JPH0753262A - Coated diamond sintered compact and its production - Google Patents

Abstract

PURPOSE:To obtain a high performance coated diamond sintered compact having a uniform, dense, tightly sintered and highly controlled microstructure. CONSTITUTION:Core particles made of diamond fine particles having <=10mum average particle diameter in the frequency distribution on volume basis are dispersed in gas at >=70% dispersity beta and collided against or brought into contact with a precursor of a coat forming material to coat the surfaces of the separate particles with the coat forming material and the resulting coated diamond particles or a mixture contg. the particles is sintered under the conditions of <1,850 deg.C temp. and <2,000MPa pressure under which diamond is not thermodynamically stable but metastable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-density diamond sintered body composed of fine particles and a method for producing the same.

[0002]

2. Description of the Related Art Diamond has many excellent properties based on its strong covalent bond, but on the other hand, due to its covalent bond, the self-diffusion coefficient is very small, making it extremely difficult to sinter. Moreover, diamond is thermodynamically stable only under ultrahigh pressure, and at high temperature, it undergoes phase transfer to graphite when the pressure is insufficient. Therefore, a dense and high-hardness diamond sintered body containing diamond is thermodynamically stable because the diamond prevents the phase transition to the graphite phase and sinters the diamond sintered body densely. It was manufactured under ultra high pressure and high temperature exceeding 2000 MPa. For example, according to a report by T. NOMA et al. (J. Master. Scie. 19 (1984) 2319-2322), diamond is 6000 MPa (60 kb), 130
Sintered at 0 ° C or higher. These sintering conditions are extremely severe as an extreme state, and could not occur unless an ultra-high pressure device such as a girdle type or belt type was used. Therefore, diamond sintered compacts are difficult to mass-produce and the manufacturing cost is high due to the restriction of using ultra-high pressure equipment such as girdle type or belt type that generates ultra-high pressure exceeding 2000 MPa. The product could not be manufactured.

However, Hall
According to the experiment under ultrahigh pressure, even if the diamond is not thermodynamically stable, if it is thermodynamically metastable, the phase transition takes an extremely long time, so that the diamond is practically stable. As a practical upper limit, it is reported by showing the line in Fig. 1 (HT Hall, Science, 169).
(1970) 868-869). Therefore, according to this, even under the conditions of low pressure and high temperature, which are not stable with respect to the thermodynamic equilibrium line of FIG. 1, at a temperature not exceeding the line of FIG. 1, for example, when the pressure is up to about 35 kb, Up to 1400K (about 1100 ° C), diamond is practically stable. Based on this fact, if it is possible to produce a diamond-containing diamond sintered body under these conditions, 2000
An ultrahigh pressure device capable of generating a relatively gentle ultrahigh pressure of less than MPa, for example, a piston-cylinder (PC) type ultrahigh pressure device, or an ultrahigh pressure HIP device capable of pressurizing up to 1000 MPa as a known technique, or It becomes possible to manufacture by using a hot isostatic pressing (HIP: Hot Isostatic Press) device or a hot press (HP: Hot Press) device excluding an ultra-high pressure HIP device. Therefore, unlike the case of the ultra high pressure device such as the girdle type or the belt type which generates an ultra high pressure exceeding 2000 MPa, mass production is easy,
In addition, a large-sized sintered body can be manufactured.

In recent years, such an ultrahigh pressure device capable of acting a relatively gentle ultrahigh pressure of less than 2000 MPa, for example, a piston-cylinder (PC) type ultrahigh pressure device, or 100
Ultra-high pressure HIP equipment capable of pressurizing up to 0 MPa, or hot isostatic pressing (HIP: Hot Isost) excluding this ultra-high pressure HIP equipment
atic Press) device or hot press (HP: Hot Pr)
There is a strong demand for mass production of dense and high-performance diamond sintered compacts containing a relatively large amount of diamond fine particles and for manufacturing large-sized products using an ess) device. However, it is not easy to effectively densify a diamond sintered body containing a relatively large amount of diamond under such a limited pressure. That is, when the diamond sintered body is sintered, the binder added in the form of the raw material powder of the binder deforms or moves to fill the gaps between the diamond particles, and voids or pores surrounded by the binder and the diamond particles. It becomes possible only when pressure acts effectively on the elimination and disappearance of. For that purpose, the binder and / or the raw material powder of the binder that reacts with the diamond to generate the binder must be in contact with and around the diamond powder particles. Especially when the pressure is 20
When the pressure is less than 00 MPa, diamond is not thermodynamically stable, but it is almost impossible to expect direct bonding under the conditions of metastable sintering at pressure and temperature. The diamond particle portions in which the raw material powder of 1) does not exist become unsintered. in this case,
The performance of the diamond sintered body is significantly reduced. As a result, the advantages such as the above-mentioned large-scale production being easy and the production of a large-sized sintered body are meaningless. Therefore, the binder and / or the diamond reacts with the binder around the diamond powder particles. There must be a substance that becomes.

That is, the binder and / or the substance which reacts with the diamond and becomes the binder is present in contact with around the diamond consisting of fine particles, so that 2000 MPa
Ultra-high pressure device capable of acting relatively loose ultra-high pressure of less than,
For example, a piston / cylinder (PC) type ultra high pressure device,
Alternatively, an ultra-high pressure HIP device capable of pressurizing up to 1000 MPa, or hot isostatic press (HI
P: Hot Isostatic Press) equipment or hot press (HP: Hot Press) equipment is used to mass-produce dense and high-performance diamond sintered compacts containing relatively large amounts of fine particles and manufacturing large-sized products. Will be possible for the first time. For that purpose, coated diamond particles obtained by coating fine powder diamond particles with a coating forming substance are indispensable, and a coating method for producing the coated diamond particles is an important technique.

There are various methods such as a vapor phase method and a wet plating method for coating the diamond powder particles with a coating forming substance. Among them, the vapor phase method is, in principle, (1) controlled atmosphere. Easy (2) Basically, there is no limitation on the selection of substances as a binder and / or a sintering aid, and simple substance substances such as active metals, nitrides, carbides, borides, oxides, etc. Can be coated with various kinds of substances, (3)
Other coatings such as a target substance can be coated with high purity as a binder and / or a sintering aid, and (4) the amount of the binder substance and / or the sintering aid substance can be arbitrarily controlled. There are major advantages that cannot be achieved by law. However, the substance that serves as a binder and / or the substance that serves as a sintering aid by the vapor phase method,
When the diamond particles are fine particles or when the diamond particles are mainly fine particles, it is impossible to coat the individual diamond powder particles for the following reasons.

That is, when the diamond powder particles to be coated are fine particles, the particles of the core particle powder to be coated or the particles of the core particle powder mainly composed of fine particles are powder particles. Because of the strong adhesive force of, the aggregation property is high, and most single particles form aggregates. Since this agglomerate cannot be broken and broken unless a special action exceeding its cohesive force is applied, even if the agglomerate is coated as it is, a binder and / or a sintering aid to the surface of each particle is obtained. The coating with the agent is not possible, and eventually the coated agglomerate in which the surface of the agglomerate is coated with the binder and / or the sintering aid is produced. As a result, the individual diamond particles forming the agglomerate have a problem that the particles located on the agglomerate surface have uneven coating although the particle surface has a large amount of coating, and the particles located inside the agglomerate have no problem. there were.

In an attempt to solve the above problems, when the diamond core particle powder particles to be coated are fine particles, the particles of the core particle powder to be coated or the core particle powder mainly composed of fine particles are individually There has already been an attempt to disperse and coat the particles in order to coat the particles. For example,
Device disclosed in Japanese Patent Laid-Open No. 58-31076
According to the method, particles of the core particle powder are put in a container installed in a PVD apparatus, the container is vibrated by an electromagnetic method, and the core particles in the container are rolled and coated by the PVD method. To do. Further, according to the device disclosed in Japanese Patent Laid-Open No. 61-30663, particles of core particle powder are put in a container installed in a PVD device, and the container is vibrated by a mechanical method. It is said that the core particles in the container are covered by the PVD method while rolling. However, in the apparatus or method for coating while rolling the particles of the core particle powder by the vibration of these containers, in practice, particles of the core particle powder or particles of the core particle powder mainly composed of fine particles are used. Since it is not possible to add an action exceeding the cohesive force required to break up the agglomerates of certain diamond powder particles, this agglomerate cannot be broken and rather the granulating action works, more than before before being introduced into the container, It only formed more or larger aggregates. JP-A-3-15386
The apparatus and method disclosed in Japanese Patent No. 4 discloses that particles are placed in a rotating container having a barrier and / or unevenness on the inner surface, and the surface of the core particles is coated by vapor deposition while rotating the rotating container. Although intended, in such an apparatus or method, in order to break up the agglomerates of the diamond powder particles, which are the particles of the core particle powder of fine particles or the particles of the core particle powder mainly composed of fine particles. Since no action exceeding the required cohesive force can be applied, not only this aggregate cannot be broken, but also more or larger aggregates are formed.

Japanese Unexamined Patent Publication (Kokai) No. 58-141375 discloses a deposit material produced by a chemical reaction of a reaction gas by suspending a powder placed in a reaction gas atmosphere by the flow of the reaction gas and the action of gravity. Discloses a device for coating the surface of powder. Further, Japanese Patent Application Laid-Open No. 2-43377 discloses a method of performing coating by performing thermochemical reaction treatment while fluidizing fine particles under reduced pressure.
In an apparatus or method utilizing a fluidized bed by these air streams, it is practical to fluidize each diamond powder particle which is a particle of fine particle core particle powder or a particle of core particle powder mainly composed of fine particles. It was impossible, and the aggregate of the diamond powder particles could not be broken. JP-A-54-15
Japanese Patent No. 3789 discloses an apparatus for dropping a powder material in a vacuum container in which vapor of metal is generated to coat the metal. Further, Japanese Patent Laid-Open No. 60-47004 discloses a method of introducing a monomer gas and powder particles into a high frequency plasma region in a vacuum chamber and forming a coating film of an organic substance by plasma polymerization. As in these devices or methods, the introduction of the particles did not destroy the particles of the fine particle core particle powder or the aggregates of the diamond powder particles, which are particles of the core particle powder mainly composed of fine particles.

Japanese Unexamined Patent Publication No. 64-80437 discloses a low
A method is disclosed in which agglomerates of core particle powders are broken down and fluidized by high-frequency synthetic sound waves for coating. However, with this method of vibrating the fluidized bed, the agglomerates of diamond powder particles, which are particles of fine particle core particle powder or particles of core particle powder mainly composed of fine particles, could not be broken. JP 62-
In the 250172 publication, as a pretreatment, the powder subjected to the jet mill treatment is retained in a reduced pressure heat treatment chamber, subjected to the heat treatment therein, and then introduced into the sputtering chamber by a powder feeder by a natural drop to set a target. An apparatus and method are disclosed in which a vertically-arranged cylindrical sputtering chamber is naturally dropped and coated. Further, in Japanese Patent Laid-Open No. 153068/1990, powder subjected to jet mill treatment as a pretreatment is retained in a reduced pressure heat treatment chamber, where after heat treatment is performed,
An apparatus and a method are disclosed in which a powder feeder introduces powder in a rotary container containing a sputtering source in a sputtering chamber and sputters the container in a rotated state. In these devices, the powder is temporarily dispersed by the jet mill treatment only at that time, but the structure is such that this powder stays in the heating step before coating. Even if it is temporarily dispersed in the primary particle state, it reaggregates due to the retention of this powder in this heating step, and eventually remains agglomerated when it is introduced into the coating step.

As described above, all of the above-mentioned problems are problems as an apparatus or method for coating the particles of the fine particle core particle powder or the diamond powder particles which are the particles of the core particle powder mainly consisting of fine particles. No solution has been made. Therefore, coated diamond powder particles in which each of the diamond powder particles is uniformly coated with a substance serving as a binder and / or a substance serving as a sintering aid as a coating forming substance by a base phase coating method. Could not be produced. For this reason, it has been impossible to mass-produce a dense and high-performance diamond sintered body containing the above-mentioned fine particles and containing a relatively large amount of diamond, or to manufacture a large-sized shaped product.

[0012]

Therefore, in practice, the diamond powder particles to be coated, for example 10
The particles of the fine particle core particle powder or the particles of the core particle powder mainly consisting of fine particles, which are particles having an average particle diameter of μm or less, are used as a binder in a single particle unit and / or as a sintering aid. The diamond from the coated diamond powder particles coated with the substance as a coating-forming substance is not thermodynamically stable, but a relatively large number of diamond particles composed of fine particles obtained by sintering at metastable pressure and temperature. There is a strong demand for the realization of a high-performance diamond sintered body and a method for producing the same. INDUSTRIAL APPLICABILITY The present invention relates to a particle of a fine particle core particle powder or a diamond powder particle which is a core particle powder particle mainly composed of fine particles, in a single particle unit, a substance serving as a binder and / or a substance serving as a sintering aid. Homogeneous, dense and strong, which comprises sintering coated diamond particles or a mixture containing the same coated as a coating forming material at a pressure of less than 2000 MPa and a temperature of not more than 1850 ° C. An object of the present invention is to provide a diamond sintered body containing a relatively large amount of diamond particles composed of sintered and high-performance fine particles having a highly controlled microstructure and a method for producing the same.

[0013]

[Means for Solving the Problems] Although the pressure is less than 2000 MPa and the diamond is not thermodynamically stable, it is difficult to directly bond the diamond to each other under the metastable pressure and temperature sintering conditions. Therefore, the portion of the obtained sintered body in which no binder is present is unsintered. In the present invention, a binder that does not react with diamond and / or a substance that reacts with diamond to form a binder must be present around the diamond powder particles. It has been found that it is most suitable to apply coated diamond particles coated with. At the same time, the present invention provides that, at the time of sintering a high-performance binder and diamond, at least the coating forming material coated on the diamond particles is in the same state, and / or the reaction formation between the coating forming material and diamond is generated. As a binding material, these are deformed or moved to fill the gaps between the diamond particles, the binding material and the diamond are bonded,
By applying pressure that is effective only for eliminating and eliminating voids and pores surrounded by the binder and diamond, it becomes possible to densify the diamond sintered body, and to manufacture a coated diamond sintered body with highly controlled microstructure. Found that is possible. To this end, the uniformity of the coating on the diamond powder particles, which are particles of fine particle core particle powder having a volume-based frequency distribution and an average particle diameter of 10 μm or less, or particles of core particle powder mainly consisting of fine particles, It has been found that coating quality such as uniformity is the key to the success of the production of coated diamond sinter. That is, the inventors of the present invention have proposed that the particles of the fine particle core particle powder or the diamond powder particles, which are the core particle powder mainly composed of fine particles, serve as a binder in single particle units and /
Alternatively, in order to coat a substance serving as a sintering aid as a coating-forming substance, particles of core particle powder having a volume-based frequency distribution and an average particle size of 10 μm or less are mainly present in the air in a single particle state. The coating of the particles of the highly dispersed core particle powder / the particles of the core particle powder in the gas mixture must be started in the coating start region of the coating space in a highly dispersed state where the dispersity β is 70% or more. Found out.

More specifically, (I) the core particle powder in which the particles of the diamond powder are dispersed in the state of a particle / gas mixture of the highly dispersed core particle powder in which the particles mainly exist in the air in a single particle state. Particles tend to re-aggregate due to brown agglomeration, turbulent agglomeration, sonic agglomeration, etc. over time, even if they are not retained. For example, it is difficult to break the state of re-aggregation and re-disperse it.
Particles of core particle powder having a volume-based frequency distribution and an average particle diameter of 10 μm or less are mainly present in the air in a single particle state. Particles of highly dispersed core particle powder It is necessary to guide the particles to the coating start region of the coating space in a highly dispersed state where the dispersity β is 70% or more, and in order to do so, (II) disrupt the agglomerates of the particles of the core particle powder. In addition, it has a particularly high dispersion performance of one or more, which disperses the particles of the highly dispersed core particle powder existing mainly in the air in the form of a single particle / the particles of the core particle powder in the gas mixture in a highly dispersed state. It has been found that a distributed processing means group having is necessary.

And sintering the coated diamond powder particles thus obtained at a pressure below 2000 MPa at which diamond is not thermodynamically stable but metastable and at a temperature not exceeding 1850 ° C. Thus, a high-performance diamond sintered body having a uniform, dense, and strongly sintered microstructure with highly controlled microstructure was obtained. That is, according to the present invention, a PC type ultrahigh pressure device capable of generating a relatively gentle ultrahigh pressure of less than 2000 MPa, an ultrahigh pressure HIP device capable of pressurizing up to 1000 MPa, or a device other than the above-mentioned ultrahigh pressure HIP device is used. A sintered body obtained by uniformly and densely and strongly sintering diamond particles coated with HIP apparatus or HP apparatus in each sintering environment without causing phase transition of diamond into a graphite phase. Can be done. Furthermore, it has been found that the coated diamond particles have a sintering behavior similar to that of the particles of the coating material itself, whereby the coated diamond sintered body can be strengthened and has a minor axis of 500 μm or less, It has also been found out that it is possible to add and sinter a fibrous substance composed of one or more kinds of metal or compound having a shape in which the ratio of the major axis to the minor axis is 2 or more, and the present invention has been completed.

That is, according to the present invention, particles of a core particle powder composed of fine diamond particles, or particles of a core particle powder mainly composed of the same fine particles, the surface of which is coated with a coating-forming substance, are used. In producing a diamond sintered body by sintering, the diamond particles coated with the coating-forming substance, the core-particle powder is introduced into the coating space, and the coating-forming substance precursor and / or Alternatively, a coating-forming substance precursor in a gas phase is brought into contact with and / or colliding with particles of the core particle powder to coat the surfaces of the particles of the core particle powder with the coating-forming substance, ) The final treatment means of the fine particle high dispersion treatment means group is
(A) Dispersing means for dispersing the particles of the core particle powder in the air, and (b) Low dispersion in a mixture of the particles of the core particle powder and the gas in which the particles of the core particle powder are dispersed in the air. Highly dispersed core particle powder particles that separate the core particle powder part and select the particle / gas mixture of highly dispersed core particle powder in which the particles of the core particle powder mainly exist in the air in a single particle state. A gas mixture selecting means and particles of the high-dispersion core particle powder, a low-dispersion core particle powder portion selectively separated by the gas-mixture selecting means, and a final dispersing means among the dispersing means in the fine particle high dispersion treatment means group And / or particles of highly dispersed core particle powder provided with feedback means for conveying to the processing means before the final dispersion means
An average particle diameter of 10 μm in a volume-based frequency distribution is obtained by a group of means for highly dispersing fine particles selected from a gas mixture selecting means.
The following dispersion step of dispersing the particles of the fine particle core particle powder or the particles of the core particle powder mainly composed of fine particles in the air to form a particle / gas mixture of the highly dispersed core particle powder, (B) this dispersion Coating in which the particles of the core particle powder dispersed in the step are contacted and / or collided with the coating material precursor in the coating start region of the coating space in a dispersed state having a dispersity β of 70% or more to start coating. 2000MP of the coated diamond particles or a mixture containing the same is used.
A method for producing a coated diamond sintered body characterized in that a diamond having a pressure lower than a and a temperature not higher than 1850 ° C. is not thermodynamically stable, but is sintered under a metastable pressure and temperature sintering conditions. It is provided.

Further, the present invention provides a method for producing a diamond sintered body as described above, wherein diamond particles coated with a coating forming substance form aggregates in contact with each other through the coating forming substance of the coated diamond particles. Crushing and / or crushing the coated agglomerates of coated diamond particles, and / or the step of crushing and agglomerating the agglomerated agglomerates of coated diamond particles, and / or the coated diamond particle agglomerates and the coated diamond in primary particle units. Prepared by further performing a selective separation step of selectively separating the particles and the coated diamond particles, or a mixture containing the particles, from which the diamond is not thermodynamically stable but metastable less than 2000 MPa. And a method for producing the above-mentioned sintered body, in which sintering is performed at a pressure of 1850 ° C. and a temperature not exceeding 1850 ° C.

Further, the present invention provides a method for producing a diamond sintered body as described above, wherein core particles composed of diamond fine particles whose surface is to be coated with a coating-forming substance, or particles composed mainly of the same. The particles of the powder are particles of a core particle powder or particles of a core particle powder mainly composed of fine particles, which are one or more particles coated with a coating substance derived from the immersion method by a dipping method using a molten salt bath, The coated diamond particles obtained by coating the same with a coating-forming substance, or a mixture containing the particles are treated at a pressure below 2000 MPa where the diamond is not thermodynamically stable but metastable,
And a method for producing the above-mentioned sintered body, which comprises sintering at a temperature not exceeding 1850 ° C.

Furthermore, the present invention is a method for producing a diamond sintered body as described above, wherein the diamond particles coated with the coating forming substance are core particle powders having a volume-based frequency distribution and an average particle diameter of 10 μm or less, By the final treatment of the fine particle high-dispersion treatment means group, it is dispersed in the air to form a particle / gas mixture of highly dispersed core particle powder, which has a dispersion performance of making the degree of dispersion β of the particles of the core particle powder 70% or more. A fine particle high dispersion treatment means group is provided with a dispersion step, and the particle / gas mixture of the highly dispersed core particle powder dispersed by the fine particle high dispersion treatment means group is directly discharged to the coating step or between the dispersion step and the coating step. In addition, from the discharge part for discharging the particle / gas mixture of the high-dispersion core particle powder dispersed by the fine particle high-dispersion treatment means group, an intermediate member consisting of a hollow member and a member for forming a hollow, which is inevitable for transportation. And / or conveyed through one or more members selected from members and pipes, and / or
Alternatively, an air dispersion maintaining means for maintaining the air dispersion state of the particles in the particle / gas mixture of the highly dispersed core particle powder dispersed in the air with the dispersion performance, and dispersed in the air with the dispersion performance. An air dispersion promoting means for increasing the air dispersion state of particles in a highly dispersed core particle powder / gas mixture, and a low dispersion core particle powder portion in a mixture of particles and gas of the core particle powder. The particles / gas mixture of the highly dispersed core particle powder for separating and selecting the particle / gas mixture of the highly dispersed core particle powder in which the particles of the core particle powder mainly exist in the air in a single particle state Prepared by transporting through one or more, and the coated diamond particles, or a mixture containing the particles, of less than 2000 MPa, where the diamond is not thermodynamically stable but metastable. At pressure and temperature not exceeding 1850 ° C Also it relates to the preparation of the sintered body sintered.

Furthermore, the present invention is a method for producing a diamond sintered body as described above, wherein the diamond particles coated with the coating forming substance are core particle powders having a volume-based frequency distribution and an average particle diameter of 10 μm or less, It has a dispersibility in which it is dispersed in the air by the final treatment of the fine particle high-dispersion processing means group to form a particle / gas mixture of highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder is 70% or more. The coated diamond particles are prepared by performing a part or more of the dispersion step and a part or more of the coating step by the fine particle high-dispersion treatment means group while sharing a part or more of the space, and the coated diamond particles. , Or a mixture containing the same particles, wherein diamond is not thermodynamically stable but metastable at a pressure of less than 2000 MPa and a temperature of not more than 1850 ° C. Also related to the law.

Furthermore, the present invention is a method for producing a diamond sintered body as described above, wherein the diamond particles coated with the coating forming substance are core particle powders having a volume-based frequency distribution and an average particle diameter of 10 μm or less, By the final treatment of the fine particle high dispersion treatment means group, it is dispersed in the air to form a particle / gas mixture of the highly dispersed core particle powder, and the dispersion degree β of the particles of the core particle powder is 70% or more. Of the core particle powder in the gas mixture of the highly dispersed core particle powder in the space area including the surface through which all the particles pass, or the coating start area of the coating space is located on the volume basis. A core particle powder having an average particle diameter of 10 μm or less in a frequency distribution is dispersed in the air by a final treatment of a fine particle high dispersion treatment means group to be a particle / gas mixture of the highly dispersed core particle powder. Dispersion degree of powder particles Was prepared by positioning the coating start region of the coating space in a space region including a surface through which all the particles to be recovered by the recovery unit of the recovery means out of the space region of 70% or more. And a sintered body comprising the coated diamond particles, or a mixture containing the same, at a pressure below 2000 MPa at which diamond is not thermodynamically stable but metastable, and at a temperature not exceeding 1850 ° C. Also relates to the manufacturing method of.

Furthermore, in the present invention, in the above-mentioned method for producing a diamond sintered body, the diamond particles coated with the coating-forming substance have a particle size distribution with an average particle diameter of D
_{Let M} be the volume-based frequency distribution ([D _M / 5,5
D _M ], ≧ 90%) was prepared by coating a core particle powder with a coating-forming substance, and the diamond was thermodynamically treated with the coated diamond particles or a mixture containing the same. 2000 which is not stable but metastable
It also relates to a method for producing the above-mentioned sintered body, which is sintered at a pressure lower than MPa and a temperature not higher than 1850 ° C. The present invention also relates to a coated diamond sintered body manufactured by the above-mentioned manufacturing method.

Thus, according to the present invention, the particles of the core particle powder consisting of the diamond fine particles or the particles of the core particle powder mainly consisting of the same fine particles, the surface of which is coated with the coating forming substance, Pressure of less than 2000MPa and 1
When producing a sintered body of diamond particles by sintering at a temperature not exceeding 850 ° C., a coating forming substance produced as a diamond particle whose surface is coated with a coating forming substance through a vapor phase by a vapor phase method. A high-dispersion core particle powder comprising a precursor and / or a coating-form substance precursor in a gas phase state and fine particles having an average particle size of 10 μm or less dispersed in the air by the final processing means of the fine particle high-dispersion processing means group. The particles and the gas mixture are merged in the coating start region of the coating space in a dispersion state in which the degree of dispersion of the particles of the highly dispersed core particle powder and the particles of the core particle powder in the gas mixture is β ≧ 70%, By using the one in which the surface of the diamond particles is coated with a coating material by contacting and / or colliding with each other, it is possible to obtain a diamond particle surface, which has not been obtained hitherto, with a non-sintered portion, which is uniform and compact. It was possible to obtain a dense and strongly sintered high-performance diamond sintered body having a highly controlled microstructure using a pressure device capable of generating a relatively gentle ultrahigh pressure of less than 2000 MPa. . Then, in the preparation of the above-mentioned coated core particles, the coating material precursor is in a gas phase state consisting of atoms, molecules, ions, clusters, atomic clusters, molecular clusters, cluster ions, etc.,
Alternatively, it is one that has just been formed through the gas phase, and by starting contact and / or collision with highly dispersed diamond particles, the coating forming substance is strongly bonded to the surface of each core particle in the primary particle state, As a result, coated diamond particles can be produced in which the surface of the core particles is coated with the coating forming substance in single particle units.

Before describing the present invention in detail below, the terms used in the present specification will be defined first, and if necessary, the specific contents of the terms will be explained, followed by coating with a coating forming material. The technical means for preparing the diamond particles will be described below.

Coated Diamond Particles Coated diamond particles are the following coated diamond particles. For example, specifically, the coating-forming substance is coated on the diamond particles as core particles in one or more forms of ultrafine particles, islands, continuous substances, uniform films, protrusions, and the like. Refers to particles.

Diamond Raw Material Powder Particles According to the present invention, the diamond powder particles, which are the particles of the fine particle core particle powder or the particles of the core particle powder mainly consisting of fine particles, are coated with the coating forming substance on the surface thereof. The raw material particles of diamond particles for the coated diamond particles include natural and / or artificial diamond powder particles. In the case of a natural product, an ultra-high purity product can be selected, which is preferable. In the case of synthetic products, it is preferable to remove substances used as catalysts during synthesis as much as possible. As a particularly preferable example of a synthetic product, for example, a physical vapor deposition method (PVD
Method) or a chemical vapor deposition method (CVD method), ultrahigh-purity diamond synthesized through the gas phase and containing no catalytic substance can be selected. When synthesizing into a thin film, crush and use it while paying attention to the inclusion of impurities. When synthesized in a granular or powder form, it can be used as it is. As a high-purity example other than this, a single crystal can be selected. Alternatively, it is possible to select one in which impurities are positively removed. As the diamond raw material powder for producing the high-performance coated diamond sintered body, diamond particles having an average particle diameter of 10 μm or less are used. Specifically, diamond has an average particle size D _M of 10 μ.
The volume-based frequency distribution is ([D _M / 5,5D _M ], ≧
Since 90% of diamond powder particles are generally distributed, this can be applied. Depending on the application, diamond powder particles having a relatively narrow average particle size D _M of 10 μm or less and a volume-based frequency distribution ([D _M / 3,3D _M ], ≧ 90%), or classification, etc. The particle size of the diamond particles is controlled by the average particle size D _M having a narrow distribution and is 10 μm or less, and the volume-based frequency distribution is ([D _M / 2,3D _M / 2], ≧
90%) diamond powder particles can be selected.

Vapor Phase Coating Method The vapor phase coating method is a method in which the raw material of the coating forming material is coated at least once in a vapor phase state composed of one or more of molecular flow, ion flow, plasma, gas, vapor and aerosol. ,
Alternatively, it refers to a method of coating with a raw material of a coating forming substance in a gas phase.

Core Particles Core particles are particles to be coated. This is also referred to as matrix particles, seed particles or coated particles. The core particles consist of diamond.

Core particle powder The core particle powder is a powder composed of core particles. The particles of the core particle powder refer to particles constituting the core particle powder. The particles of the fine particle core particle powder or the particles of the core particle powder mainly composed of fine particles used for the coating used in the present invention have an average particle size of 10 μm or less in volume-based frequency distribution. Preferably, when the average particle diameter is D _M , D _M is 10 μm or less, and the particle size distribution is a volume-based frequency distribution ([D _M / 5,5D _M ], ≧ 9.
0%). In such a powder having a relatively narrow distribution, the dispersion property or agglomeration property of the powder is characterized by the average particle size, and the fine particle high dispersion treatment means group is operated under the conditions suitable for the value of D _M. Can be dispersed. For core particles having an average particle diameter of 10 μm or less, the particle size distribution of the particles is broad or has a plurality of peaks separated from each other. A coating treatment is applied to each of the classified powders. As a result, under the above conditions for each classified powder, the coating is started in the coating start region of the coating space with the dispersity β of 70% or more, and the core particles Coating is possible.

Coating-forming substance The coating-forming substance is a substance that forms a coating on an object to be coated. For example, specifically, ultrafine particles, islands,
It refers to a substance that forms the particle coating of the core particle powder in the form of one or more of continuous material, uniform film, and protrusion. In particular, when the form of the coating-forming substance is in the form of ultrafine particles, the particle size of the ultrafine particles is, for example, in the range of 0.005 μm to 0.5 μm. This coating forming substance forms a coating as it is, or the coating forming substance reacts with the diamond of the core particles and / or forms a solid solution with the diamond particles and / or two or more kinds of Inorganic compounds, alloys intended to form coatings by reacting and / or alloying and / or solid-solving coating-forming substances
And / or a sintering aid which produces one or more intermetallic compounds and the like and promotes the sintering of the coated diamond particles.
Alternatively, it is selected from a simple substance and / or a compound serving as a binder and / or a simple substance and / or a compound serving as a surface modifier of the diamond particles.

As the coating forming substance for directly coating the diamond particles, a coating forming substance which does not promote the phase transition of diamond into the graphite phase is selected. The coating forming substance can be selected as a surface modifier for controlling the grain boundaries of the diamond particles. If necessary, for example, the chemical bond between the diamond particles and the sintering aid and / or the binder may be enhanced, or the individual diamond particles may be separated from any substance, so that the diamond phase of the diamond may be increased. The phase transition can be suppressed, or the reaction between diamond and any substance can be suppressed. As a result, the range of selection of the coating material as the sintering aid and / or the binder is greatly expanded, which is preferable.

These coating-forming substances are available in the periodic table 1a,
2a, 3a, 4a, 5a, 6a, 7a, 1b, 2b, 3
b, 4b, 5b, 6b, 7b, group 8 metals, semiconductors, semimetals, rare earth metals, nonmetals and their oxides, nitrides, carbides, oxynitrides, oxycarbides, carbonitrides, oxycarbonitrides , One or more of borides, silicides, eg Al, B,
Si, Fe, Ni, Co, Ti, Nb, V, Zr, H
f, Ta, W, Re, Cr, Cu, Mo, Y, La, T
iAl, Ti ₃ Al, TiAl ₃ , TiNi, NiAl,
Ni ₃ Al, SiC, TiC, ZrC, B ₄ C, WC, W
₂ C, HfC, VC, TaC, Ta ₂ C, NbC, Mo ₂
C, Cr ₃ C ₂ , Si ₃ N ₄ , TiN, ZrN, Si ₂ N
₂ O, AlN, HfN, VxN (x = 1 to 3), Nb
N, TaN, Ta ₂ N, TiB, TiB ₂ , ZrB ₂ , V
B, V ₃ B ₂ , VB ₂ , NbB, NbB ₂ , TaB, TaB
₂ , MoB, MoB ₂ , MoB ₄ , Mo ₂ B, WB, W
₂ B, W ₂ B ₅ , LaB ₆ , B ₁₃ P ₂ , MoSi ₂ , BP, A
l ₂ O ₃ , ZrO ₂ , MgAl ₂ O ₄ (spinel), Al ₂ S
It can be a substance containing one or more of iO ₅ (mullite). The amount of the coating forming substance that coats the surface of the coated diamond particles by coating is not particularly limited, but preferably an arbitrary amount that can densify the coated diamond sintered body is selected.

Definition of charging into the coating space The charging into the coating space means, for example, introducing the core particle powder into the coating space by falling such as free fall. When charging with carrier gas, the core particle powder is introduced by being carried in the flow direction of the particle / gas mixture of the core particle powder, or by riding the gas in the flow direction or by changing the riding direction in the gas. It means being introduced. Alternatively, it also means that the gas is introduced under the action of the carrier gas. For example, it also refers to introduction by a wave phenomenon of carrier gas, specifically, a non-linear wave. Alternatively, it also means introducing into the coating space by a sound wave in a gas, an ultrasonic wave, a magnetic field, an electron beam, or the like. It also means introduction by an external field such as an electric field, a magnetic field, or an electron beam. Specifically, it also means that the powder particles are charged or magnetized by an electric field, a magnetic field, an electron beam or the like and introduced into the coating space by an attractive force or a repulsive force. It also includes the introduction and introduction of gas by back pressure or pressure reduction.

Coating Space The coating space is a precursor of a coating-forming substance which is produced from a raw material of a coating-forming substance through a gas phase and / or a coating-forming substance precursor in a gas phase and particles of core particle powder contact and / or Or, it means the space where it collides. Alternatively, it refers to a space region in which the surface of the particles of the core particle powder is coated with the coating forming substance.

Coating Chamber The coating chamber is a chamber having a coating space or more. More specifically, the coating chamber is a partition including a coating space,
Or it is a room that is partitioned (generally closed, semi-closed),
This is a room that contains a part or more of the coated space.

In the air, the air refers to the inside of a vacuum or a gas phase space. here,
In the present invention, the gas phase state means a state such as molecular flow, ion flow, plasma, gas and vapor. The vacuum is technically a reduced pressure state. Strictly speaking, gas, molecule, atom, ion, etc. are contained under any reduced pressure.

Coating Forming Substance Precursor A coating forming substance precursor is a precursor of a coating forming substance. More specifically, the raw material of the coating-forming substance in the vapor phase is formed as it is, or is formed and / or synthesized from the raw material of the coating-forming substance through the vapor phase to form a coating on the core particles which are particles to be coated. It refers to the substance until just before. The coating substance precursor is not limited in its state as long as it is formed and / or synthesized from the raw material of the coating substance via the gas phase. When the raw material of the coating forming substance is in the gas phase, this raw material can also be a coating forming substance precursor. The coating forming material precursor itself may be in the gas phase. When the coating-forming substance precursor is a reactive substance, it may be before the reaction, during the reaction, or after the reaction. Specific examples of the coating material precursor include ions, atoms, molecules, clusters, atomic clusters, molecular clusters, cluster ions, ultrafine particles, gas, vapor and aerosols.

Raw Material of Coating Forming Material The raw material of the coating forming material means a raw material which becomes a material which forms a coating through a gas phase. Specific examples of the form of the raw material of the coating forming substance include lumpy solids, powder particles, gas and liquid.

Dispersity β Dispersity β is an index for evaluating the dispersion performance of a powder disperser, proposed by Masuda, Goto et al. )), The ratio of the weight of particles in the apparent primary particle state to the weight of all particles is defined. Here, the particles in the apparent primary particle state are the overlap of the mass-based frequency distribution f _m2 of the powder particles in an arbitrary dispersed state and the mass-based frequency distribution f _m1 of the completely dispersed powder particles. The ratio of the part that is shown is represented by β in the following equation.

[0040]

[Equation 1] In the above equation, the unit of particle diameter (μm) is not specified. In the above formula, the dispersity is evaluated based on the particle size distribution expressed on a mass basis, but the dispersity should be evaluated based on the particle size distribution expressed on a volume basis. However, when the powder particle densities are the same, the particle size distribution expressed by mass and the particle size distribution expressed by volume are the same. Therefore, the particle size distribution based on mass, which is practically easy to measure, is measured,
It is used as a volume-based particle size distribution. Therefore, the original dispersion degree β is represented by the following equation and the area of the shaded portion in FIG.

[0041]

[Equation 2] In the above equation, the unit of particle diameter (μm) is not specified. And the distribution and average particle size of the core particle powder are
Unless otherwise specified, the volume standard is basically used.

Volume-Based Frequency Distribution The volume-based frequency distribution refers to the distribution of particle diameters expressed by the volume ratio contained in a certain particle diameter.

[0043] ([D _1, D _2], ≧ 90%) Definition of ([D _1, D _2], ≧ 90%) and the distribution, D _1, the particle diameter D _2, where D ₁ <D ₂ , A distribution in which 90% or more by volume of particles of D ₁ or more and D ₂ or less is contained, and a powder composed of particles having a shaded portion ratio of 90% or more as shown in FIG. Represent

Volume-based frequency distribution ([D _M / 5,5D _M ],
≧ 90%) The particle size distribution is a volume-based frequency distribution ([D _M / 5,5
D _M], and is ≧ 90%) distribution, when the average particle diameter on a volume basis of D _M, 1/5 times the particle size or less on the D _M, volume 5 times under particle size or less particles of D _M Represents a distribution containing 90% or more. For example, when the average particle size D _M is 5 μm and the volume-based frequency distribution is ([D _M / 5,5D _M ], ≧ 90%), it means that the volume-based average particle size is 5 μm and the particles are 1 μm or more and 25 μm or less. The distribution is such that 90% or more by volume of particles are included. Here, the volume-based average particle diameter D _M is

[Equation 3] Alternatively, technically, a certain particle size interval is set to D _i ± ΔD _i / 2 (Δ
D _i is the volume of the particles that are within the width of the segment) and V _i, is expressed by _{D M = Σ (v i D} i) / Σv i.

Coating start region The region where coating is started for the first time after the final treatment of the fine particle high dispersion treatment means group is called the coating start region. Therefore, even before the final treatment of the fine particle high-dispersion treatment means group, the area where the coating is first started is not the coating start area here.

Dispersion degree β in the coating start region In the present invention, the average particle diameter is 10 μm in the volume standard frequency distribution.
The following core particle powder is dispersed in the air by the final treatment of the fine particle high dispersion treatment means group to form a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion β of the particles of the core particle powder is 70.
A coating chamber for locating the coating start region of the coating space is provided in the region of which the ratio is at least%. As far as the degree of dispersion is in the coating start region of the coating space, the particles of the core particle powder having an average particle diameter of 10 μm or less in the volume-based frequency distribution or the particles of the core particle powder mainly composed of fine particles are substantially At least a part of the surface of the particles of all the core particle powder that can be dispersed in the air in units of 1 in the air and provided for coating, and pass through the coating start region of the coating space, and the precursor for forming the coating material. Since they come into contact with and / or collide with, it is always possible to attach the coating forming substance to each particle.

Preferably, in the coating start region of the coating space, core particle powder having a volume-based frequency distribution and an average particle diameter of 10 μm or less is dispersed in the air by the final dispersion treatment of the fine particle high dispersion treatment means group. As a particle / gas mixture of highly dispersed core particle powder, the degree of dispersion β of the core particle powder is 80%.
That is all. As far as the degree of dispersion is in the coating start region of the coating space, the particles of the core particle powder have a volume-based frequency distribution and the average particle diameter is 10 μm or less. There is virtually no closed portion between core particles with respect to body particles, and it is possible to contact and / or collide with the coating material precursor everywhere on the surface of each particle. The particle surface can be coated almost uniformly. More preferably, in the coating start region of the coating space, the average particle diameter is 1 in the volume-based frequency distribution.
The core particle powder having a particle diameter of 0 μm or less is dispersed in the air by the final dispersion treatment of the fine particle high dispersion treatment means group to obtain a particle / gas mixture of the highly dispersed core particle powder, and the degree of dispersion of the particles of the core particle powder. β is 90% or more. If the dispersity of the coating start region of this coating space is such that the particles of the core particle powder have a volume-based frequency distribution and the average particle diameter is 10 μm or less, the particles of the core particle powder or the core particle powder mainly composed of the fine particles are used. Even the particles of the body are virtually non-aggregated and can be coated substantially uniformly on the entire surface of each individual particle. In particular, since the treatment efficiency may be low, when high quality coating is desired, the dispersity is
95% or more is more preferable. In this case, it becomes possible by treating a small amount of particles of the core particle powder to reduce the number concentration of particles of the completely dispersed core particle powder in the air. As a result, the entire surface of each particle can be uniformly coated.

Fine Particle High Dispersion Processing Means A fine particle high dispersion processing means group includes (A) at least one dispersion means, and (B) as a final processing means, (a) particles of core particle powder Or (b) a core particle powder in which a low-dispersion core particle powder portion is separated in a mixture of particles of a core particle powder in which particles of the core particle powder are dispersed in air and gas. Highly dispersed core particles in which the body particles mainly exist in the air in a single particle state. Highly dispersed core particle powder particle / gas mixture selection means for selecting a particle / gas mixture of the highly dispersed core particle powder and this highly dispersed core particle powder. The low-dispersion core particle powder portion separated by the particle / gas mixture selecting means of the body is conveyed to the final dispersion means and / or the processing means before the final dispersion means of the dispersion means in the high-fine particle dispersion processing means group. Of highly dispersed core particle powder with feedback means Particle / gas mixture selecting means. Preferably, a core particle powder having a volume-based frequency distribution and an average particle size of 10 μm or less is dispersed in the air by a final treatment of a group of means for highly dispersing fine particles to form a particle / gas mixture of the highly dispersed core particle powder, The core particle powder has a dispersibility in which the degree of dispersion β of the particles is 70% or more.
Various degrees of dispersion in the coating start region, for example β ≧ 7
By providing a group of means for high-dispersion fine particles having a dispersion performance equal to or higher than those of 0%, 80%, and 90%,
In the coating start region, high-quality coating can be applied according to each dispersity.

Final Treatment Means When the final treatment means of the group of fine particle high dispersion treatment means is a dispersion means, this dispersion treatment means is called the final treatment means of the group of fine particle high dispersion treatment means. Further, the final processing means of the fine particle high-dispersion processing means group was in a low dispersion state at the time of the particle / gas mixture selective processing step of the high-dispersion core particle powder to the final dispersion means of the high-fine particle dispersion processing means. The particle / gas mixture selection means for the highly dispersed core particle powder provided with a feedback means for conveying the selected and separated portion, or the particle / gas mixture for the highly dispersed core particle powder to the treatment means before the final dispersion means. In the case of the particle / gas mixture selecting means of the highly dispersed core particle powder provided with the feedback means for conveying the selectively separated portion due to the low dispersion state in the mixture selection treatment step, this highly dispersed core particle powder The means for selecting a particle / gas mixture is referred to as the final treatment means of the fine particle high dispersion treatment means group. still,
It is provided before the particle / gas mixture selecting means of the high-dispersion core particle powder having the feedback means which is the final processing means of this fine particle high-dispersion processing means group (for example, the high-dispersion core particle powder having this feedback means). Between the particle / gas mixture selection means and the final dispersion means, or before the final dispersion means) The particle / gas mixture selection means for the highly dispersed core particle powder is the same as that of the fine particle high dispersion treatment means group regardless of the presence or absence of the feedback means. It is a component.

Dispersing Means The means used to disperse the fine particles is called a dispersing means.
This dispersing means can be used as a dispersing means if it has a dispersing effect even if only a little or slightly. For example, a rotary feeder for air transportation and an injection feeder (edited by Japan Society of Powder Engineering: “Powder Engineering Handbook”, Nikkan Kogyo Shimbun (1986) P568, P571), which are generally used as a supply means, have a dispersing effect, and thus are dispersed. When used as a target means, it is a dispersion means. For the purpose of dispersion, the dispersion maintenance / promotion means described later (β
When it is used), it becomes a dispersion means. The dispersing means may be a single device or equipment or a combined device or equipment, and these are collectively referred to as a fine particle high dispersion treatment means group. This fine particle high-dispersion processing means group is for accelerating the particles of the core particle powder and / or dispersing the particles of the core particle powder by an air flow, and colliding the particles of the core particle powder with stationary obstacles and / or obstacles made of rotating bodies. One or more of the selected dispersions, such as a fluidized bed of particles of a core particle powder and / or a pulsating flow and / or a rotating drum and / or mechanical crushing consisting of vibration and / or scraping. It is equipped with a mechanism.

Specifically, the fine particle high dispersion treatment means group is
Ejector type disperser, Venturi type disperser, Capillary tube, stirrer, Disperser using obstacles in air flow, Disperser using jet spraying, Spiral tube, Disperser using rotating blades, Spinning pin Disperser (cage mill), fluidized bed type disperser, pulsating disperser, rotating drum disperser, vibration disperser, vibrating sieve, scraper scraping scraper , SAEI, Gone
ll type disperser, Nakajo type disperser, Roller type disperser, Orifice type disperser, BM type disperser, Timbrell type disperser, Wright
It is equipped with a dispersing means consisting of one or more selected types such as a type disperser (edited by Japan Society of Powder Engineering: “Powder Engineering Handbook”, Nikkan Kogyo Shimbun (1986) P430).

Further, a disperser utilizing a stirring blade described in JP-A-56-1336, a disperser utilizing a high-speed air stream and a dispersion nozzle described in JP-A-58-163454, and JP-A-59-199027. Disperser utilizing the dispersing action by the rotating blade and the dispersing action by plasma ions described in No.
A disperser utilizing the dispersing action of plasma ions described in JP-A-59-207319, and JP-A-59-2166.
No. 16, a disperser utilizing the dispersing action of an ejector and plasma ions, No. 59-225728, a disperser utilizing the dispersing action of an ejector and an ion flow, and No. 59-183845. Disperser utilizing the dispersing action of plasma ions of JP-A-63-1664
No. 21, a disperser utilizing a dispersing action by a dispersion blade and a pressure gas, a disperser using a line-shaped or ring-shaped slit type jet outlet described in JP-A-62-176527,
A disperser using a mesh blade described in JP-A No. 63-221829, a disperser using a dispersing action by a high-speed air stream from an injection nozzle described in JP-A No. 63-1629, No. Shokai 63-9218. And the ejector type disperser described in Japanese Utility Model Publication No. 62-156854, and the disperser using the micropores and orifices described in Japanese Utility Model Publication No. 63-6034. Those described in can also be used. As a dispersing means suitable for a group of means for highly dispersing fine particles, Japanese Patent Application No. 63-311358 and Japanese Patent Application No. 1-7107 can be used.
No. 1, Japanese Patent Application No. 2-218537 and the like.

Highly-dispersed core particle powder particle / gas mixture selection means Highly dispersed core particle powder particle / gas mixture selection means means a low-dispersion core particle powder from a core-particle powder particle / gas mixture. A means for separating a particle / gas mixture and selecting a particle / gas mixture of highly dispersed core particle powder mainly containing particles in a single particle state. Aggregated particles, which are aggregates of primary particles, have an apparent particle diameter larger than the particle diameter of primary particles, and therefore can be separated by, for example, a dry classification means. Examples of the particle / gas mixture selecting means for the highly dispersed core particle powder include a classification means using gravity, a classification means using inertial force, a classification means using centrifugal force, a classification means using static electricity, and a flow method. Examples include dry classification means selected from one or more of classification means using layers. Examples of means for selecting a particle / gas mixture of highly dispersed core particle powder include a gravity classifier,
Inertia classifier, centrifugal classifier, cyclone, air separator, micron separator, microplex, multiplex, zigzag classifier, accu cut, conical separator, turbo classifier, super separator,
Dispersion separator, elbow jet, fluidized bed classifier, virtual impactor, O-Sepa, sieve, vibrating screen, shifter (Powder Engineering Society:
"Powder Engineering Handbook", Nikkan Kogyo Shimbun, P514 (198)
6)) and the like.

Particle / gas mixture of core particle powder A particle / gas mixture of core particle powder means (a) a homogeneous flow in which particles of the core particle powder are uniformly suspended in air (a uniform floating flow). ), (B) Inhomogeneous flow (non-homogeneous floating flow) in which particles of the core particle powder show a non-uniform distribution in a certain area in the air, (c) accompanied by a sliding layer of particles of the core particle powder Flow (sliding flow), or
(d) A flow with a stationary layer of particles of core particle powder.

Particles / gas mixture of low-dispersion core particle powder The particles / gas mixture of low-dispersion core particle powder means particles of the core particle powder mainly in the particles / gas mixture of the core particle powder. A particle-gas mixture of core particle powder that exists in the air in a state other than a single particle state.

Particle / gas mixture of highly dispersed core particle powder A particle / gas mixture of highly dispersed core particle powder is a core particle powder in which the particles of the core particle powder mainly exist in the air in a single particle state. A particle / gas mixture of the body. Highly dispersed core particles Powder particles
The gas mixture, even with a very high dispersion, actually contains agglomerated particles. The particle / gas mixture of low-dispersion core particle powder is
Actually, it contains unaggregated single particles, and is selectively separated into a particle / gas mixture of low-dispersion core particle powder and a particle / gas mixture of high-dispersion core particle powder. The particle / gas mixture of the low-dispersion core particle powder becomes a particle / gas mixture of the high-dispersion core particle powder by selectively separating and / or re-dispersing the agglomerated particles.

Collecting Means The means for taking out the coated particles coated in the coating space is called collecting means. The part of the recovery means that performs the recovery process is called the recovery part. The coated particles that have passed through the coating start region of the coating space and are coated are directly taken out of the air and collected, or taken out of the air and temporarily stored and then collected, or are collected together with the gas. As the collecting unit of the collecting unit, a collecting unit of a collecting unit using a partition wall (obstacle), a collecting unit of a collecting unit using gravity, a collecting unit of a collecting unit using inertial force, a collecting unit using centrifugal force Collection part, collection part of collection means using attractive force due to electrification, collection part of collection means using thermophoretic force, collection part of collection means using Brownian diffusion, suction force by back pressure or decompression of gas, etc. It is possible to use the recovery unit of the recovery means used. Preferable examples of the collecting unit of the collecting means include a gravity dust collector, an inertial dust collector, a centrifugal dust collector, a filter dust collector, an electric dust collector, a washing dust collector, a particle packing layer, a cyclone, a bag filter, a ceramics filter, a scrubber, and the like.

Next, a group of means for high-dispersion fine particle treatment adopted when preparing coated diamond particles used in the present invention will be described with reference to the accompanying drawings.

FIG. 3 (a) is a block diagram showing an example of the basic structure of the fine particle high dispersion treatment means group when preparing coated diamond particles. It is composed of the final dispersion means A for dispersing the particles of the core particle powder and the constituent element d of the dispersion processing means group before the final dispersion means. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder. As the constituent element d, any treatment means such as a dispersion means, a supply means, a particle / gas mixture selection means of highly dispersed core particle powder can be used alone or in combination. The component d does not necessarily have to be provided.
The fine particle high-dispersion treatment means group preferably has a dispersity of β after the treatment by the dispersion means A, which is the final treatment means, with respect to the core particle powder having a volume-based frequency distribution and an average particle diameter of 10 μm or less. In this configuration, 70% or more can be realized.

FIG. 3B is a block diagram showing a second example of the basic constitution of the fine particle high dispersion treatment means group when preparing coated diamond particles. The final dispersion means A for dispersing the particles of the core particle powder, and the particles of the core particle powder to the final dispersion means A are particles of the highly dispersed core particle powder in the air mainly in the form of a single particle. Other than the gas mixture, the particles / gas mixture selecting means B of the final high-dispersion core particle powder having the feedback means C for feeding back the particles / gas mixture η of the low-dispersion core particle powder, the dispersion before the final dispersion means It is composed of the constituent element d of the processing means group and the constituent element e of the high particle dispersion processing means group between the final dispersion means and the final selection means. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder. As the constituent element d, any processing means such as a dispersing means, a supplying means, a selecting means can be used alone or in combination. As the component e, a processing means other than the dispersion means, for example, an arbitrary processing means such as a supply means and a selection means can be used alone or in combination. The components d and e are
It does not have to be provided. The fine particle high dispersion treatment means group preferably has a dispersity degree β with respect to the core particle powder having the above-mentioned distribution after the treatment by the selection means B which is the final treatment means.
With this configuration, 70% or more can be realized.

FIG. 3C is a block diagram showing a third example of the basic constitution of the fine particle high dispersion treatment means group when preparing coated diamond particles. Highly dispersed core particles in which particles of the core particle powder are mainly present in the air in a single particle state to the final dispersion means A for dispersing the particles of the core particle powder and the processing means prior to the final dispersion means A. Powder / particle mixture of low-dispersion core particles other than powder / particle / gas mixture of high-dispersion core particles having feedback means C for feeding back gas mixture η, and final dispersion means It is composed of the component d of the previous fine particle high dispersion treatment means group and the component e of the fine particle high dispersion treatment means group between the final dispersion means and the final selection means. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder. As the constituent element d, any processing means such as a dispersing means, a supplying means, a selecting means can be used alone or in combination. As the constituent element d, any processing means other than the dispersion means, for example, an arbitrary processing means such as a supply means and a selection means can be used alone or in combination. The components d and e do not necessarily have to be provided.
The fine particle high-dispersion treatment means group is preferably configured such that after the treatment by the selection means B, which is the final treatment means, the degree of dispersity [beta] of 70% or more can be realized with respect to the core particle powder having the above distribution. .

Because of the above-mentioned structure, the powder supply source such as the supply tank and the core particle generating means may be included in the structure of the fine particle high dispersion processing means group. For example, in the case of FIG. 3C, it goes without saying that the configuration in which the feedback destination of the feedback unit C is the supply tank may be the configuration of the high dispersion processing unit group. Needless to say, a crushing step of crushing and / or crushing the particles of the core particle powder may be added before the dispersing step of the fine particle high dispersion treatment means group.

A concrete representative example of the basic constitution of the above-mentioned group of means for highly dispersing fine particles will be explained in more detail based on a more detailed block diagram. Configuration 1 FIG. 4 (a) is a block diagram for explaining the first configuration of the fine particle high dispersion treatment means group when preparing coated diamond particles, and corresponds to FIG. 3 (a). This example comprises a supply tank 100 for supplying the core particle powder to be coated, and a final dispersion means A for dispersing the core particle powder to be coated. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

Structure 2 FIG. 4 (b) is a block diagram for explaining the second structure of the fine particle high-dispersion processing means group for preparing coated diamond particles, which corresponds to FIG. 3 (a). Is. This example comprises a supply tank 100 for supplying the core particle powder to be coated, a dispersing means a for dispersing the core particle powder to be coated, and a final dispersing means A for dispersing the core particle powder to be coated. There is. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

Structure 3 FIG. 4 (c) is a block diagram for explaining the third structure of the fine particle high dispersion treatment means group when preparing coated diamond particles, and corresponds to FIG. 3 (a). Is. In this example, among the supply tank 100 for supplying the core particle powder to be coated, the dispersing means a for dispersing the core particle powder to be coated, and the particle / gas mixture of the core particle powder dispersed by the dispersing means a Mainly in the form of a single particle in the air, which is a high-dispersion core particle powder particle / gas mixture, other than low-dispersion core particle powder particle /
A feedback means C for feeding back the gas mixture η to the dispersing means a, a particle / gas mixture selecting means b for mainly introducing the particle / gas mixture of the highly dispersed core particle powder into the final dispersing means A. The final dispersion means A for dispersing the core particle powder to be coated. ε
Is a particle / gas mixture of the highly dispersed core particle powder, which is mainly present in the air in the form of a single particle among the particles of the core particle powder.

Structure 4 FIG. 4 (d) is a block diagram for explaining the fourth structure of the fine particle high dispersion treatment means group when preparing coated diamond particles and corresponds to FIG. 3 (b). Is. In this example, a supply tank 100 for supplying the core particle powder to be coated, a final dispersion means A for dispersing the core particle powder to be coated, and a particle / gas mixture of the core particle powder dispersed by the final dispersion means A. Feedback means for feeding back the particles / gas mixture η of the low-dispersion core particle powder other than the above, mainly the particles / gas mixture of the high-dispersion core particle powder existing in the air in the form of a single particle to the dispersion means A C, the final high-dispersion core particle powder particle / gas mixture selecting means B for releasing the high-dispersion core particle powder particle / gas mixture. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

Structure 5 FIG. 4 (e) is a block diagram for explaining the fifth structure of the fine particle high-dispersion processing means group for preparing coated diamond particles, which corresponds to FIG. 3 (b). Is. In this example, a supply tank 100 for supplying the core particle powder to be coated, a dispersing means a for dispersing the core particle powder to be coated, a final dispersing means A for dispersing the core particle powder to be coated, and a final dispersing means. Of the low-dispersion core particle powder other than the high-dispersion core particle powder particle / gas mixture mainly existing in the air in the form of a single particle among the particle / gas mixture particles of the core particle powder dispersed in A. It comprises a feedback means C for feeding back the particle / gas mixture η to the dispersing means A, and a final particle / gas mixture selecting means B for releasing the particle / gas mixture of the highly dispersed core particle powder. There is. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

Structure 6 FIG. 4 (f) is a block diagram for explaining the sixth structure of the fine particle high dispersion treatment means group when preparing coated diamond particles, and corresponds to FIG. 3 (b). Is. In this example, a low-dispersion core particle powder / gas mixture is mainly removed from the supply tank 100 for supplying the core particle powder to be coated, and a particle / gas mixture of the core particle powder is removed, and mainly high dispersion is performed. A highly dispersed core particle powder particle / gas mixture selecting means b for introducing the particle / gas mixture of the core particle powder into the dispersing means A, a final dispersing means A for dispersing the particles of the core particle powder selected and separated,
Low-dispersion core particles other than particles / gas mixture of highly dispersed core particle powder mainly existing in the air in a single particle state from particles / gas mixture of core particle powder dispersed by final dispersion means A. From the feedback means C for feeding back the powder particle / gas mixture η to the dispersion means A, the final high dispersion core particle powder particle / gas mixture selection means B for releasing the high dispersion core particle powder particle / gas mixture. It is configured. ε is
Among the particles of the core particle powder, it is a particle / gas mixture of highly dispersed core particle powder that exists in the air mainly in the form of a single particle.

Structure 7 FIG. 4 (g) is a block diagram for explaining the seventh structure of the fine particle high dispersion treatment means group for preparing coated diamond particles and corresponds to FIG. 3 (c). Is. In this example, a supply tank 100 for supplying the core particle powder to be coated, a dispersing means a for dispersing the core particle powder to be coated, a final dispersing means A for dispersing the core particle powder to be coated, and a final dispersing means. Of the low-dispersion core particle powder other than the high-dispersion core particle powder particle / gas mixture mainly existing in the air in the form of a single particle among the particle / gas mixture particles of the core particle powder dispersed in A. It comprises a feedback means C for feeding back the particle / gas mixture η to the dispersing means a, and a final particle / gas mixture selecting means B of the highly dispersed core particle powder for discharging the highly dispersed core particle powder particle / gas mixture. There is. [epsilon] is a particle / gas mixture of highly dispersed core particle powder, which exists in the air mainly in a single particle state among particles of the core particle powder.

In order to maintain the high-dispersion state of the fine particles thus achieved, an air dispersion maintaining means may be added between the fine particle high-dispersion processing means group and the coating chamber. The term "in-air dispersion maintaining means" as used herein means means for preventing re-aggregation of particles of the core particle powder dispersed and carried in air to maintain the degree of dispersion β. Further, in order to promote the highly dispersed state of the core particles thus achieved, an air dispersion promoting means can be added between the fine particle high dispersion treatment means group and the coating chamber. The air dispersion promoting means here promotes redispersion of mainly reaggregated particles among particles of the core particle powder dispersed and carried in the air, and slows down the deterioration of the dispersed state, or once decreases It means a means for promoting re-dispersion so as to recover the dispersed state to the original highly dispersed state.

Suitable examples of the air dispersion maintaining means or the air dispersion promoting means include a pipe vibrating device, a pipe heating device, a plasma generator, a charging device and the like. The pipe vibration device uses the vibration of the pipe where the oscillator is installed,
This is a means for suppressing re-aggregation and maintaining a high dispersion state or a means for accelerating the dispersion of re-aggregated particles by giving vibrations, which cannot be called a disperser, to particles dispersed in air. The pipe heating device expands the carrier gas by applying heat from the outside of the carrier gas by the heated pipe, accelerates the flow velocity so that it can not be called a disperser, suppresses reaggregation, and disperses the reaggregated particles. It is a means to promote. The plasma generator generates plasma in the air carrying the core particle powder in a dispersed manner, and collision between the plasma ions and the core particles suppresses re-aggregation and maintains a high dispersion state or re-aggregated. It is a means of promoting dispersion of particles. The charging device uses a method such as corona discharge, electron beam, or radiation to generate unipolar ions in the air carrying the core particle powder, and the particles are unipolar by passing through the unipolar ion atmosphere. Charged to
It is a means for suppressing reaggregation by the repulsive force of static electricity and maintaining a high dispersion state, or a means for promoting the dispersion of reaggregated particles.

The highly dispersed core particle powder of the fine particles thus formed is sent to the coating chamber for coating the surface of the particles with the coating forming substance. A coating space including a coating start area is provided in the coating chamber. It is desirable that the high-fine particle dispersion chamber treatment means group and the coating chamber are directly connected, but they may be connected by using a hollow member and / or a pipe which is inevitable for transportation. Also in this case, it is essential to realize β ≧ 70% in the coating start region. When the fine particle high dispersion treatment means group and the coating chamber are separately placed and connected to each other, the core particle powder may be introduced into the coating chamber in the dispersed state. For that purpose, the air dispersion maintaining means and / or the air dispersion promoting means and / or the core particle powder which is an apparatus for maintaining the dispersed state of the core particle powder during this period. High-dispersion core particle powder particles that separate the low-dispersion core particle powder part from the particle-gas mixture and select the high-dispersion core particle powder particle / gas mixture that mainly contains particles in a single particle state -Gas mixture selection means can also be provided.

When preparing coated diamond particles, the group of means for high-dispersion fine particles comprises (1) a coating chamber,
Alternatively, (2) the coating space, or (3) the coating starting region may share a part or more of the space. For example, the dispersion space and the coating chamber in the fine particle high dispersion means group, or the dispersion space in the fine particle high dispersion means group and the coating space having the coating start region, or the dispersion space and the coating space in the fine particle high dispersion means group. The start region can also be spatially shared. Here, the coating start region is a coating material precursor and / or a gas phase coating material precursor that is generated in a highly dispersed state of core particle powder that is transported in a dispersion state of β ≧ 70% through a gas phase. Body contact and /
Or, it refers to the area where collision occurs and coating starts, and the next FIG.
The aspects represented by (e) are considered. That is, FIG.
In (a) to (e), the coating start region is a region indicated by 2.

In FIG. 5A, β ≧ 70% with respect to the powder
The coating start region 2 of the coating space for starting coating in the dispersed state is provided so as to cover the fine particle high dispersion treatment means group or the discharge part 1 of the fine particle high dispersion treatment means group. In FIG. 5B, the above β ≧ 7 through which all the particles 4 of the core particle powder discharged from the discharge unit 1 of the fine particle high dispersion treatment means group or the fine particle high dispersion treatment means group pass.
A coating start region 2 of the coating space in which coating is started in a dispersed state of 0% is provided. With the above structure, the coating of all the particles of the core particle powder is started in a dispersed state of β ≧ 70%. Figure 5
In (c), among the particles 4 of the core particle powder discharged from the discharge unit 1 of the fine particle high-dispersion treatment means group or the fine particle high-dispersion treatment means group, the particles that enter the recovery unit 5 must pass through β ≧ 7.
A coating start region 2 of the coating space in which coating is started in a dispersed state of 0% is provided.

In FIG. 5 (d), the above β
A coating start region 2 of the coating space in which coating is started in a dispersed state of 70% is provided. In FIG. 5 (e), the recovery unit 5 is placed at a position where only the particles of the highly dispersed core particle powder and the particles of the gas mixture can reach.
To provide. Therefore, the area 6 here is a selecting means utilizing gravity. Particles of highly dispersed core particles powder that enters the collection section
The coating start region 2 of the coating space in which the particles of the gas mixture always pass and in which the coating is started in the dispersion state of β ≧ 70% is provided as shown by the hatched portion in the figure. Only core particles that have begun to be coated in a dispersed state of β ≧ 70% can be collected, and core particles that have not passed through the coating start region and coated particles that have passed through the coating start region do not mix.

From the above, the apparatus for producing coated diamond particles is composed of a fine particle high dispersion treatment means group and a coating chamber, or a fine particle high dispersion treatment means group, a coating chamber and a recovery means. However, the components of these devices can be combined in various ways,
A configuration example of these devices will be described below with reference to the drawings.

Apparatus Configuration 1 FIG. 6 (a) is a block diagram illustrating the configuration of a first apparatus for producing coated diamond particles. This apparatus of this example is a coating apparatus manufacturing apparatus main body 2-A, a coating chamber 2-B1, a coating space 2-B2, a coating start area 2-B.
3, fine particle high dispersion treatment means group 2-C1, collection means 2-D
It consists of Fine particle high dispersion treatment means group 2-C1
Is directly connected to the coating chamber 2-B1.

Device Configuration 2 FIG. 6 (b) is a block diagram illustrating the configuration of a second device for producing coated diamond particles. This apparatus of this example is a coating apparatus manufacturing apparatus main body 2-A, a coating chamber 2-B1, a coating space 2-B2, a coating start area 2-B.
3, a fine particle high dispersion treatment means group 2-C1, an unavoidable hollow member 2-C2, and a recovery means 2-D. The fine particle high dispersion treatment means group 2-C1 is connected to the coating chamber 2-B1 via an unavoidable hollow member 2-C2.

Device Configuration 3 FIG. 6 (c) is a block diagram illustrating the configuration of a third device for producing coated diamond particles. This apparatus of this example is a coating apparatus manufacturing apparatus main body 2-A, a coating chamber 2-B1, a coating space 2-B2, a coating start area 2-B.
3, a fine particle high dispersion treatment means group 2-C1, an air dispersion maintaining means 2-C3, and a collecting means 2-D. The fine particle high dispersion treatment means group 2-C1 is connected to the coating chamber 2-B1 through the air dispersion maintaining means 2-C3.

Apparatus Configuration 4 FIG. 6 (d) is a block diagram illustrating the configuration of a fourth apparatus for producing coated diamond particles. This apparatus of this example is a coating apparatus manufacturing apparatus main body 2-A, a coating chamber 2-B1, a coating space 2-B2, a coating start area 2-B.
3, fine particle high dispersion treatment means group 2-C1, collection means 2-D
It consists of Fine particle high dispersion treatment means group 2-C1
Shares a space with the coating chamber 2-B1.

Apparatus Configuration 5 FIG. 6 (e) is a block diagram illustrating the configuration of a fifth apparatus for producing coated diamond particles. This apparatus of this example is a coating apparatus manufacturing apparatus main body 2-A, a coating chamber 2-B1, a coating space 2-B2, a coating start area 2-B.
3, fine particle high dispersion treatment means group 2-C1, collection means 2-D
It consists of Fine particle high dispersion treatment means group 2-C1
Is provided in the coating chamber 2-B1.

Device Configuration 6 FIG. 6 (f) is a block diagram illustrating the configuration of a sixth device for producing coated diamond particles. This apparatus of this example is a coating apparatus manufacturing apparatus main body 2-A, a coating chamber 2-B1, a coating space 2-B2, a coating start area 2-B.
3, fine particle high dispersion treatment means group 2-C1, collection means 2-D
It consists of Fine particle high dispersion treatment means group 2-C1
The coating chamber 2-B1 is provided in the dispersion space.

Apparatus Configuration 7 FIG. 6 (g) is a block diagram illustrating the configuration of a seventh apparatus for producing coated diamond particles. This apparatus of this example is a coating apparatus manufacturing apparatus main body 2-A, a coating chamber 2-B1, a coating space 2-B2, a coating start area 2-B.
3, fine particle high dispersion treatment means group 2-C1, recovery means 2-
D, recoating and supplying means 2-E. Highly-dispersed treatment means group 2-
It is conveyed to C1 by the re-coating supply means 2-E, and the coating process can be repeated. The coated diamond particles are produced by any of the apparatuses having such a constitution.

The coated particles obtained by coating the core particle powder which is the diamond particles with the coating forming substance as described above can be coated with the coating forming substance again, or this recoating can be repeated. In this case, the coated particles are sent to the recoating supply means. Here, the recoating supply means is
Means for transporting the coated particles after coating to the group of means for high-dispersion fine particle treatment for recoating. Specifically, it is a means provided with (a) a collecting means for collecting the coated particles, and (b) a covering particle conveying means for conveying the covering particles from the collecting means to the fine particle high dispersion treatment means group. Alternatively, (a) a collecting means for collecting the coated particles, (b) a covering particle conveying means for conveying the covering particles from the collecting means to the fine particle high dispersion treatment means group, (c)
And means for classifying coated particles after coating to classify coated particles. When the coating amount is large, the particle size distribution of the core particle powder before coating and the particle size distribution of the coated particles after coating change. Therefore, it is effective to adjust the particle size distribution of the coated particles after coating by the coated particle classification means and perform the recoating treatment. This recoating process can be repeated as necessary, and the coating amount of the coating forming substance can be set to a desired value. Further, this coating treatment can be repeated by changing the type of the coating forming substance, and in this way, it is also possible to multiply coat a substance of a plurality of components as a coating forming substance.

The apparatus for producing coated particles used in the present invention is not limited as long as the coating forming material is an apparatus for producing coated particles in which the particle surface of the core particle powder is coated by the vapor phase method of passing through the vapor phase. . For example, as a chemical vapor deposition (CVD) device,
Thermal CVD equipment, plasma CVD equipment, CVD using electromagnetic waves (visible light CVD, laser CVD, ultraviolet CV
D, infrared CVD, far infrared CVD) device, MOCVD
As the apparatus or the like or the physical vapor deposition (PVD) apparatus, a vacuum vapor deposition apparatus, an ion sputtering apparatus, an ion plating apparatus or the like can be applied. More specifically, for example, a particle whose surface is coated with ultrafine particles disclosed in JP-A-3-75302 and a coated particle manufacturing apparatus described in the manufacturing method thereof are suitable.

As described above, in the present invention, a precursor of a coating forming substance which is produced by introducing particles of fine particle core particle powder, which is a diamond particle, or core particle powder mainly consisting of fine particles into the coating space and passing through the gas phase. And / or a coating-form diamond precursor is produced in which the surface of the particles of the core particle powder is coated with the coating-form material by contacting and / or colliding with a particle of the core-form powder of the coating-form material precursor However, the basic steps of the present invention are summarized as follows.

I (A) The particles of the fine particle core particle powder having an average particle diameter of 10 μm or less in the volume-based frequency distribution or the particles of the core particle powder mainly consisting of fine particles are aerated by the high-dispersion fine particle treatment means group. A dispersion step of dispersing into a particle / gas mixture of the highly dispersed core particle powder, (B) particles of the highly dispersed core particle powder / particles of the gas mixture of the core particle powder dispersed in this dispersion step,
A coating method including a coating step of starting coating by contacting and / or colliding with a precursor of a coating forming substance in a coating starting region of a coating space in a dispersed state having a dispersity β of 70% or more.

II (A) Fine particles having an average particle diameter of 10 μm or less in a volume-based frequency distribution, or particles of a core particle powder mainly composed of fine particles were dispersed by means of a fine particle high dispersion treatment means group. High-dispersion core particle powder-Highly dispersed core particle powder-
Dispersion / mixing step of forming a gas mixture, (B) particles of highly dispersed core particle powder / particles of core particle powder of a gas mixture dispersed in this dispersion step, in a dispersed state having a dispersity β of 70% or more,
A coating method comprising a coating step of contacting and / or colliding with a precursor of a coating forming substance in a coating starting region of a coating space to start coating.

III (A) Fine particles having a volume-based frequency distribution and an average particle diameter of 10 μm or less Fine particles of core particle powder or particles of core particle powder mainly composed of fine particles are dispersed by a fine particle high dispersion treatment means group. Particles of highly dispersed core particle powder / particles of gas mixture core particle Fine particles that achieve a degree of dispersion β of 70% or more.
A dispersion mixture step of forming a gas mixture, (B) a conveying step of directly conveying the particles of the highly dispersed core particle powder and the core particle powder of the gas mixture dispersed in this dispersion step to the coating step,
(C) The degree of dispersion β of the particles of the highly-dispersed core particle powder and the particles of the gas-core mixture of the gas mixture carried in this carrying step is 70
A coating method comprising a coating step of contacting and / or colliding with the coating forming material precursor in the coating starting region of the coating space to start coating in a dispersed state of not less than%.

IV (A) Fine particles having a volume-based frequency distribution and an average particle diameter of 10 μm or less Fine particles of core particle powder or particles of core particle powder mainly composed of fine particles were dispersed by means of a fine particle high dispersion treatment means group. High-dispersion core particle powder-Highly dispersed core particle powder-
Dispersing step to form gas mixture, (B) Hollow member, member forming hollow, unavoidable for transportation of particles of highly dispersed core particle powder and particles of gas mixture core particle powder dispersed in this dispersing step A transporting step of transporting through an intermediate member consisting of and one or more members selected from a pipe,
(C) The degree of dispersion β of the particles of the highly-dispersed core particle powder and the particles of the gas-core mixture of the gas mixture carried in this carrying step is 70
A coating method comprising a coating step of contacting and / or colliding with the coating forming material precursor in the coating starting region of the coating space to start coating in a dispersed state of not less than%.

V (A) Fine particles having a volume-based frequency distribution and an average particle diameter of 10 μm or less Fine particles of core particle powder or particles of core particle powder mainly composed of fine particles were dispersed by means of a fine particle high dispersion treatment means group. Particles of highly dispersed core particle powder / particles of gas mixture core particle Fine particles that achieve a degree of dispersion β of 70% or more.
Dispersion and mixing step for forming a gas mixture, (B) High dispersion in which particles of highly dispersed core particle powder dispersed in this dispersion step / particles of core particle powder of gas mixture are dispersed in the air with this dispersion performance. Airborne dispersion maintaining means for maintaining the airborne dispersion state of the particles of the core particle powder / the particles of the gas mixture of the core particles, the particles of the highly dispersed core particle powder / the particles of the core particles of the gas mixture In-air dispersion promoting means for enhancing the air-dispersion state, low-dispersion core-particle powder particles in a mixture of core-particle powder particles and gas
Highly dispersed core particle powder particle / gas mixture that separates the gas mixture and selects the highly dispersed core particle powder particle / gas mixture in which the particles of the core particle powder mainly exist in the air in the form of a single particle. A carrying step of carrying through one or more kinds of selecting means, (C) the particles of the highly dispersed core particle powder and the particles of the core particle powder of the gas mixture carried in this carrying step have a dispersity β of 70 A coating method comprising a coating step of contacting and / or colliding with the coating forming material precursor in the coating starting region of the coating space to start coating in a dispersed state of not less than%.

In all of the above I to V, it is preferable that
A high-dispersion core particle powder obtained by dispersing particles of fine-particle core particle powder having an average particle diameter of 10 μm or less in a volume-based frequency distribution or particles of core particle powder mainly composed of fine particles by a fine particle high-dispersion treatment means group. All of the particles of the high-dispersion core particle powder / the particles of the core particle powder in the gas mixture within the spatial region where the degree of dispersion β of the core particle powder of the particle / gas mixture is 70% or more. The coating start region of the coating space is located in the space region including the surface through which the particles pass, or the fine particle core particles having an average particle diameter of 10 μm or less in the volume standard frequency distribution, or particles of mainly fine particles. The degree of dispersion β of the particles of the high-dispersion core particle powder / the gas of the core particle powder of the gas mixture in which the particles of the particle powder are dispersed by the fine particle high-dispersion processing means group is 70.
%, The coating start region of the coating space is located in a space region including a surface through which all particles are recovered in the recovery unit of the recovery means, or in the above I and II. , The volume-based frequency distribution has an average particle size of 10μ
Particles of a highly dispersed core particle powder in which particles of a core particle powder of m or less or particles of a core particle powder mainly composed of fine particles are dispersed by a group of means for highly dispersing fine particles. Of at least a part of the dispersion step of forming a particle / gas mixture of high-dispersion core particle powder by dispersing the particles in the air by means of a fine particle high-dispersion treatment means group that achieves a particle dispersity β of 70% or more. Part of or more is performed by sharing part or more of the space. According to the invention, the coated diamond powder particles or the mixture containing the particles obtained as described above are not metastable but thermodynamically stable but not pressure less than 2000 MPa and not exceeding 1850 ° C. for diamond. It is sintered under pressure and temperature sintering conditions to obtain a diamond sintered body.

When a substance exhibiting another function such as toughness enhancement is added, this substance is in the form of powder, plate or particles, and more specifically, the periodic table 1a, 2
a, 3a, 4a, 5a, 6a, 7a, 1b, 2b, 3
b, 4b, group 8 metals, semiconductors, semi-metals, rare earth metals,
And one or more selected from oxides, nitrides, carbides, oxynitrides, oxycarbides, carbonitrides, oxycarbonitrides, borides, and silicides, such as Al, B, Si, F
e, Ni, Co, Ti, Nb, V, Zr, Hf, Ta,
W, Re, Cr, Cu, Mo, TiAl, Ti ₃ Al,
TiAl ₃ , TiNi, NiAl, Ni ₃ Al, SiC,
_{B 4 C, Cr 3 C 2} , TiC, ZrC, WC, W 2 C, Hf
C, TaC, Ta ₂ C, NbC, VC, Mo ₂ C, Si ₃
N ₄ , TiN, ZrN, Si ₂ N ₂ O, AlN, HfN,
V _x N (x = 1 to 3), NbN, TaN, Ta ₂ N, Ti
B, TiB ₂ , ZrB ₂ , VB, V ₃ B ₂ , VB ₂ , Nb
B, NbB ₂ , TaB, TaB ₂ , MoB, MoB ₂ , M
oB ₄ , Mo ₂ B, WB, W ₂ B, W ₂ B ₅ , LaB ₆ , B
P, B ₁₃ P ₂ , MoSi ₂ , Al ₂ O ₃ , ZrO ₂ (Y
₂ O ₃ , MgO or CaO stabilizer added partially stabilized zirconia: PSZ or tetragonal zirconia polycrystal: T
ZP), MgAl ₂ O ₄ (spinel), and Al ₂ SiO ₅ (mullite).

Further, this substance may be a fibrous substance. The fibrous substance mixed with the coated diamond powder particles has a minor axis of 500 μm or less and a ratio of the major axis to the minor axis of 2 or more, and is a substance composed of at least one kind of metal or compound. Is less than 500 μm,
A rod-like substance having a shape in which the ratio of the major axis to the minor axis is 2 or more, and / or the continuous fiber which is a continuous fiber formed into a fiber shape by melt spinning and / or the short fiber which is a self-shaped fiber in which the crystal itself has a fiber shape. And / or unidirectionally crystallized whiskers in the form of fibers. It is defined that whiskers (whisker crystals) do not undergo the phenomenon of phase change or chemical reaction affecting the entire volume in the formation of the whiskers and / or phase change or chemical changes affecting the entire volume. By growing only one crystal plane of the generated crystal, a whisker in a broad sense and / or a cross-sectional area that indicates a single crystal that has become a long needle crystal is 8 ×.
There are whiskers that are single crystals with a length of 10 ⁻⁵ in ² or less and a length of 10 times or more the average diameter.

As the fibrous substance, the periodic table 1a, 2
a, 3a, 4a, 5a, 6a, 7a, 1b, 2b, 3
b, 4b, 5b, 6b, 7b, group 8 metal, semiconductor, semi
A compound containing one or more of metals, rare earth metals and non-metals
Includes at least one type of thing. Minor axis is 500 μm or less
And the shape of the fiber is such that the ratio of the major axis to the minor axis is 2 or more.
Substances are used. Specifically, the periodic table 1a, 2
a, 3a, 4a, 5a, 6a, 7a, 1b, 2b, 3
b, 4b, group 8 metals, semiconductors, semi-metals, rare earth metals,
And its carbides, oxides, nitrides, oxycarbides, oxynitrides
Of materials, carbonitrides, oxycarbonitrides, borides, silicides
The shortest diameter is 500 μm or less, which is also made of one type.
Use a fibrous substance with a ratio of 2 or more
To be done. Preferably, for example, Al, B, Si, Fe, N
i, Co, Ti, Nb, V, Zr, Hf, Ta, W, R
e, Cr, Cu, Mo, TiAl, Ti₃Al, TiA
l₃, TiNi, NiAl, Ni₃Al, SiC, B
_FourC, Cr₃C₂, TiC, ZrC, WC, W ₂C, Hf
C, TaC, Ta₂C, NbC, VC, Mo₂C, Si₃
N_Four, TiN, ZrN, Si₂N₂O, AlN, HfN,
V_xN (x = 1 to 3), NbN, TaN, Ta₂N, Ti
B, TiB₂, ZrB₂, VB, V₃B₂, VB₂, Nb
B, NbB₂, TaB, TaB₂, MoB, MoB₂, M
oB_Four, Mo₂B, WB, W₂B, W₂B_Five, LaB₆, B
P, B₁₃P₂, MoSi₂, Al₂O₃, ZrO₂(Y
₂O₃Partially stabilized diamine with added MgO, MgO or CaO stabilizer
Luconia: PSZ, or tetragonal zirconia polycrystal: T
ZP), MgAl₂O_Four(Spinel), Al₂SiO_Five(Mu
Light)) with a minor axis of 500μ
A fiber having a shape in which the ratio of the major axis to the minor axis is 2 or more when m or less.
Fibrous material can be selected.

The coated diamond particles used in the present invention are
As described above, since the surface is coated by the vapor phase method, there is basically no limitation on the coating forming substance. If necessary, in designing the material of the coated diamond sintered body according to the application, the same kind and / or different kinds of coating forming substances may be formed in advance on the surface of the diamond powder particles before applying the coating. /
Alternatively, the coating may be applied by a different coating method. For example, when forming a coating made of a target metal carbide on the surface of diamond particles, coated diamond particles coated with carbon in advance may be used. The method of coating the substance in advance is not particularly limited, but for example,
The molten salt dipping method described in JP-A-2-252660,
Starting with the molten salt disproportionation reaction method described in JP-A-1-207380, electroplating, electroless plating, cladding, physical vapor deposition (sputtering, ion plating, etc.), chemical vapor deposition, etc. Is preferred. The type of metal of the target metal compound is not particularly limited as long as it is a range applicable as the binder and / or the sintering aid of the present invention.

The coating film formed by the dipping method using the above molten salt is a substance having a high hardness and a high melting point. It is difficult to sinter densely only with diamond powder particles provided with a coating film by the dipping method using this molten salt, and in order to enable dense sintering, the dipping method using this molten salt The diamond powder particles coated with a coating film of a high hardness and a high melting point substance formed by the above method are further bonded to each other by a coating method by the vapor phase method of the present invention, which is sufficiently dense and can be sintered to a high hardness. It is necessary to coat an appropriate amount of material applicable as a material.

The above-mentioned coated diamond particles may form an agglomerate in contact with each other via the coating forming substance of the coated particles. The powder consisting of the coated diamond particles is composed of the coated particles in the state of a single particle, an agglomerate of the coated particles in the state of a single particle contacting from several to several tens, and a large number of single particles. It is composed of agglomerates in which coated particles in a single particle state are in contact with each other, and their shape and size are nonuniform and irregular. The agglomerate composed of the coated particles in a single particle state is preferably crushed and / or crushed and then subjected to a molding or sintering treatment. Various crushing means such as a ball mill, a vibrating ball mill, a mortar, and a jet mill can be used for crushing and / or crushing the coated aggregate of diamond particles. In addition, the coated particles in the single particle state and the aggregate of the coated particles in the single particle state are selectively separated, and only the coated particles in the single particle state are subjected to molding or sintering treatment. May be offered.

According to the present invention, on the surface of diamond particles,
By the gas phase method, the coated diamond particles coated with the coating-forming substance alone, or with the coated diamond particles, the rest is the powder, the plate-like substance, a mixture of particles and / or the fibrous substance, Sintered in powder form or after molding. Particularly high-purity diamond, for example, diamond synthesized through a vapor phase by PVD method or CVD method,
Alternatively, if diamond that has been synthesized at ultra-high pressure for a long time is used, it will be degassed and encapsulated in a capsule that can transmit pressure.
By performing IP sintering or HIP sintering, or by performing PC sintering or HP sintering in a vacuum or an inert gas, even if the thermodynamically stable state is not obtained, 1100 of the above-mentioned report by Mr. Hall. Diamond is practically stable up to 1850 ° C, which is much higher than 0 ° C. However, 1850 ° C
When it exceeds, a phase transition to a graphite phase occurs in a short time. Therefore, the upper limit of the sintering temperature is 1850 ° C.

As described above, the present invention is a coating using a PC type ultra high pressure device, an ultra high pressure HIP device, a HIP device, or an HP device capable of operating a relatively gentle ultra high pressure of less than 2000 MPa. Regarding the production of the high hardness and high density composite sintered body containing diamond, the upper limit of the sintering temperature is 1850.
C, and that in the sintering temperature range, it is not necessary to clarify the application conditions of the binder and to apply a pressure to bring the diamond into a thermodynamically stable state. , To be explicit. Therefore, when using a PC type ultra high pressure device, the pressure is 20
Although it is acceptable to apply less than 00 MPa, it is preferable that it does not exceed 1500 MPa in consideration of durability of this PC type ultra high pressure device. As a conventionally known technique regarding pressure generation, in the case of an ultra-high pressure HIP device, H up to 1000 MPa
The IP pressure can be applied, and the HIP device and the HP device other than the ultra-high pressure HIP device can operate up to 200 MPa, respectively.

The coated diamond sintered body sintered by the above method is a high-performance sintered body having a highly controlled microstructure. For the most common mechanical parts, the coated diamond sinter has a Vickers hardness of 1
It is possible to manufacture a dense coated diamond sintered body having a high hardness of 500 or more and a density of 90% or more. The coated diamond sintered body preferably has a Vickers hardness of 2
High hardness of 000 or more and / or its density is 95%
The dense coated diamond sintered body described above can be manufactured. More preferably, in consideration of application to a machine member having high wear resistance, for example, a diamond having a high Vickers hardness of 2500 or more can be obtained by relatively increasing the content of diamond and sintering it densely. A sintered body can be manufactured. For tools that require even greater wear resistance,
By further increasing the content of diamond and sintering it densely, a coated diamond sintered body having a Vickers hardness of 3000 or more can be manufactured.

[0102]

EXAMPLES The coated diamond sintered body of the present invention and the method for producing the same will now be described with reference to Examples. Example 1 The average particle size D _M is 1 μm, and the volume-based frequency distribution is ([D _M
/ 2,3D _M / 2], ≧ 90%) was coated with alumina, which is an oxide of aluminum metal.
The apparatus used is that shown in FIG. 7 and FIG. 8 which is a partially enlarged view thereof, and is a specific example of the configuration shown in FIG. The apparatus of this example includes a plasma torch 3-A, a plasma chamber 3-a, a cooling tank 3-B for the coating material precursor production chamber,
Coating forming substance precursor generation chamber 3-b, narrowly-defined coating chamber cooling tank 3-C, narrowly-defined coating chamber 3-c, coating particle cooling chamber cooling tank 3-D, coated particle cooling chamber 3-d, coating formation On the supply side of the raw material of the substance, the supply device 3-E1, the supply side of the core particle powder,
Stirring Disperser 3-F1 and Ejector Disperser 3-H
1. A capillary disperser 107 and a coated particle recovery unit 3-G. The supply device 3-E1 is connected to the supply tank 112 for the raw material powder of the coating-forming substance, and the stirring-type disperser 3-F1 is connected to the supply device 111 equipped with the supply tank for the core particle powder. By definition, the coating chamber in this example is composed of a plasma chamber 3-a, a coating-forming-substance precursor generation chamber 3-b, a coating chamber 3-c in a narrow sense, and a coating particle cooling chamber 3-d. Is called a coating room in a broad sense. Of the coating chambers in this broad sense, the chamber 3-c in which the coating process is mainly performed is called the coating chamber in the narrow sense.

Fine particle high dispersion treatment means group α in this example
Is a feeder 111 having a feed tank, a stirring type dispersing machine 3-F
1 and an ejector type disperser 3-H1 and a stainless steel capillary disperser 107 having an inner diameter of 4 mm, as shown in FIG.
4B, which is a specific example of the fine particle high dispersion treatment means group belonging to the configuration shown in FIG. 4B. The fine particle high-dispersion treatment means group has a D _{M of} 1 μm ([D _M / 5,5D _M ], ≧
90%) of the core particles of diamond particles, β ≧ 70% can be realized at the time of output. The thin tube 107, which is the final processing means of the fine particle high-dispersion processing means group, is directly connected to the coating chamber 3-C, and is configured so that β ≧ 70% can be realized in the coating start region 3-L1 of 3-L2 of the coating space. Has been done.

Argon gas was supplied from the supply source 102 to the gas jet port 101 provided on the upper part of the plasma torch 3-A.
Supply at a rate of 0 liters / minute. The argon gas is turned into plasma by the applied high frequency, and forms a plasma flame in the plasma chamber 3-a in the plasma torch 3-A. Feeder 112 equipped with a feed tank for the raw material of the coating forming substance
Average particle size of 2μ which is the raw material of the coating forming material supplied from
m of alumina powder is 5 l / min of carrier gas 1
No. 03, and was introduced into the plasma flame at a rate of 1.5 g / min from the feed port 104 for the raw material of the coating forming material provided in the lower part of the plasma torch 3-A, and was evaporated by the heat of the plasma flame. After passing through the gas phase, it becomes a coating material precursor in the coating material precursor production chamber 3-b. Diamond core particles having an average particle diameter of 1 μm, which are supplied at 0.3 g / min from a feeder 111 equipped with a core particle powder supply tank, are dispersed by a stirring type dispersing machine 3-F1 and 5 liters / minute. It is supported by the carrier gas 105 supplied at a ratio of 10
The ejector type disperser 3-H1 and the narrow tube disperser 107 using the dispersion gas 106 at a flow rate of 1 / min are dispersed into a dispersion state having a dispersity β = 82% and introduced into the coating chamber.
Highly dispersed diamond particles have 3-L2 in the coating space.
In the coating start region 3-L1 of (1), contact and / or collision start with the coating material precursor in a dispersed state of β = 82%.
The coated diamond particles having the surfaces coated with the coating-forming substance, generated in this way, descend in the coated particle cooling chamber 3-d together with the gas and reach the coated particle recovery unit 3-G. A product consisting of this coated particle is a filter 110.
Are separated from the gas by means of and are collected and taken out. Thus, coated particles in which the diamond particles were coated with 70% by volume of alumina were obtained.

The obtained coated diamond particles, ie, the diamond fine particles whose surface was coated with alumina, were observed by a scanning electron microscope. As a result, as shown in FIG. Alumina of about 0.005 μm was coated in the form of ultrafine particles. The coated diamond particles were embossed into a disc shape with a diameter of 16 mm and a thickness of 5 mm, and the compact was placed in a capsule made of Pyrex glass filled with h-BN powder.
After degassing for 12 hours at 0 ^-6 torr and 400 ° C., it was sealed. This capsule was placed in a HIP apparatus using argon gas as a pressure medium, and the sintering temperature was 1200 ° C. and the sintering pressure was 150 MPa.
Hold for time and sinter. Thereafter, the furnace was cooled, the pressure was released, and the sintered body was taken out. When the crystal phase of the sintered body of Example 1 was examined by powder X-ray diffraction, diffraction peaks other than those of diamond and α-type alumina were not recognized. As shown in Table 1 below, the sintered body is very dense with a density of 96.0% and has a Vickers microhardness of Hv.
The hardness was (0.5 / 10) 2740, which was a very high hardness.

FIG. 10 shows an electron micrograph (× 5000) of a polished surface obtained by polishing the surface of the obtained sintered body with a diamond paste and subjecting the polished surface to ordinary gold vapor deposition for observation. In the figure, the dark areas are diamonds and the light areas are alumina binders. From this figure, it can be seen that there is no unsintered part, pores, defects, etc., and it has a highly controlled microstructure in which alumina as a binder is uniformly distributed around the diamond particles.

On the other hand, as in the comparative example, uncoated diamond particles and alumina powder were mixed in a volume of 70% like the one used in the example, and the mixture was sintered under the same conditions as in this example. The density of the aggregate was 92%, the Vickers microhardness was 2200, and an electron micrograph (× 5000) of the polished surface of the sintered surface of this sintered body which had been subjected to ordinary gold vapor deposition for observation (Fig. Compared with 11), the difference can be clearly seen. That is, in the diamond sintered body of the comparative example, the distribution of the binder and the sintering aid is irregular, and the binder and the sintering aid are in some places in the form of lumps. There are not a few deficient auxiliary agents and binders, and there are unsintered parts. As described above, the sintered body of Example 1 of the present invention was very excellent in density, hardness and microstructure as compared with Comparative Example.

Example 2 The average particle size D _M is 1 μm, and the volume-based frequency distribution is ([D _M
/ 2,3D _M / 2], ≧ 90%) was coated with alumina. The apparatus used is that shown in FIG. 12 and FIG. 13 which is a partially enlarged view thereof, and FIG.
It is a specific example of the configuration shown in FIG. The configuration of the apparatus for producing the coating material precursor of this example is the same as that of the first embodiment. The fine particle high-dispersion processing means group α is a feeder 21 equipped with a feed tank.
4, a stirring type disperser 5-F1, a capillary disperser 211, and a disperser 5-H2 using a collision plate.
FIG. 4A is a specific example of a group of means for high-dispersion fine particle treatment belonging to the structure shown in FIG. 4B. The thin tube disperser 211 is made of stainless steel having an inner diameter of 4 mm. The disperser 5-H2 using the collision plate, which is the final dispersion means of the fine particle high dispersion treatment means group α, has a structure in which a collision plate 213 made of SiC is installed by a holder 212 made of stainless steel. The dispersing machine 5-H2 using this collision plate is a coating chamber 5-in a narrow sense.
The fine particle high-dispersion processing means group α and the coating chamber 5-c in a narrow sense, which are provided in c, have a common space. Also,
Covering space 5-L1 and coating start region 5-L2 of the covering space
Is provided in the narrowly-defined coating chamber 5-c. The group of means for high-dispersion fine particles of this apparatus has a mean particle diameter D _M of 1 μm and a core particle powder having a volume-based frequency distribution ([D _M / 5,5D _M ], ≧ 90%) Immediately after the collision, the collision plate 215 of the disperser 5-H2 using the collision plate, which is the dispersion processing of No. 1, can be dispersed to the degree of dispersion β ≧ 70%. Therefore, the degree of dispersion β ≧ 7
The coating starts at 0%.

20 l / min of argon gas is supplied from the supply source 202 to the gas ejection port 201 provided on the upper part of the plasma torch 5-A. This argon gas is turned into plasma by the applied high frequency, and the plasma torch 5
-A plasma flame is formed in the plasma chamber 5-a in A. 1. From a feeder 215 equipped with a feed tank for the raw material of the coating forming material.
Alumina powder having an average particle diameter of 2 μm, which is the raw material of the coating forming substance supplied at 0 g / min, was carried by the carrier gas 203 at 5 liters / min, and the coating forming substance provided below the plasma torch 5-A. It is introduced into the plasma flame from the raw material charging port 204, evaporated by the heat of the plasma flame, and passes through the gas phase to become the coating substance precursor in the coating substance precursor generation chamber 5-b. Diamond core particles supplied at 0.7 g / min from a feeder 214 equipped with a core particle powder supply tank are dispersed by a stirring type dispersing machine 5-F1 and supplied at a rate of 20 liters / minute. The carrier gas 205 is carried, and after passing through the narrow tube disperser 211, the disperser β-82% is dispersed in the air by the disperser 5-H2 using the collision plate provided in the coating chamber. The highly dispersed diamond core particles and β = 82 with the coating material precursor in the coating start region 5-L1 of the coating space 5-L2.
% And start to contact and / or collide with the dispersed state.

The coated diamond particles having the surface coated with the coating-forming substance, produced in this manner, are:
Along with the gas, the coated particle cooling chamber 5-d descends and reaches the coated particle recovery unit 5-G. The product consisting of the coated diamond particles is separated from the gas by the filter 210,
Collected and taken out. Thus, coated particles in which the diamond particles were coated with 50% by volume of alumina were obtained. The obtained coated particles, that is, the diamond fine particles whose surfaces were coated with alumina, were observed by a scanning electron microscope.
Alumina of about 5 μm was coated in the form of ultrafine particles. Coated diamond particles obtained by coating 50% by volume of the alumina thus obtained were embossed into a diameter of 8 mm and a thickness of 5 mm, which was then molded into a Pyrex glass capsule similar to that of Example 1. It was placed, degassed by heating, and then sealed. Then, using an ultra-high pressure HIP device, sintering was carried out at a sintering temperature of 1200 ° C. and a sintering pressure of 1000 MPa for 3 hours. When the crystal phase of the sintered body of Example 2 was examined by powder X-ray diffraction, diffraction peaks other than those of diamond and α-type alumina were not recognized. As shown in Table 1, the sintered body was very dense with a density of 95.0%, and had a Vickers microhardness of Hv (0.5 / 10) 3350.
It was very high hardness. Further, as in Example 1, a sintered body having a highly controlled microstructure in which alumina was uniformly distributed around the diamond was obtained.

Example 3 The average particle size was 1 μm, and the volume-based frequency distribution was ([D _M /
2,3D _M / 2], ≧ 90%) diamond particles were coated with alumina. The apparatus used is that shown in FIG. 14 and FIG. 15 which is a partially enlarged view thereof, and is a specific example of the configuration shown in FIG. 6 (b). The configuration of the apparatus for producing the coating material precursor of this example is the same as that of the first embodiment. The particle high-dispersion processing means group α includes a feeder 313 equipped with a feeding tank,
A stirring type disperser 6-F1 as a dispersing means, and a cyclone 6-I as a means for selecting a particle / gas mixture of highly dispersed core particle powder.
4 and is the same as that shown in FIG. 3B.
It is a specific example of the configuration shown in (d). The discharge part of the particle / gas mixture of the high-dispersion core particle powder of the cyclone 6-I is connected to the coating chamber 6-c in a narrow sense by a pipe 307 which is inevitable for transportation, and discharge of the low-dispersion core particle powder portion. Part is hopper 6
It is connected to the stirring type dispersing machine 6-F1 through the carrier pipe 310 via the -J and rotary valve 6-K. According to the fine particle high-dispersion treatment means group of the present apparatus, as the volume-based particle size distribution, the average particle diameter D _M is 1 μm, and the volume-based frequency distribution is ([D _M / 5,5D _M ], ≧ 90%). Cyclone 6 which is the final processing means for the particles of diamond core particle powder
Dispersion degree β ≧ 75 at the discharge part of the highly dispersed core particle powder flow of −I
% Can be dispersed. A coating space 6-L2 and a coating start region 6-L1 of the coating space are provided in the coating chamber 6-c in a narrow sense as shown in the figure. The decrease in the degree of dispersion β due to the pipe 307, which is unavoidable for the transportation due to the restriction of the flange portion connecting the 6-C and 6-D, is limited. Therefore, in the coating start region, the coating starts with the degree of dispersion β ≧ 70%.

Argon gas is supplied from the supply source 302 to the gas jet port 301 provided on the upper part of the plasma torch 6-A.
Supply at 0 l / min. This argon gas is turned into plasma by the applied high frequency, and the plasma torch 6
-A plasma flame is formed in the plasma chamber 6-a in A. From a feeder 314 equipped with a feed tank for the raw material of the coating forming material.
Alumina powder, which is a raw material of the coating forming material supplied at 6 g / min, is carried by a carrier gas 303 of 5 liters / min, and an inlet 304 of the raw material of the coating forming material provided in the lower portion of the plasma torch 6-A. Is introduced into the plasma flame, vaporized by the heat of the plasma flame, passes through the gas phase, and becomes the coating substance precursor in the coating substance precursor generation chamber 6-b. Feeder 313 to 1.5 equipped with a supply tank for core particle powder
The diamond core particles supplied at g / min are dispersed by the stirring type disperser 6-F1, carried by the carrier gas 305 at 15 l / min, and conveyed to the cyclone 6-I through the pipe 306. Cyclone 6-I is adjusted so that the maximum particle size on the fine powder side is 1.5 μm, and it is composed mainly of single particles β / 85% highly dispersed core particles The mixture is conveyed from the discharge port 308 through a pipe 307 which is inevitable for transportation to the coating chamber 6 in a narrow sense.
Let c release it. On the other hand, the low-dispersion core particle powder portion selectively separated by the cyclone 6-I is conveyed through the pipe 310 by the carrier gas 309 of 10 l / min through the hopper 6-J and the rotary valve 6-K, and the stirring type Feedback to the disperser 6-F1. The highly dispersed diamond core particles start contact and / or collision with the coating material precursor in the coating start region 6-L1 of the coating space 6-L2 in a dispersed state of β = 82%.

The thus-produced coated diamond particles, the surface of which is coated with the coating-forming substance, are:
Along with the gas, the coated particle cooling chamber 6-d descends to reach the coated particle recovery unit 6-G. The product consisting of the coated diamond particles is separated from the gas by the filter 312,
Collected and taken out. In this way coated diamond particles were obtained in which the diamond particles were coated with 50% by volume of alumina. Observation of the obtained coated diamond particles, that is, the diamond fine particles whose surface was coated with alumina, with a scanning electron microscope revealed that the individual particles were uniformly ultrafine alumina particles of about 0.005 μm. It was coated in a shape. Coated diamond powder particles obtained by coating 50% by volume of the obtained alumina with a diameter of 10 mm and a thickness of 8 mm were embossed and embedded in a pyrophyllite pressure medium having an h-BN compact on the outside, which was then used as a piston. -It was set in a cylinder (PC) type ultra-high pressure apparatus, held at a sintering temperature of 1200 ° C and a sintering pressure of 1500 MPa for 3 hours and sintered. After that, the temperature was lowered and the pressure was lowered to take out the sintered body. No powder diffraction peaks other than diamond and α-type alumina were observed in the sintered body by powder X-ray diffraction. As shown in Table 1, the sintered body was very dense with a density of 95.3%, and had a very high Vickers hardness of Hv (0.5 / 10) 3380. Further, as in Example 1, a sintered body having a highly controlled microstructure in which alumina was uniformly distributed around the diamond was obtained.

Example 4 Coated diamond particles coated with alumina in a volume of 50% obtained by coating with the apparatus of Example 1 under substantially the same conditions as in Example 1 had a diameter of 10 mm and a thickness of 8mm in length, embossed in a pyrophyllite pressure medium with an h-BN compact on the outside, set this in a piston-cylinder (PC) type ultra-high pressure device, and sintering temperature 1
Sintering was performed at 300 ° C. and a sintering pressure of 1500 MPa for 3 hours. After that, the temperature was lowered and the pressure was lowered to take out the sintered body. By powder X-ray diffraction, no diffraction peak other than diamond and α-type alumina was observed in any of the sintered bodies. As shown in Table 1, each sintered body has a density of 9
It was very dense at 5.5%, and the Vickers microhardness was Hv (0.5 / 10) 3400, which was a very high hardness. Further, as in Example 1, a sintered body having a highly controlled microstructure in which alumina was uniformly distributed around the diamond was obtained.

Examples 5 to 7 Inorganic salts consisting of KCl, BaCl ₂ and NaF,
TiO ₂ and ferroalloy (Fe-Ti) immersion method using a molten salt immersion bath by adding the (disproportionation reaction method), diamond powder particles (particle size 0～2Myuemu), 90
Dip coating was carried out at 0 ° C. for 1 hour, and the surface of the diamond powder particles was coated with titanium carbide (TiC) in an amount of 5% by volume added by internal addition. Furthermore, on this surface, Example 1
Coating is performed under substantially the same conditions as in Example 1 by
Alumina was applied to cover 45% to 35% by volume to obtain coated diamond particles. Sintering conditions 1500MP
a, 1200 ° C. to 1300 ° C. for 3 hours to 6 hours, and sintering was performed in the same manner as in Example 4. Example 5 by powder X-ray diffraction
When the crystal phase of the sintered body of Example 7 was examined, diamond, titanium carbide and α-type alumina were observed, and no other diffraction peak was detected. In each of Examples 5 to 7, it was difficult to form a polishing surface during the preparation of the polishing surface for hardness measurement, and the abrasion resistance was high. Examples 5 to 7
It is considered that the wear resistance was enhanced by forming the titanium carbide coating film by dip coating in each case. As shown in Table 1, the sintered body is very dense with a density of 94.8% to 95.0% and has a Vickers microhardness of Hv.
(0.5 / 10) 3670 to 3730, which was a very high hardness. Further, as in Example 1, a sintered body having a highly controlled microstructure in which a binder made of titanium carbide and α-alumina was uniformly distributed around the diamond was obtained.

Example 8 to Example 9 As in Example 5, titanium carbide (TiC) was added internally by the dipping method using a molten salt bath, and the addition amount was 5% by volume.
Coated diamond powder particles (particle size 0 to 2μ
m) on the surface, and further by the apparatus of Example 1,
The coating is performed under substantially the same conditions as above, and PSZ is 40 to 4 in volume.
Coated diamond particles with a 5% coating were obtained. The sintering conditions were 1500 MPa and 130 as in Example 5.
Sintered at 0 ° C for 3-6 hours. When the crystal phase of the sintered body was examined by powder X-ray diffraction, diffraction peaks of monoclinic zirconium oxide and tetragonal zirconium oxide constituting diamond, titanium carbide, PSZ were observed, and other diffraction peaks were observed. I couldn't do it. As shown in Table 1, the sintered body is very dense with a density of 99.3 to 99.6%, and has a Vickers microhardness of Hv (0.5 / 1).
0) 2120 to 2360, which was a very high hardness. Also,
As in Example 1, titanium carbide, P
A sintered body having a highly controlled microstructure in which the binder made of SZ was uniformly distributed was obtained.

Examples 10 to 11 As in Examples 1 and 2, coated alumina powder obtained by coating alumina was coated with 50% to 70% by volume of coated diamond powder, and SiC. The whisker mixing ratio was set to 90:10 by volume, and an alumina ball mill was used.
The mixture was wet mixed in acetone for 2 hours. After that, 10 ^-6 t
The mixture was vacuum dried at orr, 200 ° C. Then, the preparation was carried out in the same manner as in the production methods of Example 1 and Example 2, and thereafter,
Using a HIP device or an ultra-high pressure HIP device, sintering was performed at a sintering temperature of 1200 ° C. and a sintering pressure of 150 MPa to 1000 MPa for 3 hours. When the crystal phases of the sintered bodies of Examples 10 to 11 were examined by X-ray diffraction, no diffraction peaks other than those of diamond, α-type alumina and silicon carbide were observed. As shown in Table 1, the sintered body has a density of 94.0% to
It was very dense at 94.8%, and had a very high Vickers hardness of Hv (0.5 / 10) 2660 to 3220. Further, a sintered body having a highly controlled microstructure was obtained in which the SiC whiskers were uniformly dispersed around the coated diamond particles, and further, the binder alumina was uniformly distributed around the diamond particles.

Example 12 By using the apparatus of Example 1, coating was performed under substantially the same conditions as in Example 1 to obtain coated diamond powder particles in which 55% by volume of alumina was coated. In addition, the surface of the SiC whiskers was coated with titanium carbide (TiC) as a target by a sputtering method in an amount of 33% by volume added by internal addition. The volume ratio of the two is 85:
15, and mixed and dried in the same manner as in Examples 10 to 11. Then, it was sintered in the same manner as in Example 9. When the crystal phase of the sintered body was examined by powder X-ray diffraction, no diffraction peaks other than those of diamond, α-type alumina, silicon carbide and titanium carbide were observed. As shown in Table 1, the sintered body had a density of 95.1% and was extremely dense, and had a Vickers microhardness of Hv (0.5 / 10) 3170, which was a very high hardness. Sintered body is SiC coated with TiC
A highly controlled microstructured sintered body was obtained in which the whiskers were uniformly dispersed around the alumina-coated diamond particles, and the binder alumina was evenly distributed around the diamond particles.

[0119]

[Table 1]

[0120]

According to the present invention, a core particle powder composed of diamond fine particles having an average particle size of 10 μm or less in a volume-based frequency distribution is dispersed in the air, and the dispersed core particle powder particles are dispersed. It contains coated diamond particles or the same particles whose surface is coated with a coating-forming substance in a single particle state by contacting or colliding with the coating-forming substance precursor in a dispersed state having a degree β of 70% or more. The mixture
Diamond is not thermodynamically stable at a pressure of less than 2000 MPa and not more than 1850 ° C., but it is uniformly and densely produced by sintering under a sintering condition of metastable pressure and temperature.
In addition, it is possible to obtain a high-performance coated diamond sintered body that is strongly sintered and has a highly controlled microstructure.
The restriction drawback of using an ultrahigh pressure generator for producing an ultrahigh pressure of 000 MPa or more is solved. In particular, when an ultra-high pressure HIP device or an HIP device other than the ultra-high pressure HIP device is used, it is possible to manufacture a sintered body having a more complicated shape, which is a great advantage in industrial production.

[Brief description of drawings]

FIG. 1 is a pressure / temperature diagram showing a stable region of diamond.

FIG. 2 is a distribution chart of powder particles, (a) represents the degree of dispersion β, and (b) is 90% by volume of particles having a particle size range of D _{1 to} D _2.
Represents the frequency based on the particle size of the powder occupying the volume.

3 (a) to 3 (c) are block diagrams showing the basic configuration of a group of means for highly dispersing fine particles.

4 (a) to (g) are block diagrams for explaining the configuration of a fine particle high dispersion treatment means group in more detail.

5 (a) to 5 (e) are views showing a mode in which coating of core particle powder is started.

6 (a) to 6 (g) are block diagrams illustrating the configuration of an apparatus for producing coated diamond particles.

FIG. 7 is a diagram showing an apparatus used in Example 1.

FIG. 8 is a partially enlarged view of the device used in the first embodiment.

9 is a scanning electron micrograph of coated diamond particles obtained in Example 1. FIG.

10 is an electron micrograph of a polished surface of the sintered body of Example 1. FIG.

FIG. 11 is an electron micrograph of a polished surface of a diamond sintered body of a comparative example.

FIG. 12 is a diagram showing an apparatus used in Example 2;

13 is a partially enlarged view of the device used in Example 2. FIG.

FIG. 14 is a diagram showing an apparatus used in Example 3;

FIG. 15 is a partially enlarged view of the apparatus used in Example 3.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Haruo Yoshida Inventor Haruo Yoshida No. 1 Onoue-cho, Kita-ku, Nagoya-shi, Aichi Room No. 1406, No. 5 Building, Onoue housing complex (72) Inventor, Kasomasa City Kabushika-cho, Tsushima City, Aichi Prefecture 2 of 150 Ninowari (72) Inventor Yuki Yamada 3-6-18 Hachiman, Kawashima-cho, Hiki-gun, Saitama Prefecture (72) Tadashi Fuyuki 2-23-16 Midorigaoka, Oi-cho, Iruma-gun, Saitama Prefecture (72) Inventor Satoshi Akiyama 17-22 Inaricho, Kawagoe-shi, Saitama Prefecture (72) Inventor Miaki Hamada 3-4 Suehiro-cho, Kawagoe-shi, Saitama Prefecture (72) Eisuke Kuroda 2 Nishikosenba-cho, Kawagoe-shi, Saitama Prefecture No. 16-4 (72) Inventor Tadakatsu Nabeya 1095-21 Yamanouchi, Kamakura City, Kanagawa Prefecture (72) Inventor Yukio Sumida 55-520 Nakahara, Yoshida, Watari Town, Watari District, Miyagi Prefecture (72) Kenichi Kimura Sendai City, Miyagi Prefecture 2 Yagiyamahonmachi, Taishiro-ku −33−5 Grace Yagiyama No.502

Claims (8)

[Claims] 1. A diamond is obtained by sintering core particle powder particles composed of diamond particles or particles of core particle powder composed mainly of the same particles, the surfaces of which are coated with a coating-forming substance. In the method for producing a sintered body, the diamond particles coated with the coating forming substance are obtained by introducing the core particle powder into the coating space and generating the coating forming substance precursor and / or the vapor phase state through the gas phase. A coating forming substance precursor is brought into contact with and / or colliding with the particles of the core particle powder to coat the surface of the particles of the core particle powder with the coating forming substance. The final processing means of the distributed processing means group is
(A) Dispersing means for dispersing the particles of the core particle powder in the air, and (b) Low dispersion in a mixture of the particles of the core particle powder and the gas in which the particles of the core particle powder are dispersed in the air. Highly dispersed core particle powder particles that separate the core particle powder part and select the particle / gas mixture of highly dispersed core particle powder in which the particles of the core particle powder mainly exist in the air in a single particle state. A gas mixture selecting means and particles of the high-dispersion core particle powder, a low-dispersion core particle powder portion selectively separated by the gas-mixture selecting means, and a final dispersing means among the dispersing means in the fine particle high dispersion treatment means group And / or particles of highly dispersed core particle powder provided with feedback means for conveying to the processing means before the final dispersion means
An average particle diameter of 10 μm in a volume-based frequency distribution is obtained by a group of means for highly dispersing fine particles selected from a gas mixture selecting means.
The following dispersion step of dispersing the particles of the fine particle core particle powder or the particles of the core particle powder mainly composed of fine particles in the air to form a particle / gas mixture of the highly dispersed core particle powder, (B) this dispersion Coating in which the particles of the core particle powder dispersed in the step are contacted and / or collided with the coating material precursor in the coating start region of the coating space in a dispersed state having a dispersity β of 70% or more to start coating. And the coated diamond particles, or a mixture containing the same, at a temperature of 200.
A process for producing a coated diamond sintered body, which comprises sintering at a pressure of less than 0 MPa, and a diamond not exceeding 1850 ° C. which is not thermodynamically stable but metastable at a pressure and temperature. 2. The coated diamond particles crush and / or crush the agglomerates of coated diamond particles that have formed agglomerates in contact with each other through the coating forming substance of the coated diamond particles. It is prepared by further undergoing a crushing / crushing step of the coated diamond particle agglomerate and / or a selective separation step of selectively separating the coated diamond particle agglomerate and the coated diamond particles of the primary particle unit. Claim 1 characterized by the above.
The method for producing a coated diamond sintered body according to 1. 3. Particles of core particle powder consisting of diamond fine particles to be coated with a coating forming substance, or particles of core particle powder mainly consisting of the same fine particles, are immersed in a dipping method using a molten salt bath. The coated diamond according to claim 1 or 2, wherein the coated diamond is one or more particles of a core particle powder coated with a coating material derived from the core material or a core particle powder mainly composed of fine particles. Manufacturing method of sintered body. 4. The coated diamond particles are highly dispersed core particles in which core particle powder having a volume-based frequency distribution and an average particle diameter of 10 μm or less is dispersed in the air by a final treatment of a fine particle high dispersion treatment means group. A particle / gas mixture of powder is provided, and a dispersion process is carried out by means of a group of fine particle high-dispersion processing means having a dispersion performance of making the degree of dispersion β of the particles of the core particle powder 70% or more, and dispersed by the group of fine-particle high dispersion processing means The particles / gas mixture of the high-dispersion core particle powder thus obtained are directly discharged to the coating step, or the particles of the high-dispersion core particle powder dispersed by the fine particle high-dispersion treatment means group between the dispersion step and the coating step. From the discharge part for discharging the gas mixture, through one or more members selected from a hollow member, an intermediate member made of a member for forming a hollow, and a pipe, which is unavoidable for carrying, and / or Is an air-dispersion maintaining means for maintaining the air-dispersed state of the particles in the particle / gas mixture of the highly dispersed core particle powder dispersed in the air with the dispersion performance, and dispersed in the air with the dispersion performance. An air dispersion promoting means for increasing the air dispersion state of particles in a highly dispersed core particle powder / gas mixture, and a low dispersion core particle powder portion in a mixture of particles and gas of the core particle powder. The particles / gas mixture of the highly dispersed core particle powder for separating and selecting the particle / gas mixture of the highly dispersed core particle powder in which the particles of the core particle powder mainly exist in the air in a single particle state The method for producing a coated diamond sintered body according to claim 1, which is prepared by transporting via one or more kinds. 5. Highly dispersed core particles in which coated diamond particles have a core particle powder having a volume-based frequency distribution and an average particle diameter of 10 μm or less, which are dispersed in the air by the final treatment of a fine particle high dispersion treatment means group. A particle / gas mixture of powder, and a part of the dispersion step and a part of the above-mentioned coating step by means of a fine particle high-dispersion treatment means group having a dispersibility of 70% or more for the core particle powder The method for producing a coated diamond sintered body according to claim 1, wherein the above is prepared by sharing a part or more of the space. 6. Highly dispersed core particles in which coated diamond particles have a core particle powder having a volume-based frequency distribution and an average particle diameter of 10 μm or less, which are dispersed in the air by a final treatment of a fine particle high dispersion treatment means group. The particle / gas mixture of the powder, and the core particle powder in the gas / particle mixture of the highly dispersed core particle powder in the spatial region where the degree of dispersion β of the particle of the core particle powder is 70% or more. A coating start region of the coating space is located in a space region including a surface through which all of the particles pass, or a core particle powder having an average particle size of 10 μm or less in a volume-based frequency distribution is treated as a fine particle high dispersion treatment means. By means of the final treatment of the group, it is dispersed in the air to obtain a highly dispersed core particle powder in a particle / gas mixture, and the dispersion means β in the space region where the degree of dispersion β of the particles of the core particle powder is 70% or more. Including the surface through which all particles to be collected pass through Characterized in that the spatial region, are those prepared by allowed to position the coating start region of the coating space, according to claim 1, claim 4 or claim 5
The method for producing a coated diamond sintered body according to 1. 7. The particle size distribution of the particles of the core particle powder used is a volume standard frequency distribution ([D _M / 5,5D _M ], ≧ 90%) when the average particle size is D _M. 7. The method for producing a coated diamond sintered body according to claim 1, claim 4, claim 5 or claim 6, wherein: 8. A coated diamond sintered body produced by the method for producing a coated diamond sintered body according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6 or claim 7. body.