JPS6355161A - Manufacture of industrial diamond sintered body - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a diamond sintered body used in various tools such as cutting tools, drilling tools, and wire drawing dies.

[Prior Art] Currently, sintered bodies for tools with a diamond content of 70% by volume or more and diamond particles bonded to each other are on sale. These sintered bodies are used for cutting nonferrous metals, plastics, or ceramics, as dressers, drill bits, or wire drawing dies. In particular, when these diamond sintered bodies are used as dies for cutting non-ferrous metals or drawing relatively soft wire materials such as copper wires, the performance is very excellent.

These diamond sintered bodies are usually sintered using an iron group metal such as Go, which is a catalyst during diamond synthesis, as a binder, so when heated to a temperature of 600°C or higher, the diamond It has the disadvantage of becoming graphitized and deteriorating. In order to improve the heat resistance of this diamond sintered body, Japanese Patent Application Laid-Open No. 53-1145
As described in No. 89, iron group metals such as CO, which promote graphitization of diamond during heating, may be removed.

However, when iron group metals such as Go are leached from the diamond sintered body, the strength of the diamond sintered body is approximately 20%.
~30% decrease. In particular, when a diamond sintered body is used as a bit, strength, wear resistance, and heat resistance are required. However, due to the lack of strength of the diamond sintered body, the cutting edge was damaged and the service life was shortened.

The inventors of the present application previously proposed in Japanese Patent Application Laid-Open No. 59-35066 a method for producing a diamond sintered body having excellent strength, good wear resistance, and further excellent heat resistance. This sintered body uses carbides from groups 4a, 5a, and 6a of the periodic table as a binder to substantially reduce the content of pores, thereby suppressing the decrease in strength of the sintered body due to Co elution. That is.

[Problems to be Solved by the Invention] However, although the diamond sintered body obtained by the method disclosed in JP-A No. 59-35066 does not have much strength loss, it forms carbides at high temperatures exceeding 1000°C. It was found that deterioration occurs due to the difference in thermal expansion between diamond and diamond.

Therefore, in applications where the cutting edge is exposed to high temperatures, such as geothermal well drilling, it has not yet been fully satisfactory.

Therefore, the object of this invention is to further improve heat resistance,
Another object of the present invention is to provide a manufacturing method capable of producing a diamond sintered body for tools having excellent strength and wear resistance.

[Means for solving the problem] The invention of T41 creates a diamond powder or a mixed powder of diamond powder and a metal or carbide of Groups 4a, 5a, or 6a of the periodic table and an iron group metal, and
A part of the diamond in the raw material powder is graphitized at a temperature of ℃ or higher, and then iron group metals or diamonds 4a and 5 of the periodic table are graphitized.
By bringing it into contact with a sintered carbide of groups A and 6a and hot-pressing it under high temperature and pressure conditions where the diamond is stable using an ultra-high pressure and high temperature device, a sintered body is created, and the sintered body is treated with an acid. The diamond content is more than 93% by volume and not more than 99% by volume, and the remainder is from the periodic table. For tools, consisting of at least one of metals or carbides from Groups 4a, 5a, and 6a in the table and iron group metals in a total of 0°1 to 3% by volume, and 0.5% to 7% by volume of voids. This is a method for manufacturing a diamond sintered body.

The second invention is a combination of diamond powder and iron group metals, or diamond powder and items 4a and 5a of the periodic table.

A mixed powder of group 6a metals or carbides and iron group metals is created, a portion of the diamond in the raw material powder is graphitized at a temperature of 1300°C or higher, and then the diamond is heated using an ultra-high pressure and high temperature device. A sintered body is created by hot pressing under stable high temperature and high pressure, and the sintered body is treated with acid to elute iron group metals, metals of groups 4a, 5a, and 6a of the periodic table, or some of the carbides. The diamond content is more than 93% by volume and not more than 99% by volume, and the remainder is a total of at least one of metals or carbides of groups 4a, 5a, and 6a of the periodic table and iron group metals. 0
．． This is a method for producing a diamond sintered body for tools, which has pores of 1 to 3% by volume, and 0.5% to 7% by volume of pores.

The third invention is a mixed powder of diamond powder and boron or a boride, or a diamond powder and a powder found in the periodic table 4.
A mixed powder of a, 5a, and 6a group metal or carbide, iron group metal, and boron or boride is prepared, and 1300
After graphitizing a part of the diamond in the raw material powder at a temperature of ℃ or higher and bringing it into contact with iron group metals or sintered carbides of groups 4a, 5a, and 6a of the periodic table, using an ultra-high pressure and high temperature device, By creating a sintered body by hot pressing under high temperature and high pressure where the diamond is stable, and acid-treating the sintered body,
Iron group metals, Periodic Table 4a and 5a.

characterized by eluting a portion of Group 6a metals or carbides and at least one of boron and borides;
The diamond content is more than 93% by volume and not more than 99% by volume, and the balance is at least one of metals or carbides of Groups 4a, 5a, and 5a of the periodic table and iron group metals in a total of 0.1 to 3 % by volume, at least one of boron or boride in total from 0.005 to 0.25 vol. %, and voids of 0.5 vol. % or more and 7 vol. % or less. .

A fourth invention is a mixed powder of diamond powder, an iron group metal, and at least one of boron and borides, or a diamond powder, a metal or carbide of Groups 4a, 5a, and 6a of the periodic table, an iron group metal, and A mixed powder with at least one of boron and boride is prepared, and 1300
A part of the diamond in the raw material powder is graphitized at a temperature of ℃ or higher, and then hot-pressed using an ultra-high pressure/high temperature device under high temperature and pressure at which the diamond is stable, to create a sintered body. Diamond content is 93 capacity, characterized by eluting iron group metals, metals or carbides of groups 4a, 5a, 6a of the periodic table, and at least one of boron and borides by treating with acid. % and 99% by volume or less, and the remainder is from Periodic Table 4a and 5a.
, a total of 0.1 to 3% by volume of at least one of Group 6a metals or carbides, and iron group metals, and a total of 0.005 to 0.25% by volume of at least one of boron and borides.
, a method for manufacturing a diamond sintered body for tools, which has pores of 0.5% by volume and less than 7% by volume.

[Description of Means] The inventors of the present application have conducted intensive research in order to obtain a diamond sintered body with even higher heat resistance, and as a result, the diamond content is more than 93% by volume and less than 99% by volume,
The rest are Periodic Table 4a and 5a.

Group 6a metals or carbides and/or iron group metals 0
．． A diamond sintered body consisting of 1 to 3% by volume and 0.5% to 7% by volume of voids, or containing 0.005 to 0.25% by volume of boron and/or boride, is heat resistant. It has been found that this material has further improved properties, and has excellent abrasion resistance and strength.

In order to improve the heat resistance of the diamond sintered body, as described above, the iron group metal serving as the binder may be removed. However, the locations where the binder was present become voids due to the removal of the iron group metal. By the way, in a diamond sintered body, the relationship shown in FIG. 1 exists between its strength and pores. In other words, as the number of pores increases, the strength of the diamond sintered body decreases, but the strength begins to decrease when the number of vacancies is 3%, and 4%.
, a sudden decrease in strength occurs between 5% and 8%, and 8%
Above this, the rate of decrease in strength becomes small.

Generally, the strength required for a diamond sintered body differs depending on its use, the strength of the workpiece, etc.

For example, if the strength is at least 1.5 times that of commercially available heat-resistant sintered diamond, the performance will be significantly improved when drilling relatively soft rocks or cutting ceramics. Therefore, for such uses, the pore content must be at least 7% or less, and a sintered body with a diamond content of 93% by volume or more is required. If the pore content is less than 5%, the strength of the diamond sintered body is approximately three times that of commercially available heat-resistant sintered diamond, and it has excellent performance in drilling hard rocks and cutting high-hardness ceramics. is desirable.

In the manufacturing method of this invention, the raw material diamond powder is
Dense sintering with a diamond content of over 93% by volume is achieved by heating at a high temperature of 00℃ or higher to graphitize the surface of the diamond powder, and by using a mixture of diamond powders with different particle sizes as raw materials. It is said that it is possible to obtain a body. However, when the diamond content exceeds 99% by volume, iron group metals become insufficient and a diamond sintered body with sufficient strength cannot be obtained.

In the diamond sintered body obtained by the manufacturing method of the present invention, as shown in FIG. 1, it is preferable that the content of pores be as small as possible, but a sintered body with high strength can be obtained. As mentioned above, iron group metals are also required.

Therefore, in the diamond sintered body obtained according to the present invention, pores exist at a minimum of 0.5% by volume.

The diamond powder used in the method for producing a diamond sintered body of the present invention has an average maximum particle diameter of 40 to 40.
A mixture of 60% by volume and 30 to 40% by volume of particles having a particle size of a/2 and the remainder having a particle size of a/3 to a/1000 is preferable because a high diamond content can be obtained.

The diamond sintered body obtained by the manufacturing method of the present invention contains diamonds of various particle sizes, but when it does not contain metals or carbides of Groups 4a, 5a, and 5a of the periodic table, diamonds of various particle sizes are contained. In particular, when an abnormal accumulation of iron group metal occurs near fine diamond particles and the metal is eluted, this area becomes a pore. However, if metal or carbide is included, the strength will be further improved.

The content of the iron group metal and the metal or carbide of Groups 4a, 5a, and 5a of the periodic table is preferably 0.1 to 3% by volume. If this content exceeds 3% by volume, cracks will occur due to the difference in thermal expansion with diamond, and diamond graphitization will occur, resulting in a decrease in heat resistance. Further, it is preferable that this content be as small as possible, but since it is virtually impossible to elute iron group metals remaining in the diamond raw material, the minimum content is 0. 1% by volume of iron group metals will remain in the sintered body.

The diamond sintered body obtained by the production method of the present invention has excellent toughness, wear resistance, and heat resistance, especially when the carbide is WC or (Mo, W)C having the same crystal structure. I know.

Furthermore, the sintered body obtained by the manufacturing method of the present invention has
When 0.005 to 0.25% by volume of boron and/or boride is contained, the properties are further improved. Generally, diamond particles are sintered under ultra-high pressure and high temperature by dissolving diamond with a catalyst such as an iron group metal or by a precipitation phenomenon. When at least one of boron and borides is added, borides of iron group metals are formed, which lowers the melting point and increases the melt deposition rate, which causes the bonding parts between diamond particles (diamond skeleton parts) to grow. It can be inferred that the holding power of the diamond particles was improved. Boron or boride content is 0.00
Below 5%, the formation of the diamond skeleton is slow. On the other hand, the boron or boride content is 0°25
%, a large amount of boron will enter the diamond skeleton, reducing the strength of the diamond skeleton.

The diamond powder used in the manufacturing method of this invention can be either synthetic diamond or natural diamond.

In the manufacturing method of the present invention, the periodic table 4a.

In order to contain metals or carbides of groups 5a and 6a,
Diamond powder and Periodic Table 4a and 5a.

Group 6a carbides or metals as well as Fe, Co.

An iron group metal powder such as Ni or a powder obtained by adding boron or boride to the powder is uniformly mixed using a means such as a ball mill. Without pre-mixing this iron group metal, during sintering,
Infiltration may be carried out by contacting a member made of an iron group metal.

Furthermore, as disclosed in the inventors' earlier application (Japanese Patent Application No. 52-51881), the pot and balls used in ball milling can be mixed with carbides of groups 4a, 5a, and 6a of the periodic table. A sintered body of iron group metal is prepared, and at the same time diamond powder is ground in a ball mill, a sintered body of carbide of groups 4a, 5a, and 6a of the periodic table consisting of a pot and balls and an iron group metal is prepared. A method of mixing fine powder may also be adopted.

The mixed powder is heated to a high temperature of 1300°C or higher to partially graphitize the diamond, and then placed in an ultra-high pressure/high temperature device.
Diamond is sintered under stable conditions. It is necessary to sinter at a temperature higher than the temperature at which a eutectic liquid phase appears between the iron group metal used at this time and a compound such as a carbide. The diamond sintered body thus produced is placed in an acid capable of corroding iron group metals, such as aqua regia, to elute iron group metals and form pores.

Applications of the diamond sintered body obtained by the manufacturing method of the present invention include, in addition to bits, wire drawing dies, ceramic cutting tools, dressers, and the like.

[Example] Hereinafter, this will be explained in detail using examples.

Example 1 Average particle size 100 μm 150 μm 120 μm and 5-0
．． Diamond powder of 2 μm was mixed in a ratio of 5:3:1:1, and then ground and mixed for 5 minutes using a pot and ball made of WC-Co cemented carbide. This powder was heated to 1400℃
After heating in vacuum for 30 minutes at a temperature of C, it was filled into a Mo container.

The plate was placed on the finished powder and brought into contact with it, and using an ultra-high pressure/high temperature device, a pressure of 55 kb was first applied, and then a pressure of 1460 kb was applied.
℃ and held for 10 minutes. The sintered body thus obtained was taken out of the container and the content of diamond, WC and Co was measured by chemical analysis.
96°5 volume%, 0.15 volume%, 3.35 respectively.
It was %.

Next, this sintered body was placed in heated aqua regia to elute Co, and the composition was investigated using a magnetic balance and chemical analysis.
O, 4% by volume, 2.96 pores by volume, 96%. When the compressive strength of this sample was measured, it was found to be 380 kg/mm2.

For comparison, the maximum diamond grain size is the same,
A sample with a diamond content of 92.0% by volume, 7.7% by volume of voids, and 3% by volume of CoO was produced, and its compressive strength was measured and found to be 120 kg/mm2.

Next, in order to test the heat resistance of this sintered body, it was heated to 1200° C. in vacuum and held for 30 minutes, and no dimensional changes or cracks occurred.

Example 2 Average particle size 80 μm 140 μm 115 μm and 0.5 μm
m diamond particles were blended in a ratio of 5:3:221. This powder was mixed with various iron group metals shown in Table 1 and metals or carbides of Groups 4a, 5a, and 6a of the periodic table to form a finished powder, which was then filled into a container made of Ta. Similarly, sintering was performed under the conditions of 58 kb and 1500°C. Each of the sintered bodies thus obtained was taken out of the Ta container and treated in heated aqua regia. Next, the pore content of the sintered body was measured. The results are also shown in Table 1.

(Left below) After that, these diamond sintered bodies were
Cut it into a cube of m, and mark W, W on the steel body.
A high-melting-point, high-hardness matrix made of a mixed powder of C, Fe, Co, Ni, and Cu was sintered and fixed at a temperature of 1100° C. to create a surface-set core pit.

For comparison, a core pit made from a commercially available sintered body made of diamond particles of 40 to 60 μm (indicated by X in Table 1) and a core pit made from a sintered body made using natural diamond (denoted by X in Table 1) were used. (indicated by symbol Y in Table 1) was created.

For samples A to L, X and Y shown in Table 1 above, the uniaxial compressive strength is 1600 to 2000 kg/
cm2 granite was drilled at 900 rpm. The digging speed and life are shown in Table 2.

(Margin below) Table 2 Example 3 Diamond powder with an average particle size of 0.8 μm and boron powder were ground and mixed using a We-Co [hard metal pot and ball]. This powder and the average particle size of 60 μm and 30 μm
and 10 μm diamond powder, 1:5:3:
Mix at a ratio of 1:1 and then heat in vacuum at a temperature of 1450°C for 1 hour to obtain 55 kb,
Sintering was performed at 1450°C. Analysis of this sintered body revealed that it contained 96.2% diamond by volume and C03°45
It was confirmed that the sintered body contained 0.1% by volume of Ni, 2% by volume of WCo, and 0.05% by volume of boron. When this sintered body was treated in heated aqua regia, 3
．． 3% by volume of voids were created.

Using this sintered body, cut alumina ceramics with a Vickers hardness of 2300 at a cutting speed of 260 m/min and a depth of cut of 0.3.
mm, feed: 0.05 mm/rotation, and cutting was carried out for 15 minutes using water-soluble cutting oil.

For comparison, commercially available heat-resistant diamond having a particle size of 40 μm to 60 μm and 8% by volume of pores was used for cutting.

As a result, the flank wear width of the sintered body obtained by the production method of the present invention was 0.15 mm, whereas the flank wear width of the commercially available heat-resistant diamond was 0.58 mm.

Example 4 Various diamond sintered bodies with a maximum particle size of 60 μm and different diamond contents were created in the same manner as in Example 3 by changing the blending ratio of diamond particles with different particle sizes and the graphitization treatment conditions. After that, acid treatment was performed to prepare a heat-resistant diamond sintered body. Table 3 shows the diamond and pore contents of each sintered body.

(Left below) Each of the sintered bodies M...R shown in Table 3 was processed as a chip for cutting, and the compressive strength was 1000 to 1100.
kg/cm2 of andesite was cut wet for 20 minutes at a cutting speed of 200 m/min, depth of cut: 1 mm, feed: 0.3 mm/rotation, and flank wear width was measured. The results are shown in FIG.

As is clear from Fig. 2, for samples M, N, O, and P, in which the pore area is 7% by volume or less, the flank wear width is
It can be seen that the number of pores is much smaller than that of Samples Q and R, which have 7% by volume or more.

Example 5 Average particle size 50 μm, 25 μm, 10 μm and 0.5 μm
m of diamond powder, 55:30:10:5
mixed in the ratio of This diamond powder and transition metals of Groups 4a, 5a, and 6a of the periodic table were blended in the proportions shown in Table 4, mixed, and then heated in vacuum at 1500° C. for 30 minutes to obtain a finished powder.

After filling this finished powder into an MO container in the same manner as in Example 1, a Co plate was placed on top of the finished powder, and the pressure was 50 kb.
- Sintered at a temperature of 1500°C for 15 minutes.

Table 5 shows the results of analysis of these sintered diamonds after they were taken out of the MO container and the results of analysis after placing them in aqua regia for 100 hours to elute the metal.

Next, using the sintered diamond treated with aqua regia, an alumina round bar with a Vickers hardness of 2300 was cut at a cutting speed of 80 m/s.
minute, depth of cut 0.2mm, feed 0. 30 at 1mm/rotation
Cut for a minute. The flank wear width at this time is also shown in Table 5.

(The following is a blank space) Example 6 0.7 μm diamond powder and boron powder were blended in the proportions shown in Table 6. These powders were mixed for 30 minutes using a cemented carbide pot and ball, and this powder and particle size 50
After mixing diamond powders of μm, 25 μm, and 6 μm in the ratio of 5:50:30:15,
℃ for 10 minutes in a vacuum of 10 −5 torr.

Next, these finished powders were sintered in the same manner as in Example 1, and then the container was removed. Add these sintered bodies to aqua regia for 150 min.
The metal was eluted over time, and the results of the analysis were then analyzed in the 6th test.
Shown in the table. Using these sintered diamonds, a pressureless sintered silicon nitride round bar with a Vickers hardness of 1700 was cut at a cutting speed of 100 m/min, depth of cut of 0.2 mm, and feed of 0.03.
Dry cutting was performed at mm/rotation for 20 minutes. This result is also the 6th
Shown in the table.

(The following is a blank space) [Effects of the Invention] As described above, according to the present invention, it is possible to obtain a diamond sintered body for tools with further improved heat resistance, strength, and wear resistance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between compressive strength and pore volume in a heat-resistant diamond sintered body from which the binder phase has been eluted. FIG. 2 is a diagram showing the results of an andesite cutting test on a heat-resistant diamond sintered body. Foil 1 diagram

Claims (12)

[Claims] (1) Create diamond powder or a mixed powder of diamond powder and metals or carbides of Groups 4a, 5a, and 6a of the periodic table and iron group metals, and heat the diamond powder in the raw material powder at a temperature of 1300°C or higher. Part of it is graphitized,
After that, it is brought into contact with an iron group metal or a sintered carbide of Groups 4a, 5a, and 6a of the periodic table, and hot-pressed using an ultra-high pressure and high temperature device under high temperature and pressure at which the diamond is stable, to create a sintered body. , by acid-treating the sintered body,
The diamond content is more than 93% by volume and not more than 99% by volume, and the remainder is periodic. At least one of the metals or carbides of Groups 4a, 5a, and 6a of the Table of Contents and the iron group metal is contained in a total of 0.
1 to 3% by volume, and 0.5% to 7% by volume of voids
A method for manufacturing a diamond sintered body for tools, comprising: (2) the diamond content exceeds 95% by volume;
9% by volume or less, and the remaining pores are 0.5% by volume or more5
The method for producing a diamond sintered body for a tool according to claim 1, wherein the amount of the diamond sintered body is less than % by volume. (3) The carbide of groups 4a, 5a, and 6a of the periodic table is
The method for producing a diamond sintered body for tools according to claim 1 or 2, wherein the diamond sintered body is WC or (MoW)C having the same crystal structure as WC. (4) A mixed powder of diamond powder and an iron group metal, or a mixed powder of diamond powder and a metal or carbide of groups 4a, 5a, or 6a of the periodic table and an iron group metal is prepared, and
After graphitizing a portion of the diamond in the raw material powder at a temperature of ℃ or higher, a sintered body is created by hot-pressing the diamond under high temperature and pressure using an ultra-high pressure and high temperature device, and the sintered body is Diamond content is 9, characterized by eluting iron group metals, metals from groups 4a, 5a, and 6a of the periodic table, or part of carbides by treating the aggregate with acid.
more than 3% by volume and not more than 99% by volume, the balance being a total of 0.1 to 3% by volume of at least one of metals or carbides of groups 4a, 5a, and 6a of the periodic table and iron group metals, and vacancies. A method for manufacturing a diamond sintered body for tools comprising 0.5% by volume or more and 7% by volume or less. (5) the diamond content exceeds 95% by volume;
5. The method for producing a diamond sintered body for tools according to claim 4, wherein the pores are 99% by volume or less, and the remaining pores are 0.5% by volume or more and less than 5% by volume. (6) The carbide of groups 4a, 5a, and 6a of the periodic table is W
The method for producing a diamond sintered body for a tool according to claim 4 or 5, wherein the diamond sintered body is C or (MoW)C having the same crystal structure as WC. (7) Mixed powder of diamond powder and boron or boride, or diamond powder and periodic table items 4a and 5a
, a mixed powder of a group 6a metal or carbide, an iron group metal, and boron or a boride is created, and a part of the diamond in the raw material powder is graphitized at a temperature of 1300 ° C. or higher,
After contacting iron group metals or sintered carbides of groups 4a, 5a, and 6a of the periodic table, a sintered body is created by hot pressing at high temperatures and pressures where diamond is stable using ultra-high pressure and high temperature equipment. and by treating the sintered body with acid, at least a portion of iron group metals, metals or carbides of groups 4a, 5a, and 6a of the periodic table, and boron and borides are eluted. The content is more than 93% by volume and not more than 99% by volume, and the remainder is from periodic table 4a,
A total of 0.1 to 3% by volume of at least one of a group 5a or 6a metal or carbide and an iron group metal, a total of 0.005 to 0.25% by volume of at least one of boron or a boride, and vacancy. A method for manufacturing a diamond sintered body for tools having holes of 0.5% by volume or more and 7% by volume or less. (8) the diamond content exceeds 95% by volume;
9% by volume or less, and the remaining pores are 0.5% by volume or more5
8. The method for producing a diamond sintered body for tools according to claim 7, wherein the amount of the diamond sintered body is less than % by volume. (9) The carbide of groups 4a, 5a, and 6a of the periodic table is
WC or (MoW)C with the same crystal structure as WC
A method for manufacturing a diamond sintered body for tools according to claim 7 or 8. (10) A mixed powder of diamond powder and an iron group metal and at least one of boron and borides, or a mixed powder of diamond powder and a metal or carbide of Groups 4a, 5a, or 6a of the periodic table, an iron group metal, and boron and boron. Create a mixed powder with at least one of the compounds, graphitize a part of the diamond in the raw material powder at a temperature of 1300 ° C. or higher,
Thereafter, a sintered body is created by hot-pressing the diamond under high temperature and high pressure using an ultra-high pressure/high temperature device, and the sintered body is treated with an acid to produce iron group metals, 4a of the periodic table,
The diamond content is more than 93% by volume and not more than 99% by volume, and the remainder is in the periodic table. A total of 0.1 to 3% by volume of at least one of metals or carbides of groups 4a, 5a, and 6a and iron group metals, a total of 0.005 to 0.25% by volume of at least one of boron and borides, A method for manufacturing a diamond sintered body for tools, comprising 0.5% by volume or more and less than 7% by volume of pores. (11) The diamond content is more than 95% by volume and less than 99% by volume, and the remaining pores are more than 0.5% by volume and less than 5% by volume, according to claim 10. A method for manufacturing a diamond sintered body for tools. (12) The carbide of groups 4a, 5a, and 6a of the periodic table has WC or the same crystal structure as WC (MoW)
The method for manufacturing a diamond sintered body for tools according to claim 10 or 11, wherein the diamond sintered body is C.