WO2010010627A1 - Dispositif et procédé de fabrication de poudre fine utilisant un creuset rotatif - Google Patents
Dispositif et procédé de fabrication de poudre fine utilisant un creuset rotatif Download PDFInfo
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- WO2010010627A1 WO2010010627A1 PCT/JP2008/063371 JP2008063371W WO2010010627A1 WO 2010010627 A1 WO2010010627 A1 WO 2010010627A1 JP 2008063371 W JP2008063371 W JP 2008063371W WO 2010010627 A1 WO2010010627 A1 WO 2010010627A1
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- Prior art keywords
- crucible
- fine powder
- rotating
- powder molding
- molding method
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/10—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying using centrifugal force
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2201/00—Treatment under specific atmosphere
- B22F2201/10—Inert gases
Definitions
- the present invention relates to a metal powder, metal powder, metal powder for thermal metallurgy, magnetic material, spherical metal powder for thermal spraying, metal powder for conductive paste, solder ball, and regenerator material for magnetic refrigerator, etc.
- the present invention relates to a method for producing spherical fine particles applicable to a wide range of inorganic and organic substances used in foods, pharmaceuticals, chemical industries, and the like, and a centrifugal spray device thereof.
- centrifugal spraying methods As a method for forming a metal or alloy into a spherical powder, various centrifugal spraying methods are known in addition to a rotating consumable electrode method, a droplet dropping spraying method, a gas atomizing method, a water atomizing method, and the like.
- the powder particle size in these methods is generally widely distributed over several ⁇ m to several 100 ⁇ m, and there are restrictions on the control of the particle size produced, and there are problems in productivity, There are many challenges.
- the centrifugal spray method of the present invention can obtain spherical fine powder having a particle size of 50 ⁇ m or less and a narrow distribution width in addition to good controllability of operation parameters.
- the centrifugal spraying method in the prior art is, for example, a disk with a flat surface as a rotating body, a disk with irregularities (Patent Documents 1 and 2), or a dish with a dent in the upper part of a disk ( Patent Document 4), on the other hand, has been proposed in which various processes are added in consideration of pouring and scattering of the target raw material, using a circular plate as a basic shape, such as an umbrella having an upper slope.
- JP 2006-2176 A JP 2002-317212 A Japanese Patent No. 3511082 Japanese Patent Laid-Open No. 10-85583 Japanese Patent No. 3270713 Japanese Patent Laid-Open No. 05-171228
- the present invention has been made in view of the above-described circumstances, and a method for producing a powder capable of producing a powder composed of fine particles having a narrow particle size distribution and a uniform particle size with good mass productivity. And it aims at providing the device.
- the raw material molten metal is supplied to the bottom surface in the vicinity of the center axis center of the rotating container having a heated cylindrical crucible shape housed in the chamber, the centrifugal force is sufficiently applied to the molten metal, and the molten metal is pressed against the inner wall surface of the crucible, It is spattered from the crucible opening by centrifugal force so as to balance the amount of molten metal that is continuously supplied, and is sprayed and sprayed into an atmospheric gas such as argon, helium, nitrogen, air in the chamber, and so on. Produce powder.
- an atmospheric gas such as argon, helium, nitrogen, air in the chamber, and so on.
- the present invention also provides a melting device for melting a target material in a chamber, a crucible for receiving the molten material from the melting device, a driving device for rotating the crucible at a high speed along a rotation center axis, and the melting
- a powder production apparatus comprising a pouring nozzle for pouring molten material from the apparatus onto the bottom surface of the crucible, and a rotation equipped with the chamber containing fine powder obtained by centrifugally spraying the molten material from the open end of the crucible. This is a fine powder molding apparatus using a crucible.
- the molten metal droplets scattered from the opening end of the upper end surface of the crucible have a uniform velocity distribution, it is possible to produce a powder composed of fine particles having a narrow particle size distribution width and uniform particle size. It is.
- the molten metal is temporarily stored in a tundish and then sprayed while the molten metal flow rate from the nozzle is controlled at a constant level. Therefore, the molten material is added in the melting furnace while checking the amount of molten tundish. Since it can be dissolved, powder can be produced continuously, and high productivity is ensured.
- the produced fine powder is spherical and has a uniform diameter, and has a wide range of uses as a solder ball, a thermal spray material, or a metal injection-generating material.
- FIG. 1 is an overall view of a powder production apparatus as an embodiment of the present invention. It is the figure which showed the behavior of the structure around a rotation crucible, and the molten metal poured. It is a figure which shows the crucible periphery provided with the heating body which heats the inner wall of a rotation crucible in detail. It is a figure which shows the heating body which heats a rotation crucible.
- FIG. 1 is an overall view of the apparatus
- FIG. 2 shows the structure around the rotating crucible and the behavior of the molten metal to be poured.
- FIG. 3 is a view showing in detail the periphery of the crucible provided with a heating body for heating the inner wall of the rotating crucible
- FIG. 4 is a view showing a heating body for heating the rotating crucible.
- the centrifugal spraying apparatus includes a melting furnace 2 inside the chamber 1, loads a raw material to be melted from the raw material additional apparatus 3 into the melting furnace 2, and heats to form a molten metal A.
- the formed molten metal A is transferred to a holding furnace (tundish) 4 and poured from the nozzle 5 onto the bottom surface of the cylindrical crucible 10.
- the crucible 10 is preferably provided with a heat insulating material 12 around it, and more preferably housed in a heat-resistant metal crucible receiver 13 and can be rotated at high speed by a rotating shaft from the outside of the container.
- the heat-resistant metal crucible receiver 13 is preferably provided with fins 14 for cooling.
- the holding furnace (tundish) 4 and the nozzle 5 are provided with high-frequency induction heating coils 15 and 16 for keeping the molten metal warm. In addition, you may use the electric heating body 8.
- FIG. When operating for a long time, it is desirable to cool the chamber with water. The chamber is filled with a gas flow, and the generated particles are cooled. In order to enhance the cooling effect, the pressure can usually be increased to 10 atmospheres.
- An induction coil 16 is arranged on the outer surface of the pouring nozzle 5, and a heat generating sleeve 17 is installed on the inner and outer surfaces of the induction coil and on the lower part of the nozzle, and the inner surface and the bottom surface of the pouring nozzle and the crucible are irradiated by radiation from the sleeve.
- the exothermic sleeve is, for example, a refractory cylinder covered with a graphite cylinder, and this graphite portion is an induced current or resistance overheated.
- the molten metal A is poured into the vicinity of the center of the crucible 10 that rotates at high speed, and the molten metal A is pressed against the inner wall of the crucible by centrifugal force, and the liquid film state is ensured to be scattered at a high speed from the crucible opening to constitute the atmosphere.
- the powder B is produced by atomization by rapid collision with a gas such as He gas, Ar gas, or N 2 gas, and rapidly solidifying.
- the produced coagulated powder B is continuously collected in a product container 6 provided at the lower part of the container 1.
- it is desirable that the crucible opening is arranged at right angles to the vertical line in order to scatter the molten metal from the crucible opening.
- the crucible has a saddle-shaped or cylindrical side wall, and the side wall may be wide or wide within ⁇ 10 degrees with respect to the vertical.
- the crucible can be made of heat-resistant calcium, zirconia, high melting point molybdenum, or the like.
- the greatest merit of the powder production according to the present invention is that the molten metal A is formed in a liquid film shape on the inner wall of the crucible 10 by centrifugal force, and the rotating disk which is the greatest point in the prior art is not used. It is not necessary to consider the disc material. That is, in the prior art, securing the wettability with the target metal was a big problem in selecting the disk material, whereas in the present invention, the crucible material in a molten state with the target metal is simply used for the above reason. Only the viewpoints of heat resistance and reactivity need be considered.
- the rotating crucible 10 is disposed on the outside thereof. It is possible to make the crucible receiver 13 made of heat-resistant metal bear mechanical strength, and the characteristics required for the crucible 10 are greatly relieved from this viewpoint.
- the upper opening diameter (D) and its depth (H) are more preferably 10 to 0.5 and 5 to 0.5 in terms of D / H. This is because uniform spraying cannot be obtained outside this range.
- the melt raw material melted and adjusted in the high frequency induction furnace 2 or the like is set at the bottom of the tundish through a holding furnace held at a high temperature using means such as high frequency induction or the tundish (intermediate vessel) 4.
- hot water is poured onto the bottom surface at the center of the crucible 10 rotating at a high speed at a predetermined hot water supply speed.
- the pouring position may be gradually changed / moved from the center of the crucible toward the radial direction at a predetermined speed in order to prevent the pouring part from being locally melted.
- the distance that can be moved is within about 1/2 of the crucible radius. It is preferable to fit in.
- the molten metal poured on the bottom of the crucible moves to the crucible side wall surface by centrifugal force, and then the molten metal in the centrifugal casting gradually increases the melt thickness at the crucible side wall surface by the molten metal poured continuously. Similar to the above, the crucible side wall surface rises in a liquid film state while receiving a strong centrifugal force. As soon as the melt in the liquid film state reaches the upper end of the opening of the crucible 10, it is scattered at high speed in the atmosphere by the energy accumulated by being released from the centrifugal force, and is atomized along with the sudden frictional collision with the atmospheric gas. To do.
- the centrifugal force is sufficiently applied to the melt liquid film existing on the side wall surface of the crucible, and the slip between the disk and the liquid film as in the conventional centrifugal spraying by the disk rotation may exist.
- it is not affected by the material and shape of the rotating disk, which is a problem from the viewpoint of wettability with the liquid film in the prior art.
- the scattering velocity distribution at the time of scattering from the crucible opening end is a velocity distribution in a very narrow range, and as a result
- the powder produced by the method and apparatus of the present invention has a very uniform size distribution, and the shape of the powder is scattered in the form of droplets, and solidification is completed, so that the degree of circularity is extremely high. Is obtained.
- Q / r 2 n is defined from (/ min), crucible radius r (cm), and rotational speed n (min ⁇ 1 ).
- the operating parameters can be changed from 2000 rpm to 50000 rpm in accordance with the optimization of the crucible diameter while corresponding to the desired powder size and production speed. For example, if a crucible with a radius of 2.5 cm is used for pure copper and molten metal is poured at a rate of 10 kg per minute while giving 2000 revolutions per minute, the density of molten pure copper is 7.8 g / cm 3 , Q / The value of r 2 n is 0.10 (cm).
- the value of Q / r 2 n is 1.0 In the case of ⁇ 10 ⁇ 6 (cm), and the same hot water supply speed of 0.1 kg / min and a crucible with a radius of 16 cm and a rotational speed of 50000 min- 1 , the value of Q / r 2 n is 1.0 ⁇ 10 ⁇ 6 ( cm).
- the relationship between the hot water supply speed Q (cc / min) for producing fine metal powder while controlling the liquid film thickness, the crucible radius r (cm), and the crucible rotation speed n (min- 1 ) is Experience has shown that in order to generate particles having a diameter of 50 ⁇ m or less, it is sufficient to control to the range of the following formula.
- the method for heating the crucible is not limited to high frequency induction heating. That is, when heating at a relatively low temperature is sufficient, radiation heating with an infrared lamp is possible.
- a rotating shaft is placed on the outer periphery of the crucible or at the bottom of the crucible bottom.
- a permanent magnet separated and fixed can be arranged, and heating by an eddy current generated along with the rotation of the crucible can be performed by electromagnetic induction with the permanent magnet.
- FIG. 3 shows an example of a graphite heating body.
- Example 1 In the argon gas atmosphere container of about 1 atm, the following rotating body was installed for the purpose of rotating spray. First, a carbon crucible having an inner diameter of 85 mm and a depth of 65 mm was used as a rotating crucible. On the outer periphery of the crucible, a heat insulating structure was formed with porous ceramics mainly composed of zirconia having a thickness of 8 mm. These rotating bodies are housed inside a crucible receiver formed of Inconel 600.
- fins having a blade thickness of 1.5 mm and a depth of 6 mm are provided at a pitch of 8 mm in the crucible height direction for the purpose of cooling.
- the thickness of the fin becomes thinner as it goes away from the outer cylinder surface of the crucible for weight reduction.
- Example 2 For pure copper, we attempted further refinement at a casting rate of 1.0 kg / min for a nozzle diameter of 1.0 mm ⁇ for a diameter of 200 mm ⁇ crucible and a crucible rotation speed of 35000 min- 1 . Compared with Example 1, since the crucible diameter is large, the centrifugal force received by the liquid film is also large, and the obtained particle size distribution has an average particle size less than half that of Example 1.
- Example 3 Using an alumina crucible, a powder production test was conducted on 95.75% Sn, 3.5% Ag, and 0.75% Cu alloy, which are lead-free solders. As a result of testing under the test conditions as shown in Table 1, a powder having an average diameter of 10 ⁇ m could be produced.
- Example 4 Using an alumina crucible, a powder production test was conducted on 30% Ag, 38% Cu, and 32% Zn alloy used for silver brazing. As a result of testing under the test conditions shown in Table 1, powder having an average diameter of 32 ⁇ m could be produced.
- Example 5 Using stainless steel (SUS316L), a large diameter crucible was used for the purpose of producing fine powder with high productivity.
- the pouring nozzle diameter used was 1.5 mm ⁇ , and the nozzle heating, crucible heating, and the structure around the crucible were similar to the series of examples corresponding to the crucible size.
- the average particle size was 5.2 ⁇ m
- the cumulative 10% was 2.1 ⁇ m or less
- the cumulative 50% was 4.2 ⁇ m or less
- the cumulative 90% was 7.8 ⁇ m or less.
- Comparative Example 1 A spray test was conducted on Sn-Ag-Cu solder using a flat disk disc (diameter 120 mm ⁇ manufactured by SUS304, thickness 23 mm) as found in the prior art instead of the crucible. Note that all the structures around the rotating crucible used in Examples 1 to 5 were removed, and in order to avoid the solidification of the molten metal on the disk surface, a magnetic pole in the circumferential direction with the same diameter as the disk was placed on the back surface side of the disk. A 6-pole permanent magnet with alternating changes was placed, and the disk surface was heated to 430 ° C. while adjusting the distance from the disk. The permanent magnet is covered with a thin heat insulating sheet and is fixed separately from the rotating shaft. The test conditions are shown in Table 1. Although the produced powder had an average particle size of 85 ⁇ m, it had a very wide particle size distribution from a size of several microns to a maximum of 320 microns.
- Comparative Example 2 For the disk used in Comparative Example 1, the surface is processed into a spherical shape with a radius of 600 mm and a constant radius, and the outermost peripheral part is raised by about 3 mm with respect to the center of the flat plate. A device that can be applied to the film was made. The test conditions were exactly the same as in Comparative Example 1, but the average particle size was 56 ⁇ m, and there were no giant particles as seen in Comparative Example 1, and a powder with a relatively narrow particle size distribution was obtained. This seems to be a result of comparatively sufficient application of centrifugal force to the molten metal relative to Comparative Example 1.
- the average particle size is 74 ⁇ m
- the cumulative 10% weight is 8 ⁇ m or less
- the cumulative 50% weight is 68 ⁇ m or less
- the cumulative 90% weight is 145 ⁇ m or less.
- Table 1 The results of the above examples are shown in Table 1.
- the heating means can be energized resistance heating in addition to high-frequency induction heating. Furthermore, in general, there is a concern about melting and wear of the crucible due to molten metal in the pouring part, so that the pouring position is gradually moved in the radial direction of the crucible when there is a margin in the crucible size.
- a mechanism may be provided.
- the electromagnetic flow control method is incorporated in the pouring flow control, but a stopper method immersed in a holding furnace (tundish) may be adopted.
- Solder balls Ultra-compact LSI parts such as BGA (Ball Grid Array) and CSP (Chip Size Package) use solder balls as contact materials in mobile phones, digital home appliances, etc., but the current ball size is 50-100 ⁇ m. The diameter is expected to be reduced to 5 to 10 ⁇ m in the future in response to LSI miniaturization.
- the fine particles obtained by the method of the present invention have high size uniformity and roundness, and these problems can be solved at once. Sn-Ag, Sn-Ag-Cu, Sn-Ag-Cu-Bi , Sn-Bi series, Sn-Cu series, Sn-Zn series, etc. can be manufactured.
- MIM metal injection molding material
- metal powder injection molding instead of conventional press-molding powder metallurgy
- injection molding is a metal powder injection molding (injection molding) in a state of being wrapped in a binder.
- Sintered bodies manufactured by Metal Injection Molding hereinafter referred to as MIM
- MIM Metal Injection Molding
- MIM is preferably spherical and dense fine powder with high packing density, and spherical fine powder is more likely to flow. From the viewpoint of reducing product defects, Fine powder is indispensable.
- the production of the powder according to the present invention can provide a powder suitable for such use.
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Abstract
L’invention concerne un procédé et un dispositif de fabrication de poudre de fines particules ayant une largeur de distribution de petit diamètre de particules, c’est-à-dire des diamètres de particules similaires, avec une productivité élevée. Une matière première fondue A est introduite dans une surface inférieure à proximité du centre de l’axe de rotation d’un récipient rotatif ayant un creuset cylindrique chauffé (10) disposé dans une chambre. La matière première fondue est soumise à une force centrifuge de façon à être poussée contre la paroi interne du creuset et injectée pour voler dans la chambre contenant un gaz atmosphérique tel que l’argon, l’hélium, l’azote et l’air, par une force centrifuge, depuis une ouverture du creuset, de façon à fabriquer une poudre ultrafine B ayant des tailles de particules similaires.
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108971506A (zh) * | 2018-07-02 | 2018-12-11 | 王尚木 | 一种批量化低成本生产贵金属微小球珠的装置及方法 |
CN110539001A (zh) * | 2019-08-29 | 2019-12-06 | 北京康普锡威科技有限公司 | 连接杆、自冷却离心转盘雾化制粉装置及雾化制粉方法 |
CN113399674A (zh) * | 2021-06-18 | 2021-09-17 | 唐山市嘉恒实业有限公司 | 一种颗粒更均匀的金属粒化装置和制备方法 |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2007332406A (ja) * | 2006-06-13 | 2007-12-27 | Sanki Dengyo Kk | 回転ルツボを使用した微粉末成形方法とその装置 |
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- 2008-07-25 WO PCT/JP2008/063371 patent/WO2010010627A1/fr active Application Filing
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JP2007332406A (ja) * | 2006-06-13 | 2007-12-27 | Sanki Dengyo Kk | 回転ルツボを使用した微粉末成形方法とその装置 |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN108971506A (zh) * | 2018-07-02 | 2018-12-11 | 王尚木 | 一种批量化低成本生产贵金属微小球珠的装置及方法 |
CN110539001A (zh) * | 2019-08-29 | 2019-12-06 | 北京康普锡威科技有限公司 | 连接杆、自冷却离心转盘雾化制粉装置及雾化制粉方法 |
CN110539001B (zh) * | 2019-08-29 | 2022-12-30 | 有研增材技术有限公司 | 连接杆、自冷却离心转盘雾化制粉装置及雾化制粉方法 |
CN113399674A (zh) * | 2021-06-18 | 2021-09-17 | 唐山市嘉恒实业有限公司 | 一种颗粒更均匀的金属粒化装置和制备方法 |
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