Thin nanocrystal alloy band production method, and thin nanocrystal alloy band

Abstract

Provided is a thin nanocrystal alloy band production method with which it is possible to obtain, in a highly productive manner, a thin nanocrystal alloy band having excellent magnetic characteristics and isotropy. A method for producing a thin nanocrystal alloy band represented by a composition formula (Fe1-xAx)aSibBcCudMe, where A represents at least one of Ni and Co, M represents at least one selected from Nb, Mo, V, Zr, Hf, and W, and, 80.0≤a≤87.0, 0≤b≤9.0, 12.0≤c≤16.0, 0≤d≤1.5, 0≤e≤1.5, and 0≤x≤0.1 are satisfied in terms of atom%, the method comprising transporting a thin amorphous alloy band while pressing the thin amorphous alloy band against a heating body so as to be heat the same, wherein the heating body is heated to a heating temperature Ta of Tx1+80°C to Tx1+160°C when Tx1°C represents a bcc-Fe crystallization onset temperature as measured when the temperature increase rate of the thin amorphous alloy band is set to 20 K / min.

Description

Nanocrystalline alloy ribbon manufacturing method and nanocrystalline alloy ribbon

[0001] The present disclosure relates to a method for producing a nanocrystalline alloy ribbon having a nanocrystalline structure, and to a nanocrystalline alloy ribbon.

[0002] Nanocrystalline alloy ribbons having a nanocrystalline structure exhibit excellent magnetic properties and are used in transformers, electronic components, motors, and the like. These transformers, electronic components, motors, and the like are required to be smaller and more efficient. To this end, further improvements in the properties of nanocrystalline alloys used in the magnetic cores of these components (transformers, electronic components, motors, and the like) are required. Required properties of such nanocrystalline alloys include high saturation magnetic flux density and low core loss. As semiconductors and other devices become increasingly high-frequency, efforts are being made to increase the operating frequency and reduce the size of these components. Fe-based amorphous alloys and Fe-based nanocrystalline alloys, which have low core loss, have attracted attention. To promote their commercial adoption, soft magnetic alloys with excellent cost, productivity, and heat treatability are required.

[0003] It is known that Fe-based nanocrystalline alloy ribbons can achieve both high saturation magnetic flux density and low coercive force and iron loss by heat-treating them at a very fast heating rate.Known heat-treating methods that achieve a fast heating rate include contacting the ribbon with a heated plate and sandwiching the ribbon between heated plates.

[0004] In Patent Document 1, the composition formula is Fe １００－ａ－ｂ－ｃ B ａ Cu ｂ M' ｃ The publication describes a method for producing a soft magnetic material that achieves both high saturation magnetization and low coercive force by heating an alloy having a composition that satisfies 10≦a≦16, 0<b≦2, and 0≦c≦8 and that has an amorphous phase at a heating rate of 10°C / sec or more and holding the temperature at a temperature above the crystallization start temperature and below the temperature at which an Fe-B compound is generated for 0 to 80 seconds.

[0005] In Patent Document 2, the composition formula is Fe100-abc-dB ａ Si ｂ Cu ｃ Mｄ where a, b, c, and d are all atomic percents and satisfy 0<a, 0<b, 0<c, 0≦d, and 78≦100-a-b-c-d, respectively, and M represents at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. The amorphous alloy ribbon is continuously run while being subjected to tension F, and a partial region of the continuously running amorphous alloy ribbon while being subjected to tension F is brought into contact with a heat transfer medium maintained at a temperature of 450°C or higher, thereby raising the temperature of the amorphous alloy ribbon to a target temperature of 450°C or higher at an average heating rate of 10°C / second or higher in the temperature range from 350°C to 450°C.

[0006] International Publication No. 2018 / 025931 International Publication No. 2017 / 150440

[0007] The method described in Patent Document 1 discloses a method of sandwiching a ribbon between heated plates. This method can obtain good isotropic properties and suppress the occurrence of wrinkles and streaks. However, the series of heat treatment steps of inserting the ribbon, sandwiching it between heating bodies, and removing it takes time. Furthermore, since the amount that can be treated at one time is limited, this method is not suitable for heat treating a large amount of ribbons in mass production. Furthermore, since the soft magnetic material described in Patent Document 1 does not contain Si, it does not contain SiO, which contributes to the corrosion resistance of the soft magnetic material. ２ No film is formed on the surface of the material, making it difficult to prevent rust and other problems.

[0008] Patent Document 2 discloses a method in which a ribbon is brought into contact with a heated plate. Because the ribbon can be heat-treated while being transported, mass production is highly feasible. Furthermore, good magnetic properties can also be obtained. However, although tension is applied to the ribbon to bring the ribbon into uniform contact with the heating plate, some ingenuity is required to maintain uniform contact of the moving ribbon with the heating plate. Furthermore, because only one side of the ribbon is in contact with the heating plate while being transported, and the side opposite to the side in contact with the heating plate is not constrained, there is a risk that the generation of wrinkles or streaks due to crystallization when contacting the heating plate or partial lifting of the ribbon cannot be suppressed.

[0009] Furthermore, nanocrystalline alloy ribbons are produced by ejecting a molten alloy adjusted to a predetermined alloy composition onto a rotating chill roll, rapidly solidifying the alloy, and then heat-treating the alloy ribbon. The nanocrystalline alloy ribbon is produced as a thin, long ribbon with a predetermined width. This production method easily introduces anisotropy in the casting direction (longitudinal direction), and even after heat treatment, the magnetic properties tend to differ between the longitudinal direction and the width direction perpendicular to the longitudinal direction.

[0010] For example, nanocrystalline alloy ribbons used in motors, etc., are required to have as isotropic properties as possible. However, as described above, it has been difficult to obtain a nanocrystalline alloy ribbon that has excellent magnetic properties (high saturation magnetic flux density, low iron loss) and isotropy by a highly productive method.

[0011] An object of the present disclosure is to provide a nanocrystalline alloy ribbon having excellent magnetic properties and isotropy, a nanocrystalline alloy ribbon in which wrinkles or streaks are suppressed and which achieves a high space factor, and a method for manufacturing a nanocrystalline alloy ribbon that can achieve these by a highly productive method.Another object is to provide a nanocrystalline alloy ribbon obtained by the method that has excellent magnetic properties and isotropy, and a nanocrystalline alloy ribbon in which wrinkles or streaks are suppressed and which achieves a high space factor.

[0012] The present disclosure has the following features: <1> A method for producing a nanocrystalline alloy ribbon having a structure in which crystal grains having an average grain size of 30 nm or less exist in an amorphous phase by bringing an amorphous alloy ribbon into contact with a heater and heating the amorphous alloy ribbon, wherein the nanocrystalline alloy ribbon has a composition formula (Fe １－ｘ A ｘ ) ａ Si ｂ B ｃ Cu ｄ M ｅwherein A is at least one of Ni and Co, M is at least one selected from Nb, Mo, V, Zr, Hf, and W, and the atomic percentages are 80.0≦a≦87.0, 0≦b≦9.0, 12.0≦c≦16.0, 0≦d≦1.5, 0≦e≦1.5, and 0≦x≦0.1, and when the amorphous alloy ribbon is heated by bringing the amorphous alloy ribbon into contact with the heating body, the amorphous alloy ribbon is conveyed while a ribbon pressing member is brought into contact with a surface of the amorphous alloy ribbon opposite to a surface of the amorphous alloy ribbon that is in contact with the heating body, and the amorphous alloy ribbon is heated in a state sandwiched between the heating body and the ribbon pressing member, A method for producing a nanocrystalline alloy ribbon, wherein the heating body is heated to a heating temperature Ta of not less than Tx1 + 80°C and not more than Tx1 + 160°C, where Tx1°C is the bccFe crystallization onset temperature of the amorphous alloy ribbon measured at a heating rate of 20 K / min. <2> A method for producing a nanocrystalline alloy ribbon according to <1>, wherein the ribbon pressing member is a flexible member. <3> A method for producing a nanocrystalline alloy ribbon according to <1> or <2>, wherein, when the amorphous alloy ribbon is heated by contacting the amorphous alloy ribbon with the heating body, the heating rate of the amorphous alloy ribbon is 50°C / sec to 4000°C / sec. <4> A method for producing a nanocrystalline alloy ribbon according to any one of <1> to <3>, wherein, when the amorphous alloy ribbon is heated by contacting the amorphous alloy ribbon with the heating body, the conveying speed of the amorphous alloy ribbon is 1 m / min or more. <5> The method for producing a nanocrystalline alloy ribbon according to any one of <1> to <4>, wherein when the amorphous alloy ribbon is brought into contact with the heating body and heated, the contact time of the amorphous alloy ribbon with the heating body is 0.1 to 30 seconds. <6> The method for producing a nanocrystalline alloy ribbon according to any one of <1> to <5>, wherein, when an FeB precipitation start temperature measured at a heating rate of 20 K / min is Tx2°C, the maximum temperature of the amorphous alloy ribbon heated in contact with the heating body is controlled to Tx2 + 160°C or less. <7> The method for producing a nanocrystalline alloy ribbon according to any one of <1> to <6>, wherein, in the composition formula, 82.0≦a≦86.5, 0.01≦b≦3.0, 13.0≦c≦15.0, 0.01≦d≦1.5, and 0≦e≦1.5.<8> The method for producing a nanocrystalline alloy ribbon according to any one of <1> to <7>, wherein the amorphous alloy ribbon is heated while being pressed by the heating body or the ribbon pressing member, and a pressure pressing the amorphous alloy ribbon against the heating body is 0.03 MPa or more. <9> The method for producing a nanocrystalline alloy ribbon according to any one of <1> to <8>, wherein a wrinkle height on the surface of the nanocrystalline alloy ribbon is 0.15 mm or less and a space factor is 84.0% or more. <10> The method for producing a nanocrystalline alloy ribbon according to any one of <1> to <9>, wherein the nanocrystalline alloy ribbon has a saturation magnetic flux density Bs of 1.75 T or more. <11> A magnetic flux density B80 when a magnetic field of 80 A / m is applied in the longitudinal direction of the nanocrystalline alloy ribbon. Ｌ and a magnetic flux density B80 when a magnetic field of 80 A / m is applied in the width direction perpendicular to the longitudinal direction. Ｗ and the ratio (B80 Ｌ / B80 Ｗ ) is 0.80 to 1.20, and B80 Ｌ , B80 Ｗ <12> The method for producing a nanocrystalline alloy ribbon according to any one of <1> to <11>, wherein the nanocrystalline alloy ribbon has a coercive force Hc of 25 A / m or less, an iron loss (1 T, 1 kHz) of 15 W / kg or less, and a saturation magnetostriction of 20 ppm or less. <13> The method for producing a nanocrystalline alloy ribbon according to any one of <1> to <12>, wherein the amorphous alloy ribbon has a thickness of 20 μm or more and a width of 10 mm or more. <14> A nanocrystalline alloy ribbon having a structure in which crystal grains having an average grain size of 30 nm or less exist in an amorphous phase, the nanocrystalline alloy ribbon having a composition formula (Fe １－ｘ A ｘ ) ａ Si ｂ B ｃ Cu ｄ M ｅwherein A is at least one of Ni and Co, M is at least one selected from Nb, Mo, V, Zr, Hf, and W, and the atomic percentages are 80.0≦a≦87.0, 0≦b≦9.0, 12.0≦c≦16.0, 0≦d≦1.5, 0≦e≦1.5, and 0≦x≦0.1; the saturation magnetic flux density Bs is 1.75 T or more; and the magnetic flux density B80 when a magnetic field of 80 A / m is applied in the longitudinal direction of the nanocrystalline alloy ribbon is 1.75 T or more. Ｌ and a magnetic flux density B80 when a magnetic field of 80 A / m is applied in the width direction perpendicular to the longitudinal direction. Ｗ and the ratio (B80 Ｌ / B80 Ｗ ) is 0.80 to 1.20, and B80 Ｌ , B80 Ｗ a nanocrystalline alloy ribbon, each of which has a magnetic field strength of 1.0 T or more. <15> The nanocrystalline alloy ribbon according to <14>, wherein, in the composition formula, 82.0≦a≦86.5, 0.01≦b≦3.0, 13.0≦c≦15.0, 0.01≦d≦1.5, and 0≦e≦1.5. <16> The nanocrystalline alloy ribbon according to <14> or <15>, wherein a wrinkle height on the surface of the nanocrystalline alloy ribbon is 0.15 mm or less, and a space factor is 84.0% or more. <17> The nanocrystalline alloy ribbon according to any one of <14> to <16>, wherein a coercive force Hc is 25 A / m or less, an iron loss (1 T, 1 kHz) is 15 W / kg or less, and a saturation magnetostriction is 20 ppm or less. <18> The nanocrystalline alloy ribbon according to any one of <14> to <17>, wherein a thickness is 20 μm or more and a width is 10 mm or more.

[0013] According to the present disclosure, it is possible to provide a method for manufacturing a nanocrystalline alloy ribbon that can be obtained, by a highly productive method, a nanocrystalline alloy ribbon having excellent magnetic properties and isotropy, and that is suppressed in terms of wrinkles, streaks, etc. and achieves a high space factor. Furthermore, it is possible to provide a nanocrystalline alloy ribbon obtained by the method that has excellent magnetic properties and isotropy, and that is suppressed in terms of wrinkles, streaks, etc. and achieves a high space factor.

[0014] FIG. 1 is a conceptual diagram showing one embodiment of the heat treatment method of the present disclosure. FIG. 2 is a conceptual diagram showing another embodiment of the heat treatment method of the present disclosure. FIG. 3 is a conceptual diagram showing another embodiment of the heat treatment method of the present disclosure. FIG. 4 is a laser microscope photograph showing an evaluation of the wrinkle height of an amorphous alloy ribbon of sample No. 4 of the present disclosure before heat treatment. FIG. 5 is a laser microscope photograph showing an evaluation of the wrinkle height of sample No. 8 of the present disclosure. FIG. 6 is a laser microscope photograph showing an evaluation of the wrinkle height of sample No. 9 of the present disclosure. FIG. 7 is a laser microscope photograph showing an evaluation of the wrinkle height of sample No. 4 of the present disclosure. FIG. 8 is an example of a temperature profile during heat treatment of the present disclosure.

[0015] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present disclosure.

[0016] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​described before and after "to" as the lower and upper limits, respectively. In the numerical ranges described in stages in the present disclosure, the upper or lower limit described in a certain numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in the present disclosure, the upper or lower limit described in a certain numerical range may be replaced with a value shown in the examples. In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.

[0017] The nanocrystalline alloy ribbon of the present disclosure has a composition formula (Fe １－ｘ A ｘ ) ａ Si ｂ B ｃ Cu ｄ M ｅ wherein A is at least one of Ni and Co, M is at least one selected from Nb, Mo, V, Zr, Hf, and W, and the atomic percentages are 80.0≦a≦87.0, 0≦b≦9.0, 12.0≦c≦16.0, 0≦d≦1.5, 0≦e≦1.5, and 0≦x≦0.1.

[0018] The composition of the nanocrystalline alloy ribbon of the present disclosure will be described in detail below. The Fe (iron) content is 80.0% or more and 87.0% or less in atomic percent. By setting the Fe content to 80.0% or more, a high saturation magnetic flux density can be obtained. The Fe content is preferably 81% or more, more preferably 82.0% or more, even more preferably 82.5% or more, even more preferably 83% or more, even more preferably 83.5% or more, and even more preferably 84% or more. Furthermore, since it becomes difficult to form an amorphous structure when the Fe content exceeds 87.0%, the Fe content is set to 87.0% or less. The Fe content is preferably 86.5% or less, and even more preferably 86% or less.

[0019] In addition, a part of Fe may be substituted with at least one element selected from Ni and Co. (Fe １－ｘ A ｘ ), A is at least one of Ni and Co, and x is 0.1 or less. Substituting a portion of Fe with element A is optional, and x may be 0. A small amount of Ni has the effect of suppressing crystal grain growth and reducing coercivity. However, if x exceeds 0.1, the effect is reduced and the saturation magnetic flux density is significantly reduced. Preferably, x is 0.05 or less, and more preferably, 0.03 or less. Co has the effect of increasing the saturation magnetic flux density by substituting Fe, but is very expensive and increases coercivity and iron loss, so it is best to use 0.1 or less, preferably 0.05 or less, and more preferably, 0.03 or less.

[0020] When a part of Fe is substituted with at least one element of Ni and Co, (Fe １－ｘ A ｘ ) ａ The value a in this formula is in the same range as the above-mentioned range of Fe, 80.0% or more and 87.0% or less (80.0≦a≦87.0). It is preferably 81% or more, more preferably 82.0% or more, even more preferably 82.5% or more, even more preferably 83% or more, even more preferably 83.5% or more, and even more preferably 84% or more. It is also preferably 86.5% or less, even more preferably 86% or less.

[0021] The content of Si (silicon) is 0% or more and 9.0% or less in atomic percent. The content of Si may be 0%. By including Si, a SiO layer of several tens of nanometers thick is formed on the surface of the alloy. ２ An oxide film of Si can be formed. This can improve the corrosion resistance of the nanocrystalline alloy ribbon. In order to obtain this effect of improving corrosion resistance, it is preferable that Si is contained in an amount of 0.01% or more. Furthermore, it is more preferable that it is contained in an amount of 0.15% or more, and it is even more preferable that it is contained in an amount of 1.0% or more. If the Si content exceeds 9.0%, it becomes difficult to obtain a high saturation magnetic flux density, and it also becomes difficult to increase the plate thickness of the alloy ribbon. For this reason, the Si content is set to 9.0% or less. It is preferably 5.0% or less, more preferably 4% or less, further preferably 3.0% or less, and even more preferably 2% or less.

[0022] The content of B (boron) is 12.0% or more and 16.0% or less in atomic percent. If the B content is less than 12.0%, it becomes difficult to form an amorphous phase, so the B content is set to 12.0% or more. Preferably, it is 12.5% ​​or more, more preferably 13.0% or more, and even more preferably 13.5% or more. If the B content exceeds 16.0%, the difference between the bccFe (αFe) crystallization onset temperature and the FeB precipitation onset temperature becomes small, narrowing the temperature range in which heat treatment is possible. A narrower temperature range in which heat treatment is possible is likely to affect productivity. Therefore, the B content is set to 16.0% or less. Preferably, it is 15.0% or less, more preferably 14.5% or less, and even more preferably 14.4% or less.

[0023] The content of Cu (copper) is 0% or more and 1.5% or less in atomic percent. The Cu content may be 0%, but adding Cu makes it easier to obtain a uniform and fine nanocrystalline structure. In particular, adding Cu is preferable to achieve low iron loss. For this reason, the Cu content is preferably 0.01% or more. More preferably, it is 0.05% or more, and even more preferably, it is 0.1% or more. It may further be 0.2% or more, or 0.4% or more, or 0.5% or more. If the Cu content exceeds 1.5%, the soft magnetic alloy ribbon becomes easily embrittled, making it difficult to increase the thickness of the ribbon. For this reason, the Cu content is set to 1.5% or less. It is preferably 1.0% or less, and even more preferably, it is 0.9% or less. It may further be 0.85% or less, or 0.7% or less, or 0.6% or less.

[0024] The M element is at least one element selected from Nb, Mo, V, Zr, Hf, and W, and is present in an atomic percentage range of 0% to 1.5%. While the M element may be 0%, the inclusion of the M element can shift the precipitation start temperature of FeB compounds, which significantly degrade soft magnetic properties, to a higher temperature. This widens the difference between the bccFe (αFe) crystallization start temperature and the FeB precipitation start temperature, broadening the optimal heat treatment temperature range and easing the heat treatment conditions. The M element is preferably present in an amount of 0.1% or more, and more preferably in an amount of 0.15% or more. The M element is expensive, which increases the price. Therefore, a lower content is preferable. Therefore, the M element content is set to 1.5% or less. It is preferably present in an amount of 1.0% or less, and even more preferably in an amount of 0.9% or less. It may also be present in an amount of 0.8% or less, 0.7% or less, or 0.6% or less. The M element content is also preferably less than 0.4%, more preferably 0.3% or less, and even more preferably 0.25% or less.

[0025] The nanocrystalline alloy ribbon of the present disclosure may contain C (carbon). The C content is preferably 1% by mass or less. The inclusion of C improves the fluidity of the molten metal (reducing the viscosity of the molten metal), improves adhesion to the chill roll, and is expected to contribute to surface smoothing of the alloy ribbon. Furthermore, C is likely to segregate on the surface of the alloy ribbon, and when it diffuses to the surface during heat treatment, it is expected to promote structural relaxation and improve the squareness of the DC BH curve. Furthermore, when C is contained, it is preferably 0.03% by mass or more.

[0026] The nanocrystalline alloy ribbon of the present disclosure may contain impurities other than the elements described above. Examples of impurities include S (sulfur), O (oxygen), N (nitrogen), Cr, Mn, P, Ti, and Al. For example, the S content is preferably 200 mass ppm or less, the O content is preferably 5000 mass ppm or less, the N content is preferably 1000 mass ppm or less, the Ti content is preferably 1000 mass ppm or less, and the Al content is preferably 1000 mass ppm or less. The total content of these impurities is preferably 0.5 mass% or less. Furthermore, elements corresponding to the impurities may be added as long as they are within the above ranges.

[0027] A method for producing a nanocrystalline alloy ribbon according to the present disclosure will be described. The nanocrystalline alloy ribbon according to the present disclosure can be obtained by ejecting a molten alloy having the above-described alloy composition onto a rotating chill roll, rapidly solidifying the alloy ribbon on the chill roll, and heat-treating the alloy ribbon. The alloy ribbon obtained by rapidly solidifying the molten alloy has an amorphous alloy structure, becoming an amorphous alloy ribbon. The nanocrystalline alloy ribbon can be obtained by heat-treating this amorphous alloy ribbon. Note that the amorphous alloy ribbon obtained by rapidly solidifying the molten alloy may contain a crystalline phase consisting of fine crystals.

[0028] The molten alloy can be prepared by blending the element sources (pure iron, ferroboron, ferrosilicon, etc.) that will result in the desired alloy composition, heating them in an induction heating furnace, and melting them above their melting points. The molten alloy is ejected onto a rotating chill roll from a slit-shaped nozzle of a predetermined shape, and the molten alloy is rapidly solidified on the chill roll to obtain an alloy ribbon. The chill roll can have an outer diameter of 350 to 1,000 mm, a width of 100 to 400 mm, and a peripheral speed of rotation of 20 to 35 m / s. The chill roll is internally equipped with a cooling mechanism (e.g., water cooling) to suppress temperature increases at the outer periphery. The outer periphery of the chill roll is preferably made of a Cu alloy with a thermal conductivity of 120 W / (m·K) or higher. By ensuring that the thermal conductivity of the outer periphery is 120 W / (m·K) or higher, the cooling rate of the molten alloy when cast into an alloy ribbon can be increased. This suppresses embrittlement of the alloy ribbon, enabling the alloy ribbon to be thickened, and also suppresses surface crystallization during casting, thereby suppressing coarsening of crystal grains during heat treatment and reducing iron loss.

[0029] The thermal conductivity of the outer periphery of the chill roll is preferably 150 W / (m K) or more, and more preferably 180 W / (m K) or more. In particular, when the thickness of the nanocrystalline alloy ribbon is 30 μm or more, the thermal conductivity of the outer periphery is preferably 150 W / (m K) or more. The outer periphery of the chill roll is the part that comes into contact with the molten alloy, and its thickness may be about 5 to 15 mm, and the inside thereof may be made of a structural material that maintains the roll structure.

[0030] The amorphous alloy ribbon produced by the above-described rapid cooling method is heat-treated to obtain a nanocrystalline alloy ribbon. The method for producing a nanocrystalline alloy ribbon according to the present disclosure is characterized by the heat treatment method.

[0031] The heat treatment method disclosed herein is a method for heating an amorphous alloy ribbon by contacting the amorphous alloy ribbon with a heating body. When the amorphous alloy ribbon is heated by contacting the amorphous alloy ribbon with the heating body, the amorphous alloy ribbon is conveyed while a ribbon presser member is in contact with the surface of the amorphous alloy ribbon opposite the surface that contacts the heating body, and the amorphous alloy ribbon is heated while being sandwiched between the heating body and the ribbon presser member. When the bccFe crystallization start temperature of the amorphous alloy ribbon measured at a heating rate of 20 K / min is Tx1°C, the heating temperature Ta of the heating body is set to a temperature of Tx1 + 80°C or higher and Tx1 + 160°C or lower. The heating rate of the amorphous alloy ribbon is preferably set to 50°C / sec to 4000°C / sec. Furthermore, the conveying speed of the amorphous alloy ribbon is preferably 1 m / min or higher.

[0032] In the present disclosure, a flexible member may be pressed against the surface of the amorphous alloy ribbon opposite to the surface that contacts the heating body, so as to press the amorphous alloy ribbon against the heating body. The flexible member is preferably a metal member. The ribbon pressing member may also be a belt or a roll.

[0033] An example of the heat treatment method of the present disclosure will now be described. Fig. 1 is a conceptual diagram showing one embodiment of the heat treatment method of the present disclosure. The heat treatment method shown in Fig. 1 includes a heating roller 2 serving as a heating body, a metal ribbon pressure belt 3 (a metal ribbon pressure member), and rollers 4 and 5 supporting the metal ribbon pressure belt 3.

[0034] The heating roller 2 and the thin ribbon holding metal belt 3 (thin ribbon holding member) are arranged in a state where they can come into contact with each other, and the amorphous alloy thin ribbon 1 is heated while being sandwiched between the heating roller 2 (heating body) and the thin ribbon holding metal belt 3.

[0035] At this time, the amorphous alloy ribbon 1 is pressed against the heating body (heating roller 2) by the ribbon pressing metal belt 3 (ribbon pressing member). Note that the ribbon pressing metal belt 3 (ribbon pressing member) may be in a state where it presses the amorphous alloy ribbon 1 against the heating body (heating roller 2), or the heating body (heating roller 2) may be in a state where it presses the amorphous alloy ribbon 1 against the ribbon pressing metal belt 3 (ribbon pressing member). In the following, the description will be given assuming that the amorphous alloy ribbon 1 is pressed against the heating body (heating roller 2) by the ribbon pressing metal belt 3 (ribbon pressing member).

[0036] In FIG. 1 , arrows indicate the movement of each component, and the heating roller 2 and rollers 4 and 5 are configured to rotate. As a result, the amorphous alloy ribbon 1 (hereinafter also referred to as ribbon 1) is heated while being conveyed and pressed against the heating roller 2. It is preferable to use heating rollers that can also heat the rollers 4 and 5. This allows the ribbon presser metal belt 3 to be heated in advance. When the rollers 4 and 5 are heating rollers, it is preferable to set the temperature of the ribbon presser metal belt 3 (the temperature when it contacts the ribbon 1) to a temperature equal to or slightly lower than the heating temperature of the ribbon 1. The temperature of the rollers 4 and 5 may be set to a temperature that allows the ribbon presser metal belt 3 to be at an appropriate temperature. For example, it is also preferable to set the temperature of the rollers 4 and 5 to be about 50° C. higher than the temperature of the heater. The temperatures of the ribbon presser metal belt 3 and the rollers 4 and 5 can be selected to be appropriate for the heat treatment of the ribbon 1.

[0037] The ribbon presser metal belt 3 is an example of a flexible member, and the flexible member is preferably a metal member from the viewpoints of flexibility and strength. For example, it is more preferable to use a material with excellent heat resistance, such as heat-resistant stainless steel or a nickel-based super heat-resistant alloy. According to the above heat treatment method, a flexible member (ribbon presser metal belt 3) is pressed against the surface of the amorphous alloy ribbon 1 opposite the surface that contacts the heating body, thereby pressing the amorphous alloy ribbon 1 against the heating body (heating roller 2). Note that it is preferable that the amorphous alloy ribbon 1 is in close contact with the heating roller 2 by the ribbon presser metal belt 3, and that the amorphous alloy ribbon 1, ribbon presser metal belt 3, and heating roller 2 move as a single unit.

[0038] Here, the heating roller 2 is a heating element (heating element of the present disclosure) that directly contacts the amorphous alloy ribbon to heat it. The amorphous alloy ribbon 1 is heated by contacting a portion (a partial region in the circumferential direction) of the outer peripheral surface of the cylindrical heating roller 2. The heating roller 2 may be provided with a driving force for transporting the amorphous alloy ribbon. The roller for driving the ribbon presser metal belt 3 may be both rollers 4 and 5, or either one of them. The driving force may be provided to roller 5, with roller 4 being mechanically subordinate. This configuration avoids complex control, such as electrically synchronous operation of rollers 4 and 5, and also eliminates the need to correct synchronization errors due to differences in thermal expansion between rollers 4 and 5.

[0039] The heating roller 2 is an example of a heating body having a convex surface for contacting and heating the amorphous alloy ribbon. The "convex surface" means a surface that is raised toward the amorphous alloy ribbon, and may have any shape that allows the amorphous alloy ribbon to follow and ensure sufficient contact, such as a curved surface on the side of a cylindrical (cylinder) roller as shown in Fig. 1, or a curved surface formed as part of a member such as the curved surface of a semi-cylindrical member.

[0040] FIG. 2 is a conceptual diagram showing another embodiment of the heat treatment method of the present disclosure. The heat treatment method shown in FIG. 2 includes a heating roller 2 serving as a heating body, and ribbon pressure rollers 6, 7, and 8 serving as ribbon pressure members that press the amorphous alloy ribbon 1 against the heating roller 2 serving as a heating body. The ribbon 1 is passed between the heating roller 2 (heating body) and the ribbon pressure rollers 6, 7, and 8, and heated while being pressed against the heating body (heating roller 2). Arrows indicate the movement of each component, and the heating roller 2 and ribbon pressure rollers 6, 7, and 8 are configured to rotate. As a result, the amorphous alloy ribbon 1 is heated while being transported and pressed against the heating roller 2. It is preferable to use heating rollers that can also heat the ribbon pressure rollers 6, 7, and 8.

[0041] FIG. 3 is a conceptual diagram showing another embodiment of the heat treatment method of the present disclosure. In the heat treatment method shown in FIG. 3, a semicircular (half-cylindrical) heater 32 is used instead of the heating roller 2 of FIG. 1 , and a ribbon presser metal belt 33 and rollers 34 and 35 supporting the ribbon presser metal belt 33 are provided as means for pressing the amorphous alloy ribbon 1 against the heater 32. The ribbon 1 is passed between the heater 32 and the ribbon presser metal belt 33 (ribbon presser member), and is heated while being pressed against the heater 32. Arrows indicate the movement of each component, and the rollers 34 and 35 are configured to rotate. As a result, the amorphous alloy ribbon 1 is heated while being transported and pressed against the heater 32. Note that it is preferable to use a heating roller that can also heat the rollers 34 and 35. As a result, it is preferable to heat the ribbon presser metal belt 33 in advance.

[0042] As shown in Figures 1, 2, and 3, when an amorphous alloy ribbon is heated by contacting the amorphous alloy ribbon with a heater, the amorphous alloy ribbon can be heated while being sandwiched between the heater and the ribbon presser member while being conveyed. In this case, the heating rate of the amorphous alloy ribbon is preferably 50°C / sec to 4000°C / sec. When obtaining a nanocrystalline alloy ribbon by heat treatment, the heating rate to achieve a fine nanocrystalline structure varies depending on the composition. However, a composition with a low Cu content, a low M element content, and a high Fe content, which can achieve a high saturation magnetic flux density, requires a faster heating rate. For the compositions disclosed herein, the lower limit of the heating rate is 50°C / sec, and the upper limit is substantially about 4000°C / sec, although this can be determined depending on the capacity of the heat treatment equipment, the temperatures of the heater and ribbon presser member, and the contact state between the heater and ribbon presser member and the ribbon. The heating rate is preferably 500°C / sec or higher.

[0043] The heating body preferably has a width wider than that of the amorphous alloy ribbon. This allows the entire width of the ribbon to be in close contact with the heating body when the amorphous alloy ribbon is pressed against the heating body. When the amorphous alloy ribbon is pressed against the heating body and heated, the distance between the amorphous alloy ribbon and the heating body is preferably 50 mm or more in terms of the length of the heating body surface. The distance between the amorphous alloy ribbon and the heating body is more preferably 150 mm or more in terms of the length of the heating body surface. The conveying speed of the amorphous alloy ribbon is preferably 1 m / min or more. In mass production, the higher the conveying speed, the higher the production volume, so the conveying speed is more preferably 10 m / min or more. The contact time between the amorphous alloy ribbon and the heating body is preferably 0.1 to 30 seconds. The lower limit of the contact time is more preferably 0.2 seconds, and the upper limit of the contact time is more preferably 10 seconds, even more preferably 5 seconds, and most preferably 2 seconds. In order to improve mass productivity, when speeding up and stabilizing the process, it is preferable to set the time to 0.2 to 2 seconds.

[0044] When an amorphous alloy ribbon is heat-treated, the maximum temperature reached by the ribbon may be higher than the heater temperature due to self-heating caused by crystallization of the ribbon. If the temperature of the amorphous alloy ribbon becomes too high, desired magnetic properties cannot be obtained. Therefore, when the FeB precipitation start temperature measured at a heating rate of 20 K / min for the amorphous alloy ribbon is Tx2°C, it is preferable to control the ribbon temperature to Tx2+160°C or lower. The heating temperature Ta, conveying speed, etc. are set to enable this control. If the temperature exceeds Tx2+160°C, FeB will precipitate, resulting in significant deterioration of the magnetic properties.

[0045] According to the heat treatment method of the present disclosure, pressing the amorphous alloy ribbon against a heating body improves contact between the heating body and the ribbon, improving heat transfer and increasing the temperature rise rate. In addition, more of the heat generated by crystallization can be dissipated to the heating body and the pressing belt or roll, thereby suppressing the maximum temperature of the ribbon (suppressing temperature rise due to self-heating). Furthermore, pressing with a belt or roll can suppress wrinkles or streaks that tend to occur during crystallization. This enables heat treatment at higher temperatures, a faster temperature rise rate, and short-term contact. Therefore, productivity can be improved and a uniform nanocrystalline structure can be obtained, resulting in a nanocrystalline alloy ribbon with a higher saturation magnetic flux density and excellent magnetic properties.

[0046] [Heating Rate and Maximum Temperature of Amorphous Alloy Ribbon During Heat Treatment] The heating rate and maximum temperature of the amorphous alloy ribbon during heat treatment were confirmed using the following method. The surface temperature of the amorphous alloy ribbon was measured using a radiation thermometer FLHX-TNE0090 manufactured by Japan Sensor Co., Ltd. Because this radiation thermometer can only perform fixed-point measurements, the temperature of the amorphous alloy ribbon during heat treatment was measured without the ribbon being conveyed. As shown in FIG. 3 , the ribbon presser metal belt 33 was not driven, and the ribbon 1 was placed between the ribbon presser metal belt 33 and the heater 32. Tension was applied to the ribbon presser metal belt 33 to press the ribbon 1 against the heater 32. The ribbon was then pressed for a predetermined time, and the ribbon temperature was measured. This confirmed the temperature change after the ribbon was pressed against the heater. FIG. 8 shows an example of a measured temperature profile. The X-axis represents time (seconds), and the Y-axis represents the measured ribbon temperature. Using the above method, the ribbon was pressed against a heating body heated to a set temperature (520°C) and measured. The contact time in Figure 8 is the time during which the ribbon was pressed against the heating body. According to this measurement method, the ribbon temperature rises to about 400°C before contacting the heating body. Therefore, the temperature rise rate was calculated as the value obtained by dividing the temperature change from the time of contact with the heating plate until the set temperature (520°C) was reached by the time, as shown in Figure 8. The maximum ribbon temperature was the maximum peak temperature that appeared after the ribbon contacted the heating body. The ribbon temperature was measured by opening a measurement hole in the ribbon-pressing metal belt 33.

[0047] The pressure applied to press the amorphous alloy ribbon against the heater is preferably 0.03 MPa or more, more preferably 0.04 MPa or more, and even more preferably 0.05 MPa or more. It is also effective to provide a curvature to the heater to further improve contact between the amorphous alloy ribbon and the heater. The curvature of the heater preferably has a radius of curvature of 25 mm or more. To increase the temperature rise rate during heating of the amorphous alloy ribbon, it is also effective to heat the pressing belt or roll to the same temperature as the heater and heat the ribbon from both sides. In Figures 1, 2, and 3, heated rolls are used as rolls 4, 5, 6, 7, 8, 34, and 35. It is also effective to set the temperature of the belt or roll lower than the heating plate temperature Ta °C to suppress heat generation due to bccFe crystallization in the ribbon.

[0048] According to the present disclosure, it is possible to obtain a nanocrystalline alloy ribbon that has excellent magnetic properties and isotropy, and that is suppressed from having wrinkles or streaks and achieves a high space factor.

[0049] The nanocrystalline alloy ribbon of the present disclosure has a saturation magnetic flux density Bs of 1.75 T or more, and preferably 1.80 T or more. Furthermore, the nanocrystalline alloy ribbon of the present disclosure has a magnetic flux density B80 Ｌ and magnetic flux density B80 when a magnetic field of 80 A / m is applied in the width direction perpendicular to the longitudinal direction. Ｗ and the ratio (B80 Ｌ / B80 Ｗ ) is 0.80 to 1.20, and B80 Ｌ , B80 Ｗ Both are preferably 1.0T or more. (B80 Ｌ / B80 Ｗ ) is more preferably 0.90 to 1.10.

[0050] The nanocrystalline alloy ribbon of the present disclosure preferably has a space factor of 84.0% or more. The space factor is preferably 86% or more, and more preferably 88% or more. The space factor can be measured by the following method in accordance with JIS C 2534:2017. 20 ribbons cut to a length of 120 mm are stacked and set on a flat sample stage, and a flat anvil with a diameter of 16 mm is placed on the stacked ribbons at a pressure of 50 kPa, and the height is measured at 10 mm intervals in the width direction. The maximum height at this time is defined as hmax (μm), and the space factor LF is calculated using the following formula: LF (%) = sample weight (g) / density (g / cm ３ ) / hmax (μm) / sample length (240 cm) / ribbon width (cm) × 10000 At this time, density (g / cm ３ ) is the density of the alloy ribbon after the heat treatment. This density is 7.5 g / cm ３ It can be said that:

[0051] When an amorphous alloy ribbon is heated in contact with a heater to convert the amorphous alloy ribbon into a nanocrystalline alloy ribbon, local differences in the heating rate and temperature of the amorphous alloy ribbon due to variations in contact between the amorphous alloy ribbon and the heater can cause differences in the progress of crystallization. This can cause local distortion, resulting in the alloy ribbon floating up from the heater. In the floating area, it becomes difficult for the self-heating generated by crystallization to escape to the heater, causing the alloy ribbon temperature to rise sharply and reach the FeB precipitation temperature, making it prone to wrinkles or streaks. This reduces the space factor, and the wrinkled or streaked areas become very brittle, causing handling problems such as cracking during transportation and stacking, as well as deterioration of magnetic properties.

[0052] According to the present disclosure, a ribbon pressing member contacting the surface of the amorphous alloy ribbon opposite to the surface contacting the heating body presses the amorphous alloy ribbon against the heating body, thereby enabling uniform heating of the amorphous alloy ribbon and suppressing lifting of the alloy ribbon and the occurrence of wrinkles or streaks. Furthermore, this method also has the effect of correcting wrinkles and other defects caused by cooling variations during amorphous alloy ribbon casting. As a result, according to the present disclosure, wrinkles and streaks are suppressed, resulting in a nanocrystalline alloy ribbon with excellent flatness. The nanocrystalline alloy ribbon of the present disclosure preferably has a wrinkle or streak height of 0.15 mm or less, more preferably 0.10 mm or less. In the present disclosure, the wrinkle or streak height is also referred to as "wrinkle height." The wrinkle height can be evaluated using the method described in the following examples.

[0053] The nanocrystalline alloy ribbon of the present disclosure preferably has a coercive force Hc of 25 A / m or less, preferably 15 A / m or less, an iron loss (1 T, 1 kHz) of 15 W / kg or less, preferably 10 W / kg or less, and a saturation magnetostriction of 20 ppm or less, preferably 15 ppm.

[0054] The nanocrystalline alloy ribbon of the present disclosure preferably has a thickness of 20 μm or more, more preferably 25 μm or more, and even more preferably 30 μm or more. The width is preferably 10 mm or more, more preferably 100 mm or more, and even more preferably 200 mm or more. Note that, since it becomes difficult to obtain good magnetic properties when the nanocrystalline alloy ribbon of the present disclosure is thick, the thickness is preferably 50 μm or less, and more preferably 40 μm or less. Note that, since it becomes difficult to stably produce the nanocrystalline alloy ribbon of the present disclosure when the width is too wide, the width is preferably 500 mm or less, and more preferably 400 mm or less.

[0055] The nanocrystalline alloy ribbon of the present disclosure can be used to form magnetic cores for transformers, electronic components, motors, and the like, thereby obtaining magnetic cores with excellent properties. When forming a magnetic core, the magnetic core can be formed by cutting the alloy ribbon into a predetermined shape and stacking it, winding the alloy ribbon, stacking and bending the alloy ribbon, or the like. Furthermore, by combining the magnetic core of the present disclosure with a winding to form a component such as a transformer, electronic component, or motor, a component with excellent properties can be obtained. In this case, the magnetic core of the present disclosure may be combined with a magnetic core made of another magnetic material.

[0056] Example 1: Element sources were blended to obtain the compositions shown in Table 1 and heated to 1,300°C to produce molten alloys. The molten alloys were then ejected onto a chill roll with an outer diameter of 400 mm and a width of 200 mm, rotating at a peripheral speed of 30 m / s, and rapidly solidified on the chill roll to produce amorphous alloy ribbons. The outer periphery of the chill roll was made of a Cu alloy with a thermal conductivity of 150 W / (m·K), and an internal cooling mechanism was provided for controlling the temperature of the outer periphery. The produced amorphous alloy ribbons had a width of 50 mm and a thickness of 30 μm. The amorphous alloy ribbons of each material were measured using a Rigaku DSC8231 differential scanning calorimeter at a heating rate of 20 K / min to determine the crystallization onset temperature (Tx1°C) of bccFe (αFe) and the precipitation onset temperature (Tx2°C) of FeB. The results are shown in Table 1.

[0057] Nanocrystalline alloy ribbons were produced by heat treating amorphous alloy ribbons of the materials shown in Table 1 under different heat treatment conditions. The conditions and evaluation results are shown in Tables 2 and 3. Blanks in the tables indicate that no measurements were taken.

[0058] For each sample (nanocrystalline alloy ribbon), iron loss, saturation magnetic flux density Bs, magnetic flux density B80, coercive force Hc, saturation magnetostriction, particle size, volume fraction, wrinkle height, and space factor were measured.

[0059] [Iron Loss] The heat-treated single sheet sample was measured using an AC magnetic measuring device TWM18SR manufactured by Toei Kogyo under the conditions of a magnetic flux density of 1 T and a frequency of 1 kHz.

[0060] [Saturation Magnetic Flux Density Bs] A magnetic field of 8000 A / m is applied to the heat-treated single sheet sample using a DC magnetization characteristic tester manufactured by Metron Giken, and the maximum magnetic flux density at that time is measured and designated as Bs. The nanocrystalline alloy ribbon of the present disclosure has a property that is relatively prone to saturation, and therefore is saturated at the time when a magnetic field of 8000 A / m is applied, and B ８０００ Since the saturation magnetic flux density Bs is almost the same as B ８０００ It is expressed as:

[0061] [Magnetic Flux Density B80] Using a DC magnetization characteristic tester manufactured by Metron Giken, a magnetic field of 80 A / m was applied to the nanocrystalline alloy ribbon in the longitudinal direction (casting direction) and in the width direction perpendicular to the longitudinal direction, and the maximum magnetic flux density at that time was measured as B80. Ｌ , B80 Ｗ The ratio B80 Ｌ / B80 Ｗ was calculated and the isotropy was evaluated.

[0062] [Coercive force Hc] A magnetic field of 8000 A / m was applied to the nanocrystalline alloy ribbon in the longitudinal direction (casting direction) using a DC magnetization characteristic tester manufactured by Metron Giken, and then the magnetic field was gradually weakened until the magnetic flux density reached 0 T, which was taken as the coercive force.

[0063] [Saturation magnetostriction] A magnetic field of 5 kOe was applied to a sample with a strain gauge attached by Kyowa Electric Industrial Co., Ltd., using an electromagnet. The electromagnet was rotated 360°, and the direction of the magnetic field applied to the sample was changed by 360°. The maximum change in elongation and contraction of the sample was measured from the change in the electrical resistance of the strain gauge. Saturation magnetostriction was defined as 2 / 3 x maximum change.

[0064] [Particle size] The particle size refers to the average particle size of the nanocrystals. The average particle size of the nanocrystals was calculated using the full width at half maximum of the diffraction peak from the (110) plane in the X-ray diffraction pattern obtained from the X-ray diffraction experiment using the Scherrer equation. The full width at half maximum of the (110) peak was obtained by peak resolution using a pseudo-Voigt function for the diffraction pattern. If the average particle size is D, the full width at half maximum is W, the diffraction angle is θ, the Scherrer constant is K, and the wavelength of the X-ray is λ, then D can be calculated using the Scherrer equation (Equation 1) given below. In this case, however, the X-ray wavelength λ was assumed to be 0.154050 nm and the Scherrer constant K was assumed to be 0.891.

[0065]

[0066] [Volume Fraction] The volume fraction is the volume fraction of nanocrystals, and the portion other than the nanocrystals is the amorphous portion. This volume fraction is calculated as the ratio of the integrated intensity of the nanocrystals to the integrated intensity of (crystalline + amorphous). The integrated intensities of the peaks exhibited by nanocrystals and the halo patterns exhibited by amorphous are calculated by peak resolution using a pseudo-Voigt function for the X-ray diffraction pattern. If the total integrated intensity of all peaks exhibited by nanocrystals is Ic and the total integrated intensity of all halo patterns exhibited by amorphous is Ia, the volume fraction V can be calculated from the following formula (Equation 2).

[0067]

[0068] [Wrinkle Height] The wrinkle height refers to the height of wrinkles or streaks formed on the ribbon surface. Each sample (nanocrystalline alloy ribbon) was sandwiched between glass plates and the ribbon surface height was measured using a Keyence VR3200 laser microscope. The difference between the maximum and minimum values ​​was calculated as the wrinkle height. The ribbon was sandwiched between glass plates to minimize the influence of undulations and other factors on the ribbon height, which are very thin and affect the ribbon height when placed alone on the measurement stage. The laser microscope observation field was approximately 18 mm × 25 mm, and measurements were taken at three locations on each sample. The largest value was taken as the wrinkle height. A glass plate measuring 70 mm × 70 mm and 3 mm thick was used. Figure 4 shows the evaluation results of the amorphous alloy ribbon of Sample No. 4 before heat treatment. Due to the unevenness of the ribbon surface, the wrinkle height was 0.073 mm even before heat treatment. Figure 5 shows the measurement results for a nanocrystalline alloy ribbon (No. 8) obtained by heat-treating the amorphous alloy ribbon (Sample No. 4) at 510°C without pressing down. The wrinkles formed during heat treatment were clearly elevated, and the difference between the maximum and minimum values ​​(wrinkle height) was 0.156 mm. The space factor of No. 8 was 83.5%. Figure 6 shows the measurement results for a nanocrystalline alloy ribbon (No. 9) obtained by heat-treating the amorphous alloy ribbon (Sample No. 4) at 515°C without pressing down. Wrinkles formed over almost the entire surface, and the difference between the maximum and minimum values ​​(wrinkle height) was 0.381 mm. The space factor of No. 9 was 78.0%. Figure 7 shows the measurement results for the nanocrystalline alloy ribbon (Sample No. 4) heat-treated at a pressing pressure of 0.115 MPa and a heater temperature of 530°C. There were no wrinkles, and the wrinkle height was 0.052 mm, which was better than that of amorphous alloy ribbons. By pressing the ribbon during heat treatment, wrinkles or streaks can be suppressed, allowing for heat treatment at a higher temperature than when the ribbon is not pressed. The space factor was also good, at 89.3%. Furthermore, in Example No. 1, a wrinkle height of 0.072 mm was obtained, resulting in a space factor of 89.0%. In Example No. 5, a wrinkle height of 0.043 mm was obtained, resulting in a space factor of 89.2%. In Example No. 6, a wrinkle height of 0.087 mm was obtained, resulting in a space factor of 89.0%. Furthermore, in Example No. 7, a wrinkle height of 0.220 mm was obtained, which was high.In No. 7, the pressure applied by the thin ribbon pressing member was low at 0.029 MPa, which is thought to be the reason for the high wrinkle height.

[0069]

[0070]

[0071]

[0072] According to an embodiment of the present disclosure, Bs is 1.75T or more, and B80 Ｌ , B80 Ｗ are all 1.0T or more, and the ratio B80 Ｌ / B80 Ｗ The obtained samples had a coercive force Hc in the range of 0.80 to 1.20. Furthermore, the coercive force Hc and iron loss were low, and the samples exhibited excellent magnetic properties. Therefore, a nanocrystalline alloy ribbon was obtained that not only had excellent magnetic properties but also had isotropy. Furthermore, the wrinkle height was low, and wrinkles or streaks were suppressed, and a nanocrystalline alloy ribbon was obtained that achieved a high space factor. Furthermore, the average grain size of the nanocrystals was 30 nm or less, and the volume fraction of the nanocrystals was 30% or more. Samples Nos. 14, 15, and 16 were heat-treated without pressing the ribbon against a heater, and B80 Ｌ / B80 Ｗ The results showed that the coercive force Hc was high, with the value of B80 not falling within the range of 0.80 to 1.20. Samples No. 8 and No. 9 were heat treated without pressing the ribbon against a heating body, resulting in large wrinkle heights and a low space factor. Sample No. 19 had a ribbon maximum temperature exceeding Tx2 + 160°C, resulting in high (poor) coercive force Hc and iron loss, low B80, and Ｌ / B80 Ｗ was greater than 1.2.

Claims

1. A method for producing a nanocrystalline alloy ribbon having a structure in which crystal grains having an average grain size of 30 nm or less are present in an amorphous phase by contacting an amorphous alloy ribbon with a heater and heating the amorphous alloy ribbon, comprising the steps of: The nanocrystalline alloy ribbon is represented by a composition formula (Fe1-xAx)aSibBcCudMe, A is at least one of Ni and Co, M is at least one selected from Nb, Mo, V, Zr, Hf and W, and the atomic percentages are 80.0≦a≦87.0, 0≦b≦9.0, 12.0≦c≦16.0, 0≦d≦1.5, 0≦e≦1.5, and 0≦x≦0.1; When the amorphous alloy ribbon is heated by contacting the heating body with the amorphous alloy ribbon, the amorphous alloy ribbon is transported and a ribbon pressing member is brought into contact with a surface of the amorphous alloy ribbon opposite to a surface of the amorphous alloy ribbon that is in contact with the heating body, and the amorphous alloy ribbon is heated in a state of being sandwiched between the heating body and the ribbon pressing member, When the bccFe crystallization starting temperature measured at a heating rate of 20 K / min of the amorphous alloy ribbon is defined as Tx1°C, the heating body is heated to a heating temperature Ta of Tx1+80°C or more and Tx1+160°C or less.

2. The method for producing a nanocrystalline alloy ribbon according to claim 1, wherein the ribbon pressing member is a flexible member.

3. The method for producing a nanocrystalline alloy ribbon according to claim 1 or 2, wherein when the amorphous alloy ribbon is brought into contact with the heating body and heated, the temperature rise rate of the amorphous alloy ribbon is 50°C / sec to 4000°C / sec.

4. 3. The method for producing a nanocrystalline alloy ribbon according to claim 1 or 2, wherein when the amorphous alloy ribbon is brought into contact with the heating body to heat the amorphous alloy ribbon, the conveying speed of the amorphous alloy ribbon is 1 m / min or more.

5. The method for producing a nanocrystalline alloy ribbon according to claim 1 or 2, wherein when the amorphous alloy ribbon is heated by contacting the amorphous alloy ribbon with the heating body, the contact time of the amorphous alloy ribbon with the heating body is 0.1 seconds to 30 seconds.

6. 3. The method for producing a nanocrystalline alloy ribbon according to claim 1 or 2, wherein the FeB precipitation start temperature measured at a heating rate of 20 K / min of the amorphous alloy ribbon is Tx2°C, and the maximum temperature of the amorphous alloy ribbon heated in contact with the heating body is controlled to be Tx2+160°C or less.

7. 3. The method for producing a nanocrystalline alloy ribbon according to claim 1 or 2, wherein, in the composition formula, 82.0≦a≦86.5, 0.01≦b≦3.0, 13.0≦c≦15.0, 0.01≦d≦1.5, and 0≦e≦1.

5.

8. 3. The method for producing a nanocrystalline alloy ribbon according to claim 1, wherein the amorphous alloy ribbon is heated while being pressed by the heating body or the ribbon pressing member, and the pressure at which the amorphous alloy ribbon is pressed is 0.03 MPa or more.

9. 3. The method for producing a nanocrystalline alloy ribbon according to claim 1, wherein the wrinkle height on the surface of the nanocrystalline alloy ribbon is 0.15 mm or less, and the space factor is 84.0% or more.

10. 3. The method for producing a nanocrystalline alloy ribbon according to claim 1, wherein the nanocrystalline alloy ribbon has a saturation magnetic flux density Bs of 1.75 T or more.

11. The method for producing a nanocrystalline alloy ribbon according to claim 1 or 2, wherein a ratio (B80L / B80W) of a magnetic flux density B80L when a magnetic field of 80 A / m is applied in the longitudinal direction of the nanocrystalline alloy ribbon to a magnetic flux density B80W when a magnetic field of 80 A / m is applied in a width direction perpendicular to the longitudinal direction is 0.80 to 1.20, and both B80L and B80W are 1.0 T or more.

12. 3. The method for producing a nanocrystalline alloy ribbon according to claim 1, wherein the nanocrystalline alloy ribbon has a coercive force Hc of 25 A / m or less, an iron loss (1 T, 1 kHz) of 15 W / kg or less, and a saturation magnetostriction of 20 ppm or less.

13. 3. The method for producing a nanocrystalline alloy ribbon according to claim 1, wherein the amorphous alloy ribbon has a thickness of 20 μm or more and a width of 10 mm or more.

14. A nanocrystalline alloy ribbon having a structure in which crystal grains having an average grain size of 30 nm or less exist in an amorphous phase, The composition is represented by the formula (Fe1-xAx)aSibBcCudMe, A is at least one of Ni and Co, M is at least one selected from Nb, Mo, V, Zr, Hf and W, and the atomic percentages are 80.0≦a≦87.0, 0≦b≦9.0, 12.0≦c≦16.0, 0≦d≦1.5, 0≦e≦1.5, and 0≦x≦0.

1. The saturation magnetic flux density Bs is 1.75 T or more, A nanocrystalline alloy ribbon, in which the ratio (B80L / B80W) of a magnetic flux density B80L when a magnetic field of 80 A / m is applied in the longitudinal direction of the nanocrystalline alloy ribbon to a magnetic flux density B80W when a magnetic field of 80 A / m is applied in a width direction perpendicular to the longitudinal direction is 0.80 to 1.20, and both B80L and B80W are 1.0 T or more.

15. The nanocrystalline alloy ribbon according to claim 14, wherein, in the composition formula, 82.0≦a≦86.5, 0.01≦b≦3.0, 13.0≦c≦15.0, 0.01≦d≦1.5, and 0≦e≦1.

5.

16. The nanocrystalline alloy ribbon according to claim 14 or 15, wherein the wrinkle height on the surface of the nanocrystalline alloy ribbon is 0.15 mm or less, and the space factor is 84.0% or more.

17. The nanocrystalline alloy ribbon according to claim 14 or 15, having a coercive force Hc of 25 A / m or less, an iron loss (1 T, 1 kHz) of 15 W / kg or less, and a saturation magnetostriction of 20 ppm or less.

18. The nanocrystalline alloy ribbon according to claim 14 or 15, which has a thickness of 20 µm or more and a width of 10 mm or more.