Diamond Tools

Abstract

The diamond member has a rake face and a flank. The ridge between the rake face and the flank forms a cutting edge. The arithmetic mean roughness of the rake face is 0.1 μm or more and 1.0 μm or less. The diamond member is measured for energy loss associated with the excitation of K-shell electrons of carbon by electron energy loss spectroscopy using a transmission electron microscope. The energy loss is used to measure the π bond originating from the carbon π bond in the graphite phase. * The intensity of the peaks and the σ due to the σ bond of carbon in the graphite phase and the diamond phase are * The peak intensity is calculated. * The peak intensity is σ * Divide the value by the peak intensity to obtain I π* / I σ* When the diamond material on the surface of the rake face is π* / I σ* is between 0.2 and 2.

Description

[Technical Field]

[0001] The present disclosure relates to diamond tools. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2004-223648 (Patent Document 1) describes a hard sintered cutting tool having a surface roughness of the tool rake face in the range of Rz: 1 to 15 μm. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-223648 Summary of the Invention

[0004] The diamond tool according to the present disclosure comprises a diamond member. The diamond member includes a rake face portion and a flank face. The flank face is continuous with the rake face portion. The ridge between the rake face portion and the flank face forms a cutting edge. The arithmetic mean roughness of the rake face portion is 0.1 μm or more and 1.0 μm or less. The diamond member includes a diamond phase having a diamond crystal structure and a graphite phase having a graphite crystal structure. The energy loss associated with the excitation of K-shell electrons of carbon is measured for the diamond member by electron energy loss spectroscopy using a transmission electron microscope. The energy loss is used to measure the π bonds originating from the carbon π bonds in the graphite phase. * The intensity of the peaks and the σ due to the σ bond of carbon in the graphite phase and the diamond phase are * The peak intensity is calculated. * The peak intensity is σ * Divide the value by the peak intensity to obtain I π* / I σ* When the diamond material on the surface of the rake face is π* / I σ* is between 0.2 and 2. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a cross-sectional view showing the configuration of a diamond tool according to a first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a schematic diagram illustrating a method for measuring Iπ* / Iσ* using TEM-EELS. [Figure 5] FIG. 5 is a flow chart schematically showing the method for manufacturing a diamond tool according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a process of performing laser processing on a diamond member. [Figure 7] FIG. 7 is a cross-sectional view showing a configuration of a diamond tool according to a modified example of the first embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing the configuration of a diamond tool according to the second embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view taken along line VIII-VIII in FIG. [Figure 10] FIG. 10 is a cross-sectional view illustrating a method for manufacturing a diamond tool according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] [Problem to be solved by this disclosure] When cutting a workpiece using a diamond tool, chips may adhere to the rake face or become stuck on the rake face. In this case, the diamond tool is prone to chipping. Therefore, it has been difficult to improve the tool life of the diamond tool.

[0007] An object of the present disclosure is to provide a diamond tool that can improve the tool life.

[0008] [Effects of this disclosure] According to the present disclosure, a diamond tool capable of improving tool life can be provided.

[0009] [Outline of the embodiment] First, an overview of the embodiment of the present disclosure will be described.

[0010] (1) A diamond tool according to the present disclosure has a diamond member. The diamond member has a rake face portion and a flank face. The flank face is continuous with the rake face portion. The ridge between the rake face portion and the flank face forms a cutting edge. The arithmetic mean roughness of the rake face portion is 0.1 μm or more and 1.0 μm or less. The diamond member has a diamond phase consisting of a diamond crystal structure and a graphite phase consisting of a graphite crystal structure. The energy loss associated with the excitation of K-shell electrons of carbon is measured for the diamond member by electron energy loss spectroscopy using a transmission electron microscope. The energy loss is used to measure the π bonds originating from the carbon π bonds in the graphite phase. * The intensity of the peaks and the σ due to the σ bond of carbon in the graphite phase and the diamond phase are * The peak intensity is calculated. * The peak intensity is σ * Divide the value by the peak intensity to obtain I π* / I σ* When the diamond material on the surface of the rake face is π* / I σ* is between 0.2 and 2.

[0011] This reduces the frictional force generated between the rake face and the chips, thereby improving the tool life of the diamond tool.

[0012] (2) According to the diamond tool of (1) above, the arithmetic mean roughness of the flank may be smaller than the arithmetic mean roughness of the rake face, thereby preventing the surface roughness of the workpiece from deteriorating.

[0013] (3) The diamond tool according to (1) or (2) above may further include a main body and a brazing material. The brazing material may bond the diamond member and the main body. The diamond member may be formed of polycrystalline sintered diamond. The I of the diamond member at a position 1.0 μm from the surface of the rake face in the normal direction of the rake face may be π* / I σ* may be 0.001 or more and 0.1 or less, whereby chipping of the diamond member can be prevented.

[0014] (4) According to the diamond tool according to any one of (1) to (3) above, the I of the diamond member on the surface of the flank π* / I σ* may be 0.2 or more and 2 or less. This makes it possible to reduce the friction force between the workpiece and the flank when machining the workpiece.

[0015] (5) According to the diamond tool according to any one of (1) to (4) above, the I of the diamond member at a position 0.5 μm from the surface of the rake face in the normal direction of the rake face π* / I σ* may be 0.2 or more and 2 or less. I of the diamond member at a position 0.5 μm from the surface of the flank in the normal direction of the flank π* / I σ* may be 0.001 or more and 0.1 or less, whereby it is possible to prevent the strength of the diamond member in the vicinity of the flank face from being excessively reduced.

[0016] [Details of the embodiment] Hereinafter, details of embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated.

[0017] (First embodiment) First, the configuration of the diamond tool 10 according to the first embodiment will be described.

[0018] Fig. 1 is a cross-sectional view showing the configuration of a diamond tool 10 according to a first embodiment. As shown in Fig. 1, the diamond tool 10 mainly includes a diamond member 4, a main body 8, and a brazing material 7. The diamond member 4 forms a cutting edge 3. The brazing material 7 joins the diamond member 4 and the main body 8 together.

[0019] The diamond tool 10 is a cutting tool such as a drill, an end mill, an indexable cutting tip for a drill, an indexable cutting tip for an end mill, an indexable cutting tip for a milling cutter, an indexable cutting tip for a turning cutter, a reamer, a metal saw, a gear cutting tool, a tap, etc. The diamond tool 10 may be a wear-resistant tool such as a die, a scriber, a scribing wheel, or a dresser, or may be a grinding tool such as a grinding wheel.

[0020] As shown in FIG. 1 , the diamond member 4 has a rake face 1, a flank face 2, and a bonded surface 30. The rake face 1 is a surface that scoops out chips cut from a workpiece (not shown) during cutting. The flank face 2 is continuous with the rake face 1. The flank face 2 is a surface that faces the workpiece surface during cutting. At the bonded surface 30, the diamond member 4 is in contact with the brazing material 7.

[0021] The rake face 1 has a first rake face portion 11 and a second rake face portion 12. The first rake face portion 11 is continuous with the flank face 2. The ridge line between the first rake face portion 11 and the flank face 2 forms a cutting edge 3. The second rake face portion 12 is continuous with the first rake face portion 11. The second rake face portion 12 is spaced apart from the flank face 2.

[0022] The normal direction of the first rake face portion 11 is defined as a first direction 101. The first direction 101 is perpendicular to the first rake face portion 11 and is a direction from the first rake face portion 11 toward the inside of the diamond member 4. The cross section shown in FIG. 1 is a cross section perpendicular to the tangent of the cutting edge 3 when viewed in the first direction 101.

[0023] The width H of the first rake face 11 is, for example, 0.1 mm or more and 15 mm or less. In a cross section perpendicular to the tangent line of the cutting edge 3 when viewed in the first direction 101, the width H of the first rake face 11 is the linear distance between the cutting edge 3 and a connection point 19 between the first rake face 11 and the second rake face 12.

[0024] As shown in FIG. 1 , the flank 2 has a first flank portion 21 and a second flank portion 22. The first flank portion 21 is continuous with the first rake face portion 11. The ridgeline between the first flank portion 21 and the first rake face portion 11 forms the cutting edge 3. The second flank portion 22 is continuous with the first flank portion 21. The second flank portion 22 is spaced apart from the first rake face portion 11.

[0025] The normal direction of the flank 2 is set to be a second direction 102. The second direction 102 is perpendicular to the flank 2 and is a direction from the flank 2 toward the inside of the diamond member 4. The second direction 102 is the same as the normal direction of the second flank portion 22.

[0026] The bonded surface 30 has, for example, a first bonded surface portion 31 and a second bonded surface portion 32. The first bonded surface portion 31 is continuous with the flank 2. In the diamond member 4, the first bonded surface portion 31 is located opposite the rake face 1. The second bonded surface portion 32 is continuous with both the rake face 1 and the first bonded surface portion 31. The second bonded surface portion 32 may be perpendicular to the first bonded surface portion 31. In the diamond member 4, the second bonded surface portion 32 is located opposite the flank 2.

[0027] The diamond member 4 is formed of, for example, polycrystalline sintered diamond. From another perspective, the diamond member 4 includes, for example, a plurality of diamond particles.

[0028] The polycrystalline sintered diamond forming the diamond member 4 may contain, for example, a binder. The binder bonds a plurality of diamond particles. The binder contains, for example, at least one element selected from iron (Fe), cobalt (Co), and nickel (Ni), or any of their mutual solid solutions. Specifically, the binder is formed from, for example, Co, Co-Fe, Ni-Co, etc. Hereinafter, polycrystalline sintered diamond containing a binder will also be referred to as PCD (Poly-Crystalline Diamond).

[0029] The percentage of the volume of the diamond particles in the PCD divided by the total volume of the PCD is, for example, 80% to 99%. In other words, the percentage of the sum of the volume of the binder and the volume of the unavoidable impurities in the PCD divided by the total volume of the PCD is, for example, 1% to 20%.

[0030] The polycrystalline sintered diamond forming the diamond member 4 may not contain a binder. Hereinafter, polycrystalline sintered diamond that does not contain a binder will also be referred to as binderless polycrystalline diamond or BLPCD. BLPCD is a polycrystalline sintered diamond in which multiple diamond particles are bonded to each other without the aid of a binder (binding material).

[0031] In a BLPCD, the percentage of the volume of carbon divided by the volume of the BLPCD excluding impurity elements is substantially 100%. In a BLPCD, the value of the mass of the impurity elements divided by the total mass of the BLPCD (the impurity element content) is, for example, 5% or less. In a BLPCD, the impurity element content may be 0%.

[0032] The impurity element is, for example, one or more metal elements selected from the group consisting of rare earth elements, alkaline earth metals, cobalt (Co), iron (Fe), nickel (Ni), titanium (Ti), tungsten (W), tantalum (Ta), chromium (Cr), and vanadium (V). The impurity element may also be, for example, one or more nonmetallic or semimetallic elements selected from the group consisting of nitrogen, oxygen, boron, silicon, and hydrogen. The type and content of the impurity element can be measured, for example, using secondary ion mass spectrometry (SIMS).

[0033] D of multiple diamond particles forming BLPCD or PCD 50 The average particle size is not particularly limited, but may be, for example, 0.005 μm or more and 100 μm or less. 50 As the value of σ decreases, the hardness of the BLPCD or PCD tends to increase.

[0034] D of diamond particles forming BLPCD or PCD 50 can be measured using a scanning electron microscope (SEM) and image analysis software. The SEM can be, for example, a JSM-7800F manufactured by JEOL Ltd. The image analysis software can be, for example, WinROOF manufactured by Mitani Shoji Co., Ltd.

[0035] Specifically, first, a BLPCD or PCD sample is prepared from the diamond member 4. The surface of the sample is mirror-polished. Next, a backscattered electron image of the mirror-polished surface of the sample is observed using an SEM at a magnification of 5,000 times or more and 20,000 times or less. This allows multiple diamond particles to be identified in the backscattered electron image.

[0036] The circular equivalent diameter of each of the identified multiple diamond particles is calculated using image analysis software. For example, by observing five or more fields of view, the circular equivalent diameters of 100 or more diamond particles can be calculated. Next, all the calculated circular equivalent diameters are sorted in ascending order from minimum to maximum to determine the cumulative distribution. The particle diameter at which the cumulative area is 50% in the cumulative distribution is called D 50 The circle equivalent diameter means the diameter of a circle having the same area as the measured area of ​​the diamond particle.

[0037] The diamond member 4 has a diamond phase having a diamond crystal structure and a graphite phase having a graphite crystal structure. Specifically, the diamond particles forming the diamond member 4 have a diamond phase and a graphite phase.

[0038] As shown in FIG. 1, the diamond member 4 has a graphite-altered layer 6 and a diamond portion 5. The graphite-altered layer 6 is continuous with the diamond portion 5. The graphite-altered layer 6 is a portion where the graphite phase is present in a relatively large proportion. The diamond portion 5 is a portion where the graphite phase is present in a relatively small proportion. The graphite phase presence ratio in the diamond member 4 will be described in detail later.

[0039] The first rake face portion 11 is formed by the graphite-affected layer 6. The second rake face portion 12 is formed by the diamond portion 5. The first flank face portion 21 is formed by the graphite-affected layer 6. The second flank face portion 22 is formed by the diamond portion 5.

[0040] The main body 8 is formed of, for example, either a cemented carbide or a cermet. The cemented carbide is, for example, mainly composed of tungsten carbide (WC) and also contains cobalt (Co). The cemented carbide may contain carbides, nitrides, or carbonitrides of titanium (Ti), tantalum (Ta), and niobium (Nb). The structure of the cemented carbide may contain free carbon and abnormal phases called η phase or ε phase.

[0041] When the main body 8 is made of a cermet, the main body 8 is made of a cermet containing, for example, titanium carbonitride (TiCN) as a main component. The main body 8 may also be made of a cermet containing, for example, titanium carbide (TiC) or titanium nitride (TiN) as a main component. When the main body 8 is made of the above-mentioned cemented carbide or cermet, the hardness and strength of the main body 8 at high temperatures can be sufficiently improved.

[0042] The surface of the main body 8 may be modified. Specifically, for example, when the main body 8 is made of cemented carbide, a de-β layer may be formed on the surface of the main body 8. When the main body 8 is made of cermet, a surface-hardened layer may be formed on the surface of the main body 8. The main body 8 may be made of high-speed steel, or may be made of ceramics such as titanium carbide, silicon carbide, silicon nitride, aluminum nitride, and aluminum oxide.

[0043] When the diamond tool 10 is a drill or an end mill, the main body 8 may be referred to as a shank. When the diamond tool 10 is an indexable cutting tip, the main body 8 may or may not have a chip breaker.

[0044] The brazing filler metal 7 is located between the diamond member 4 and the main body 8. The brazing filler metal 7 covers the joined surface 30. The brazing filler metal 7 is formed of, for example, silver brazing. From another perspective, the brazing filler metal 7 contains, for example, silver (Ag) and copper (Cu).

[0045] <Surface roughness> Next, the surface roughness of each of the rake face 1 and the flank 2 will be described. The arithmetic mean roughness (Ra) of the first rake face portion 11 is 0.1 μm or more and 1.0 μm or less. The Ra of the first rake face portion 11 may be, for example, 0.2 μm or more and 0.9 μm or less, or 0.3 μm or more and 0.8 μm or less.

[0046] The arithmetic mean roughness (Ra) is a surface texture parameter defined in JIS (Japanese Industrial Standards) B0601:2013. The Ra of the second rake face portion 12 is smaller than the Ra of the first rake face portion 11. The Ra of the second rake face portion 12 is, for example, less than 0.1 μm.

[0047] The Ra of the flank 2 is smaller than the Ra of the first flank portion 11. Specifically, the Ra of each of the first flank portion 21 and the second flank portion 22 is smaller than the Ra of the first flank portion 11. The Ra of the second flank portion 22 is, for example, smaller than the Ra of the first flank portion 21. The Ra of the flank 2 is, for example, less than 0.1 μm. A laser microscope, for example, an OPTELICS HYBRID manufactured by Lasertec Corporation, is used to measure Ra.

[0048] <The ratio of graphite phase in diamond material (I π* / I σ* )> Next, the proportion of the graphite phase in the diamond member 4 will be described.

[0049] In measuring the abundance ratio of the graphite phase in the diamond member 4, electron energy loss spectroscopy (TEM-EELS) using a transmission electron microscope is used. Specifically, the energy loss associated with the excitation of K-shell electrons of carbon is measured for the diamond member 4 using TEM-EELS. The measured energy loss is used to determine the π bond originating from the carbon π bond in the graphite phase. * Peak intensity (Iπ* ) and σ originating from the σ bond of carbon in the graphite and diamond phases, respectively. * Peak intensity (I σ* ) is obtained. In the following, π * The peak intensity is σ * Divided by the peak intensity, I π* / I σ* It is said that. π* / I σ* The smaller the value, the smaller the proportion of graphite phase at the measured point. π* / I σ* The larger the value, the greater the proportion of the graphite phase present at the measured point.

[0050] Next, I π* / I σ* The measurement position of is explained. FIG. 2 is a cross-sectional schematic view taken along line II-II in FIG. 1. The cross section shown in FIG. 2 is a cross section parallel to the normal direction of the first rake face portion 11. From another perspective, the cross section shown in FIG. 2 is a cross section perpendicular to the first rake face portion 11.

[0051] As shown in FIG. 2, the position of the surface of the first rake face portion 11 is defined as a first position P1. The first position P1 overlaps with the first rake face portion 11. From another perspective, in the first direction 101, the distance between the first position P1 and the first rake face portion 11 is 0 μm. In the first direction 101, a position that is 0.5 μm away from the first rake face portion 11 is defined as a second position P2. In the first direction 101, a position that is 1.0 μm away from the first rake face portion 11 is defined as a third position P3. At each of the first position P1, the second position P2, and the third position P3, the above-mentioned I π* / I σ* is measured.

[0052] Fig. 3 is a cross-sectional schematic view taken along line III-III in Fig. 1. The cross section shown in Fig. 3 is parallel to the normal direction of the second flank portion 22. From another perspective, the cross section shown in Fig. 3 is perpendicular to the second flank portion 22.

[0053] 3, the position of the surface of the second flank portion 22 is set to a fourth position P4. From another perspective, the fourth position P4 is the position of the surface of the flank 2. The fourth position P4 overlaps with the second flank portion 22. From another perspective, the distance between the fourth position P4 and the second flank portion 22 in the second direction 102 is 0 μm.

[0054] A position that is 0.5 μm away from the second flank portion 22 in the second direction 102 is defined as a fifth position P5. From another perspective, the fifth position P5 is a position that is 0.5 μm away from the flank 2 in the second direction 102. A position that is 1.0 μm away from the second flank portion 22 in the second direction 102 is defined as a sixth position P6. From another perspective, the sixth position P6 is a position that is 1.0 μm away from the flank 2 in the second direction 102. At each of the fourth position P4, the fifth position P5, and the sixth position P6, the above-mentioned I π* / I σ* is measured.

[0055] Next, using TEM-EELS, I π* / I σ* A method for measuring this will be described. First, the diamond member 4 is cut along a plane parallel to the first direction 101 using an argon ion slicer. This produces a first sample 9 having a thickness of 3 nm or more and 100 nm or less. The first sample 9 is observed using a transmission electron microscope (TEM) at a magnification of 100,000 times or more and 1,000,000 times or less. This produces a cross-sectional transmission image of the diamond particles contained in the first sample 9. In the cross-sectional transmission image, the first position P1, the second position P2, and the third position P3 are each identified. As the TEM, for example, a JEM-2100F / Cs manufactured by JEOL Ltd. is used.

[0056] Figure 4 shows the I π* / I σ*4 is a schematic diagram illustrating a measurement method for the first sample 9. As shown in FIG. 4, an electron beam 93 is irradiated onto a cross section 91 of the first sample 9 along arrow A. Arrow A is perpendicular to the cross section 91. The electron beam 93 excites electrons in the first sample 9. As a result, part of the energy of the electron beam 93 is lost. The electron beam 93 that has passed through the first sample 9 is dispersed by a spectrometer 94. The energy intensity distribution of the electron beam 93 is measured using a detector 95. A side surface 92 of the first sample 9 corresponds to part of the first rake face portion 11.

[0057] At each of the first position P1, the second position P2, and the third position P3, the electron beam 93 is scanned along a direction parallel to the side surface 92. The direction parallel to the side surface 92 corresponds to the direction parallel to the first rake face portion 11. The spot size of the electron beam 93 is, for example, 1 nm. At each of the first position P1, the second position P2, and the third position P3, the scanning distance of the electron beam 93 is, for example, 10 nm. The scanning distance of the electron beam 93 may be, for example, 1 nm or more and 100 nm or less. As a result of the above, a curve showing the energy loss (K edge) around 300 eV associated with the excitation of carbon K-shell electrons at each of the first position P1, the second position P2, and the third position P3 is obtained.

[0058] Using the energy loss curve obtained by irradiation of the electron beam 93 at the first position P1, the π bond originating from the π bond of carbon in the graphite phase is calculated. * Peak intensity (I π* ) and σ originating from the σ bond of carbon in the graphite and diamond phases, respectively. * Peak intensity (I σ* ) is required. I π* I σ* I at the first position P1 by dividing π* / I σ* Similarly, I at the second position P2 and the third position P3 can be calculated. π* / I σ* is required.

[0059] Similarly, I at the fourth position P4, the fifth position P5, and the sixth position P6 π* / I σ* Specifically, the diamond member 4 is cut along a plane parallel to the second direction 102 using an argon ion slicer. This produces a second sample (not shown) having a thickness of 3 nm or more and 100 nm or less.

[0060] In preparing the second sample, the cutting position of the diamond member 4 is determined so that the side surface of the second sample is formed by the second flank portion 22. From another perspective, in the diamond tool 10 according to the first embodiment, the second sample does not include the graphite altered layer 6. In other words, in the diamond tool 10 according to the first embodiment, the second sample is formed by the diamond portion 5. By using the above-described measurement method for the second sample, the I at each of the fourth position P4, the fifth position P5, and the sixth position P6 can be measured. π* / I σ* is required.

[0061] I of the diamond member 4 on the surface of the first rake face portion 11 (first position P1) π* / I σ* is equal to or greater than 0.2 and equal to or less than 2. I π* / I σ* may be, for example, 0.4 or more and 1.5 or less, or 0.6 or more and 1 or less.

[0062] I of the diamond member at a position (second position P2) 0.5 μm from the surface of the first rake face portion 11 in the first direction 101 π* / I σ* is equal to or greater than 0.2 and equal to or less than 2. I π* / I σ* may be, for example, 0.4 or more and 1.5 or less, or 0.6 or more and 1 or less.

[0063] I of the diamond member 4 at a position (third position P3) 1.0 μm from the surface of the first rake face portion 11 in the first direction 101 π* / I σ* is equal to or greater than 0.001 and equal to or less than 0.1. π* / I σ* may be, for example, 0.002 or more and 0.05 or less, or 0.003 or more and 0.01 or less.

[0064] I π* / I σ* The portion of the diamond member 4 where the value of I is 0.2 or more is defined as the graphite altered layer 6. π* / I σ* The portion of the diamond member 4 where the ratio is less than 0.2 is defined as the diamond portion 5. From another perspective, the graphite altered layer 6 is located at the first position P1 and the second position P2. The diamond portion 5 is located at the third position P3. The diamond portion 5 is located at a position deeper than the third position P3.

[0065] I of the diamond member 4 on the surface of the flank 2 (fourth position P4) π* / I σ* is, for example, not less than 0.001 and not more than 0.1. I of the diamond member 4 at a position (fifth position P5) 0.5 μm from the surface of the flank 2 in the second direction 102 π* / I σ* is equal to or greater than 0.001 and equal to or less than 0.1. π* / I σ* may be, for example, 0.002 or more and 0.05 or less, or 0.003 or more and 0.01 or less.

[0066] I of the diamond member 4 at a position (sixth position P6) 1.0 μm from the surface of the flank 2 in the second direction 102 π* / I σ* is equal to or greater than 0.001 and equal to or less than 0.1. From another perspective, the diamond portion 5 is located at each of the fourth position P4, the fifth position P5, and the sixth position P6.

[0067] In addition, I π* / I σ* In the measurement, the first sample 9 and the second sample are each prepared so that the crystal lattice constituting the diamond member 4 is continuous and does not cleave at each of the first position P1, the second position P2, the third position P3, the fourth position P4, the fifth position P5, and the sixth position P6.

[0068] The same diamond particle may be located at each of the first position P1, second position P2, and third position P3 of the fabricated first sample 9, or different diamond particles may be located therein. Similarly, the same diamond particle may be located at each of the fourth position P4, fifth position P5, and sixth position P6 of the fabricated second sample, or different diamond particles may be located therein.

[0069] <Diamond tool manufacturing method> Next, a method for manufacturing the diamond tool 10 according to the first embodiment will be described.

[0070] Fig. 5 is a flow diagram that schematically shows a method for manufacturing the diamond tool 10 according to the first embodiment. As shown in Fig. 5, the method for manufacturing the diamond tool 10 according to the first embodiment mainly includes a step (S10) of preparing a diamond, a step (S20) of processing the diamond to form the diamond member 4, a step (S30) of joining the diamond member 4 and the main body 8 by brazing, and a step (S40) of laser processing the diamond member 4.

[0071] First, a step (S10) of preparing diamond is carried out. Specifically, for example, either BLPCD or PCD is prepared as the diamond. When BLPCD is used as the diamond, graphite is converted into diamond particles using, for example, a high temperature and high pressure (HTHP) method, and the diamond particles are sintered without using a binder. More specifically, for example, graphite is directly converted into diamond particles while the diamond particles are sintered under high temperature and high pressure conditions of 1800°C to 2500°C and 15 GPa to 25 GPa. In this way, BLPCD is prepared.

[0072] When PCD is used as the diamond, the PCD is prepared by sintering a mixture of a binder and diamond particles produced by a HTHP method or the like.

[0073] Next, a step (S20) of forming the diamond member 4 by processing the diamond is carried out. For example, the diamond is processed using at least one of electric discharge processing using an electric discharge machine, grinding processing using a grinding machine, and laser processing using a laser processing machine. In other words, the diamond is processed by rough processing and precision processing.

[0074] For example, if the diamond tool 10 is a turning indexable cutting tip, the diamond is machined to form a chip having a length of 2 mm to 6 mm, a width of 1 mm to 6 mm, and a thickness of 0.3 mm to 2 mm. For example, if the diamond tool 10 is a drill, the diamond is machined to form a cylindrical shape having a length of 0.5 mm to 5 mm and a diameter of 0.5 mm to 5 mm. The diamond member 4 is formed in this manner.

[0075] Next, a step (S30) of joining the diamond member 4 and the main body portion 8 by brazing is carried out. For example, the diamond member 4 and the main body portion 8 are joined using silver solder. This makes it easier to irradiate the diamond member 4 with a laser 81 in a step (S40) of performing laser processing on the diamond member 4, which will be described later. Therefore, it becomes easier to perform finish processing on the diamond member 4.

[0076] Next, a step (S40) of performing laser processing on the diamond member 4 is carried out. FIG. 6 is a cross-sectional schematic diagram showing the step (S40) of performing laser processing on the diamond member 4. As shown in FIG. 6, a laser 81 is irradiated onto the rake face 1 of the diamond member 4. The irradiation direction B of the laser 81 is, for example, perpendicular to the rake face 1. The irradiation direction B is, for example, the same as the first direction 101. The laser 81 is operated along a direction parallel to the rake face 1. This performs finish processing on the cutting edge of the diamond tool 10.

[0077] For example, a picosecond laser is used as the laser 81. The wavelength of the laser 81 is 532 nm or more and 1064 nm or less. The half width of the spot diameter of the laser 81 is 5 μm or more and 70 μm or less. The focal depth of the laser 81 is 0.5 mm or more and 20 mm or less. The output of the laser 81 is 1 W or more and 20 W or less at the processing point. The scanning speed of the laser 81 is 5 mm / sec or more and 100 mm / sec or less.

[0078] The pulse width of the laser 81 may be set to 1 f (femto) second or more and 1 μsec or less, and the repetition frequency of the laser 81 may be set to 10 Hz or more and 1 MHz or less.

[0079] The surface roughness of a laser-processed surface is affected by each of the above parameters. However, the surface roughness of a laser-processed surface can be controlled by adjusting the inter-spot distance. The inter-spot distance is the interval between the irradiated beam spots. The smaller the inter-spot distance, the greater the overlap of the irradiated beam spots. The inter-spot distance is adjusted by adjusting the repetition frequency and scanning speed of the laser 81. When the scanning speed is V (mm / s) and the repetition frequency of the laser 81 is f (Hz), the inter-spot distance Sd (mm) is calculated as Sd = V / f. The shorter the inter-spot distance Sd, the smaller the surface roughness (Ra) of the laser-processed surface tends to be.

[0080] Compressed air is blown onto a portion of the diamond member 4 close to the processing point. This cools the diamond member 4, preventing the surface of the diamond member 4 from being overheated. Specifically, compressed air is blown onto the diamond member 4 using, for example, a vortex tube (manufactured by Kogi Co., Ltd.). This causes the vortex effect to blow cold air at a temperature lower than room temperature onto the diamond member 4. This allows for effective cooling. This makes it possible to appropriately control the transformation from the diamond crystal structure to the graphite crystal structure in the diamond particles that form the diamond member 4. In this way, the diamond tool 10 according to the first embodiment is manufactured.

[0081] If the half-width of the spot diameter of the laser 81 is less than 5 μm, the laser power may be too low, making it difficult to finish the diamond member 4. If the half-width of the spot diameter of the laser 81 is more than 70 μm, the laser power may be too high, causing the diamond member 4 to crack.

[0082] If the focal depth of the laser 81 is less than 0.5 mm, defocusing may make it difficult to finish the diamond member 4. If the output of the laser 81 is less than 1 W at the processing point, the laser power may be too low and therefore difficult to finish the diamond member 4. If the output of the laser 81 is more than 20 W at the processing point, the laser power may be too high and therefore the diamond member 4 may crack.

[0083] If the scanning speed of the laser 81 is less than 5 mm / sec, an excessively deep portion of the diamond member 4 may be laser-processed, which may cause cracking of the diamond member 4. If the scanning speed of the laser 81 exceeds 100 mm / sec, the diamond member 4 may hardly be processed.

[0084] If the pulse width of the laser 81 is less than 1 fsec, the time required for laser processing may be excessively long. In addition, in this case, the laser device may be extremely expensive. If the pulse width of the laser 81 is more than 1 μsec, thermal processing may become dominant, and the transformation from the diamond crystal structure to the graphite crystal structure may proceed excessively.

[0085] If the repetition rate of the laser 81 is less than 10 Hz, thermal processing becomes dominant, and the transformation from the diamond crystal structure to the graphite crystal structure may proceed excessively. If the repetition rate of the laser 81 exceeds 1 MHz, the next laser 81 pulse arrives before the energy of the irradiated laser 81 pulse is consumed at the processing point, and the thermal load at the processing point may become excessively large. Therefore, the transformation from the diamond crystal structure to the graphite crystal structure may proceed excessively.

[0086] Next, the effects of the diamond tool 10 according to the first embodiment will be described.

[0087] Chip welding or chip clogging can occur on the rake face of a diamond tool. In this case, the part of the diamond tool near the cutting edge can be chipped when machining a workpiece. This can result in an excessively short tool life.

[0088] If the rake face Ra is too small, the rake face may be too smooth, preventing coolant from remaining on the rake face when machining the workpiece. In this case, the frictional force generated between the chips and the rake face increases. This makes it more likely that chips will weld together and become clogged on the rake face. On the other hand, if the rake face Ra is too large, the frictional force generated between the chips and the rake face increases due to the roughness of the rake face. This makes it more likely that chips will weld together and become clogged on the rake face.

[0089] The diamond tool 10 according to the first embodiment has a first rake face portion 11 and a flank 2. The ridgeline between the first rake face portion 11 and the flank 2 forms a cutting edge 3. The Ra of the first rake face portion 11 is 0.1 μm or more and 1.0 μm or less.

[0090] By setting the Ra of the first rake face portion 11 to 0.1 μm or more, the first rake face portion 11 is provided with a sufficient amount of minute irregularities. This allows coolant to penetrate between the minute irregularities when machining a workpiece. This allows coolant to remain on the first rake face portion 11. This improves lubrication between the first rake face portion 11 and the chips. This prevents chip welding and chip clogging on the rake face 1. As a result, the tool life of the diamond tool 10 can be improved.

[0091] By setting the Ra of the first rake face portion 11 to 1.0 μm or less, excessive roughness of the first rake face portion 11 is suppressed. This makes it possible to prevent chip welding and chip clogging on the rake face 1. As a result, the tool life of the diamond tool 10 can be improved.

[0092] According to the diamond tool 10 according to the first embodiment, the I of the diamond member 4 on the surface of the first rake face portion 11 (first position P1) π* / I σ* is between 0.2 and 2. π* / I σ* When the ratio of the graphite phase to the surface of the first rake face portion 11 is 0.2 or more, the ratio of the graphite phase to the surface of the first rake face portion 11 is sufficiently improved. Therefore, the graphite phase has higher lubricity than the diamond phase, and the lubricity of the first rake face portion 11 can be improved. This makes it possible to prevent chip welding and chip clogging on the rake face 1. As a result, the tool life of the diamond tool 10 can be improved.

[0093] The graphite phase is softer than the diamond phase. Therefore, if the graphite phase is present in an excessively high proportion on the surface of the first rake face 11, the strength of the portion of the diamond member 4 close to the first rake face 11 will be excessively reduced. π* / I σ* By making the ratio of the graphite phase in the surface of the first rake face portion 11 2 or less, it is possible to prevent the graphite phase from being present in an excessively high proportion. Therefore, it is possible to prevent the strength of the diamond member 4 from being excessively reduced. This makes it possible to prevent chipping of the diamond member 4. As a result, it is possible to improve the tool life of the diamond tool 10.

[0094] According to the diamond tool 10 according to the first embodiment, the I of the diamond member 4 at a position (third position P3) 1.0 μm from the surface of the first rake face portion 11 in the normal direction of the first rake face portion 11 π* / I σ*is equal to or greater than 0.001 and equal to or less than 0.1. Therefore, the abundance ratio of the graphite phase is sufficiently reduced in the portion of the diamond member 4 close to the third position P3. This sufficiently improves the strength of the portion of the diamond member 4 close to the third position P3. Therefore, chipping of the diamond member 4 can be prevented.

[0095] If the surface roughness of the flank 2 is excessively rough, the flank 2 may come into contact with the workpiece surface during machining, thereby worsening the surface roughness of the workpiece surface. According to the diamond tool 10 according to the first embodiment, the Ra of the flank 2 is smaller than the Ra of the first rake face portion 11. Therefore, the Ra of the flank 2 is sufficiently reduced. This makes it possible to prevent the surface roughness of the workpiece surface from worsening.

[0096] Since the flank 2 is the portion that comes into contact with the work surface of the workpiece, the portion of the diamond tool 10 that is close to the flank 2 is required to have higher strength than the portion of the diamond tool 10 that is close to the rake face 1. According to the diamond tool 10 of the first embodiment, the I of the diamond member 4 at a position (second position P2) 0.5 μm from the surface of the first rake face portion 11 in the normal direction of the first rake face portion 11 is π* / I σ* is 0.2 or more and 2 or less. I of the diamond member 4 at a position (fifth position P5) 0.5 μm from the surface of the flank 2 in the normal direction of the flank 2 π* / I σ* is greater than or equal to 0.001 and less than or equal to 0.1.

[0097] Therefore, the strength of the portion of the diamond tool 10 close to the fifth position P5 is improved compared to the strength of the portion of the diamond tool 10 close to the second position P2. Therefore, chipping of the diamond member 4 can be prevented.

[0098] According to the diamond tool 10 according to the first embodiment, I at the second position P2 π* / I σ*When the ratio is 0.2 or more and 2 or less, the lubricity of the first rake face portion 11 can be effectively improved.

[0099] (Variation) Fig. 7 is a cross-sectional schematic diagram showing the configuration of a diamond tool 10 according to a modified example of the first embodiment. The cross section shown in Fig. 7 corresponds to the cross section shown in Fig. 1. As shown in Fig. 7, the diamond tool 10 does not have to have a main body 8 and a brazing material 7. From another perspective, the diamond tool 10 may be formed by a diamond member 4.

[0100] The manufacturing method of the diamond tool 10 according to the modified example of the first embodiment does not have to include the step (S30) of joining the diamond member 4 and the main body 8 by brazing. From another perspective, in the manufacturing method of the diamond tool 10 according to the modified example of the first embodiment, the step (S20) of forming the diamond member 4 by processing diamond is followed by the step (S40) of performing laser processing on the diamond member 4.

[0101] The diamond tool 10 according to the present disclosure may have a coating covering at least a portion of the rake face 1 and the flank face 2. The coating is formed by a physical vapor deposition method such as ion plating, arc ion plating, sputtering, or ion mixing. The coating may also be formed by a chemical vapor deposition method.

[0102] In the diamond tool 10 according to the present disclosure, the diamond member 4 may be formed of a single-crystal diamond (SCD). When an SCD is used as the diamond, the SCD is prepared in the manufacturing method of the diamond tool 10 using, for example, a HTHP method or a chemical vapor deposition (CVD) method.

[0103] (Second embodiment) Next, the configuration of the diamond tool 10 according to the second embodiment will be described. The diamond tool 10 according to the second embodiment differs from the diamond tool 10 according to the first embodiment mainly in that the proportion of graphite phase present on the surface of the flank 2 is high, but in other respects it is substantially the same as the diamond tool 10 according to the first embodiment. Below, the differences from the diamond tool 10 according to the first embodiment will be mainly described.

[0104] FIG. 8 is a cross-sectional schematic diagram showing the configuration of a diamond tool 10 according to the second embodiment. The cross section shown in FIG. 8 corresponds to the cross section shown in FIG. 1. As shown in FIG. 8, according to the diamond tool 10 according to the second embodiment, the graphite-altered layer 6 has a first portion 61 and a second portion 62. The first portion 61 forms the first rake face portion 11. The first portion 61 forms the first flank face portion 21. The configuration of the first portion 61 is substantially the same as the configuration of the graphite-altered layer 6 of the diamond tool 10 according to the first embodiment.

[0105] The second portion 62 is continuous with the first portion 61. The second portion 62 forms the second flank portion 22. From another perspective, the flank 2 is formed by the graphite-affected layer 6. The thickness of the second portion 62 in the second direction 102 is smaller than the thickness of the first portion 61 in the first direction 101.

[0106] 9 is a schematic cross-sectional view taken along the line VIII-VIII in FIG. 8. The cross section shown in FIG. 9 corresponds to the cross section shown in FIG. 3. The I of the diamond member 4 on the surface of the flank 2 (fourth position P4) π* / I σ* is equal to or greater than 0.2 and equal to or less than 2. I π* / I σ* may be, for example, 0.4 or more and 1.5 or less, or 0.6 or more and 1 or less.

[0107] From another perspective, the graphite-affected layer 6 is located at the fourth position P4, and the diamond portion 5 is located at each of the fifth position P5 and the sixth position P6. The diamond portion 5 is located at a position deeper than the fifth position P5.

[0108] FIG. 10 is a cross-sectional schematic view illustrating a manufacturing method of a diamond tool 10 according to a second embodiment. FIG. 10 shows a step (S40) of performing laser processing on a diamond member 4. As shown in FIG. 10, in the step (S40) of performing laser processing on a diamond member 4, a laser 81 is irradiated onto a rake face 1, and then a laser 81 is irradiated onto a flank face 2. An irradiation direction C of the laser 81 is, for example, perpendicular to the flank face 2. In other words, the irradiation direction C is, for example, parallel to the second direction 102. The laser 81 is scanned along a direction parallel to the flank face 2.

[0109] According to the diamond tool 10 according to the second embodiment, the I of the diamond member 4 on the surface of the flank 2 (the fourth position P4) π* / I σ* When the ratio is 0.2 or more, the proportion of the graphite phase on the surface of the flank 2 is sufficiently improved. This improves the lubricity of the flank 2. This reduces the frictional force between the workpiece and the flank 2 when machining the workpiece. As a result, it is possible to prevent the surface roughness of the workpiece surface from becoming excessively worse.

[0110] According to the diamond tool 10 according to the second embodiment, the I of the diamond member 4 at the fourth position P4 π* / I σ* By making the ratio of the graphite phase on the surface of the flank 2 equal to or less than 2, the ratio is prevented from becoming excessively high. Therefore, the strength of the diamond member 4 is prevented from decreasing excessively. This makes it possible to prevent chipping of the diamond member 4. As a result, the tool life of the diamond tool 10 can be improved.

[0111] Although the configuration in which the cutting edge 3 has a sharp edge shape (the ridgeline between the rake face 1 and the flank 2) has been described above, the configuration of the diamond tool 10 according to the present disclosure is not limited to the above configuration. Specifically, the cutting edge 3 may have a shape in which the sharp edge is rounded (R), a shape in which the sharp edge is chamfered, or a shape in which the sharp edge is rounded and chamfered.

[0112] When the cutting edge 3 has a shape in which a rounded sharp edge is provided, or when the cutting edge 3 has a shape in which a chamfered sharp edge is provided, the straight line at the position where an imaginary plane extending from the cutting face 1 of the diamond member 4 intersects with an imaginary plane extending from the relief face 2 is regarded as the cutting edge 3. [Example]

[0113] Diamond tools 10 according to Samples 1 to 10 were prepared. Samples 1, 6 to 9 were examples. Samples 2 to 5, and 10 were comparative examples. The diamond tools 10 according to Samples 1 to 10 had the same shape as the cutting insert for turning specified by catalog number "NF-DNMA150408" (Sumitomo Electric Industries, Ltd.).

[0114] (Sample preparation) <Sample 1> First, the step (S10) of preparing the diamond was carried out. Specifically, a sintered diamond (PCD) was prepared by using the conventionally known HTHP method (sintering at a pressure of 6 GPa and a temperature of 1500°C for 15 minutes). The diameter of the diamond particles constituting this PCD (D 50 ) was 10 μm.

[0115] Next, a step (S20) of forming a diamond member 4 by machining the diamond was carried out. Specifically, the PCD was machined using a commercially available wire electric discharge machine to cut out an isosceles triangle with an apex angle of 55°. The base of the isosceles triangle was 6.5 mm and the height was 5 mm. In this way, the diamond member 4 was formed.

[0116] Next, a step (S30) of joining the diamond member 4 and the main body 8 by brazing was carried out. Specifically, the main body 8 was prepared by processing Igetalloy (registered trademark, material type: G10E), a cemented carbide alloy manufactured by Sumitomo Electric Industries, Ltd. The main body 8 and the diamond member 4 were joined by brazing.

[0117] Next, a step (S40) of performing laser processing on the diamond member 4 was carried out. Laser processing was carried out on both the rake face 1 and the flank face 2 of the diamond member 4 using the following irradiation conditions. In this way, finishing of the cutting edge of the diamond tool 10 was carried out. In this way, the diamond tool 10 relating to sample 1 was obtained.

[0118] (Irradiation conditions) Laser wavelength: 1064nm Laser spot diameter half width: 40 μm Laser focal depth: 1.5 mm Laser power at processing point: 5W Laser scanning speed: 6mm / min Laser pulse width: 10 picoseconds Laser repetition rate: 400kHz

[0119] <Sample 2> The preparation of the diamond tool 10 for Sample 2 differed from Sample 1 in the following respects. Specifically, when laser processing the cutting face 1 in step S40, irradiation conditions were used in which the laser scanning speed was faster and the laser repetition frequency was lower compared to the irradiation conditions for Sample 1. From another perspective, irradiation conditions in which the inter-spot distance Sd was longer compared to the irradiation conditions for Sample 1 were used. As a result, a sample was obtained in which the Ra of the first cutting face portion 11 was larger compared to Sample 1.

[0120] <Sample 3> The preparation of the diamond tool 10 for Sample 3 differed from Sample 1 in the following respects. Specifically, when laser processing the cutting face 1 in step S40, irradiation conditions were used in which the laser scanning speed was slower and the laser repetition frequency was higher than those for Sample 1. From another perspective, irradiation conditions in which the inter-spot distance Sd was shorter than those for Sample 1 were used. As a result, a sample with a smaller Ra of the first cutting face portion 11 was obtained compared to Sample 1.

[0121] <Sample 4> The preparation of the diamond tool 10 for Sample 4 differed from Sample 1 in the following respects. Specifically, when laser processing the rake face 1 in step S40, irradiation conditions were used under which the output of the laser 81 at the processing point was higher than that of Sample 1. As a result, a sample was obtained in which the proportion of graphite phase in the portion close to the first rake face portion 11 was higher than that of Sample 1.

[0122] <Sample 5> The preparation of the diamond tool 10 of Sample 5 differed from Sample 1 in the following respects. Specifically, in step S40, the rake face 1 was ground. In step S40, laser processing was not performed on the rake face 1. As a result, a sample was obtained in which the proportion of graphite phase in the portion close to the rake face 1 was smaller than that of Sample 1.

[0123] <Sample 6> The preparation of the diamond tool 10 for sample 6 differed from that for sample 1 in the following respects. Specifically, when laser processing the flank 2 in step S40, irradiation conditions were used in which the laser scanning speed was faster and the laser repetition frequency was lower compared to the irradiation conditions for sample 1. From another perspective, irradiation conditions in which the inter-spot distance Sd was longer compared to the irradiation conditions for sample 1 were used. As a result, a sample with a larger Ra of the flank 2 was obtained compared to sample 1.

[0124] <Sample 7> The preparation of the diamond tool 10 for Sample 7 differed from Sample 1 in the following respects. Specifically, when laser processing the rake face 1 in step S40, conditions were used in which the flow rate of compressed air blown onto the portion of the diamond member 4 close to the processing point was lower than the conditions for Sample 1. As a result, a sample was obtained in which the thickness of the graphite-altered layer 6 in the normal direction of the first rake face portion 11 was thicker than that of Sample 1.

[0125] <Sample 8> The preparation of the diamond tool 10 of Sample 8 differed from Sample 1 in the following respects. Specifically, in step S40, the flank 2 was ground. In step S40, the flank 2 was not laser processed. As a result, a sample was obtained in which the proportion of graphite phase in the portion close to the flank 2 was smaller than that of Sample 1.

[0126] <Sample 9> The preparation of the diamond tool 10 for Sample 9 differed from Sample 1 in the following respects. Specifically, when laser processing the flank 2 in step S40, conditions were used in which the flow rate of compressed air blown onto the portion of the diamond member 4 close to the processing point was lower than the conditions for Sample 1. As a result, a sample was obtained in which the thickness of the graphite-affected layer 6 in the normal direction of the flank 2 was thicker than that of Sample 1.

[0127] <Sample 10> The preparation of the diamond tool 10 of Sample 10 differed from Sample 1 in the following respects. Specifically, in step S40, the cutting edge of the diamond tool 10 was finished by grinding each of the rake face 1 and the flank 2. In step S40, laser processing was not performed on each of the rake face 1 and the flank 2. From another perspective, the manufacturing method of the diamond tool 10 of Sample 10 is a conventional grinding process using a grinding wheel.

[0128] (Graphite phase abundance ratio (I π* / I σ* ) Measurement Using the above-mentioned measurement method, the abundance ratio of the graphite phase in the diamond tool 10 of Samples 1 to 10 was measured. Specifically, at positions at distances of 0 μm, 0.5 μm, and 1.0 μm from the first rake face 11 in the first direction 101 and at positions at distances of 0 μm, 0.5 μm, and 1.0 μm from the flank 2 in the second direction 102, the abundance ratio of the graphite phase in the diamond tool 10 of Samples 1 to 10 was measured. π* / I σ* In other words, at each of the first position P1, the second position P2, the third position P3, the fourth position P4, the fifth position P5, and the sixth position P6, I π* / I σ* was measured.

[0129] (Cutting test) Cutting tests were conducted using diamond tools 10 of samples 1 to 10. The workpiece was cemented carbide (VM-40 (dimensions: diameter φ60 mm x length 100 mm), hardness: HRA88). The workpiece was cut using the following cutting conditions. In the cutting test, cutting was stopped when either the size of the fracture or the size of the chipping occurring in the diamond member 4 exceeded 0.1 mm. The time from the start of the test to that point was measured. It is considered that the longer the time, the better the tool life. The measured times are shown in the "Fracture Resistance [min]" section in Table 1 below.

[0130] <Cutting conditions> Processing machine: lathe Cutting speed Vc:10m / min Feed rate f: 0.05 mm / rev Depth of cut ap: 0.05mm / rev Cutting oil (coolant): Yes

[0131] (Evaluation results)

[0132] [Table 1]

[0133] As shown in Table 1, the Ra of the first rake face portion 11 was 0.3 μm or more and 0.9 μm or less in Samples 1 and 4 to 10. In Sample 2, the Ra of the first rake face portion 11 was 1.3 μm. In Sample 3, the Ra of the first rake face portion 11 was 0.08 μm.

[0134] In samples 1 to 3 and 6 to 9, I on the surface of the first rake face portion 11 (first position P1) π* / I σ* was 0.3 or more and 1.1 or less. In sample 4, I π* / I σ* In samples 5 and 10, I at the first position P1 was 2.1. π* / I σ* was 0.005.

[0135] In samples 1 to 4 and 6 to 9, I at a position (second position P2) at a distance of 0.5 μm from the first rake face portion 11 in the first direction 101 π* / I σ* was 0.2 or more and 0.8 or less. In samples 5 and 10, I at the second position P2 π* / I σ* was 0.005.

[0136] In samples 1 to 6, 8, and 9, I at a position (third position P3) at a distance of 1.0 μm from the first rake face portion 11 in the first direction 101 π* / I σ* was 0.005 or more and 0.03 or less. In sample 7, I π* / I σ* In sample 10, I at the third position P3 was 0.3. π* / I σ* was 0.0005.

[0137] In samples 1, 2, 4, 7, and 8, the Ra of the flank 2 was smaller than the Ra of the first rake face portion 11. In samples 3, 5, 6, 9, and 10, the Ra of the flank 2 was equal to or greater than the Ra of the first rake face portion 11. In samples 1 to 5 and 7 to 10, the Ra of the flank 2 was 0.1 μm or more and 0.5 μm or less. In sample 6, the Ra of the flank 2 was 1.5 μm.

[0138] In specimens 1 to 7 and 9, I on the surface of flank 2 (fourth position P4) π* / I σ* was 0.5 or more and 0.8 or less. In samples 8 and 10, I at the fourth position P4 π* / I σ* was 0.005.

[0139] In samples 1 to 8 and 10, I at a position (fifth position P5) at a distance of 0.5 μm from the flank 2 in the second direction 102 π* / I σ* In sample 9, I at the fifth position P5 was 0.005 or more and 0.006 or less. π* / I σ* was 0.3.

[0140] In samples 1 to 8 and 10, I at a position (sixth position P6) at a distance of 1.0 μm from the flank 2 in the second direction 102 π* / I σ* In sample 9, I at the sixth position P6 was 0.005 or more and 0.006 or less. π* / I σ* was 0.3.

[0141] As shown in Table 1, the diamond tools 10 according to Samples 1 to 9 had improved chipping resistance compared to the diamond tool 10 according to Sample 10. Compared with Samples 2 to 5 and 10, the Ra of the first rake face portion 11 was 0.1 μm or more and 1.0 μm or less, and the I π* / I σ*The specimens (specimens 1 and 6 to 9) in which I was 0.2 or more and 2 or less had improved fracture resistance. π* / I σ* is 0.2 or more and 2 or less, and I at the fifth position P5 π* / I σ* The specimens (specimens 1, 6, and 7) in which I was 0.001 or more and 0.1 or less had improved fracture resistance. π* / I σ* In sample 1 in which Ra was 0.001 or more and 0.1 or less and Ra of the flank 2 was smaller than Ra of the first rake face portion 11, the fracture resistance was further improved.

[0142] From the above results, it was confirmed that the diamond tool 10 according to the example can improve the tool life compared to the diamond tool 10 according to the comparative example. π* / I σ* is 0.2 or more and 2 or less, and I at the fifth position P5 π* / I σ* It was confirmed that the tool life can be effectively improved by setting I to be 0.001 or more and 0.1 or less. π* / I σ* It has been confirmed that when Ra is 0.001 or more and 0.1 or less and Ra of the flank 2 is smaller than Ra of the first rake face portion 11, the tool life can be effectively improved.

[0143] The embodiments and examples disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims, not by the above-described embodiments, and is intended to include any modifications within the scope of the claims and meanings equivalent to the claims. [Explanation of symbols]

[0144] 1 rake face, 2 flank face, 3 cutting edge, 4 diamond member, 5 diamond portion, 6 graphite altered layer, 7 brazing material, 8 main body portion, 9 first sample, 10 diamond tool, 11 first rake face portion, 12 second rake face portion, 19 connection point, 21 first flank face portion, 22 second flank face portion, 30 bonded surface, 31 first bonded surface portion, 32 second bonded surface portion, 61 first portion, 62 second portion, 81 laser, 91 cross section, 92 side surface, 93 electron beam, 94 spectrometer, 95 detector, 101 first direction, 102 second direction, A arrow, B, C irradiation direction, H width, P1 first position, P2 second position, P3 third position, P4 fourth position, P5 fifth position, P6 sixth position.

Claims

1. A diamond member including a rake face having a first rake face portion and a second rake face portion, and a relief face connected to the rake face, the first rake face portion is continuous with the flank face, a ridgeline between the first rake face portion and the flank face forms a cutting edge, The arithmetic mean roughness of the first rake face portion is 0.1 μm or more and 1.0 μm or less, the second rake face portion is continuous with the first rake face portion and is spaced apart from the flank face, The diamond member is a diamond phase having a diamond crystal structure; a graphite phase having a crystalline structure of graphite; measuring the energy loss associated with the excitation of carbon K shell electrons by electron energy loss spectroscopy using a transmission electron microscope for the diamond member; Using the energy loss, π bonds originating from the carbon π bonds in the graphite phase are calculated. ＊ The intensity of the peak and the σ bond of carbon in each of the graphite phase and the diamond phase ＊ The peak intensity is calculated, The π ＊ The intensity of the peak is expressed as σ ＊ The value divided by the peak intensity is I π＊ / I σ＊ In this case, The I of the diamond member on the surface of the first rake face portion π＊ / I σ＊ is equal to or greater than 0.2 and equal to or less than 2, the diamond member includes a diamond portion and a graphite altered layer; the abundance ratio of the graphite phase in the graphite-altered layer is greater than the abundance ratio of the graphite phase in the diamond portion, the first rake face portion is formed by the graphite alteration layer, The second rake face portion is formed by the diamond portion.

2. The diamond tool according to claim 1, wherein the arithmetic mean roughness of the flank is smaller than the arithmetic mean roughness of the first rake face portion.

3. a main body; a brazing material joining the diamond member and the main body, the diamond member is formed of polycrystalline sintered diamond, The I of the diamond member at a position 1.0 μm from the surface of the first rake face portion in the normal direction of the first rake face portion π＊ / I σ＊ The diamond tool according to claim 1 or 2, wherein is 0.001 or more and 0.1 or less.

4. The I of the diamond member on the surface of the flank π＊ / I σ＊ The diamond tool according to claim 1 or claim 2, wherein is 0.2 or more and 2 or less.

5. The I of the diamond member at a position 0.5 μm from the surface of the first rake face portion in the normal direction of the first rake face portion π＊ / I σ＊ is equal to or greater than 0.2 and equal to or less than 2, The I of the diamond member at a position 0.5 μm from the surface of the flank in the normal direction of the flank. π＊ / I σ＊ The diamond tool according to claim 1 or 2, wherein is 0.001 or more and 0.1 or less.

Images