JP2021118349A - Metal leaf manufacturing method - Google Patents

Abstract

Kind Code: A1 A metal foil made of an amorphous soft magnetic material is produced which can be crystallized into a nanocrystalline soft magnetic material with crystals of a uniform size by uniformly heating the metal foil. provide a way. A metal foil (10) made of an amorphous soft magnetic material is brought into close contact with an installation surface (21) of a metal base (2), and the metal foil (10) is heated while being brought into close contact with the installation surface (21). Crystallize 10 amorphous soft magnetic materials into nanocrystalline soft magnetic materials. During crystallization, the heating temperature Tt is equal to or higher than the crystallization start temperature Ts at which the nanocrystalline soft magnetic material is crystallized, and is higher than the temperature Ta of the metal foil, which is raised by self-heating during crystallization. By heating the metal foil 10 at a heating temperature Tt at which the temperature of the mounting surface is also lowered, the amorphous soft magnetic material is crystallized, and the heat generated by the metal foil 10 during crystallization is transferred to the base 2. absorb heat. [Selection drawing] Fig. 4

Description

The present invention relates to a method for producing a metal foil made of a nanocrystalline soft magnetic material.

In conventional motors and transformers, a laminated body in which metal foils are laminated is used as a core. For example, Patent Document 1 describes the production of a metal foil that crystallizes an amorphous soft magnetic material of a metal foil into a nanocrystalline soft magnetic material by heating a metal foil made of an amorphous soft magnetic material in a laminated state. A method has been proposed.

JP-A-2017-141508

Here, it is generally known that when an amorphous soft magnetic material is crystallized into a nanocrystalline soft magnetic material, the material self-heats, and the self-heating temperature at the time of self-heating is It is known that the temperature is higher than the temperature at which crystallization of the material begins. Therefore, for example, as shown in Patent Document 1, when the metal foils are heated in a laminated state, self-heated heat may be trapped between the metal foils, and the metal foils may be excessively heated. Further, among the laminated metal foils, the heating temperatures of the metal foils inside and the metal foils located on the outside also vary. As a result, the size of the crystals of the metal foil varies.

In view of these points, it is conceivable to heat the metal foils one by one on the heated base without laminating the metal foils. However, for example, when the metal foil is warped, the portion of the metal foil that is not in contact with the base may occupy a large proportion, and the temperature of the metal foil varies during crystallization. In particular, heat tends to be trapped in the gap formed between the metal foil portion that is not in contact with the base and the base, and this portion becomes excessively heated and the crystal grains become coarse. As a result, the crystal size of the metal foil may vary, and the magnetic properties of the metal foil may deteriorate.

The present invention has been made in view of these points, and is a nanocrystal system of crystals having a uniform size by uniformly heating the metal foil with respect to the metal foil made of an amorphous soft magnetic material. An object of the present invention is to provide a method for producing a metal foil that can be crystallized into a soft magnetic material.

The method for producing a metal foil according to the present invention is a method for producing a metal foil made of a nano-crystalline soft magnetic material, and the manufacturing method includes a step of preparing a metal foil made of an amorphous soft magnetic material and a step of preparing the metal foil. By heating the metal foil while keeping the metal foil in close contact with the base so that the prepared metal foil imitates the installation surface of the metal base, the amorphous soft magnetic material of the metal foil is made into the nano. In the step of crystallization, which includes a step of crystallization into a crystalline soft magnetic material, the heating temperature is equal to or higher than the crystallization start temperature at which the nanocrystalline soft magnetic material is crystallized, and when crystallization is performed. By heating the metal foil at a heating temperature at which the temperature of the installation surface is lower than the temperature of the metal foil, which is raised by self-heating, the amorphous soft magnetic material is crystallized while being crystallized. It is characterized in that the heat of the self-heating at the time of crystallization is absorbed by the base.

In the present invention, first, a metal foil made of an amorphous soft magnetic material is prepared. Next, the amorphous soft of the metal foil is formed by heating the metal foil in a state of being in close contact with the installation surface while keeping the metal foil in close contact with the base so that the metal foil imitates the installation surface of the metal base. Crystallize the magnetic material into a nano-crystalline soft magnetic material. At this time, the temperature of the installation surface is higher than the temperature of the metal foil, which is a heating temperature equal to or higher than the crystallization start temperature at which the nanocrystalline soft magnetic material is crystallized and is raised by self-heating during crystallization. Heat the metal foil at a lower heating temperature. As a result, the amorphous soft magnetic material of the metal foil is crystallized, and the temperature of the base installation surface is lower than the temperature of the self-heated metal foil, so that the self-heated heat is absorbed from the base installation surface to the base. be able to. Here, since the metal foil is in close contact with the base, the heat of the metal foil is uniformly absorbed by the base, and the temperature of the metal foil becomes uniform during crystallization. Therefore, the crystals of the metal foil can be crystallized into crystals having a uniform size. As a result, it is possible to suppress a decrease in the magnetic properties of the metal foil due to the variation in the size of the crystal grains (specifically, the coarsening of the crystal grains).

When heating the metal foil in the crystallization step, for example, the metal foil may be heated by heat from a heater or heat from hot air from a position facing the base with the metal foil sandwiched between them. However, in a more preferred embodiment, in the crystallization step, the metal foil is heated by a heater built in the base.

According to this aspect, the heater built in the base can uniformly heat the installation surface of the base, and the heated heat can uniformly heat the metal foil. Furthermore, since the temperature of the installation surface is lower than the temperature of the metal foil that self-heats during crystallization and the temperature of the installation surface is uniform, the self-heat of the metal foil is uniformly transferred from the installation surface to the base. It can absorb heat.

If the metal foil can be brought into close contact with the base without warping, for example, a magnet or an electromagnet may be provided on the base and the metal foil may be brought into close contact with the base by magnetic force. However, in a more preferred embodiment, when the metal foil is brought into close contact with the base in the crystallization step, the metal foil is sucked from a suction port formed on the base to bring the metal foil into contact with the base. Adhere to the base.

According to this aspect, by sucking the metal foil from the suction port formed on the base, the warp of the metal foil can be corrected and the metal foil can be brought into close contact with the surface of the base without any gap. Further, even if foreign matter or the like is present on the surface of the base, it is possible to suck the foreign matter from the suction port, and it is possible to prevent the foreign matter from getting caught between the metal foil and the base.

In a more preferred embodiment, in the step of preparing the metal foil, the molten metal obtained by melting the material of the metal foil is sprayed onto a rotating roll, and the molten metal is cooled and solidified on the roll. When the metal foil made of the amorphous soft magnetic material is produced and the metal foil is brought into close contact with the base, the surface of the metal foil that is in contact with the roll is treated as described above. Adhere to the installation surface.

According to this aspect, the molten metal obtained by melting the metal foil material is sprayed onto a rotating roll, and the molten metal is cooled and solidified on the roll, that is, a so-called single roll method, which is an amorphous soft magnetic structure. The metal foil made of a material is manufactured. Of the surfaces of the metal foil thus obtained, the surface on the side that was in contact with the roll has less unevenness than the surface on the opposite side, so that the surface of the metal foil is used as the base installation surface. Therefore, the metal foil can be uniformly adhered, and the metal foil can be uniformly heated in this uniform adhesion state. As a result, uniform crystallization of the metal foil is promoted, and non-uniform plastic deformation due to shrinkage during crystallization can be suppressed, so that the crystallized metal foil can be laminated more densely.

Further, as a preferred embodiment, in the step of preparing the metal foil, as the metal foil, a metal foil made of an iron-based amorphous soft magnetic material is prepared, and the step of crystallizing the metal foil is performed on the support member. By arranging the metal foil and moving at least one of the base and the support member in a direction in which the base and the support member approach each other, the metal foil is placed between the base and the support member. The metal foil is sandwiched and brought into close contact with the base, and the metal foil is heated by a heater built in the base. In the step of crystallizing, the following (i) or (ii) Satisfy the conditions. (I) The thermal conductivity of the material constituting the support member is 0.2 W / mK or less. (Ii) The temperature of the support member is set to 300 ° C. or higher and lower than the crystallization start temperature.

According to this aspect, since the support member on which the metal foil is arranged can be relatively close to the base, the metal foil is sandwiched between the base and the support member, and the metal foil is made more uniform by the base. Can be brought into close contact.

At this time, the metal foil is heated by a heater built in the base, and the metal foil crystallizes. (I) The thermal conductivity of the material constituting the support member is set to 0.2 W / mK or less. As a result, heat is not easily taken away by the support member. Specifically, even if the temperature distribution of the installation surface of the base is biased when it comes into close contact with the metal foil due to the distortion and the shape of the warp of the metal foil, the heat of the metal foil is taken away by the support member. It becomes difficult to break and the temperature distribution of the metal foil can be made uniform. As a result, it is possible to suppress a local temperature drop on the installation surface of the base while the metal foil is in close contact with the base. As a result, uniform crystallization of the metal foil is promoted, and non-uniform plastic deformation due to shrinkage during crystallization can be suppressed, so that the crystallized metal foil can be laminated more densely.

Here, when the thermal conductivity of the material constituting the support member exceeds 0.2 W / mK, the heat of the installation surface of the base easily escapes to the support member via the metal foil. Therefore, even if the temperature distribution on the installation surface of the base is biased when the metal foil and the base are in close contact with each other, it is difficult for the bias to become uniform, and the crystallization of the metal foil is prioritized from the high temperature portion. Since it is started, the timing of contraction associated with crystallization differs depending on the site. As a result, non-uniform plastic deformation occurs in the metal foil, and the crystallized metal foil may not be densely laminated.

On the other hand, when the metal foil is crystallized by being heated by a heater built in the base, (ii) even if the temperature of the support member is 300 ° C. or higher and lower than the crystallization start temperature of the metal foil, the base is used. Since the temperature difference from the support member is small, the heat of the base is not easily taken away by the support member. Specifically, even if the temperature distribution of the installation surface of the base is biased when the metal foil and the base are in close contact with each other due to the shape of the metal foil such as waviness, the heat of the metal foil is applied to the support member. It is hard to be robbed and the temperature distribution of the metal foil can be made uniform. As a result, it is possible to suppress a local temperature drop on the installation surface of the base while the metal foil is in close contact with the base. As a result, uniform crystallization of the metal foil is promoted, and non-uniform plastic deformation due to shrinkage during crystallization can be suppressed, so that the crystallized metal foil can be laminated more densely.

Here, when the temperature of the support member is less than 300 ° C., the heat of the installation surface of the base easily escapes to the support member via the metal foil. Therefore, when the temperature of the installation surface varies, the progress of crystallization of the metal foil differs depending on the site according to the temperature variation, so that the timing of shrinkage due to crystallization differs depending on the site. As a result, non-uniform plastic deformation occurs in the metal foil, and the crystallized metal foil may not be densely laminated. On the other hand, when the temperature of the support member is equal to or higher than the crystallization start temperature of the metal foil, the metal foil crystallizes when the metal foil is placed on the support member (that is, before the metal foil is sandwiched between the base and the support member). The effect of crystallization of the metal foil due to the heat of the base cannot be obtained.

According to the method for producing a metal foil according to the present invention, crystals having a uniform size are obtained by uniformly heating the metal foil made of an amorphous soft magnetic material without overheating the metal foil. It can be crystallized into a nano-crystalline soft magnetic material.

It is a schematic perspective view which showed the heating apparatus which carries out the manufacturing method of the metal foil which concerns on embodiment of this invention. FIG. 1 is a cross-sectional view of the heating device in the direction of arrow in line AA. FIG. 3 is a schematic perspective view showing a state in which a metal foil is brought into close contact with the heating device shown in FIG. 1. It is a figure which showed the temperature profile of the metal leaf shown in FIG. It is a schematic perspective view for demonstrating the preparation process in the manufacturing method of the metal foil which concerns on a modification. It is a schematic cross-sectional view of the metal foil manufactured by FIG. 5A. It is a schematic cross-sectional view for demonstrating the crystallization process of a metal foil using the heating apparatus shown in FIG. It is a schematic cross-sectional view for demonstrating the state of heating while adsorbing a metal foil on the installation surface of a base. It is a schematic cross-sectional view which concerns on the modification of FIG. 6B. 6 is a schematic cross-sectional view for comparison with FIG. 6B. It is a schematic perspective view for demonstrating the manufacturing process of a rotor core. It is a schematic perspective view for demonstrating the manufacturing process of a motor.

Hereinafter, a method for producing a metal leaf according to the present invention will be described with reference to the drawings. In addition, in FIGS. 1 to 4, after explaining the metal foil used, the manufacturing method in each embodiment will be described.

1. 1. About the metal foil 10 The metal foil produced in the present embodiment is a metal foil made of a nanocrystalline soft magnetic material. In the manufacturing method shown below, a metal foil made of an amorphous soft magnetic material is prepared, and the metal foil is manufactured by crystallizing the amorphous soft magnetic material into a nanocrystalline soft magnetic material by heat-treating the metal foil. do.

Here, the amorphous soft magnetic material and the nanocrystalline soft magnetic material constituting the metal foil will be described. Examples of the amorphous soft magnetic material and the nanocrystalline soft magnetic material include at least one magnetic metal selected from the group consisting of Fe, Co and Ni, and B, C, P, Al, Si, Ti and V. , Cr, Mn, Cu, Y, Zr, Nb, Mo, Hf, Ta and W, but are limited to those composed of at least one non-magnetic metal selected from the group. It's not a thing.

Typical materials of amorphous soft magnetic materials or nanocrystalline soft magnetic materials include, for example, FeCo alloys (for example, FeCo, FeCoV, etc.), FeNi alloys (for example, FeNi, FeNiMo, FeNiCr, FeNiSi, etc.), FeAl alloys. Alternatively, FeSi alloys (eg FeAl, FeAlSi, FeAlSiCr, FeAlSiTiRu, FeAlO, etc.), FeTa alloys (eg FeTa, FeTaC, FeTaN, etc.) or FeZr alloys (eg FeZrN, etc.) can be mentioned, but are limited thereto. It's not something. In the case of Fe-based alloys, Fe is preferably contained in an amount of 80 at% or more.

Further, as another material of the amorphous soft magnetic material or the nanocrystalline soft magnetic material, for example, a Co alloy containing Co and at least one of Zr, Hf, Nb, Ta, Ti and Y is used. Can be done. The Co alloy preferably contains 80 at% or more of Co. Such a Co alloy tends to become amorphous when a film is formed, and exhibits extremely excellent soft magnetism because it has few crystal magnetic anisotropy, crystal defects, and grain boundaries. Suitable amorphous soft magnetic materials include, for example, CoZr, CoZrNb, and CoZrTa alloys.

The amorphous soft magnetic material referred to in the present specification is a soft magnetic material having an amorphous structure as a main structure. In the case of the amorphous structure, no clear peak is observed in the X-ray diffraction pattern, and only a broad halo pattern is observed. On the other hand, a nanocrystal structure can be formed by applying heat treatment to an amorphous structure, but in a nanocrystal-based soft magnetic material having a nanocrystal structure, a diffraction peak is observed at a position corresponding to the lattice spacing of the crystal plane. .. From the width of the diffraction peak, the crystallite diameter can be calculated using Scherrer's equation.

In the nanocrystal-based soft magnetic material referred to in the present specification, the nanocrystal refers to a nanocrystal having a crystallite diameter of less than 1 μm calculated by Scherrer's equation from the full width at half maximum of the diffraction peak of X-ray diffraction. In the present embodiment, the crystallite diameter of the nanocrystal (the crystallite diameter calculated from the full width at half maximum of the diffraction peak of X-ray diffraction by Scherrer's equation) is preferably 100 nm or less, more preferably 50 nm or less. The crystallite diameter of the nanocrystal is preferably 5 nm or more. When the crystallite diameter of the nanocrystal is such a size, the magnetic properties are improved. The crystallite diameter of the conventional electrical steel sheet is on the order of μm, and is generally 50 μm or more.

The amorphous soft magnetic material can be obtained, for example, by melting a metal raw material blended so as to have the composition shown above at a high temperature in a high-frequency melting furnace or the like to obtain a uniform molten metal, which is rapidly cooled. Quench rate varies depending on the material, for example, about 10 ⁶ ° C. / sec, prior to crystallization, if it is possible to obtain an amorphous structure, the quench rate is not particularly limited. In the present embodiment, the metal foil described later is produced by spraying a molten metal of a metal raw material on a rotating cooling roll to produce a metal foil band made of an amorphous soft magnetic material, which is punched into a desired shape or the like. It can be obtained by molding. By quenching the molten metal in this way, a soft magnetic material having an amorphous structure can be obtained before the material crystallizes. The thickness of the metal foil is, for example, in the range of 10 μm or more and 100 μm or less, and more preferably in the range of 20 μm or more and 50 μm or less.

In the drawings described later, the metal foil 10 has a rectangular shape, but the shape is not limited to this shape. For example, the metal leaf may be a fan-shaped metal leaf according to the shape of the rotor core of the motor. The metal foil 10 is obtained from a band of an amorphous soft magnetic material by molding such as punching, and as shown in FIG. 1, the metal foil 10 is warped by such molding. There is. With respect to the metal foil 10 in which the warp is generated as described above, the metal foil 10 made of a nanocrystalline soft magnetic material can be suitably produced by the heating device 1 shown in FIG.

2. About the heating device 1 of the metal foil 10 The heating device 1 is a device for heating the metal foil 10, and sucks the base (base) 2 on which the metal foil 10 is installed and the metal foil 10 installed on the base 2. The device 3 and a plurality of heaters 5, 5, ... That heat the metal foil 10 via the base 2 are provided.

The base 2 is preferably a material having higher thermal conductivity than the heated metal foil 10, and when the metal foil 10 is an Fe-based amorphous alloy, a metal material such as an aluminum alloy or a copper alloy is preferable. The base 2 is formed with an installation surface 21 on which the metal foil 10 is installed. In the present embodiment, the installation surface 21 is flat, but the shape of the installation surface 21 is not particularly limited as long as it has a shape corresponding to the shape of the metal foil 10 to be heated.

In the present embodiment, a plurality of suction ports 22, 22, ... Are formed on the installation surface 21, and these suction ports 22, 22, ... Are communicated with each other by a suction passage 23 formed inside the base 2. is doing. A suction device 3 is connected to the other side of the suction passage 23 with respect to the suction ports 22, 22, 22, ..., Through a pipe 8. The suction device 3 may be, for example, a suction pump or the like, but may be, for example, a device that depressurizes the inside of the pipe 8 and the suction passage 23 by an asperometer (not shown) and sucks the metal foil 10.

As shown in FIG. 2, the base 2 is formed with an accommodating portion 25 accommodating each heater 5. In the present embodiment, the accommodating portion 25 is provided on the side opposite to the installation surface 21 with the suction passage 23 interposed therebetween. In the present embodiment, since the heater 5 is a rod-shaped heater 5, the accommodating portion 25 is a cavity extending in one direction, and one end thereof is open. The heater 5 is inserted into the accommodating portion 25 of the base 2 from this opened portion.

In the present embodiment, the heater 5 is an electric resistance heating type rod-shaped heater, and is connected to a power source (not shown) via a wiring 51. The heater 5 is built in the base 2. Specifically, the heater 5 is housed in the housing portion 25 of the base 2. In the present embodiment, the heater 5 is a rod-shaped heater, but the shape of the heater 5 is not particularly limited as long as the installation surface 21 of the base 2 can be uniformly heated, and the heater 5 is a planar heater. You may.

Further, in the present embodiment, the base 2 and the metal foil 10 are heated by the electric resistance of the heater 5, but the base 2 and the metal foil 10 may be heated by, for example, induction heating or heating by a heat medium. In addition to this, the heater 5 may be provided outside the base 2 to heat the base 2 from the outside.

3. 3. Method for Manufacturing Metal Foil 10 The metal foil 10 is heated by using the heating device 1 shown in FIGS. 1 and 2. First, in the present embodiment, the metal foil 10 made of an amorphous soft magnetic material is installed on the installation surface 21 of the metal base 2. At this time, the metal foil 10 is installed so as to cover the suction ports 22, 22, ... Formed on the installation surface 21.

Next, the metal foil 10 made of an amorphous soft magnetic material is brought into close contact with the base 2 so as to follow the installation surface 21. Specifically, after installing the metal foil 10, the suction device 3 is operated. As a result, the inside of the pipe 8 and the suction passage 23 are in a decompressed state, and the metal foil 10 can be sucked from the plurality of suction ports 22, 22, .... In the present embodiment, the metal foil 10 is sucked from the plurality of suction ports 22, 22 ... As shown in FIG. 3, for example, the curved metal foil 10 is made to imitate the flat installation surface 21. The shape can be corrected and the metal foil 10 can be brought into close contact with the installation surface 21 of the base 2. Further, even if foreign matter or the like is present on the installation surface 21 of the base 2, it is possible to suck the foreign matter from the suction port 22, and the foreign matter may be caught between the metal foil 10 and the base 2. Can be prevented.

Next, the amorphous soft magnetic material of the metal foil 10 is crystallized into a nanocrystalline soft magnetic material by heating the metal foil 10 in close contact with the base 2. Specifically, the installation surface is higher than the surface temperature of the metal foil 10 which is a heating temperature equal to or higher than the crystallization start temperature for crystallization into a nanocrystalline soft magnetic material and which is raised by self-heating during crystallization. The metal foil 10 is heated at a heating temperature at which the temperature of 21 is lowered. As a result, the amorphous soft magnetic material of the metal foil 10 is crystallized into a nanocrystalline soft magnetic material, and at the time of crystallization, the self-heating heat of the metal foil 10 is absorbed by the base 2.

Here, the heat treatment conditions for the metal foil 10 are not particularly limited as long as the material can be crystallized and the heat of the metal foil 10 can be absorbed by the base 2 at the time of self-heating. However, it is appropriately selected in consideration of the composition of the metal raw material and the magnetic properties to be developed. The heat treatment is preferably carried out in an atmosphere of an inert gas.

Here, the lower limit of the heating temperature for heating the metal foil 10 is the crystallization start temperature at which crystallization starts from the amorphous soft magnetic material to the nanocrystalline soft magnetic material. The "crystallization start temperature" is a temperature at which crystallization occurs in an amorphous soft magnetic material.

Since an exothermic reaction occurs during crystallization, the crystallization start temperature can be determined by measuring the temperature at which heat is generated with the crystallization of the metal foil 10. For example, differential scanning calorimetry (DSC) can be used to measure the crystallization temperature under conditions of ^{a predetermined heating rate (eg 0.67 Ks -1).} The crystallization start temperature of the amorphous soft magnetic material varies depending on the material and the like, but when the material is an Fe-based amorphous alloy, it is, for example, in the range of 400 ° C. or higher and 450 ° C. or lower.

Here, when the metal foil 10 is raised from room temperature to a temperature lower than the crystallization start temperature by the heat transferred from the installation surface 21, the amount of heat of mcΔT is retained in the metal foil 10 as sensible heat. Will be done. Here, m is the mass of the metal foil 10, c is the specific heat of the material of the metal foil 10, and ΔT is the temperature rise range. Further, a part of the heat input, ΔQout, is dissipated from the exposed surface of the metal foil 10. In addition, "Δ" described in this specification means per unit time.

Here, as shown in FIG. 4, when the metal foil 10 is heated to a crystallization start temperature Ts or higher, the metal foil 10 self-heats due to crystallization. At this time, a calorific value ΔQself is generated in the metal foil 10 due to self-heating.

For example, when the heating temperature of the base 2 (specifically, the temperature of the installation surface 21) Tt is set to the same temperature as the crystallization start temperature Ts, the metal foil 10 self-heats. Therefore, the amount of heat ΔQself generated by the self-heating of the metal foil 10 is generated, the temperature of the metal foil 10 is raised to a temperature higher than the crystallization start temperature Ts, and the rate of temperature rise of the metal foil 10 is increased.

In this case, the temperature Ta of the metal foil 10 is higher than the temperature of the installation surface 21 of the base 2 (heating temperature Tt). Therefore, although the base 2 is heated by the heater 5, the self-heated metal foil 10 serves as a heat source, and the heat generated by the self-heat is absorbed from the installation surface 21 to the base 2.

Further, even when the temperature of the installation surface 21 of the base 2 (specifically, the heating temperature Tt) is set to a temperature higher than the crystallization start temperature Ts, when the metal foil 10 reaches the crystallization start temperature Ts or higher. Since self-heating is generated from the metal foil 10, the amount of heat ΔQself generated by the self-heating of the metal foil 10 is generated.

Here, from the timing when the temperature of the metal foil 10 becomes equal to or higher than the crystallization start temperature Ts, the temperature of the metal foil 10 is further raised according to the amount of heat ΔQself due to self-heating, but the heating temperature Tt becomes self-heating. When the temperature is higher than the temperature Ta of the metal foil 10 at that time, heat continues to be input to the metal foil 10 from the installation surface 21. Therefore, in such a case, the self-heating heat of the metal foil 10 cannot be absorbed from the installation surface 21 to the base 2.

From this point of view, the upper limit of the heating temperature Tt (temperature of the installation surface 21) for heating the metal foil 10 is raised by self-heating when the metal foil 10 is placed on the base 2 and crystallized. The temperature is set lower than the temperature Ta of the metal foil 10. The upper limit of the heating temperature Tt differs depending on the material and the like, but when the material is an Fe-based amorphous alloy, for example, it is a temperature 30 ° C. to 100 ° C. higher than the above-mentioned crystallization start temperature Ts. Is preferable.

By setting the heating temperature Tt in such a range, the temperature Ta of the metal foil 10 at the time of self-heating becomes higher than the crystallization start temperature Ts, and the metal foil 10 has a heating temperature Tt equal to or higher than the crystallization temperature Ts. In the period L2 of the period L1 for heating the above, the temperature becomes higher than the heating temperature Tt. That is, in the period L1 from the time point A1 when the temperature Ta of the metal foil 10 reaches the crystallization start temperature Ts to the time point A2 when the crystallization of the metal foil 10 is completed, the temperature Ta of the metal foil 10 sets the heating temperature Tt. The period L2 from the time point A3 when the temperature exceeds the time point A3 to the time point A2 when the crystallization of the metal foil 10 is completed is a period during which the self-heated heat of the metal foil 10 is absorbed by the base 2. The time point A2 at which the crystallization of the metal foil 10 is completed is the time point at which the nanocrystals of the metal foil 10 are within the predetermined crystal grain size range.

The temperature of the metal foil 10 raised by self-heating is the amount of heat input to the metal foil 10, the amount of heat generated by the metal foil 10, the amount of heat dissipated from the surface of the metal foil 10, and the amount of heat of the metal foil 10. It can be calculated by general heat calculation from the amount of heat generated by self-heating, the amount of heat absorbed from the metal foil 10 to the installation surface 21, the contact resistance of heat between the metal foil 10 and the installation surface 21, and the like. In addition to this, the temperature of the metal foil 10 which is heated by self-heating may be experimentally obtained by actually changing the heating temperature Tt of the installation surface 21.

As described above, within the period L1 for heating the metal foil 10 at a heating temperature Tt equal to or higher than the crystallization temperature Ts, there is a period L2 in which the temperature Ta of the metal foil 10 at the time of self-heating becomes higher than the heating temperature Tt. do it. As a result, there is a period L2 in which the amount of heat absorbed from the metal foil 10 to the installation surface 21 becomes larger than the amount of heat generated by the self-heating of the metal foil 10. Therefore, in this period L2, the heat generated by the metal foil 10 is used as a base. 2 can be endothermic.

As described above, according to the present embodiment, the amorphous soft magnetic material of the metal foil 10 is crystallized into a nanocrystalline soft magnetic material by heating the metal foil 10 in a state of being in close contact with the installation surface 21 of the base 2. .. At this time, by setting the heating temperature Tt to the above-mentioned temperature, the amorphous soft magnetic material of the metal foil 10 is crystallized, and the heat of the self-heated metal foil 10 is transferred from the installation surface 21 of the base 2 to the base 2. Can absorb heat.

Since the metal foil 10 is in close contact with the base 2, the heat of the metal foil 10 is uniformly absorbed by the base 2, and the temperature of the metal foil 10 becomes uniform during crystallization. Therefore, the crystals of the metal foil 10 can be crystallized into crystals having a uniform size. As a result, it is possible to suppress a decrease in the magnetic characteristics of the metal foil 10 due to a variation in the size of the crystal grains (specifically, coarsening of the crystal grains).

In particular, in the present embodiment, since the metal foil 10 is heated by the heater 5 built in the base 2, the heater 5 built in the base 2 uniformly heats the installation surface 21 of the base 2 while heating the metal foil 10. The metal foil 10 can be uniformly heated by heat. Further, since the temperature of the installation surface 21 is lower than the temperature of the metal foil 10 that self-heats during crystallization and the temperature of the installation surface 21 is uniform, the self-heat of the metal foil 10 is transferred to the installation surface 21. The heat can be uniformly absorbed by the base 2.

Here, the metal foil 10 may be prepared in advance using the molding apparatus 20 shown in FIG. 5A. This point has been described above, but the details will be briefly described below with reference to FIG. 5A. .. In the present embodiment, the molding apparatus 20 includes a crucible 50 and a columnar cooling roll 60, and the metal foil 10 is molded by the liquid quenching method. Examples of the liquid quenching method include a single roll method, a double roll method, a centrifugal method, and the like. In the present embodiment, from the viewpoint of productivity and maintainability, a molten metal is placed on one cooling roll 60 that rotates at high speed. A single roll method is adopted in which M is supplied and rapidly cooled and solidified to obtain a strip-shaped metal foil 10A.

The crucible 50 shown in FIG. 5A is provided with a high-frequency heating heater (not shown), and the metal that is the starting material of the metal foil 10 is heated by the high-frequency heating heater to become the molten metal M. The composition of the molten metal M is as described above. Here, the crucible 50 corresponds to the above-mentioned high-frequency melting furnace.

Below the crucible 50, an injection port 51 for ejecting the molten metal M in the crucible 50 is formed. The injection port 51 has a slit-like shape and is arranged so as to face the peripheral surface of the cooling roll 60 so as to extend in the axial direction of the cooling roll 60. The cooling roll 60 is a copper roll, is connected to a motor (not shown), and is rotationally driven. Inside the cooling roll 60, a cooling mechanism through which the cooling liquid flows is provided. A pressure adjusting device (not shown) for adjusting the spraying amount (spouting amount) of the molten metal M from the injection port is provided on the upstream side of the crucible 50.

When manufacturing the metal foil 10, the molten metal M in which the material of the metal foil 10 is melted is sprayed on the peripheral surface of the rotating cooling roll 60, and the molten metal M is sprayed on the peripheral surface of the cooling roll 60. Cool and solidify. By quenching the molten metal M with the cooling roll 60, the molten metal M does not crystallize, and a strip-shaped metal foil 10 made of an amorphous soft magnetic material can be obtained. The obtained strip-shaped metal foil 10A is formed into a desired shape through cutting, punching, and the like, and the obtained metal foil 10 is heated by, for example, the heating device 1 shown in FIG.

Here, as shown in FIGS. 5A and 5B, of the surfaces of the obtained metal foil 10A (10), the surface 10a in contact with the cooling roll 60 depends on the shape of the surface of the columnar cooling roll 60. , Has a flat surface. On the other hand, among the surfaces of the obtained metal foil 10, the surface 10b opposite to the surface 10a in contact with the cooling roll 60 is uneven due to the variation in the amount of the molten metal M adhered to the cooling roll 60. .. Therefore, in the present embodiment, as shown in FIGS. 6A and 6B, the metal foil 10 is heated by using the heating device 1A.

The heating device 1A shown in FIGS. 6A and 6B is the same as the heating mechanism shown in FIGS. 1 and 2, but in the heating device 1A shown in FIGS. 6A and 6B, the installation surface 21 of the base 2 faces downward. , It is arranged upside down. The heating device 1A further includes a support member 30 at a position facing the installation surface 21 of the base 2. A moving device (not shown) for moving at least one of the base 2 and the support member 30 is attached to the base 2 and the support member 30 so that the base 2 and the support member 30 are relatively close to each other and separated from each other.

In the present embodiment, as shown in FIGS. 6A and 6B, when the metal foil 10 is brought into close contact with the base 2, the surface 10a of the surface of the metal foil 10 that is in contact with the cooling roll 60 is installed. It is brought into close contact with the surface 21. Specifically, as shown in FIG. 6A, in the present embodiment, the metal foil 10 is arranged on the support member 30 so that the surface 10a of the metal foil 10 faces the base 2. That is, the metal foil 10 is arranged on the support member 30 so that the surface 10b on the opposite side of the surface 10a of the metal foil 10 comes into contact with the support member 30.

Next, as shown in FIG. 6B, at least one of the base 2 and the support member 30 is provided with the metal foil 10 from the plurality of suction ports 22, 22, ... So that the base 2 and the support member 30 are close to each other. Move it to a position where it can be sucked. That is, in the present embodiment, the metal leaf 10 is not sandwiched between the base 2 and the support member 30. Therefore, the shape of the metal foil 10 is not corrected by the base 2 and the support member 30, but is corrected by suction of the plurality of suction ports 22, 22, ..., And the metal foil 10 is added by the base 2 and the support member 30. Without being pressed, the surface 10b on the opposite side of the metal foil 10 is exposed to the atmosphere. As a result, it is possible to prevent the metal foil 10 from being heated unevenly due to variations in the pressure distribution under pressure of the metal foil 10.

By the way, for example, as shown in FIG. 7, when the surface 10b on the opposite side of the metal foil 10 is brought into close contact with the installation surface 21 of the base 2, in the process, it is uniform, although it depends on the degree of unevenness of the surface 10b. It may not adhere to the metal (a part of it may rise). Due to the heat of the base 2, crystallization proceeds from the closely adhered portion 10c, the portion 10c contracts, and the partially non-adhered portion 10d crystallizes and shrinks due to the gap C. Due to the non-uniform shrinkage due to such crystallization, the metal foil may be plastically deformed non-uniformly. It should be noted that the portion 10d that is not in close contact with the base 2 is in close contact with the base 2 later than the portion 10c that is in close contact with the base 2.

However, of the surface of the metal foil 10, the surface 10a on the side in contact with the cooling roll 60 is flat, and as shown in FIG. 6B, the surface 10a is brought into close contact with the installation surface 21 of the base 2. The metal foil 10 can be uniformly adhered to the installation surface 21. Therefore, as compared with the case of FIG. 7, the metal foil 10 can be uniformly heated and crystallized. As a result, uniform crystallization of the metal foil 10 is promoted, and it is possible to suppress the occurrence of non-uniform plastic deformation due to strain due to shrinkage during crystallization. Therefore, the crystallized metal foil 10 can be used. It can be laminated more densely. When the heating device 1 shown in FIG. 1 is used, the surface 10a of the metal foil 10 may be arranged on the installation surface 21 of the base 2.

Further, in the crystallization step, the heating device 1B shown in FIG. 6C may be used. The base 2 of the heating device 1B is not provided with a suction port, and the base 2 has a built-in heater 5 as in FIG. 6A. Further, on at least one of the base 2 and the support member 30, the metal foil 10 is moved in a direction in which the base 2 and the support member 30 approach each other to a position where the metal foil 10 can be sandwiched between the base 2 and the support member 30. A moving device (not shown) is connected.

In the present embodiment, the metal foil 10 is placed on the support member 30, and the base 2 and the support member 30 are moved in a direction in which they are relatively close to each other, so that the metal foil 10 is moved to the base 2 and the support member 30. Put it between and. The metal foil 10 is sandwiched so that the metal foil 10 is brought into close contact with the base 2, and the metal foil 10 is heated by the heater 5 built in the base 2.

Here, as long as the metal foil 10 can be uniformly heated, the surface of the metal foil 10 that comes into contact with the base 2 may be any surface. However, when the metal foil 10 is manufactured by the above-mentioned single roll method, the surface 10a of the metal foil 10 on the side in contact with the cooling roll 60 is brought into close contact with the installation surface 21 for the same reason as described above. It is preferable to let it.

Further, in the heating device 1 shown in FIG. 1, a suction port is provided in the base 2. For example, in the heating device 1B shown in FIG. 6C, suction shown in FIG. 1 is applied to either the base 2 or the support member 30. A mouth may be provided and the metal foil 10 may be sucked. When the support member 30 is provided with a suction port, when the metal foil 10 is placed on the support member 30, the metal foil 10 can be forced to be deformed by suction of the suction port. On the other hand, when the base 2 is provided with a suction port, when the support member 30 on which the metal foil 10 is arranged is brought close to the base 2, the metal foil 10 is attracted to the installation surface 21 of the base 2 and the attracted metal foil is attracted. 10 is sandwiched between the support members 30 and pressurized.

Here, among the metal foils 10, the surface of the metal foil 10 that comes into contact with the base 2 is the heating device shown in FIG. 6C when the shape of the metal foil 10 is slightly warped or undulated regardless of the surface. When the metal foil 10 is heated in 1B, the metal foil 10 may be heated unevenly. In view of these points, the inventors have found the following points, as is clear from the experiments described later.

Specifically, when the heating device 1B shown in FIG. 6C is used in the crystallization step, it is preferable to satisfy the following conditions (i) or (ii).
(I) The thermal conductivity of the material constituting the support member 30 is 0.2 W / mK or less.
(Ii) The temperature of the support member 30 is set to 300 ° C. or higher and lower than the crystallization start temperature.

The metal foil 10 is heated by the heater 5 built in the base 2 while being sandwiched between the base 2 and the support member 30, and the metal foil 10 crystallizes. (I) The material constituting the support member 30. By setting the thermal conductivity of the above to 0.2 W / mK or less, heat is not easily taken away by the support member 30.

Specifically, the temperature of the installation surface 21 of the base 2 when the metal foil 10 is in close contact with the metal foil 10 due to the wavy shape (wavy shape) and the warped shape of the metal foil 10 generated by punching or cutting. Even if the distribution is biased, the heat of the metal foil 10 is less likely to be taken away by the support member 30. As a result, heat is easily retained between the metal foil 10 and the support member 30, so that the temperature distribution of the metal foil 10 can be made uniform.

As a result, it is possible to suppress a local temperature drop of the installation surface 21 of the base 2 while the metal foil 10 is in close contact with the base 2. As a result, uniform crystallization of the metal foil 10 is promoted, and it is possible to suppress the occurrence of non-uniform plastic deformation due to strain due to shrinkage during crystallization. Therefore, the crystallized metal foil 10 can be used. It can be laminated more densely.

Here, as is clear from the examples described later, when the thermal conductivity of the material constituting the support member 30 exceeds 0.2 W / mK, the heat of the installation surface 21 of the base 2 becomes metal. It is easy to escape to the support member via the foil. Therefore, even if the temperature distribution of the installation surface 21 of the base 2 is biased when the metal foil 10 is in close contact with the metal foil 10, it is difficult for the bias to become uniform, and the crystallization of the metal foil 10 starts from a high temperature portion. Therefore, the timing of contraction due to crystallization differs depending on the site. As a result, non-uniform plastic deformation of the metal foil 10 occurs, and the crystallized metal foil 10 may not be densely laminated.

Here, as a material constituting the support member 30, as a material satisfying the condition of thermal conductivity of 0.2 W / mK or less, calcium silicate, gypsum, or a resin such as PVC or acrylic can be mentioned. Can be done.

On the other hand, when the metal foil 10 is crystallized by being heated by the heater 5 built in the base 2, (ii) the temperature of the support member 30 is set to 300 ° C. or higher and lower than the crystallization start temperature of the metal foil. Since the temperature difference between the base 2 and the support member 30 is small, the heat of the base is not easily taken away by the support member.

Specifically, even if the temperature distribution of the installation surface 21 of the base 2 is biased when the metal foil 10 is brought into close contact with the metal foil 10 due to the shape of the metal foil 10 such as warpage, the heat of the metal foil 10 is generated. It is difficult for the support member 30 to take away, and the temperature distribution of the metal foil 10 can be made uniform.

As a result, it is possible to suppress a local temperature drop of the installation surface 21 of the base 2 while the metal foil 10 is in close contact with the base 2. As a result, uniform crystallization of the metal foil 10 is promoted, and it is possible to suppress the occurrence of non-uniform plastic deformation due to strain due to shrinkage during crystallization. Therefore, the crystallized metal foil 10 can be used. It can be laminated more densely.

Here, as is clear from the examples described later, when the temperature of the support member 30 is less than 300 ° C., the heat of the installation surface 21 of the base 2 easily escapes to the support member 30 via the metal foil 10. .. Therefore, when the temperature of the installation surface 21 varies, the progress of crystallization of the metal foil 10 differs depending on the site according to the temperature variation, so that the timing of shrinkage due to crystallization differs depending on the site. It ends up. As a result, non-uniform plastic deformation occurs in the metal foil 10, and the crystallized metal foil 10 may not be densely laminated. On the other hand, when the temperature of the support member 30 is equal to or higher than the crystallization start temperature of the metal foil 10, when the metal foil 10 is arranged on the support member 30 (that is, before the metal foil is sandwiched between the base 2 and the support member 30). ), The metal foil 10 may crystallize, and the effect of crystallizing the metal foil 10 by the heat of the base 2 cannot be obtained.

When the heating device 1B shown in FIG. 6C is used in the crystallization step, it is more preferable to further satisfy the following conditions. Specifically, in the crystallization step, the metal foil 10 is moved in the direction in which the base 2 and the support member 30 approach each other at a moving speed of 125 mm / sec or more and at least one of the base 2 and the support member 30 is moved. Is sandwiched between the base 2 and the support member 30. As a result, the metal foil 10 can be brought into contact with the installation surface 21 of the base 2 in an instant, and the timing of heating to the installation surface 21 of the base 2 can be brought closer to each portion of the metal foil 10. As a result, since the metal foil 10 can be heated more uniformly, uniform crystallization of the metal foil 10 is promoted, and non-uniform plastic deformation due to shrinkage during crystallization can be suppressed. Therefore, the crystallized metal foil 10 can be laminated more precisely.

Here, when the moving speed between the base 2 and the support member 30 is less than 125 mm / sec, there is a portion where heating is locally started in contact with the base 2 as compared with other portions. In some cases, the timing of contraction associated with crystallization may differ from site to site. As a result, non-uniform plastic deformation occurs in the metal foil 10, and the crystallized metal foil 10 may not be densely laminated.

In the present embodiment, the rectangular metal foil 10 is manufactured. For example, in the case of manufacturing the stator of the motor, a fan-shaped metal foil in which the stator core is divided in the circumferential direction around the rotation axis of the motor is prepared. By heating this, a metal foil made of a nanocrystalline soft magnetic material is produced. Next, the metal foils 10 are brought into close contact with each other at a predetermined pressure to form the laminated body 10A. At this time, the metal foils 10 may be restrained by a resin such as an adhesive.

Further, as shown in FIG. 8A, the stator core 80A is manufactured by stacking the laminated body 10A in the state of the stator core and fixing the laminated body 10A. In FIGS. 8A and 8B, detailed shapes such as teeth of the stator core are omitted.

Finally, as shown in FIG. 8B, an assembly step is performed. In this step, a coil (not shown) is arranged on the teeth (not shown) of the stator core to form a stator 80, and the stator 80 and the rotor 70 are arranged in a case (not shown) so that the motor 100 can be formed. Manufactured.

Hereinafter, the method for producing a metal foil according to the present embodiment will be described in more detail with reference to Examples and Comparative Examples.

[Example 1]
First, a metal leaf (NANOMET manufactured by Tohoku Magnet Institute Co., Ltd.) made of an amorphous soft magnetic material (Fe-based amorphous alloy) having a thickness of 25 μm, which was produced by a general method, was prepared. The crystallization start temperature of this metal foil is 419.19 ° C. This metal leaf was brought into close contact with the surface of a hot plate heated to 500 ° C. for 1 second. That is, the heating temperature of the metal foil is 500 ° C. The obtained metal foil was crystallized into a nanocrystalline soft magnetic material, and the saturation magnetic flux density was in the range of 1.76 to 1.73 T, and the coercive force was in the range of 8 to 10 A / m.

[Comparative Example 1]
A metal leaf was produced in the same manner as in Example 1. The difference from the first embodiment is that the metal foil is heated without sucking the metal foil in a state where a part of the metal foil is not in contact with the hot plate. The obtained metal foil was crystallized into a nanocrystalline soft magnetic material, but the portion of the metal foil that was not in contact with the hot plate was overheated, and it was confirmed that the crystals were coarsened. The saturation magnetic flux density was 1.74 T and the coercive force was 3751 A / m. It can be said that when a metal foil having this characteristic is motorized, the torque loss becomes large.

As described above, in the case of Comparative Example 1, it is considered that the portion of the metal foil not in contact with the hot plate was heated to about 800 ° C. due to the self-heating of the metal foil. As a result, it is considered that fine crystals could not be obtained as in the metal foil of Example 1, and the coercive force was higher than that of Example 1.

[Example 2-1]
The metal leaf was heated in the same manner as in Example 1. Specifically, first, an amorphous soft magnetic material having a thickness of 25 μm (Fe-based amorphous alloy, specifically, Fe—Ni—B-based amorphous alloy) is strip-shaped using the molding apparatus 20 shown in FIG. 5A. The metal leaf 10A of the above was manufactured. From the obtained strip-shaped metal foil 10A, a plurality of ring-shaped metal foils 10 having an outer diameter of 50.4 mm and an inner diameter of 30 mm were punched and molded. Next, as shown in FIG. 6B, the metal foil 10 was heated while the surface 10a of the metal foil 10 on the side in contact with the cooling roll 60 was brought into close contact with the installation surface 21 of the base 2 heated to 500 ° C. A plurality of metal foils 10 made of a soft magnetic material were manufactured. A laminated body in which 400 sheets of the metal foil 10 were laminated was produced. The dimension in the layer thickness direction of the laminate is measured as the thickness of the laminate, and the measured thickness of the laminate is divided by the thickness of the laminate when the density is 100% and multiplied by 100. Was calculated as the space factor of the laminated body. The results are shown in Table 1.

[Example 2-2]
A laminate was produced in the same manner as in Example 2-1. The difference from Example 2-1 is that the metal foil 10 is heated by the heating device 1B as shown in FIG. 6C. In Example 2-2, the steel support member 30 is provided with a plurality of suction ports, and the metal foil 10 is sucked to correct the shape of the metal foil 10 and the metal foil 10 is used as a base with the support member 30. I put it between 2 and 2. The space factor of the obtained laminate was calculated in the same manner as in Example 2-1. The results are shown in Table 1. In Example 2-2, the metal foil 10 was heated while the surface 10a of the metal foil 10 on the side in contact with the cooling roll 60 was brought into close contact with the installation surface 21 of the base 2.

[Example 2-3]
A laminate was produced in the same manner as in Example 2-1. The difference from Example 2-1 is that, as shown in FIG. 7, the metal foil is brought into close contact with the installation surface 21 of the base 2 while the surface 10b of the metal foil 10 on the side not in contact with the cooling roll 60 is in close contact with the installation surface 21. It is a point where 10 is heated. The space factor of the obtained laminate was calculated in the same manner as in Example 2-1. The results are shown in Table 1.

[Example 2-4]
A laminate was produced in the same manner as in Example 2-2. The difference from the second embodiment is that the surface 10b of the metal foil 10 on the side not in contact with the cooling roll 60 is brought into close contact with the installation surface 21 of the base 2 by the heating device 1B shown in FIG. 6C. This is the point where the foil 10 is heated. The space factor of the obtained laminate was calculated in the same manner as in Example 2-1. The results are shown in Table 1.

In the order of Examples 2-1 to 2-4, the space factor of the laminated body decreased. The space factor of the laminate of Example 2-1 was the highest because the surface 10a on the side in contact with the cooling roll 60 was flat and the surface 10a was uniformly adhered to the base 2 which is a heat source. It is thought that there is. In addition to this, in Example 2-1 the surface 10b on the side not in contact with the cooling roll 60 is exposed to the atmosphere without coming into contact with a material having a higher thermal conductivity than the atmosphere, such as a support member. Therefore, it is considered that the heat from the base 2 is uniformly transferred to the metal foil 10.

The space factor of the laminate of Example 2-2 is lower than that of Example 2-1 because the metal foil 10 is sandwiched between the base 2 and the support member 30, so that the heat from the base 2 is metal. It is probable that the heat was locally escaped to the support member 30 via the foil 10 and the heat transfer to the metal foil 10 became non-uniform.

Further, in the case of Examples 2-3 and 2-4, the surface (surface having irregularities) 10b of the metal foil 10 on the side not in contact with the cooling roll 60 comes into contact with the base 2 which is a heat source. It is probable that the heat transfer to the metal foil 10 became non-uniform. It is considered that the non-uniform heat transfer caused the metal foil 10 to be distorted and plastically deformed during crystallization, resulting in a decrease in the space coefficient of the laminated body.

[Example 3-1]
A laminate was produced in the same manner as in Example 2-1. In Example 3-1 the metal leaf 10 was heated by the heating device 1B shown in FIG. 6C. Specifically, the base 2 is brought close to the support member 30 so that the relative moving speed between the base 2 and the support member 30 of the heating device 1B shown in FIG. 6C is 125 mm / sec, and the metal foil 10 is formed by these. Was sandwiched. The temperature of the support member 30 was set to room temperature (within the range of 20 ° C. to 50 ° C.), and a material having a thermal conductivity of 0.2 W / mK made of calcium silicate was used for the support member 30. The appearance of the metal foil 10 obtained by heating was confirmed, and the space factor of the obtained laminate was calculated in the same manner as in Example 2-1. The results are shown in Table 2.

[Example 3-2]
A laminate was produced in the same manner as in Example 3-1. The difference from Example 3-1 is that the base 2 is brought closer to the support member 30 so that the relative moving speed between the base 2 and the support member 30 of the heating device 1B shown in FIG. 6C is 128 mm / sec. , The point where the metal foil 10 is sandwiched between them. Further, the difference is that the support member 30 is made of a material having a thermal conductivity of 0.4 W / mK composed of glass fiber and cement. The appearance of the metal foil 10 obtained by heating was confirmed, and the space factor of the obtained laminate was calculated in the same manner as in Example 2-1. The results are shown in Table 2.

[Example 3-3]
A laminate was produced in the same manner as in Example 3-1. The difference from Example 3-1 is that the base 2 is brought closer to the support member 30 so that the relative moving speed between the base 2 and the support member 30 of the heating device 1B shown in FIG. 6C is 128 mm / sec. , The point where the metal foil 10 is sandwiched between them. Further, the difference is that the support member 30 is made of a rolled steel material for general structure (JIS standard: SS400) and has a thermal conductivity of 51.6 W / mK. The appearance of the metal leaf 10 obtained by heating was confirmed. The results are shown in Table 2.

[Examples 3-4 to 3-7]
A laminate was produced in the same manner as in Example 3-3. The difference between Examples 3-4 to 3-7 is that the relative moving speed between the base 2 of the heating device 1B and the support member 30 shown in FIG. 6C is 136 mm / sec. The base 2 is brought close to the support member 30 so as to be 131 mm / sec, 129 mm / sec, and 136 mm / sec, and the metal foil 10 is sandwiched between them. Further, the difference is that the temperature of the support member 30 on which the metal foil 10 is arranged is set to 100 ° C., 200 ° C., 300 ° C., and 400 ° C. The appearance of the metal leaf 10 obtained by heating was confirmed. The results are shown in Table 2. The space factor of the laminates of Examples 3-5 and 3-6 was calculated in the same manner as in Example 2-1 and is shown in Table 2.

As is clear from Table 2, when Examples 3-1 to 3-3 are compared, the metal foil 10 of Example 3-1 has no wrinkles, and the laminate of Example 3-1 is occupied. The product ratio was higher than that of Example 3-2. This is because the thermal conductivity of the support member 30 is significantly different between Examples 3-1 to 3-3. If the support member 30 made of a material having a low thermal conductivity (0.2 W / mK or less) is used as in Example 3-1 the heat of the metal foil 10 is hard to escape locally to the support member 30, and the metal It is considered that the foil 10 can be heated uniformly and plastic deformation is unlikely to occur when the metal foil 10 is crystallized.

As is clear from Table 2, when Examples 3-3 to 3-7 are compared, the metal foils 10 of Examples 3-6 and 3-7 have no wrinkles, and Example 3- The space factor of the laminated body of No. 6 was higher than that of Example 3-5. This is because the temperatures of the support members 30 differ greatly between Examples 3-3 to 3-7. If the temperature of the support member 30 is set to 300 ° C. or higher as in Examples 3-6 and 3-7, the temperature of the support member 30 is brought closer to the temperature of the base 2, and the heat of the metal foil 10 is locally applied to the support member 30. It is considered that the metal foil 10 is hard to escape to the surface, the metal foil 10 can be heated uniformly, and plastic deformation is unlikely to occur when the metal foil 10 is crystallized.

[Examples 4-1 to 4-4]
A laminate was produced in the same manner as in Example 3-1. The difference between Examples 4-1 and 4-4 from Example 3-1 is that the relative moving speeds of the base 2 and the support member 30 of the heating device 1B shown in FIG. 6C are sequentially set to 21 mm. The point is that the base 2 is brought close to the support member 30 and the metal foil 10 is sandwiched between the base 2 so as to be / sec, 86 mm / sec, 125 mm / sec, and 513 mm / sec. In addition, Example 4-3 is the same as Example 3-1. The appearance of the metal leaf 10 obtained by heating was confirmed. The results are shown in Table 3. Table 3 also shows the space factor of the laminates of Examples 4-2 and 4-3.

As is clear from Table 3, when Examples 4-1 to 4-4 are compared, the metal foils 10 of Examples 4-3 and 4-4 have no wrinkles, and that of Example 4-3 The space factor of the laminated body was higher than that of Example 4-2. This is because the moving speeds of the support members 30 differ greatly between Examples 4-1 to 4-4. By setting the moving speed to 125 mm / sec or more as in Examples 4-3 and 4-4, the metal foil 10 is instantly sandwiched between the base 2 and the support member 30, and the metal foil 10 is made uniform. It can be heated, and it is considered that plastic deformation is unlikely to occur when the metal foil 10 is crystallized.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs are designed without departing from the spirit of the present invention described in the claims. You can make changes.

In the present embodiment, the stator core of the motor is manufactured by laminating a metal foil made of a nanocrystalline soft magnetic material, but the rotor core of the motor may be manufactured by laminating the metal foil.

In the present embodiment, the installation surface of the base is directed upward. For example, the installation surface of the base is directed downward, the installation surface is brought close to the metal foil from above the metal foil, the metal foil is adsorbed, and the metal foil is conveyed together with the base. While heating the metal foil, the metal foil may be heated.

In the present embodiment, the temperature (heating temperature) of the installation surface of the base is kept constant, but for example, when the metal foil self-heats, the heating of the heater is stopped to lower the temperature of the installation surface. good.

10: Metal foil, 2: Base, 21: Installation surface ,: 22: Suction port, 5: Heater, Ta: Metal foil temperature, Ts: Crystallization start temperature, Tt: Heating temperature

Claims (5)

A manufacturing method for manufacturing a metal foil made of a nanocrystalline soft magnetic material.
The manufacturing method includes a step of preparing a metal foil made of an amorphous soft magnetic material and a process of preparing a metal foil.
By heating the metal foil while keeping the metal foil in close contact with the base so that the prepared metal foil imitates the installation surface of the metal base, the amorphous soft magnetic material of the metal foil is made into the nano. Including the step of crystallizing into a crystalline soft magnetic material,
In the crystallization step, the heating temperature is equal to or higher than the crystallization start temperature at which the nanocrystalline soft magnetic material is crystallized, and the temperature is higher than the temperature of the metal foil which is raised by self-heating during crystallization. By heating the metal foil at a heating temperature at which the temperature of the installation surface becomes low, the amorphous soft magnetic material is crystallized, and the heat of self-heating at the time of crystallization is absorbed by the base. A method for producing a metal foil, which is characterized by. The method for producing a metal foil according to claim 1, wherein in the crystallization step, the metal foil is heated by a heater built in the base. In the crystallization step, when the metal foil is brought into close contact with the base, the metal foil is sucked from a suction port formed on the base to bring the metal foil into close contact with the base. The method for producing a metal foil according to claim 1 or 2. In the step of preparing the metal foil, the molten metal obtained by melting the material of the metal foil is sprayed onto a rotating roll, and the molten metal is cooled and solidified on the roll to solidify the amorphous soft material. Manufacture the metal foil made of magnetic material,
3. The method for producing a metal foil according to item 1. In the process of preparing the metal foil, as the metal foil, a metal foil made of an iron-based amorphous soft magnetic material is prepared.
In the crystallization step, the metal foil is placed on the support member, and at least one of the base and the support member is moved in a direction in which the base and the support member approach each other. The metal foil is sandwiched between the base and the support member, and the metal foil is heated by a heater built in the base while the metal foil is brought into close contact with the base.
The method for producing a metal foil according to any one of claims 1 to 4, wherein in the crystallization step, the following conditions (i) or (ii) are satisfied.
(I) The thermal conductivity of the material constituting the support member is 0.2 W / mK or less.
(Ii) The temperature of the support member is set to 300 ° C. or higher and lower than the crystallization start temperature.

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