Sintered body and cutting tool

Abstract

The sintered body has diamond particles and a bonding material. The concentration of boron in the diamond particles is 0.001 mass% or more and 0.9 mass% or less. The concentration of boron in the bonding material is 0.5 mass% or more and 40 mass% or less.

Description

Technical Field

[0001] This disclosure relates to sintered bodies and cutting tools. This application claims priority based on Japanese Patent Application No. 2020-198393, filed on November 30, 2020. The entire contents of that Japanese patent application are incorporated herein by reference. Background Technology

[0002] Patent Document 1 (Japanese Patent Application Publication No. 2008-133172) discloses a sintered body. The sintered body disclosed in Patent Document 1 is formed by mixing boron-doped diamond powder and carbonate powder, and then heating and pressurizing the mixture.

[0003] Patent Document 2 (Japanese Patent Application Publication No. 58-199777) discloses a sintered body. The sintered body described in Patent Document 2 is formed by mixing diamond powder and catalyst metal powder, and then heating and pressurizing the mixture. Furthermore, the catalyst metal powder includes boron carbide powder and metal powders (iron, nickel, cobalt, etc.).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-133172

[0007] Patent Document 2: Japanese Patent Application Publication No. 58-199777 Summary of the Invention

[0008] The sintered body disclosed herein comprises diamond particles and a binder material. The boron concentration in the diamond particles is 0.001% by mass or more and 0.9% by mass or less. The boron concentration in the binder material is 0.5% by mass or more and 40% by mass or less. Attached Figure Description

[0009] Figure 1 This is a top view of cutting blade 100.

[0010] Figure 2 This is a 3D view of cutting blade 100.

[0011] Figure 3 This is a process diagram showing the manufacturing method of the sintered body constituting the blade tip 20. Detailed Implementation

[0012] [The problem this disclosure aims to solve]

[0013] The inventors of this invention have conducted in-depth research and have discovered that when the sintered bodies described in Patent Document 1 and Patent Document 2 are applied to cutting tools, there is potential for improvement in tool life. This disclosure provides a sintered body that can improve tool life when applied to cutting tools.

[0014] [The Effects of This Disclosure]

[0015] The sintered body according to this disclosure can improve tool life when applied to cutting tools.

[0016] [Description of embodiments of this disclosure]

[0017] First, embodiments of this disclosure will be described.

[0018] (1) In one embodiment, the sintered body comprises diamond particles and a binder material. The boron concentration in the diamond particles is 0.001% by mass or more and 0.9% by mass or less. The boron concentration in the binder material is 0.5% by mass or more and 40% by mass or less.

[0019] The sintered body according to (1) above can improve tool life when applied to cutting tools.

[0020] (2) Alternatively, in the sintered body of (1) above, the boron concentration in the diamond particles is 0.005% by mass or more and 0.1% by mass or less. Alternatively, the boron concentration in the bonding material is 0.6% by mass or more and 33% by mass or less.

[0021] The sintered body according to (2) above can further improve tool life when applied to cutting tools.

[0022] (3) Alternatively, in the sintered body of (1) or (2) above, the average particle size of the diamond particles is 0.1 μm or more and 50 μm or less. Alternatively, the proportion of diamond particles in the sintered body is 80% or more by volume and 99% or less by volume.

[0023] (4) Alternatively, in the sintered bodies described in (1) to (3) above, the bonding material may include at least one element selected from the group consisting of elemental metals, alloys, and intermetallic compounds. Alternatively, the elemental metals, alloys, and intermetallic compounds may include at least one metallic element selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements, iron, aluminum, silicon, cobalt, and nickel.

[0024] (5) Alternatively, in the sintered bodies described in (1) to (3) above, the bonding material may include at least one element selected from the group consisting of compounds and solid solutions derived from compounds. Alternatively, the compound may consist of at least one element selected from the group consisting of elemental metals, alloys, and intermetallic compounds, and at least one element selected from the group consisting of nitrogen, carbon, and oxygen. Alternatively, the elemental metals, alloys, and intermetallic compounds may include at least one metallic element selected from the group consisting of Group IV elements, Group V elements, Group VI elements, iron, aluminum, silicon, cobalt, and nickel.

[0025] (6) Alternatively, in the sintered body of (1) to (5) above, the bonding material may contain at least cobalt.

[0026] (7) One embodiment of the cutting tool has a cutting tip. The cutting tip is formed from the sintered body described in (1) to (6) above.

[0027] The cutting tool described in (7) above can improve tool life.

[0028] [Details of the embodiments disclosed herein]

[0029] The embodiments of this disclosure will be described in detail with reference to the accompanying drawings. In the following drawings, the same or equivalent parts are labeled with the same reference numerals, and the description will not be repeated.

[0030] The cutting tool involved in the embodiments is, for example, a cutting insert 100. The cutting tool involved in the embodiments is not limited to the cutting insert 100; the cutting insert 100 will be described below as an example of the cutting tool involved in the embodiments.

[0031] (The configuration of the cutting tool involved in the implementation)

[0032] The structure of the cutting insert 100 will be explained.

[0033] <Overview of the structure of cutting insert 100>

[0034] Figure 1 This is a top view of cutting blade 100. Figure 2 This is a 3D view of the cutting blade 100. (See image below.) Figure 1 as well as Figure 2 As shown, the cutting insert 100 has a base material 10 and a cutting tip 20. The cutting insert 100 is polygonal in shape (e.g., triangular) when viewed from above. The polygonal shape (triangular shape) may not be strictly polygonal (triangular). More specifically, the corners of the cutting insert 100 when viewed from above may also be rounded.

[0035] The substrate 10 is polygonal in shape (e.g., triangular) when viewed from above. The substrate 10 has a top surface 10a, a bottom surface 10b, and a side surface 10c. The top surface 10a and the bottom surface 10b are end faces of the substrate 10 in the thickness direction. The bottom surface 10b is the surface opposite to the top surface 10a in the thickness direction of the substrate 10. The side surface 10c is the surface connected to the top surface 10a and the bottom surface 10b.

[0036] The top surface 10a has a mounting portion 10d. When viewed from above, the mounting portion 10d is located at a corner of the top surface 10a. The distance between the top surface 10a at the mounting portion 10d and the bottom surface 10b is smaller than the distance between the top surface 10a and the bottom surface 10b outside the mounting portion 10d. That is, a step exists between the mounting portion 10d and the portion of the top surface 10a outside the mounting portion 10d.

[0037] A through hole 11 is formed in the substrate 10. The through hole 11 penetrates the substrate 10 in the thickness direction. The through hole 11 is formed at the center of the substrate 10 when viewed from above. The cutting blade 100 is provided for cutting, for example, by inserting a fixing member (not shown) into the through hole 11 and fastening the fixing member to a tool holder (not shown). However, the through hole 11 may not be formed in the substrate 10.

[0038] The substrate 10 is formed, for example, of cemented carbide. Cemented carbide is a composite material formed by sintering carbide particles and a binder material. The carbide particles are, for example, particles of tungsten carbide, titanium carbide, tantalum carbide, etc. The binder material is, for example, cobalt, nickel, iron, etc. However, the substrate 10 may also be formed of materials other than cemented carbide.

[0039] The cutting tip 20 is mounted on the mounting portion 10d. The cutting tip 20 is mounted to the substrate 10, for example, by brazing. The cutting tip 20 has a rake face 20a, a flank face 20b, and a cutting edge 20c. The rake face 20a is connected to a portion of the top surface 10a other than the mounting portion 10d. The flank face 20b is connected to the side surface 10c. The cutting edge 20c is formed along the ridge line of the rake face 20a and the flank face 20b. A backing metal 21 may also be disposed on the bottom surface of the cutting tip 20 (the surface opposite to the rake face 20a). The backing metal 21 is, for example, formed of cemented carbide.

[0040] <Detailed Structure of the Sintered Body Constituting the Blade Tip 20>

[0041] The blade tip 20 is formed of a sintered body comprising diamond particles and a binder material. The average particle size of the diamond particles in the sintered body constituting the blade tip 20 is preferably 0.1 μm or more and 50 μm or less. The proportion (volume ratio) of the diamond particles in the sintered body constituting the blade tip 20 is preferably 80% or more and 99% or less. The binder material includes, for example, cobalt. In addition to cobalt, the binder material may also include titanium. Cobalt is preferably the most abundant component in the binder material.

[0042] The average particle size of the diamond particles in the sintered body constituting the tip 20 is calculated by the following method.

[0043] In calculating the average particle size of the diamond particles in the sintered body constituting the blade tip 20, firstly, a sample including a cross-section is cut from any position of the blade tip 20. This sample cutting is performed, for example, using a focused ion beam device, a cross-section polishing machine, or the like.

[0044] Second, the cross-section of the cut sample was observed using a scanning electron microscope (SEM). This observation yielded a reflected electron image of the cross-section of the cut sample (hereinafter referred to as a "SEM image"). In the SEM-based observation, the magnification was adjusted to include more than 100 diamond particles within the measurement field of view. SEM images were acquired at five locations within the cross-section of the cut sample.

[0045] Third, the size distribution of diamond particles within the measurement field of view is obtained by image processing of the SEM image. This image processing is performed using, for example, Win ROOF ver. 7.4.5 and Win ROOF 2018 manufactured by Mitani Corporation. The size of each diamond particle is obtained by calculating the equivalent circle diameter from the area of ​​each diamond particle obtained as a result of image processing. Furthermore, when obtaining the size distribution of the diamond particles, a portion of diamond particles located outside the measurement field of view is not considered.

[0046] Fourth, based on the distribution of diamond particle size within the measurement field of view obtained as described above, the median particle size of the diamond particles within the measurement field of view is determined. The value obtained by averaging this determined median particle size over five SEM images is regarded as the average particle size of the diamond particles in the sintered body constituting the blade tip 20.

[0047] The proportion of diamond particles in the sintered body constituting the tip 20 is calculated using the following method.

[0048] In calculating the proportion of diamond particles in the sintered body constituting the blade tip 20, firstly, a sample including a cross-section is cut from any position of the blade tip 20. This sample cutting is performed, for example, using a focused ion beam device, a cross-section polishing machine, or the like.

[0049] Second, the cross-section of the cut sample was observed using SEM. This observation yielded SEM images of the cross-section of the cut sample. In the SEM-based observation, the magnification was adjusted to include more than 100 diamond particles within the measurement field of view. SEM images were acquired at five locations within the cross-section of the cut sample.

[0050] Third, the proportion of diamond particles contained within the measured field of view is calculated by image processing of the SEM image. This image processing is performed, for example, by binarizing the SEM image using Win ROOF ver. 7.4.5 or Win ROOF 2018 manufactured by Mitani Corporation. The dark field in the binarized SEM image corresponds to the area containing diamond particles. The value obtained by dividing the area of ​​this dark field by the area of ​​the measured region is regarded as the volume ratio of diamond particles in the sintered body constituting the blade tip 20.

[0051] The boron concentration in the diamond particles is 0.001% by mass or more and 0.9% by mass or less. The boron concentration in the bonding material is 0.5% by mass or more and 40% by mass or less. The boron concentration in the bonding material is preferably 0% or more (i.e., the value obtained by subtracting the boron concentration in the diamond particles from the boron concentration in the bonding material is preferably 0% or more). The value obtained by subtracting the boron concentration in the diamond particles from the boron concentration in the bonding material is preferably 30% by mass or less.

[0052] The boron concentration in the diamond particles can be 0.005% by mass or more and 0.1% by mass or less. It can also be 0.6% by mass or more and 33% by mass or less. In this case, the value obtained by subtracting the boron concentration in the diamond particles from the boron concentration in the bonding material is preferably 0.5% by mass or more and 25% by mass or less.

[0053] The boron concentration in the diamond particles and the boron concentration in the bonding material were determined by the following method.

[0054] In determining the boron concentration in diamond particles and the boron concentration in the bonding material, firstly, a sample is cut from any position at the tip 20. Secondly, the cut sample is acid-treated. This acid treatment causes the bonding material components in the sample to be substantially completely dissolved in the acid. That is, the acid-treated sample is essentially composed only of diamond particles.

[0055] The acid treatment described above was performed using an aqueous solution of fluoronitric acid. This aqueous solution was prepared by mixing a 50% concentration aqueous solution of hydrogen fluoride and a 60% concentration aqueous solution of nitric acid in a 1:1 ratio. The acid treatment was performed by immersing the sample in the aqueous solution of fluoronitric acid and maintaining it at 200°C for 48 hours.

[0056] Third, the boron concentration in the diamond particles was determined by glow discharge mass spectrometry analysis of the acid-treated samples. Additionally, the boron concentration in the bonding material was determined by inductively coupled plasma (ICP) analysis of the acid used in the acid treatment.

[0057] <Manufacturing method of the sintered body constituting the blade tip 20>

[0058] Figure 3 This is a process diagram illustrating the manufacturing method of the sintered body constituting the blade tip 20. (Example) Figure 3 As shown, the manufacturing method of the sintered body constituting the blade tip 20 includes a powder preparation step S1, a powder mixing step S2, and a sintering step S3.

[0059] In the powder preparation step S1, diamond powder, binder powder, and boron powder are prepared. Diamond powder is powder of diamond, binder powder is powder formed from the materials constituting the binder, and boron powder is powder of boron. The proportions of diamond powder, binder powder, and boron powder are appropriately selected based on the volume ratio of diamond particles in the sintered body constituting the blade tip 20 and the boron concentration in the diamond particles and binder.

[0060] In the powder mixing step S2, diamond powder, binder powder, and boron powder are mixed. This mixing is performed, for example, using a grinding mill or a ball mill. However, the mixing method is not limited to these. Hereinafter, the mixture of diamond powder, binder powder, and boron powder will be referred to as "mixed powder".

[0061] In sintering step S3, the mixed powder is sintered. This sintering is performed by placing the mixed powder in a container and maintaining it at a predetermined sintering temperature under a predetermined sintering pressure. To prevent impurities from contaminating the mixed powder (sintered body), the container is formed of a high-melting-point metal such as tantalum or niobium.

[0062] The sintering pressure is controlled to increase with the holding time. The sintering process S3 can be divided into multiple processes. These multiple processes include, for example, a first process and a second process. The second process is performed after the first process. The sintering pressure in the second process is greater than the sintering pressure in the first process. The sintering temperature in the second process is higher than the sintering temperature in the first process. The holding time in the second process is shorter than the holding time in the first process.

[0063] The sintering pressure in the first process is, for example, 3 GPa. The sintering pressure in the second process is, for example, 7 GPa. The sintering temperature in the first process is, for example, 1200°C. The sintering temperature in the second process is, for example, 1500°C. The holding time in the first process is appropriately selected based on the boron concentration in the diamond particles contained in the sintered body constituting the blade tip 20 and the boron concentration in the binder material contained in the sintered body. The longer the holding time in the first process, the higher the boron concentration in the diamond particles contained in the sintered body constituting the blade tip 20 becomes, and the lower the boron concentration in the binder material contained in the sintered body becomes. The holding time in the second process is, for example, 1 minute.

[0064] (Effects of the cutting tool involved in the implementation method)

[0065] The following explains the effect of the cutting blade 100.

[0066] By including boron in the diamond particles, the oxidation resistance of the diamond particles is improved, resulting in improved wear resistance of the cutting tip 20. According to the inventors' findings, when the boron concentration in the diamond particles is less than 0.001% by mass, there is no improvement in the oxidation resistance of the diamond particles due to boron. On the other hand, if the boron concentration in the diamond particles exceeds 0.9% by mass, the amount of boron in the diamond particles is excessive, the hardness of the diamond particles decreases, and the wear resistance of the cutting tip 20 actually decreases.

[0067] In sintering step S3, the binder powder melts, and boron powder dissolves in the molten binder. Furthermore, a portion of the diamond powder dissolves in the molten binder, causing diamond particles to re-precipitate, thereby promoting the progress of necking (necking) between the diamond particles. The boron in the dissolved binder acts as a nucleus during this re-precipitation; therefore, when the boron concentration in the binder is less than 0.5% by mass, necking of the diamond particles is unlikely to occur.

[0068] On the other hand, according to the insights discovered by the inventors of the present invention, when the boron concentration in the bonding material exceeds 40% by mass, it is actually difficult to induce the re-precipitation of diamond particles (it is difficult to generate necking between diamond particles). When the necking between diamond particles in the sintered body constituting the tip portion 20 is insufficient (when the strength of the sintered necks formed between diamond particles is low), diamond particles are prone to detach from the sintered body constituting the tip portion 20, resulting in reduced wear resistance.

[0069] In the cutting insert 100, the boron concentration in the diamond particles contained in the sintered body constituting the tip 20 is 0.001% by mass or more and 0.9% by mass or less, thus improving the oxidation resistance of the diamond particles while maintaining their hardness. Furthermore, in the cutting insert 100, the boron concentration in the bonding material contained in the sintered body constituting the tip 20 is 0.5% by mass or more and 40% by mass or less, thus ensuring the strength of the sintered necks formed between the diamond particles. Therefore, the wear resistance of the tip 20 can be improved according to the cutting insert 100.

[0070] (Example)

[0071] The cutting test conducted to confirm the effectiveness of the cutting insert 100 is explained.

[0072] Table 1 shows the samples provided for the cutting test. As shown in Table 1, samples 1 to 22 were provided for the cutting test. In samples 1 to 8, the boron concentration in the bonding material contained in the sintered body constituting the blade tip 20 was kept constant (10% by mass), and the boron concentration in the diamond particles contained in the sintered body was varied.

[0073] Condition A1 is defined as having a boron concentration in the diamond particles contained in the sintered body constituting the blade tip 20 that is 0.001% by mass or more and 0.9% by mass or less. Condition B1 is defined as having a boron concentration in the bonding material contained in the sintered body constituting the blade tip 20 that is 0.5% by mass or more and 40% by mass or less.

[0074] Condition A2 is defined as having a boron concentration in the diamond particles contained in the sintered body constituting the blade tip 20 that is 0.005% by mass or more and 0.1% by mass or less. Condition B2 is defined as having a boron concentration in the bonding material contained in the sintered body constituting the blade tip 20 that is 0.6% by mass or more and 33% by mass or less.

[0075] Samples 1 through 6 satisfy conditions A1 and B1 (condition B2). Samples 1 through 4 also satisfy condition A2. Samples 7 and 8 satisfy condition B1 (condition B2) but not condition A1.

[0076] In samples 9 to 16, the boron concentration in the diamond particles contained in the sintered body constituting the blade tip 20 was kept constant (0.016% by mass), while the boron concentration in the bonding material contained in the sintered body was varied.

[0077] Samples 9 through 14 satisfy conditions A1 (A2) and B1. Samples 9 through 13 also satisfy condition B2. Samples 15 and 16 satisfy condition A1 (A2) but not condition B1.

[0078] In samples 1 to 16, the average particle size of the diamond particles contained in the sintered body constituting the blade tip 20 is 0.5 μm, and the proportion of diamond particles in the sintered body is 90% by volume. In samples 17 to 22, either the average particle size or the proportion of diamond particles contained in the sintered body constituting the blade tip 20 differs from that in samples 1 to 16. Furthermore, in samples 17 to 22, conditions A1 (condition A2) and B1 (condition B2) are satisfied.

[0079] Table 1

[0080] The cutting tests employed three test methods: the first test method, the second test method, and the third test method. The first test method was used to evaluate samples 1-8, the second test method was used to evaluate samples 9-16, and the third test method was used to evaluate samples 17-22. Table 2 shows the details of the first, second, and third test methods.

[0081]

[0082] The results of the cutting tests are shown in Table 3. As shown in Table 3, samples 1 to 6 and samples 9 to 14 showed longer tool life. On the other hand, in samples 7 and 8 and samples 15 and 16, a notch was generated at the tool tip 20 at the initial stage of the cutting process (hereinafter referred to as "initial notch").

[0083] As described above, conditions A1 and B1 are satisfied in samples 1 to 6 and samples 9 to 14, while one of conditions A1 and B1 is not satisfied in samples 7 and 8 and samples 15 and 16. Based on this comparison, it can be seen that satisfying both conditions A1 and B1 improves the tool life of the cutting insert 100.

[0084] Samples 2-5 showed a longer tool life compared to samples 1 and 6. Furthermore, samples 10-13 showed a longer tool life compared to samples 9 and 14.

[0085] As described above, both conditions A2 and B2 are further satisfied in samples 2 to 5 and samples 10 to 13, while neither condition A2 nor condition B2 is satisfied in samples 1 and 6, and samples 9 and 14. This comparison shows that by further satisfying conditions A2 and B2, the tool life of the cutting insert 100 can be further improved.

[0086] Samples 17 through 22 all exhibited long tool life. As mentioned above, samples 17 through 22 satisfied conditions A1 (condition A2) and B1 (condition B2).

[0087] Condition C is defined as the volume percentage of diamond particles contained in the sintered body constituting the blade tip 20 being 80% or more and 99% or less. Condition D is defined as the average particle size of the diamond particles contained in the sintered body constituting the blade tip 20 being 0.1 μm or more and 50 μm or less. Conditions C and D are satisfied in samples 17 to 19, while one of conditions C and D is not satisfied in samples 20 to 22.

[0088] Samples 17-19 exhibit a longer tool life compared to samples 20-22. This comparison suggests that the tool life of the cutting insert 100 can be further improved by further satisfying conditions C and D.

[0089] Table 3

[0090] (Modified Example)

[0091] In the above description, the case in which the bonding material contained in the sintered body constituting the blade tip 20 is cobalt was used as an example, but the bonding material contained in the sintered body constituting the blade tip 20 is not limited to cobalt.

[0092] The bonding material contained in the sintered body constituting the blade tip 20 may include at least one element selected from the group consisting of elemental metals, alloys, and intermetallic compounds. The elemental metals, alloys, and intermetallic compounds include at least one metallic element selected from the group consisting of Group IV elements (e.g., titanium, zirconium, hafnium), Group V elements (e.g., vanadium, tantalum, niobium), Group VI elements (e.g., chromium, molybdenum, tungsten), aluminum, iron, silicon, cobalt, and nickel. Furthermore, the aforementioned periodic table refers to a so-called long-period periodic table.

[0093] The bonding material contained in the sintered body constituting the blade tip 20 may include at least one element selected from the group consisting of compounds and solid solutions derived from those compounds. The compound consists of at least one element selected from the group consisting of elemental metals, alloys, and intermetallic compounds, and at least one element selected from the group consisting of nitrogen, carbon, and oxygen. The elemental metals, alloys, and intermetallic compounds include at least one metallic element selected from the group consisting of Group IV elements, Group V elements, Group VI elements, aluminum, iron, silicon, cobalt, and nickel.

[0094] In the above description, the case where the cutting blade 100 has a base material 10 has been described, but the portion of the cutting blade 100 other than the tip portion 20 may also be formed from the same sintered body as the tip portion 20.

[0095] The embodiments disclosed herein should be considered exemplary in all respects, not limiting. The scope of the invention is set forth not by the embodiments described above, but by the claims, and is intended to include all modifications equivalent to and within the scope of the claims.

[0096] Explanation of reference numerals in the attached figures

[0097] 10: Substrate; 10a: Top surface; 10b: Bottom surface; 10c: Side surface; 10d: Mounting part; 11: Through hole; 20: Tool tip; 20a: Rake face; 20b: Backing face; 20c: Cutting edge; 21: Backing metal; 100: Cutting insert; S1: Powder preparation process; S2: Powder mixing process; S3: Sintering process.

Claims

1. A sintered body, wherein, The sintered body comprises diamond particles and a bonding material. The boron concentration in the diamond particles is above 0.001% by mass and below 0.9% by mass. The boron concentration in the bonding material is above 0.5% by mass and below 40% by mass.

2. The sintered body according to claim 1, wherein, The boron concentration in the diamond particles is above 0.005% by mass and below 0.1% by mass. The boron concentration in the bonding material is above 0.6% by mass and below 33% by mass.

3. The sintered body according to claim 1 or 2, wherein, The diamond particles have an average particle size of 0.1 μm or more and 50 μm or less. The proportion of diamond particles in the sintered body is above 80% by volume and below 99% by volume.

4. The sintered body according to claim 1 or 2, wherein, The bonding material comprises at least one selected from the group consisting of elemental metals, alloys, and intermetallic compounds. The elemental metal, the alloy, and the intermetallic compound comprise at least one metallic element selected from the group consisting of Group 4, Group 5, Group 6 elements of the periodic table, iron, aluminum, silicon, cobalt, and nickel.

5. The sintered body according to claim 1 or 2, wherein, The bonding material comprises at least one selected from the group consisting of compounds and solid solutions derived from said compounds. The compound is composed of at least one selected from the group consisting of elemental metals, alloys, and intermetallic compounds, and at least one selected from the group consisting of nitrogen, carbon, and oxygen. The elemental metal, the alloy, and the intermetallic compound comprise at least one metallic element selected from the group consisting of Group 4, Group 5, Group 6 elements of the periodic table, iron, aluminum, silicon, cobalt, and nickel.

6. The sintered body according to claim 1 or 2, wherein, The bonding material contains at least cobalt.

7. A cutting tool, wherein, The cutting tool has a cutting tip. The blade tip is formed from a sintered body according to any one of claims 1 to 6.

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