Cermet member, cutting insert, and cutting tool

Abstract

A cermet member according to the present disclosure comprises a substrate that has: a plurality of hard phases containing a solid solution phase containing Ti, W, and C; and a plurality of binding phases that bind mutually adjacent hard phases. The substrate is divided into a first region located at a depth of up to 20 μm from the surface and a second region located deeper than the first region. The plurality of hard phases include: a plurality of first hard phases in which core particles containing TiCN as the main component are included in a solid solution phase; and a plurality of second hard phases composed only of the solid solution phase. In the first region, the carbon content C121 of the outer portion of the second hard phases is higher than the carbon content C122 of the inner portion of the second hard phases, and in the second region, the carbon content C221 of the outer portion of the second hard phases is lower than the carbon content C222 of the inner portion of the second hard phases.

Description

Cermet components, cutting inserts, and cutting tools

[0001] This disclosure relates to cermet members, cutting inserts, and cutting tools.

[0002] An example of a cutting tool used when machining a workpiece is the cutting tool described in Patent Document 1. The cutting tool described in Patent Document 1 comprises a substrate made of cermet. This substrate has a hard phase substantially made of titanium carbonitride (TiCN), a solid solution phase made of a composite carbonitride containing titanium and tungsten, and a bonding phase mainly composed of iron group elements such as cobalt and nickel.

[0003] Japanese Patent Publication No. 2013-010997

[0004] The cermet member of this disclosure comprises a substrate having a plurality of hard phases containing a solid solution phase including Ti, W, and C, and a plurality of binding phases that bond adjacent hard phases to each other. The substrate is divided into a first region located to a depth of 20 μm from the surface and a second region located deeper than the first region. The plurality of hard phases include a plurality of first hard phases in which core particles mainly composed of TiCN are embedded in the solid solution phase, and a plurality of second hard phases composed only of the solid solution phase. The second hard phase is divided into an inner portion located in the range from the center of the second hard phase to (2 / 3)R, when the radius of the second hard phase is R, and an outer portion located outside the inner portion. In the first region, the carbon content C in the outer portion of the second hard phase １２１ This is the carbon content C in the inner portion of the second hard phase. １２２ Higher than the above, and in the second region, the carbon content C in the outer portion of the second hard phase ２２１ This is the carbon content C in the inner portion of the second hard phase. ２２２ It is lower than that.

[0005] Figure 1 is a perspective view showing an example of a cermet member according to the embodiment. Figure 2 is a side cross-sectional view showing an example of a cermet member according to the embodiment. Figure 3 is a schematic scanning electron microscope image of a cross-section of a cermet member according to the embodiment. Figure 4 is a diagram for explaining the inner and outer portions of the second hard phase according to the embodiment. Figure 5 is a front view showing an example of a cutting tool according to the embodiment. Figure 6 is a scanning electron microscope image of a cross-section of a cermet member according to the embodiment.

[0006] The embodiments for implementing the cermet members, cutting inserts, and cutting tools according to this disclosure (hereinafter referred to as "embodiments") will be described in detail below with reference to the drawings. Note that these embodiments do not limit the cermet members, cutting inserts, and cutting tools according to this disclosure. Each embodiment can be combined as appropriate, provided that the processing content is not inconsistent. The same parts are denoted by the same reference numerals in the following embodiments, and redundant descriptions are omitted.

[0007] An example of a cutting tool used when machining a workpiece is the cutting tool described in Patent Document 1. The cutting tool described in Patent Document 1 comprises a substrate made of cermet. This substrate has a hard phase substantially made of titanium carbonitride (TiCN), a solid solution phase made of a composite carbonitride containing titanium and tungsten, and a bonding phase mainly composed of iron group elements such as cobalt and nickel.

[0008] However, conventional technology still had room for improvement in terms of enhancing the durability of the substrate. Therefore, there is a need for a technology that can solve the above problems and improve the durability of the substrate.

[0009] <Cermet Member> Figure 1 is a perspective view showing an example of a cermet member 1 according to the embodiment. Figure 2 is a side cross-sectional view showing an example of a cermet member 1 according to the embodiment. The cermet member 1 is also an example of a cutting insert. As shown in Figures 1 and 2, the cermet member 1 according to the embodiment may include a substrate 2 and a coating layer 3.

[0010] The base body 2 may have a hexahedron shape in which the top and bottom surfaces (the surfaces intersecting the Z-axis as shown in Figure 1) are parallelograms. One corner of the base body 2 may function as a cutting edge. This cutting edge may include a first surface (e.g., the top surface) and a second surface (e.g., the side surface) connected to this first surface.

[0011] In this embodiment, the first surface may function as a "scooping surface" for scooping up chips generated by cutting, and the second surface may function as a "relief surface". Cutting edges may be located on at least a portion of the ridge where the first and second surfaces intersect. The cermet member 1 may cut the workpiece by applying these cutting edges to the workpiece.

[0012] A through-hole 21 may be located in the center of the base body 2, penetrating it vertically. In this case, a screw 75 (see Figure 5) for attaching the cermet member 1 to a holder 70 (see Figure 5), which will be described later, may be inserted into the through-hole 21.

[0013] The substrate 2 may be composed of a cermet. This cermet may contain Ti (titanium) and W (tungsten), as well as at least one of Co (cobalt) and Ni (nickel). The detailed composition of the substrate 2 will be described later.

[0014] The coating layer 3 may cover at least a portion of the surface of the substrate 2. Although the example in Figure 2 shows the case where the coating layer 3 completely covers the surface of the substrate 2, the coating layer 3 does not necessarily need to cover the entire surface of the substrate 2.

[0015] The coating layer 3 may have functions to improve the wear resistance and heat resistance of the substrate 2. For example, if the coating layer 3 is located on the first surface of the substrate 2, the wear resistance and heat resistance of the first surface will be improved. Also, if the coating layer 3 is located on the second surface of the substrate 2, the wear resistance and heat resistance of the second surface will be improved.

[0016] The coating layer 3 may be composed of, for example, at least one metallic element from among the Group 4, Group 5, and Group 6 elements of the periodic table, Al (aluminum), and Si (silicon), and at least one nonmetallic element from among C (carbon), N (nitrogen), and O (oxygen).

[0017] With this configuration, the oxidation resistance of the coating layer 3 is improved, and therefore the abrasion resistance of the coating layer 3 is further improved. The coating layer 3 may be one layer or two or more layers. Furthermore, the cermet member 1 according to this embodiment does not have to have a coating layer 3.

[0018] Figure 3 is a schematic scanning electron microscope image of a cross-section of the cermet member 1 according to the embodiment. As shown in Figure 3, the substrate 2 composed of cermet may have a plurality of hard phases 5 and a plurality of binding phases 8.

[0019] The hard phase 5 may contain a solid solution phase containing Ti, W, and C. The hard phase 5 may have a first hard phase 6 and a second hard phase 7. The first hard phase 6 may have core particles 6a and a solid solution phase 6b, and the core particles 6a may be encapsulated within the solid solution phase 6b. The second hard phase 7 may consist only of a solid solution phase. That is, the second hard phase 7 may be an example of a solid solution phase.

[0020] The core particles 6a may contain Ti. The core particles 6a may contain at least one compound from among Ti carbides, nitrides, and carbonitrides. The core particles 6a may contain TiCN (titanium carbonitride) as a main component. In this disclosure, "main component" means, for example, that the ratio of the mass of the component to the total mass of the components constituting the phase in question is 55% by mass or more.

[0021] The core particle 6a may contain Ti, W, and at least one element from the Group 4, Group 5, and Group 6 elements of the periodic table other than Ti and W (hereinafter also referred to as "Group 4 to Group 6 elements"). The Ti content in the metallic elements contained in the core particle 6a may be 80% by mass or more. The total content of W and Group 4 to Group 6 elements in the metallic elements contained in the core particle 6a may be 1% by mass to 15% by mass.

[0022] The core particle 6a may contain at least one element from Co and Ni as the remainder. The total content of Ti, W, group 4 to 6 elements, Co, and Ni in the metal elements contained in the core particle 6a may be 100% by mass.

[0023] The solid solution phase 6b and the second hard phase 7 may contain Ti, W, and C. The solid solution phase 6b and the second hard phase 7 may be a solid solution containing at least one compound from among Ti carbides, nitrides, and carbonitrides, at least one compound from among W carbides, nitrides, and carbonitrides, and at least one compound from among carbides, nitrides, and carbonitrides of at least one element from group 4 to 6.

[0024] The solid solution phase 6b and the second hard phase 7 may contain Ti, W, at least one element from groups 4 to 6, and at least one element from Ni and Co.

[0025] The Ti content in the metallic elements contained in the solid solution phase 6b and the second hard phase 7 may be 30% to 70% by mass. The total content of W and group 4 to 6 elements in the metallic elements contained in the solid solution phase 6b and the second hard phase 7 may be 30% to 70% by mass.

[0026] The total content of Ni and Co in the metallic elements contained in the solid solution phase 6b and the second hard phase 7 may be 0% to 3% by mass. The total content of Ti, W, group 4 to 6 elements, Co, and Ni in the metallic elements contained in the solid solution phase 6b and the second hard phase 7 may be 100% by mass.

[0027] The bonding phase 8 may bond adjacent hard phases 5 together. Alternatively, the bonding phase 8 may bond core particles 6a to solid solution phase 6b or the second hard phase 7. The bonding phase 8 may contain at least one element from Ni and Co. The bonding phase 8 may contain at least one element from Ni and Co, and W.

[0028] As shown in Figure 3, the cross-section of the substrate 2 in this disclosure may be any cross-section that allows confirmation of the surface of the substrate 2, for example, the interface 10 between the substrate 2 and the coating layer 3, as well as confirmation of a plurality of first hard phases 6, a plurality of second hard phases 7, and a plurality of bonding phases 8. The interface 10 is an example of a surface.

[0029] The cross-section of the substrate 2 in this disclosure may be a backscattered electron image of the cross-section captured by a scanning electron microscope (SEM). In this backscattered electron image, the core particles 6a are observed to be darker than, for example, the solid solution phase 6b and the second hard phase 7.

[0030] Furthermore, the binding phase 8 is observed to be whiter than, for example, the solid solution phase 6b and the second hard phase 7. In addition, the solid solution phase 6b and the second hard phase 7 are observed to be gray, for example, between the color of the hard phase 5 and the color of the binding phase 8. The cross-section of the substrate 2 in this disclosure may be, for example, a cross-section of size 100 μm × 100 μm.

[0031] To identify each of the multiple core particles 6a, for example, electron backscatter diffraction (EBSD) in a scanning electron microscope can be used.

[0032] Specifically, an electron beam is irradiated onto the cross-section of the substrate 2 using a scanning electron microscope, and the reflected electrons 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 multiple core particles 6a. By obtaining information about the crystal orientation of each of the multiple core particles 6a from this pattern, each of the multiple core particles 6a can be identified.

[0033] Similarly, to distinguish between each of the multiple solid solution phases 6b, the multiple second hard phases 7, or the multiple binding phases 8, for example, electron backscatter diffraction in a scanning electron microscope can be used.

[0034] Specifically, by irradiating a cross-section of the substrate 2 with an electron beam using a scanning electron microscope and receiving the reflected electrons from the cross-section of the substrate 2 with a fluorescent screen, a Kikuchi pattern reflecting the respective crystal structures of multiple solid solution phases 6b, multiple second hard phases 7, or multiple bonding phases 8 is obtained.

[0035] By obtaining information about the crystal orientation of each of the multiple solid solution phases 6b, multiple second hard phases 7, or multiple bonding phases 8 from this pattern, each of the multiple solid solution phases 6b, multiple second hard phases 7, or multiple bonding phases 8 can be identified.

[0036] In this embodiment, the substrate 2 may be divided into a first region and a second region. The first region of the substrate 2 is a region located on the surface of the substrate 2, for example, at a depth of 10 to 20 μm from the interface between the substrate 2 and the coating layer 3. The second region of the substrate 2 is a region located deeper than the first region.

[0037] Furthermore, in this embodiment, as shown in Figure 4, the second hard phase 7, which is composed solely of the solid solution phase, may be divided into an inner portion 7a and an outer portion 7b. Figure 4 is a diagram illustrating the inner portion 7a and the outer portion 7b of the second hard phase 7 according to this embodiment.

[0038] As shown in Figure 4, in this embodiment, a circumscribed circle C1 is individually set for each second hard phase 7. The center C of the set circumscribed circle C1 is considered to be the center C of the corresponding second hard phase 7.

[0039] Furthermore, when the radius of the circumscribed circle C1 is R, the inner portion 7a may be located in the range from the center C of the second hard phase 7 to (2 / 3)R. That is, the inner portion 7a may be located inside a circle C2 whose center is C and whose radius is (2 / 3)R.

[0040] On the other hand, the outer portion 7b may be located further outward than the inner portion 7a in the second hard phase 7. That is, the outer portion 7b may be located outside the circle C2 described above in the second hard phase 7.

[0041] In the embodiment, in the first region close to the surface of the base body 2, the carbon content C in the outer portion 7b of the second hard phase 7 １２１ may be higher than the carbon content C in the inner portion 7a of the second hard phase 7 １２２ . Furthermore, in the embodiment, in the second region far from the surface of the base body 2, the carbon content C in the outer portion 7b of the second hard phase 7 ２２１ may be lower than the carbon content C in the inner portion 7a of the second hard phase 7 ２２２ . It should be noted that the "content" in the present disclosure is to be evaluated in atomic percent.

[0042] The base body 2 in the embodiment contains core particles 6a included in the first hard phase 6, and a solid solution phase included in the first hard phase 6 and the second hard phase 7. Since the base body 2 contains core particles 6a mainly composed of TiCN, the hardness of the base body 2 can be improved. In addition, since the base body 2 contains a solid solution phase 6b containing Ti, W and N, the toughness of the base body 2 can be improved.

[0043] Furthermore, since the core particles 6a are encapsulated in the solid solution phase 6b excellent in toughness in the first hard phase 6, cracks are less likely to occur in the vicinity of the core particles 6a. In addition, since the core particles 6a are encapsulated in the solid solution phase 6b which has better affinity to the binder phase 8 than the first hard phase 6, the bonding property between the first hard phase 6 and the binder phase 8 is improved.

[0044] Since such first hard phase 6 and second hard phase 7 are present respectively in the first region located outward in the base body 2 and the second region located inward in the base body 2, variations in hardness and toughness in the base body 2 are suppressed, and the overall hardness and toughness of the base body 2 are improved.

[0045] As described above, in the second hard phase 7 in the first region, the carbon content C in the outer portion 7b １２１ and the carbon content C in the inner portion 7a１２２ If the relative value is higher than the given value, the proportion of C-containing Ti compounds (e.g., TiC and TiCN) in the outer portion 7b can be increased. C-containing Ti compounds have a higher Vickers hardness compared to C-free Ti compounds (e.g., TiN). Therefore, this has the effect of improving the Vickers hardness of the outer portion 7b in the second hard phase 7 of the first region.

[0046] As the Vickers hardness of the outer portion 7b of the second hard phase 7 in the first region improves, the overall Vickers hardness of the first region improves. As described above, the first region is located on the surface side of the substrate 2. Because the overall Vickers hardness of this first region is high, the wear resistance of the substrate 2 is improved, and the durability of the substrate 2 can be improved.

[0047] In addition, as described above, in the second hard phase 7 in the second region, the carbon content C in the outer portion 7b ２２１ The carbon content C in the inner portion 7a ２２２ If the carbon content in the inner portion 7a is relatively lower than the ratio of carbon in the inner portion 7a, the proportion of carbon-containing Ti compounds (e.g., TiC and TiCN) in the outer portion 7b can be reduced. ２２２ The relatively high value ensures the overall strength of the second hard phase 7 in the second region.

[0048] Furthermore, the carbon content C in the outer portion 7b ２２１ The relatively low coefficient of friction enhances the flexibility of the second hard phase 7 in the second region. As a result, even if a crack occurs in the substrate 2 during use of the cermet member 1 (for example, during machining), the crack is less likely to propagate in the second region. From this perspective as well, the durability of the substrate 2 can be improved.

[0049] Furthermore, in the embodiment, the carbon content C in the solid solution phase 6b of the first hard phase 6 in the first region near the surface of the substrate 2 １１１ However, the carbon content C in the core particles 6a of the first hard phase 6 １１２ It may be higher than this. Furthermore, in the embodiment, the carbon content C in the solid solution phase 6b of the first hard phase 6 in the second region far from the surface of the substrate 2 ２１１However, the carbon content C in the core particles 6a of the first hard phase 6 ２１２ It can be even more expensive.

[0050] In such cases, the solid solution formation of the first hard phase 6 in the solid solution phase 6b is facilitated in both the first and second regions. This helps to suppress compositional unevenness in the solid solution phase 6b. Unlike the second hard phase 7, which is composed solely of the solid solution phase, the first hard phase 6 has core particles 6a and solid solution phase 6b with different compositions. Therefore, strain is likely to occur near the boundary between the core particles 6a and the solid solution phase 6b.

[0051] In this case, if there is a large variation in the composition of the solid solution phase 6b, strain is more likely to occur within the solid solution phase 6b. As a result, the synergistic effect of these strains increases the risk of crack formation within the first hard phase 6. However, if the solid solution formation of the first hard phase 6 in the solid solution phase 6b progresses in both the first and second regions, strain is less likely to occur within the solid solution phase 6b. Therefore, crack formation within the first hard phase 6 becomes less likely. Accordingly, according to this embodiment, the durability of the substrate 2 can be further improved.

[0052] Furthermore, in each embodiment, the content C described above １１２ Content C １１１ Ratio C １１１ / C １１２ However, each has the aforementioned content C ２１２ Content C ２１１ Ratio C ２１１ / C ２１２ It may be higher than this. In such cases, the solid solution formation of the first hard phase 6 in the solid solution phase 6b in the first region is particularly facilitated.

[0053] Compared to the second region, the first region is susceptible to localized heavy loads when the cermet member 1 is in use, making it prone to cracking. By suppressing compositional irregularities in the solid solution phase 6b in the crack-prone first region, the risk of crack formation within the first hard phase 6 in the first region is reduced. Therefore, according to this embodiment, the durability of the substrate 2 can be further improved.

[0054] Furthermore, in each embodiment, the ratio C described above １１１ / C １１２ and ratio C ２１１ / C ２１２ However, all of these values ​​may be 1.1 or higher, and even better if they are all 1.33 or higher. This has the effect of increasing the amount of solid solution in the first region. Therefore, according to this embodiment, the durability of the substrate 2 can be further improved.

[0055] Furthermore, in the embodiment, in the first region near the surface of the substrate 2, the titanium content Ti in the outer portion 7b of the second hard phase 7 １２１ However, the titanium content Ti in the inner portion 7a of the second hard phase 7 １２２ It may be lower than this. Furthermore, in the embodiment, in the second region far from the surface of the substrate 2, the titanium content Ti in the outer portion 7b of the second hard phase 7 ２２１ However, the titanium content Ti in the inner portion 7a of the second hard phase 7 ２２２ It can be even more expensive.

[0056] This has the effect of improving the strength of the first region. Therefore, according to this embodiment, the durability of the substrate 2 can be further improved.

[0057] Furthermore, in the embodiment, the tungsten content W in the outer portion 7b of the second hard phase 7 in the first region near the surface of the substrate 2 １２１ However, the tungsten content W in the inner portion 7a of the second hard phase 7 １２２ It may be higher than this. Furthermore, in the embodiment, the tungsten content W in the outer portion 7b of the second hard phase 7 in the second region far from the surface of the substrate 2 ２２１ However, the tungsten content W in the inner portion 7a of the second hard phase 7２２２ It can be lower than that.

[0058] This results in the second hard phase 7 of the first region exhibiting a tendency for high thermal conductivity at high temperatures. The tungsten content W in the outer portion 7b of the second hard phase 7 is １２１ Because this is relatively high, the thermal conductivity at high temperatures can be efficiently increased without excessively increasing the overall tungsten content of the second hard phase 7.

[0059] <Manufacturing Process> Next, an example of the manufacturing process for the cermet member 1 according to the embodiment will be described.

[0060] First, several raw material powders are prepared. Specifically, TiCN powder with an average particle size of 0.1 μm to 1.2 μm is prepared. Note that the average particle size of the TiCN powder may be 0.2 μm to 0.8 μm. Furthermore, the average particle size of the TiCN powder may be 0.5 μm or less. By micronizing the TiCN powder in this way, a first hard phase 6 is easily formed in which core particles 6a, mainly composed of TiCN, are encapsulated in the solid solution phase 6b. In addition, WC powder with an average particle size of 0.1 μm to 2.5 μm is prepared. Also, Cr with an average particle size of 2 μm to 4 μm is prepared. ３ C ２ Prepare the powder.

[0061] Furthermore, the above-mentioned TiCN, WC, and Cr ３ C ２ Prepare a powder of at least one compound from among carbide powders, nitride powders, and carbonitride powders of at least one element from the Group 4, Group 5, and Group 6 elements of the periodic table, excluding the elements in question. Also, prepare a metal W powder and WC with an average particle size of 3 μm to 15 μm. １－ｘ Prepare at least one powder from among the powders (0 < x ≤ 1).

[0062] Next, the various raw material powders described above are mixed to prepare a primary mixed powder. In this preparation process, the above-mentioned metal W powder and WC １－ｘ (0 < x ≤ 1) At least one of the powders may be present in an amount of 1% to 20% by mass relative to the total amount of the primary mixed powder.

[0063] Furthermore, carbon powder may be added to the primary mixed powder, and a predetermined amount of MnCO with an average particle size of 0.5 μm to 5 μm may also be added. ３ Powder may be added.

[0064] In the embodiment, TiCN, WC and Cr ３ C ２ As a powder of at least one compound from carbide powder, nitride powder, and carbonitride powder of at least one element from Group 4, Group 5, and Group 6 of the periodic table excluding the elements mentioned above, the average particle size is 0.1 μm to 3 μm and includes TiC powder, TiN powder, NbC powder, Mo ２ C powder, TaC powder, VC powder, or ZrC powder may be used.

[0065] Next, an organic binder and solvent are added to the primary mixed powder, and the mixture is further ground and mixed using a ball mill, vibration mill, jet mill, or attritor mill to prepare a secondary mixed powder. When using an attritor mill, non-metallic powders are ground down to a smaller particle size, while metal powders tend to be difficult to grind due to their high ductility.

[0066] Next, a predetermined amount of metallic Co powder and metallic Ni powder with an average particle size of 0.5 μm to 5 μm is added to the secondary mixed powder. Then, the mixture is ground and mixed using the known method described above, and further dried to prepare the tertiary mixed powder.

[0067] As described above, TiCN powder with an average particle size of 0.5 μm or less may be prepared as the raw material powder, and the TiCN powder may be pulverized by the following process. Specifically, in the step of preparing the secondary mixed powder and / or the step of preparing the tertiary mixed powder, the primary mixed powder may be pulverized and mixed until the average particle size of the TiCN powder is 0.5 μm or less.

[0068] Next, this tertiary mixed powder is used to form a molded body of a predetermined shape by known molding methods such as press molding, extrusion molding, or injection molding.

[0069] Next, the molded body is fired in a vacuum or inert gas atmosphere. In this embodiment, for example, the substrate 2 with the predetermined structure described above can be produced by firing the molded body in the following steps: (a) Heat from room temperature to 450°C and maintain the 450°C temperature for 0.5 to 2 hours. (b) Heat further from 450°C to a temperature T1 of 1000°C to 1100°C. (c) Heat from firing temperature T1 to firing temperature T2 of 1500°C to 1600°C in a vacuum or in an inert gas atmosphere of 30 Pa to 20000 Pa. (d) Maintain the firing temperature T2 for 0.5 to 2 hours in a vacuum or in an inert gas atmosphere of 30 Pa to 20000 Pa. (e) Cool down to room temperature in a vacuum or in an inert gas atmosphere of 30 Pa to 20000 Pa at a cooling rate of 5°C / min to 40°C / min.

[0070] Subsequently, the cermet member 1 according to the embodiment is completed by forming a coating layer 3 on the surface of the obtained substrate 2. The coating layer 3 may be a so-called hard film, and can be formed, for example, by the PVD method or the CVD method. The coating layer 3 may be a single layer film or a laminated film. Furthermore, the cermet member 1 according to the embodiment does not have to have a coating layer 3.

[0071] <Cutting Tool> Next, the configuration of a cutting tool equipped with the cermet member 1 described above will be explained with reference to Figure 5. Figure 5 is a front view showing an example of a cutting tool 100 according to the embodiment. As shown in Figure 5, the cutting tool 100 according to the embodiment may include a cermet member 1 which is a cutting insert and a holder 70 for fixing the cermet member 1.

[0072] The holder 70 may be a rod-shaped member extending from the tip (upper end in Figure 5) to the rear end (lower end in Figure 5). The holder 70 is made of, for example, steel or cast iron. In particular, it is preferable to use steel, which has high toughness among these materials.

[0073] The holder 70 may have a pocket 73 located at the end on the tip side. The pocket 73 is the part into which the cermet member 1 is mounted, and may have a seating surface that intersects with the rotational direction of the workpiece, and a restraining side surface that is inclined with respect to the seating surface. The seating surface may be provided with a screw hole for screwing in a screw 75, which will be described later.

[0074] The cermet member 1 is located in the pocket 73 of the holder 70 and may be attached to the holder 70 by a screw 75. For example, the screw 75 is inserted into the through hole 21 (see Figure 1) of the cermet member 1, and the tip of the screw 75 is inserted into a screw hole formed in the seating surface of the pocket 73 and screwed in. In this way, the cermet member 1 is attached to the holder 70 such that the cutting edge portion protrudes outward from the holder 70.

[0075] In this embodiment, a cutting tool 100 used in so-called turning operations is illustrated. Examples of turning operations include internal diameter machining, external diameter machining, or grooving operations. However, the cutting tool is not limited to those used in turning operations. For example, a cermet member 1 may be used as a cutting tool for milling operations.

[0076] Examples of cutting tools used in milling include milling cutters such as flat milling cutters, face milling cutters, side milling cutters, or groove milling cutters, and end mills such as single-flute end mills, multi-flute end mills, tapered end mills, or ball end mills.

[0077] The embodiments of this disclosure will be described below in detail. However, this disclosure is not limited to the embodiments shown below.

[0078] A cermet member 1 according to the embodiment was manufactured in accordance with the manufacturing process of the cermet member 1 according to the embodiment described above. Figure 6 is a scanning electron microscope image of a cross-section of the cermet member 1 according to the embodiment.

[0079] As shown in Figure 6, it was confirmed that the substrate 2 of the cermet member 1 according to the embodiment includes a plurality of core particles 6a shown in black, a plurality of solid solution phases 6b and a plurality of second hard phases 7 shown in gray, and a plurality of binding phases 8 shown in grayish-white.

[0080] Furthermore, it was confirmed that even in the substrate 2 of a conventional cermet member 1 (hereinafter also referred to as a reference example) for which scanning electron microscope images are not shown, it contains a plurality of core particles 6a, a plurality of solid solution phases 6b, a plurality of second hard phases 7, and a plurality of binding phases 8.

[0081] Furthermore, the carbon, titanium, and tungsten content in each part of the cermet member 1 of the examples and reference examples was measured using an EDS (energy-dispersive X-ray spectrometer) attached to a STEM (scanning transmission electron microscope). The average values ​​of the results obtained by measuring five locations in the same part are shown in Table 1.

[0082]

[0083] As shown in Table 1, the cermet member 1 according to the embodiment has a content of C １２１ Content C １２２ Higher than, and with a content of C ２２１ Content C ２２２ It was confirmed to be lower than that.

[0084] On the other hand, in the reference example cermet member 1, the content C １２１ Content C １２２ While higher than, the content C ２２１ Content C ２２２ The above has been confirmed.

[0085] Furthermore, in the cermet member 1 according to the embodiment, the content C １１１ Content C １１２ Higher than, and with a content of C ２１１ Content C ２１２ It was confirmed to be higher than that.

[0086] Furthermore, in the cermet member 1 according to the embodiment, the content C １１２ Content C １１１ Ratio C １１１ / C １１２ (= 1.364) is the content C ２１２ Content C ２１１ Ratio C ２１１ / C ２１２ It was confirmed to be higher than (= 1.33).

[0087] Furthermore, in the cermet member 1 according to the embodiment, ratio C １１１ / C １１２ and ratio C ２１１ / C ２１２ However, all of them were confirmed to be 1.33 or higher.

[0088] Furthermore, in the cermet member 1 according to the embodiment, the Ti content １２１ The content Ti １２２ Lower than, and Ti content ２２１ The content Ti ２２２ It was confirmed to be higher than that.

[0089] On the other hand, in the reference example cermet member 1, the Ti content ２２１ The content Ti ２２２ While higher than, the Ti content １２１ The content Ti １２２ The above has been confirmed.

[0090] Furthermore, in the cermet member 1 according to the embodiment, the content W １２１ Content W １２２ Higher than, and with a W content ２２１ Content W ２２２ It was confirmed to be lower than that.

[0091] On the other hand, in the reference example cermet member 1, the content W ２２１ Content W ２２２ While lower than, the content W １２１ Content W １２２ The following has been confirmed:

[0092] Next, the Vickers hardness of the cermet member 1 in the embodiment and the cermet member 1 in the reference example was measured in the first and second regions in accordance with JIS Z 2244:2009. The results are shown in Table 2.

[0093]

[0094] As shown in Table 2, it was confirmed that the Vickers hardness in both the first and second regions of the cermet member 1 according to the embodiment was improved compared to the cermet member 1 of the reference example.

[0095] As described above, in the cermet member 1 according to the embodiment, in the first region, the carbon content C in the outer portion 7b of the second hard phase 7 １２１ is higher than the carbon content C in the inner portion 7a of the second hard phase 7 １２２ , and in the second region, the carbon content C in the outer portion 7b of the second hard phase 7 ２２１ is lower than the carbon content C in the inner portion 7a of the second hard phase 7 ２２２ . Thereby, the durability of the base body 2 can be improved.

[0096] The shape of the cermet member 1 shown in FIG. 1 is merely an example, and does not limit the shape of the cermet member according to the present disclosure. The cermet member according to the present disclosure may have, for example, a rod-shaped main body having a rotation shaft and extending from a tip end to a rear end, a cutting edge located at a first end of the main body, and a groove spirally extending from the cutting edge toward a second end side of the main body.

[0097] Furthermore, in the above embodiment, an example in which the cermet member 1 is applied to a cutting tool has been described, but the field of application of the cermet member according to the present disclosure is not limited to cutting tools.

[0098] Although the present disclosure has been described in detail above, the present disclosure is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the scope of the gist of the present disclosure.

[0099] The embodiment disclosed herein should be considered as illustrative in all respects and not restrictive. Indeed, the above-described embodiment can be embodied in various forms. In addition, the above-described embodiment may be variously omitted, replaced, or modified without departing from the scope and spirit of the appended claims.

[0100] Furthermore, the present technology can have the following configuration. (1) A cermet member comprising a base body having a plurality of hard phases containing a solid solution phase containing Ti, W and C, and a plurality of binder phases that bind between adjacent hard phases, wherein the base body is divided into a first region located at a depth of up to 20 μm from the surface, and a second region located deeper than the first region; the plurality of hard phases include a plurality of first hard phases in which core particles mainly composed of TiCN are enclosed in the solid solution phase, and a plurality of second hard phases composed only of the solid solution phase; the second hard phase is divided into an inner portion located in a range from the center of the second hard phase to (2 / 3)R where R is the radius of the second hard phase, and an outer portion located outside the inner portion; in the first region, the carbon content C in the outer portion of the second hard phase １２１ is higher than the carbon content C in the inner portion of the second hard phase １２２ , and in the second region, the carbon content C in the outer portion of the second hard phase ２２１ is lower than the carbon content C in the inner portion of the second hard phase ２２２ . (2) The cermet member according to (1) above, wherein in the first region, the carbon content C in the solid solution phase of the first hard phase １１１ is higher than the carbon content C in the core particles of the first hard phase １１２ , and in the second region, the carbon content C in the solid solution phase of the first hard phase ２１１ is higher than the carbon content C in the core particles of the first hard phase ２１２ . (3) The cermet member according to (2) above, wherein the ratio C １１２ / C １１１ of the content C １１１ to the content C １１２ is higher than the ratio C ２１２ / C ２１１ of the content C ２１１ to the content C ２１２ . (4) The ratio C １１１ / C １１２ and the ratio C ２１１ / C２１２ (3) The cermet member described above, wherein the ratio C is 1.1 or greater. (5) The ratio C １１１ / C １１２ and the ratio C ２１１ / C ２１２ The cermet member described in (4) above, wherein the ratio is 1.33 or higher in each case. (6) In the first region, the titanium content Ti in the outer portion of the second hard phase １２１ The titanium content Ti in the inner portion of the second hard phase １２２ Lower than and in the second region, the titanium content Ti in the outer portion of the second hard phase ２２１ The titanium content Ti in the inner portion of the second hard phase ２２２ A cermet member according to any one of (1) to (5) above, which is higher than (7) the tungsten content W in the outer portion of the second hard phase in the first region １２１ The tungsten content W in the inner portion of the second hard phase is １２２ Higher than the above, and in the second region, the tungsten content W in the outer portion of the second hard phase ２２１ The tungsten content W in the inner portion of the second hard phase is ２２２ A cermet member according to any one of (1) to (6) above, which is lower than (8) A cutting insert comprising a cermet member according to any one of (1) to (7) above, wherein the base is a cutting insert having a cutting edge. (9) A cutting tool comprising a holder extending from a tip to a rear end and having a pocket located on the side of the tip, and a cutting insert according to (8) located in the pocket.

[0101] 1 Cermet component (an example of a cutting insert) 2 Substrate 3 Coating layer 5 Hard phase 6 First hard phase 6a Core particles 6b Solid solution phase 7 Second hard phase (an example of a solid solution phase) 7a Inner portion 7b Outer portion 8 Bonding phase 10 Interface (an example of a surface) 70 Holder 73 Pocket 100 Cutting tool C Center

Claims

1. A substrate comprising a plurality of hard phases containing a solid solution phase containing Ti, W, and C, and a plurality of bonding phases that bond adjacent hard phases to each other, wherein the substrate is divided into a first region located to a depth of 20 μm from the surface, and a second region located deeper than the first region, wherein the plurality of hard phases comprises a plurality of first hard phases in which core particles mainly composed of TiCN are embedded in the solid solution phase, and a plurality of second hard phases composed only of the solid solution phase, wherein the second hard phase is divided into an inner portion located in the range from the center of the second hard phase to (2 / 3)R, when the radius of the second hard phase is R, and an outer portion located outside the inner portion, wherein in the first region, the carbon content C in the outer portion of the second hard phase １２１ This is the carbon content C in the inner portion of the second hard phase. １２２ Higher than the above, and in the second region, the carbon content C in the outer portion of the second hard phase ２２１ This is the carbon content C in the inner portion of the second hard phase. ２２２ A cermet material with a lower profile.

2. In the first region, the carbon content C in the solid solution phase of the first hard phase. １１１ This is the carbon content C in the core particles of the first hard phase. １１２ Higher than the above, and in the second region, the carbon content C in the solid solution phase of the first hard phase ２１１ This is the carbon content C in the core particles of the first hard phase. ２１２ A cermet member according to claim 1 that is higher than the above.

3. The content ratio C １１２ to said content ratio C １１１ ratio C １１１ / C １１２ is, relative to said content ratio C ２１２ to said content ratio C ２１１ ratio C ２１１ / C ２１２ higher than, the cermet member according to claim 2.

4. Above ratio C １１１ / C １１２ and the ratio C ２１１ / C ２１２ The cermet member according to claim 3, wherein each of the values ​​is 1.1 or greater.

5. Above ratio C １１１ / C １１２ and the ratio C ２１１ / C ２１２ The cermet member according to claim 4, wherein each of these values ​​is 1.33 or greater.

6. In the first region, the titanium content Ti in the outer portion of the second hard phase １２１ The titanium content Ti in the inner portion of the second hard phase １２２ Lower than and in the second region, the titanium content Ti in the outer portion of the second hard phase ２２１ The titanium content Ti in the inner portion of the second hard phase ２２２ A cermet member according to any one of claims 1 to 5, which is higher than the specified value.

7. In the first region, the tungsten content W in the outer portion of the second hard phase. １２１ The tungsten content W in the inner portion of the second hard phase is １２２ Higher than the above, and in the second region, the tungsten content W in the outer portion of the second hard phase ２２１ The tungsten content W in the inner portion of the second hard phase is ２２２ A cermet member according to any one of claims 1 to 6, which is lower than the value specified above.

8. A cutting insert comprising a cermet member according to any one of claims 1 to 7, wherein the base body has a cutting edge.

9. A cutting tool comprising: a holder extending from a tip to a rear end and having a pocket located on the side of the tip; and a cutting insert according to claim 8 located in the pocket.

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