JPS6369760A - Sintered body for high hardness tools and its manufacturing method - 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] Cubic boron nitride (Cubic El, hereinafter abbreviated as OBN) is a substance with the second highest hardness after diamond, and is synthesized under ultra-high pressure and high temperature. Currently, it is already being used as abrasive grains for grinding, and for cutting purposes (sintered bodies made by bonding 3BN with metal Co, etc.) are used in some cases.Sintered bodies made by bonding this OBN with metal When used as a cutting tool,
There are disadvantages such as a decrease in wear resistance due to the softening of the bonding metal phase at high temperatures, and damage to the tool because the metal to be stiffened is easily welded. The present invention is not a sintered body bonded with such metals, but a new OBN suitable for tool applications such as cutting tools that uses a hard metal compound as a binder phase with high strength and excellent heat resistance.
This relates to a sintered body.

When viewed as a tool material, CBN is characterized by high hardness and extremely high thermal conductivity. Taking a cutting tool as an example, if other conditions are the same, the higher the thermal conductivity of the tool material, the lower the temperature at the cutting edge during cutting, which is advantageous for tool wear. Furthermore, when intermittent cutting such as milling is performed, thermal shocks due to heating and rapid cooling are applied to the tool, which causes thermal cracks. Even in this case, if the thermal conductivity of the tool is high, the difference in temperature between the tool surface and the inside will be small, making it difficult for cracks to occur. Taking advantage of these excellent characteristics of OBN, the inventors developed a composite sintering method of OBN and various heat-resistant compounds in order to obtain a high-strength sintered body required for tools such as cutting tools. created a body.

The properties required of a heat-resistant compound to obtain the desired composite sintered body are first of all high strength, and when made into a composite sintered body, the above-mentioned characteristic of OBN, which has high thermal conductivity, must be met. The heat-resistant compound used in combination to maintain the temperature is also required to have high thermal conductivity. Examples of such heat-resistant compounds include carbides, nitrides, borides, silicides, and mixtures of transition metals of groups 4a, 5a, and 6a of the periodic table, or mutual solid solution compounds thereof. What these compounds have in common is that they have high hardness, high melting point, and reed, and these compounds also have metallic physical properties compared to oxides. In particular, the thermal conductivity of these compounds is close to that of metals. Al and Ol have excellent properties among oxides in terms of heat resistance and strength, and have relatively high thermal conductivity near room temperature, but as shown in Figure 1, they have excellent thermal conductivity at high temperatures. Thermal conductivity decreases significantly. This is a major drawback in applications such as cutting tools where properties at high temperatures are a problem.

On the other hand, many of the compounds described above have rather high thermal conductivity at high temperatures, as shown in FIG. The method for manufacturing a composite sintered body of the heat-resistant compound and OBN selected in this way is to first mix OBN powder and one or more of the heat-resistant compound powders using a means such as a ball mill. This is then molded into powder form or molded into a predetermined shape at room temperature, and then subjected to high pressure using an ultra-high pressure device.
Sinter under high temperature. The ultra-high pressure equipment used is a girdle type, belt type, etc. equipment used for diamond synthesis.

A graphite cylinder is used as the heating element, and talc and Na0t are placed inside it.
The OEM mixed powder embossing body is wrapped with an insulating material such as the following. A pressure medium such as Pi-O7 Elite is placed around the graphite heating element. It is desirable that the pressure and temperature conditions for sintering be within the stability region of cubic boron nitride shown in Figure 2, but this equilibrium line is not always known accurately and is only a guideline. .

Although the conditions can be changed depending on the type of heat-resistant compound to be combined with OBN, a pressure of 20% is required to obtain the desired sintered body.
It is necessary to sinter under high pressure and high temperature at a temperature of 700° C. or higher.

A very noteworthy feature of the sintered body according to the invention, which makes the invention useful, is that the heat-resistant compound forms a continuous phase on the structure of the sintered body. That is, in the sintered body of the present invention, the tough heat-resistant compound is as if we-
〇〇 Like the metallic Co phase, which is the binder phase in the cemented carbide, it penetrates into the gaps between the high-hardness OBN particles and forms a continuous binder phase, which gives the sintered body toughness. It was given to us. As a result of experiments, it has become clear that in order to obtain a sintered body having such a structure, the OEM content needs to be 80% or less by volume. The lower limit of the amount of CBB phase in the sintered body according to the present invention is up to 20 parts by volume. If it is less than this, the performance as a tool that takes advantage of the OEM characteristics will not be exhibited. In addition, when used as a tool for cutting high hardness materials such as chilled rolls, the OB in the sintered body
It is desirable that the amount of N phase is 40 or more by volume;
The amount of BN phase is shown in a microscopic photograph magnified 1500 times. In the figure, a binder phase mainly composed of TiN, which appears as a white phase, penetrates into the gaps between the OBN particles, which appear as black, to form a dense sintered body. The reason for such a structure is considered to be that TiN, which is relatively easily deformed compared to OBN at high temperatures, penetrates between OBN particles during sintering.

Considering the use as a tool, the binder phase heat-resistant compound of OBN of the sintered body of the present invention is a transition metal belonging to Group 4a of the periodic table, ie, Ti, zr.

Particularly preferred are carbides, nitrides and solid solution compounds of these with each other, or carbides of W in group 6a of the periodic table, we. These are currently used for cutting tools etc.
It is a compound with excellent wear resistance and high strength, and is used as a hard wear-resistant component of c-based cemented carbide cermet.

Another reason why carbides, nitrides, and their mutual solid solutions of Ti, Zr, and Hf are excellent as the binder phase heat-resistant compound of the present invention is that, taking nitrides as an example, nitrides of these metals are (M is Ti, Zr, Hf
, and X means the presence of atomic vacancies or a relative excess of atoms. ), has a wide existence range on the M-N phase diagram. As a result of trial production of sintered bodies using MNlb with various X values as raw materials for the sintered bodies, it was found that the sintering properties were excellent in percentage within a certain range of the value of X. The reason for this will be discussed below.

When considered as a tool material, particularly in a cutting tool, the crystal grain size of the sintered body is preferably several microns or less.

Micron or sub-micron fine powder contains a large amount of oxygen. Generally, most of this oxygen exists on the powder surface in the form of a compound similar to hydroxide. This hydroxide-like compound decomposes when heated and comes out as a gas. When the material to be sintered is not sealed, it is not difficult to get this gas out of the system. However, when sintering is carried out under ultra-high pressure as in the present invention,
It is almost impossible for the generated gas to escape outside the heating system. Generally, in such cases, it is common knowledge in the powder metallurgy industry to perform a degassing treatment in advance, but this poses a problem if the degassing temperature cannot be raised sufficiently. This case corresponds to exactly that. That is, when considering the transformation of CBN into a low pressure phase, there is an upper limit to the heating temperature.

The degassing process of fine powder involves the following stages depending on the temperature. First, at low temperatures, physically adsorbed substances and hygroscopic water are removed. Decomposition of chemisorbed substances and hydroxides then occurs. At the end, oxide remains.

(In the case of 3EN, it is stable up to about 1000°C, so it can be heated to at least this temperature in advance.

Therefore, it can be considered that if the gas is degassed and heated in advance, the residual gas components remain in the form of oxides. Conversely, since it is desired that gas components remain in the sintered body as little as possible, it is preferable to remove all water and hydrogen as a preliminary treatment.

In the present invention, all degassing treatments at temperatures of 1000° C. or higher are performed in vacuum based on this idea. The reason why a good sintered body can be obtained when 1bc is added is considered to be as follows.

In other words, there is oxide on the surface of the OEM powder, probably B! 03 type exists.

When this B, 03 reacts with M corresponding to the (-X) part of 1f=x, it does not generate a concentration gas such as B2O3+ 4M - + MEN + 3MO.Moreover, MO has the same crystal structure as Ml. and form a mutual solid solution.

Here, Ti, Zr, Hf expressed as Mllll-bc
It is believed that there is a reason why nitrides exhibit particularly excellent sinterability. This is true not only for nitrides, but also for carbides represented by MC1bc, carbonitrides represented by M(C9N)1-kX, or the above-mentioned compounds containing two or more metals as M. be.

The inventors are MNlfx + "'1b p" (C1)
It was confirmed that when Ti, Zr, and Hf compounds are shown in the form of 1b, the sinterability is excellent when these compounds with a value of (1±x) of (197 or less) are used as raw materials.

The lower limit of the value of (1±x) for these compounds used in the present invention is approximately 0.40. When it is less than 0.40, these compounds are not single-phase (Ti, Zr.

If a metal phase such as Hf2 coexists, if the amount of this metal phase is large, the hardness of the obtained sintered body will decrease and the wear resistance will deteriorate.

In the sintered body according to the present invention, the heat-resistant compound described above is used as the binder phase of CBN, but in addition to the heat-resistant compound, Al, Eli, or an alloy or compound containing these, as well as Fe, Bli, or C.

Or it contains alloys and compounds containing these in a uniformly mixed state. This binder phase forms a continuous binder phase in the structure of the sintered body, and the heat-resistant compound is
It accounts for 999 volume factors. That is, the main component of the binder phase is a heat-resistant compound phase, and the volume ratio of these metal phases in the sintered body must be equal to or less than the amount of the heat-resistant compound phase.

If it exceeds this range, the heat resistance and wear resistance of the sintered body will decrease, and the performance as a tool will be lost.

In addition to the heat-resistant compounds mentioned above, A! 40s*MgO, A
Compounds such as tN and Si3N may also be contained as subcomponents of the binder phase to the extent that the characteristics of the sintered body of the present invention are not lost, and even if unavoidable impurities mixed in during the process are contained. good. In addition, the sintered body according to the present invention includes elements that are used in the synthesis of OBN and are believed to have solubility in hexagonal boron nitride and OEM at high temperatures and high pressures, such as alkali metals such as Ll, and alkalis such as Mg. earth metals,
It may also contain Pb, Sn, 8b, Al, Cd, Si, etc. as additives.

CEN used as a raw material for the sintered body of the present invention is synthesized under ultra-high pressure using orthogonal boron nitride as a raw material. Therefore, there is a possibility that hexagonal boron nitride remains as an impurity in the OBI+ powder. In addition, even when sintering under ultra-high pressure, the OBN particles do not receive external pressure hydrostatically until the binder penetrates between the individual OEM particles, and the heating during this time produces hexagonal boron nitride. There is also the possibility of reverse metamorphosis. In such a case, if an element having a catalytic effect on the hexagonal boron nitride is added to the mixed powder, it is considered to be effective in preventing this reverse transformation. Based on this idea, the inventors particularly
An experiment was conducted to confirm the effect of Si. A
As an example of a method of adding Si, taking a Group 4a nitride as an example, in this compound MNlfx, (1±x) is 0.
．． 97 or less, add a predetermined amount of ht or Sl, or both, and mix, and then heat to 600°C or higher in vacuum or in an inert atmosphere to remove the relatively excess M and A of MNlh.
M-AA, an intermetallic compound existing on the M-8i phase diagram (for example, when M is T1, T
iA43°T iAt, etc.), and this powder is converted into CB.
This was used as a binder raw material to be mixed with N.

Figure 5 shows the phase diagram of At-Ti, and Figure 6 shows 5i-T1.
The phase diagram of is shown for reference.

For example, in the At-Ti phase diagram shown in Fig. 5, the above TiAt3
．． In addition to TiAt, At mushroom Ti, A4Tit,
It has been shown that intermetallic compounds of AtTi3 can be formed.

In this method, the added Al and Si are uniformly dispersed in the binder, and the effect can be exhibited even with a small amount of addition. Another method is to prepare M-At, M-8 in advance.
An intermetallic compound powder between i may be prepared and added at the time of mixing the raw materials. This also applies when the binder compound is a carbide or carbonitride. Al and El created in this way
A comparison was made between a sintered body to which i was added and a sintered body that did not contain these elements.

When the sintered body is polished and the structure is observed, ht.

It is thought that in the sintered body containing Sl 2 , the OBN particles are less likely to separate from the sintered body on the polished surface, and the bond strength between the OBN particles and the binder phase is stronger.

Also, when comparing the performance as a cutting tool, Al and S
The one containing i was superior in both wear resistance and toughness. It should be noted that this effect appears at 0.1% by weight in the sintered body.
This was a case in which the above At or Sl was included.

The upper limit of the content of At or Sl in the sintered body is up to 20 parts by weight; if it exceeds this, the hardness of the sintered body decreases and the wear resistance deteriorates. In particular, pure At in the binder phase of the sintered body with an excess of At or Sl.

If it exists in the form of Sl, the hardness of the sintered body will be significantly reduced.

Therefore, At or Sl is the other compound-forming metal (T
i, zr, Hf, etc.) or added with other metals (Co.

The amount is limited to the amount that forms a solid solution in (Fe, Ni, etc.) or forms an intermetallic compound with these.

AZ l 51VC shows good performance in the field of low-speed cutting due to the properties of the binder phase when Fe, Ni, and Co are further added. This is compared to a sintered body in which the binder phase is only metal.
This seems to be due to the fact that it has been strengthened.

The sintered body of the present invention has high hardness and toughness, and has excellent heat resistance and wear resistance, and is suitable for use in tools such as wire drawing dies, peeling dies, drill bits, etc. in addition to cutting tools. be.

Examples will be described below.

Reference example 1 C! with an average particle size of 7μ! Using BN powder, make this by volume 6
A mixed powder was prepared in which the remaining part was as shown in Table 1.

Table 1 2% camphor was added to this mixed powder, and it was molded to have an outer diameter of 10 cm and a height of 1.5 cm. This was inserted into a container made of stainless steel. This container was placed in a vacuum furnace at 10"" mHg.
It was degassed by heating to 1100° C. for 20 minutes at a vacuum degree of . This was charged into a girdle type ultra-high pressure device. Pyrophyllite was used as the pressure medium, and a graphite cylinder was used as the heater. Note that there is Na0 between the graphite heater and the sample.
Filled with t. This was sintered under the conditions shown in Table 1. The holding time is U30 minutes. The obtained sintered body has an outer diameter of 1
01111, and the thickness was approximately 11111. This was ground to a flat surface using a diamond grindstone, and further polished using diamond paste.

When the state of the bonding phase was examined by X-ray diffraction, it was found that the bonding phase of the sintered body A was mainly Ti, with small amounts of Ti, A/1.
The sintered body of B is composed of compounds thought to be M, TiAl, and TiAl, and the sintered body of B contains TiTNi in addition to TiN.
Alternatively, a small amount of TiN1 compound was dispersed in the bonded phase. In addition, in C, the bonding phase consisted of Tic and metal N1 phase.

Reference Example 2 T0. with an average particle size of 1μ. o, ys powder and average particle size 3゜μ
The following A4 powders were blended at a weight ratio of 90% and 10%, respectively, and mixed using a V-type blender.

This mixed powder was pressed into a pellet at a pressure of 1 t/cy++", heated to 1000°C in a vacuum furnace, and held for 30 minutes. This was crushed into powder and examined by X-ray diffraction, and it was found that T1N In addition, diffraction peaks that appeared to be T i A t3 + TiAt and 'r:t = Atli were obtained, and metal At was not detected.The TiN powder containing this At compound was 0EI with a volume of 40 and an average particle size of 7μ.
Mix 60 parts of l powder and pack it into a container made of NO. Reference Example 1
In the same manner as above, first raise the pressure to 551 bK, then raise the temperature to 1400°C, hold it for 30 minutes, lower the temperature, and gradually lower the pressure to form a sintered body with an outer diameter of 7 cm and a height of 55 cm. I got it. This sintered body was finished into a die with a hole diameter of 1.0 mm using the same processing method as in the case of making a diamond wire drawing die.

For comparison, dies of the same shape were made using cemented carbide and a diamond sintered body in which diamond powder was bonded with commercially available CO metal.

A W wire drawing test was conducted using this die. As a result of testing under the condition that the W wire rod supplied to the die was preheated to approximately 800°C, the die of the present invention was able to draw a wire of 3-3, but the cemented carbide die was able to draw a wire of 9 out of 200, and sintered diamond The dies were worn out at a wire drawing amount of 1α, and their lifespans were reached.

Reference Example 3 Ti ((!0.4 r NO, 4)0.
8 Add two parts of At powder with an average particle size of 30 μm by weight to the powder, and proceed as in Reference Example 2 to prepare Tt(
c, n) Powder was prepared. This powder and OBN powder having an average particle size of 4 μm were mixed in a volume ratio of 65 mm and 35 mm, respectively, and a sintered body having an outer diameter of 10 cm and a thickness of 1 cm was prepared in the same manner as in Reference Example 1. However, the pressure during sintering was 50 Kb and the temperature was 11
The temperature was 50°C. The sintered body was cut using a diamond cutting blade to create cutting chips, which were brazed to a steel support. For comparison, 0IBN with an average particle size of 3μ was used as a metal CO
A cutting tool of the same shape was made using a commercially available OBN sintered body bonded with the above method, and was used to cut three types of SOr heat-treated steel having the shape shown in FIG. In the figure, A indicates 32 φ, B indicates 12 cod, 0 indicates 196 mm, and the arrow indicates the cutting direction of D.

For comparison, a tool made from a commercially available OBN sintered body in which CBN was bonded with metallic CO was also tested.

The cutting conditions are cutting speed 60 I? I/min depth of cut α1
5■, shipping jl) [112wm/rev. The results of the cutting test show that the sintered body of the present invention can cut the rigid material shown in Fig. 3 at 20
Although it was still possible to cut after actual cutting, the commercially available OEM sintered compact tool used for comparison had a chip on the cutting edge after one cutting.

Example 1 OBN powder with an average particle size of 4μ and TiNO with an average particle size of 1μ
,*g powder, 1181g powder, and carbonyl N1 powder were blended at a volume ratio of 70.15 and 5.10, respectively.

A sintered body was produced in the same manner as in Reference Example 1.

When the sintered body was examined (by X-ray diffraction), it was found to be OBN.

In addition to Tin, TiSi, TiSi2. Ti,
Ni was detected. A cutting chip was machined from the obtained sintered body, and 9 types of heat-treated SROMs (TlRO54) were cut.For comparison, the commercially available OEM sintered body cutting tool used in Reference Example 3 was also tested at the same time. Cutting conditions: depth of cut α2m
, feed) α12 m/rev, and the cutting speed was changed for testing. FIG. 4 shows the time required for the tool flank wear width to reach 0.2 fins versus cutting speed. The sintered body of the present invention has excellent wear resistance, especially in the high speed range.

Example 2 60% by volume of OBN powder with an average particle size of 3μ, the remainder being the second
A binder powder having the composition shown in the table was mixed.

Thereafter, in the same manner as in Reference Example 1, the mixed powder placed in a stainless steel container was sintered under the conditions shown in Table 2.

When the sintered body was polished and its hardness was measured using a micro Vickers hardness meter, E and P were each 2900.280.
It was 0.2700. When the state of the bonded phase was investigated by X-ray diffraction, it was found that in D, Tie, TaN and metallic Ni
, K for TiC, NbO.

For metals Ni and F, in addition to the (xl, Ta) (Or N) phase and the metal N1 phase, a phase that appears to be a compound of Ti, Al, and Ni was observed.

Table 2 Reference Example 4 OBN powder with an average particle size of 4μ and T'i with an average particle size of 1μ
Ce and e 11 powders and Al2O3 powder with an average particle size of α3μ were blended at a volume of 60 and 20.20, respectively. A sintered body was produced in the same manner as in Reference Example 1. The pressure during ultra-high pressure sintering is 45Kb.

The temperature was held at 1200°C for 20 minutes. A cutting tool was made from this sintered body, and the same performance test as in Reference Example 3 was conducted. As a result, it was still possible to cut 20 pieces of the hardened steel workpiece shown in FIG.

Example 3 and Reference Example 5 60% by volume of OBN powder with an average particle size of 3μ, and the remainder was
A binder powder having the composition shown in the table was mixed.

This mixed powder was charged into a molybdenum container.

Thereafter, sintering was carried out in the same manner as in Reference Example 1 by holding the pressure and temperature shown in Table 3 for 10 minutes. In all cases, sufficiently dense sintered bodies were obtained, and the Vickers hardness thereof showed the values shown in Table 3.

Table 5 Example 4 (Zro, r Tao, 5) (Co, e p No, t
) o, j and Al, Si, C.

were mixed in a weight ratio of 80:10:5:5, respectively, and then stamped and treated in vacuum at 1200'C for 15 minutes.

Next, this binder powder was pulverized using a cemented carbide pot and ball. This powder and CBN powder having a particle size of 3 μm were mixed at a ratio of 24 to 6 by volume.

This powder was sintered under ultra-high pressure in the same manner as in Reference Example 1. A chip for cutting was created using the obtained sintered body.

For comparison, a sintered body using co as a binder was also used as a similar chip.

Using the obtained chip, 100X300X10016
The upper surface of 8 RT 4 (J (Re 50)) was milled 7 times.Cutting speed was 120 #1/min, depth of cut Q
, 2111, When cutting was performed at a feed rate of 1 m/blade, the product of the present invention did not break even after 30 minutes of cutting, whereas the comparative product broke after 5 minutes of cutting.

[Brief explanation of the drawing]

Figure 1 explains the characteristics of the sintered body of the present invention.
It shows the change in thermal conductivity of N and various compounds with respect to temperature. FIG. 2 relates to the manufacturing conditions of the sintered body of the present invention, and shows the stable existence region of cubic boron nitride on the pressure and temperature phase diagram. Figure 3 shows the shape of the rigid material used in the cutting performance test to explain the effects of the sintered body of the present invention.The tools used and the contents of the cutting test are shown in Reference Example 3.
The details are described below. FIG. 4 shows the performance of the sintered body of the present invention as a cutting tool, and shows the time required to reach a constant amount of tool wear when the cutting speed is varied. FIG. 5 shows the bonded phase compound of the present invention, A/! , -Ti compound, and FIG. 6 is a Ti-8i phase diagram as well. FIG. 7 is an optical micrograph at a magnification of 1500 times showing the structural characteristics of the sintered body of the present invention. a: cubic boron nitride stability region, b dihexagonal boron nitride stability region, 1: comparative material, 2: sintered body of the present invention. Figure 1 Temperature (°C) Figure 2 Temperature (°C) Figure 3 Cutting time (minutes) Figure 5 Weight %

Claims (6)

[Claims] (1) Contains cubic boron nitride in an amount of 80 to 20% by volume, with the remainder being carbides, nitrides, borides, silicides, or mixtures thereof of transition metals from groups 4a, 5a, and 6a of the periodic table, or mixtures thereof. A solid solution compound, Al, Si, or an alloy or compound containing these, and Fe, Ni, Co, or an alloy or compound containing these are used as a binder phase, and the binder phase forms a continuous binder phase in the sintered body structure, and the A sintered body for a high-hardness tool, characterized in that the volume of a compound of group 4a, 5a, or 6a metal in the binder phase is 50% or more and 99.9% or less. (2) Claim (1) in which the compound or mixture constituting the continuous binder phase is mainly composed of carbides, nitrides, and carbonitrides of Ti, Zr, and Hf in Group 4a of the Periodic Table. sintered body. (3) The sintered body according to claim (1), wherein the compound forming the continuous binder phase is mainly composed of WC. (4) The compound forming the continuous binder phase is mainly composed of carbides, nitrides, and carbonitrides of Ti, Zr, and Hf in Group 4a of the periodic table, and the sintered body contains At or Bi, or The sintered body according to claim (1), which contains both of these in an amount of 0.1% or more and 20% or less by weight. (5) Cubic boron nitride powder and Periodic Table 4a, 5a,
Powders of carbides, nitrides, borides, silicides or mixtures thereof or mutual solid solution compounds of group 6a transition metals, and Al, Bi or alloys and compounds containing these, and F
After mixing powders of e, Bi, Co, or alloys and compounds containing these, it is molded in powder form or by molding, and then sintered using an ultra-high pressure device at a pressure of 20 Kb or higher and a temperature of 700°C or higher. Contains 80 to 20% by volume of cubic boron nitride, which is characterized by its ability to crystallize, and the remainder is carbides, nitrides, borides, silicides, or A mixture of these or a mutual solid solution compound is 50% or more and 99.9% or less by volume in the binder phase, and furthermore, Al, Si or an alloy or compound containing these, and Fe, Ni, Co or an alloy containing these, A method for producing a sintered body for a high-hardness tool, in which the compound and a compound of a group 4a, 5a, or 6a transition metal of the periodic table form a continuous binder phase in the structure of the sintered body. (6) Cubic boron nitride powder and Ti in group 4a of the periodic table
, Zr, Hf carbide, nitride, and carbonitride, respectively, are M
C_1_±_x, MN_1_±_x, M(C,N)_1
When expressed in the form of ＿±＿x (M is Ti, Zr, Hf
powder of these compounds having a value of 1±x of 0.97 or less and 0.40 or more (where x indicates the presence of atomic vacancies or relatively excess atoms), and Al, Si or Alloys and compounds containing these and powders of Fe, Ni, Co, and alloys and compounds containing these are mixed, and this is powdered or after molding, using an ultra-high pressure machine to produce 20Kb.
As mentioned above, cubic boron nitride, which is characterized by being sintered under high pressure and high temperature at a temperature of 700°C or higher, is 80 to 2% by volume.
0%, with the remainder being Ti, Zr, and H from Group 4a of the periodic table.
A compound mainly consisting of carbide, nitride, or carbonitride of f accounts for 50% by volume or more and 99.9% or less in the binder phase, and further A
l, Si or alloys containing these, compounds and Fe,
Consisting of Ni, Co, or alloys or compounds containing these,
A method for producing a sintered body for a high-hardness tool, in which this and carbides, nitrides, and carbonitrides of the Group 4a metals of the periodic table form a continuous binder phase in the structure of the sintered body.