JPH06315743A - Manufacture of sendust foil belt - Google Patents

Abstract

PURPOSE:To provide a manufacturing method for a 'sendust(R)' foil belt having fine and uniform crystal structure and excellent magnetizing characteristics. CONSTITUTION:A metallic alloy having a structure of 84 to 86wt.% Fe, 9.4 to 9.8wt.% Si and 5.2 to 5.7wt.% Al is charged in a crucible 1 and melted to obtain a melted metal alloy 2. The melted metal alloy 2 is continuously extruded from a nozzle 3 and poured on the inside circumference 4a of a conical turning cooling body 4 which is turned at a constant speed. Then, a continuous 'sendust(R)' foil belt 6 is obtained from the lower end opening party of turning cooling body 4. The opening angle of turning cooling body 4 is 45 to 75 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for directly and continuously producing a sendust foil strip having excellent magnetic properties from a molten metal.

[0002]

2. Description of the Related Art Since a sendust alloy material is used as a magnetic material, it is required to have a fine and uniform structure in order to improve the magnetization characteristics. In addition, since a brittle product is produced when manufactured by a normal casting method, manufacture by a rapid solidification method has been studied in order to obtain a product having high magnetization characteristics and toughness.
As a rapid solidification method, a single roll method, a twin roll method, and a centrifugal quench method are known.

In the one-roll method, molten metal is poured into a rotating single rotor and rapidly cooled, and the cooled metal is continuously fed from the rotor due to the centrifugal force of the rotor and the difference in the adhesive force between the metal and the rotor. The metal foil strip is manufactured by peeling. In this case, the cooling rate is determined by the time during which the molten metal contacts the rotor. Regarding the surface of the foil strip to be produced, a dense and smooth surface can be obtained by adjusting the roughness of the rotor surface on the surface in contact with the rotor (hereinafter referred to as the roll solidification surface). However, the surface that does not come into contact with the rotor (hereinafter referred to as the free solidification surface) has its surface roughness determined by the viscosity of the molten metal and the surface tension. Therefore, the one-roll method can obtain a relatively smooth surface when producing a foil strip of an alloy having a large viscosity or surface tension such as an amorphous alloy, but like the Sendust alloy, When manufacturing a foil strip of an alloy having a relatively low viscosity, there is a drawback that the surface of the product becomes rough.

Further, in the twin roll method, the molten metal is sandwiched by two rolls adjacent to each other and cooled, so that the cooling rate can be increased and a foil strip having a relatively smooth surface can be obtained. it can. However, in this method, when a thin foil strip is manufactured, for example, a gap between rolls is set to 50 μm.
It was necessary to adjust to m or less, which was a very difficult manufacturing method in practice. Therefore, at present, mass production by the twin roll method is hardly performed.

On the other hand, it has been attempted experimentally to manufacture a sendust foil strip by a centrifugal quenching method which has been conventionally used for producing an amorphous foil strip.

FIG. 7 schematically shows an example of an apparatus for carrying out the conventional centrifugal quenching method. In the figure, 1 is a crucible supported in the vertical direction,
A metal material is charged from the upper end and melted. Reference numeral 3 denotes a nozzle for pouring a molten metal, which is formed at the lower end of the crucible 1 and is bent at an angle of about 90 ° with respect to the direction of gravity and opens. Reference numeral 4 is a dish-shaped rotary cooling body that is rotatably supported by a rotary shaft 9 and has an open top.
The tip of the nozzle 3 is arranged close to one location of the inner peripheral surface 4a of the rotary cooling body 4. The inner peripheral surface 4a of the rotary cooling body 4 has a conical shape that spreads upward, and the release angle θ that is the apex angle thereof is generally 20 to 60 °.
It is said that.

Therefore, in the centrifugal quenching method using the apparatus shown in FIG. 7, the molten metal melted in the crucible 1 is continuously passed through the nozzle 3 to the inner peripheral portion 4a of the rotary cooling body 4 rotating at a constant speed. Foil strip 6 obtained by pouring and rapidly solidifying
Are continuously taken out from the rotary cooling body 4 by centrifugal force.

According to this centrifugal quenching method, the molten metal is pressed against the inner peripheral surface 4a of the rotary cooling body 4 by the centrifugal force to cool it, so that the contact time with the cooling body 4 becomes longer and compared with the one-roll method. The cooling rate can be increased to obtain a finer and more uniform structure. However, the apparatus shown in FIG. 7 has a problem that the continuously manufactured foil strip 6 is easily entangled with the nozzle 3 and is not suitable for mass production.

Therefore, as an improvement of the centrifugal quenching method, US
P3,881,540 discloses a method of pouring a molten metal on the inner peripheral surface of a rotary cooling body opened at a constant opening angle in the lateral direction and discharging a continuous foil strip sideways. There is.

However, the above USP 3,881,5
Also in the method of No. 40, since the foil strip is continuously discharged laterally by utilizing the centrifugal force of the rotary cooling body, there is a problem that the foil strip is entangled inside the rotary cooling body, which is not suitable for mass production. There wasn't.

[0011]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to continuously produce a sendust foil strip having a high magnetizing property with high productivity by utilizing the magnitude of the cooling rate which is a characteristic of the centrifugal quenching method. To provide a method.

[0012]

In order to achieve the above object, the present invention provides Fe: 84 to 86% by weight, Si: 9.4.
-9.8 wt%, Al: 5.2-5.7 wt%, a metal material having an alloy composition is melted, and the molten metal is continuously poured onto the surface of the rotary cooling body to rapidly solidify the sendust foil. In the method for manufacturing a band, as the rotary cooling body, a center of rotation is supported in the vertical direction and has a conical inner peripheral surface whose lower part is widened and opened, and at the apex angle of the cone of this inner peripheral surface. It is characterized in that a certain opening angle is 45 to 75 ° and the molten metal is poured onto the inner peripheral surface of the rotary cooling body.

[0013]

In the present invention, the molten metal poured on the inner peripheral surface of the rotating cooling body is centrifugally pressed against the inner peripheral surface of the cooling body to be cooled. Therefore, the contact time with the cooling body becomes long and the cooling rate becomes high, so that a sendust alloy foil strip having a fine and uniform structure can be obtained.

Further, since the free solidification surface is on the inside, this surface is pressed by centrifugal force to form a dense structure, and a smooth surface can be obtained. Further, since the grain boundaries are less likely to be biased, there is no obstacle wall when magnetized, and it is easy to magnetize in one direction. Therefore, it is possible to obtain a desired magnetic permeability as a soft magnetic material.

Further, the rotary cooling body used in the present invention has a conical shape in which the lower part widens and is opened as a whole, and the opening angle is limited to 45 to 75 °. When the molten metal is poured into the inner peripheral surface of the rotary cooling body having such a shape from above and the foil strip is taken out from the lower end, the centrifugal strip and the action of gravity make it possible to discharge the foil strip satisfactorily. It is possible to continuously manufacture a uniform foil strip of.

[0016]

FIG. 1 shows an embodiment of a manufacturing apparatus for carrying out the present invention. In FIG. 1, reference numeral 1 is a crucible for melting a metal serving as an alloy material. This crucible 1
Is supported in the vertical direction, and the alloy material is introduced from the upper end. A heating device 5 such as a high frequency induction heating device is installed around the crucible 1.

Reference numeral 3 denotes a nozzle formed at the lower end of the crucible 1, which serves as a pouring port for the molten metal 2 melted in the crucible 1. The nozzle 3 is bent and opened at an angle of about 90 ° with respect to the direction of gravity, and the crucible 1 is opened.
The molten metal 2 is continuously poured by pressurizing the inside with a pressurizing means (not shown).

Reference numeral 4 denotes a rotary cooling body rotatably supported below the crucible 1 for rapidly cooling the molten metal 2 poured from the nozzle 3. At least the inner peripheral surface 4a of the rotary cooling body 4 has a conical shape that widens downward, and the upper and lower ends thereof are opened to have a trumpet shape as a whole. The lower end of the crucible 1 is inserted into the rotary cooling body 4 through the upper opening of the rotary cooling body 4, and the tip of the nozzle 3 is supported so as to be close to the inner peripheral surface 4 a of the rotary cooling body 4. The rotary cooling body 4 is rotatably supported on the outer periphery of the upper end of the frame 7 through a bearing 8 about a rotation center x along the vertical direction. Via drive means not shown,
It rotates in the direction a in FIG.

One of the features of the present invention is that the opening angle θ which is the apex angle of the cone of the inner peripheral surface 4a of the rotary cooling body 4 is 45 to 75 °.
There is that. When the opening angle θ is less than 45 °, the rapidly solidified alloy material is deposited while being attached to the inner peripheral surface 4a of the rotary cooling body 4 by centrifugal force, which is not preferable.
When the opening angle θ exceeds 75 °, it becomes difficult to uniformly supply the molten metal 2 to the inner peripheral surface 4a of the rotary cooling body 4, and the cross section of the foil strip 6 becomes wedge-shaped due to centrifugal force. However, the size and shape of the foil strip become uneven, which is also not preferable. The opening angle θ is more preferably 50 to 70 °.

Next, a method of manufacturing the sendust foil strip of the present invention using this apparatus will be described. First, 84 to 86% by weight, Si: 9.4 to 9.8% by weight, Al: 5.2 to 2. 5.
A metal material prepared to have an alloy composition of 7% by weight is prepared, and the metal material is put into the crucible 1 and heated and melted in the crucible 1 by the heating device 5 to obtain a metal melt 2.

Then, the inside of the crucible 1 is pressurized by a pressurizing means (not shown), the molten metal 2 is pushed out from the nozzle 3 at the lower end of the crucible 1, and the inclined inner peripheral surface 4a of the rotary cooling body 4 rotating at a predetermined speed. Continuously pour near the top of the.

The poured metal melt 2 is pressed against the inner peripheral surface 4a of the rotary cooling body 4 by centrifugal force to be rapidly cooled,
The sendust foil strip 6 becomes the inner peripheral surface 4a of the rotary cooling body 4.
While being pressed upward, it moves downward while rotating in the direction of a in the figure, and is continuously taken out from the opening at the lower end.

The temperature of the molten metal 2 during pouring is preferably 1500 to 1600 ° C. Further, the rotary cooling body 4 is at least 2 by a means such as water cooling.
It is preferably cooled to 0 ° C. or lower, and the rotation speed is preferably set to a peripheral speed of 15 to 100 m / s.

Example A sendust foil strip was manufactured by the following procedure using the manufacturing apparatus shown in FIG. Lumped Fe (Purity 99.99%) 85
After melting wt%, Al (purity 99.99%) 5.4 wt%, and Si (purity 99.999%) 9.6 wt% in a crucible 1 having a high-frequency induction heating device, the temperature was raised to 155
It was kept at 0 ° C. and continuously extruded from the nozzle 3. This molten metal 2 was poured onto the inner peripheral surface of a conical rotary cooling body 4 having an opening angle of 60 ° rotating at a peripheral speed of 20 m / s to obtain a continuous sendust foil strip 6.

FIG. 2 is a 10 × microscopic photograph of the sendust foil strip thus obtained. FIG. 2 (a) shows the roll solidification surface and FIG. 2 (b) shows the free solidification surface. As is clear from FIG. 2, the sendust foil strip produced by the method of the present invention has a smooth surface structure on both the roll solidification surface and the free solidification surface.

FIG. 3 is a 300 × micrograph showing a cross section of the sendust foil strip. The sendust foil strip produced by the method of the present invention has a dense structure composed of crystal grains of 3 to 18 μm.

Comparative Example A molten metal prepared in the same manner as in the above example was used
A copper roll (single roll) having a diameter of 300 mm rotating at 0 rpm was continuously poured and rapidly cooled and solidified to obtain a continuous sendust foil strip.

FIG. 4 is a 10 × micrograph of a Sendust foil strip obtained by the above method, where FIG. 4 (a) shows a roll solidification surface and FIG. 4 (b) shows a free solidification surface. . As is clear from FIG. 4, the product obtained by the one-roll method has a rough surface, and it was not possible to obtain a sendust foil strip having a smooth surface as in the method of the present invention.

Further, FIG. 5 is a 300 × micrograph showing a cross section of the sendust foil strip obtained by the above method. In this way, the sendust foil strip by the one-roll method,
It was composed of crystal grains of 3 to 30 μm, and it was not possible to obtain a dense structure as in the method of the present invention.

Test Example 1 The sendust foil strips obtained in the above Examples and Comparative Examples were heat treated in vacuum at 835 ° C. for 1 hour to prepare crystal grains,
With an AC magnetization characteristic measuring device (made by Tamagawa Machinery Co., Ltd.),
The influence of the frequency on the magnetization in the high frequency region was measured. As a reference example, the magnetic characteristics of the permalloy foil strip were measured in the same manner. The result is shown in FIG.
In the figure, ○-○ is the result of the example, △-△ is the result of the comparative example,
□-□ indicates the result of permalloy.

As shown in FIG. 6, in the case of the sendust foil strip and the permalloy foil strip by the conventional single roll method, 100
Permeability at frequencies of kHz is 400 and 1 respectively
Whereas it was 50, the Sendust foil strip produced by the method of the present invention has a magnetic permeability of 2000,
It was confirmed that the magnetic permeability in the high frequency region was excellent.

Test Example 2 In the above embodiment, the opening angle θ was 20, 30, 45,
Inverted conical rotary cooling bodies of 50, 60, 65, 70, 80, and 90 ° were prepared, and sendust foil strips were manufactured in the same manner as in the above-described examples.

As a result, when the open angles are 20 ° and 35 °, the rapidly solidified Sendust alloy deposits on the inner peripheral surface of the cooling body while adhering to it, and a continuous foil strip cannot be manufactured. It was

When the opening angles are 80 ° and 90 °, it is difficult to uniformly supply the molten metal to the inner peripheral surface of the cooling body, and the centrifugal force due to the rotation of the cooling body is too strong. Therefore, it was not possible to continuously manufacture a foil strip having a uniform size and shape, such as a wedge-shaped cross section of the foil strip.

[0035]

As described above, according to the present invention,
Metal melt prepared to have Sendust alloy composition,
It has an inverted cone shape in which the lower part spreads out and is opened, and by continuously pouring the molten metal on the inner peripheral surface of the rotary cooling body with an opening angle of the cone of 45 to 75 °, the magnetizing property is excellent and the size and shape are A uniform sendust foil strip can be produced continuously.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of an apparatus for carrying out the manufacturing method of the present invention.

FIG. 2 is a photomicrograph showing the surface texture of a sendust foil strip produced by the method of the present invention, (a) showing a roll solidification surface and (b) showing a free solidification surface.

FIG. 3 is a micrograph showing a cross-sectional structure of a sendust foil strip manufactured by the method of the present invention.

FIG. 4 is a micrograph showing a surface texture of a sendust foil strip manufactured by a conventional one-roll method, where (a) shows a roll solidification surface and (b) shows a free solidification surface.

FIG. 5 is a micrograph showing a cross-sectional structure of a Sendust foil strip manufactured by a conventional one-roll method.

FIG. 6 is a chart showing the results of comparison of magnetic characteristics in a high frequency region of a Sendust foil strip manufactured by the method of the present invention with those of a Sendust foil strip and a permalloy alloy produced by a conventional one-roll method.

FIG. 7 is a schematic view showing an example of an apparatus for carrying out a conventional centrifugal quenching method.

[Explanation of symbols]

 1 Crucible 2 Metal Melt 3 Nozzle 4 Rotating Cooling Body 4a Inner Surface 5 Heating Device 6 Sendust Foil Band 7 Rotating Device θ Rotating Cooling Body Inner Surface Opening Angle a Rotating Cooling Body Rotating Direction

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 2, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of an apparatus for carrying out the manufacturing method of the present invention.

FIG. 2 is a micrograph showing a surface structure of a metal composed of a sendust foil strip manufactured by the method of the present invention,
(A) shows a roll solidification surface and (b) shows a free solidification surface.

FIG. 3 is a micrograph showing a cross-sectional structure of a metal composed of a sendust foil strip manufactured by the method of the present invention.

FIG. 4 is a micrograph showing a surface texture of a metal composed of a sendust foil strip manufactured by a conventional one-roll method, where (a) shows a roll solidification surface and (b) shows a free solidification surface.

FIG. 5 is a micrograph showing a cross-sectional structure of a metal composed of a sendust foil strip manufactured by a conventional one-roll method.

FIG. 6 is a chart showing the results of comparing the magnetic characteristics of the Sendust foil strip manufactured by the method of the present invention in the high frequency region with those of the Sendust foil strip and the permalloy alloy produced by the conventional one-roll method.

FIG. 7 is a schematic view showing an example of an apparatus for performing a conventional centrifugal quenching method.

[Explanation of symbols] 1 crucible 2 molten metal 3 nozzle 4 rotating cooling body 4a inner peripheral surface 5 heating device 6 sendust foil strip 7 rotating device θ rotating cooling body inner peripheral surface angle a rotating direction of rotating cooling body

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Isamu Yoshii 2-1-1, Katahira, Aoba-ku, Sendai City, Miyagi Prefecture Tohoku University Institute for Materials Research (72) Inventor, Eihachiro Tanaka 2-chome, Katahira, Aoba-ku, Sendai City, Miyagi Prefecture -1 Inside Tohoku University Institute for Materials Research (72) Ken Masumoto 3-8-22 Uesugi, Aoba-ku, Sendai-shi, Miyagi (72) Akihisa Inoue Kawauchi Muzen, Kawauchi, Sendai-shi, Miyagi 11-806 (72) Inventor Nobuyuki Nishiyama 1-9-9 Yaesu, Chuo-ku, Tokyo Within Imperial Piston Ring Co., Ltd.

Claims (1)

[Claims] 1. Fe: 84 to 86% by weight, Si: 9.4
~ 9.8 wt%, Al: 5.2-5.7 wt%, a metal material having an alloy composition is melted, and the molten metal (2) is continuously poured onto the surface of the rotary cooling body (4). In the method for producing a sendust foil strip which is rapidly cooled and solidified, a conical inner peripheral surface (4) is supported as the rotary cooling body (4) with its rotation center (x) oriented in the up-down direction, and the lower part is widened and opened.
a) and the opening angle (θ) which is the apex angle of the cone of the inner peripheral surface (4a) is 45 to 75 °, and the molten metal (2) is supplied to the rotary cooling body (4). A method for producing a sendust foil strip, which comprises pouring molten metal onto the inner peripheral surface (4a).