas, and H2 gas, and NH3 gas were separated and introduced into the chamber. The film formation temperature was set as described in the "Temperature" column of Table 1. The pressure was set to 1 kPa. The film formation time was set to 10 to 30 minutes.

[0086] The flow rates were set as follows: Sample No. 1 TiCl4 gas: 0.0031 L / min AlCl3 gas: 0.014 L / min NH3 gas: 0.1 L / min H2 gas: 2.5 L / min Sample No. 2 TiCl4 gas: 0.004 L / min AlCl3 gas: 0.014 L / min NH3 gas: 0.1 L / min H2 gas: 2.5 L / min Sample No. 3 TiCl4 gas: 0.0035 L / min AlCl3 gas: 0.014 L / min NH3 gas: 0.1 L / min H2 gas: 2.5 L / min

[0087] The flow rate ratio of TiCl4 gas to AlCl3 gas, AlCl3 / (TiCl4 + AlCl3), is shown in the "AlCl3 / (TiCl4 + AlCl3)" column of Table 1.

[0088] In samples No. 1 and 3, honing was performed on the substrate before the coating layer was formed, with media of different particle sizes mixed together, so that flat surfaces and uneven surfaces were formed on the substrate surface (first surface). Specifically, honing was performed with a mixture of 50% by mass of a first media with an average particle size of 50 μm and 50% by mass of a second media with an average particle size of 15 μm. The material of the first and second media is alumina. The average particle size was measured by laser diffraction. Through this honing process, flat surfaces and uneven surfaces were formed alternately on the substrate surface (first surface). In addition, in samples No. 1 and 3, NH3 gas was flowed periodically at intervals of 30 seconds to 3 minutes during film formation.

[0089] <Evaluation> For the obtained coated tools, the composition of the AlTiCN film, the size of the first and second crystals, the average aspect ratio, film hardness, organization coefficient Tc(200), and Ti / Al ratio were measured. Cutting tests were also performed. The measurement conditions are shown below, and the results are shown in Table 1.

[0090] (Composition of AlTiCN film) The composition of the AlTiCN film was measured for the obtained coated tools. Specifically, Al x Ti 1-x C y N 1-y The x and y values ​​were measured using the EDS attached to the SEM. Five arbitrary points were measured using the EDS attached to the SEM, and the Al ratio and C ratio were determined from the average values ​​of Al, Ti, C, and N, respectively. The SEM used was the "JED-2300" manufactured by JEOL Ltd. This was the same for all other measurements. The measurement conditions were set as follows: Acceleration voltage: 20kV, Irradiation current level: 12

[0091] (Size of the first and second crystals) The average values ​​of the sizes of the first and second crystals in the first direction and the average values ​​of the sizes of the first and second crystals in the second direction were measured according to the electron backscatter diffraction procedure exemplified above. The measurement was performed on one cross-section of the scoop face, and the number of measurements was 50. An electron microscope (SEM) was used.

[0092] The average aspect ratio was defined as the value expressed by (average size in the second direction) / (average size in the first direction). Specifically, the average size of each size in the first and second crystals measured above was applied to the formula: (average size in the direction perpendicular to the first surface of the substrate) / (average size in the direction parallel to the first surface of the substrate) to calculate the average aspect ratio.

[0093] (Film Hardness) The film hardness of the AlTiCN film was measured in accordance with the evaluation method of ISO 14577. Specifically, it was measured according to the procedure exemplified above.

[0094] (Organization coefficient Tc(200)) The organization coefficient Tc(200) of the AlTiCN film was measured by XRD analysis. The measurement conditions were set as exemplified above.

[0095] (Ti / Al ratio) The Ti / Al ratio of the AlTiCN film was measured using an EDS attached to the SEM. The measurement conditions were the same as those for measuring the composition of the AlTiCN film.

[0096] (Cutting Test) The obtained coated tool was subjected to a cutting test under the following conditions: Machining method: Milling Cutting speed: 200 m / min Feed rate: 0.2 mm / rev Depth of cut: 2.0 mm Workpiece material: SCM440 Block material Machining condition: WET

[0097] The evaluation results are shown in the "Cutting Life (min)" column of Table 1. "Cutting Life (min)" represents the cutting time at which the damage width on the flank side of the cutting edge reaches 0.2 mm during machining.

[0098]

[0099] Samples No. 1 and 3 showed results indicating a long cutting life at the cutting edge.

[0100] In samples No. 1 and 3, the condition shown in Figure 2 was observed. Specifically, the AlTiCN films in samples No. 1 and 3 had multiple first regions and multiple second regions. The multiple first regions and multiple second regions in samples No. 1 and 3 were alternately located in a direction parallel to the first surface of the substrate (first direction). In addition, the second regions were in contact with adjacent first regions. On the other hand, in sample No. 2, only first regions were observed, and no second regions were present.

[0101] In samples No. 1 and 3, each of the multiple first regions was composed of multiple first crystals, and each of the multiple second regions was composed of multiple second crystals. Furthermore, the first and second crystals in samples No. 1 and 3 had an average aspect ratio of 2 or greater, and their crystal morphology was columnar. Therefore, the value calculated from the above formula: (average value of size W11a in the first direction Y1) × (average value of size W11b in the second direction Y2) was taken as the average value of the cross-sectional area of ​​the multiple first crystals. Similarly, the value calculated from the above formula: (average value of size W13a in the first direction Y1) × (average value of size W13b in the second direction Y2) was taken as the average value of the cross-sectional area of ​​the multiple second crystals. For sample No. 2, the value calculated in the same manner as for samples No. 1 and 3 was taken as the average value of the cross-sectional area of ​​the multiple first crystals. The calculated results are shown in Table 1 as "Cross-sectional area (μm)". 2 This will be shown in the ) section.

[0102] In sample No. 1, the average cross-sectional area of ​​multiple first crystals in the above cross-section was seven times greater than the average cross-sectional area of ​​multiple second crystals. In sample No. 3, the average cross-sectional area of ​​multiple first crystals in the above cross-section was five times greater than the average cross-sectional area of ​​multiple second crystals.

[0103] For samples No. 1 and 3, the sizes of the first and second regions in the direction parallel to the first surface of the substrate (first direction) were measured by cross-sectional observation using an electron microscope according to the procedure exemplified above. The measurement was performed on one cross-section of the scoop face, and the number of measurements was 5. A scanning electron microscope (SEM) was used.

[0104] The measurement results are as follows: Sample No. 1: First region: 3.71 μm, Second region: 2.37 μm. Sample No. 3: First region: 2.67 μm, Second region: 2.03 μm.

[0105] In sample No. 1, the width of the multiple first regions in the first direction in the above cross-section was seven times the average value of the widths of the multiple first crystals in the first direction, and the width of the multiple second regions in the first direction was ten times the average value of the widths of the multiple second crystals in the first direction. In sample No. 3, the width of the multiple first regions in the first direction in the above cross-section was four times the average value of the widths of the multiple first crystals in the first direction, and the width of the multiple second regions in the first direction was six times the average value of the widths of the multiple second crystals in the first direction.

[0106] For samples No. 1 to 3, the film hardness of the AlTiCN film was measured. Samples No. 1 and 3 exhibited both a high-hardness region (25 GPa or higher, 30 GPa or lower) and a low-hardness region (15 GPa or higher, less than 25 GPa). On the other hand, sample No. 2 did not exhibit a low-hardness region (15 GPa or higher, less than 25 GPa).

[0107] The crystal structures of the first and second crystals in samples No. 1 to 3 were measured by XRD analysis. The results showed that in samples No. 1 and 3, the first crystal had an fcc-type crystal structure, and the second crystal had an hcp-type crystal structure. That is, in samples No. 1 and 3, multiple first crystals were composed solely of crystals with an fcc-type crystal structure, and multiple second crystals were composed solely of crystals with an hcp-type crystal structure. On the other hand, sample No. 2 consisted only of first crystals, and no hcp-type crystal structure was observed. The measurement conditions for the XRD analysis were set as follows: Cu-Kα line: λ = 0.15418 nm, Output: 40 kV, 15 mA, 2θ range: 20° to 70°

[0108] 1...Coating tool 3...Substrate 5...First surface 7...Coating layer 9...AlTiCN film 11...First crystal 13...Second crystal 15...Surface 17...First region 19...Second region 21...First surface (top surface) 23...Second surface (side surface) 25...Cutting edge 27...Through hole 101...Cutting tool 103...Holder 103a...First end 103b...Second end 105...Pocket 107...Screw Y1...Direction parallel to the first surface of the substrate (first direction) Y2...Direction perpendicular to the first surface of the substrate (second direction) W17...Width of the first region in the first direction W19...Width of the second region in the first direction W11a...Width (size) of the first crystal in the first direction W13a...Width (size) of the second crystal in the first direction W11b: Size of the first crystal in the second direction. W13b: Size of the second crystal in the second direction.

Claims

1. A coating tool comprising a substrate having a first surface and a coating layer located on the first surface, wherein the coating layer has an AlTiCN film, the AlTiCN film has a plurality of first regions each having a plurality of first crystals, and a plurality of second regions each having a plurality of second crystals, in a cross section perpendicular to the first surface of the substrate, the direction parallel to the first surface is set as the first direction, and the direction perpendicular to the first surface is set as the second direction, the plurality of first regions and the plurality of second regions are alternately located in the first direction, and the average value of the cross-sectional areas of the plurality of first crystals is greater than the average value of the cross-sectional areas of the plurality of second crystals.

2. The coating tool according to claim 1, wherein, in the cross-section, the average value of the cross-sectional areas of the plurality of first crystals is twice or more than the average value of the cross-sectional areas of the plurality of second crystals.

3. The coating tool according to claim 1 or 2, wherein, in the cross-section, the width of the plurality of first regions in the first direction is at least twice the average value of the widths of the plurality of first crystals in the first direction, and the width of the plurality of second regions in the first direction is at least twice the average value of the widths of the plurality of second crystals in the first direction.

4. The coating tool according to any one of claims 1 to 3, wherein, in the cross-section, the average size of the plurality of first crystals is at least twice the average size of the plurality of second crystals with respect to the size in the first direction, and the average size of the plurality of first crystals is at least twice the average size of the plurality of second crystals with respect to the size in the second direction.

5. The coating tool according to any one of claims 1 to 4, wherein the plurality of first crystals mainly contain crystals having an fcc type crystal structure, and the plurality of second crystals mainly contain crystals having an hcp type crystal structure.

6. The coating tool according to any one of claims 1 to 5, wherein the plurality of first crystals and the plurality of second crystals are columnar in shape extending along the second direction, and the average aspect ratio of the plurality of first crystals is greater than the average aspect ratio of the plurality of second crystals.

7. The coating tool according to any one of claims 1 to 6, wherein each of the plurality of first crystals and the plurality of second crystals has an average aspect ratio of 2 to 7.

4.

8. The coating tool according to any one of claims 1 to 7, wherein the AlTiCN film has a film hardness of 15 to 30 GPa.

9. The coating tool according to any one of claims 1 to 8, wherein the organization coefficient Tc(200) of the AlTiCN film is 1 or more.

10. The coating tool according to any one of claims 1 to 9, wherein the Ti / Al ratio of the AlTiCN film is 0.12 or more.

11. The coating tool according to claim 1, wherein, in the cross-section, the width of the plurality of first regions in the first direction is greater than the width of the plurality of second regions in the first direction.

12. A cutting tool comprising: a holder extending from a first end toward a second end and having a pocket on the side of the first end; and a covering tool according to any one of claims 1 to 11, positioned in the pocket.

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