JP2020117746A - Manufacturing method of alloy ribbon - Google Patents

Abstract

To provide a manufacturing method of an alloy ribbon capable of suppressing coarsening of a crystal grain and precipitation of a compound phase.SOLUTION: The manufacturing method of an alloy ribbon according to the present invention comprises a preparatory step of preparing a laminate in which a plurality of amorphous alloy ribbons are laminated, a first heat treatment step of heating the laminate to a first temperature range below a crystallization start temperature of the amorphous alloy ribbons, a second heat treatment step of heating an end portion of the laminate in a plane direction to a second temperature range of the crystallization start temperature or higher after the first heat treatment step, and a heat radiating step of applying a heat radiating gas to an end face opposite in the plane direction to the end portion of the laminate.SELECTED DRAWING: Figure 2

Description

The present invention relates to a method for producing an alloy ribbon obtained by crystallizing an amorphous alloy ribbon.

Conventionally, since the amorphous alloy ribbon is a soft magnetic material, a laminated body of the amorphous alloy ribbon has been used as a core in a motor, a transformer or the like. Since the nanocrystalline alloy ribbons crystallized by heating the amorphous alloy ribbons are soft magnetic materials capable of achieving both a high saturation magnetic flux density and a low coercive force, in recent years, a stack of nanocrystalline alloy ribbons has been formed. The body is used as their core.

When the amorphous alloy ribbon is crystallized to obtain the nanocrystalline alloy ribbon, heat is released by the crystallization reaction, which may cause an excessive temperature rise. As a result, the soft magnetic properties may be deteriorated due to coarsening of crystal grains and precipitation of a compound phase.

In order to deal with such a problem, by heating and crystallizing the amorphous alloy ribbons one by one independently, the heat dissipation is improved and the temperature rise due to the release of heat by the crystallization reaction is increased. A method of reducing the influence can be used, but the productivity is low because the heat treatment is performed one by one.

Therefore, for example, in Patent Document 1, in a method in which a laminated body of amorphous alloy ribbons is sandwiched by plates from both ends in the laminating direction and the plates are heated from both ends to be crystallized, a crystallization reaction A method has been proposed in which the temperature rise is suppressed by absorbing the released heat in the plates at both ends.

Further, Patent Document 2 describes a method of adjusting the temperature distribution in the laminate during heating by heating the laminate by sandwiching a heater between adjacent amorphous alloy ribbons.

JP, 2017-141508, A JP, 2011-165701, A

However, in the method proposed in Patent Document 1, since the reaction heat of the plurality of amorphous alloy ribbons is absorbed by the plate from both ends in the stacking direction, the thickness of the stacked body (the number of stacked layers) is a thickness that can be absorbed by the plate. Due to this limitation, there is a limit to the number of alloy ribbons that can be crystallized by heat treatment to one laminated body, and it is possible to produce alloy ribbons obtained by crystallizing an amorphous alloy ribbon with high productivity. Can not. The same is true even if the method proposed in Patent Document 2 is applied.

Therefore, in order to produce an alloy ribbon obtained by crystallizing an amorphous alloy ribbon with high productivity, a laminated body in which a plurality of amorphous alloy ribbons are stacked is placed in a temperature range below the crystallization start temperature of the amorphous alloy ribbon. After soaking, only by heating the end portion in the plane direction of the laminate to a temperature range equal to or higher than the crystallization start temperature, the crystallization reaction in the laminate is caused to propagate in the plane direction, and the entire laminate It is proposed to use a method of crystallizing. Further, in this method, in the portion near the end face on the side opposite to the end face in the plane direction in the laminated body, thermal accumulation due to the heat released from the crystallization reaction causes coarsening of crystal grains and compound phase. In order to suppress the occurrence of precipitation of the laminated body, after heating the end portion of the laminated body, a heat dissipation member is applied to the end surface of the laminated body opposite to the end portion in the plane direction to dissipate the heat from the end surface. It is proposed to apply the method.

However, in the method of dissipating heat in this way, there is variation in the plane dimension of the amorphous alloy ribbon in the laminate, and the end face on the opposite side in the plane direction from the end portion in the laminate is caused. Even if the heat radiating member is applied, the heat radiating member cannot be applied to the end faces of all the alloy ribbons, so that heat may not be dissipated from the end faces of all the alloy ribbons. For this reason, it may not be possible to suppress coarsening of crystal grains and precipitation of a compound phase in a portion near the end surface of the alloy ribbon in which heat cannot be dissipated.

The present invention has been made in view of such a point, and the purpose thereof is to provide a method for producing an alloy ribbon in which an amorphous alloy ribbon is crystallized, in which a crystal grain is coarsened or a compound phase is precipitated. It is an object of the present invention to provide a method for manufacturing an alloy ribbon that can suppress the above.

In order to solve the above-mentioned problems, the method for producing an alloy ribbon according to the present invention includes a preparatory step of preparing a laminated body in which a plurality of amorphous alloy ribbons are laminated, the laminated body being a crystal of the amorphous alloy ribbon. A first heat treatment step of heating to a first temperature range lower than the crystallization start temperature, and a step of heating the end portion in the plane direction of the laminate to a second temperature range of the crystallization start temperature or higher after the first heat treatment step. A heat treatment step of applying a heat-releasing gas to an end surface of the laminated body opposite to the end portion in the plane direction, the laminated body being subjected to the second heat treatment step after the first heat treatment step. In the first heat treatment step, the ambient temperature around the laminated body is maintained so that the laminated body is maintained in a temperature range in which crystallization is possible by heating the end portion of the laminated body to the second temperature range. The amount of heat required to heat the laminate to the first temperature range is Q1, and the heat is applied to the laminate when the end portion of the laminate is heated to the second temperature range in the second heat treatment step. When the amount of heat is Q2, the amount of heat released when the laminate is crystallized is Q3, and the amount of heat required to bring the entire laminate to the crystallization start temperature is Q4, the following formula (1 ) Is satisfied.

Q1+Q2+Q3≧Q4 (1)

In addition, in the method for producing an alloy ribbon according to the present invention, usually, in order to crystallize the entire laminated body by using the amount of heat released when the laminated body is crystallized, the amount of heat given from outside (Q1 and The sum of Q2) does not exceed the amount of heat (Q4) required to bring the entire laminated body to the crystallization start temperature, and satisfies the following formula (2).

Q1+Q2<Q4 (2)

According to the present invention, coarsening of crystal grains and precipitation of a compound phase can be suppressed in a method for producing an alloy ribbon in which an amorphous alloy ribbon is crystallized.

It is a schematic process drawing which shows an example of the manufacturing method of the alloy ribbon which concerns on this embodiment. It is a schematic process drawing which shows an example of the manufacturing method of the alloy ribbon which concerns on this embodiment. It is a graph which shows typically the temperature profile of each part in each amorphous alloy ribbon of the laminated body in the manufacturing method of the alloy ribbon shown in FIG. 1 and FIG. It is a schematic process drawing of the manufacturing method of the alloy ribbon of a prior art, and is a figure corresponding to the schematic process drawing shown in FIG.2(d). It is a schematic process drawing which shows the 2nd heat treatment process and heat dissipation process in the other example of the manufacturing method of the alloy ribbon which concerns on this embodiment. It is a schematic process drawing which shows the 2nd heat treatment process and heat dissipation process in the other example of the manufacturing method of the alloy ribbon which concerns on this embodiment. It is a figure which shows the temperature of each position of the calculation model of a laminated body in an image 52 seconds after heating the outer peripheral side edge part in the plane direction in an Example with an image. It is a figure which shows the temperature of each position of the calculation model of a laminated body in an image for 20 seconds and 52 seconds after heating the outer peripheral side edge part in the plane direction in a comparative example with an image.

Hereinafter, an embodiment of a method for manufacturing an alloy ribbon according to the present invention will be described.

The method for manufacturing an alloy ribbon according to the present embodiment, a preparatory step of preparing a laminated body in which a plurality of amorphous alloy ribbons are laminated, the laminate, a first temperature below the crystallization start temperature of the amorphous alloy ribbon. A first heat treatment step of heating to one temperature range, a second heat treatment step of heating the end portion of the laminate in the plane direction to a second temperature range equal to or higher than the crystallization start temperature after the first heat treatment step, A heat-dissipating step of applying a heat-dissipating gas to an end surface opposite to the end portion of the laminate in the plane direction, and the end portion of the laminate is formed by the second heat treatment step after the first heat treatment step. The ambient temperature around the laminated body is maintained so that the laminated body is maintained in a temperature range where it can be crystallized by heating to the second temperature range, and the laminated body is subjected to the first heat treatment step in the first heat treatment step. The amount of heat required to heat the laminate to 1 temperature range is Q1, and the amount of heat given to the laminate when heating the end of the laminate to the second temperature range in the second heat treatment step is Q2. When the amount of heat released when the laminated body is crystallized is Q3 and the amount of heat required to bring the entire laminated body to the crystallization start temperature is Q4, the following formula (1) is satisfied. And In the present embodiment, the “planar direction” means the direction perpendicular to the stacking direction of the stacked body.

Q1+Q2+Q3≧Q4 (1)

First, an example of the method for manufacturing the alloy ribbon according to the present embodiment will be described.
Here, FIG. 1A to FIG. 2D are schematic process diagrams showing an example of the method for manufacturing the alloy ribbon according to the present embodiment. In the schematic process diagram of FIG. The states of the second heat treatment step and the heat radiation step in the above are shown. FIG. 3 is a graph schematically showing a temperature profile of each part in each amorphous alloy ribbon of the laminated body in the method for manufacturing the alloy ribbon shown in FIGS. 1 and 2. The graph of FIG. 3 shows the temperature profile of the central position of each part including the first, second, and third parts which are sequentially separated from one end face in the plane direction of each amorphous alloy ribbon to the opposite end face side. Partially omitted.

In the example of the present embodiment, first, in a preparation step, as shown in FIG. 1A, a laminated body 10 in which a plurality of amorphous alloy ribbons 2 are laminated is prepared.

Next, in the first heat treatment step, as shown in FIG. 1B, the laminated body 10 is moved into the heating furnace 20, and in the heating furnace 20, the first temperature below the crystallization start temperature of the amorphous alloy ribbon 2 is obtained. Heat to 1 temperature range. Specifically, for example, as shown in the temperature profile of FIG. 3, the entire laminated body 10 is evened so that the entire temperature of all the amorphous alloy ribbons 2 in the laminated body 10 falls within the first temperature range. heat.

Next, in the second heat treatment step, as shown in FIG. 2C, the high temperature heat source 30 is moved into the heating furnace 20, and as shown in FIG. The radiant heat of the high temperature heat source 30 is applied to the one end face 10As. As a result, as shown in the temperature profile of FIG. 3, in all the amorphous alloy ribbons 2 of the laminated body 10, the portions other than the end portion 2A which is the first portion from the one end face in the plane direction start to be crystallized. While maintaining the temperature range below the temperature, one end 2A in the plane direction is heated to the second temperature range above the crystallization start temperature.

Further, in the heat dissipation step, after the end portions 2A of all the amorphous alloy ribbons 2 are heated to the second temperature range in the second heat treatment step, they are installed in the heating furnace 20 as shown in FIG. 2(d). By the rotation of the fan 40, the outside air taken into the heating furnace 20 from the air supply port 41 is sent toward the end surface 10Zs on the opposite side to the one end surface 10As in the plane direction of the laminated body 10, and the heating furnace 20 The air inside is exhausted from the exhaust port 42. As a result, forced convection of the heat radiating gas 50 is generated, and the heat radiating gas 50 of forced convection is applied to the end surface 10Zs of the laminated body 10 on the opposite side in the plane direction.

Then, in an example according to the present embodiment, after the first heat treatment step, one end 2A in the plane direction of all the amorphous alloy ribbons 2 is crystallized by heating to the second temperature range in the second heat treatment step. The ambient temperature around the laminated body 10 is maintained so that the entire laminated body 10 is maintained in a possible temperature range. In other words, after the first heat treatment step, in the second heat treatment step, one end 2A in the plane direction of all of the amorphous alloy ribbons 2 is heated to the second temperature range to crystallize the entire laminated body 10. The ambient temperature around the laminated body 10 is maintained so that the entire laminated body 10 is maintained in a temperature range in which the above may occur.

Further, the amount of heat required to heat the entire laminated body 10 to the first temperature range in the first heat treatment step is Q1, and one end 2A in the plane direction of all the amorphous alloy ribbons 2 in the second heat treatment step. In order to bring the entire laminated body 10 to the crystallization start temperature, let Q2 be the amount of heat given to the laminated body 10 when heating the laminated body 10 to the second temperature range, and let Q3 be the amount of heat released when the laminated body 10 is crystallized. When the required amount of heat is Q4, the following formula (1) is satisfied.

Q1+Q2+Q3≧Q4 (1)

According to the example of the present embodiment, one end 2A in the plane direction of all the amorphous alloy ribbons 2 is heated to the second temperature range equal to or higher than the crystallization start temperature by the second heat treatment step as described above. By doing so, as shown in FIG. 2D, the end 2A is crystallized. At this time, the end portion 2A releases heat due to the crystallization reaction. In all the amorphous alloy ribbons 2, the released heat moves from the end portion 2A having a high temperature after the crystallization reaction to the second portion 2B from the one end surface in the plane direction where the temperature is low. Then, as described above, since the ambient temperature around the laminated body 10 is maintained and the above expression (1) is satisfied, the second portion 2B is mainly heated by the emitted heat, As shown in the temperature profile of FIG. 3, it is in the second temperature range. As a result, the second portion 2B crystallizes and releases heat due to the crystallization reaction, as shown in FIG. 2(d). Similarly, the third portion 2C from the one end face in the plane direction of all the amorphous alloy ribbons 2 is heated mainly by the emitted heat, so that the second temperature as shown in the temperature profile of FIG. It becomes an area. As a result, the third portion 2C crystallizes and releases heat due to the crystallization reaction, as shown in FIG. 2(d).

As shown in FIG. 2D, the crystallization reaction and the heat release due to the crystallization reaction occur in all the amorphous alloy ribbons 2 from one end portion 2A in the plane direction to the other end portion in the plane direction. Repeatedly propagates up to 2Z. Therefore, after heating the laminated body 10 to the first temperature range in the first heat treatment step, one end 2A in the plane direction of all the amorphous alloy ribbons 2 is heated to the second temperature range in the second heat treatment step. Only by itself, all the amorphous alloy ribbons 2 of the laminated body 10 can be crystallized to produce a nanocrystalline alloy ribbon. At this time, the thickness of the laminated body 10 (the number of laminated layers) is not particularly limited.

Further, according to the example of the present embodiment, as described above, in the heat dissipation step, the forced convection heat dissipation gas 50 is applied to the end surface 10Zs of the laminated body 10 on the opposite side in the plane direction, whereby the crystal grains become coarse. Formation and the precipitation of the compound phase can be suppressed. Hereinafter, this will be described in detail.

Here, the difference between the conventional method for producing an alloy ribbon and the example according to the present embodiment will be described. FIG. 4 is a schematic process diagram of a conventional method for manufacturing an alloy ribbon, and is a diagram corresponding to the schematic process diagram shown in FIG.

In the conventional method for manufacturing an alloy ribbon, as shown in FIG. 4, in the heat dissipation step, the heat dissipation member 60 is not the forced convection heat dissipation gas but the end surface 10Zs on the opposite side in the plane direction of the laminate 10. Hit In this case, as shown in FIG. 4, the dimension of the amorphous alloy ribbon 2 in the laminated body 10 in the plane direction varies, and the heat dissipation member 60 is arranged in the plane of all the amorphous alloy ribbons 2. Since the end surface 2Zs on the side opposite to the one end 2A in the direction cannot be applied to the end surface 2Zs, heat may not be dissipated from the end surface 2Zs on the side opposite to the plane direction of all the amorphous alloy ribbons 2.

Therefore, according to the method for manufacturing an alloy ribbon of the prior art, in the portion near the end surface 2Zs on the opposite side in the plane direction of the amorphous alloy ribbon 2 where heat cannot be dissipated, a heat pool due to the heat released by the crystallization reaction, that is, , A temperature higher than the surroundings is generated, and the temperature exceeds the compound phase precipitation start temperature depending on the conditions. Therefore, coarsening of crystal grains and precipitation of compound phase may occur.

On the other hand, in an example according to the present embodiment, when the heat radiating gas 50 of forced convection is applied to the end surface 10Zs on the opposite side in the plane direction of the laminated body 10 in the heat radiating step, as shown in FIG. In addition, even if the dimension of the amorphous alloy ribbon 2 in the laminated body 10 in the plane direction varies, the radiating gas 50 of forced convection is applied to the end surface 2Zs of all the amorphous alloy ribbons 2 on the opposite side in the plane direction. be able to. Therefore, heat can be dissipated from the end faces 2Zs of all the amorphous alloy ribbons 2 on the opposite side in the plane direction.

Therefore, in the example according to the present embodiment, it is possible to suppress the generation of heat pools due to the heat released due to the crystallization reaction in the portion close to the end surface 2Zs on the opposite side in the plane direction of all the amorphous alloy ribbons 2. Thereby, coarsening of crystal grains and precipitation of compound phase can be suppressed.

As described above, according to the present embodiment, after heating the laminated body in which the plurality of amorphous alloy ribbons are laminated in the first heat treatment step to the first temperature range below the crystallization start temperature of the amorphous alloy ribbons, In the second heat treatment step, by heating the end portion of the laminated body in the parallel direction to the second temperature range equal to or higher than the crystallization start temperature, when the laminated body is going to be crystallized, the heat dissipation step of applying a heat dissipation gas causes It is possible to suppress the occurrence of heat accumulation in a portion near the end surface on the side opposite to the above-mentioned end portion in the laminated body, and to suppress the coarsening of crystal grains and the precipitation of the compound phase. That is, when an alloy ribbon obtained by crystallizing an amorphous alloy ribbon is manufactured with high productivity, coarsening of crystal grains and precipitation of a compound phase can be suppressed.

Next, the method for manufacturing the alloy ribbon according to this embodiment will be described in detail focusing on the conditions.

1. Preparation Step In the preparation step, a laminated body in which a plurality of amorphous alloy ribbons are laminated is prepared.

The material of the amorphous alloy ribbon is not particularly limited as long as it is an amorphous alloy, and examples thereof include a Fe-based amorphous alloy, a Ni-based amorphous alloy, and a Co-based amorphous alloy. Of these, Fe-based amorphous alloys and the like are preferable. Here, the "Fe-based amorphous alloy" means an alloy containing Fe as a main component and containing impurities such as B, Si, C, P, Cu, Nb, and Zr. “Ni-based amorphous alloy” means an alloy containing Ni as a main component. The “Co-based amorphous alloy” means an alloy containing Co as a main component.

As the Fe-based amorphous alloy, for example, one having a Fe content in the range of 84 atomic% or more is preferable, and one having a larger Fe content is preferable. This is because the magnetic flux density of the alloy ribbon obtained by crystallizing the amorphous alloy ribbon changes depending on the Fe content.

The shape of the amorphous alloy ribbon is not particularly limited, but examples thereof include simple rectangular and circular shapes, and the shape of the alloy ribbon used for cores (stator core, rotor core, etc.) used in parts such as motors and transformers. To be For example, when the material is an Fe-based amorphous alloy, the size (length×width) of the rectangular amorphous alloy ribbon is, for example, 100 mm×100 mm, and the diameter of the circular amorphous alloy ribbon is, for example, 150 mm. Is.

The thickness of the amorphous alloy ribbon is not particularly limited, but varies depending on the material of the amorphous alloy ribbon, and in the case of a Fe-based amorphous alloy, for example, is in the range of 10 μm or more and 100 μm or less, and particularly 20 μm or more and 50 μm. The following range is preferable.

The number of laminated amorphous alloy ribbons is not particularly limited, but varies depending on the material of the amorphous alloy ribbons, and in the case of a Fe-based amorphous alloy, for example, 500 sheets or more and 10000 sheets or less is preferable. This is because if the amount is too small, the nanocrystalline alloy ribbon cannot be produced with high productivity, and if the amount is too large, the transportation becomes difficult and the handling becomes difficult.

The thickness of the laminated body is not particularly limited, but varies depending on the material of the amorphous alloy ribbon, and in the case of a Fe-based amorphous alloy, for example, 1 mm or more and 150 mm or less is preferable. This is because if it is too thin, the nanocrystalline alloy ribbon cannot be produced with high productivity, and if it is too thick, it becomes difficult to handle because it becomes difficult to carry.

2. First heat treatment step In the first heat treatment step, the laminated body is heated to a first temperature range below the crystallization start temperature of the amorphous alloy ribbon. Specifically, for example, the entire laminated body is soaked that the temperature of all the amorphous alloy ribbons in the laminated body falls within the first temperature range.

In the present invention, the “crystallization start temperature” means the temperature at which crystallization starts when the amorphous alloy ribbon is heated. The crystallization of the amorphous alloy ribbon depends on the material of the amorphous alloy ribbon, and in the case of a Fe-based amorphous alloy, it means, for example, to precipitate fine bccFe crystals. The crystallization start temperature varies depending on the material of the amorphous alloy ribbon and the heating rate. If the heating rate is high, the crystallization start temperature tends to increase. However, in the case of a Fe-based amorphous alloy, for example, 350° C. Within the range of up to 500°C.

The first temperature range is, for example, a state in which the stacked body is maintained in the first temperature range, by heating the end portions in the parallel direction of the stacked body to a second temperature range to be described later that is equal to or higher than the crystallization start temperature. It is a temperature range where the whole body can be crystallized.

The first temperature range is not particularly limited, but varies depending on the material of the amorphous alloy ribbon, and in the case of a Fe-based amorphous alloy, for example, a range of crystallization start temperature −100° C. or more and less than the crystallization start temperature is preferable. This is because if it is too low, the entire laminated body may not be crystallized by the second heat treatment step. On the other hand, if it is too high, the second heat treatment step may cause coarsening of crystal grains and precipitation of compound phase in the laminated body. This is because crystallization may start.

The method of heating the laminate to the first temperature range is not particularly limited, but may be a method of heating in a heating furnace or a method of heating by induction heating in an air atmosphere.

3. Second heat treatment step In the second heat treatment step, after the first heat treatment step, the end portion in the plane direction of the stacked body is heated to a second temperature range equal to or higher than the crystallization start temperature. Specifically, after the first heat treatment step, crystallization of the end portion of the laminated body in the plane direction is started while maintaining a portion other than the end portion of the laminated body in the plane direction in a temperature range lower than the crystallization start temperature. By heating to a second temperature range equal to or higher than the temperature and holding in the second temperature range for a time required for crystallization, the amorphous alloy at the end portion in the plane direction of the laminate is crystallized into a nanocrystalline alloy.

The end portion of the laminated body in the plane direction is not particularly limited, and examples thereof include one end portion of all the amorphous alloy ribbons of the laminated body in the plane direction.

The second temperature range is not particularly limited, but is preferably a temperature range below the compound phase precipitation start temperature. This is because precipitation of the compound phase can be suppressed. In the present invention, the "compound phase precipitation start temperature" means, for example, the temperature at which the precipitation of the compound phase starts when the amorphous alloy ribbon having the crystallization start temperature or higher is further heated. Further, the "compound phase" is, for example, a compound phase such as Fe-B or Fe-P in the case of an Fe-based amorphous alloy, which precipitates when the amorphous alloy ribbon after crystallization is further heated. , Means a compound phase that significantly deteriorates the soft magnetic properties as compared with the case where the crystal grains become coarse.

The second temperature range is not particularly limited, but varies depending on the material of the amorphous alloy ribbon, and in the case of a Fe-based amorphous alloy, for example, is preferably within a range from the crystallization start temperature to the crystallization start temperature +150°C. Among them, the crystallization start temperature +100°C or higher and the crystallization start temperature +120°C or lower or the crystallization start temperature +30°C or higher and the crystallization start temperature +80°C or lower are preferable. If it is too low, the entire laminate may not be crystallized, and if it is too high, coarsening of crystal grains and precipitation of compound phase may occur in the laminate.

The method of heating the end of the laminate in the plane direction to the second temperature range is not particularly limited as long as the amorphous alloy at the end of the laminate in the plane direction can be crystallized. For example, the method shown in FIG. As an example, other than the method of irradiating radiant heat of a high-temperature heat source such as a lamp on the end face in the plane direction of the laminate, the end face in the plane direction of the laminate, for example, a high temperature such as copper having good thermal conductivity. Examples include a method in which a high temperature liquid such as a plate and a salt bath, a heater, and a high temperature heat source such as a high frequency are brought into contact with each other.

The method of irradiating the radiant heat of the high-temperature heat source to the end face in the plane direction of the laminate is not particularly limited as long as the end portion in the plane direction of the laminate is heated to the second temperature range and can be held only for the time required for crystallization, For example, the irradiation time and the irradiation area are appropriately set according to the size of the alloy ribbon so that the entire laminated body can be crystallized without causing precipitation of the compound phase and coarsening of the crystal grains. can do. Further, the method of bringing a high-temperature heat source into contact with the end surface of the laminate in the planar direction is not particularly limited as long as the end portion of the laminate can be heated to the second temperature range and can be held for a time necessary for crystallization. It is possible to appropriately set the contact time, the contact area, etc. depending on the size of the alloy ribbon so that the entire laminate can be crystallized without causing the precipitation of phases and the coarsening of crystal grains. it can.

4. Heat Dissipating Step In the heat dissipating step, heat radiating gas is applied to the end surface of the laminate, which is opposite to the end in the plane direction. Specifically, forced convection heat-radiating gas is applied to the end surface of the laminated body, which is opposite to the end portion heated in the second heat treatment step in the plane direction. Thereby, by dissipating the heat from the end face of the laminate, the heat accumulation due to the heat released by the crystallization reaction is suppressed in the portion near the end face of the laminate, and the coarsening of the crystal grains and the compound are suppressed. Suppress the precipitation of phases.

The heat radiating step is not particularly limited as long as it is a step of applying a heat radiating gas to the end surface of the laminated body on the opposite side to the end surface in the plane direction. In the step of applying a heat-releasing gas to the end surface before heating to, or in the step of applying the heat-releasing gas to the end surface after heating the end of the laminate to the second temperature range in the second heat treatment step. Although it is good, normally, as in the example shown in FIG. 2D, a step of applying a heat-releasing gas to the end face after heating the end portion of the laminate to the second temperature range in the second heat treatment step. Become. This is because heat accumulation can be effectively suppressed.

Here, FIG. 5 and FIG. 6 are schematic process diagrams showing a second heat treatment process and a heat dissipation process in another example of the method for manufacturing an alloy ribbon according to the present embodiment, respectively, and are shown in FIG. It is a figure corresponding to a schematic process drawing. Hereinafter, with respect to another example of the method for manufacturing the alloy ribbon according to the present embodiment, the points different from the above-described example according to the present embodiment will be described.

In another example according to this embodiment shown in FIG. 5, in the heat dissipation step, the radiation thermometer 43 is used after the end portions 2A of all the amorphous alloy ribbons 2 are heated to the second temperature range in the second heat treatment step. The temperature of the end face 2Zs on the opposite side in the plane direction of all the amorphous alloy ribbons 2 is measured by the control unit 44, and the portion close to the end face 2Zs on the opposite side in the plane direction of the amorphous alloy ribbon 2 is controlled by the control unit 44. The fan 40 in the heating furnace 20 is rotated by the drive unit 45 when the generation of heat release due to the crystallization reaction in is detected. In this way, the atmosphere in the heating furnace 20 is sent toward the end surface 10Zs on the side opposite to the plane direction of the laminated body 10 and is recirculated in the heating furnace 20. As a result, forced convection of the heat radiating gas 50 is generated, and the heat radiating gas 50 of forced convection is applied to the end surface 10Zs of the laminated body 10 on the opposite side in the plane direction.

In another example according to this embodiment shown in FIG. 6, in the heat dissipation step, the radiation thermometer 43 is used after the end portions 2A of all the amorphous alloy ribbons 2 are heated to the second temperature range in the second heat treatment step. The temperature of the end face 2Zs on the opposite side in the plane direction of all the amorphous alloy ribbons 2 is measured by the control unit 44, and the portion close to the end face 2Zs on the opposite side in the plane direction of the amorphous alloy ribbon 2 is controlled by the control unit 44. When the release heat generated by the crystallization reaction is detected, the shutter 46 that shields the air blown by the fan 40 rotating in the heating furnace 20 is opened by the drive unit 47 as indicated by the broken line. In this way, the outside air taken into the heating furnace 20 from the air supply port 41 is sent toward the end surface 10Zs on the opposite side of the laminate 10 in the plane direction, and the atmosphere in the heating furnace 20 is discharged from the exhaust port 42. As a result, forced convection of the heat radiating gas 50 is generated, and the heat radiating gas 50 of forced convection is applied to the end surface 10Zs of the laminated body 10 on the opposite side in the plane direction.

As the heat radiating step, for example, like the heat radiating step shown in FIGS. 5 and 6, the temperature of the end surface of the laminated body on the side opposite to the end in the plane direction is measured, and the temperature of the laminated body is measured based on the measured temperature. When the generation of heat release due to a crystallization reaction in a portion near the end surface on the opposite side to the plane direction from the end portion is detected, a heat-releasing gas is formed on the end surface on the opposite side to the end portion in the plane direction of the laminate. The step of applying is preferred. As a result of applying a heat-releasing gas to the end face before the crystallization reaction occurs in a portion close to the end face on the side opposite to the end face in the laminate, the temperature of the laminate unnecessarily decreases, This is because it is possible to prevent the body from being unable to crystallize.

The temperature of the heat radiating gas is not particularly limited as long as it is a temperature that can suppress the coarsening of crystal grains and the precipitation of the compound phase by radiating heat from the end face of the amorphous alloy ribbon, but the material of the amorphous alloy ribbon In the case of a Fe-based amorphous alloy, for example, it is preferably in the range below the crystallization start temperature, more preferably in the range below the crystallization start temperature −320° C. and below the crystallization start temperature, and especially crystallization. It is preferable that the starting temperature is −220° C. or higher and the crystallization starting temperature is lower than −120° C. It is because when it is at least the lower limit, it is possible to prevent the temperature of the laminated body from being lowered and the laminated body cannot be crystallized, and when it is less than the upper limit, heat can be effectively dissipated.

The method of applying the heat-releasing gas to the end surface of the laminated body is not particularly limited as long as it can dissipate the heat from the end surfaces of all the amorphous alloy ribbons. For example, the heat dissipation shown in FIGS. As in the process, the outside air taken into the heating furnace from the air supply port is sent toward the end surface of the laminate that is opposite to the one end surface in the plane direction, and the atmosphere in the heating furnace is discharged from the exhaust port. Alternatively, a method of applying a heat-releasing gas of forced convection generated by the above may be used. This is because the heat can be effectively dissipated. Further, as in the heat dissipation step shown in FIG. 5, the atmosphere in the heating furnace is sent toward the end surface of the laminate which is opposite to the one end surface in the plane direction, and is refluxed in the heating furnace. A method of applying the generated heat-releasing gas of forced convection may be used. This is because it is possible to prevent the temperature of the laminated body from decreasing and the laminated body from being unable to be crystallized.

5. Atmosphere temperature In the method for manufacturing an alloy ribbon according to the present embodiment, crystallization can be performed by heating the end portion of the laminate to the second temperature range in the second heat treatment step after the first heat treatment step. The ambient temperature around the laminated body is maintained so that the laminated body is maintained in such a temperature range (hereinafter, may be abbreviated as “crystallizable temperature range”). In other words, after the first heat treatment step, the laminated body is maintained in a temperature range where crystallization of the laminated body can occur by heating the end portion of the laminated body in the plane direction in the second heat treatment step to the second temperature range. As described above, the ambient temperature around the laminated body is maintained. Specifically, after the first heat treatment step, the ambient temperature is maintained such that the amorphous portion of the alloy ribbon in the laminated body is maintained in the crystallizable temperature range.

The holding temperature of the ambient temperature is not particularly limited, but varies depending on the material of the amorphous alloy ribbon, and in the case of a Fe-based amorphous alloy, for example, the lower limit of the first temperature range is −10° C. or more and the upper limit of the first temperature range. The following range is preferable, and a range of the first temperature range is particularly preferable. If it is too low, it may not be possible to cause the crystallization reaction to propagate in the laminate, and if it is too high, coarsening of crystal grains and precipitation of the compound phase may occur in the laminate, This is because the cost will be high.

6. Relationship between Heat Amounts In the method for manufacturing an alloy ribbon according to the present embodiment, the heat amount required to heat the laminate to the first temperature range in the first heat treatment step is Q1, and the second heat treatment step is performed. In the case where the end portion of the laminate is heated to the second temperature range, the amount of heat given to the laminate is Q2, and the amount of heat released when the laminate is crystallized is Q3. When the amount of heat required to bring the above to the crystallization start temperature is Q4, the following formula (1) is satisfied. If the following formula (1) is not satisfied, the entire laminate may not be crystallized. It should be noted that Q4 is, more specifically, that the laminated body is heated by Q1 in the first heat treatment step, the end portion in the plane direction of the laminated body is heated by Q2 in the second heat treatment step, and the laminated body is formed after the second heat treatment step. In the temperature history of the laminated body when is heated by Q3, the amount of heat is necessary to bring the entire laminated body from the state before being heated by Q1 in the first heat treatment step to the crystallization start temperature. For example, in the above case, in particular, in the temperature history of the laminated body when there is no heat transfer between the laminated body and the outside in the above case, Q4 is the first heat treatment. It is the amount of heat required to reach the crystallization start temperature from the state before being heated by Q1 in the process.

Q1+Q2+Q3≧Q4 (1)

Further, when the above expression (1) is satisfied, the heat quantity required for heating each amorphous alloy ribbon in the laminated body in Q1 to the first temperature range is Qa1, and the amorphous alloy ribbon in Q2 is selected. The quantity of heat given to the amorphous alloy ribbon is Qa3, and the quantity of heat required to bring the entire amorphous alloy ribbon to the crystallization start temperature is Qa4. It is preferable that all the amorphous alloy ribbons in the body satisfy the following formula (1a). This is because it is possible to crystallize the entire amorphous alloy ribbon. More specifically, Qa4 is, more specifically, that each amorphous alloy ribbon in the laminated body is heated by Qa1 in the first heat treatment step, that amorphous alloy ribbon is heated by Qa2 in the second heat treatment step, and the second heat treatment is performed. In the temperature history of the amorphous alloy ribbon when the amorphous alloy ribbon is heated by Qa3 after the step, the entire amorphous alloy ribbon is crystallized from the state before being heated by Qa1 in the first heat treatment step. It is the amount of heat required to reach the starting temperature. Qa4 is, for example, in the above case, in particular, in the temperature history of the amorphous alloy ribbon when there is no heat transfer between the amorphous alloy ribbon and the outside except that it is heated by Qa1, Qa2, and Qa3. The amount of heat required to bring the entire amorphous alloy ribbon to the crystallization start temperature from the state before being heated by Qa1 in the first heat treatment step. The examples shown in FIGS. 1 and 2 satisfy the following formula (1a).

Qa1+Qa2+Qa3≧Qa4 (1a)

In addition, in the method for manufacturing the alloy ribbon according to the present embodiment, normally, in order to crystallize the entire laminated body by using the amount of heat released when the laminated body is crystallized, the amount of heat given from outside (Q1 And Q2) does not exceed the amount of heat (Q4) required to bring the entire laminated body to the crystallization start temperature, and satisfies the following formula (2).

Q1+Q2<Q4 (2)

Further, in the method for producing an alloy ribbon according to the present embodiment, it is preferable that the following formula (3) is satisfied when the amount of heat required to bring the entire laminated body to the compound phase precipitation start temperature is Q5. .. This is because precipitation of the compound phase can be suppressed. Note that, more specifically, Q5 means that the laminated body is heated by Q1 in the first heat treatment step, the end portion in the plane direction of the laminated body is heated by Q2 in the second heat treatment step, and the laminated body is formed after the second heat treatment step. In the temperature history of the laminated body when is heated by Q3, the amount of heat is necessary to bring the entire laminated body from the state before being heated by Q1 in the first heat treatment step to the compound phase precipitation start temperature. For example, in the above case, in particular, in the temperature history of the laminated body in the case where there is no heat transfer between the laminated body and the outside except for being heated by Q1 and Q2, Q5 is the first heat treatment for the entire laminated body. It is the amount of heat required to reach the compound phase precipitation start temperature from the state before being heated by Q1 in the process.

Q1+Q2+Q3<Q5 (3)

When the above expression (3) is satisfied, the heat quantity required to heat each amorphous alloy ribbon in the laminated body in Q1 to the first temperature range is Qa1, and the amorphous alloy ribbon in Q2 is selected. Qa2 is the amount of heat given to the amorphous alloy ribbon, and Qa3 is the amount of heat given to the amorphous alloy ribbon in Q3, and Qa5 is the amount of heat required to bring the entire amorphous alloy ribbon to the compound phase precipitation start temperature. It is preferable that all the amorphous alloy ribbons in the laminate satisfy the following formula (3a). This is because precipitation of the compound phase can be suppressed in all amorphous alloy ribbons. More specifically, Qa5 is, more specifically, that each amorphous alloy ribbon in the laminated body is heated by Qa1 in the first heat treatment step, the amorphous alloy ribbon is heated by Qa2 in the second heat treatment step, and the second heat treatment is performed. In the temperature history of the amorphous alloy ribbon when the amorphous alloy ribbon is heated by Qa3 after the process, the entire amorphous alloy ribbon is changed from the state before being heated by Qa1 in the first heat treatment step to the compound phase. It is the amount of heat required to reach the precipitation start temperature. Qa5 is, for example, in the above case, particularly in the temperature history of the amorphous alloy ribbon in the case where there is no heat transfer between the amorphous alloy ribbon and the outside except that it is heated by Qa1, Qa2, and Qa3. The amount of heat required to bring the entire amorphous alloy ribbon to the compound phase precipitation start temperature from the state before being heated by Qa1 in the first heat treatment step.

Qa1+Qa2+Qa3<Q5a (3a)

7. Method for producing alloy ribbon In the method for producing an alloy ribbon according to the present embodiment, a plurality of amorphous alloy ribbons in the laminate are crystallized from the end portion in the plane direction where the laminate is heated to the second temperature range. A plurality of nanocrystalline alloy ribbons with crystallized bands are produced.

Here, the "nanocrystalline alloy ribbon" means that a desired coercive force and other soft magnetic properties are obtained by precipitating fine crystal grains without substantially causing precipitation of a compound phase and coarsening of crystal grains. Is meant to be obtained. The material of the nanocrystalline alloy ribbon varies depending on the material of the amorphous alloy ribbon, and in the case of a Fe-based amorphous alloy, for example, Fe or Fe alloy crystal grains (for example, fine bccFe crystals) and amorphous. It becomes an Fe-based nanocrystalline alloy having a mixed phase structure of a substance phase.

The grain size of the crystal grains of the nanocrystalline alloy ribbon is not particularly limited as long as the desired soft magnetic characteristics can be obtained, but it varies depending on the material etc., and in the case of a Fe-based nanocrystalline alloy, it is, for example, 25 nm or less. It is preferably within the range. This is because the coercive force deteriorates when it becomes coarse.

The grain size of the crystal grains can be measured by direct observation using a transmission electron microscope (TEM). The grain size of crystal grains can be estimated from the coercive force or temperature profile of the nanocrystalline alloy ribbon.

The coercive force of the nanocrystalline alloy ribbon varies depending on the material of the nanocrystalline alloy ribbon and the like. In the case of Fe-based nanocrystalline alloy, it is, for example, 20 A/m or less, and preferably 10 A/m or less. By lowering the coercive force in this way, for example, the loss in the core of the motor or the like can be effectively reduced. Since the conditions such as the temperature range in each heat treatment step according to the present embodiment are limited, there is a limit to the reduction of the coercive force of the nanocrystalline alloy ribbon.

The method for producing the alloy ribbon according to the present embodiment is not particularly limited as long as it can produce a plurality of nanocrystalline alloy ribbons, for example, without substantially causing precipitation of a compound phase and coarsening of crystal grains, A production method is preferred in which the entire laminated body is crystallized, and the crystal grains of the nanocrystalline alloy ribbon in which the amorphous alloy ribbon in the laminated body is crystallized have a desired grain size. In the method for producing the alloy ribbon described above, the precipitation of the compound phase and the coarsening of the crystal grains are not substantially caused, and the entire laminate is crystallized, and the crystal grains of the nanocrystalline alloy ribbon are formed into desired grains. In order to set the diameter, not only the conditions described so far, but also other conditions can be suitably set. Further, not only each condition can be set independently but also a combination of each condition can be set appropriately. In addition, coarsening of the crystal grains and precipitation of the compound phase in a portion close to the end face on the opposite side to the plane direction with respect to the end portion of the laminated body can be suppressed by a heat dissipation step, but the crystal at the end portion of the laminated body The coarsening of grains and the precipitation of the compound phase can be suppressed by the heating conditions in the second heat treatment step.

Hereinafter, the method for manufacturing the alloy ribbon according to the present embodiment will be described more specifically with reference to Examples and Reference Examples.

[Example]
The simulation of the method for manufacturing the alloy ribbon according to the present embodiment was performed using the CAE (Computer Aided Engineering) method. The details will be described below.

<Computational model of laminated body of amorphous alloy ribbon>
As a calculation model of a laminated body of amorphous alloy ribbons used in the simulation, a calculated model M10 of a laminated body as shown in FIG.

Specifically, as shown in FIG. 7, the calculation model M10 of the laminated body includes a tooth portion (corresponding to the tooth portion M10T of the calculation model M10) of one amorphous alloy ribbon in the laminated body used for the stator core. The back yoke portion (corresponding to the back yoke portion M10Y of the calculation model M10) was manufactured as having a shape divided by the symmetry plane (corresponding to the symmetry plane MS of the calculation model M10). The size of each part of the calculation model M10 of the laminated body was set as follows.

Alloy ribbon thickness T2: 0.025 mm
Length L3 of the part corresponding to part of the outer circumference of the alloy ribbon: 7 mm
Length L4 of the part corresponding to a part of the inner circumference of the alloy ribbon: 3 mm
Radial width W2: 35 mm
Radial length Lt2 of the tooth portion M10T: 20 mm
Circumferential width Wt2 of the groove between the tooth portions M10T: 2 mm

The calculation model M10 of the laminated body was prepared assuming that the amorphous alloy ribbon was composed of a general Fe-based amorphous alloy, and the parameters necessary for the simulation regarding the amorphous alloy ribbon were set as follows.

Crystallization start temperature: 360°C
Compound phase precipitation start temperature: 530°C
Thermal conductivity: 10W/mK
Heat release due to crystallization: 90 J/g

In the calculation model M10 of the laminated body, the heat transfer coefficient between the adjacent amorphous alloy ribbons on both sides in the laminating direction is set to 50 W/(m ² K), whereby the laminating direction of one amorphous alloy ribbon is set. Was modeled by considering the heat transfer between the amorphous alloy ribbons on both sides of the.

<Simulation conditions>
The simulation was performed using CAE software (DEFORM manufactured by SFTC) using the above-described laminated body calculation model M10.

In the simulation, first, the entire temperature of the calculation model M10 of the stacked body was heated to 320° C. (first temperature range), which is lower than the crystallization start temperature (first heat treatment step).

Next, by setting the boundary condition of the temperature of the outer peripheral side end face M10As in the plane direction of the laminated body calculation model M10 to 500° C., crystallization of the outer peripheral side end portion M10A in the plane direction of the laminated body calculation model M10 is started. It heated in the temperature range (2nd temperature range) above temperature (2nd heat processing process).

Further, the heat transfer coefficient between the inner peripheral side end surface M10Zs in the plane direction of the laminate calculation model M10 and the outside is preliminarily set to 50 W/(m ² K) corresponding to the heat transfer coefficient in forced convection in the heating furnace. By setting, after heating the outer peripheral side end portion M10A of the calculation model M10 of the laminated body in the plane direction in the second heat treatment step to a temperature range equal to or higher than the crystallization start temperature, the plane direction of the calculation model M10 of the laminated body is set. A process of applying a forced convection heat radiation gas to the inner peripheral side end surface M10Zs was simulated (heat radiation step).

Then, in the simulation, after the first heat treatment step, in the second heat treatment step, the temperature at which crystallization can be performed by heating the outer peripheral side end portion M10A of the calculation model M10 of the laminated body in the plane direction to a temperature range equal to or higher than the crystallization start temperature. The ambient temperature around the calculation model M10 of the laminate was kept at 320° C. so that the whole calculation model M10 of the laminate was maintained in the region. Then, the above formula (1) according to the present embodiment is satisfied. In addition, the heat transfer between the calculation model M10 of the laminated body and the atmosphere around it was also included.

<Analysis result>
The temperature change at each position of the calculation model M10 of the laminated body was analyzed by simulation. FIG. 7: is a figure which shows the image of the temperature of each position of the calculation model of a laminated body in 52 seconds after heating the outer peripheral side edge part in the plane direction in an Example.

In the calculation model M10 of the laminated body, although not shown, after heating the outer peripheral side end M10A in the plane direction, the outer peripheral side end M10A in the plane direction, the central portion M10M, and the inner peripheral side end M10Z are crystallized in this order. The temperature was higher than the starting temperature, and as shown in FIG. 7, the entire temperature became higher than the crystallization starting temperature 52 seconds after the outer peripheral side end M10A was heated. Then, 52 seconds after and after the heating of the outer peripheral side end M10A in the planar direction, heat is accumulated in a portion close to the inner peripheral side end face M10Zs in the planar direction, specifically, at a temperature higher than that of the surroundings. No part exceeding 525°C was generated.

[Comparative example]
A simulation of the method for manufacturing the alloy ribbon of the comparative example was performed using the CAE method. The details will be described below.

<Computational model of laminated body of amorphous alloy ribbon>
As a calculation model of a laminated body of amorphous alloy ribbons used for simulation, a calculation model M10 of a laminated body as shown in FIG. The calculation model M10 of the laminated body is the same as the calculation model M10 of the laminated body manufactured in the example.

<Simulation conditions>
In the simulation, in the heat dissipation step, the heat transfer coefficient between the inner peripheral side end surface M10Zs of the calculation model M10 of the laminate and the outside is 10 W/(m corresponding to the heat transfer coefficient in natural convection in the heating furnace. except that preset to ^{2 K),} it was carried out under the same conditions as in the simulation examples.

<Analysis result>
The temperature change at each position of the calculation model M10 of the laminated body was analyzed by simulation. FIG. 8A and FIG. 8B are temperatures of respective positions of the calculation model of the laminated body at 20 seconds and 52 seconds after heating the outer peripheral side end portion in the plane direction in the comparative example, respectively. It is a figure which shows an image.

In the calculation model M10 of the laminated body, as shown in FIGS. 8A and 8B, after heating the outer peripheral side end M10A in the plane direction, the outer peripheral side end M10A in the plane direction and the central part M10M and the inner peripheral side end portion M10Z were in order above the crystallization start temperature, and 52 seconds after the outer peripheral side end portion M10A was heated, the whole was above the crystallization start temperature. Then, at and after 52 seconds from the heating of the outer peripheral side end portion M10A in the plane direction, heat accumulation occurred in a portion close to the inner peripheral side end surface M10Zs in the plane direction. Specifically, there were places where the temperature exceeded 525°C, which was higher than the surrounding temperature, and the temperature of the highest place was 545°C.

Although the embodiment of the method for manufacturing the alloy ribbon according to the present invention has been described above in detail, the present invention is not limited to the above-described embodiment, and the spirit of the present invention described in the claims is Various design changes can be made without departing from the scope.

2 Amorphous alloy ribbon 10 Laminated body 30 High temperature heat source 50 Gas for heat radiation

Claims (1)

A preparatory step of preparing a laminated body in which a plurality of amorphous alloy ribbons are laminated,
A first heat treatment step of heating the laminated body to a first temperature range below a crystallization start temperature of the amorphous alloy ribbon;
After the first heat treatment step, a second heat treatment step of heating the end portion in the plane direction of the stacked body to a second temperature range equal to or higher than the crystallization start temperature,
A heat dissipation step of applying a heat dissipation gas to an end surface on the opposite side to the end portion in the plane of the laminate,
Equipped with
After the first heat treatment step, by heating the end portion of the laminate in the second heat treatment step to the second temperature range, the laminate is maintained in a temperature range where crystallization is possible. Maintaining the ambient temperature around the body,
When the amount of heat required to heat the laminated body to the first temperature range in the first heat treatment step is Q1, and the end portion of the laminated body is heated to the second temperature range in the second heat treatment step When the amount of heat given to the laminate is Q2, the amount of heat released when the laminate is crystallized is Q3, and the amount of heat required to bring the entire laminate to the crystallization start temperature is Q4 And a method of manufacturing an alloy ribbon, which satisfies the following formula (1).
Q1+Q2+Q3≧Q4 (1)