WO2021181512A1 - Production method for fe-based amorphous alloy powder - Google Patents

Abstract

A method for producing an Fe-based amorphous alloy powder, the method comprising: an embrittlement step for heating and embrittling an aggregate body of a foil-shaped Fe-based amorphous alloy; a disintegrating step for roughly fracturing the aggregate body; a screening step for screening the resultant disintegrated bodies for a predetermined size using a screening means to obtain small pieces of the Fe-based amorphous alloy; and a pulverization step for subjecting the small pieces of the Fe-based amorphous alloy to dry pulverization using a pulverization means, wherein the screening means includes a cylindrical body having a large number of through-holes, the cylindrical body is rotated about an axis with the disintegrated bodies placed inside the cylindrical body so that the disintegrated bodies are disintegrated into separate foils, which are in turn divided into small pieces and are caused to pass through the through-holes formed in the cylindrical body.

Description

Method for producing Fe-based amorphous alloy powder

The present invention relates to a method for producing an Fe-based amorphous alloy powder obtained by crushing a foil-shaped Fe-based amorphous alloy obtained by a liquid quenching method.

Since amorphous alloys have excellent soft magnetic properties, they are used in combination with coils as magnetic cores in inductors of various electronic and electrical equipment such as power supply circuits, and electronic components such as reactors, transformers, and filters. Amorphous alloys are obtained by a liquid quenching method in which the molten metal of the alloy is quenched and solidified. Amorphous alloys in thin thickness foil, 10 ⁶ ° C. / sec about, or band that continuous elongated by the method is more cooling rate called single roll method or a double roll method obtained in (ribbon or film) It is obtained in a state, and is called a thin band, a table, a sheet, or the like because of its form. In the present application, a foil-like amorphous alloy having a long and band-like shape is referred to as a thin band. The thickness is preferably 50 μm or less from the viewpoint of amorphization. The term "amorphization" includes not only the case where the alloy is amorphous single phase but also the case where the alloy does not contain the crystal phase as much as possible and the obtained magnetic characteristics are close to the amorphous single phase.

A foil-shaped amorphous alloy produced by a known means is subjected to secondary processing by, for example, winding a thin band to form a ring-shaped wound magnetic core, or cutting or punching the thin band to obtain a predetermined shape. , It is used as a laminated magnetic core made by laminating it. However, in the form of a thin band, the shape of the magnetic core to be formed is limited even if it is used by secondary processing according to the shape of the laminated magnetic core, and it is difficult to form magnetic cores of various shapes with a high degree of freedom. ..

In addition, in the magnetic core used in the frequency range up to several tens of kHz and the magnetic core used under the condition that high DC current is superimposed, the magnetic core is suppressed so as to suppress the decrease in magnetic permeability and the change with respect to the frequency and DC superimposed current. A gap is provided in the magnetic path of the above. For example, in a magnetic core such as a wound magnetic core or a laminated magnetic core, a gap of about 0.5 to 5% of the magnetic path length is formed. Magnetic flux tends to leak from such voids. When the coil is arranged so as to cover the gap, an eddy current is generated by the magnetic flux leaking to the lead wire side constituting the coil (leakage magnetic flux), which causes a problem of increasing the eddy current loss of the electronic component.

For such problems, amorphous alloys are used as a powder form. As the amorphous alloy powder, crushed powder obtained by crushing a thin band is known.

Tokukousho 60-401 is an amorphous alloy in which an amorphous alloy in the form of a ribbon or the like obtained by quenching a melt of an amorphous alloy is annealed into a brittle state, and the brittle amorphous alloy is crushed into a powder. Describes the method for producing powder. The quenching temperature for embrittlement is preferably in the temperature range of 150 ° C to 50 ° C lower than the glass transition temperature of the amorphous alloy. It is stated that stamp mills, crushers, rolls, etc. are included. Although the particle size of the obtained powder is not limited, it is described that the amorphous alloy powder having a particle size of about 25 to 100 μm was obtained from the ribbon-shaped amorphous alloy by the pulverization treatment with a ball mill.

Japanese Patent Application Laid-Open No. 2005-57230 preheats and crushes an Fe-based amorphous metal ribbon to obtain an amorphous metal powder, adds a binder to the obtained amorphous metal powder, mixes the mixture, and then forms a core. , Describes a method for producing an amorphous soft magnetic core in which a molded core is annealed. However, regarding crushing, it only states that a crusher is used, and does not mention a specific method.

International Publication No. 2015/008813 discloses a method for producing a crushed powder of an amorphous alloy ribbon. (a) Before pulverizing, the amorphous alloy strip is subjected to a brittle heat treatment of 320 ° C or higher and 380 ° C or lower. In order to improve the pulverizability in (b), the pulverization step is divided into at least two steps of coarse pulverization and fine pulverization, preferably three steps of coarse pulverization, medium pulverization and fine pulverization. It is described that it is preferable to gradually reduce the particle size in terms of pulverization ability and uniformity of particle size. According to International Publication No. 2015/008813, the embrittlement treatment is performed on a spool in which a thin band is wound, a thin band in an unwound state, or a mass formed by pressing a foil body into a predetermined shape. It is described that it is preferable to carry out the process as a method, and when the thin band is in the state of a spool or a shaped mass, it is desirable to crush it before coarse crushing. Furthermore, different mechanical devices are used in each process from crushing to crushing, crushing to the size of a fist is performed with a compression volume reducer, and coarse crushing into 2 to 3 cm square flakes is performed with a universal mixer, 2 to It is stated that it is desirable to use a crushing and sizing machine for medium crushing of 3 mm square flakes, and to use a pin mill for fine crushing of 100 μm square flakes.

Amorphous alloys are known to have high hardness and are not easily plastically deformed. Therefore, when the amorphous alloy strip is crushed, a large load is applied to the crusher, so that crushed powder that cannot be processed in an overloaded state may accumulate inside and the crusher may stop. Further, when it takes a long time to pulverize, a large internal stress is accumulated in the obtained pulverized powder, and the pulverized powder tends to be inferior in magnetic characteristics. In order to avoid such a problem, there is a method of reducing the load on the crusher by supplying a processed product which has been cut or sheared with a steel blade or a mold in advance to the crusher. However, when an amorphous alloy is cut and sheared, the steel blade and the mold are liable to be worn or chipped, and the durable life thereof is relatively short. In particular, the finer the processed material, the lower the processing amount for the durable life, which causes a problem that the manufacturing cost increases.

As described in Japanese Patent Publication No. 60-401, Japanese Patent Application Laid-Open No. 2005-57230, and International Publication No. 2015/008813, the amorphous alloy is subjected to heat treatment (embrittlement treatment) for embrittlement and pulverized. Measures to make it easier are effective. In addition, as described above, International Publication No. 2015/008813 describes a method of forming a spool in which a thin band is wound when a large amount of amorphous alloy thin band is to be pulverized. In the embrittlement treatment, it is preferable that heat is evenly and uniformly applied to the amorphous alloy, but in the state of a spool, the larger the mass, the larger the temperature difference between the surface side and the inner side, and the inner side. Is more likely to be embrittled at a relatively low temperature compared to the surface side. Further, it may be held at a predetermined temperature for a certain period of time so that the temperature distribution becomes uniform on the surface side and the inner side, but the time held at the predetermined temperature differs between the surface side and the inner side. That is, the crusher needs to crush a mixture of a portion that is easy to crush and a portion that is difficult to crush. In this case as well, a large load may be generated on the crusher.

If the embrittlement treatment is uneven, it takes time to crush the part where the embrittlement is insufficient, and the tendency that the internal stress of the obtained crushed powder increases becomes more remarkable. When the amorphous alloy strip is crushed to obtain crushed powder, processing strain is accumulated in the crushed powder due to the stress applied during crushing. In other words, the stress accumulated inside the pulverized powder (internal stress) increases. When the processing strain (internal stress) becomes large, the powder becomes pulverized powder having a large coercive force. In particular, Fe-based amorphous alloys tend to be pulverized powder having a large coercive force due to the influence of the magnetostriction of the alloy. If the coercive force is large, the hysteresis loss increases, so that the magnetic core loss when the pulverized powder is used to form the magnetic core tends to increase. Therefore, a pulverization method that can obtain a pulverized powder having a small processing strain is desired.

Therefore, an object of the present invention is to provide an optimum production method for obtaining an Fe-based amorphous alloy powder having a small processing strain and a small coercive force.

As a result of diligent research in view of the above objectives, the present inventors have separated the crushed body of the Fe-based amorphous alloy into a foil shape by a sorting means using a cylindrical body or a plate-shaped body having a large number of through holes. At the same time, it was found that the strain given to the crushed powder can be suppressed by dividing into small pieces and sorting, and a Fe-based amorphous alloy powder having a small processing strain and a small coercive force can be obtained, and the present invention was conceived. bottom.

That is, the method of the present invention for producing an Fe-based amorphous alloy powder includes an embrittlement step of heating and embrittlement of a foil-like mass of Fe-based amorphous alloy.
A crushing step of roughly crushing the embrittled agglomerates, and
A sorting step of sorting the obtained crushed material into a predetermined size by a sorting means to obtain small pieces of Fe-based amorphous alloy.
The Fe-based amorphous alloy small piece is provided with a pulverization step of dry pulverization by a pulverization means.
The sorting means includes a cylindrical body having a large number of through holes.
With the crushed body put inside the cylindrical body, the crushed body is rotated around an axis, the crushed body is crushed and separated into a foil shape, and the crushed body is divided into small pieces and formed into the cylindrical body. It is characterized by passing through the through hole.

Another method of the present invention for producing Fe-based amorphous alloy powder is an embrittlement step of heating a foil-like mass of Fe-based amorphous alloy to make it brittle.
A crushing step of roughly crushing the embrittled agglomerates, and
A sorting step of sorting the obtained crushed material into a predetermined size by a sorting means to obtain small pieces of Fe-based amorphous alloy.
The Fe-based amorphous alloy small piece is provided with a pulverization step of dry pulverization by a pulverization means.
The sorting means includes a plate-like body having a large number of through holes, and the sorting means has a plate-like body.
The plate-shaped body is vibrated in a state where the crushed body is put on the plate-shaped body, the crushed body is crushed and separated into a foil shape, and the crushed body is divided into small pieces and formed into the plate-shaped body. It is characterized by passing through the through hole.

The diameter of the through hole formed in the cylindrical body or plate-like body is preferably 30 to 150 mm.

In the crushing step, it is preferable that the average particle size of the crushed powder is 50 to 240 μm.

It is preferable that the crushing means in the crushing step is a pin mill or a hammer mill.

Prior to the embrittlement step, it is preferable to include a lumping step of forming a foil-like Fe-based amorphous alloy into a lump.

The pulverization step comprises a first pulverization step and a second pulverization step. In the first pulverization step, small pieces of Fe-based amorphous alloy selected to a predetermined size are roughly pulverized, and in the second pulverization step, It is preferable to finely pulverize the pulverized powder obtained in the first pulverization step.

It is preferable that the average particle size of the crushed powder is 0.5 to 10 mm in the first crushing step and the average particle size of the crushed powder is 50 to 240 μm in the second crushing step.

The first crushing step consists of a 1-1 crushing step and a 1-2 crushing step. In the 1-1 crushing step, small pieces of Fe-based amorphous alloy selected to a predetermined size are roughly crushed. In the 1-2 crushing step, the crushed powder obtained in the 1-1 crushing step is medium crushed, and in the second crushing step, the crushed powder obtained in the 1-2 crushing step is finely divided. It is preferable to grind.

The average particle size of the crushed powder was set to 2 to 20 mm in the 1-1 crushing step, the average particle size of the crushed powder was set to 0.5 to 4 mm in the 1-2 crushing step, and the crushed powder was set to 0.5 to 4 mm in the second crushing step. The average particle size of is preferably 50 to 240 μm.

It is preferable that the crushing means in the first crushing step is a crushing and sizing machine, and the crushing means in the second crushing step is a pin mill or a hammer mill.

After the pulverization step, it is preferable to include an oxide film forming step of forming an oxide film on the surface of the pulverized powder.

The alloy composition of the Fe-based amorphous alloy powder is Fe _a Si _b B _c C _{d Me} (where M is at least one element selected from the group consisting of Cr, Mo, Mn, Zr and Hf. In atomic%, it is preferably represented by 50 ≦ a ≦ 90, 2 ≦ b ≦ 15, 5 ≦ c ≦ 30, 0 ≦ d ≦ 3, 0 ≦ e ≦ 10, a ＋ b ＋ c ＋ d ＋ e ＝ 100).

The alloy composition of the Fe _{-based amorphous alloy powder is Fe 100-xy} A _x X _y (where A is Cu and / or Au, X is B, Si, S, C, P, Al, Ge, B, Sn and It is represented by at least one element selected from the group consisting of Cr), and is preferably represented by 0 <x ≦ 5 and 10 ≦ y ≦ 24 in atomic%.

According to the present invention, it is possible to provide an optimum production method for obtaining an Fe-based amorphous alloy powder having a small processing strain and a small coercive force.

It is a flowchart which shows an example of the manufacturing process in the manufacturing method of the Fe-based amorphous alloy powder of this invention. It is a schematic diagram which shows an example of the sorting apparatus used in the manufacturing method of the Fe-based amorphous alloy powder of this invention. It is a schematic diagram for demonstrating the structure of a cylindrical body in the sorting apparatus shown in FIG. It is a schematic diagram which shows another example of the sorting apparatus used in the manufacturing method of the Fe-based amorphous alloy powder of this invention. It is a flowchart which shows the other example of the manufacturing process in the manufacturing method of the Fe-based amorphous alloy powder of this invention. It is a flowchart which shows the further example of the manufacturing process in the manufacturing method of the Fe-based amorphous alloy powder of this invention. It is a flowchart which shows the manufacturing process of the powder magnetic core made of Fe-based amorphous alloy powder. It is a front view which shows typically the state which arranged the wound body in the embrittlement heat treatment furnace in the manufacturing method of the Fe-based amorphous alloy powder of this invention. FIG. 5 is a plan view schematically showing a state in which a wound body is arranged in an embrittlement heat treatment furnace in the method for producing an Fe-based amorphous alloy powder of the present invention. It is a graph which plotted the set temperature of the embrittlement heat treatment furnace, and the temperature of the wound body installed in the upper right back and the lower left front in the manufacturing method of the Fe-based amorphous alloy powder of this invention with respect to the elapsed time. It is an SEM observation image of the pulverized powder of Example 1 of this invention. It is a figure which shows the relationship between the temperature of the embrittlement treatment and the average particle diameter. It is an SEM observation image of the pulverized powder of Example 2 of this invention.

Hereinafter, embodiments of the method for producing an Fe-based amorphous alloy powder of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to these embodiments. Further, in a part or all of the figure, a part unnecessary for the explanation is omitted, and there is a part shown by enlarging or reducing the part for facilitating the explanation. In the present specification, the numerical range represented by using "-" means a range including the numerical values before and after "-" as the lower limit value and the upper limit value. In the present specification, the term "process" is included in this term not only as an independent process but also as long as the intended purpose of the process is achieved even if it cannot be clearly distinguished from other processes. Is done.

[1] Method for producing Fe-based amorphous alloy powder The method for producing the Fe-based amorphous alloy powder of the present invention will be described below. FIG. 1 is a flowchart of a manufacturing process in the method for manufacturing a Fe-based amorphous alloy powder of the present invention. As shown in FIG. 1, a foil-shaped Fe-based amorphous alloy powder is used as a material to form a mass of a predetermined size, which is then heated to embrittle and then dry-ground to obtain a desired particle size. To get. If necessary, an oxide film is further formed on the surface of the Fe-based amorphous alloy powder. Hereinafter, each step will be described in detail.

(1) Material As the foil-shaped amorphous alloy used as the material in the present embodiment, for example, a quenching solidification strip obtained by quenching the molten alloy as in the single roll method is used. As the Fe-based amorphous alloy strip, it is preferable to use a Fe-based amorphous alloy strip having a high saturation magnetic flux density Bs of 1.4 T or more. For example, a Fe-based amorphous alloy strip such as Fe-Si-B system represented by Metglas (registered trademark) 2605SA1 material can be used. Further, a composition such as Fe-Si-BC type or Fe-Si-BC-Cr type containing other elements can be adopted. A part of Fe may be replaced with Co, Ni or the like. As an example of the alloy composition of the Fe-based amorphous alloy strip used in the embodiment of the present invention, Fe _a Si _b B _c C _{d Me} (where M is selected from the group consisting of Cr, Mo, Mn, Zr and Hf). It is at least one kind of element, and is represented by 50 ≦ a ≦ 90, 2 ≦ b ≦ 15, 5 ≦ c ≦ 30, 0 ≦ d ≦ 3, 0 ≦ e ≦ 10, a ＋ b ＋ c ＋ d ＋ e ＝ 100) in atomic%. It is preferable that it is made. The alloy composition is not particularly limited, and can be selected according to the required properties.

As the foil-shaped amorphous alloy used as the material in the present embodiment, an amorphous alloy that develops a nanocrystal structure by heat treatment may be used. This is called a nanocrystal alloy, which is in an amorphous state during quenching and solidification, but is subsequently heat-treated to form a nanocrystal structure and exhibits excellent soft magnetic properties. Also in this case, it is produced in the form of a foil-like amorphous alloy, which can be pulverized into pulverized powder and used as a magnetic core material. In this case, it is preferable to use an amorphous alloy strip which is a Fe-based nanocrystal alloy strip having a high saturation magnetic flux density Bs of 1.2 T or more. Specifically, for example, Fe-based nanocrystals such as Fe-Si-B-Cu-Nb series, Fe-Cu-Si-B series, Fe-Cu-B series, and Fe-Ni-Cu-Si-B series. Aluminous alloy strips for alloys can be used. A system in which a part of these elements is substituted and a system in which other elements are added may be used. As an example of the alloy composition used in the embodiment of the present invention, Fe _100-xy A _x X _y (where A is Cu and / or Au, X is B, Si, S, C, P, Al, Ge, B , At least one element selected from the group consisting of Sn and Cr), and is preferably represented by 0 <x ≦ 5, 10 ≦ y ≦ 24 in atomic%. The nanocrystal structure is a microcrystal structure having a particle size of 100 nm or less.

The heat treatment for expressing nanocrystals can be performed, for example, after forming the magnetic core shape or before forming the magnetic core shape and after pulverization. When an amorphous alloy that develops a nanocrystal structure by this heat treatment is used, it is sufficient that the pulverized powder has a nanocrystal structure in the finally obtained dust core or the like. Therefore, at the time of subjecting to pulverization, an amorphous alloy that develops a nanocrystal structure by heat treatment may be used.

The thickness of the foil-like amorphous alloy of the present embodiment is preferably in the range of 10 to 50 μm. If it is less than 10 μm, the mechanical strength is low and it is difficult to stably cast a long alloy strip. Further, if it exceeds 50 μm, a part of the alloy is likely to crystallize. In the present embodiment, a part of the alloy may be crystallized, but the magnetic properties may deteriorate such as a large coercive force. Therefore, considering the influence on the magnetic properties, a crystal phase is formed in the alloy structure. It is preferable that the magnetic properties obtained are close to those of an amorphous single phase without containing as much as possible. The thickness of the foil-like amorphous alloy is more preferably 13 to 35 μm.

Foil-shaped amorphous alloy is an amorphous alloy thin band that has a long shape and is distributed as a large wound body, or a piece of piece that is generated by cutting or punching the thin band as a part other than the necessary part. It may be scrap material.

The width of the thin band is not particularly limited, and a band having a width that is on the market can be used, and a slit is formed from the width that is on the market. A width one can also be used. For example, one having a width of about 100 to 300 mm can be used.

(2) Agglomeration step a1
As a material for the amorphous alloy powder, it is possible to use a foil-like Fe-based amorphous alloy as an amorphous alloy strip as a large wound body, or to use scraps. The offcuts are the residue after removing the amorphous alloy strips of the desired shape, and their sizes and shapes are diverse, and they are very bulky in a disjointed state and are not easy to handle. On the other hand, amorphous alloy strips have a long shape and are distributed as large wound bodies, typically wound bodies with an outer diameter of about 1 to 2 m, and their weight exceeds several hundred kg. In this case as well, it may not be easy to handle as it is. Therefore, it is preferable to make the foil-shaped Fe-based amorphous alloy into a mass having a size and weight that is easy to handle.

In the method for producing an amorphous alloy powder of the present embodiment, when an amorphous alloy strip is used as a material, an amorphous alloy strip is first pulled out from a large roll and then rewound to prepare a lumpy body as a small roll. do. If it is difficult to handle the large wound body as it is due to equipment factors, it is preferable to appropriately prepare a wound body having a suitable size and agglomerate it. When rewinding from a large winding body to a small annular or columnar winding body (mass), the suitable mass thereof is preferably 5 to 50 kg, more preferably 10 to 20 kg, and the outer diameter of the wound body. It is preferably 100 to 400 mm, and more preferably 120 to 150 mm. Further, as a method for producing the wound body, a normal winding method for winding an amorphous alloy strip may be used. For example, the tension at the time of winding is preferably 10 to 100 kPa, and the winding speed is preferably 50 to 150 m / min.

When the material is offcuts, it is preferable to put the offcuts into a mold, press and integrate them to form a lump of offcuts. This facilitates handling. A metal compressor such as a three-way press or a two-way press can be used to produce a lump of offcuts. Further, a one-sided tightening press may be used. By pressing the offcuts with such a press, it is possible to form a lump of offcuts. The size of the lump may be, for example, a rectangular parallelepiped having a side of about 20 cm, and the size of one side is preferably about 10 to 30 cm, more preferably about 15 to 25 cm. If the mass is too small, handling becomes complicated, and if it is too large, the mass increases and handling becomes difficult. The shape of the massive body does not necessarily have to be a rectangular parallelepiped, and may be a polygonal body, a cylindrical body, or a shape close to them. If the shape and mass are easy to handle, the form can be appropriately selected. The pressing force when pressing and integrating the scraps of the amorphous alloy strip is preferably 1 to 500 MPa. If it is less than 1 MPa, it is difficult to make a lump, and if it exceeds 500 MPa, the press becomes large and inefficient, and the amorphous alloy is distorted greatly, and the obtained amorphous alloy powder is obtained. The magnetic characteristics may be inferior. The lower limit of the pressing force is more preferably 5 MPa, still more preferably 10 MPa. The upper limit of the pressing force is more preferably 200 MPa, still more preferably 100 MPa.

(3) Embrittlement step a2
In the present embodiment, it is preferable to heat-treat the agglomerates for embrittlement. This embrittlement treatment is not essential when the thin strips and scraps of the Fe-based amorphous alloy are used as they are without being agglomerated, but even in that case, the embrittlement treatment can improve the pulverizability. Therefore, it is preferable. The heat treatment may be performed in the atmosphere or in a non-oxidizing atmosphere. Although it depends on the composition of the Fe-based amorphous alloy, it has the property of being easily crushed due to embrittlement caused by heat treatment at 250 ° C. or higher. Increasing the temperature of the embrittlement process makes it more embrittled and easier to grind. However, if the temperature is raised too high, crystallization starts, and remarkable crystallization of the pulverized powder is not preferable because it affects an increase in coercive force and an increase in magnetic core loss when used as a dust core, for example. Therefore, in the case of an Fe-based amorphous alloy, the embrittlement treatment temperature is preferably 100 to 220 ° C. lower than the crystallization temperature, and preferably 300 to 400 ° C. The temperature of the embrittlement treatment is more preferably 300 to 380 ° C, still more preferably 320 to 380 ° C, and most preferably 340 to 380 ° C.

In the present invention, if the mass has reached the temperature range of this embrittlement treatment, it is not necessary to hold it at that temperature for a long time, and the holding time of 1 hour or less is sufficient, preferably 30 minutes or less. When embrittlement treatment is performed on a plurality of wound bodies at the same time, the holding time and the reached temperature of each may be different as long as all the wound bodies have reached the above temperature. That is, there may be a difference in temperature depending on the position in the heat treatment furnace, but in that case, it is sufficient that all the wound bodies have reached the predetermined temperature range of the embrittlement treatment, and the respective reached temperature or holding time is It may be different. The temperature of one agglomerate does not have to be uniform as a whole, and at least a part thereof may be in the temperature range of the embrittlement treatment. Depending on the composition of the amorphous alloy, the embrittlement treatment may be omitted.

(4) Crushing process a3
In the present embodiment, it is preferable to perform a crushing treatment on the agglomerates after the embrittlement treatment or the untreated mass. This crushing step is mainly performed on the lumps, and the lumps of the foil-like amorphous alloy that are lumps are roughly crushed. Crushing can be performed by applying an external force using a crushing press or a hammer. At this time, if the mass is wound in the pressurizing direction of the crushing press machine, it is preferable to press and crush the mass in a state where the winding axis directions are the same. Pressurization may be performed from any direction as long as it is a mass obtained from scraps, but it is preferable that there is a flat surface in the pressurization direction. The pressing force of the press is preferably 0.3 ton / kg or more per mass of the mass. This pressing force is defined as a value obtained by dividing the maximum pressing force when crushing with a crushing press by the mass of the wound body to be charged. If this pressing force is less than 0.3 ton / kg, the crushing force is weak and crushing is not sufficient. If the pressing force is greater than 5 ton / kg, the press will be large and inefficient. Therefore, the pressing force of the press in the crushing step is preferably 0.3 to 5 ton / kg per mass of the mass.

(5) Sorting process a4
The morphology of the crushed body after the crushing process of the lump body is in the state of foil-like fragments that are irregularly divided into large and small pieces, or in the state where the foils are stacked in multiple layers and adhere to each other to form a multilayer body. It has become. In particular, when a massive body obtained by rewinding an amorphous alloy strip to form a small wound body is used, many multilayer bodies are present in the crushed body. The crushed body includes a large one having a shape larger than a human fist in a plan view. If the large crushed material cannot be supplied to the crusher in the next crushing process, or the crusher is overloaded due to a large load, unprocessable crushed powder accumulates inside the crusher and the crusher stops. there is a possibility. Further, since it takes time to pulverize, the obtained pulverized powder tends to have a large internal stress and inferior in magnetic characteristics. In the sorting step a4, the crushed body in the multi-layered state is disassembled and separated to reduce the overlap of foils, further divided into small pieces, and the small pieces of Fe-based amorphous alloy are sieved and sorted to a predetermined size. To separate. The small pieces sorted and separated in this way are supplied to the next pulverization step.

The division of the crushed body of the foil-like Fe-based amorphous alloy, in particular, the separation of the multilayer body in which these foils are laminated in multiple layers can be performed by hand, for example, but a large amount of the crushed body of the Fe-based amorphous alloy can be used. Not efficient when trying to process. Therefore, in the present embodiment, the crushed body is divided, separated and sorted by the sorting means using the sorting device 100 as shown in FIG. The sorting device 100 includes a bottomed cylinder 101, which is tilted at an angle of 45 degrees or less so that its central axis CL is parallel to the horizontal installation surface of the device or the bottom side is low. It is rotatably supported by the central axis CL. The cylinder 101 can be rotated around the central axis CL, for example, by a motor (not shown). The cylindrical body 101 has a side surface 105 through which a large number of through holes 107 are formed, and the diameter of each through hole 107 is preferably 3 to 15 cm. ^{It is preferable that 20 or more through holes 107 are formed per unit area (1 m 2} ) of the side surface 105, and as shown in FIG. 3, they are preferably arranged in a staggered pattern.

The crushed body 15 obtained in the crushing step a3 is put into the cylindrical body 101 through the opening on the upper side (left side in the figure) of the cylindrical body 101, and the crushed body 15 is rotationally driven to drive the crushed body 15. Divide, separate and sort. Inside the rotating cylinder 101, there are multiple layers due to the impact caused by the collision of the crushed bodies 15 and the frictional resistance due to the contact when the crushed bodies 15 slide along the inside of the side surface 105 of the cylinder 101. The body is unraveled, the overlapping foils are separated, and the pieces are further divided into small pieces. Of the charged crushed bodies 15, a small piece of Fe-based amorphous alloy having a size capable of passing through the through hole 107 formed on the side surface 105 of the cylindrical body 101 passes through the through hole 107 and cannot pass through the through hole 107. The crushed body 15 of the size is left in the cylindrical body, and the crushed body 15 is continuously crushed and divided. By such a sorting means, a small piece 20 of an Fe-based amorphous alloy having a size corresponding to the hole diameter of the through hole 107 formed on the side surface 105 can be sorted and separated.

In another preferred embodiment, as shown in FIG. 4, a foil-shaped Fe-based amorphous alloy is thrown onto a plate-shaped body 201 having a large number of through holes 107, and the plate-shaped body 201 is vibrated to provide Fe. A sorting device including a vibrating sieve 200 that sifts a basic amorphous alloy through a through hole 107 as a small piece is used as a sorting means. On the plate-shaped body 201, the multilayer body is disassembled by the impact due to the collision between the crushed bodies 15 and the frictional resistance due to the contact between the crushed body 15 and the plate-shaped body 201, the overlapping foils are separated, and the fragments are separated. It is further divided into small pieces. Of the charged crushed bodies 15, a small piece of Fe-based amorphous alloy having a size capable of passing through the through hole 107 formed in the plate-shaped body 201 passes through the through hole 107 and cannot pass through the through hole 107. The crushed body 15 of the above is left in the plate-like body 201, and the crushed body 15 is continuously crushed and divided. From such a sorting means, a small piece 20 of an Fe-based amorphous alloy having a size corresponding to the hole diameter of the through hole 107 formed in the plate-shaped body 201 can be sorted and separated. The hole diameter of the through hole 107, the ^{number of formations per unit area (1 m 2} ), and the arrangement may be the same as those of the above-mentioned cylindrical body 101. The cylindrical body 101 and the plate-shaped body 201 are preferably formed of a punching metal, an etching metal, an expanded metal or the like made of an iron steel plate, a stainless steel plate, aluminum or the like.

(6) Crushing process a5
Next, in the present embodiment, small pieces of the Fe-based amorphous alloy obtained in the sorting step a4 are pulverized. The pulverization is preferably carried out using a pin mill or a hammer mill. A pin mill is a device that has two discs facing each other and a large number of pins planted on the surface of the discs so that they mesh with each other. The small pieces of Fe-based amorphous alloy put into the pin mill are supplied to the center of the disc, and move in the circumferential direction by the centrifugal force generated by the high-speed rotation of one disc or both discs, and are driven by the pins. It is crushed and crushed by impact force and shearing force. The hammer mill crushes and crushes small pieces of Fe-based amorphous alloy by the impact force and shearing force of a high-speed rotating hammer.

According to crushing with a pin mill or a hammer mill, the obtained Fe-based amorphous alloy powder has a flat surface with sharp edges and a surface close to a thin band state, and almost the entire surface is a flaky piece having a flat surface and side surfaces of a fracture surface. It becomes a state. By these methods, it is possible to obtain a pulverized powder having an average particle size of about 240 μm or less and a small processing strain. In the present embodiment, since the processing strain of the pulverized powder can be reduced, an Fe-based amorphous alloy powder having a small coercive force can be obtained. When pulverized powder having a small coercive force is used for a dust core, it is preferable because a magnetic core having a small magnetic core loss and excellent magnetic characteristics can be obtained. As the crushing means, it is more preferable to use a pin mill having a short crushing time that receives processing strain.

As shown in FIG. 5, in the present embodiment, the crushing step a5 may be divided into a first crushing step a5-1 and a second crushing step a5-2. In the first pulverization step a5-1 of the present embodiment, it is preferable to pulverize using a pulverizing and sizing machine. A crushing and sizing machine is a crushing machine having a blade equipped with one or more crushing blades called a cutter or a knife and a cylindrical screen in which the blade is housed. Small pieces of Fe-based amorphous alloy charged into the pulverizer and sizing machine are arranged on the blades that rotate at high speed until they pass through a large number of through holes formed in the screen installed around the rotation axis of the blades. It is crushed and crushed by shearing force or cutting force with a crushing blade. The holes in the screen are rounded or rounded, and if the screen is round, the diameter is smaller than the holes through which the small pieces of Fe-based amorphous alloy pass in the sorting step a4, and the diameter is 1.5 to 12 mm. Is preferable.

The crushed powder obtained by the coarse crushing in the first crushing step a5-1 is finely crushed in the second crushing step a5-2. In the second crushing step a5-2, it is preferable to use a pin mill or a hammer mill as the crusher, and it is more preferable to use a pin mill. In fine pulverization performed using a pin mill or a hammer mill, it is preferable to use pulverized powder having an average particle size of 50 to 240 μm. Further, it is preferable to use a pulverized powder having an average particle size of 50 to 180 μm. Reducing the average particle size of the pulverized powder requires more time for pulverization, so that the processing strain introduced into the pulverized powder tends to increase, which causes an increase in hysteresis loss. However, in the present embodiment, by dividing the crushing step a5 into a plurality of steps, it is possible to crush under the condition of high crushing efficiency, the load on the crusher is reduced, and the accumulation of internal stress in the crushed powder is suppressed. As a result, it is possible to suppress an increase in hysteresis loss even for pulverized powder having a small average particle size. On the other hand, in the pulverized powder having a large average particle size, the fluidity is lowered, the filling property into the mold at the time of molding is deteriorated, and it becomes difficult to increase the density of the dust core. The pulverized powder obtained in the present embodiment has practical fluidity, but if the pulverized powder is flat, its fluidity tends to decrease. Therefore, if good fluidity is to be obtained, the average particle size Is preferably more than 2 times to 6 times or less the thickness of the foil-like amorphous alloy.

As described above, by performing the crushing step a5 separately in the first crushing step a5-1 and the second crushing step a5-2, crushing by coarse crushing is performed in the first crushing step a5-1 to reduce the particle size. The load is reduced to some extent in the crushing in the second crushing step a5-2, but as shown in FIG. 6, the 1-1 crushing step a5-1 is further before the second crushing step a5-2. The coarse pulverization of -1 and the medium pulverization of the first and second crushing steps a5-1-2 may be carried out twice. Further, the first pulverization step a5-1 may be divided into three or more pulverizations to gradually reduce the particle size. If pulverization can be performed under conditions of good pulverization efficiency in each pulverization, the accumulation of internal stress in the pulverized powder can be further suppressed.

In the crushing of the first crushing step a5-1, the 1-1 crushing step a5-1-1, and the 1-2 crushing step a5-1-2, it is preferable to use a crushing and sizing machine for crushing, respectively. The holes of the screen used in the medium crushing of the first 1-2 crushing step a5-1-2 are set to be smaller than the holes of the screen used in the coarse crushing of the first 1-1 crushing step a5-1-1. If the screen has a round hole, the diameter is preferably 0.3 to 5 mm. The holes of the screen used in the coarse crushing of the first crushing step a5-1-1 may be the same as the settings of the first crushing step a5-1.

In the embodiment of the present invention, a pulverized powder having a coercive force Hc of 2000 A / m or less can be obtained. The coercive force Hc of the pulverized powder is preferably 1500 A / m or less, and more preferably 1000 A / m or less. The coercive force Hc is the value of the pulverized powder after pulverization that has not been subjected to the heat treatment for removing strain.

In order to make the particle size of the crushed powder suitable for various uses of the dust core in which the crushed powder is used, the obtained crushed powder may be classified. The classification method is not particularly limited, but the method using a sieve is simple, and a vibrating sieve is particularly preferable. For example, a crushed powder having an average particle size of 100 μm or less can be obtained by passing the crushed powder through a sieve having an opening of 106 μm (diagonal 150 μm) and removing the large crushed powder remaining on the sieve. It is also possible to pass through a sieve with a mesh size of 106 μm (diagonal 150 μm) and put the large pulverized powder remaining on the sieve into the pin mill again for fine pulverization. When it is desired to remove fine pulverized powder, for example, the pulverized powder passing through with a sieve having a mesh size of 32 μm (diagonal 45 μm) can be removed. The size of these sieves may be appropriately set according to the desired size of the pulverized powder.

(7) Oxide film forming step a6
An oxide film may be formed on the surface of the pulverized powder that has undergone the pulverization step a5. The formation of an oxide film is not essential, but it is preferable to form it for rust prevention and insulation. In order to form an oxide film, it is preferable to hydrolyze TEOS (tetraethoxysilane) using ammonia as a catalyst to form a _{SiO 2 film on the surface of the pulverized powder.} It is also preferable to oxidize the surface of the pulverized powder by heating in an atmosphere containing oxygen to form an oxide film derived from the alloy composition on the surface. The heat treatment for oxidation is preferably held in the air at a temperature of 100 to 350 ° C. for 2 to 6 hours, for example.

(8) Strain-removing heat treatment As described above, the pulverized powder obtained by the present embodiment (which has undergone the pulverization step a5) has a coercive force Hc of 2000 A / m or less. By performing a strain removing heat treatment on the pulverized powder, the coercive force can be further reduced. It should be noted that the strain removing heat treatment is often performed after the crushed powder is used to form a dust core, and it is not essential to perform the strain removing heat treatment on the crushed powder in advance. In this strain removing heat treatment, if the foil-like amorphous alloy is a Fe-based amorphous alloy strip such as the above-mentioned Fe-Si-B type, Fe-Si-BC type, Fe-Si-BC-Cr type, they are used. It is preferably carried out at a temperature lower than the crystallization temperature under a temperature condition that does not crystallize. The temperature is preferably 350 ° C. or higher, more preferably 360 ° C. or higher, and even more preferably 380 ° C. or higher. Since the higher the temperature, the more effective the strain removing heat treatment is, it is preferably performed at a temperature close to the crystallization temperature of 350 to 420 ° C., more preferably 360 to 410 ° C., and most preferably 380 to 400 ° C. .. By the strain removing heat treatment, the coercive force of the pulverized powder can be reduced to 200 A / m or less. The coercive force of the pulverized powder after the strain removing heat treatment is preferably 180 A / m or less, more preferably 160 A / m or less, and most preferably 150 A / m or less. This strain removing heat treatment may be performed, for example, with a temperature rise time of about 1 to 6 hours and a holding time of about 0.5 to 4 hours.

When an amorphous alloy that expresses a nanocrystal structure is used, the strain removing heat treatment and the heat treatment that expresses the nanocrystal structure may be performed in combination. The heat treatment temperature is preferably equal to or higher than the crystallization temperature, and is preferably a temperature at which _{ferromagnetic crystals such as Fe 2} B are not generated. The heat treatment temperature is preferably 400 to 600 ° C, more preferably 450 to 550 ° C, and most preferably 500 to 530 ° C.

The strain removing heat treatment may be performed even after the formation of an oxide film on the pulverized powder.

The Fe-based amorphous alloy powder of the present embodiment can be suitably used for a dust core. FIG. 7 is a flowchart of a powder magnetic core manufacturing process using Fe-based amorphous alloy powder. A granulation step c in which a Fe-based amorphous alloy powder and a binder are mixed to obtain a granulated powder, a molding step d in which the obtained granulated powder is pressure-molded to obtain a molded body, and the obtained molded body is heat-treated. The powder magnetic core obtained is obtained by binding flaky Fe-based amorphous alloy powders to each other with a binder. As the binder, it is preferable to use an acrylic resin, polyvinyl alcohol, or the like in order to obtain the strength of the molded product. It is preferable to use low melting point glass or silicone resin in order to obtain the strength of the dust core after the heat treatment, and it is preferable to use them in an appropriate combination. The granulated powder is pressure-molded into a predetermined shape such as a toroidal shape or a rectangular parallelepiped shape using a molding die, but typically, if it is molded at a pressure of 1 to 3 GPa and a holding time of about several seconds. good. In the molding process, it is preferable to consolidate to ^{5.3 × 10 3} kg / m ^{3 or more.} It is preferable to heat-treat the obtained molded product at a temperature lower than the crystallization temperature of the Fe-based amorphous alloy. By the heat treatment, the distortion of the Fe-based amorphous alloy powder due to the pressure applied in the molding process is reduced, and excellent soft magnetic properties can be obtained.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1
(a) Material and agglomeration treatment As a foil-like amorphous alloy, a long Metglas (registered trademark) 2605SA1 material manufactured by Hitachi Metals, Ltd. with a thickness of 25 μm and a width of 213 mm was used. This 2605SA1 material is a Fe-based amorphous alloy strip of Fe-Si-B based material. This Fe-based amorphous alloy strip is manufactured by continuously casting the molten metal on a single roll that rotates at high speed by the liquid quenching method that quenches and solidifies the molten alloy, and winds the obtained strip on a spool. be. This Fe-based amorphous alloy strip was unwound from the spool and rewound to prepare 18 wound bodies (lumps) having a mass of about 10 kg and an outer diameter of 150 mm.

(b) Embrittlement treatment Each of these 18 rolls is placed in a stainless steel container (not shown), loaded appropriately in a heat treatment furnace in a dry air atmosphere, and heat-treated for embrittlement (embrittlement treatment). rice field. The loading state is schematically shown in FIGS. 8 and 9. FIG. 8 is a schematic view viewed from the front, and FIG. 9 is a schematic view viewed in a plane. As shown in FIGS. 8 and 9, the winding body 1 was arranged in the heat treatment furnace in three rows on one side, three in each row, and two stages in the vertical direction. An installation stand (not shown) is provided in the vertical direction, and the winding bodies 1 are separated from each other. Note that in FIGS. 8 and 9, only the positional relationship of each winding body 1 is shown, so that the stainless steel container and the installation stand are not shown.

The brittle treatment is performed in an air atmosphere, and the temperature of the heat treatment furnace is set to 2 hours from room temperature to the maximum temperature and 4 conditions of maximum temperature of 320 ° C, 340 ° C, 360 ° C and 380 ° C. The holding time at the maximum temperature was set to 4 hours, after which the heating was stopped and the mixture was cooled in the furnace. The inside of the furnace is a circulation type, and when heating is stopped, the temperature of the hot air drops and it is gradually air-cooled. FIG. 10 shows a graph in which the set temperature of the heat treatment furnace and the temperature of the wound body installed in the upper right back and the lower left front are plotted against the elapsed time. A thermocouple was attached to each wound body to measure the temperature. The thermocouple was inserted at a position in the middle of the stacking direction of the amorphous alloy strips of the wound body and in the middle of the width direction of the strips. It can be seen that each wound body has almost reached the set temperature, although the temperature change is slightly different due to the different positions in the heat treatment furnace. It was confirmed that there was not much difference in the way these wound bodies were crushed in the subsequent crushing and crushing, and the wound bodies could be crushed without any trouble.

(c) Crushing treatment Next, the embrittled wound body was crushed. In the crushing process, the wound body is placed on a crushing press so that the axial direction of the wound body is the same as the pressurizing direction of the press machine, and the wound body is pressed with a pressing force of 1 ton / kg. And crushed. The crushed body obtained by crushing the wound body had a portion in a multi-layered state in which foil-like amorphous alloys were stacked in multiple layers and partially adhered to each other.

(d) Sorting treatment The multilayer part contained in the crushed body obtained by the crushing treatment is crushed to separate the overlapping foils, and the foil-like amorphous alloy that has become fragments is further divided into small pieces. , The following sorting process was performed. In this embodiment, as shown in FIG. 2, crushed into a bottomed cylinder 101 having a side surface 105 formed with a large number of through holes 107 having a diameter of about 10 cm and having an opening of φ600. The body 15 was thrown in, the cylindrical body 101 was rotated about an axis, and the small pieces of the Fe-based amorphous alloy were sieved by passing through the through holes 107 provided in the side surface 105 of the cylindrical body 101. The Fe-based amorphous alloy small piece 20 falling from the through hole 107 was sent to the next pulverization step by a belt conveyor. The size of the small piece 20 of the Fe-based amorphous alloy (this size is the dimension of the shortest part in the width direction in the direction perpendicular to the thickness direction of the thin band, and if it is rectangular, the width dimension on the shorter side (Corresponding) was about 3 to 10 cm, and also included finer pieces. Since small pieces of Fe-based amorphous alloy are deformable, some of them pass through the 10 cm through hole 107 when bent, but the longest part exceeds 10 cm when stretched into a flat shape. rice field. The obtained Fe-based amorphous alloy small piece 20 has a relationship of approximately L≤1.5M, where L is the dimension of the longest flat portion and M is the dimension of the longest portion in the direction orthogonal to the longest portion. rice field.

(e) Crushing Step Next, a crushing step was carried out in which coarse crushing, medium crushing and fine crushing were sequentially performed. The coarse pulverization corresponds to the 1-1 pulverization step a5-1-1, the medium pulverization corresponds to the 1-2 pulverization step a5-1-2, and the fine pulverization corresponds to the second pulverization step a5-2. The coarse crushing of the first 1-1 crushing step a5-1-1 was carried out by using a crushing and sizing machine. The crushed material was continuously put into a crushing and sizing machine equipped with a screen with a hole with a diameter of 4 mm, and the crushing blade was rotated at high speed for crushing. The size of the pulverized powder obtained by this coarse pulverization is such that it can pass through a hole having a diameter of 4 mm.

For the medium crushing of the first 1-2 crushing steps a5-1-2, the same crushing and sizing machine was used, and the coarsely crushed powder obtained by the coarse crushing was crushed and sized with a screen having a hole with a diameter of 1.5 mm. The crushing blade was rotated at high speed for crushing. The size of the crushed powder obtained by pulverization is such that it can pass through a hole having a diameter of 1.5 mm.

For the fine pulverization in the second pulverization step a5-2, medium pulverized powder was continuously charged using a pin mill, and a disk equipped with several hundred pins was pulverized by rotating at high speed. As a result, an amorphous alloy crushed powder was produced. FIG. 11 shows an SEM observation image of the pulverized powder (embrittlement treatment 360 ° C.) obtained by this pin mill. The pulverized powder crushed by this pin mill had a flat surface with sharp edges and a surface close to the original thin band state.

The average particle size of the obtained amorphous alloy crushed powder (crushed powder obtained by crushing in the second crushing step a5-2) was determined. The particle size of the pulverized powder was measured by sieving into a predetermined particle size category using about 20 g of the pulverized powder and measuring the mass of each particle size category. The particle size classification is based on the nominal opening of the JIS test sieve (JIS Z8801-1: 2006) of the sieve used for the sieve, and each particle size classification is 45 μm or less, 45 μm or more 63 μm or less, 63 μm or more 90 μm or less, 90 μm. The range was set to the range of more than 125 μm, more than 125 μm, more than 180 μm, more than 180 μm and less than 355 μm, more than 355 μm and less than 425 μm, and more than the minimum particle size and less than the maximum particle size. Assuming that all the particles included in each particle size category are the average diameter of the particle size category, the total of (average diameter x mass) was divided by the total mass to obtain the average particle size. In the present invention, the "average particle size" is based on this calculation method.

The pulverized powder obtained in Example 1 has an average particle size of 184 μm at 320 ° C. for embrittlement treatment, 107 μm at 340 ° C. for embrittlement treatment, 88 μm at 360 ° C. for embrittlement treatment, and 75 μm at 380 ° C. for embrittlement treatment. Was there. In each case, the powder passed through a sieve having an opening of 425 μm, and there was no powder remaining on the sieve, or even if there was, the amount was so small that it had substantially no effect on determining the average particle size. Figure 12 shows the relationship between the embrittlement treatment temperature and the average particle size. In this example, the average particle size became smaller as the embrittlement heat treatment temperature was increased. This indicates that the higher the temperature of the embrittlement heat treatment, the easier it is to pulverize. In this example, Fe-based amorphous alloy powder having an average particle size of 75 to 184 μm was obtained.

Example 2
In the second pulverization step a5-2, an Fe-based amorphous alloy powder was obtained in the same manner as in Powder C of Example 1 (under the conditions of embrittlement treatment 360 ° C.) except that a disk-type vibration mill was used as the pulverizer. The disc-type vibration mill crushes the sample in the container by pressure and grinding by causing planetary motion between the ring and the stone in the sample container that are swung by the motor. The crushing was carried out by adding 50 g of crushed powder and operating for 1 minute. The size of the obtained Fe-based amorphous alloy powder was almost the same as that of powder C. The SEM observation image of the pulverized powder of Example 2 is shown in FIG. The pulverized powder of Example 2 contained a large amount of pulverized powder having rounded corners and a rough surface as compared with powder C crushed by a pin mill. The coercive force of the powder C and the pulverized powder of Example 2 was evaluated by both the pulverized powder which had not been subjected to the strain removing heat treatment and the pulverized powder which had been subjected to the strain removing heat treatment at 420 ° C. The results are shown in Table 1.

For the coercive force, a vibrating sample magnetometer (model: VSM-5-20) manufactured by Toei Kogyo Co., Ltd. was used, with an outer diameter of 7 mmφ, an inner diameter of 6 mmφ, and a height of 5 mm (sample filling height 2 mm). ) Was filled with 100 mg of crushed powder and measured with a measurement magnetic field of 10 kOe (800 kA / m).

The crushed powder after crushing in Example 2 has a coercive force of about 4 times as large as that of the crushed powder after crushing in Example 1 (powder C). It is presumed that the force to grind the powder always works in the crushing with the disc type vibration mill, and the residual stress inside the powder is larger than that in the case of crushing with the pin mill. Therefore, it can be seen that it is preferable. The coercive force Hc of Example 2 was relaxed by stress relaxation heat treatment and was greatly improved.

Example 3
The embrittlement treatment was performed with the maximum temperature set to 300 ° C and the holding time at the maximum temperature set to 2 hours as the temperature setting of the heat treatment furnace. Grinding with a crushing and sizing machine equipped with a perforated screen; the same conditions as the coarse crushing of the 1-1 crushing step a5-1-1 performed in Example 1) and three types of crushers (disc type vibration). Three types of amorphous alloy pulverized powders were prepared in the same manner as in Example 1 except that the second pulverization step a5-2 was performed using a mill, a hammer mill, and a pin mill). The obtained three types of pulverized powders were classified so as to pass through a sieve having a particle size of 150 μm and not to pass through a sieve having a particle size of 75 μm. The pulverized powder which had not been subjected to the strain removing heat treatment and the pulverized powder which had been subjected to the strain removing heat treatment at 360 ° C., 380 ° C. and 400 ° C. were prepared, and the coercive force Hc was measured in the same manner as in Example 2. The results are shown in Table 2.

As shown in Table 2, the pulverized powder obtained by finely pulverizing using a hammer mill or a pin mill is retained both after pulverization (without strain removing heat treatment) and after strain removing heat treatment as compared with a disc mill. It can be seen that the magnetic force Hc is extremely small. That is, it can be seen that the hammer mill and the pin mill are crushers that can obtain crushed powder having a small processing strain. When the Fe-based amorphous alloy strip is used, it is possible to obtain a crushed powder having a coercive force Hc of 2000 A / m or less in the crushed powder after crushing (without the strain removing heat treatment). Further, after the strain removing heat treatment, pulverized powder having a coercive force Hc of 200 A / m or less can be obtained.

The coercive force of the Fe-based amorphous alloy strip (Metglas (registered trademark) 2605SA1 material manufactured by Hitachi Metals Co., Ltd.) used for crushing was measured (average of 5 samples measured), and the coercive force was 60 A / m. there were. The measurement of the coercive force was the same as the measurement of the pulverized powder, and the thin strips cut into a size that fits in the sample case were stacked and filled in the sample case. The Fe-based amorphous alloy powder has a larger coercive force than the thin band before crushing. However, it can be seen that the holding force is improved by the strain removing heat treatment, and the increase in the coercive force is suppressed according to the present invention.

Example 4
Using Metglas (registered trademark) 2605SA1 material (thickness 25 μm) manufactured by Hitachi Metals, Ltd. as the end material of the amorphous alloy thin band, the lump state of the end material of the Fe-based amorphous alloy thin band is as follows. Made. Approximately 10 kg of scrap was compressed with a two-way press to prepare a plurality of rectangular parallelepipeds of approximately 20 × 15 × 25 mm. This rectangular parallelepiped is in a state where irregularities are formed on the surface. This rectangular parallelepiped is made into a lump of scraps. The lump state of this offcut was appropriately loaded into a heat treatment furnace in a dry air atmosphere, and embrittlement heat treatment was performed. The embrittlement heat treatment was carried out in the same manner as in Example 1 except that the maximum temperature was set to 360 ° C.

Next, crushing treatment was performed on the lump state of the embrittled heat-treated offcuts. In the crushing step, a lump of scrap was placed in a crushing press and pressed with a pressing force of 1 ton / kg to crush it. The crushed body obtained by the crushing treatment is put into a cylindrical body having a side surface having a large number of through holes having a diameter of about 10 cm in the same manner as in Example 1, and the cylindrical body is rotated about an axis. Then, it was divided into small pieces of Fe-based amorphous alloy and sorted. The size of the obtained small piece (this size is the dimension of the shortest part in the width direction in the direction perpendicular to the thickness direction of the thin band, and if it is rectangular, it corresponds to the width dimension on the short side). Was about 3 to 10 cm. The small pieces of the Fe-based amorphous alloy were crushed in the same manner as in the crushing step performed in Example 1 to obtain crushed powder of the Fe-based amorphous alloy. The average particle size of the obtained pulverized powder was 86 μm. The coercive force of the pulverized powder was almost the same as that of the powder C of Example 1.

Comparative example 1
In the same manner as in Example 4, the crushed body obtained by performing the agglomeration treatment, the embrittlement treatment, and the crushing treatment from the scraps of the amorphous alloy strip is roughly crushed by hand into a disk type vibration mill. The powder was charged and crushed until the average particle size of the crushed powder became 88 μm to prepare a crushed powder of Fe-based amorphous alloy. Most of the obtained pulverized powder had rounded corners, and the surface was also rough. The coercive force of the crushed powder was as large as 4140 A / m. This pulverized powder was subjected to a strain removing heat treatment at 340 ° C., but the degree of improvement in coercive force was inferior to that of the examples of the present invention.

Claims (14)

1. An embrittlement process that heats and embrittles a foil-like mass of Fe-based amorphous alloy.
   A crushing step of roughly crushing the embrittled agglomerates, and
   A sorting step of sorting the obtained crushed material into a predetermined size by a sorting means to obtain small pieces of Fe-based amorphous alloy.
   The Fe-based amorphous alloy small piece is provided with a pulverization step of dry pulverization by a pulverization means.
   The sorting means includes a cylindrical body having a large number of through holes.
   With the crushed body put inside the cylindrical body, the crushed body is rotated around an axis, the crushed body is crushed and separated into a foil shape, and the crushed body is divided into small pieces and formed into the cylindrical body. A method for producing an Fe-based amorphous alloy powder through which a through hole is formed.
2. An embrittlement process that heats and embrittles a mass of foil-like Fe-based amorphous alloy.
   A crushing step of roughly crushing the embrittled agglomerates, and
   A sorting step of sorting the obtained crushed material into a predetermined size by a sorting means to obtain small pieces of Fe-based amorphous alloy.
   The Fe-based amorphous alloy small piece is provided with a pulverization step of dry pulverization by a pulverization means.
   The sorting means includes a plate-like body having a large number of through holes, and the sorting means has a plate-like body.
   The crushed body is vibrated in a state where the crushed body is put on the plate-shaped body, the crushed body is crushed and separated into a foil shape, and the crushed body is divided into small pieces and formed into the plate-shaped body. A method for producing an Fe-based amorphous alloy powder through which a through hole is formed.
3. In the method for producing an Fe-based amorphous alloy powder according to claim 1 or 2.
   A method for producing an Fe-based amorphous alloy powder, wherein the through-holes formed in the cylindrical or plate-like body have a diameter of 30 to 150 mm.
4. In the method for producing an Fe-based amorphous alloy powder according to any one of claims 1 to 3,
   A method for producing an Fe-based amorphous alloy powder, wherein the average particle size of the crushed powder is 50 to 240 μm in the crushing step.
5. In the method for producing an Fe-based amorphous alloy powder according to any one of claims 1 to 4,
   A method for producing an Fe-based amorphous alloy powder, wherein the crushing means in the crushing step is a pin mill or a hammer mill.
6. In the method for producing an Fe-based amorphous alloy powder according to any one of claims 1 to 5,
   A method for producing an Fe-based amorphous alloy powder, comprising a lumping step of forming a foil-like Fe-based amorphous alloy into a lump before the embrittlement step.
7. In the method for producing an Fe-based amorphous alloy powder according to any one of claims 1 to 6,
   The crushing step comprises a first crushing step and a second crushing step.
   In the first pulverization step, small pieces of Fe-based amorphous alloy selected to a predetermined size are coarsely pulverized.
   A method for producing an Fe-based amorphous alloy powder, in which the pulverized powder obtained in the first pulverization step is finely pulverized in the second pulverization step.
8. In the method for producing an Fe-based amorphous alloy powder according to claim 7,
   A method for producing an Fe-based amorphous alloy powder, wherein the average particle size of the crushed powder is 0.5 to 10 mm in the first crushing step, and the average particle size of the crushed powder is 50 to 240 μm in the second crushing step.
9. In the method for producing an Fe-based amorphous alloy powder according to claim 7,
   The first crushing step comprises a 1-1 crushing step and a 1-2 crushing step.
   In the 1-1 crushing step, small pieces of Fe-based amorphous alloy selected to a predetermined size are roughly crushed.
   In the 1-2 crushing step, the crushed powder obtained in the 1-1 crushing step is medium crushed.
   A method for producing an Fe-based amorphous alloy powder, in which the pulverized powder obtained in the 1-2 pulverization steps is finely pulverized in the second pulverization step.
10. In the method for producing an Fe-based amorphous alloy powder according to claim 9,
    The average particle size of the crushed powder was set to 2 to 10 mm in the 1-1 crushing step, the average particle size of the crushed powder was set to 0.5 to 4 mm in the 1-2 crushing step, and the crushed powder was set to 0.5 to 4 mm in the second crushing step. A method for producing an Fe-based amorphous alloy powder having an average particle size of 50 to 240 μm.
11. In the method for producing an Fe-based amorphous alloy powder according to any one of claims 7 to 10.
    A method for producing an Fe-based amorphous alloy powder, wherein the crushing means in the first crushing step is a crushing and sizing machine, and the crushing means in the second crushing step is a pin mill or a hammer mill.
12. In the method for producing an Fe-based amorphous alloy powder according to any one of claims 1 to 11.
    A method for producing an Fe-based amorphous alloy powder, comprising an oxide film forming step of forming an oxide film on the surface of the crushed powder after the crushing step.
13. In the method for producing an Fe-based amorphous alloy powder according to any one of claims 1 to 12,
    The alloy composition of the Fe-based amorphous alloy powder is Fe _a Si _b B _c C _{d Me} (where M is at least one element selected from the group consisting of Cr, Mo, Mn, Zr and Hf. Production of Fe-based amorphous alloy powder represented by 50 ≦ a ≦ 90, 2 ≦ b ≦ 15, 5 ≦ c ≦ 30, 0 ≦ d ≦ 3, 0 ≦ e ≦ 10, a ＋ b ＋ c ＋ d ＋ e ＝ 100) in atomic% Method.
14. In the method for producing an Fe-based amorphous alloy powder according to any one of claims 1 to 12,
    The alloy composition of the Fe _{-based amorphous alloy powder is Fe 100-xy} A _x X _y (where A is Cu and / or Au, X is B, Si, S, C, P, Al, Ge, B, Sn and A method for producing an Fe-based amorphous alloy powder, which is represented by (at least one element selected from the group consisting of Cr) and represented by 0 <x≤5 and 10≤y≤24 in atomic%.

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