Metal ceramic insert and cutting tool having the metal ceramic insert

Abstract

The metal ceramic insert (1) disclosed in the present invention comprises a first surface (5), a second surface (7), a cutting edge (11) located at least at a portion of the ridgeline between the first surface (5) and the second surface (7), a third surface (9) located on the opposite side of the first surface (5), and a through hole (15) penetrating from the first surface (5) to the third surface (9). The inner wall (17) constituting the through hole (15) comprises a binder phase-enriched layer (19) having a higher binder phase content than the inside of the matrix in at least the central portion. The thickness (T1) of the binder phase-enriched layer (19) in the central portion is thicker than the thickness (T2) of the binder phase-enriched layer (19) at the end portion. The thickness (T1) is greater than 1 μm and less than 20 μm, and the thickness (T2) is greater than 0.2 μm and less than 6 μm. In addition, the first surface (5) is provided with a blade chip breaker (50). The arithmetic mean roughness (Ra) of the blade chip breaker (50) is less than 0.05 μm when the cutoff value is 0.08 mm.

Description

Technical Field

[0001] The present disclosure relates to a cermet insert used in cutting and a cutting tool including the cermet insert. Background Art

[0002] Currently, cermets containing titanium (Ti) as a main component are widely used as base materials for members that require wear resistance, sliding properties, and fracture resistance, such as cutting tools, wear-resistant members, and sliding members.

[0003] For example, Patent Document 1 describes a cutting insert having a through hole for mounting to a tool body and having a surface coated with a titanium carbonitride-based cermet. Patent Document 1 describes a metal seepage layer provided on the inner surface of the through hole for mounting in order to provide an insert with little abnormal damage even in high-load cutting.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-245581 Summary of the invention

[0007] The blade disclosed in the present invention is a metal ceramic blade having a metal ceramic matrix containing hard particles and a binder phase. The metal ceramic blade disclosed in the present invention has a first surface, a second surface, a cutting edge located at least on a portion of the ridgeline between the first surface and the second surface, a third surface located on the opposite side of the first surface, and a through hole that penetrates from the first surface to the third surface. The inner wall constituting the through hole has a binder phase-enriched layer having a higher binder phase content than the inner part of the matrix in at least the central portion. The thickness T1 of the binder phase-enriched layer in the central portion is thicker than the thickness T2 of the binder phase-enriched layer at the end of the inner wall. The thickness T1 is greater than 1 μm and less than 20 μm, and the thickness T2 is greater than 0.2 μm and less than 6 μm. In addition, the first surface is provided with a blade chip breaker. The arithmetic mean roughness Ra of the blade chip breaker is less than 0.05 μm when the cutoff value is 0.08 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a perspective view showing an example of the blade of the present disclosure.

[0009] Figure 2 This is a schematic cross-sectional view showing an example of the insert of the present disclosure.

[0010] Figure 3 It is an enlarged schematic diagram of a cross section of the insert of the present disclosure.

[0011] Figure 4 This is an enlarged schematic diagram of a cross section of another embodiment of the blade disclosed in the present invention.

[0012] Figure 5 This is an enlarged schematic diagram of a cross section of another embodiment of the blade disclosed in the present invention.

[0013] Figure 6 yes Figure 2 A schematic enlarged view of section VI is shown.

[0014] Figure 7 This is a plan view showing an example of the cutting tool of the present disclosure.

[0015] Figure 8 This is an enlarged schematic diagram of a cross section of an insert in the cutting tool of the present disclosure. DETAILED DESCRIPTION

[0016] <Blade>

[0017] Hereinafter, the metal ceramic insert (hereinafter referred to as "insert blade") of the present invention and the cutting tool having the metal ceramic insert are described in detail using the accompanying drawings. However, in the following referenced figures, for the sake of convenience of description, only the main components required in describing the embodiments are simplified. Therefore, the insert of the present invention can have any constituent components not shown in the referenced figures. In addition, the dimensions of the components in the figures do not faithfully show the dimensions of the actual constituent components and the dimensional ratios of the components. These points are also the same in the cutting tools described later.

[0018] It is desirable that a cermet insert used for cutting has less abnormal damage. The present disclosure provides a cermet insert having less abnormal damage and a cutting tool having the cermet insert.

[0019] The blade disclosed in the present invention has a metal ceramic matrix containing hard particles and a binder phase. The hard particles are, for example, TiCN, TiC, TiN, (TiM)CN (M is one or more selected from W, Nb, Ta, Mo, V). The binder phase is mainly composed of iron metals such as Ni or Co. It should be noted that the main component refers to a component that accounts for more than 50% by mass in the constituent components.

[0020] like Figure 1 , 2 As shown, the shape of the blade 1 of the present disclosure may be, for example, a four-sided plate shape. Figure 1 The upper surface, namely the first surface 5, is a so-called rake face. In addition, the insert 1 has a side surface, namely the second surface 7, which is connected to the first surface 5.

[0021] The insert 1 has a third surface 9 which is a lower surface located on the opposite side of the first surface 5. The second surface 7 is connected to the first surface 5 and the third surface 9, respectively.

[0022] The blade 1 of the present disclosure has a cutting edge 11 located at least a portion of the ridgeline where the first face 5 intersects with the second face 7. In other words, the blade 1 of the present disclosure has a cutting edge 11 located at least a portion of the ridgeline where the rake face intersects with the flank face. The cutting edge 11 may have a fourth face continuous with the first face 5 and the second face 7. The fourth face may be a C face (chamfered face) obtained by cutting the corner of the first face 5 and the second face 7 obliquely and in a straight line. In addition, the fourth face may also be an R face (chamfered face) where the corner of the first face 5 and the second face 7 is rounded.

[0023] In the insert 1, the entire outer periphery of the first surface 5 can serve as the cutting edge 11, but the insert 1 is not limited to this structure. For example, only one side of the quadrilateral rake face, in other words, one of the four fourth surfaces may have the cutting edge 11.

[0024] The blade 1 of the present disclosure has a through hole 15 that penetrates the base 3 from the first surface 5 to the third surface 9. Figure 3 As shown, in the inner wall 17 constituting the through hole 15, there is a binder phase-rich layer 19 at least in the central portion 17a. The binder phase-rich layer 19 is a region containing hard particles and a binder phase, and the content of the binder phase is higher than that of the inside of the substrate 3. The inside of the substrate 3 refers to a portion 500 μm or more from the surface of the substrate 3. The binder phase-rich layer 19 does not need to exist on the entire inner wall 17 of the through hole 15, and it only needs to be located at least in the central portion 17a.

[0025] The center portion 17a is the center portion when the through hole 15 is divided into nine equal parts in the depth direction. In addition, the end portions 17b are the end portions when the through hole 15 is divided into nine equal parts in the depth direction.

[0026] like Figure 3 As shown, in the blade 1 of the present disclosure, the thickness T1 of the binder phase-enriched layer 19 of the central portion 17a of the inner wall 17 constituting the through hole 15 is thicker than the thickness T2 of the binder phase-enriched layer 19 of the end portion 17b of the inner wall 17 constituting the through hole 15. The thickness T1 of the binder phase-enriched layer 19 of the central portion 17a and the thickness T2 of the binder phase-enriched layer 19 of the end portion 17b are respectively average values. It is preferred to measure the thickness T1 and the thickness T2 by observing the cross section of the blade 1 using a metal microscope or an electron microscope. It should be noted that the binder phase-enriched layer 19 may not exist in the end portion 17b.

[0027] In the blade 1 of the present disclosure, by having such a structure, the blade 1 is prevented from being abnormally damaged starting from the inner wall 17 to which a large force is applied when the blade 1 is fixed to a handle (not shown).

[0028] The binder phase-rich layer 19 has a lower hardness than the substrate 3 and a higher hardness than the metal-infiltrated layer described in Reference 1. Therefore, the binder phase-rich layer 19 is less deformed than the metal-infiltrated layer.

[0029] Due to the above-mentioned structure, when the blade 1 is fixed to the handle by using a clamp, in the contact between the central portion 17a of the inner wall 17 and the clamp, the local force applied to the base 3 is small due to the suppressed deformation of the bonding phase enriched layer 19 of the central portion 17a, so the blade 1 is not easy to break, and thus it is not easy to cause abnormal damage.

[0030] The size of the blade 1 is not particularly limited. For example, the length of one side of the rake face is set to about 3 to 20 mm. In addition, the thickness of the blade 1 is set to about 1 to 20 mm. Figure 1 In the figure, a quadrilateral blade 1 is shown as an example, but it may also be triangular or disc-shaped.

[0031] In addition, if Figure 4 As shown, the blade 1 of the present disclosure may have an enlarged diameter portion 21 connected to the inner wall 17. There is a step at the boundary between the through hole 15 and the enlarged diameter portion 21. Figure 4 In the example shown, there is no binder phase-rich layer 19 on the inner wall of the expanded diameter portion 21, but the binder phase-rich layer 19 may also exist in the expanded diameter portion 21. In the blade 1 disclosed in the present invention, the expanded diameter portion 21 is not included in the through hole 15. The expanded diameter portion 21 is a so-called countersunk surface. The diameter of the expanded diameter portion 21 is greater than the diameter of the through hole 15 by more than 300 μm.

[0032] The thickness T1 of the binder phase-rich layer 19 in the central portion 17a may be 1 μm or more. Alternatively, the thickness T1 may be 20 μm or less. According to this structure, abnormal damage to the blade 1 is suppressed. The thickness T1 may be 3 μm or more. Alternatively, the thickness T1 may be 10 μm or less.

[0033] The thickness T2 of the binder phase-enriched layer 19 in the end 17b can be 0.2 μm or more. In addition, the thickness T2 can be 6 μm or less. According to this structure, abnormal damage of the blade 1 is suppressed. The thickness T2 can be 0.6 μm or more. The thickness T2 can be 4 μm or less. According to this structure, the local force applied to the substrate 3 is further reduced, so the blade 1 is not easy to break and abnormal damage is further suppressed.

[0034] like Figure 5 As shown, the diameter R1 of the central portion 17a may be larger than the diameter R2 of the end portion 17b. With such a structure, the contact area between the clamping member and the inner wall 17 is increased, and the clamping force is increased.

[0035] The diameter R1 of the center portion 17a may be greater than the diameter R2 of the end portion 17b by 5 μm or more and 30 μm or less. With such a structure, abnormal damage to the insert 1 is suppressed.

[0036] The hardness of the binder phase-enriched layer 19 of the central portion 17a can be 10 GPa or more and 20 GPa or less. According to such a structure, when in contact with the clamping pin, the binder phase-enriched phase 19 is appropriately deformed and the clamping force is increased. For the hardness of the binder phase-enriched layer 19 of the central portion 17a, it is preferred to measure the exposed binder phase-enriched layer 19 in the cross section of the blade 1 using a nanoindentation method.

[0037] The binder phase-enriched layer 19 of the central portion 17a may have a metal layer (not shown) having a greater binder phase content than the binder phase-enriched layer 19 on the through-axis side of the through hole 15. The metal layer does not contain a hard layer but is composed only of metal. With such a structure, the metal layer functions as a buffer material between the clamping member described later and the binder phase-enriched layer 19, so that abnormal damage to the blade 1 is suppressed. The thickness of the metal layer may be greater than 0.3 μm and less than 2 μm.

[0038] The insert 1 may have a coating (not shown) on the binder phase-rich layer 19 of the central portion 17a. The coating may contain, for example, TiCN, TiN, TiCNO, Al 2 O 3 The coating has a portion with a higher hardness than the binder phase-rich layer 19. With such a structure, the wear resistance of the clamping part is increased. The coating can be a single layer or a stacked layer. The coating can be formed by a CVD method or a PVD method.

[0039] Figure 6 yes Figure 2 Schematic enlarged view of section VI shown in FIG. Figure 6 As shown, the insert 1 has a blade chip breaker 50 on the rake surface, that is, the first surface 5. As an example, the blade chip breaker 50 is a recessed portion obtained by recessing the first surface 5. The blade chip breaker 50 has an inclined surface (barrier 51) that slopes downward from the first surface 5 toward the cutting edge 11.

[0040] The blade chip breaker 50 causes the chips of the cut workpiece to curl in the barrier 51, so that the chips can be broken appropriately or discharged in a desired direction. The blade 1 having the blade chip breaker 50 can suppress the biting and winding of the chips. Thus, for example, abnormal damage to the blade 1 caused by the collision of the wound chips with the base 3 can be reduced. It should be noted that the blade chip breaker 50 only needs to have the barrier 51 and is not limited to the shape shown in the figure. For example, the blade chip breaker 50 is not necessarily a recessed portion, but can also be stepped.

[0041] The surface roughness of the blade chip breaker 50 is the arithmetic mean roughness Ra and can be less than 0.05 μm when the cutoff value is 0.08 mm. If the surface roughness of the blade chip breaker 50 is large (in other words, the friction coefficient is large), the cut pieces and chips may be welded to the blade chip breaker 50 depending on the type of the cut piece. As cut pieces that are prone to welding, for example, SCM (chrome-molybdenum steel), SCr420, etc. can be listed. If this welding occurs, a local force is applied to the blade 1 due to the welded cut pieces and chips, and the blade 1 may be damaged. In contrast, by setting the surface roughness of the blade chip breaker 50 to the above-mentioned range, the welding of the cut pieces and chips to the blade chip breaker 50 can be suppressed. As a result, sudden defects and abnormal damage of the blade 1 are suppressed, and the chipping resistance is improved. In other words, the cutting time until chipping occurs is extended.

[0042] The surface roughness of the cutting edge 11, in other words, the surface roughness of the fourth surface on which the cutting edge 11 is arranged is the arithmetic mean roughness Ra and can be less than 0.1 μm when the cutoff value is 0.08 mm. The blade 1 is subjected to greater resistance when it contacts the cut piece (when cutting in). The resistance during cutting in may become an important factor in the defect of the blade 1. In contrast, by setting the surface roughness of the cutting edge 11, which is the position that initially contacts the cut piece, to the above range, the resistance during cutting in can be reduced. As a result, the defect of the blade 1 can be further suppressed, and specifically, the sudden defect generated when cutting into the cut piece can be further suppressed. In addition, the cutting time until the blade 1 is damaged is extended, and the damage resistance is improved.

[0043] The surface roughness of the cutting edge 11 (fourth surface) may be 0.04 μm or less when the cutoff value is 0.08 mm and the arithmetic mean roughness Ra is 0.04 μm or less. In this case, a glossy and well-finished surface is obtained as the cutting edge 11 (fourth surface).

[0044] In the present embodiment, in order to measure the arithmetic mean roughness Ra of the blade chip breaker 50 and the arithmetic mean roughness Ra of the cutting edge 11, in addition to fixing the cutoff value to 0.08 mm, the surface shape of the blade chip breaker 50 and the cutting edge 11 can be measured according to the JIS B0601-2013 standard. The measurement can be performed using, for example, a contact surface roughness measuring instrument using a stylus or a non-contact surface roughness measuring instrument using a laser. When measuring the arithmetic mean roughness Ra of the cutting edge 11, the surface shape in the direction along the cutting edge 11 can be measured. When the first surface 5 is circular and the cutting edge 11 is in an arc shape, the surface shape can be measured on a curve along the cutting edge 11.

[0045] <Manufacturing method of blade>

[0046] The following is a description of a method for manufacturing the blade of the present disclosure.

[0047] The raw material powder used in the production of the blade of the present disclosure is the raw material powder generally used in the production of cermets. The blade of the present disclosure can be obtained by studying the composition of the base body, the firing conditions, and the processing method of the base body.

[0048] The matrix may contain, for example, 40% to 80% by mass of TiCN as hard particles and 6% to 30% by mass of Co as a binder phase. In addition, in order to further improve the properties, the matrix may also contain WC, TaC, NbC, Mo, 2 C, VC, ZrC, etc.

[0049] The raw material having the above composition is formed into a shape having a space that becomes a through hole after firing. Then, for example, firing is performed at a temperature of 1400° C. to 1600° C. The firing atmosphere may be N 2 Under partial pressure atmosphere.

[0050] If N 2 When the partial pressure is set to 1 kPa or more, the thickness of the binder phase-rich layer after firing becomes thicker. In addition, when the average particle diameter d50 of the hard particles used as the raw material is set to 0.7 μm or less, a binder phase-rich layer having a metal layer with a higher binder phase content than the binder phase-rich layer can be obtained on the through-axis (not shown) side of the through hole.

[0051] It should be noted that, during the above-mentioned forming, if the forming pressure is high, the deformation during firing can be suppressed. On the other hand, if the forming pressure is reduced during forming, the diameter R1 of the central part of the inner wall is likely to be larger than the diameter R2 of the end part. Since the relationship between the forming pressure and the deformation varies depending on the composition or firing temperature, various combinations can be used for adjustment.

[0052] For example, after firing, a rotating brush can be inserted into the through hole from both ends to grind the inner wall of the through hole so that the thickness T1 of the binder phase-rich layer in the center is thicker than the thickness T2 of the binder phase-rich layer at the ends, thereby obtaining the blade of the present disclosure. It should be noted that the brush can be inserted from both sides of the through hole or from one side in two portions.

[0053] Then, a coating layer (not shown) may be provided as required. The coating layer may be a so-called hard film, and may be formed by, for example, a PVD method or a CVD method. The coating film may be a single layer or a laminated film.

[0054] As the coating film, for example, TiN, TiCN, TiCNO, Al2 O 3 , TiAlN, etc. Coatings made of materials other than those mentioned above may also be used.

[0055] Furthermore, after firing, there may be a binder phase-rich layer in a region other than the through-hole, such as the first surface, the second surface, or the third surface. However, the binder phase-rich layer may be removed as necessary.

[0056] The surface roughness of the blade chip breaker can be adjusted, for example, by sandblasting the surface of the substrate. Specifically, sandblasting is a processing method in which a mixture (slurry) obtained by mixing a solution mixed with ceramic abrasives and compressed air collides with the surface of the substrate. Examples of ceramic abrasives include aluminum oxide. The average particle size of the ceramic abrasives may be less than 10 μm. If the average particle size of the ceramic abrasives exceeds 10 μm, the surface roughness of the substrate is relatively rough, and may be a surface roughness outside the above range.

[0057] The surface roughness of the cutting edge can be adjusted by grinding only the cutting edge using a grinding method such as a brush, an elastic grinder, or sandblasting. As a grinding method, brush grinding can be performed. At this time, a brush that is easily bent, such as a pig hair brush, and a grinding liquid containing diamond powder and lubricating oil mixed with particles having an average particle size of less than 4 μm and preferably an average particle size of more than 0.5 μm and less than 2.5 μm can also be used. Next, the protrusion of the bristles in the brush grinding is set to more than 0.5 cm and less than 5 cm, and a grinding liquid containing diamond powder and lubricating oil mixed with particles having an average particle size of more than 0.5 μm and less than 2.5 μm is used for brush grinding. At this time, a blade is set to a shell having a recess of the same shape as that of the blade for processing. At this time, the cutting edge height becomes the same height as the upper surface of the shell, and the gap between the shell and the outer periphery of the blade is within 0.5 mm. In addition, the front end of the bristles can also be set in a manner that becomes the same height as the upper surface of the shell for grinding processing.

[0058] Thus, only the blade chip breaker can be ground. Therefore, the surface roughness of the blade chip breaker can be adjusted to a desired range while the surface roughness of the cutting edge is set to a desired range. In addition, the surface roughness of the blade chip breaker can be adjusted by performing vapor deposition on the cutting edge and using a brush, an elastic grinder, sandblasting, or other grinding methods for the portion where the blade chip breaker is formed.

[0059] Next, the surface roughness of the cutting edge is adjusted by grinding only the cutting edge using grinding methods such as a brush, an elastic grinder, and sandblasting. As a grinding method, brush grinding can also be performed. At this time, it is also possible to set the protruding amount of the bristles in the brush grinding to more than 0.5cm and less than 5cm, and preferably to more than 2.5cm and less than 3.5cm, and use a diamond powder mixed with particles with an average particle size of less than 4μm and preferably with an average particle size of more than 0.5μm and less than 2.5μm and a grinding fluid of lubricating oil. Thus, the surface roughness of the cutting edge can be adjusted to a desired range while the surface roughness of the cutting edge can be set to a desired range. In addition, the blade chip breaker can also be vapor-deposited and the surface roughness of the cutting edge can be adjusted using grinding methods such as a brush, an elastic grinder, and sandblasting for the portion forming the cutting edge. In addition, the blade chip breaker can also be vapor-deposited and the surface roughness of the cutting edge can be adjusted using grinding methods such as a brush, an elastic grinder, and sandblasting for the portion forming the cutting edge.

[0060] <Cutting tools>

[0061] Next, the cutting tool of the present disclosure will be described using the drawings.

[0062] like Figure 7 As shown, the cutting tool 101 of the present disclosure is, for example, Figure 7 ) toward the second end ( Figure 7 The rod-shaped body extends from the lower end of the Figure 7 As shown, the cutting tool 101 includes a shank 105 having a groove 103 at a first end side (front end side), and the above-mentioned insert 1 located at the groove 103 .

[0063] In addition, if Figure 8 As shown, the clamping member 107 is inserted into the through hole 15 of the blade 1 (refer to Figure 1 ).exist Figure 8 In the example shown, the clamping member 107 is connected to the binder phase-rich layer 19 (see Figure 2 ) is in direct or indirect contact with the blade 1. It should be noted that the indirect contact between the clamping member 107 and the bonding phase enriched layer 19 refers to the state in which a metal layer or a coating exists between the bonding phase enriched layer 19 and the clamping member 107. The bonding phase enriched layer 19 in contact with the clamping member 107 is more easily deformed than the substrate 3, so it is not easy to apply a local strong force to the blade 1. In addition, if there is a bonding phase enriched layer 19, the contact area between the clamping member 107 and the bonding phase enriched layer 19 is large, so the blade 1 is not easy to move in the tool groove during cutting. Complementing such an effect, the blade 1 disclosed in the present invention is not easy to be abnormally damaged. Since the cutting tool 101 is provided with the blade 1, stable cutting processing can be performed for a long time.

[0064] The knife groove 103 is a portion for the blade 1 to be mounted, and has a seating surface parallel to the lower surface of the knife handle 105 and a limiting side surface inclined relative to the seating surface. In addition, the knife groove 103 is open at the first end side of the knife handle 105.

[0065] The blade 1 is located in the knife groove 103. At this time, the lower surface of the blade 1 may directly contact the knife groove 103, or a sheet (not shown) may be sandwiched between the blade 1 and the knife groove 103.

[0066] The blade 1 is mounted on the handle 105 in such a manner that at least a portion of the portion used as the cutting edge 11 at the ridgeline where the rake face and the flank face intersect protrudes outward from the handle 105. In the present embodiment, the blade 1 is mounted on the handle 105 by a fixing screw 107. That is, the fixing screw 107 is inserted into the through hole 15 of the blade 1, the front end of the fixing screw 107 is inserted into a threaded hole (not shown) formed in the blade groove 103, and the threaded portions are screwed together, thereby mounting the blade 1 on the handle 105.

[0067] Steel, cast iron, etc. can be used as the material of the shank 105. Among these members, steel with high toughness can be used.

[0068] In this embodiment, a cutting tool 101 used in so-called turning processing is illustrated. As turning processing, for example, inner diameter processing, outer diameter processing, slotting processing, and end surface processing can be listed. It should be noted that the cutting tool 101 is not limited to the cutting tool used in turning processing. For example, the insert 1 of the above-mentioned embodiment can also be used for the cutting tool 101 used in milling processing.

[0069] Example

[0070] Hereinafter, the blade of the present disclosure will be described.

[0071] The matrix is ​​produced in the following manner. After adding a binder to a raw material powder containing 40 mass % TiCN, 12 mass % TiN, 20 mass % WC, 8 mass % NbC, 20 mass % Co and other inevitable carbides, it is adjusted to a desired shape by stamping to produce a molded body in the shape of a tool with a through hole. These raw material powders are raw material powders commonly used in the manufacture of metal ceramics. The composition of the matrix disclosed in the present invention is also not special. Then, after removing the binder component, it is sintered under a nitrogen atmosphere of 3kPa at a temperature of 1530°C for 1 hour to obtain a blade having a bonding phase enriched layer with a metal layer on the inner wall of the through hole.

[0072] Then, the inner wall of the through hole was polished with a brush to produce a blade having the structure shown in Table 1. It should be noted that the portion without a binder phase-rich layer or with a thin binder phase-rich layer is the portion obtained by prolonging the brush polishing time.

[0073] [Table 1]

[0074] (Table 1)

[0075]

[0076] Among the samples No. 1 to 23 shown in Table 1, Samples No. 1, 2, 3, 4, 11, 12, 13, 14, 15, 19, 20, 22, and 23 are comparative examples, and Samples No. 5 to 10, 16 to 18, and 21 are examples.

[0077] It should be noted that the first surface, the second surface and the third surface of any blade are all sandblasted to remove the binder phase-rich layer.

[0078] Brush polishing is performed by applying a polishing liquid mixed with 0.1 to 3 μm diamond powder and lubricating oil to a pig hair brush, and rotating the pig hair brush while polishing the through hole, the blade chip breaker, and the cutting edge.

[0079] The thickness of the center and end portions of the binder phase-rich layer, the diameter R1 of the center portion, and the diameter R2 of the end portions were measured using a cross section obtained by cutting the substrate along a plane including the through-axis in the thickness direction.

[0080] Furthermore, when the hardness of the interior of the matrix and the hardness of the binder phase-rich layer were measured using a cross section of the insert, the hardness of the binder phase-rich layer was lower than the hardness of the interior of the matrix.

[0081] The obtained blade was placed in the blade groove of the tool holder, and a clamp was inserted into the through hole of the blade to fix the blade with the clamp. Then, a cutting test was performed under the following conditions.

[0082] <Cutting test>

[0083] Cutting material: SCr420

[0084] Cutting speed: 150m / min

[0085] Feed: 0.15mm / rev

[0086] Cutting amount: 0.5mm

[0087] Cutting state: wet

[0088] Evaluation method: The cutting time until chipping occurred was evaluated.

[0089] For samples No. 1, 2, 3, 4, 11, 12, 13, 14, 15, 19, 20, 22, and 23 that do not have the structure of the blade disclosed in the present invention, the cutting time until the chipping occurs is short and abnormal damage occurs. For the blade disclosed in the present invention, the blade is well held in the shank and abnormal damage is suppressed. In addition, the cutting time until the chipping occurs is prolonged and the surface roughness of the processed workpiece is also good.

[0090] Based on the above results, the surface roughness Ra of the insert chip breaker is preferably 0.05 μm or less. In addition, the surface roughness Ra of the cutting edge may be 0.1 μm or less, and more preferably 0.04 μm or less.

[0091] The cermet insert of the present disclosure and the cutting tool including the cermet insert described above are merely examples, and may have different structures without departing from the gist of the present application.

[0092] Description of Reference Numerals

[0093] 1. Blade

[0094] 3. Matrix

[0095] 5···Page 1

[0096] 7···Side 2

[0097] 9···Side 3

[0098] 10···Side 4

[0099] 11···Cutting edge

[0100] 15···Through hole

[0101] 17···Inner wall

[0102] 17a··Central

[0103] 17b··End

[0104] 19···Binder phase-rich layer

[0105] 21···Expanded diameter

[0106] T1···Thickness of the binder phase-rich layer in the central part

[0107] T2···Thickness of the binder phase-rich layer at the end

[0108] R1···Diameter of the center

[0109] R2···Diameter of the end

[0110] 101···Cutting tools

[0111] 103···Knife groove

[0112] 105···Knife handle

[0113] 107···Clamping piece.

Claims

1. A metal ceramic insert having a metal ceramic matrix containing hard particles and a binder phase, in, The metal ceramic blade has: First side; Second side; a cutting edge located at least at a portion of an edge line between the first surface and the second surface; a third surface located on the opposite side of the first surface; as well as a through hole extending from the first surface to the third surface, The inner wall constituting the through hole has a binder phase-rich layer having a higher content of the binder phase than the inner part of the matrix at least in the central part. The thickness T1 of the binder phase-rich layer in the central portion is thicker than the thickness T2 of the binder phase-rich layer at the end portion of the inner wall. The thickness T1 is greater than or equal to 1 μm and less than or equal to 20 μm. The thickness T2 is greater than or equal to 0.2 μm and less than or equal to 6 μm. The first surface is provided with a blade chip breaker, The arithmetic mean roughness Ra of the blade chip breaker is 0.05 μm or less when the cutoff value is 0.08 mm.

2. The metal ceramic blade according to claim 1, in, The cutting edge has a fourth surface continuous with the first surface and the second surface, The arithmetic mean roughness Ra of the fourth surface is 0.1 μm or less when the cutoff value is 0.08 mm.

3. The metal ceramic blade according to claim 2, in, The arithmetic mean roughness Ra of the fourth surface is 0.04 μm or less when the cutoff value is 0.08 mm.

4. The cermet blade according to any one of claims 1 to 3, in, The diameter R1 of the central portion is larger than the diameter R2 of the end portions.

5. The metal ceramic blade according to claim 4, in, The diameter R1 is greater than the diameter R2 by 5 μm or more and 30 μm or less.

6. The cermet blade according to any one of claims 1 to 3, in, The binder phase-rich layer in the central portion has a hardness of 10 GPa or more and 20 GPa or less.

7. The cermet blade according to any one of claims 1 to 3, in, The binder phase-rich layer in the central portion includes a metal layer having a larger binder phase content than that in the binder phase-rich layer on the through-axis side of the through-hole.

8. The cermet blade according to any one of claims 1 to 3, in, The cermet insert includes a coating layer on the binder phase-rich layer in the central portion, and the coating layer includes a portion having a higher hardness than the binder phase-rich layer.

9. A cutting tool, in, The cutting tool has: A knife handle having a length from a first end to a second end and having a knife groove located on a side of the first end; The metal ceramic insert according to any one of claims 1 to 8, which is located in the blade groove; as well as A clamp is inserted into the through hole of the cermet insert.

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