JP6327835B2 - Laminated magnetic body, laminated magnetic core and manufacturing method thereof - Google Patents

Description

  The present invention relates to a laminated magnetic body suitable for a transformer, an inductor, and a reactor magnetic core, a laminated magnetic core, and a manufacturing method thereof.

  The Fe-based nanocrystalline alloy is a soft magnetic material capable of achieving both high saturation magnetic flux density and low magnetostriction. In order to obtain this Fe-based nanocrystalline alloy, it is necessary to heat-treat the soft magnetic alloy composition having an amorphous structure to precipitate fine bccFe crystals (α-Fe).

  However, self-heating occurs when fine crystals are precipitated, and compounds such as Fe-B may be precipitated in addition to α-Fe crystals. The precipitation of the compound such as Fe-B causes a problem that desired magnetic properties cannot be obtained.

  In addition, if the heat generation accompanying fine crystal precipitation becomes excessive, there is a problem that crystal grains grow too much and sufficient magnetic properties cannot be obtained.

  It is known that when a metal element such as Nb or Zr is added to the composition of the Fe-based amorphous alloy, crystal grain growth during heat treatment can be suppressed. However, when these metal elements are added, there arises a problem that the saturation magnetic flux density is lowered and the product price is affected because Nb and Zr are expensive.

  On the other hand, when a composition of an Fe-based amorphous alloy not added with a metal element such as Nb or Zr is used, a high saturation magnetic flux density can be obtained, but since the crystal grain growth is fast, the heating rate of the heat treatment is low. As a result, the crystal becomes coarse and sufficient magnetic properties cannot be obtained.

  Here, the crystallization temperature at which a compound such as α-Fe crystal or Fe-B precipitates will be described. When a soft magnetic alloy composition having an amorphous structure is heat-treated, heat is generated due to a change in phase structure when a compound such as α-Fe crystal or Fe-B is precipitated. The temperature at which this heat is generated and the amount of heat generated can be known by measuring with a differential scanning calorimeter (DSC). FIG. 3 is a diagram showing the results of measuring the exothermic behavior of the soft magnetic alloy composition with a differential scanning calorimeter (DSC). As shown in FIG. 3, when the soft magnetic alloy composition having an amorphous structure is heat-treated, two exothermic peaks are confirmed. The peak on the low temperature side is due to the exotherm accompanying the precipitation of the α-Fe crystal, and the peak on the high temperature side is due to the heat generation associated with the compound precipitation. The temperature 31 at which the crystallization of the α-Fe crystal starts is referred to as a first crystallization temperature (Tx1), and the temperature 32 at which the crystallization of a compound such as Fe-B starts is referred to as a second crystallization temperature (Tx2). A temperature difference (Tx2−Tx1) between the second crystallization temperature and the first crystallization temperature is represented by ΔT, and when ΔT is large, the heat treatment can be stably performed.

  In the prior art, when forming a magnetic core, a method of forming a soft magnetic alloy powder into a desired shape, a method of stacking thin ribbons made of soft magnetic alloys, a thin ribbon made of soft magnetic alloys A method of winding a ring in a ring shape is used.

  As shown in FIG. 2, in the magnetic core 2 produced by winding the soft magnetic alloy ribbon 21 in a ring shape, the thickness of the laminated soft magnetic alloy ribbon 21 is larger than the inner side 22 and the outer side 23 exposed on the surface of the magnetic core 2. In the interior 24 which is an intermediate portion, heat generated by fine crystal precipitation tends to concentrate. Further, since the inside 24 of the magnetic core 2 is most difficult to dissipate heat than the inside 22 and the outside 23 of the magnetic core 2, thermal runaway is likely to occur. In particular, when the magnetic core is large, more remarkable self-heating occurs, and sufficient magnetic properties cannot be obtained.

  As a conventional heat treatment method for suppressing self-heating when fine crystals are precipitated, there is a method disclosed in Patent Document 1, for example. Patent Document 1 discloses a method for preventing an excessive temperature rise due to self-heating by performing heat treatment at least twice at a temperature higher than the crystallization start temperature and substantially not forming a compound phase.

JP 2003-213331 A

  However, since the prior art includes a temperature lowering process for lowering the temperature of the magnetic core after the first heat treatment, there is a problem that if the number of heat treatments is increased, it takes time to increase.

  Moreover, even if the first heat treatment is terminated when heat generation due to crystallization starts, the inside of the magnetic core, which is the middle part of the thickness of the laminated ribbons, is compared to the inside and outside exposed on the surface of the magnetic core. Since it is difficult to dissipate heat, there is a problem that the temperature rises and the desired magnetic properties cannot be obtained. That is, the larger the magnetic core, the higher the internal temperature and the lower the magnetic properties due to the increase in the amount of self-heating and the decrease in heat dissipation.

  Furthermore, even if the first heat treatment is terminated when the heat generation due to crystallization starts, if the atmospheric temperature in the heat treatment furnace is maintained at the same temperature as when the heat treatment is terminated, the heat radiation is still performed. There is a problem that the magnetic core temperature rises and sufficient magnetic properties cannot be obtained without proceeding as desired. In this case as well, the larger the magnetic core, the higher the internal temperature increases due to the increase in the amount of self-heating and the decrease in heat dissipation, and the magnetic characteristics deteriorate.

  Accordingly, an object of the present invention is to provide a laminated magnetic core that suppresses the precipitation of a compound and has excellent magnetic properties.

  In order to solve the above problems, according to the present invention, at least two layers of soft magnetic ribbons made of an Fe-based amorphous alloy are laminated, and one of the soft magnetic ribbons has an average grain size in a precipitated crystal after heat treatment However, a laminated magnetic core larger than the average particle diameter in the precipitated crystal after heat treatment of the other soft magnetic ribbon is obtained.

  In the laminated magnetic core of the present invention, the soft magnetic ribbon having the smaller average particle diameter is laminated in the range of 1 to 10 layers with respect to the soft magnetic ribbon having the larger average particle diameter. It is desirable that

  In addition, the soft magnetic ribbon of the laminated magnetic core of the present invention may be composed of two types: an amorphous single-phase soft magnetic ribbon and a partially crystalline ribbon that leaves an amorphous phase inside the soft magnetic ribbon. desirable.

  The laminated magnetic core of the present invention preferably has a space factor of 80% or more.

  The laminated magnetic core of the present invention desirably has an average particle size of 25 nm or less in the precipitated crystals after heat treatment.

  According to the present invention, an amorphous single-phase soft magnetic ribbon made of an Fe-based amorphous alloy and a partially crystalline thin film in which an amorphous phase remains inside the soft-magnetic ribbon made of an Fe-based amorphous alloy. A laminated magnetic body in which bands are laminated is obtained.

  In the laminated magnetic body of the present invention, it is desirable that one layer or more and ten or less layers of the partial crystal ribbon are laminated with respect to one layer of the soft magnetic ribbon.

  According to the present invention, an amorphous single-phase soft magnetic ribbon made of an Fe-based amorphous alloy is produced, and an amorphous phase is left inside the soft-magnetic ribbon made of an Fe-based amorphous alloy. A method of manufacturing a laminated magnetic core having a step of manufacturing a partially crystalline ribbon and a step of laminating the soft magnetic ribbon and the partially crystalline ribbon and heat-treating them is obtained.

  According to the present invention, since the partially crystalline ribbon that has left the amorphous phase has already been partially crystallized, the amount of self-heating generated by the heat treatment is small, and the self-heating of the laminated magnetic core produced by superimposing the soft magnetic ribbon The total amount of heat generation can be reduced.

  In addition, as a method for improving heat dissipation, there are known a method of laminating a soft magnetic ribbon and a crystalline metal ribbon for heat dissipation, and a method of winding a soft magnetic ribbon around a metal member for heat dissipation. However, in these methods, in order to improve the space factor, a step of removing a metal strip or metal member for heat dissipation after heat treatment is required. Moreover, after removing the metal strip or metal member for heat dissipation, the process of rewinding a magnetic body again or restacking is also needed.

  According to the present invention, since the partial crystal ribbon also plays a role of heat dissipation against the self-heating of the soft magnetic ribbon, these steps are unnecessary, and an excessive temperature rise of the laminated magnetic core can be suppressed.

  From the above, it is possible to obtain a laminated magnetic body, a laminated magnetic core and a method for producing the same, which suppress the precipitation of the compound and have excellent magnetic properties.

It is the schematic which shows the laminated magnetic core by this invention. It is the schematic which shows the magnetic core by a prior art. It is a figure which shows the result of having measured the exothermic behavior of the soft magnetic alloy composition with the differential scanning calorimeter (DSC).

  Hereinafter, embodiments of the present invention will be described in detail.

(First embodiment)
FIG. 1 is a schematic view showing a laminated magnetic core according to the present invention. As shown in FIG. 1, an amorphous single-phase soft magnetic ribbon 11 made of an Fe-based amorphous alloy and a portion in which an amorphous phase remains inside the soft-magnetic ribbon made of an Fe-based amorphous alloy The crystal ribbon 12 is overlapped and wound to produce a laminated magnetic body. Thereafter, heat treatment is performed to manufacture the laminated magnetic core 1.

  First, an amorphous single-phase soft magnetic ribbon 11 made of an Fe-based amorphous alloy is produced, and a soft magnetic ribbon made of an Fe-based amorphous alloy is subjected to heat treatment to produce a partial crystal ribbon 12. . The conditions for this heat treatment may be appropriately set at a temperature and a time at which an α-Fe crystal can be precipitated and a compound such as Fe—B does not precipitate. Specifically, the heat treatment temperature may be set at a first crystallization temperature of −100 ° C. or more and less than the second crystallization temperature, and the heat treatment time may be appropriately set at 0.01 seconds or more and 600.00 seconds or less. When it is performed, the heat treatment is performed in a short time, and when it is performed at a low temperature, the heat treatment may be performed for a long time.

  Thereafter, the soft magnetic ribbon 11 and the partial crystal ribbon 12 are overlapped and wound to produce a laminated magnetic body. By heat-treating the produced laminated magnetic body, crystallization starts from the inside and outside exposed on the surface of the laminated magnetic body, and heat is transferred toward the inside of the laminated magnetic body that is the middle part of the thickness of the laminated ribbon. The laminated magnetic core 1 is produced by completely precipitating fine α-Fe crystals on the soft magnetic ribbon 11 and the partial crystal ribbon 12.

  The heat treatment conditions for the laminated magnetic material may be set as appropriate at a temperature and a time at which α-Fe crystals can be precipitated and a compound such as Fe-B does not precipitate. Specifically, the heat treatment temperature may be set at a first crystallization temperature of −100 ° C. or more and less than the second crystallization temperature, and the heat treatment time may be appropriately set at 1.00 seconds or more and 3600.00 seconds or less. When it is performed, the heat treatment is performed in a short time, and when it is performed at a low temperature, the heat treatment may be performed for a long time.

  Further, there is no particular limitation on the heat treatment method for producing the partial crystal ribbon and the heat treatment of the laminated magnetic material, and a conventional heat treatment method such as in an inert gas atmosphere such as argon may be used.

  The partial crystal ribbon 12 has a small amount of self-heating due to the heat treatment because fine α-Fe crystals are precipitated in a part of the soft magnetic ribbon. Therefore, by using a laminated magnetic body in which the partial crystal ribbon 12 and the soft magnetic ribbon 11 are laminated, the amount of self-heating of the laminated magnetic core 1 caused by the heat treatment can be reduced. Even when the laminated magnetic core is large, the self-heating amount of the laminated magnetic core 1 due to the heat treatment is reduced.

  In addition, since the partial crystal ribbon 12 has fine α-Fe crystals precipitated on a part of the soft magnetic ribbon, the coarse crystal even when the laminated core 1 is heat-treated at a low temperature increase rate. Can be suppressed. Therefore, the average grain size in the precipitated crystal of the partial crystal ribbon 12 is smaller than the average grain size in the precipitated crystal of the soft magnetic ribbon 11.

  In addition, since the self-heating of the soft magnetic ribbon 11 due to the heat treatment is radiated to the partial crystal ribbon 12 in addition to the air in the heat treatment, the heat dissipation of the laminated magnetic core 1 is improved, and the laminated magnetic core 1 is excessively heated. Temperature rise can be suppressed. Even when the laminated magnetic core is large, the self-heating of the soft magnetic ribbon 11 due to the heat treatment is dissipated in the air or to the adjacent partial crystal ribbon 12, so that it is an intermediate portion of the thickness of the laminated ribbon. Even in the laminated magnetic core 1, an excessive temperature rise can be suppressed.

  As described above, according to the present invention, the amount of self-heating can be reduced, and an excessive temperature rise of the laminated magnetic core can be suppressed. Therefore, heat treatment can be performed at a desired temperature condition, and not only a lightweight and small laminated magnetic core can be used. Even in a large-sized laminated magnetic core, crystal coarsening and precipitation of a compound such as Fe-B can be suppressed, and excellent magnetic properties can be obtained.

  That is, since the soft magnetic ribbon of the present invention can provide excellent magnetic properties with a composition to which a metal element such as Nb or Zr is added or a composition without the addition, an Fe—Si—B—Nb—Cu system, Use of an Fe-based amorphous alloy that precipitates α-Fe crystals by heat treatment, such as Fe— (Nb, Zr) —B, Fe— (Si, B, P, C) —Cu, etc. Is possible. The composition of the Fe- (Si, B, P, C) -Cu-based Fe-based amorphous alloy is preferably set within the range described below.

  Fe element is the main element responsible for magnetism, and it is desirable that the ratio is large in order to improve the saturation magnetic flux density and reduce the raw material price. In order to obtain a homogeneous fine crystal structure and to obtain a desired saturation magnetic flux density, the Fe ratio is desirably 79 at% or more, and in order to obtain a higher saturation magnetic flux density, 81 at% or more is more desirable. Further, when the amount of Fe is excessive, the ability to form an amorphous phase is reduced, and variation in crystal grain size and coarsening occur, resulting in a decrease in magnetic properties. Therefore, the Fe ratio is desirably 86 at% or less.

  The Si element is an element responsible for forming an amorphous phase and does not necessarily need to be included. However, since ΔT can be increased, it contributes to the stabilization of fine crystals during crystallization. If the amount of Si is excessive, the ability to form an amorphous phase is lowered and sufficient magnetic properties cannot be obtained. Therefore, the Si ratio is preferably 10 at% or less, and more preferably 8 at% or less.

  The B element is an element responsible for forming an amorphous phase, and the ratio of B is preferably 1 at% or more in order to stably produce a soft magnetic ribbon. Furthermore, ΔT can be enlarged, and at the time of crystallization, it contributes to the stabilization of fine crystals. Further, if the amount of B is excessive, the ability to form an amorphous phase is lowered and it becomes difficult to produce a soft magnetic ribbon. Therefore, it is preferably 15 at% or less, and 13 at% or less for obtaining a homogeneous fine crystal structure. More desirable. In particular, when the alloy composition needs to have a low melting point for mass production, the ratio of B is more preferably 10 at% or less.

  The P element is an element responsible for forming an amorphous phase and is an essential element for obtaining fine crystals. In order to stably produce a soft magnetic ribbon, the proportion of P is preferably 1 at% or more, and more preferably 3 at% or more in order to obtain a homogeneous fine crystal structure. Further, if the amount of P becomes excessive, ΔT becomes narrow and stable heat treatment becomes difficult, so 15 at% or less is desirable. Moreover, 10 at% or less is more desirable because a desired saturation magnetic flux density can be obtained, and 8 at% or less is more desirable because a higher saturation magnetic flux density can be obtained.

  C element is an element responsible for forming an amorphous phase and may not necessarily be included. However, by combining Si element, B element, P element, etc., the ability to form an amorphous phase and the stability of fine crystals Can be increased. Further, since C is inexpensive, the total material cost is reduced by the addition of C. However, in order to prevent the alloy composition from becoming brittle and lowering the magnetic properties, the proportion of C is preferably 10 at% or less. Further, 4 at% or less is more desirable in order to suppress variation in composition due to evaporation of C during melting of the alloy composition.

  Cu element is an essential element contributing to fine crystallization. Since fine crystallization is difficult, the proportion of Cu is preferably 0.4 at% or more. In addition, when the amount of Cu is excessive, the ability to form an amorphous phase is lowered, so 2 at% or less is desirable. Moreover, since a homogeneous fine crystal structure is obtained and magnetic characteristics are improved, 1.4 at% or less is more desirable, and 1.1 at% or less is more desirable in consideration of embrittlement and oxidation of the alloy composition.

  Further, there is a strong interatomic attractive force between P and Cu. Therefore, when the alloy composition contains a specific ratio of P and Cu, a cluster having a size of 10 nm or less is formed, and when the fine crystal is precipitated by this fine cluster, the α-Fe crystal is fine. Has a structure. In the present embodiment, the specific ratio (z / x) between the ratio (x) of P and the ratio (z) of Cu is preferably 0.06 or more and 1.20 or less. Outside this range, a homogeneous fine crystal structure cannot be obtained, and the alloy composition cannot have excellent magnetic properties. The specific ratio (z / x) is more preferably 0.08 or more and 0.55 or less in consideration of embrittlement and oxidation of the alloy composition.

  Further, in order to improve corrosion resistance, improve the ability to form an amorphous phase, and control grain growth, Fe, 3 at% or less of Ti, Zr, Hf, Nb, Ta, Mo, W, Cr, Co, Ni, One or more elements of Al, Mn, Zn, Sn, As, Sb, Bi, Y, N, O, Ca, V, Ma, rare earth elements and noble metal elements may be substituted. Furthermore, in order to control the saturation magnetic flux density and magnetostriction, 30 at% or less of Fe may be replaced with Co or Ni as magnetic elements.

  Here, the soft magnetic ribbon having an amorphous structure is characterized by embrittlement by heat treatment. Therefore, it becomes very difficult to produce a magnetic core by winding a soft magnetic ribbon that has been completely crystallized and embrittled. Moreover, since it breaks when a large tension is applied, the tension at the time of winding cannot be increased, and the space factor of the magnetic core decreases. Furthermore, there is a problem that sufficient magnetic properties cannot be obtained due to stress.

  In the present invention, by using a partially crystalline ribbon that leaves an amorphous phase, the ribbon becomes relatively tough and the magnetic core can be easily formed. In addition, since the soft magnetic ribbon reinforces the strength of the partial crystal ribbon by laminating with the soft magnetic ribbon, sufficient tension is applied when the soft magnetic ribbon and the partial crystal ribbon are wound together. Therefore, a laminated core having a high space factor can be obtained.

  The ratio of the soft magnetic ribbon to the partial crystal ribbon is such that the partial crystal ribbon has one or more layers for one soft magnetic ribbon in order to reduce the amount of self-heating and improve the heat dissipation associated with the heat treatment. desirable. Further, if the ratio of the embrittled partial crystal ribbon is too large, the mechanical strength is insufficient, and it becomes difficult to produce a laminated core having a high space factor. The crystal ribbon is desirably 10 layers or less, and more desirably 7 layers or less because the tension during winding can be further increased.

  Further, in order to suppress a decrease in the saturation magnetic flux density of the laminated magnetic core, the space factor of the laminated magnetic core is desirably 80% or more.

  In addition, the crystallization rate of the partial crystal ribbon is desirably 0.05 or more and 0.95 or less because the self-heating value is reduced and embrittlement that can produce a laminated magnetic core is suppressed, and the self-heating value is further reduced. In order to make the partial crystal ribbon more tough, 0.10 or more and 0.80 or less are more desirable. Further, in order to make the magnetic core easier to manufacture and increase the tension at the time of winding to obtain a laminated magnetic core having a high space factor, 0.25 or less is more desirable. Here, the crystallization rate of the present invention indicates the rate of precipitation of α-Fe crystals that can be precipitated, and indicates the rate of increase in saturation magnetization using a sample vibration magnetometer (VSM). .

  In order to obtain excellent magnetic properties in the present invention, it is desirable that the average particle size in the precipitated crystals after the heat treatment is 25 nm or less (excluding 0), and further 20 nm or less (excluding 0). If it is, better magnetic properties can be obtained.

  In the present invention, the thickness of the soft magnetic ribbon and the partial crystal ribbon is not particularly limited, but is preferably 100 μm or less (excluding 0) in consideration of the production of the soft magnetic ribbon and the partial crystal ribbon. In order to obtain excellent magnetic properties, 50 μm or less (not including 0) is more desirable. Furthermore, considering the ease of mass production, 35 μm or less (not including 0) is desirable.

Example 1
Industrial iron, Fe-B alloy, Fe-P alloy and electrolytic copper were used as raw materials. These raw materials were weighed so as to have a composition formula of Fe _84.3 B _6.0 P _9.0 Cu _0.7 , dissolved by high-frequency dissolution, and then 30 mm wide and 25 μm thick using a single roll quenching method. A continuous ribbon was prepared. This continuous ribbon was confirmed to be an amorphous single phase by an X-ray diffractometer. Further, it was confirmed by a differential scanning calorimeter that the first crystallization temperature was 410 ° C. and the second crystallization temperature was 505 ° C.

  Next, the produced continuous ribbon was cut to a width of 10 mm with a cutter to obtain a soft magnetic ribbon. The soft magnetic ribbon obtained in the same manner was heat-treated at a processing temperature of 440 ° C. and a processing time of 10 seconds to obtain a partially crystalline ribbon with an amorphous phase remaining inside the soft magnetic ribbon. The crystallization rate of the partial crystal ribbon was about 0.55.

  The produced soft magnetic ribbon and partial crystal ribbon were cut to a length of 120 cm. Next, one layer of the soft magnetic ribbon and one layer of the partial crystal ribbon were overlapped and wound to produce a laminated magnetic body having an outer diameter of 20.0 mm, an inner diameter of 17.5 mm, a height of 10.0 mm, and a weight of 4 g. The space factor of this laminated magnetic body was 82%. Thereafter, the laminated magnetic body was subjected to heat treatment set at a treatment temperature of 430 ° C. and a treatment time of 10 minutes to produce a laminated magnetic core.

  From the obtained laminated magnetic core, a sample was obtained by sampling a portion which was a soft magnetic ribbon and a portion which was a partial crystal ribbon. As a result of confirming the crystal precipitation state of this sample with an X-ray diffractometer, only the α-Fe crystal peak was found in both the sample that was a soft magnetic ribbon and the sample that was a partial crystal ribbon. It was confirmed that there was no peak of compounds such as Fe-B and Fe-P.

(Example 2)
In Example 2, the soft magnetic ribbon and the partial crystal ribbon were obtained in the same manner as in Example 1, and then cut into a length of 60 cm. Next, the soft magnetic ribbon 1 layer and the partial crystal ribbon 4 layers were overlapped and wound to produce a laminated magnetic body having an outer diameter of 20.0 mm, an inner diameter of 17.0 mm, a height of 10.0 mm, and a weight of 5 g. The space factor of this laminated magnetic body was 81%. Thereafter, the laminated magnetic body was subjected to heat treatment set at a treatment temperature of 435 ° C. and a treatment time of 10 minutes to produce a laminated magnetic core.

  A sample obtained in the same manner as in Example 1 from the obtained laminated magnetic core was checked for the crystal precipitation state by an X-ray diffractometer. As a result, the sample of the portion that was a soft magnetic ribbon and the partial crystal ribbon were found. In both of the samples, only the α-Fe crystal peak was confirmed, and it was confirmed that there was no peak of compounds such as Fe—B and Fe—P.

(Example 3)
In Example 3, a soft magnetic ribbon and a partial crystal ribbon were obtained in the same manner as in Example 1, and then cut into a length of 63 cm. Next, one layer of soft magnetic ribbon and 10 layers of partially crystalline ribbon are overlapped and wound to produce a laminated magnetic body having an outer diameter of 25.0 mm, an inner diameter of 19.5 mm, a height of 10.0 mm, and a weight of 11.7 g. did. The space factor of this laminated magnetic body was 82%. Thereafter, the laminated magnetic body was heat treated in the same manner as in Example 1 to produce a laminated magnetic core.

  A sample obtained in the same manner as in Example 1 from the obtained laminated magnetic core was checked for the crystal precipitation state by an X-ray diffractometer. As a result, the sample of the portion that was a soft magnetic ribbon and the partial crystal ribbon were found. In both of the samples, only the α-Fe crystal peak was confirmed, and it was confirmed that there was no peak of compounds such as Fe—B and Fe—P.

(Examples 4 to 6)
In Examples 4 to 6, the raw materials were weighed so as to have the composition formulas of Examples 4 to 6 in Table 1, respectively, and then a soft magnetic ribbon and a partial crystal ribbon were obtained in the same manner as in Example 1. The crystallization ratios of the partial crystal ribbons were the values shown in Examples 4 to 6 in Table 1, respectively.

  The produced soft magnetic ribbon 1 layer and the partial crystal ribbon 1 layer were overlapped and wound to produce a laminated magnetic body having an outer diameter of 20.0 mm, an inner diameter of 17.5 mm, and a height of 10.0 mm. Thereafter, the laminated magnetic body was subjected to heat treatment set at a treatment temperature of 430 ° C. and a treatment time of 10 minutes to produce a laminated magnetic core.

  A sample obtained from the obtained laminated magnetic core in the same manner as in Example 1 was confirmed by the X-ray diffractometer to confirm the crystal precipitation state. As a result, the sample was a soft magnetic ribbon and a partial crystal ribbon. It was confirmed that only the α-Fe crystal peak was observed in some of the samples, and there was no peak of compounds such as Fe-B and Fe-P.

(Comparative Example 1)
In Comparative Example 1, after obtaining a soft magnetic ribbon in the same manner as in Example 1, it was cut into a length of 300 cm, and a magnetic core having an outer diameter of 20.0 mm, an inner diameter of 17.5 mm, a height of 10.0 mm, and a weight of 4 g was obtained. Produced. The space factor of this magnetic core was 84%. Thereafter, the prepared magnetic core was subjected to heat treatment set at a processing temperature of 430 ° C. and a processing time of 10 minutes.

  A sample sampled from the magnetic core after the heat treatment was checked for the crystal precipitation state with an X-ray diffractometer, and it was confirmed that the Fe-B compound was precipitated in addition to the α-Fe crystal peak. It was.

(Comparative Example 2)
In Comparative Example 2, after the raw materials were weighed so that the composition formula Fe _83.3 Si _4.0 B _8.0 P _4.0 Cu _0.7 , a magnetic core was prepared in the same manner as in Comparative Example 1, and heat treatment was performed. went. From the magnetic core after the heat treatment, when the crystal precipitation state of the sampled sample was confirmed with an X-ray diffractometer, it was confirmed that the Fe—B compound was precipitated in addition to the α-Fe crystal peak. did it.

  Table 1 shows the results of measuring the magnetic permeability of the laminated magnetic cores obtained in this example and the comparative example, and the results of calculating the average particle size in the precipitated crystals using a transmission electron microscope (TEM).

  As is clear from Table 1, the laminated magnetic cores of Examples 1 to 6 have a high magnetic permeability and excellent magnetic characteristics. The average grain size of the portion that was the partial crystal ribbon was smaller than the average grain size of the portion that was the soft magnetic ribbon, and even in the soft magnetic ribbon having the larger average particle size, fine α-Fe crystals It was confirmed that was deposited.

  On the other hand, the magnetic cores of Comparative Examples 1 and 2 obtained only low magnetic permeability. Moreover, the average particle diameters in the precipitated crystals were 27.0 nm and 30.5 nm, respectively, confirming the coarsening of the crystals. As a result, since the magnetic core is composed entirely of soft magnetic ribbons with no crystals precipitated, the amount of self-heat generation accompanying fine crystal precipitation increases, and the heat dissipation amount is higher than in Examples 1-6. Therefore, it is considered that the excessive temperature rise due to self-heating occurs and the core temperature rises to the vicinity of the second crystallization temperature. As a result, the magnetic properties were significantly reduced.

  As described above, a laminated magnetic core is formed by laminating a soft magnetic ribbon made of an Fe-based amorphous alloy and a partial crystal ribbon that leaves an amorphous phase inside the soft magnetic ribbon made of an Fe-based amorphous alloy. As a result, it was possible to obtain a laminated magnetic body, a laminated magnetic core and a method for producing the same, which suppresses the precipitation of the compound and has excellent magnetic properties.

  As mentioned above, although the Example of this invention was described, this invention is not limited above, The change and correction of a structure are possible in the range which does not deviate from the summary of this invention. For example, an example of an embodiment according to the present invention is a laminated magnetic core in which a soft magnetic ribbon and a partial crystal ribbon are overlapped and wound, and the soft magnetic ribbon and the partial crystal ribbon are punched into a desired shape, A laminated magnetic core obtained by laminating them may be used. That is, any magnetic core in which soft magnetic ribbons and partial crystal ribbons are laminated may be used, and is not particularly limited. That is, it is a matter of course that various modifications and corrections that can be made by those skilled in the art are also included in the present invention.

DESCRIPTION OF SYMBOLS 1 Laminated magnetic core 2 Magnetic core 11, 21 Soft magnetic ribbon 12 Partial crystal ribbon 22 Inner 23 Outer 24 Inner 31 1st crystallization temperature 32 2nd crystallization temperature

Claims (6)

A laminated magnetic core in which at least two layers of soft magnetic ribbons represented by the same composition formula are laminated, and one soft magnetic ribbon has one layer, and the other soft magnetic ribbon has one or more layers. layer stacked below stacked magnetic core having an average particle size in the one soft magnetic ribbon of fine crystals, being greater than the average grain size in the fine crystal of the other soft magnetic ribbon. 2. The laminated magnetic core according to claim 1, wherein a space factor of the laminated magnetic core is 80% or more. 3. The laminated magnetic core according to claim 1, wherein an average grain size in the fine crystal is 25 nm or less. An amorphous single-phase soft magnetic ribbon made of an Fe-based alloy and a partial crystal ribbon that leaves an amorphous phase inside the soft-magnetic ribbon made of an Fe-based alloy are laminated , A laminated magnetic body having a crystallization rate of 0.05 or more and 0.25 or less . 5. The laminated magnetic body according to claim 4 , wherein one layer or more and 10 or less of the partial crystal ribbons are laminated with respect to one layer of the soft magnetic ribbon. A step of producing an amorphous single-phase soft magnetic ribbon made of an Fe-based alloy, a step of producing a partial crystal ribbon that leaves an amorphous phase inside the soft-magnetic ribbon made of an Fe-based alloy, and The method of manufacturing a laminated magnetic core according to any one of claims 1 to 3, further comprising a step of laminating the soft magnetic ribbon and the partial crystal ribbon and heat-treating them.

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