Cermet tool and cutting tool

Abstract

This cermet tool comprises a base body. The base body includes a hard phase containing Ti, a binding phase containing at least one of Ni and Co, and a solid solution phase containing Ti and W. The hard phase includes a plurality of hard phase particles. The plurality of hard phase particles satisfy the relationship of n2<n1 in the cross section of the base body. n1 indicates the number of a plurality of hard phase particles included in the cross section of the base body. n2 indicates the number of a plurality of hard phase particles included in the cross section of the base body and satisfying the relationship of Rij<D. D indicates the average particle diameter of the plurality of hard phase particles included in the cross section of the base body. Rij indicates the distance between an i-th hard phase particle and a j-th hard phase particle from among the plurality of hard phase particles included in the cross section of the base body. i and j are natural numbers satisfying i, j≤n1 and i<j or j<i.

Description

Cermet Tools and Cutting Tools

[0001] The present disclosure relates to cermet tools and cutting tools.

[0002] For example, Japanese Patent Application Laid-Open No. 2013-010997 discloses a cermet in which a hard phase containing a compound of at least one metal element selected from the metal elements of Groups 4, 5, and 6 of the periodic table and at least one element selected from carbon and nitrogen is bound by a binder phase mainly composed of an iron-group metal, and the hard phase can be classified into a first hard phase consisting only of titanium carbonitride, a second hard phase consisting of a composite carbonitride solid solution containing at least titanium and tungsten, and a third hard phase consisting of the same elements as the second hard phase and having a higher tungsten concentration than the second hard phase.

[0003] JP 2013-010997 A

[0004] A cermet tool according to one embodiment of the present disclosure includes a substrate. The substrate includes a hard phase containing Ti, a binder phase containing at least one of Ni and Co, and a solid solution phase containing Ti and W. The hard phase includes a plurality of hard phase particles. The plurality of hard phase particles satisfy the relationship n2<n1 in a cross section of the substrate. n1 indicates the number of the plurality of hard phase particles included in the cross section of the substrate. n2 indicates the number of R included in the cross section of the substrate. ｉｊ <D. D represents the average particle diameter of the hard phase particles contained in the cross section of the substrate. ｉｊ represents the distance between the ith hard phase particle and the jth hard phase particle among the plurality of hard phase particles contained in the cross section of the substrate, where i and j are natural numbers satisfying i, j≦n1 and i<j or j<i.

[0005] Fig. 1 is a perspective view showing an example of a cermet tool according to an embodiment. Fig. 2 is a side cross-sectional view showing an example of a cermet tool according to an embodiment. Fig. 3 is a schematic view showing a scanning electron microscope photograph of a cross section of a substrate according to an embodiment. Fig. 4 is a graph showing D and R of a plurality of hard phase particles according to an embodiment. ｉｊ5 is a front view showing an example of a cutting tool according to an embodiment. FIG. 6 is a scanning electron microscope photograph of a cross section of a substrate according to an example. FIG. 7 is an image of a plurality of hard phase particles extracted from a cross section of a substrate according to an example. FIG. 8 is a graph showing the R of a plurality of hard phase particles extracted from a cross section of a substrate according to an example. ｉｊ 9 is an image showing the analysis results of Fig. 9. Fig. 9 is a scanning electron microscope photograph of a cross section of a substrate according to a comparative example.

[0006] Hereinafter, modes for carrying out the cermet tool and cutting tool according to the present disclosure (hereinafter referred to as "embodiments") will be described in detail with reference to the drawings. The cermet tool and cutting tool according to the present disclosure are not limited to these embodiments. The embodiments can be appropriately combined as long as the processing content is not contradictory. In the following embodiments, the same components are denoted by the same reference numerals, and redundant explanations will be omitted.

[0007] In the following embodiments, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in a strict sense. In other words, the above expressions allow for deviations due to, for example, manufacturing precision or installation precision.

[0008] Conventional cermet tools have room for further improvement in terms of wear resistance and fracture resistance.

[0009] Therefore, there is a need for a technology that can overcome the above-mentioned problems and improve wear resistance and fracture resistance.

[0010] <Cermet Tool> Fig. 1 is a perspective view showing an example of a cermet tool according to an embodiment. Fig. 2 is a side cross-sectional view showing an example of a cermet tool 1 according to an embodiment.

[0011] 1 and 2 , the cermet tool 1 according to the embodiment includes a substrate 2. The cermet tool 1 according to the embodiment may include, in addition to the substrate 2, a coating layer 3 located on the surface of the substrate 2.

[0012] (Base 2) The base 2 has, for example, a hexahedral shape in which the upper and lower surfaces (surfaces intersecting with the Z axis shown in FIG. 1) are parallelograms.

[0013] One corner portion of the base body 2 functions as a cutting edge portion. The cutting edge portion includes a first surface (for example, an upper surface) and a second surface (for example, a side surface) connected to the first surface. In the embodiment, the first surface functions as a "rake surface" that scoops up chips generated by cutting, and the second surface functions as a "flank surface." A cutting edge is located on at least a portion of the ridge where the first surface and the second surface intersect, and the cermet tool 1 cuts the workpiece by bringing this cutting edge into contact with the workpiece.

[0014] A through-hole 21 that passes through the base 2 from top to bottom may be located in the center of the base 2. In this case, a screw 75 for attaching the cermet tool 1 to a holder 70 (described later) is inserted into the through-hole 21 (see FIG. 5).

[0015] The substrate 2 is made of cermet, which contains Ti (titanium), W (tungsten), and at least one of Co (cobalt) and Ni (nickel).

[0016] Fig. 3 is a diagram schematically showing a scanning electron microscope photograph of a cross section of a substrate 2 according to an embodiment. As shown in Fig. 3, the substrate 2 made of cermet includes a hard phase 5, a binder phase 6, and a solid solution phase 7. More specifically, in the substrate 2, the hard phase 5 and the solid solution phase 7 are bound by the binder phase 6. The hard phase 5 may be directly bound by the binder phase 6. Alternatively, the hard phase 5 may be indirectly bound by the binder phase 6 via the solid solution phase 7.

[0017] The hard phase 5 contains Ti. For example, the hard phase 5 contains at least one of Ti carbide, nitride, and carbonitride. For example, the hard phase 5 is mainly composed of TiCN. Here, "main component" means, for example, that the mass ratio of TiCN to the total mass of the components constituting the hard phase 5 is 55 mass% or more. The metal constituting the hard phase 5 contains, for example, Ti, W, and at least one metal of Group 4, Group 5, and Group 6 of the periodic table other than Ti and W. The content of Ti in the metal constituting the hard phase 5 is 80 mass% or more. The total content of W and at least one metal of Group 4, Group 5, and Group 6 of the periodic table other than Ti and W in the metal constituting the hard phase 5 is 1 mass% or more and 15 mass% or less. The hard phase 5 contains at least one of Co and Ni as the balance. Here, the total content of Ti, W, at least one of the metals of Groups 4, 5, and 6 of the periodic table other than Ti and W, Co, and Ni in the metals constituting the hard phase 5 is 100 mass%.

[0018] The binder phase 6 contains at least one of Ni and Co. For example, the binder phase 6 contains W and at least one of Ni and Co.

[0019] The solid solution phase 7 contains Ti and W. For example, the solid solution phase 7 is a solid solution containing at least one of a carbide, a nitride, and a carbonitride of Ti, W, and at least one metal of Groups 4, 5, and 6 of the periodic table other than Ti and W. For example, the metals constituting the solid solution phase 7 contain Ti, W, at least one metal of Groups 4, 5, and 6 of the periodic table other than Ti and W, and at least one of Ni and Co. The Ti content in the metals constituting the solid solution phase 7 is 30% by mass or more and 70% by mass or less. The total content of W and at least one metal of Groups 4, 5, and 6 of the periodic table other than Ti and W in the metals constituting the solid solution phase 7 is 70% by mass or more and 30% by mass or less. The total content of at least one of Ni and Co in the metals constituting the solid solution phase 7 is 0% by mass or more and 3% by mass or less. Here, the total content of Ti, W, at least one of metals in Groups 4, 5, and 6 of the periodic table other than Ti and W, and at least one of Ni and Co in the metals constituting the solid solution phase 7 is 100 mass%.

[0020] The hard phase 5 includes a plurality of hard phase particles. For example, the hard phase 5 is composed of a plurality of hard phase particles. The plurality of hard phase particles satisfy the relationship n2<n1 in the cross section of the substrate 2, where n1 indicates the number of the plurality of hard phase particles included in the cross section of the substrate 2, and n2 indicates the number of R included in the cross section of the substrate 2. ｉｊ <D represents the number of hard phase particles that satisfy the relationship, D represents the average particle diameter of the hard phase particles contained in the cross section of the substrate 2, and R ｉｊ indicates the distance between the ith hard phase particle and the jth hard phase particle among the plurality of hard phase particles contained in the cross section of the substrate 2, and i and j are natural numbers satisfying i, j ≦ n1 and i < j or j < i.

[0021] The cross section of the substrate 2 may be any cross section in which it is possible to confirm that the plurality of hard phase particles satisfy the relationship n2 < n1. The cross section of the substrate 2 is, for example, a backscattered electron image of the cross section taken by a scanning electron microscope (SEM). In the backscattered electron image, the hard phase 5 or the plurality of hard phase particles are observed to be darker than the solid solution phase 7. On the other hand, the binder phase 6 is observed to be whiter than the solid solution phase 7. In other words, the solid solution phase 7 is observed to be a grayish-white color between the color of the hard phase 5 or the plurality of hard phase particles and the color of the binder phase 6. The cross section of the substrate 2 may be, for example, a cross section having a size of 10 μm × 10 μm.

[0022] To identify each of the plurality of hard phase particles constituting the hard phase 5 in the cross section of the substrate 2, for example, an electron backscatter diffraction (EBSD) method using a scanning electron microscope can be used. Specifically, an electron beam is irradiated onto the cross section of the substrate 2 in the scanning electron microscope, and electrons reflected from the cross section of the substrate 2 are received by a fluorescent screen to obtain a Kikuchi pattern that reflects the crystal structure of each of the plurality of hard phase particles. Information regarding the crystal orientation of each of the plurality of hard phase particles can be obtained from this pattern, thereby making it possible to identify each of the plurality of hard phase particles.

[0023] Here, "the plurality of hard phase particles satisfy the relationship n2 < n1 in the cross section of the substrate 2" means, for example, that at least 95% of the plurality of hard phase particles satisfy the relationship n2 < n1 in the cross section of the substrate 2.

[0024] When calculating n1 and n2 for the plurality of hard phase particles in the cross section of the base 2, a binarization process may be applied to binarize a backscattered electron image of the cross section taken by a scanning electron microscope. The binarization process may be performed, for example, by coloring the image of the hard phase 5 in the backscattered electron image of the cross section taken by the scanning electron microscope black and coloring the images of the binder phase 6 and the solid solution phase 7 in white. When calculating n1 and n2 for the plurality of hard phase particles in the cross section of the base 2, an extraction process may be applied to extract a portion of the image of the hard phase 5 in the backscattered electron image of the cross section taken by the scanning electron microscope. The extraction process extracts a plurality of hard phase particles that constitute the hard phase 5 in the cross section taken by the scanning electron microscope, the particle diameters of which are equal to or greater than a certain threshold. For example, the extraction process may extract a plurality of hard phase particles having a particle diameter within 90% of the maximum particle diameter in the particle diameter distribution of the plurality of hard phase particles.

[0025] n1 indicates the number of hard phase particles contained in the cross section of the substrate 2. For example, n1 is the number of hard phase particles constituting the hard phase 5 in a backscattered electron image of the cross section taken by a scanning electron microscope. For example, n1 is the number of hard phase particles in a processed image obtained by applying at least one of the above-described binarization processing and extraction processing to the backscattered electron image of the cross section taken by a scanning electron microscope.

[0026] n2 is the R included in the cross section of the base 2 ｉｊ <D. D represents the average particle diameter of the hard phase particles contained in the cross section of the substrate 2. R ｉｊindicates the distance between the ith hard phase particle and the jth hard phase particle among the plurality of hard phase particles contained in the cross section of the substrate 2. i and j are natural numbers that satisfy i, j ≦ n1 and i < j or j < i. Here, the natural numbers that satisfy i, j ≦ n1 and i < j or j < i mean either natural numbers that satisfy i, j ≦ n1 and i < j or natural numbers that satisfy i, j ≦ n1 and j < i. n2 indicates the number of combinations of multiple hard phase particles that satisfy the requirement that the distance between the multiple hard phase particles is smaller than the average particle size of the multiple hard phase particles. Here and hereinafter, the "combination" does not take into account the order.

[0027] FIG. 4 shows the D and R values ​​for multiple hard phase particles according to an embodiment. ｉｊ 1 is a diagram illustrating the calculation of D and R for a plurality of hard phase particles according to an embodiment. ｉｊ When calculating, for example, a processed image obtained by applying at least one of the above-described binarization processing and extraction processing to a backscattered electron image of a cross section taken by a scanning electron microscope may be used.

[0028] Regarding D, first, as shown in Fig. 4, the particle diameter Di of the ith hard phase particle 5i contained in the cross section of the base 2 is calculated. Specifically, as shown in Fig. 4, the particle diameter Di of the ith hard phase particle 5i contained in the cross section of the base 2 is calculated as the diameter of the largest circumscribed circle centered at the center Ci of the ith hard phase particle 5i. Next, for n1 hard phase particles contained in the cross section of the base 2, the average particle diameter Di of the ith hard phase particle 5i contained in the cross section of the base 2 is calculated. In other words, the sum of the particle diameters Di of the ith hard phase particles 5i for i = 1 to n1 / n1 is calculated. The value calculated in this way is used as the average particle diameter D of the multiple hard phase particles contained in the cross section of the base 2.

[0029] R ｉｊ As shown in FIG. 4, the distance R between the i-th hard phase particle 5i and the j-th hard phase particle 5j included in the cross section of the substrate 2 is ｉｊ Specifically, as shown in FIG. 4, the distance R between the ith hard phase particle 5i and the jth hard phase particle 5j included in the cross section of the substrate 2 is calculated. ｉｊis calculated as the shortest distance between the i-th hard phase particle 5i and the j-th hard phase particle 5j. That is, the distance R ｉｊ is the distance between the point on the ith hard phase particle 5i that is closest to the jth hard phase particle 5j and the point on the jth hard phase particle 5j that is closest to the ith hard phase particle 5i.

[0030] A plurality of hard phase particles contained in the cross section of the substrate 2 are R ｉｊ <D. It is determined whether the j-th hard phase particle 5j satisfies the relationship R ｉｊ <D, the combination of the i-th hard phase particle 5i and the j-th hard phase particle 5j satisfies the relationship R ｉｊ On the other hand, it is determined that the j-th hard phase particle 5j satisfies the relationship of R ｉｊ <D, the combination of the i-th hard phase particle 5i and the j-th hard phase particle 5j does not satisfy the relationship R ｉｊ <D. ｉｊ The total number of combinations of the ith hard phase particle 5i and the jth hard phase particle 5j that are determined to satisfy the relationship <D is calculated as n2.

[0031] When the hard phase particles satisfy the relationship n2<n1, the number of adjacent or contacting hard phase particle combinations is smaller than the total number of hard phase particles contained in the cross section of the substrate 2. In this case, the hard phase particles are considered to be better dispersed in the cross section of the substrate 2. This reduces or prevents crack propagation at the interfaces between adjacent or contacting hard phase particles. This accordingly improves the wear resistance and fracture resistance of the substrate 2. This improves the wear resistance and fracture resistance of the cermet tool 1.

[0032] Binary processing and extraction processing of backscattered electron images of cross sections taken by a scanning electron microscope, D and R for multiple hard phase particles ｉｊImage processing software can be used to calculate n1 and n2 for the plurality of hard phase particles. For example, WINROOF2021 can be used as such image processing software.

[0033] For example, the plurality of hard phase particles satisfy the relationship n2<(n1 / 2) in the cross section of the substrate 2.

[0034] When the plurality of hard phase particles satisfy the relationship n2<(n1 / 2), the number of combinations of adjacent or contacting hard phase particles is even smaller than the number of hard phase particles contained in the cross section of the substrate 2. In this case, the plurality of hard phase particles is considered to be more favorably dispersed in the cross section of the substrate 2. This can further reduce or prevent crack propagation at the interfaces between adjacent or contacting hard phase particles. Accordingly, the wear resistance and fracture resistance of the substrate 2 can be further improved. Therefore, the wear resistance and fracture resistance of the cermet tool 1 can be further improved.

[0035] For example, the plurality of hard phase particles may be arranged in a cross section of the substrate 2 such that R ｉｊ > 0. Here, i and j are any natural numbers that satisfy i, j ≦ n1 and i < j or j < i. ｉｊ > 0" means that a plurality of hard phase particles satisfy the relationship R ｉｊ = 0, that is, the plurality of hard phase particles are separated and do not come into contact with each other. When there are a plurality of hard phases in contact with each other, these plurality of hard phases may be regarded as a single unit and as a single hard phase particle.

[0036] A plurality of hard phase particles are ｉｊ When the relationship of ∫ ...

[0037] The binder phase 6 includes a plurality of binder phase particles. For example, the binder phase 6 is composed of a plurality of binder phase particles. For example, the average particle diameter D of the plurality of hard phase particles contained in the cross section of the substrate 2 is smaller than the average particle diameter of the plurality of binder phase particles contained in the cross section of the substrate 2.

[0038] The average particle size of the plurality of binder phase particles contained in the cross section of the substrate 2 can also be calculated in the same manner as the average particle size D of the plurality of hard phase particles contained in the cross section of the substrate 2. However, the binarization process in calculating the average particle size of the plurality of binder phase particles may be performed, for example, by coloring the image of the binder phase 6 black and the images of the hard phase 5 and the solid solution phase 7 white in a backscattered electron image of the cross section taken by a scanning electron microscope. The extraction process in calculating the average particle size of the plurality of binder phase particles may be performed, for example, by extracting a plurality of binder phase particles having particle sizes within 90% of the maximum particle size in the particle size distribution of the plurality of binder phase particles. The particle size of the binder phase particle contained in the cross section of the substrate 2 is calculated as the diameter of the largest circumscribed circle centered on the center of the binder phase particle. The average particle size of the plurality of binder phase particles is calculated as the average value of the particle sizes of the plurality of binder phase particles contained in the cross section of the substrate 2.

[0039] When the average particle diameter D of the hard phase particles contained in the cross section of the substrate 2 is smaller than the average particle diameter D of the binder phase particles contained in the cross section of the substrate 2, the number of adjacent or contacting hard phase particles can be more easily reduced. That is, the hard phase particles can be more easily dispersed in the cross section of the substrate 2. This makes it easier to reduce or prevent crack propagation at the interfaces between adjacent or contacting hard phase particles. Accordingly, the wear resistance and fracture resistance of the substrate 2 can be more easily improved. Therefore, the wear resistance and fracture resistance of the cermet tool 1 can be more easily improved.

[0040] For example, the plurality of hard phase particles are surrounded by the solid solution phase 7 and separated from the binder phase 6 in the cross section of the substrate 2. Here, "the plurality of hard phase particles are surrounded by the solid solution phase 7 and separated from the binder phase 6 in the cross section of the substrate 2" means, for example, that at least 95% of the plurality of hard phase particles are surrounded by the solid solution phase 7 and separated from the binder phase 6 in the cross section of the substrate 2.

[0041] When the plurality of hard phase particles are surrounded by the solid solution phase 7 and separated from the binder phase 6, it is possible to reduce the difference between the thermal expansion coefficient of the plurality of hard phase particles and the thermal expansion coefficient of the solid solution phase 7, and the difference between the thermal expansion coefficient of the solid solution phase 7 and the thermal expansion coefficient of the binder phase 6. This makes it possible to improve the bonding strength between the plurality of hard phase particles and the solid solution phase 7, and between the solid solution phase 7 and the binder phase 6. Accordingly, it is possible to further improve the wear resistance and fracture resistance of the substrate 2. That is, it is possible to further improve the wear resistance and fracture resistance of the cermet tool 1.

[0042] (Coating layer 3) The coating layer 3 coats the base 2 for the purpose of improving the abrasion resistance, heat resistance, etc. of the base 2. While Fig. 2 shows an example in which the coating layer 3 covers the entire surface of the base 2, the coating layer 3 does not necessarily have to cover the entire surface of the base 2. The coating layer 3 only needs to be located on at least a portion of the surface of the base 2. When the coating layer 3 is located on the first surface (here, the upper surface) of the base 2, the abrasion resistance and heat resistance of the first surface are high. When the coating layer 3 is located on the second surface (here, the side surface) of the base 2, the abrasion resistance and heat resistance of the second surface are high.

[0043] The coating layer 3 may be composed of, for example, at least one metal element selected from the group 4, 5, and 6 elements of the periodic table, aluminum (Al), and silicon (Si), and at least one nonmetal element selected from carbon (C), nitrogen (N), and oxygen (O). This configuration improves the oxidation resistance of the coating layer 3, further improving the wear resistance of the coating layer 3. The coating layer 3 may be a single layer. The cermet tool 1 may also have a layered coating layer 3, i.e., two or more layers.

[0044] (Manufacturing Method) Next, a method for manufacturing the substrate 2 made of the cermet according to the embodiment will be described.

[0045] First, a plurality of raw material powders are mixed to prepare a mixed powder. Specifically, the mixed powder is a TiCN powder having an average particle size of 0.1 μm to 1.2 μm, a WC powder having an average particle size of 0.1 μm to 2.5 μm, and a Cr powder having an average particle size of 2 μm to 4 μm. ３ C ２ powders and carbide powders of metals of groups 4, 5, and 6 of the periodic table (TiCN, WC, and Cr ３ C ２ excluding the above), at least one of nitride powder and carbonitride powder, and metal W powder and WC powder having an average particle size of 3 μm to 15 μm. １－ｘ (0<x≦1) and at least one powder of the formula (I) to prepare a mixed powder.

[0046] Here, the average particle size of the TiCN powder may be 0.3 μm or more and 0.9 μm or less. １－ｘ At least one of the powders (0<x≦1) may be present in an amount of 1 mass % or more and 20 mass % or less relative to the total amount of the mixed powder. Carbon powder may be added to the mixed powder, and a predetermined amount of MnCO 3 having an average particle size of 0.5 μm or more and 5 μm or less may be added to the mixed powder. ３ Powders may also be added.

[0047] In this embodiment, at least one of the carbide powder, nitride powder, and carbonitride powder of metals of Groups 4, 5, and 6 of the periodic table other than TiCN is selected from the group consisting of TiC powder, TiN powder, WC powder, NbC powder, Mo powder, and the like, each having an average particle size of 0.1 μm or more and 3 μm or less. ２ C powder, TaC powder, VC powder or ZrC powder may be applied.

[0048] The mixed powder is prepared by adding an organic binder and / or a solvent to the raw material powder and mixing the resulting mixture using a known mixing method such as a ball mill, a vibration mill, a jet mill, an attritor mill, etc. When powder mixing is performed using an attritor mill, the raw material powder is pulverized to reduce the particle size, but metal powders tend to be difficult to pulverize due to their high ductility.

[0049] Next, a predetermined amount of at least one of metallic Co powder and / or metallic Ni powder having an average particle size of 0.5 μm to 5 μm is added to the mixed powder prepared above, and the mixture is mixed and dried by the known mixing method described above to prepare a mixed powder.

[0050] The resulting mixed powder is molded into a molded body of a predetermined shape by a known molding method such as press molding, extrusion molding, or injection molding.

[0051] Next, the compact is fired in a vacuum or in an inert gas atmosphere. In this embodiment, the cermet having the predetermined structure described above can be produced by firing under the following conditions: (a) Raise the temperature from room temperature to 450°C and maintain the temperature at 450°C for 0.5 to 2 hours; (b) Raise the temperature from 450°C to 1000°C to 1100°C; (c) Raise the temperature in a vacuum from 1000°C to 1100°C to a firing temperature T1 of 1280°C to 1380°C at a first heating rate of 0.1°C / min to 10°C / min; (d) Raise the temperature in a vacuum or in an inert gas atmosphere of 30 Pa to 20,000 Pa from the firing temperature T1 to a firing temperature T2 of 1500°C to 1600°C at a second heating rate of 4°C / min to 15°C / min. (e) Maintain the baking temperature T2 for 0.5 hours to 2 hours in a vacuum or in an inert gas atmosphere of 30 Pa to 20,000 Pa. (f) Lower the temperature at a rate e of 5°C / min to 40°C / min in a vacuum or in an inert gas atmosphere of 30 Pa to 20,000 Pa.

[0052] Thereafter, if necessary, a coating layer 3 may be provided on the substrate 2. The coating layer 3 may be a so-called hard film, and may be formed by, for example, a PVD method or a CVD method. The coating layer 3 may be a single layer film or a laminated film.

[0053] <Cutting Tool> Next, the configuration of a cutting tool including the above-described cermet tool 1 will be described with reference to Fig. 5. Fig. 5 is a front view showing an example of a cutting tool according to an embodiment.

[0054] As shown in FIG. 5 , the cutting tool 100 according to the embodiment includes the cermet tool 1 and a holder 70 for fixing the cermet tool 1 .

[0055] The holder 70 is a rod-shaped member extending from its front end (upper end in FIG. 5 ) to its rear end (lower end in FIG. 5 ). The holder 70 is made of, for example, steel or cast iron. Among these materials, steel, for example, is used, as it has high toughness.

[0056] The holder 70 has a pocket 73 located at the end on the tip side. The pocket 73 is the portion where the cermet tool 1 is attached, and has a seating surface that intersects with the rotation direction of the workpiece and a constraint side surface that is inclined relative to the seating surface. The seating surface is provided with a screw hole into which a screw 75, which will be described later, is threaded.

[0057] The cermet tool 1 is positioned in a pocket 73 of the holder 70 and attached to the holder 70 by a screw 75. That is, the screw 75 is inserted into the through hole 21 of the cermet tool 1, and the tip of the screw 75 is inserted into a threaded hole formed in the seating surface of the pocket 73 to screw the threaded portions together. In this way, the cermet tool 1 is attached to the holder 70 so that the cutting edge portion protrudes outward from the holder 70.

[0058] In the embodiment, a cutting tool 100 used for so-called turning is exemplified. Examples of turning include internal diameter machining, external diameter machining, and grooving. The cutting tool is not limited to that used for turning. For example, the cermet tool 1 may be used as a cutting tool used for milling. Examples of cutting tools used for milling include milling cutters such as flat milling cutters, face milling cutters, side milling cutters, and groove milling cutters, and end mills such as single-blade end mills, multi-blade end mills, tapered-blade end mills, and ball end mills.

[0059] Examples of the present disclosure will be specifically described below, but the present disclosure is not limited to the examples shown below.

[0060] A substrate according to the example was manufactured according to the method for manufacturing the substrate 2 made of the cermet according to the embodiment as described above.

[0061] First, 60% by mass of TiCN powder having an average particle size of 1 μm, 10% by mass of WC powder having an average particle size of 1 μm, 6% by mass of NbC powder having an average particle size of 1 μm, and 6% by mass of Mo powder having an average particle size of 3 μm were mixed. ２ The powder C was mixed with isopropyl alcohol (IPA) to obtain a first mixed powder.

[0062] Next, 2 mass % of Cr having an average particle size of 3 μm was added to the obtained first mixed powder. ３ C ２ The powder, 8 mass % of Ni powder having an average particle size of 3 μm, and 8 mass % of metal Co powder having an average particle size of 3 μm were added, and the mixture was mixed using IPA and dried to obtain a second mixed powder.

[0063] The obtained second mixed powder was press-molded to form a block-shaped compact. Subsequently, the compact was fired under the following conditions to obtain a substrate according to the example. (a) The temperature was increased from room temperature to 450°C and maintained at 450°C for two hours. (b) The temperature was further increased from 450°C to 1100°C. (c) In a vacuum, the temperature was increased from 1100°C to a firing temperature T1 of 1350°C at a first heating rate of 3°C / min. (d) In a nitrogen atmosphere at a pressure of 1000 Pa, the temperature was increased from the firing temperature T1 to a firing temperature T2 of 1550°C at a second heating rate of 10°C / min. (e) In a nitrogen atmosphere, the firing temperature T2 was maintained for one hour. (f) In an argon atmosphere, the temperature was decreased at a temperature decrease rate e of 10°C / min.

[0064] Fig. 6 is a scanning electron microscope photograph of a cross section of a substrate according to an example. Fig. 7 is an image of a plurality of hard phase particles extracted from a cross section of a substrate according to an example. Fig. 8 is an R of a plurality of hard phase particles extracted from a cross section of a substrate according to an example. ｉｊ 9 is an image showing the analysis results of Fig. 9. A conventional substrate was prepared as a substrate according to a comparative example. Fig. 9 is a scanning electron microscope photograph of a cross section of the substrate according to the comparative example.

[0065] 6 and 9, it was confirmed that both the substrates according to the examples and the substrates according to the comparative examples contained a hard phase shown in black, a binder phase shown in white, and a solid solution phase shown in gray-white. It was also confirmed that in both the substrates according to the examples and the substrates according to the comparative examples, the hard phase was composed of a plurality of hard phase particles, and the binder phase was composed of a plurality of binder phase particles.

[0066] Next, the D and R values ​​of the hard phase particles constituting the hard phase contained in the substrate according to the example are ｉｊ , n1, and n2 were calculated. A binarization process for emphasizing the plurality of hard phase particles and an extraction process for extracting the plurality of hard phase particles having particle diameters within 90% of the maximum particle diameter in the particle diameter distribution were performed on the backscattered electron image of the cross section of the substrate according to the example as shown in FIG. 6. As a result, an image of the extracted plurality of hard phase particles as shown in FIG. 7 was obtained. The image shown in FIG. 7 was subjected to image processing software (WINROOF2021) to calculate D and R for the plurality of hard phase particles. ｉｊ , n1, and n2 were calculated. For example, the R ｉｊ Here, D and n1 were 0.2573 μm and 241 pieces, respectively. The calculated D and R ｉｊ The calculated n2 was 95.

[0067] On the other hand, the D and R values ​​of the plurality of hard phase particles constituting the hard phase contained in the substrate according to the comparative example were also measured in the same manner. ｉｊ , n1, and n2 were calculated. Here, D and n1 were 0.3941 μm and 385 pieces, respectively. The calculated D and R ｉｊ The calculated n2 was 844.

[0068] In the substrates according to the examples, it was confirmed that the plurality of hard phase particles satisfied the relationship n2<n1 in the cross section of the substrate, whereas in the substrates according to the comparative examples, it was confirmed that the plurality of hard phase particles did not satisfy the relationship n2<n1 in the cross section of the substrate.

[0069] In the substrates according to the examples, it was confirmed that the plurality of hard phase particles satisfied the relationship n2<(n1 / 2) in the cross section of the substrate. On the other hand, in the substrates according to the comparative examples, it was confirmed that the plurality of hard phase particles did not satisfy the relationship n2<(n1 / 2) in the cross section of the substrate.

[0070] In the substrate according to the example, the plurality of hard phase particles are arranged in a cross section of the substrate in the shape of R ｉｊ On the other hand, in the substrate according to the comparative example, the plurality of hard phase particles satisfies the relationship R ｉｊ It was confirmed that the relationship of .gtoreq.0 may not be satisfied.

[0071] In the substrates according to the examples, it was confirmed that the average particle size of the plurality of hard phase particles contained in the cross section of the substrate was smaller than the average particle size of the plurality of binder phase particles contained in the cross section of the substrate.It was also confirmed that in the substrates according to the comparative examples, the average particle size of the plurality of hard phase particles contained in the cross section of the substrate was smaller than the average particle size of the plurality of binder phase particles contained in the cross section of the substrate.

[0072] In the substrates according to the examples, it was confirmed that the majority of the hard phase particles were surrounded by the solid solution phase and separated from the binder phase in the cross section of the substrate, whereas in the gases according to the comparative examples, it was confirmed that the majority of the hard phase particles were not surrounded by the solid solution phase and were in contact with the hard phase particles or the binder phase in the cross section of the substrate.

[0073] Next, a fracture resistance test was carried out on the cermet tool including the substrate according to the example and the cermet tool including the substrate according to the comparative example under the following conditions.

[0074] <Fracture resistance test (turning)> Workpiece: S45C φ200 (25 mm wide grooves x 4) Cutting speed: 250 m / min Feed: 0.25 mm / rev Depth of cut: 1.0 mm Cutting condition: Wet Evaluation method: Number of impacts (times) until fracture

[0075] The number of impacts until the cermet tool including the substrate according to the example fractured was about 2000. On the other hand, the number of impacts until the cermet tool including the substrate according to the comparative example fractured was about 1300. Thus, it was confirmed that the cermet tool including the substrate according to the example has improved fracture resistance compared to the cermet tool including the substrate according to the comparative example.

[0076] As described above, there is provided a cermet tool (for example, the cermet tool 1) including a substrate (for example, the substrate 2), wherein the substrate includes a hard phase (for example, the hard phase 5) containing Ti, a binder phase (for example, the binder phase 6) containing at least one of Ni and Co, and a solid solution phase (for example, the solid solution phase 7) containing Ti and W, and the hard phase includes a plurality of hard phase particles, and the plurality of hard phase particles satisfy the relationship n2<n1 in a cross section of the substrate, where n1 represents the number of the plurality of hard phase particles included in the cross section of the substrate, and n2 represents the number of R included in the cross section of the substrate. ｉｊ <D represents the number of hard phase particles that satisfy the relationship, D represents the average particle diameter of the hard phase particles contained in the cross section of the substrate, and R ｉｊ indicates the distance between the ith hard phase particle and the jth hard phase particle among the plurality of hard phase particles contained in the cross section of the substrate, and i and j are natural numbers satisfying i, j≦n1 and i<j or j<i.

[0077] Therefore, the cermet tool according to the embodiment can improve the wear resistance and fracture resistance.

[0078] 1 is merely an example and does not limit the shape of the cermet tool according to the present disclosure. The cermet tool according to the present disclosure may, for example, have a rod-shaped body having a rotation axis and extending from a front end to a rear end, a cutting edge located at a first end of the body, and a groove extending spirally from the cutting edge toward a second end of the body.

[0079] Although an example of using the cermet as a tool has been described here, the use of the cermet according to the present disclosure is not limited to tools.

[0080] Supplementary Note (1): A cermet tool including a substrate, wherein the substrate includes a hard phase containing Ti, a binder phase containing at least one of Ni and Co, and a solid solution phase containing Ti and W, wherein the hard phase includes a plurality of hard phase particles, and the plurality of hard phase particles satisfy a relationship of n2<n1 in a cross section of the substrate, n1 represents the number of the plurality of hard phase particles included in the cross section of the substrate, and n2 represents the number of R included in the cross section of the substrate. ｉｊ <D represents the number of the plurality of hard phase particles that satisfy the relationship, D represents the average particle diameter of the plurality of hard phase particles contained in the cross section of the substrate, and R ｉｊ indicates a distance between the ith hard phase particle and the jth hard phase particle among the plurality of hard phase particles included in the cross section of the base, and i and j are natural numbers satisfying i, j≦n1 and i<j or j<i. Supplementary Note (2): The cermet tool according to Supplementary Note (1), wherein the plurality of hard phase particles satisfy the relationship n2<(n1 / 2) in the cross section of the base. Supplementary Note (3): The plurality of hard phase particles satisfy the relationship n2<(n1 / 2) in the cross section of the base. ｉｊ >0. Appendix (4): The cermet tool according to any one of Appendixes (1) to (3), wherein the binder phase includes a plurality of binder phase particles, and wherein an average particle size of the plurality of hard phase particles included in the cross section of the substrate is smaller than an average particle size of the plurality of binder phase particles included in the cross section of the substrate. Appendix (5): The cermet tool according to any one of Appendixes (1) to (4), wherein the plurality of hard phase particles are surrounded by the solid solution phase and separated from the binder phase in the cross section of the substrate. Appendix (6): The cermet tool according to any one of Appendixes (1) to (5), further comprising a coating layer coating the substrate. Appendix (7): A cutting tool comprising: a holder extending from a front end to a rear end and having a pocket located on the front end side; and the cermet tool according to any one of Appendixes (1) to (6) located in the pocket.

[0081] Further advantages and / or modifications may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

[0082] REFERENCE SIGNS LIST 1 cermet tool 2 substrate 3 coating layer 5 hard phase 5i i-th hard phase particle 5j j-th hard phase particle 6 binder phase 7 solid solution phase 21 through hole 70 holder 73 pocket 75 screw 100 cutting tool

Claims

1. A cermet tool comprising a base, The aforementioned substrate is A hard phase containing Ti, A bonded phase containing at least one of Ni and Co, A solid solution phase containing Ti and W, Includes, The hard phase includes a plurality of hard phase particles, The plurality of hard phase particles satisfy the relationship n2 < n1 in the cross-section of the substrate. n1 indicates the number of the plurality of hard phase particles contained in the cross-section of the substrate, n2 is R included in the cross-section of the substrate. ｉｊ <The number of hard phase particles that satisfy relationship D is shown below.> D represents the average particle diameter of the plurality of hard phase particles contained in the cross-section of the substrate. R ｉｊ This indicates the distance between the i-th hard phase particle and the j-th hard phase particle among the plurality of hard phase particles contained in the cross-section of the substrate. i and j are natural numbers satisfying i, j ≤ n1 and i < j or j < i. Cermet tools.

2. The plurality of hard phase particles satisfy the relationship n2 < (n1 / 2) in the cross-section of the substrate. The cermet tool according to claim 1.

3. The plurality of hard phase particles, in the cross-section of the substrate, R ｉｊ Satisfying the relationship > 0, The cermet tool according to claim 1.

4. The aforementioned bonded phase comprises a plurality of bonded phase particles, The average particle diameter of the multiple hard phase particles contained in the cross-section of the substrate is smaller than the average particle diameter of the multiple binding phase particles contained in the cross-section of the substrate. The cermet tool according to claim 1.

5. The plurality of hard phase particles are surrounded by the solid solution phase and separated from the binding phase in the cross-section of the substrate. The cermet tool according to claim 1.

6. The substrate further comprises a coating layer covering the substrate, The cermet tool according to claim 1.

7. A holder having a pocket that extends from the tip towards the rear end and is located on the side of the tip, A cermet tool according to any one of claims 1 to 6 located in the aforementioned pocket, A cutting tool equipped with the following features.