JPH04309442A - Production of amorphous alloy thin strip having excellent high-frequency magnetic characteristic - Google Patents

Abstract

PURPOSE:To continuously produce the amorphous alloy thin film by pressuring the molten alloy in an alloy melting crucible and injecting a molten alloy onto a cooling roll rotating at a high speed from a nozzle provided in the bottom of the alloy melting crucible. CONSTITUTION:The nozzle having 0.2 to 0.4mm slit thickness is so disposed as to be positioned approximately perpendicular to the moving direction of the surface of the cooling roll 3 which rotates at 2000 to 3500m/min circumferential speed. The spacing between the tip of the nozzle and the surface of the cooling roll is set at 0.05 to 0.5mm and further, the spacing thereof is held in the reduced pressure atm. or reduced pressure inert gaseous atmosphere kept under 0.01 to 20Torr. A gaseous pressure higher by 0.2 to 0.5kgf/cm<2> than the atm. pressure is applied to the surface of the molten alloy in the alloy melting crucible 1 to extrude the molten alloy. After the molten alloy 2 comes into contact with the surface of the cooling roll, the molten alloy does not come into contact with the front end face of the nozzle and the solidification is completed at the contact length with the roll of 1.2 to 3 times the slit thickness in the rotating direction of the roll. The magnetic core formed by using the thin strip can reduce the heat generation by higher frequencies and contributes to the miniaturization of electronic appliances.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to various noise filters used at high frequencies of 200 KHz or higher,
The present invention relates to a method for manufacturing an amorphous alloy ribbon suitable as a material for wound magnetic cores for noise absorbers, saturable reactors, high-frequency transformers, and other coils and inductance elements.

0002

[Background Art] In recent years, the miniaturization of electronic devices has progressed rapidly.
As a result, market demands for smaller, thinner, and lighter DC stabilized power supplies installed in electronic devices are increasing. In order to miniaturize power supply devices, there is an urgent need to miniaturize coils and inductance components that occupy a large space in power supply circuits. As a means for achieving this goal, development of switching power supply devices whose operating frequency is increased to several hundred KHz or higher is underway. Recently, magnetic cores wound with amorphous alloy ribbons have begun to be used as magnetic core materials for these magnetic components for switching power supplies. Amorphous alloy magnetic materials have electrical resistance about three times higher than normal metals, and because thin materials can be easily obtained through manufacturing processes, they have the property of having low eddy current loss. For this reason, it has characteristics of high magnetic permeability and low core loss in the high frequency region, allowing for miniaturization of magnetic components.
It is highly suitable for meeting the needs for high efficiency. However, even with such amorphous magnetic core materials, as the operating frequency of power supply circuits increases from the conventional tens of KHz to several hundred KHz and even several MHz, it is required to reduce heat generation from the magnetic core as much as possible. It is becoming more and more common.

By the way, in order to reduce the heat generation of the wound magnetic core in the high frequency range, it is effective to reduce the thickness of the amorphous alloy material and increase the electrical resistance to eddy currents. The method for producing amorphous alloy ribbon is generally a single-roll liquid quenching method, in which molten alloy is pressurized and injected onto a cooling roll rotating at high speed through a nozzle with a slit in the bottom of an alloy melting crucible. , a method of continuously producing an amorphous alloy ribbon is used. This method has been widely known as a method for obtaining continuous amorphous alloy ribbons since it was published by a group led by Professor Masumoto of Tohoku University in the Mainichi Shimbun on August 15, 1971. However, with this method, the thickness of the ribbon could be reduced to 18 μm.
If the thickness is reduced below, many pinhole-like holes will occur in the ribbon, which is thought to be due to the entrainment of atmospheric gas, and a good surface quality will not be obtained. I can't get it.

[0004] Furthermore, Japanese Patent Publication No. 5820/1983 describes a planar flow casting method.
ing", and the distance between the nozzle bottom and the cooling surface is 0.
．． Place the nozzle at a position where the diameter is 0.3 to 1 mm, pressurize the molten alloy, and extrude it through the slit provided at the bottom of the nozzle.
A method is disclosed for continuously producing amorphous alloy ribbon by mechanically supporting a uniform layer of molten alloy by both the nozzle bottom and the cooling surface. However, in this method, the thickness of the ribbon is determined by the distance between the cooling surface and the bottom of the nozzle, so in order to obtain a ribbon with a thickness of 10 μm, it is necessary to reduce this distance to nearly 0.01 mm. If the spacing is less than 0.03 mm, a uniform layer of molten alloy will completely solidify between the cooling surface and the bottom of the nozzle, resulting in solid contact and damage to the nozzle. Therefore, it is not possible to obtain a ribbon with a diameter of 20 μm or less using this method. On the other hand, in order to prevent nozzle damage due to solidification of the molten alloy between the cooling surface and the nozzle, it is possible to increase the moving speed of the cooling base material.
If the speed is increased beyond 2000 m/min, the time available for solidification is reduced and the molten alloy does not sufficiently wet the cooling substrate, so a uniform layer of the molten alloy is not maintained, and only a thin porous ribbon with no commercial value is obtained. do not have. Furthermore, in order to prevent solid contact between the cooling base material and the nozzle, there are small restrictions on the shape and dimensions of the nozzle bottom, which causes high costs, and because the bottom area cannot be widened, the slit has insufficient strength and is prone to chipping. It also has In addition, in this method, the ribbon remains on the cooling surface for a long time, so if a roll is used as the cooling base material, depending on the conditions, the ribbon may not separate from the cooling surface and may be carried around the roll. There is a high risk of colliding with the nozzle and damaging it. Therefore, with this method, it is not possible to obtain a thin amorphous alloy ribbon suitable for use as a material for high-frequency magnetic cores.

[0005] Also, Japanese Unexamined Patent Publication No. 63-31
Publication No. 7639 describes a material with a thickness of 10 μm manufactured by injecting an alloy of a specific composition in a vacuum atmosphere.
An ultrathin amorphous alloy with high magnetic permeability and low loss, which also has good surface properties, is disclosed. With this method, the alloy composition range that can be manufactured is narrowly limited, and during manufacturing, the atmosphere while the molten alloy is in contact with the rotary cooling body is limited to 0.01T.
Since it is necessary to create a reduced pressure atmosphere of less than orr or an inert gas atmosphere of less than 60 Torr, the larger the chamber, the longer it takes to vacuum the chamber, and the amount of inert gas used also increases. Furthermore, the thickness of the slit at the tip of the nozzle is very narrow, less than 0.2 mm, and the injection gas pressure is also small, about 0.02 Kg/cm2, making the nozzle easily clogged due to temperature fluctuations of the molten metal during injection.
Although it can be manufactured in a laboratory, it is not suitable for mass production.

Furthermore, in any conventional single-roll liquid quenching method as introduced here, the molten alloy is moved through a predetermined rotation angle while remaining in contact with the roll surface for a certain period of time until it solidifies. During this time, solidification gradually progresses from the roll surface side to the free solidification surface side, and leaves the roll after solidification is completed. Therefore, the flight direction of the ribbon is below the horizontal direction. However, the magnetic domains generated in the thin ribbon produced by the conventional method as described above tend to form elongated 180° domain walls in the longitudinal direction of the thin strip, and domain wall movement becomes the mainstream in the magnetization process. For this reason, the coercive force increases rapidly in a high frequency region of 200 KHz or higher where magnetization rotation is the mainstream. In other words, the magnetic properties of the ribbon obtained when the flight direction of the ribbon is below the horizontal direction are:
Eddy current loss can be reduced by reducing the thickness of the ribbon, but the frequency dependence of coercive force is large and
Although it exhibits good magnetic properties up to about 0 KHz, at higher frequencies, the coercive force increases rapidly and the heat generation of the magnetic core increases. Note that this tendency is particularly noticeable when a nonlinear magnetic core such as a saturable reactor is used with magnetic saturation.

[0007]

[Problems to be Solved by the Invention] As described above, it is impossible to industrially mass-produce ultra-thin amorphous alloy ribbons with a thickness of 20 μm or less using the conventional technology, and in addition, with the conventional technology, The frequency dependence of the coercive force of the magnet increases and the higher the frequency, the greater the coercive force becomes, which causes heat generation in the magnetic core. For this reason, it is not easy to reduce the heat generation of the magnetic core in response to the increasing operating frequency of power supplies, and there is a strong need for a method to industrially produce amorphous alloy ribbons that do not generate heat even at high frequencies. There is.

[0008]

[Means for Solving the Problems] The method for manufacturing an amorphous alloy ribbon according to the present invention solves the problems of the prior art, and
In order to meet the demand for further heat reduction in magnetic cores for various coils and inductance components installed in switching power supplies with operating frequencies of 200 KHz or higher, the plate thickness is 13 μm.
The purpose of the following is to provide a method for manufacturing an ultrathin amorphous alloy strip with a low coercive force in the high frequency range of about 500 KHz to 1 MHz, and the thin strip is thin and rotates in the alternating current magnetization process. As a result of intensive research into methods for producing thin strips that are prone to magnetization, we found conditions that would allow us to produce ultra-thin strips without extremely close distances between the cooling surface and the nozzle. We found that the flight angle greatly affects the high-frequency magnetic properties of the ribbon, especially the coercive force. In other words, by injecting the molten alloy onto a cooling roll rotating at ultra-high speed under a reduced pressure atmosphere and selecting manufacturing conditions such that the ribbon flies out at an angle of 0 to 15 degrees with respect to the tangential direction of the roll, a thin film with excellent high-frequency magnetic properties can be produced. He discovered that it was possible to obtain a belt.

That is, the present invention pressurizes the molten alloy in the alloy melting crucible, injects the molten alloy from a nozzle provided at the bottom of the alloy melting crucible onto a cooling roll rotating at high speed, and continuously forms an amorphous alloy. A method for producing an alloy ribbon, in which a nozzle with a slit thickness of 0.2 to 0.4 mm is rotated at a circumferential speed of 2000 to 3500 m/min so that the slit is perpendicular or almost perpendicular to the direction of movement of the surface of a cooling roll. and the distance between the nozzle tip and the cooling roll surface is 0.0.
5 to 0.5 mm, and the first interval to 0.01 to 0.5 mm.
After maintaining the molten alloy in a reduced pressure atmosphere or a reduced pressure inert gas atmosphere of 20 Torr, a gas pressure 0.2 to 0.5 Kgf/cm2 higher than the above atmospheric pressure is applied to the surface of the molten alloy in the alloy melting crucible, and a cooling roll is applied. By continuously extruding the molten alloy onto the surface, after the molten alloy contacts the cooling roll surface, the molten alloy is 1.2 to 3 times the slit thickness in the roll rotation direction without contacting the nozzle tip surface. Solidification is completed at the roll contact length, and the thin ribbon is made to fly upward at an angle of 0 to 15 degrees with respect to the direction of movement of the cooling roll surface to form an amorphous alloy ribbon with a thickness of 5 to 13 μm. This is a method for manufacturing an amorphous alloy ribbon with excellent high-frequency magnetic properties.

The reasons for limiting the manufacturing conditions in the method for manufacturing an amorphous alloy ribbon according to the present invention will be explained below with reference to FIG. The nozzle 7 is arranged so as to be perpendicular or almost perpendicular to the direction of motion M of the surface of the cooling roll 3 because if this positional relationship deviates, the nozzle 7 is likely to vibrate and the amorphous alloy ribbon 6 will be cut. This is because it becomes a cause. Also, the distance w between the tip surface of the nozzle 7 and the cooling roll 3 is set to 0.
．． 05-0.5mm, preferably 0.1-0.3m
The reason for setting this interval to 0.5 mm or more is that if the distance is 0.5 mm or more, the plate thickness becomes too thick and a ribbon of 13 μm or less cannot be obtained. In order to reduce the thickness of the amorphous alloy ribbon 6, it is better to make this interval w as narrow as possible. This is because, as the interval w increases, the molten metal flow is constricted in the slit width direction and swells in the slit thickness direction before it contacts the cooling roll 3, so the ribbon width becomes narrower and the ribbon thickness becomes thicker. It is. On the other hand, if the distance w between the tip of the nozzle 7 and the cooling roll 3 is less than 0.05 mm, advanced technology is required to control this distance w, which is impractical, and the nozzle and the roll come into contact due to thermal expansion of the nozzle 7, etc. This can easily lead to nozzle damage.

Therefore, it is necessary to rotate the cooling roll 3 at a sufficiently high speed so that the molten alloy 2 does not come into contact with the tip surface of the nozzle 7. In reality, the rotation speed is set so that the amorphous alloy ribbon 6 jumps upward from the horizontal direction, but these conditions include the distance w between the nozzle tip and the cooling roll, the injection temperature of the molten alloy, and the material of the cooling roll. , varies depending on injection gas pressure, atmospheric pressure, atmospheric gas, etc. Usually, when the rotation speed is 2000 to 3500 m/min, it is easy to obtain a good amorphous alloy ribbon. Further, if the speed is less than 2000 m/min, the flying direction of the thin ribbon is directed downward from the horizontal, so that the effects of the present invention cannot be obtained. The faster the rotation speed is, the thinner the molten alloy is stretched, the thinner the ribbon can be, and the faster the solidification rate can be, but there is no problem in manufacturing the ribbon even at a rotation speed of 3500 m/min or more. However, if the cooling roll is rotated at a higher speed than this, the strength of the roll and spindle part due to centrifugal force becomes a problem, which is impractical.

The reason why the gap between the surface of the cooling roll 3 and the tip of the nozzle 7 is maintained in a reduced pressure atmosphere or a reduced pressure inert gas atmosphere of 0.01 to 2 Torr is that if the atmospheric gas exceeds 20 Torr, the molten alloy 2 and the cooling roll 3 are separated. As a result, the surface roughness of the ribbon deteriorates, making it impossible to obtain good magnetic properties. On the other hand, if the temperature is 0.01 Torr or less, the cooling of the ribbon by the atmospheric gas is insufficient, and a completely amorphous state cannot be obtained. In addition, the injection gas pressure (Pe) is 0.2 to 0.5 Kgf/ from the atmospheric gas pressure depending on the rotation speed of the cooling roll.
If the height is increased by cm2, a good thin ribbon can be easily obtained. As the rotational speed of the cooling roll 3 increases, it is necessary to set the injection gas pressure higher in order to stably maintain the puddle formed on the cooling roll. If the injection gas pressure is low, the pool will be unstable and the desired width of the ribbon will not be obtained, or the edge of the ribbon will be thinner than the center and have an irregular shape. On the other hand, if the injection gas pressure is too high, the ribbon thickness cannot be reduced to 13 μm or less.

The thickness of the slit 8 provided at the tip of the nozzle (a
) is 0.2 to 0.4mm, 0.4mm
In this case, the thickness of the ribbon cannot be reduced to 13 μm or less. The smaller the thickness of this slit 8, the easier it is to obtain an ultra-thin ribbon, and if other conditions are constant, the slit thickness a is 0.1 m.
As m increases, the thickness of the ribbon increases by about 3 μm, so dimensional accuracy of the slit thickness is important. On the other hand, if the slit thickness a is less than 0.2 mm, nozzle clogging tends to occur due to variations in manufacturing conditions during operation, making it unsuitable for mass production of ribbons.

Furthermore, it is necessary to complete the solidification of the molten alloy 2 with the roll contact length (b) being extremely short, 1.2 to 3 times the slit thickness 8 in the roll rotation direction. The reason for this is that if the roll contact length b is three times or more the thickness of the slit 8, the flying direction of the amorphous alloy thin plate will be directed downward from the horizontal, so that the effects of the present invention cannot be obtained. On the other hand, the molten alloy 2 forms a stable puddle on the cooling roll 3 due to wetting only with the roll surface and the pressure (Po) at the nozzle tip, but the size of this puddle is 1.5 times the thickness of the slit 8. If it is narrower than 2 times, a stable pool cannot be formed and an amorphous alloy ribbon cannot be produced. Furthermore, the thickness of the amorphous alloy ribbon 6 is set to at least 13 μm in order to minimize eddy current loss as a material for a high-frequency magnetic core and obtain a magnetic core that can be widely used in a high-frequency region of about 100 KHz to 1 MHz.
It is necessary to do the following. However, if the thickness is less than 5 μm, the ribbon tends to bend easily, and the magnetic properties are adversely affected.

The reason why the flight direction of the amorphous alloy ribbon 6 is set at 0 to 15 degrees above the horizontal direction is that when this condition is satisfied, a ribbon with the best high-frequency magnetic properties can be obtained. be. That is, when this condition is satisfied, the molten alloy 2 can be uniformly solidified in the width direction of the ribbon 6 in an extremely short time. At this time, as soon as the molten alloy 2 contacts the cooling roll 3, it solidifies without contacting the nozzle tip and flies out in the tangential direction of the roll, that is, in the horizontal direction. The flight angle at this time is actually 0 to 15 degrees above the horizontal direction. This is because when solidifying the molten alloy, solidification progresses with an extremely short contact length b in the direction of roll rotation, and solidification progresses a moment later on the free solidifying surface side than on the roll surface side. Solidification strain is introduced into the ribbon in the longitudinal direction. Therefore, the ribbon according to the present invention tends to curve toward the free solidification surface. The solidification strain introduced into the ribbon at this time contributes to improving the high frequency magnetic properties. That is, in the method of the present invention, the thickness of the ribbon is small and the surface of the ribbon is very smooth since there are no holes caused by gas entrainment, and magnetic domain formation is hardly affected by surface properties. In addition to this, fine perpendicular magnetic domains develop due to the strain unique to the present invention introduced during solidification. In such a perpendicular magnetic domain, since the ribbon thickness is small, a 180° domain wall is difficult to form even when heat treated. Since such a magnetic domain structure has many domain walls, magnetization rotation occurs more easily than domain wall movement during the magnetization process, and although the coercive force in the low frequency region becomes slightly large, conversely, the coercive force decreases in the high frequency region. The frequency dependence of coercive force becomes small. Therefore, it is possible to suppress the heat generation of the magnetic core to a low level up to a high frequency range of about 1 MHz.

[0017]

EXAMPLE The method of manufacturing an ultrathin amorphous alloy strip having excellent high-frequency magnetic properties according to the present invention is accomplished as follows. In order to carry out the present invention, an apparatus as shown in FIG. 1 was used. That is, the entire apparatus is housed in a vacuum container 10 whose interior is adjusted to a reduced pressure atmosphere or an inert gas atmosphere of 0.01 to 20 Torr, and the alloy melting crucible 1 has a cooling roll 3 close to its lower end and is rotatable. It is located in The nozzle 7 is arranged so as to be perpendicular or substantially perpendicular to the direction of movement M of the surface of the cooling roll 3. As shown in FIG. 2, the most suitable thickness a of the slit 8 of the nozzle 7 provided on the bottom of the alloy melting crucible 1 is 0.3 mm.
This can be selected within the range of 0.2 to 0.4 mm. Further, the width of the slit is selected according to the desired ribbon width.
Further, the distance w between the tip of the nozzle 7 and the cooling roll 3 is 0.05 to 0.5 mm, preferably 0.1 to 0.3 mm.
Set to mm. Here, a tundish may be used instead of the alloy melting crucible 1, but in that case, a means for keeping the temperature of the molten metal constant is required. Further, the alloy melting crucible 1 is configured to melt the alloy therein by a high frequency induction heating device constituted by a high frequency coil 4 surrounding the crucible.

In the present invention, the molten alloy 2 contained in the alloy melting crucible 1 is injected onto the cooling roll 3 which rotates at high speed through the nozzle 7, and is ultra-quenched. A master alloy adjusted to a desired composition is charged, and a molten alloy is obtained by suitable heating means such as a high-frequency induction heating device constituted by a high-frequency coil 4. The rotation speed of the cooling roll 3 is 2000 to 3500 in circumferential speed.
m/min, but the rotational speed is adjusted to the optimum speed within this range depending on the flight angle of the ribbon. As the roll material, a copper alloy or an iron alloy is selected in consideration of wettability with the molten alloy 2 and thermal conductivity.

The gap between the tip end surface of the nozzle 7 and the surface of the cooling roll 3 is set to a reduced pressure atmosphere or a reduced pressure inert gas atmosphere of 0.5 to 1 Torr. If an inert gas is used here, helium, argon or nitrogen are suitable. In order to inject the molten alloy 2 from the nozzle 7 through the slit 8 onto the cooling roll 3, the injection gas 5 is injected into the nozzle according to the circumferential speed of the cooling roll at a pressure difference of +0.2 to atmospheric pressure.
0.5 Kgf/cm2, preferably 0.25 to 0.3 when the peripheral speed of the chill roll is 2500 m/min.
It is introduced so that it becomes Kgf/cm2. During injection of molten alloy, temperature control of molten alloy is important, and optimum injection temperature ±5
It is necessary to control the temperature within a range of °C, which is much narrower than when injecting into the atmosphere. The optimum injection temperature varies depending on the alloy composition, but is generally 60 to 110 degrees higher than the melting point of the alloy.
It is in the high temperature range. If the injection temperature is too high, the ribbon will not be sufficiently cooled, resulting in a brittle ribbon lacking in ductility, and the coercive force of the ribbon will increase abnormally. On the other hand, if the injection temperature is too low, the surface roughness of the ribbon becomes rough and the magnetic properties are significantly affected by the demagnetizing field. The ribbon thus obtained is collected in a flight tube (not shown) having a sufficient length of 5 to 30 m. If the length of the flight tube is short, the ribbon is likely to bend, resulting in poor yield.

[0020]Co68.6Fe3.7Si16B11
．． An alloy having a basic composition of No. 7 to which 0.28 at% of Nb was added for the purpose of improving wettability with a roll was prepared and melted to obtain a master alloy for producing an amorphous alloy. In producing the amorphous alloy ribbon, a single-roll liquid quenching device with a 10 m2 flight tube and capable of reducing the pressure of the entire chamber was used. The manufacturing conditions for the amorphous alloy ribbon were as follows. Nozzle slit shape: 5.08mm x 0.30mm Nozzle material: Quartz Roll material: Copper (roll surface is turned with a diamond tool to a mirror finish) Roll diameter: φ300 (no water cooling) Roll rotation speed: 2500 rpm (peripheral speed 2350 m/
(min) Distance between nozzle bottom and roll surface: 0.15 mm Injection atmosphere gas pressure: 0.5 Torr reduced pressure Atmosphere Injection gas pressure: 0.025 Kg/Roll temperature before injection: 25°C

[0021] Under these conditions, the molten alloy was injected onto the cooling roll, and this process was observed using a high-speed video camera. The molten alloy solidified immediately after contacting the roll, and formed a thin ribbon that spread horizontally. It jumped out about 10 degrees upwards. The dimensions of the amorphous ribbon collected in the flight tube are: thickness 11
．． 4 μm, width 4.8 mm, surface roughness Ra 0
．． It was 1 μm. This ribbon is wound around a core with a diameter of 10 mm with the free solidified surface facing outside the core.
A wound magnetic core was produced. Continue to 5A/m in the magnetic path direction of the wound core.
After strain relief annealing was performed at 400° C. for 1 hour while applying a magnetic field of 100° C., the surface of the magnetic core was coated with epoxy powder to obtain a magnetic core for evaluating magnetic properties. As a comparison material, a ribbon was manufactured using the same apparatus and an alloy of the same composition under the following conditions other than those of the present invention.

[0022] Nozzle slit shape: 5.10mm x 0.
31mm nozzle material: Quartz Roll material: Copper (roll surface is turned with a diamond tool to a mirror finish) Roll diameter: φ300 (no water cooling) Roll rotation speed: 1500 rpm (peripheral speed 1410 m/
) Distance between nozzle bottom and roll surface: 0.2mm Injection atmosphere gas pressure: Atmosphere Injection gas pressure: 0.025Kg/Roll temperature before injection: 25℃

[0023] When the molten alloy was ultra-quenched under these conditions, the molten alloy cooled at a rotational angle of about 3 after contacting the roll.
It solidified while in contact with the roll surface at 0 degrees, and then became a thin ribbon that flew downward at about 7 degrees with respect to the horizontal direction. The dimensions of the amorphous ribbon collected in the flight tube are: thickness 16.8
μm, width 4.95mm, surface roughness Ra 0.5
It was μm. The sample was wound, heat treated, and powder coated under the same conditions as in the present invention to prepare a sample for evaluating magnetic properties. Comparing the characteristic values of magnetic property evaluation samples produced by both methods,
As shown in FIG. 3, the method of the present invention has a lower coercive force than methods other than the present invention, and this tendency becomes more pronounced as the frequency increases. That is, according to the method of the present invention, a magnetic core having a low coercive force and a small frequency dependence of the coercive force can be obtained.

Furthermore, the magnetic core of the present invention has an operating frequency of 150K.
When installed in a commercially available Hz mag-amp type switching power supply and measured the amount of temperature rise of the magnetic core as a mag-amp core, as shown in Table 1, the magnetic core according to the method of the present invention has a higher
Compared to methods outside the present invention, the temperature rise is 2 to 4 degrees Celsius,
Furthermore, the temperature rise was 7 to 15 degrees Celsius lower than that of the commercially available magnetic core installed in the power supply used in this experiment, indicating that the amorphous alloy ribbon produced by the method of the present invention exhibits excellent characteristics as a high-frequency magnetic material. Recognize.

[0025]

[Table 1]

[0026]

[Effects of the Invention] As explained above, according to the present invention, it is possible to obtain an amorphous alloy ribbon having excellent characteristics such as a small coercive force at high frequencies and a small frequency characteristic of the coercive force. . In addition, the magnetic core using the ribbon obtained by the method of the present invention can be used for saturable reactors, noise absorbers (saturable inductance elements), noise filters (for common mode, normal mode, high voltage pulse), etc. By using it as a coil or inductance component used at high frequencies, it is possible to reduce the heat generated by the magnetic core due to high frequencies, and it can greatly contribute to the miniaturization of electronic devices such as switching power supplies.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus used in a manufacturing method according to the present invention.

FIG. 2 is a side sectional view for explaining the relationship between the molten alloy and the cooling roll in the present invention.

FIG. 3 is an explanatory diagram showing the frequency dependence of the coercive force of an amorphous alloy ribbon manufactured by the method of the present invention and an amorphous alloy ribbon manufactured by a method other than the present invention.

[Explanation of symbols]

1 Alloy melting crucible 2
Molten alloy 3
cooling roll 4
High frequency induction heating device 5
Injection gas 6
Amorphous alloy ribbon 7
Nozzle 8 Slit 10 Vacuum container M
Cooling surface roll motion direction a
Slit thickness b
Slit contact length

Claims (1)

[Claims] Claim 1: Pressure is applied to the molten alloy in the alloy melting crucible, and the molten alloy is injected from a nozzle provided at the bottom of the alloy melting crucible onto a cooling roll rotating at high speed to continuously form an amorphous alloy ribbon. In the method of manufacturing, the slit thickness is 0.
．． 2 ~ 0.4 mm nozzle at circumferential speed of 2000 ~ 35
The nozzle is arranged so as to be perpendicular or almost perpendicular to the direction of movement of the cooling roll surface that rotates at 00 m/min, and the distance between the nozzle tip and the cooling roll surface is 0.05 to 0.5 mm.
and after maintaining the interval in a reduced pressure atmosphere or reduced pressure inert gas atmosphere of 0.01 to 20 Torr,
The molten alloy is melted by applying a gas pressure 0.2 to 0.5 Kgf/cm2 higher than the above atmospheric pressure to the surface of the molten alloy in the alloy melting crucible and continuously extruding the molten alloy onto the surface of the cooling roll. After contacting the cooling roll surface, solidification is completed at a roll contact length of 1.2 to 3 times the slit thickness in the roll rotation direction without contacting the nozzle tip surface, and the material is cooled into a thin strip. The thickness is 5 to 1 by projecting upward at an angle of 0 to 15 degrees with respect to the direction of movement of the roll surface.
A method for producing an amorphous alloy ribbon with excellent high-frequency magnetic properties, characterized by forming an amorphous alloy ribbon of 3 μm.