JP2672671B2 - Manufacturing method of composite particles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a method for producing composite particles, which has recently attracted attention as a new material in various industrial fields.

More specifically, the casing is rotated at a high speed, and a granular raw material composed of a mixture of a plurality of materials is pressed against the inner peripheral surface of the casing by a centrifugal force to form a raw material layer, and a grinding piece rotating relative to the casing. Is applied to the raw material layer to form composite particles in which the plurality of materials are integrated by compression and shearing by the milled pieces to improve the method for producing composite particles.

[Conventional technology]

Conventionally, as disclosed in Japanese Patent Laid-Open No. 63-42728, a compressive force and a shearing force are applied to a raw material only by a grinding piece and a casing, and a raw material is mixed and dispersed only by a scraping piece.

[Problems to be solved by the invention]

However, with a hard raw material such as metal, a sufficiently strong compressive force and shearing force cannot be evenly applied to the entire raw material layer, and the raw material cannot be sufficiently complexed. In the case where the front part is a granular material having a strong cohesive property, the mixing and dispersion are insufficient and the composition of the composite particles is likely to be non-uniform, and there is room for improvement in terms of expanding applicable raw materials.

The object of the present invention is to make the raw material hard,
Alternatively, it is to ensure that good composite particles can be obtained even if they have strong cohesiveness.

[Means for solving the problem]

The characteristic means of the present invention is to mix small particles for grinding media having a diameter smaller than the gap width between the grinding pieces and the casing into a raw material layer formed by centrifugal force on the inner peripheral surface of the casing, and to mix the grinding pieces and the grinding particles. The small particles for the medium and the casing cooperate to give a compressive force and a shearing force to the raw material, and the action and effect are as follows.

(Operation)

With the relative rotation of the milling piece with respect to the casing, the small particles for the grinding medium enter the gap between the milling piece and the casing together with the raw material, and between the grinding piece and the small particles for the milling medium, between the casing and the small particles for the milling medium. At a large number of locations between the small particles for grinding media, the raw material layer can be compressed and sheared in a state where the raw material layer becomes thin. Compared to applying a compressive force and a shearing force to a thick raw material layer in a ratio between the two, the compressive force and the shearing force can be sufficiently strengthened and can be evenly applied to the entire raw material layer, even if the raw material is hard like a metal. Even if it exists, it is possible to sufficiently and uniformly combine the raw materials.

In addition, if a scraping piece that rotates relative to the raw material layer and acts as a mixing / dispersing element is added, small particles for grinding media can be used when entering the gap between the grinding piece and the casing and when agitated by the scraping piece. Since the particles move relatively to the raw material layer, in addition to the mixing and dispersing by the scraping piece, the small particles for the grinding medium can sufficiently promote the mixing and dispersing of the raw material. Rather than mixing and dispersing the raw materials alone
The combined action of the scraping pieces and the small particles for grinding media can achieve more sufficient mixing and dispersion of the raw materials, and the composition of the composite particles can be ensured even if some or all of the raw materials have strong cohesiveness. Can be made uniform.

〔The invention's effect〕

As a result, it is possible to reliably obtain good composite particles even if they are hard materials such as metals or raw materials with strong cohesiveness, and a convenient method for producing composite particles with an extremely wide range of applicable raw materials. Was established.

〔Example〕

First, an embodiment of the apparatus used according to FIGS. 1 and 2 is shown.

A cylindrical casing (4) with a bottom that forms a processing chamber (3) at the upper end of a vertical rotation shaft (2) attached to a base (1).
Are mounted concentrically, and the electric motor (5a) and the transmission (5b)
A driving device (5) composed of the above is interlocked with the lower end of the rotating shaft (2), and the casing (4) is rotated at high speed so that the powdery material inside the casing (4) is pressed against the casing inner peripheral surface (4a) by centrifugal force. Therefore, the rotation speed of the casing (4) can be adjusted so that an appropriate centrifugal force can be obtained according to the properties of the raw material.

The casing (4) is surrounded by a cover (7), a fan (12) is connected to the lower part of the casing (4), and the outside air is sucked through an intake port (13) formed with the cover (7) to suck the outside air. By means of which the casing (4) is cooled, and also. A flow path (1 that connects the outside air to the cover (7)
It is configured so as to lead to a collector (15) and an exhaust fan (1).
6) is connected to the flow path (10) in that order, and a rotary feeder (17) for collecting fine powder is provided at the discharge port of the collector (15).

The cover (7) is provided with a lid (7a) that can be opened and closed, and the casing (4) is provided with a lid (4b) that can be opened and closed to supply the raw material into the casing (4) and from the casing (4). It is configured so that composite particles can be collected.

A support (8b) fixed to the upper end of a rotary shaft (8a) concentric with the rotary shaft (2) is provided in the casing (4), and the raw material is compressed in cooperation with the casing inner peripheral surface (4a). Attach the grinding pieces (9a) to be sheared and the scraping pieces (9b) to mix and disperse the raw materials with stirring at the tip of the support (8b) in a state where they are arranged at appropriate intervals in the rotational direction of the casing (4). It is located in the processing chamber (3).

The grinding piece (9a) has an inclined surface formed so that the gap between the grinding piece (9a) and the casing (4) becomes narrower toward the rotation direction side of the casing (4), and the scraping piece (9b) is attached to the casing (4). Is formed in a wedge shape or a comb tooth shape so that the gap between the two becomes wider toward the rotation direction side of the casing (4) and the working surface becomes gradually wider.

The rotating shaft (8a) is interlocked with the driving device (5), and the grinding piece (9a) and the scraping piece (9b) are relatively rotated with respect to the casing (4) at a constant speed difference, and the grinding piece (9a). It is configured so that the raw materials are subjected to compression and shearing by (1) and stirring and mixing by scraping pieces (9b).

A passage (18) for flowing a heating or cooling medium into the support (8b), grinding piece (9a) and scraping piece (9b) is formed in the rotating shaft (8a), and the passage is formed by the rotary joint (19). (18) is connected to the medium storage tank (20).
Further, a jacket (22) is provided around the cover (7) so that the medium for heating or cooling from the tank (20) can be passed through.

 Next, a method for producing composite particles using the above apparatus will be described.

(1) For example, powdery and granular raw materials such as Al and Ni are charged in a casing (4) in a premixed state at a predetermined mixing ratio. Further, an appropriate amount of small particles for grinding media having a diameter smaller than the gap width between the grinding pieces (9a) and the casing (4) is put into the casing (4).

(2) Cover the casing (4) and cover (7) with the lid (4
b) and (7a) are attached, the casing (4) is rotated at high speed, and the powdery and granular raw material is centrifugally applied to the inner peripheral surface (4a) of the casing.
To form a raw material layer and mix small particles for grinding media into the raw material layer.

(3) The milling pieces (9a) and scraping pieces (9b) that rotate relative to the casing (4) are made to act on the raw material layer, and as shown in FIG. 3, the pressure resistance of the milling pieces (9a), zirconia, etc. -The casing (4) is provided between the grinding piece (9a) and the small particles (6) for grinding medium by the cooperative action of the small particles (6) for grinding medium and the casing (4) having excellent wear resistance and heat resistance. ) And the small particles for grinding media (6) and between the small particles for grinding media (6), respectively, while the raw material layer (11) is thin, strong compressive force and shearing force are applied to the raw material. Is uniformly applied, and the raw materials are sufficiently mixed and dispersed by the cooperative action of the scraping piece (9b) and the small particles (6) for grinding media, and the particles are sufficiently complexed and the particle composition is uniform. To manufacture.

(4) After that, the driving device (5) is stopped, the cover (7) and the lids (7a), (4b) of the casing (4) are opened, and the composite particles are collected from the casing (4).

〔Example〕

Using an apparatus similar to that of the above example, Al having an average particle size of 30 μm
30 g, Ni 60 g with an average particle size of 7 μm, and 900 g of zirconia small particles for grinding media having a diameter of 1 mm were put into the casing, and a mixture of Al, Ni, and small particles for grinding media was put into the casing by high-speed rotation of the casing. It is pressed against the peripheral surface, and the milling piece and scraping piece are made to act on the raw material layer containing small particles for milling media, and
Composite particles with integrated Ni were made. The average particle diameter of the composite particles was 42 μm, and Ni was integrated on the surface of the Al particles, or composite particles in which Al and Ni were mixed were obtained.

(Another embodiment)

 Next, another embodiment will be described.

The raw materials can be appropriately selected in kind, combination, mixing ratio, particle size and the like. In particular, fine powders having a particle size of 1 to 100 μm and having a strong cohesive property, and various powder metallurgy raw materials are suitable targets.

In the combination of raw materials, the property relationship between the mother particle that becomes the core and the child particle that binds to the mother particle is as follows: (a) The particle diameter of the child particle is 1/2 or less of that of the mother particle, (b) Mother particle And the child particles have a softening point lower than that of the small particles for grinding media, and the child particles have a higher or lower softening point than the mother particles. (C) The mother particles and the child particles are granular and have a fibrous or flat shape. It is preferable that the above is not the case, and specifically, for example, there are combinations (a) to (h) below.

(A) Al and Li, which are raw materials for low-density and high-rigidity alloys (b) Cu, which is a raw material for sintered oil-impregnated bearings and filters
And Sn (c) Cu and W as raw materials for tungsten reinforced copper alloys and electrical contact materials (d) Fe and Cu and Fe as raw materials for alloys for sintering machine parts
Cu and Ni and Mo, or Fe and Mn and Cr (e) Fe and Ni and Cr, raw materials for sintered stainless steel (f) Cu and graphite powder, raw materials for metallic graphite brushes (g) Cermet (carbide WC which is a raw material of alloy) and Co (h) steel which is a raw material of Urad material (metal composite material),
One or more types of stainless steel, Al, Cu (base particles),
Al, Cu, Sn, Ni, Zn, Au, Ag, one or more species (child particles) The powder metallurgy raw material is, for example, refractory metal, porous metal, cemented carbide, cermet, composite alloy, SAP alloy, Raw materials for nuclear reactor materials, magnetic materials, difficult-to-cut materials, aircraft materials, etc.
It may be metal, metal carbide, metal oxide, ceramics, or any other material.

The small particles (6) for grinding media can be appropriately selected in terms of material, shape, input amount and the like. For example, zirconia, alumina, silicon nitride, silicon carbide, boron nitride, aluminum nitride, silica, glass, other ceramics,
Alternatively, it may be a metal such as chrome steel, or a natural material such as gold stone (diamond), gold sand, garnet, etc. Also, the shape may be a spherical shape, a substantially spherical shape, or a different diameter shape whose linear system changes depending on the direction, Various polyhedral shapes such as octahedron,
Other particles may be used, and the particle size is generally about 0.5 to 3 mm.

The type, component, application, etc. of the composite particles are not particularly limited.

The specific configuration of the device used in the present invention can be changed appropriately,
For example, the rotation axis of the casing (4) may be inclined or laid sideways, or the grinding pieces (9a) and scraping pieces (9b) may be urged by fluid pressure or springs within a range that does not contact the casing (4) side. , Stop rotation of the grinding pieces (9a) and scraping pieces (9b), change the shape, material, number of installation of the grinding pieces (9a), scraping pieces (9b), etc. Alternatively, an appropriate amount of cooled air, inert gas, or the like may be supplied into the casing (4). Also,
The scraping piece (9b) may be omitted when mixing and dispersion are unnecessary, such as when the raw materials are sufficiently premixed.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the structure shown in the attached drawings.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a conceptual view of a device used, FIG. 2 is a view taken along the line II-II of FIG. 1, and FIG. (4) …… Casing, (4a) …… Inner casing inner surface,
(6) …… Small particles for grinding media, (9a) …… Friction pieces, (9
b) …… Scraping piece, (11) …… raw material layer.

Claims (2)

(57) [Claims] 1. A casing (4) is rotated at a high speed, and a powdery granular material composed of a mixture of a plurality of materials is pressed against the inner peripheral surface (4a) of the casing (4) by a centrifugal force to form a raw material layer (1).
1) and forms a milling piece (9) that rotates relative to the casing (4).
When a) is applied to the raw material layer (11), the ground pieces (9
A method for producing composite particles, comprising: forming a composite particle in which the plurality of materials are integrated by compression and shearing according to a), the grinding particle having a diameter smaller than a gap width between the grinding piece (9a) and the casing (4). Small particles for media (6) are mixed in the raw material layer (11) to produce the milled pieces (9a) and small particles for milling media (6).
And a method for producing composite particles in which a compressive force and a shearing force are applied to the raw material by the cooperation of the casing (4). 2. A scraping piece (9b) rotating relative to the raw material layer (11) is acted to mix and disperse the raw material by the scraping piece (9b), and the small particles for grinding media. 2. The mixing and dispersion of raw materials is promoted by the action of (6).
A method for producing the composite particles described.