JPS61104045A - Diamond sintered body for tools - Google Patents

Abstract

PURPOSE:To obtain the diamond sintered body for tools having superior strength, wear resistance, and heat resistance, by forming a sintered body containing diamond, metal of group 4a, 5a, and 6a in the periodic table, iron group metal, and porosity in a specified volume ratio. CONSTITUTION:The powder consisting of diamond powder, a carbide or metal of group 4a, 5a, and 6a in the periodic table, and powder of iron group metal such as Fe, Co, and Ni, or further containing a boride is mixed uniformly. After partial graphitization of the diamond at a high temp. of >=about 1,300 deg.C, the mixture is sintered under stable conditions by a very high pressure and high temp. apparatus, and the sintered body is put into an acid such as aqua regia to eluate the iron group metal, to form porosity. In this way, the diamond sintered body for tools having the following composition can be obtained: >93-99vol% diamond content; the balance consisting of 0.1-3vol%, in total, of at least either the iron group metal or the metal or carbide of group 4a, 5a, and 6a in the periodic table, and of 0.5-7vol% porosity.

Description

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

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

These diamond sintered bodies are usually sintered using an iron group metal such as CG, which is a catalyst during diamond synthesis, as a binder, so when heated to a temperature of 600°C or higher, the diamond cracks. It has the disadvantage of becoming phytochemical and deteriorating. In order to improve the heat resistance of this diamond sintered body, Japanese Patent Application Laid-Open No. 53-11458
As described in No. 9, iron group metals such as Go, which promote graphitization of diamond during heating, may be removed.

However, when iron group metals such as CG 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 for a pit, strength, wear resistance, and heat resistance are required. ~ then,
Due to the lack of strength of the diamond sintered body, there was a drawback that the cutting edge would break and the life would be shortened. The inventors of the present invention previously proposed a diamond sintered body which has good strength, good wear resistance, and excellent heat resistance in JP-A No. 59-35066. This sintered body uses carbides from groups 4a and 58.6a of the periodic table as a binder to substantially reduce the pore content, 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 disclosed in JP-A No. 59-35066 has a small decrease in strength, 1
It has been found that at high temperatures exceeding 000°C, deterioration occurs due to the difference in thermal expansion between carbide and diamond. Therefore, in applications where the cutting edge is exposed to temperature A, such as in geothermal wells, 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 diamond sintered body for tools that has excellent strength and wear resistance.

[Means and effects for solving the L problem] The inventors of the present application conducted intensive research in order to obtain a diamond sintered body with even higher heat resistance, and as a result, the diamond content was 9.
It is more than 3% by volume and not more than 99% by volume, with the remainder being 4a and 5a of the periodic table.

6aM metal or carbide and/or iron group metal 0
．． 1 to 3 volume%, voids 0.5 volume% or more, 71FIfi
% or less, or containing 0.005 to 0.25% by volume of boron and/or boride, the heat resistance is further improved.
It was found that it has excellent wear resistance and strength.

To improve the heat resistance of diamond sintered bodies,
The iron group metal serving as the binder may be removed as shown in F=.

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, 0. There is a relationship between the strength and pores as shown in FIG. In other words, as the number of pores increases, the strength of the diamond sintered body decreases, but when the number of pores is 5% or more and 8% or less, the strength decreases rapidly, and when the vacancies are 8% or less, the rate of strength decrease is small. It will become. - In general, the strength required for a sintered body differs depending on its use, the strength of the workpiece, etc. For example, if the strength is 1.5 times or more than commercially available heat-resistant sintered diamond, the performance will be significantly improved for drilling relatively soft rocks or cutting ceramics. The pore content ffi must be at least 7% or less, and the sintered body must have a diamond content of 93% or more. If the pore content is less than 5% by volume, the strength of the diamond sintered body will be approximately three times that of commercially available heat-resistant diamond sintered bodies, making it suitable for drilling hard rocks and cutting high-hardness ceramics. Shows excellent performance and is desirable.

In the manufacturing method of this invention, the raw material diamond powder is
By heating the diamond powder 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, we can create a dense sintered product with a diamond content of over 93% by volume. However, if the diamond content exceeds 99% by volume, the iron group metal will be insufficient and it will not be possible to obtain a diamond sintered body with sufficient strength.

In the diamond sintered body of this invention, it is preferable that the content of pores be as small as possible, as shown in FIG. Metal is also required.

Therefore, in this invention there is a minimum of 0.5% by volume of vacancies.

The diamond powder used in the production of the diamond sintered body of this invention has an average maximum particle diameter of 40 to 60.
A high diamond content can be obtained by combining 30 to 40 volume percent of particle size a/2 and the remainder of particle size a/3 to a/1.000. preferable.

The diamond sintered body of the present invention contains diamonds of various particle sizes.
a, If group 5a metals or carbides are not contained, an abnormality of the iron group metal will occur especially near the fine die 1 = mondo particles, and if the metal is eluted, this part will become a void. Become. Therefore, if metal or carbide is contained, the strength will be further improved. The content m of the iron group metal and the metal or carbide of Groups 4a, 5a, and 6a 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 will become graphitized, resulting in a decrease in heat resistance. Also, it is preferable that this content be as low as possible, but 'A' in the diamond raw material? Since the iron group metals and the like that are present in the sintered body cannot be eluted in fact, the iron group metals and the like with a minimum of 0.1 fNit% will remain in the sintered body.

In the diamond sintered body of this invention, in particular, the carbide is W
C or has the same crystal v4 structure (Mo,
W) It is known that C has excellent toughness, wear resistance, and heat resistance.

Further, the sintered body of the present invention has a capacity of 0°005
When ~0.25% of boron and/or boride is contained, the properties are further improved. usually,
Diamond particles are sintered under ultra-high pressure and high temperature by the phenomenon of diamond dissolution or precipitation using a catalyst such as an iron group metal. 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. When the boron or boride content is less than 0.005%,
Formation of the diamond skeleton is slow. On the other hand, if the boron or boride content exceeds 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 diamond sintered body of the present invention can be either synthetic diamond or natural diamond.

In the @ sending method of this invention, the period tl blue 4th a.

5a, to contain a group 5a metal or carbide,
Diamond powder and Periodic Table 4a and 5a.

Group 6a carbides or metals as well as F8, 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. Instead of being mixed into the iron door metal in advance, it may be infiltrated by bringing it into contact with a member made of an iron group metal during sintering.

, Mana, the first application of the original patent application (1976 = 5188)
1), the periodic table Nos. 4a, 5a, 5a of the periodic table which mixes the pot and ball at the time of ball milling 4.
A sintered body of carbides of groups 44a, 5a, and 6a of the periodic table and metals of iron group is produced from the pot and ball at the same time as the diamond powder is ground in a ball mill. m5Kons mouth eaixatt with,
b"1llll'l・6 mixed powder 1.130
Diamond 1 is partially graphitized at a high temperature of 0° C. or higher, and then placed in an ultra-high pressure and high temperature device to sinter under conditions where the diamond is stable. It is necessary to sinter at a temperature higher than the temperature at which a eutectic liquid phase appears between the iron group metal and the compound such as carbide used at this time. 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.

In addition to pits, the diamond sintered body of this invention can be used as wire drawing dies, ceramic cutting tools,
Examples include dressers.

[Example 1 Hereinafter, this will be explained in detail using examples.

111 average grain a100μm, 50μm, 20μm and 5
~0.2 μι diamond powder was blended in a ratio of 5:3:1:1, and then ground and mixed for 5 minutes using a pot and ball made of W C-Co cemented carbide. 14 times this powder
After heating in a vacuum at a temperature of 00°C for 30 minutes, the powder was filled into an MO container, and a Co plate was placed on top of the finished powder to bring it into contact. 55 kb of was added, followed by heating to a temperature of 1460°C and holding for 10 minutes.

The fired i-shaped body obtained in this way was taken out from the container and the content of diamond, WC and co2 was measured by chemical analysis, and the content of diamond, WC and co
・Volume% was 3.35% by volume.

Next, this sintered body is placed in heated aqua regia to dissolve the co
The composition was investigated using a magnetic balance and chemical analysis.1
, diamond 96.5% by volume, wc.

0.14 volume%, Goo, 4 volume%, pores 2.96 volume [
It was 1%. When we measured the compressive strength of this sample, we found that
It showed a strength of 380 kg/a+n+2.

For comparison, the maximum diamond grain size is the same,
A sample with a diamond content of 92.0% by volume, pores of 7.7% by volume, and C'o0,3 volume II- was produced, and its compressive strength was measured and found to be 120 kg/mm'.

・ ・In a vacuum at 1200℃
When heated to 30 minutes and held for 30 minutes, no dimensional changes or cracks occurred.

Diamond particles with an average particle size of 11,180μ, 40μm, 15μl 83 and 0.5μ were blended in a ratio of 5:3:2:1. 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, and the resulting powder was 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.

After that, these diamond sintered bodies were
Cut it out to form a cube, and mark W and W on the steel body.
1 using a high-melting, high-point, high-hardness matrix made of a mixed powder of C+ Fe, Go, Ni, and Cu.
It was sintered and fixed at a temperature of 100°C to create a surface-set core pit.

For comparison, a core pit (indicated by symbol (Indicated by symbol Y in Table 1)
It was created.

Uniaxial compressive strength of 1600 to 2000 kg for samples A to X and Y shown in Table 1 above, respectively.
/ Cm' granite was excavated at 900 revolutions. The digging speed and life are shown in Table 2.

(L-A 1F Muhakuin Table 1 *1: Unit is state % *2: Carbides of metals in groups 48.5a and 6a of the periodic table *3
Diamond powder with an average particle size of 0.8μ and boron powder were ground and mixed using a wc-co cemented carbide pot and ball. This powder was mixed with diamond powder with an average particle size of 60 μm, 30 μm, and 10 μm in a ratio of 1:5:3.
55 kb, 1
Sintering was performed at 450°C. Analysis of this sintered body revealed that it was composed of 96.2% by volume of diamond, 3.45% by volume of Co, 0.1% Ni by volume, 2% by volume of WCo, and 0.05% by volume of boron. This was recognized. When this sintered body was treated in heated aqua regia, 3
．． 3% by volume of voids were created.

Using this sintered body, alumina ceramics with a Vickers hardness of 2300 was cut at a speed of 60 m/min and a depth of cut:
Cutting was performed using water-soluble cutting oil for 15 minutes at Q, 3 mm, feed: 0.05 mm/rotation.

For comparison, a commercially available heat-resistant diamond with 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 of this invention was 0.15
1111, whereas the flank wear width of commercially available heat-resistant diamond was 0.5811.

By changing the compounding ratio of diamond particles with different grain sizes and the graphitization treatment conditions, various diamond sintered bodies with a maximum grain size of 60 μ- and different diamond contents were created in the same manner as in Example 3. After that, I! A heat-resistant diamond sintered body was prepared by the treatment. Table 3 shows the diamond and pore contents of each sintered body.

(ysu Jinei Haku) f,・1 Each sintered body M-R shown in Table 3 was processed as a chip for cutting, and the compressive strength was 1000 to 1100 kg.
/c-2 andesite was wet-cut for 20 minutes at a cutting speed of 200 m/min, depth of cut = 1 m, feed: 0.31 m/rotation, and the flank wear width was measured.

The results are shown in Figure 2.

As is clear from Fig. 2, the flank wear width of samples M, N, O, and P, in which the pore volume is 7% by volume or less, is greater than that of samples Q, R, in which the pore volume is 7% by volume or more. It turns out that there are far fewer.

[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 the pressure line strength and the pore volume in a heat-resistant diamond sintered body from which the binder phase has been eluted. 2nd m is a diagram showing the andesite cutting test results of the heat-resistant die) almond sintered body. Patent Applicant: Sumitomo Electric Industries, Ltd. - No. 113] 7. Iyamo Doujin Party Tsumei Honchu Karate Shikaku Capacity Blue', /
,)$λ'm y>tH%) 241 4.6, r
is, Hrt,'l g, 11
. - Procedural amendment June 18, 1985 Dear Commissioner of the Patent Office, λ, 9゜q-] JfFQ
-・, 1, 1981 patent cicada number. No. 226574 No. 3, amended Author: Relationship with the Wappa case Patent applicant: Address 5-15, Kitahama, Higashi-ku, Osaka City Name (213) Tetsube Kawakami 4, Representative of Sumitomo Electric Industries, Ltd., Agent Address: Yachiyo Daiichi Building, 2-3-9 Tenjinbashi, Kita-ku, Osaka Telephone: Osaka (06) 351-6239 Name: Patent Attorney (6474) Kube Fukami 1-gu\ 5. Invention of riiata subject to amendment Detailed explanation column and Figures 1 and 2 of the drawings, page 6 - Positive contents ゛・(1) In lines 1 to 5 of page 12 of the specification [i.e., according to the increase in pores] . . . becomes smaller." In other words, as the number of pores increases, the strength of the Dai-Vmond sintered body decreases, but when the number of pores exceeds 3%, the strength decreases. The strength begins to decrease, and a sudden decrease in strength occurs between 4.5% and 8%, and the rate of strength decrease becomes small at 8% and above. "-'-"" In the sintered body of the invention, the iris is corrected in the container.・”・′
・、. " (3) □ Figure 1 of the drawings is corrected as shown in the attached sheet. (4) Figure 2 of the drawings is corrected as shown in the attached sheet.
"n)"xta4)'l'/l"2., JL
('b4 n ≦) 謬2fig wiping shout NO, M N OP Q R'z) L(1
z) 2.8 4.6,! ;, s 6.
& 77g, gr・

Claims (18)

[Claims] (1) The diamond content exceeds 93% by volume, and
9% by volume or less, with the remainder being 4a, 5a, and 6 of the periodic table.
Diamond for tools, characterized by comprising a total of 0.1 to 3% by volume of at least one of a group A metal or carbide and an iron group metal, and 0.5% to 7% by volume of voids. Sintered body. (2) The diamond content exceeds 95% by volume and is 99%
% by volume or less, and the remaining pores are 0.5% by volume or more and less than 5% by volume, the diamond sintered body for tools according to claim 1. (3) The carbides of groups 4a, 5a, and 6a of the periodic table are WC
Or, the diamond sintered body for tools according to claim 1 or 2, which is (MoW)C having the same crystal structure as WC. (4) The content of diamond is more than 93% by volume and not more than 99% by volume, and the remainder is a total of 0.1 to 0.1% or more of at least one of metals or carbides of Groups 4a, 5a, and 6a of the periodic table, or carbides, and iron group metals. 3% by volume, 0.5% to 7% by volume of voids, and a total of 0.005 to 0.25% by volume of at least one of boron and boride. body. (5) the diamond content exceeds 95% by volume;
9% by volume or less, and the remaining pores are 0.5% by volume or more5
The diamond sintered body for tools according to claim 4, wherein the diamond sintered body is less than % by volume. (6) The carbide of groups 4a, 5a, and 6a of the periodic table is W
The diamond sintered body for tools according to claim 4 or 5, which is C or (MoW)C having the same crystal structure as WC. (7) 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 from the periodic table. A total of at least one of the metals or carbides of Groups 4a, 5a, and 6a in Table 1 and the iron group metal is 0.
A method for manufacturing a diamond sintered body for tools, which has a volume of 1 to 3, and pores 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
The method for producing a diamond sintered body for tools according to claim 7 or 8, wherein the diamond sintered body is WC or (MoW)C having the same crystal structure as WC. (10) Create a mixed powder of diamond powder and an iron group metal, or a diamond powder and a metal or carbide of Groups 4a, 5a, or 6a of the periodic table and an iron group metal,
After graphitizing a portion of the diamond in the raw material powder at a temperature of 0°C or higher, a sintered body is created by hot pressing under high temperature and pressure at which the diamond is stable using an ultra-high pressure and high temperature equipment. The diamond content exceeds 93% by volume and is characterized by eluting iron group metals, metals of groups 4a, 5a, 6a of the periodic table, or part of carbides by acid treatment of the sintered body. % by volume or less, the balance being at least one of metals or carbides of Groups 4a, 5a, and 6a of the periodic table and iron group metals in total of 0.1 to 3% by volume, and vacancies of 0.5% by volume or more A method for manufacturing a diamond sintered body for tools comprising 7% by volume or less. (11) The tool according to claim 10, wherein the diamond content is more than 95% by volume and less than 99% by volume, and the remaining pores are 0.5% by volume or more and less than 5% by volume. A method for producing a diamond sintered body for use. (12) The carbides of Groups 4a, 5a, and 6a of the periodic table are WC or (MoW)C having the same crystal structure as WC.
A method for manufacturing a diamond sintered body for tools according to claim 10 or 11. (13) Mixed powder of diamond powder and boron or boride, or diamond powder and periodic table items 4a and 5
A, a mixed powder of group 6a metals or carbides, iron group metals, and boron or borides is prepared, and a part of the diamond in the raw material powder is graphitized at a temperature of 1300°C or higher, and iron group metals or periodic rule metals are graphitized. After contacting the sintered carbides of Groups 4a, 5a, and 6a in Table 1, a sintered body is created by hot pressing under high temperature and pressure at which diamond is stable using an ultra-high pressure and high temperature device. Diamond content is 93%, 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 an acid.
more than 99% by volume, the balance being at least one of metals or carbides of Groups 4a, 5a, and 6a of the periodic table and iron group metals in total of 0.1 to 3% by volume, boron or At least one of the borides in total from 0.005 to 0
．． A method for manufacturing a diamond sintered body for tools, which has pores of 25% by volume and 0.5% by volume or more and 7% by volume or less of pores. (14) the diamond content exceeds 95% by volume;
14. The method for manufacturing a diamond sintered body for tools according to claim 13, 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. (15) The carbide of groups 4a, 5a, and 6a of the periodic table has WC or the same crystal structure as WC (MoW)
The diamond sintered body for tools according to claim 13 or 14, which is C. (16) 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 pressure using an ultra-high-pressure/high-temperature device, and the sintered body is acid-treated to produce iron group metals, 4a of the periodic table.
, a diamond content of more than 93% by volume, characterized by eluting a portion of metals or carbides of Groups 5a and 6a and at least one of boron and borides;
% by volume or less, and the remainder is from periodic table 4a, 5a, 6a
A total of 0.1 to 3% by volume of at least one of group metals or carbides and iron group metals, a total of 0.005 to 0.25% of at least one of boron and borides, and 0 vacancies.
．． A method for manufacturing a diamond sintered body for tools comprising 5% by volume or more and less than 7% by volume. (17) The diamond content is more than 95% by volume and less than 99% by volume, and the remaining pores are 0.5% by volume or more and less than 5% by volume. A method for manufacturing a diamond sintered body for tools. (18) 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 a tool according to claim 16 or 17, wherein the diamond sintered body is C.