JP2001294909A - Alloy flake manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alloy flake manufacturing apparatus which is a crucible- type apparatus of manufacturing thin-strip alloy flakes used for, for example, a magnet, and can stably manufacture the thin-strip flakes having the high quality without any clogging at an outlet of a molten metal or any mixing of the slag. SOLUTION: In this alloy flake manufacturing apparatus raw alloy granules is melted to form the thin-strip flakes from the obtained molten metal. The apparatus comprises a crucible (3) for the raw alloy an arc electrode (4) melting the raw alloy by the arc discharge, and a cooling roller (5) for taking out the molten metal. A notch-like outlet (3A) having a notch which is fitted an outer circumferential edge of the cooling roller (5) is provided at the edge of the crucible (3), and a slag removing means (8) is provided in the upper part of the crucible (3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing alloy flakes, and more particularly, to a method of melting a granular raw material alloy and obtaining a molten metal from the obtained molten metal, for example, as a thin strip of R-Fe-B-based magnet material. The present invention relates to an apparatus for producing alloy flakes, which is capable of producing high-quality ribbon-shaped flakes without any obstruction at the outlet of the molten metal and without mixing of slag, in a more stable manner. .

[0002]

2. Description of the Related Art For example, a powder material of an R-Fe-B-based magnet is obtained by manufacturing a ribbon-like alloy flake from a granular raw material alloy and then crushing the alloy flake. JP-A-57-210934 discloses a technique relating to "high coercivity rare earth-transition metal magnet". And
In the above publication, a granular raw material alloy as a magnet raw material is melted in a cylindrical crucible wound with an induction heating coil, and the obtained molten metal is discharged from a nozzle (orifice) at the bottom of the crucible onto a cooling drum. In addition, there is described an apparatus for manufacturing alloy flakes that manufactures ribbon-shaped (ribbon-shaped) flakes by rotating a cooling drum.

[0003]

By the way, the apparatus for producing alloy flakes using a crucible having the above structure is suitable for a relatively small-scale production line because the apparatus can be downsized. As a result, the molten metal is rapidly cooled at the outlet of the nozzle, so that the nozzle is easily clogged, and it is difficult to quantitatively produce flakes. In addition, when the molten metal is discharged onto the cooling drum, there is a problem that slag attached to the outlet of the nozzle is easily entrained and the quality of the flakes is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to melt a granular raw material alloy and to produce a thin strip alloy as an R-Fe-B-based magnet material from the obtained molten metal. Disclosed is a crucible-type apparatus for producing flakes, which is an alloy flake production apparatus capable of producing a high-quality ribbon-shaped flake with no blockage at an outlet of a molten metal and with no slag mixed therein more stably. It is in.

[0005]

In order to solve the above-mentioned problems, an apparatus for manufacturing an alloy flake according to the present invention is an alloy flake for melting a granular raw material alloy and manufacturing a ribbon-like flake from the obtained molten metal. A crucible to which a granular raw material alloy is supplied; an arc electrode provided substantially above the crucible and melting the raw material alloy by arc discharge; and a horizontal crucible provided close to the crucible. A cooling roller for scraping the molten metal rotatably supported by a shaft, a part of the edge of the crucible is provided with a notch-shaped outlet opened toward the outside of the crucible, An outer peripheral edge of the cooling roller is fitted to the outlet, and slag removing means for removing slag in the crucible is provided above the crucible. .

[0006] In the above manufacturing apparatus, the supplied raw material alloy is melted into the molten metal by the arc discharge of the arc electrode, and the cooling roller is brought into contact with the molten metal at the outlet of the crucible, so that the outer periphery of the cooling roller is formed. Attaching molten metal and scraping. In this case, the structure in which the outer peripheral edge of the cooling roller is fitted to the outlet having a specific shape allows the molten metal that is always in a molten state to directly adhere to the outer peripheral portion of the cooling roller. In addition, the cooling roller cools the scraped-up molten metal to form a thin ribbon, and at the same time, flies by the centrifugal force of the cooling roller to form a ribbon-like flake. On the other hand, the removing means provided above the crucible removes the slag in the crucible by being operated.

In the above manufacturing apparatus, the crucible is preferably configured to be tiltable in a cooling roller and in a direction opposite to the cooling roller, and the tilting structure of the crucible is adjusted according to the liquid level of the molten metal. By adjusting the inclination of the crucible, the contact amount of the molten metal with the outer peripheral edge of the cooling roller at the outlet is kept constant. Further, the tilting structure of the crucible discharges the slag in the crucible by adjusting the tilt of the crucible according to the amount of slag generated on the liquid surface of the molten metal and functioning in cooperation with the above-described removing means.

In the manufacturing apparatus of each of the above aspects, the crucible is preferably a crucible made of copper or a copper alloy in order to prevent impurities from dissolving from the member.
Further, it is preferable that at least the outer peripheral portion of the cooling roller is made of a high melting point material.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an apparatus for producing alloy flakes according to the present invention will be described with reference to the drawings. FIG.
It is a side view with a partial fracture showing the structure of the principal part of the manufacturing device of the alloy flakes concerning the present invention. FIG. 2 is a plan view showing an assembly structure between the crucible and the cooling roller, and FIG. 3 is a longitudinal sectional view taken along a line III-III in FIG. FIG. 4 is a front view, a plan view, and a side view showing the shape of a base constituting an outlet of the crucible. Hereinafter, in the description of the embodiment, an apparatus for manufacturing alloy flakes is abbreviated as “manufacturing apparatus”.

The production apparatus of the present invention is an apparatus for producing alloy flakes for melting a granular raw material alloy and producing a ribbon-like flake from the obtained molten metal. As shown in FIG.
A crucible (3) to which a granular raw material alloy is supplied, an arc electrode (4) provided substantially above the crucible and melting the raw material alloy by arc discharge, and a horizontal shaft (3) provided close to the crucible 51) and a flat cooling roller (5) rotatably supported for melting the molten metal, and these members are disposed inside a casing (1) having a structure capable of maintaining a reduced pressure state.

The casing (1) can be depressurized by an exhaust device (not shown) provided separately, and can supply an inert gas such as Ar or He by a pipe (11). . That is, the casing (1)
Has an amorphous or near-crystalline grain size (for example,
In order to obtain a metal structure having an average crystal grain size of 50 to 300 nm), the pressure is reduced to a level slightly lower than the atmospheric pressure and an inert gas atmosphere is provided. Also, casing (1)
In order to suppress a rise in temperature due to heat of fusion, a channel for supplying a cooling medium such as water is provided in the wall as a cooling means.

As the raw material alloy to be supplied to the crucible (3), a material of an R-Fe-B-based magnet alloy whose composition is prepared in advance can be mentioned. The R component is one or more components selected from Pr, Nd, and Dy. The raw material alloy is
It is a granular material having a particle size of about 1 to 10 mm, which is produced by casting in advance by a separate large crucible and then pulverizing it.

The raw material alloy is continuously supplied to a crucible (3) in a casing (1) by a raw material supply mechanism (2). Specifically, the raw material supply mechanism (2)
Consists of a hopper (21) for storing granular material alloy, and a screw feeder (22) attached to the bottom of the hopper and for supplying the material alloy to the crucible (3) at a constant rate. A portion on the tip end side of the screw feeder (22) projecting into the casing (1) is configured to be able to be cooled by a cooling medium such as water.

The crucible (3) includes an arc electrode (4)
A crucible made of copper or a copper alloy is used in order to use it as a counter electrode. The crucible (3) made of such a material does not mix the Al component and the Si component into the molten metal unlike the conventional ceramic crucible, and can maintain the purity of the first raw material alloy in the molten metal.

As shown in FIGS. 2 and 3, the crucible (3) has, for example, an outer shape in a roughly bathtub shape.
A bowl-shaped storage space whose upper surface is opened in a substantially elliptical shape is provided. The size of the crucible (3) can be appropriately designed according to the scraping ability of the cooling roller (5). For example, the length of the long axis of the opening of the crucible (3) is about 30 to 300 mm.
The length of the short axis is about 20 to 280 mm, and the internal volume of the crucible (3) is about 0.002 to 7 liters.

The crucible (3) supplies a fixed amount of the molten metal to the cooling roller (5) without being affected by a change in the amount of the molten metal. In order to eliminate the cooling roller (5), the cooling roller (5) can be tilted in the opposite direction. Specifically, as shown in FIG. 1, the crucible (3) is supported above the base (32) via a support bar (33) pivotally attached to the front end side. The bottom of the crucible (3) on the rear end side can be moved up and down by a cylinder device (34) provided on the base (32). That is, the crucible (3)
Is configured such that the inclination angle in the front-rear direction can be adjusted by moving the cylinder device (34) forward and backward. In addition, crucible (3)
In the thick part, a flow path of a cooling medium such as water is provided as cooling means in order to prevent the melting of the crucible itself.

The arc electrode (4) is inserted from the upper part of the casing (1) and is usually arranged directly above the crucible (3). The arc electrode (4) is configured to perform arc discharge using the crucible (3) as the other electrode. Such an arc electrode (4) is variably attached to the casing (1) by, for example, a spherical bearing in order to adjust the state of discharge generated between the arc electrode (4) and the crucible (3). By the discharge of the arc electrode (4), in the crucible (3), the raw material alloy is melted at, for example, 1000 to 2800 ° C. The arc electrode (4) is housed in a jacket that can be cooled.

The cooling roller (5) is preferably made of a material that does not deteriorate due to heat from the viewpoint of facilitating maintenance management. In particular, at least the outer peripheral portion of the cooling roller (5) that comes into contact with the molten metal is It is preferable to use a high melting point material such as a high melting point metal or a high melting point compound whose melting point is higher than the temperature of the molten metal. Typically, the high melting point metal includes molybdenum steel, iron, vanadium, titanium, chromium steel, chromium stainless steel, niobium, tungsten and the like. In addition, as the high melting point compound, tungsten carbide,
Examples include carbides such as silicon carbide, nitrides such as boron nitride, and borides such as titanium boride.

The cooling roller (5) has, for example, a thickness of 5 to 5.
It is formed in a disk shape having a diameter of about 100 mm and a diameter of about 100 to 500 mm. The outer peripheral portion of the cooling roller (5) is formed into a relatively sharp curved surface due to the engagement relationship with the outlet (3A) described later. Note that the shape of the outer peripheral portion of the cooling roller (5) can be appropriately designed according to the type of the raw material alloy and the form of the flakes.

The cooling roller (5) is supported by a horizontal shaft (51) driven by an external motor (not shown), so that the cooling roller (5) is positioned from below with respect to the outlet (3A) of the crucible (3). It is configured to rotate upward.
Further, the shaft (51) of the cooling roller (5) has a double pipe structure for supplying a cooling medium such as water, and the cooling roller (5) has a hollow structure. Accordingly, the cooling roller (5) is maintained at a surface temperature of, for example, 100 to 700 ° C. by circulation of the cooling medium through the shaft (51).

In the manufacturing apparatus of the present invention, in order to stably take out the molten metal in the molten state, a notch-shaped outlet opening toward the outside of the crucible is provided at a part of the edge of the crucible (3). (3A) is provided and an outlet (3A)
Is fitted with the outer peripheral edge of the cooling roller (5). With such a structure, the cooling roller (5) can be brought into direct contact with the liquid level of the molten metal in the crucible (3).

Specifically, on the front end side of the crucible (3),
A base (31) as shown in FIGS. 2 and 3 is attached. As shown in FIG. 4, the base (31) is, for example, a vertically long block having a vertical groove (31c) having a substantially V-shaped horizontal cross section on the front surface. It is formed on an inclined surface that gradually increases from the side toward the front side.
The cross-sectional shape of the vertical groove (31c) can be set to various shapes such as a U-shape and a W-shape depending on the form of the flakes in addition to the V-shape.

The base (31) is a front end on the long axis of the opening of the crucible (3) (see FIG. 2), and has an upper end surface substantially coincident with the upper edge of the crucible (3). Now (see FIG. 3) it is fitted into the edge of the crucible (3). On the other hand, as shown in FIG. 3, the outer periphery of the cooling roller (5) is
Of the vertical groove (31c). In that case,
As shown in FIG. 2, the outer peripheral edge of the cooling roller (5) is set at a state slightly separated from the deep end of the vertical groove (31c).

Further, as shown in FIG. 1, in the manufacturing apparatus of the present invention, a flake housing () for housing flakes formed into a thin strip by the cooling roller (5) is provided at the bottom of the casing (1). A guide plate (6) is provided on the outer peripheral side of the cooling roller (5) for receiving the flakes blown to the outer peripheral side by the cooling roller and dropping the flakes into the flake storage portion (7). Be placed.
The guide plate (6) is provided with a flow path for a cooling medium such as water as a cooling means in order to suppress the temperature rise of the guide plate and increase the cooling efficiency of the flakes.

Incidentally, the alloy applied to the above-mentioned magnet material contains a trace amount of impurities that could not be removed in the process of refining the granular alloy material, and the casing of the apparatus shown in FIG. A small amount of oxygen remains inside 1). As a result, when the molten metal is continuously formed from the alloy raw material for a long time, the slag floats on the liquid surface of the molten metal in the crucible (3).

Therefore, in the manufacturing apparatus of the present invention, in order to maintain the quality of the molten metal in the crucible (3), a slag removing means (8) for removing slag in the crucible is provided above the crucible (3). ) Is provided. As the slag removing means (8) having the simplest structure, there is a slag removing rod as shown in FIG. The tip of such a slag removing rod is formed of the above-mentioned high melting point metal or ceramic similar to the cooling roller (5) and is configured to be replaceable in consideration of wear due to contact with the molten metal. The above slag removal rod is
For example, it is attached to the casing (1) in such a manner that its tip can be brought into contact with the liquid surface of the crucible (3) and the direction of which can be changed by a spherical bearing.

Further, when a large amount of slag accumulates on the liquid surface of the molten metal, the slag is discharged together with a part of the molten metal. Therefore, the slag removing means (8) is used in combination with the cooling roller (5) tilting structure described above. It can also function. And, at the bottom of the casing (1) below the crucible (3), a slag storage part (9) for storing the discharged slag is provided.

In the manufacturing apparatus of the present invention, alloy flakes are manufactured by the following functions. That is, the granular raw material alloy contained in the hopper (21) of the raw material supply mechanism (2) is continuously supplied to the crucible (3) by the screw feeder (22). Along with the supply of the raw material alloy to the crucible (3), a voltage is applied to the arc electrode (4) and the crucible (3), and the raw material alloy in the crucible (3) is melted by the arc discharge of the arc electrode (4). Melts.
Then, while the molten metal obtained by melting is stored in the crucible (3), the cooling roller (5) is driven to rotate.

In the manufacturing apparatus of the present invention, the outlet (3
In A), the cooling roller (5) is brought into contact with the molten metal of the crucible (3) to scrape up the molten metal adhering to the outer peripheral portion of the cooling roller (5). At this time, the structure in which the outer peripheral edge of the cooling roller (5) fits into the outlet (3A) of the crucible (3) formed in a specific shape is used to transfer the molten metal that is always in a molten state to the outer peripheral portion of the cooling roller (5). Directly adhere to Therefore, it is possible to always scrape out a fixed amount of the molten metal in a state in which impurities such as slag are extremely small according to the rotation speed of the cooling roller (5).

The cooling roller (5) cools the molten metal adhering to the outer peripheral portion as described above almost simultaneously with the adhering, and forms the molten metal into a thin strip shape. Further, the cooling roller (5) causes the scraped-up ribbon (solidified material of the molten metal) to fly above the cooling roller (5) or to the side opposite to the crucible (3) by the centrifugal force of the cooling roller. As a result, the ribbon is formed into a hard and segmented ribbon flake by the flight from the cooling roller (5) and the collision with the guide plate (6). Further, the guide plate (6) causes the flakes obtained by the collision to drop toward the flake storage section (7).

On the other hand, when the alloy flakes are continuously produced for a long time by the above-described operation, as described above, slag gradually accumulates in the molten metal of the crucible (3), though slightly. I do. In that case, the slag removing rod as slag removing means (8) provided above the crucible (3) is operated to bring the slag into contact with the liquid surface of the molten metal to scrape and collect the slag. The slag in () can be removed by adhering to the tip of the slag removal rod. Therefore, in the manufacturing apparatus of the present invention, the molten metal in the crucible (3) can be kept in a clean state even in the continuous operation.

As described above, in the manufacturing apparatus of the present invention, the cooling roller (5) is directly attached to the molten metal in a molten state to scrape out the molten metal in the crucible (3). There is no blockage at the outlet (3A), and the molten metal can be always kept in a clean state by the slag removing means (8), so that a high-quality ribbon-shaped flake without slag can be stably manufactured. Moreover, as described above, the raw material alloy is supplied by the screw feeder (22) capable of cooling the front end portion, and a crucible made of copper or a copper alloy is used as the crucible (3). The resulting flakes do not contain impurities such as Si components.

Further, in the manufacturing apparatus of the present invention, the tilting structure of the crucible (3) allows the inclination of the crucible (3), that is, the height of the outlet (3A) of the crucible (3) to be adjusted by the liquid of the molten metal. By adjusting according to the surface, the outlet (3
In A), the contact amount of the molten metal to the outer peripheral edge of the cooling roller (5) can be always kept constant, so that the amount of the molten metal attached to the outer peripheral portion of the cooling roller (5) can be made more uniform. As a result, the production apparatus of the present invention can quantitatively produce more uniform alloy flakes without being affected by the fluctuation of the molten metal in the crucible (3).

In addition, the tilting structure of the crucible (3) is such that the inclination of the crucible (3) is adjusted according to the amount of slag generated on the liquid surface of the molten metal in the crucible (3), that is, the amount of slag is large. When the crucible (3) accumulates in the slag, the crucible (3) is tilted to the side opposite to the cooling roller (5), so that the slag together with a part of the molten metal is stored in the slag storage section (9) at the bottom of the casing (1).
Can be discharged to Further, the slag in the crucible (3) can be more easily discharged by cooperatively using the slag removing means (8). As a result, in the manufacturing apparatus of the present invention, higher quality alloy flakes can be stably manufactured without being affected by the fluctuation of the molten metal in the crucible (3).

[0035]

According to the apparatus for manufacturing alloy flakes of the present invention, the molten metal in the molten state is directly applied to the outer peripheral portion of the cooling roller by the specific structure in which the outer peripheral edge of the cooling roller is fitted to the outlet of the crucible. Since it is adhered and scraped out of the crucible, there is no obstruction at the crucible outlet, and the slag removing means can always keep the molten metal in a clean state, thus stabilizing high-quality thin flakes without slag mixing. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a partially broken side view showing a structure of a main part of an apparatus for manufacturing an alloy flake according to the present invention.

FIG. 2 is a plan view showing a structure in which a crucible and a cooling roller are combined.

FIG. 3 is a longitudinal sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a front view, a plan view, and a side view showing shapes of a base constituting an outlet of a crucible.

[Explanation of symbols]

 1: Casing 2: Material supply mechanism 3: Crucible 31: Cap 31c: Vertical groove 3A: Outflow port 4: Arc electrode 5: Cooling roller 51: Shaft 6: Guide plate 7: Flake accommodating section 8: Slag removing means 9: Slag Accommodation

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01F 1/06 H01F 1/06 A (72) Inventor Hirotaka Mizuguchi 1-4-4 Meiji Shinkai Kaisha Toda Kogyo Co., Ltd., Otake City, Hiroshima Prefecture Inside the Otake Creative Center (72) Inventor Masaaki Hamano 1-4 Meiji Shinkai, Otake City, Hiroshima Prefecture Toda Kogyo Co., Ltd. Inside the Otake Creative Center (72) Inventor Kunio Ikemoto 1-4 Meiji Shinkai, Otake City, Hiroshima Prefecture Toda Kogyo Co., Ltd. F-term in Otake Creative Center (reference) 4E004 DB02 TA03 TB04 4K017 AA04 BA06 BA08 BB06 BB12 CA03 DA04 EC02 EK02 5E040 AA04 AA19 CA01 HB17

Claims (5)

[Claims] An apparatus for manufacturing an alloy flake for melting a granular material alloy and producing a ribbon-like flake from the obtained molten metal, wherein a crucible (3) supplied with the granular material alloy is provided.
An arc electrode (4) provided substantially above the crucible and melting the raw material alloy by arc discharge; and a melt scraping provided near the crucible and rotatably supported by a horizontal shaft (51). And a notch-shaped outlet (3A) opened toward the outside of the crucible at a part of the edge of the crucible (3). Is characterized in that the outer peripheral edge of the cooling roller (5) is fitted, and a slag removing means (8) for removing slag in the crucible is provided above the crucible (3). An apparatus for producing alloy flakes. 2. The apparatus for producing alloy flakes according to claim 1, wherein the crucible (3) is configured to be tiltable toward the cooling roller (5) and the opposite direction. 3. The apparatus for producing alloy flakes according to claim 1, wherein the crucible is a crucible made of copper or a copper alloy. 4. The apparatus for producing alloy flakes according to claim 1, wherein at least the outer periphery of the cooling roller (5) is made of a high melting point material. 5. The method according to claim 1, wherein the raw material alloy is an alloy for an R—Fe—B magnet (where the R component is one or two or more components selected from Pr, Nd, and Dy). An apparatus for producing an alloy flake according to any one of the above.