EP4790165A1

EP4790165A1 - Fe-based amorphous alloy and thin fe-based amorphous alloy strip

Info

Publication number: EP4790165A1
Application number: EP24874351.0A
Authority: EP
Inventors: Shinya Sato; Shigekatsu Ozaki; Yuichi Sato
Original assignee: Nippon Steel Corp
Current assignee: Nippon Steel Corp
Priority date: 2023-10-04
Filing date: 2024-08-09
Publication date: 2026-08-12
Also published as: JPWO2025074737A1; CN121941793A; MX2026003599A; TW202516031A; KR20260041141A; AU2024354536A1; WO2025074737A1

Abstract

An Fe-based amorphous alloy according to an aspect of the present disclosure contains, in atom%, B: 8.0% or more and 18.0% or less, Si: 0% or more and 2.0% or less, C: 0.10% or more and 5.00% or less, P: 0.10% or more and 3.50% or less, Mn: 0% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, and a remainder including impurities, in which a microstructure of the Fe-based amorphous alloy is amorphous.

Description

TECHNICAL FIELD

The present disclosure relates to an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon, and particularly relates to an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon excellent in soft magnetic properties.
The present application claims priority based on Japanese Patent Application No. 2023-172448 filed in Japan on October 4, 2023 , the contents of which are incorporated herein by reference.

BACKGROUND ART

As methods for continuously manufacturing ribbons or wires by rapidly cooling an alloy in a molten state, a centrifugal rapid cooling method, a single roll method, a twin roll method, and the like have been known. These methods involve rapidly solidifying a molten metal by ejecting the molten metal from an orifice or the like onto either an inner circumferential surface or an outer circumferential surface of a metal drum rotating at a high speed, thereby manufacturing ribbons or wires. Furthermore, it is possible to obtain an amorphous alloy similar to a liquid metal through the appropriate selection of an alloy composition, thereby enabling the manufacturing of a material with excellent magnetic properties.
In particular, among amorphous alloys, Fe-based amorphous alloys are promising as applications such as cores for power transformers, high-frequency transformers. In order to improve the performance of these applications, there is a strong demand for further reducing the iron loss and further improving the saturation magnetic flux density of the Fe-based amorphous alloy. However, it was extremely difficult to obtain an Fe-based amorphous alloy having an iron loss W_13/50 of 0.105 W/kg or less at a magnetic flux density of 1.3 T and a frequency of 50 Hz and a saturation magnetic flux density of 1.60 T or higher.
It is described in Patent Document 1 that an amorphous alloy ribbon having an alloy composition represented by Fe_aSi_bB_cC_d, and containing, in atom%, 76 ≤ a < 84%, 0 < b ≤ 12%, 8 ≤ c ≤ 18%, 0.01 ≤ d ≤ 3% and unavoidable impurities, in which a peak value of the concentration distribution of C is present within a depth range of 2 to 20 nm upon measurement of the concentration distribution of C from the surfaces to the interior for both the free surface and the roll surface.
It is described in Patent Document 2 that an amorphous alloy ribbon having an alloy composition represented by Fe_aSi_bB_cC_dCr_eMn_f, and containing, in atom%, 79 ≤ a ≤ 83%, 0 < b ≤ 10%, 10 ≤ c ≤ 18%, 0.05 ≤ d ≤ 2%, 0.01 ≤ e ≤ 0.2%, 0.05 ≤ f ≤ 0.3%, and unavoidable impurities, in which assuming that a peak concentration of carbon C segregated at a position of 2 to 25 nm from a surface of a ribbon is p₁ (atom%) and the amount of carbon is d, p₁/d is 1.5 or less.
It is described in Patent Document 3 that an Fe-based amorphous alloy ribbon contains, in atom%, B: 5% to 25%, Si: 1% to 30%, and N: 0.001% to 0.2%, with a remainder composed of Fe and unavoidable impurities.
In Patent Document 1, controlling Si and C contents, roll surface roughness, and the amount of gas blown onto the roll enables control over the position and peak value of C-segregation layers on both the free surface and roll surface, resulting in an increase in the B₈₀/BS ratio, an improvement in thermal stability, and minimization of embrittlement. However, no study has been conducted to reduce an iron loss W_13/50 to 0.105 W/kg or less while achieving a saturation magnetic flux density of 1.60 T or higher.
In Patent Document 2, although improvements in long-term thermal stability have been achieved by using materials with Cr and Mn added to control the peak concentration of C-segregation layers, and by applying predetermined heat treatment to the amorphous alloy ribbon in advance, no study has been conducted to reduce an iron loss W_13/50 to 0.105 W/kg or less while achieving a saturation magnetic flux density of 1.60 T or higher.
In Patent Document 3, the inclusion of N in Fe-B-Si-based and Fe-B-Si-C-based amorphous alloys causes impurity elements (such as Al), which are known as elements promoting crystallization, to concentrate in the surface oxide layer, thereby minimizing crack propagation in the amorphous alloy ribbon and improving formability. However, no study has been conducted to reduce an iron loss W_13/50 to 0.105 W/kg or less while achieving a saturation magnetic flux density of 1.60 T or higher.

Citation List

Patent Documents

Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2006-45662
Patent Document 2: Japanese Unexamined Patent Application, First Publication No. 2009-52064
Patent Document 3: Japanese Unexamined Patent Application, First Publication No. 2006-316348

SUMMARY OF INVENTION

Technical Problem

The present disclosure has been made in view of the above circumstances, and an object thereof is to provide an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon having a low iron loss and a high magnetic flux density.

Solution to Problem

The gist of the present disclosure is as follows.

(1) An Fe-based amorphous alloy according to an aspect of the present disclosure contains, in atom%, B: 8.0% or more and 18.0% or less, Si: 0% or more and 2.0% or less, C: 0.10% or more and 5.00% or less, P: 0.10% or more and 3.50% or less, Mn: 0% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, and a remainder including impurities, in which a microstructure of the Fe-based amorphous alloy is amorphous.
(2) The Fe-based amorphous alloy according to (1) described above preferably contains, in atom%, Mn: 0.05% or more and 0.60% or less.
(3) The Fe-based amorphous alloy according to (1) described above preferably contains, in atom%: C: 1.00% or more and 5.00% or less; and Mn: 0.05% or more and 0.60% or less.
(4) The Fe-based amorphous alloy according to (1) described above preferably contains, in atom%: C: 2.00% or more and 5.00% or less; and Mn: 0.05% or more and 0.60% or less.
(5) The Fe-based amorphous alloy according to (1) described above preferably contains, in atom%: P: 0.50% or more and 3.50% or less; and Mn: 0.05% or more and 0.60% or less.
(6) The Fe-based amorphous alloy according to (1) described above preferably contains, in atom%: C: 1.00% or more and 5.00% or less; P: 0.50% or more and 3.50% or less; and Mn: 0.05% or more and 0.60% or less.
(7) The Fe-based amorphous alloy according to (1) described above preferably contains, in atom%: C: 2.00% or more and 5.00% or less; P: 0.50% or more and 3.50% or less; and Mn: 0.05% or more and 0.60% or less.
(8) In the Fe-based amorphous alloy according to any one of (1) to (7) described above, Fe is preferably substituted with at least one or more elements of Ni, Cr, and Co in a range of 10.0 atom% or less.
(9) In the Fe-based amorphous alloy according to any one of (1) to (7) described above, an iron loss W_13/50 upon magnetization at a frequency of 50 Hz and a magnetic flux density of 1.3 T is preferably 0.105 W/kg or less, and a saturation magnetic flux density is preferably 1.60 T or higher.
(10) In the Fe-based amorphous alloy according to (8) described above, an iron loss W_13/50 upon magnetization at a frequency of 50 Hz and a magnetic flux density of 1.3 T is preferably 0.105 W/kg or less, and a saturation magnetic flux density is preferably 1.60 T or higher.
(11) In the Fe-based amorphous alloy according to (10) described above, the iron loss W_13/50 is preferably 0.097 W/kg or less.
(12) An Fe-based amorphous alloy ribbon according to another aspect of the present disclosure contains the Fe-based amorphous alloy according to any one of (1) to (7) described above.
(13) An Fe-based amorphous alloy ribbon according to another aspect of the present disclosure contains the Fe-based amorphous alloy according to (8) described above.
(14) An Fe-based amorphous alloy ribbon according to another aspect of the present disclosure contains the Fe-based amorphous alloy according to (9) described above.
(15) An Fe-based amorphous alloy ribbon according to another aspect of the present disclosure contains the Fe-based amorphous alloy according to (10) described above.
(16) An Fe-based amorphous alloy ribbon according to another aspect of the present disclosure contains the Fe-based amorphous alloy according to (11) described above. Advantageous Effects of Invention

According to the present disclosure, it is possible to provide the Fe-based amorphous alloy and the Fe-based amorphous alloy ribbon having a low iron loss and a high magnetic flux density.

DESCRIPTION OF EMBODIMENTS

The present inventors have found that adjusting the amount of amorphous-forming elements such as B, C, Si, and P improves the amorphous-forming ability and enables the manufacturing of Fe-based amorphous alloys with excellent soft magnetic properties. Specifically, it has been found that an iron loss W_13/50 of 0.105 W/kg or less and a saturation magnetic flux density of 1.60 T or higher can be achieved. Furthermore, it has been found that the inclusion of Mn in a range of 0.05% or more and 0.60% or less enables further improvement in the soft magnetic properties.
Hereinafter, an Fe-based amorphous alloy and an Fe-based amorphous alloy ribbon, which are embodiments of the present disclosure, will be described.
In the present embodiment, the phrase "excellent soft magnetic properties" refers to characteristics that include low iron loss and high saturation magnetic flux density.
The Fe-based amorphous alloy of the present embodiment contains, in atom%, B: 8.0% or more and 18.0% or less, Si: 0% or more and 2.0% or less, C: 0.10% or more and 5.00% or less, P: 0.10% or more and 3.50% or less, Mn: 0% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, and a remainder including impurities, wherein a microstructure of the Fe-based amorphous alloy is amorphous.
Furthermore, the Fe-based amorphous alloy of the present embodiment contains, in atom%, B: 8.0% or more and 18.0% or less, Si: 0% or more and 2.0% or less, C: 0.10% or more and 5.00% or less, P: 0.10% or more and 3.50% or less, Mn: 0.05% or more and 0.60% or less, Fe: 78.00% or more and 86.00% or less, and a remainder including impurities, wherein a microstructure of the Fe-based amorphous alloy is amorphous.
Furthermore, in the Fe-based amorphous alloy of the present embodiment, the C content may be 1.00% or more and 5.00% or less.
Furthermore, in the Fe-based amorphous alloy of the present embodiment, the C content may be 2.00% or more and 5.00% or less.
Furthermore, in the Fe-based amorphous alloy of the present embodiment, the P content may be 0.50% or more and 3.50% or less.
Furthermore, in the Fe-based amorphous alloy of the present embodiment, the C content may be 1.00% or more and 5.00% or less, and the P content may be 0.50% or more and 3.50% or less.
Furthermore, in the Fe-based amorphous alloy of the present embodiment, the C content may be 2.00% or more and 5.00% or less, and the P content may be 0.50% or more and 3.50% or less.
Furthermore, in the Fe-based amorphous alloy of the present embodiment, Fe may be substituted with at least one or more elements of Ni, Cr, and Co in a range of 10.0 atom% or less.
Furthermore, the Fe-based amorphous alloy ribbon of the present embodiment is composed of the above-described Fe-based amorphous alloy.
First, the reason why the amount of each element is limited in the Fe-based amorphous alloy of the present embodiment will be described.
B is contained in the Fe-based amorphous alloy of the present embodiment in order to improve the amorphous phase formation and the thermal stability of the amorphous phase. On the premise that the other elements are present within the above-described compositional range, optimization of the amount of this element can be performed to stably form an amorphous phase in the alloy microstructure, thereby enabling a further improvement in the soft magnetic properties. For example, the saturation magnetic flux density can be stably set to 1.60 T or higher. In a case where B is less than 8.0 atom%, an improvement in amorphous phase-forming ability cannot be achieved, and the amorphous alloy cannot be stably obtained in the Fe-based amorphous alloy, resulting in difficulty in stably achieving a saturation magnetic flux density of 1.60 T or higher while stably maintaining an iron loss of 0.105 W/kg or less. In contrast, in a case where B is more than 18.0 atom%, the improvement in amorphous phase-forming ability also cannot be achieved, and it is difficult to stably achieve a saturation magnetic flux density to 1.60 T or higher. Therefore, B is set to 8.0 atom% or more and 18.0 atom% or less. The lower limit of B is preferably 10.0 atom%, and still more preferably 13.0 atom%. The upper limit of B is preferably 16.0 atom%, and still more preferably 15.0 atom%.
Similar to B, Si is contained in the Fe-based amorphous alloy of the present embodiment in order to improve the amorphous phase formation and the thermal stability of the amorphous phase. However, Si is not a necessary element, and the amount of Si may be 0 atom%. On the premise that the other elements are present within the above-described compositional range, optimization of the amount of Si can be performed to stably form an amorphous phase in the alloy microstructure, thereby enabling a further improvement in the soft magnetic properties. In a case where Si is more than 2.0 atom%, the improvement in amorphous phase-forming ability also cannot be achieved, and it is difficult to stably achieve an iron loss of 0.105 W/kg or less. Therefore, Si is set to 0 atom% or more and 2.0 atom% or less. The lower limit of Si is preferably more than 0 atom%, and still more preferably 0.1 atom%, 0.2 atom%, 0.3 atom%, or 0.5 atom%. The upper limit of Si is preferably 1.9 atom%, 1.8 atom%, 1.5 atom%, or 1.3 atom%, and still more preferably 1.0 atom%.
Similar to B and Si, C is contained in the Fe-based amorphous alloy of the present embodiment in order to improve the amorphous phase formation and the thermal stability of the amorphous phase. On the premise that the other elements are present within the above-described compositional range, optimization of the amount of C can be performed to stably form an amorphous phase in the alloy microstructure, thereby enabling a further improvement in the soft magnetic properties. In a case where C is less than 0.10 atom%, an improvement in amorphous phase-forming ability cannot be achieved, and the amorphous alloy cannot be stably obtained in the Fe-based amorphous alloy, resulting in difficulty in stably achieving a saturation magnetic flux density of 1.60 T or higher while stably maintaining an iron loss of 0.105 W/kg or less. In contrast, in a case where C is more than 5.00 atom%, the improvement in amorphous phase-forming ability also cannot be achieved, and it is difficult to stably achieve an iron loss of 0.105 W/kg or less. Therefore, C is set to 0.10 atom% or more and 5.00 atom% or less. The lower limit of C is preferably 1.00 atom%, more preferably more than 1.90 atom%, and still more preferably 2.00 atom%. The upper limit of C is preferably 4.50 atom%, and still more preferably 4.00 atom%.
Similar to B, Si, and C, P is contained in order to improve the amorphous phase formation and the thermal stability of the amorphous phase. On the premise that the other elements are present within the above-described compositional range, optimization of the amount of P can be performed to stably form an amorphous phase in the alloy microstructure, thereby enabling a further improvement in the soft magnetic properties. In a case where P is less than 0.10 atom%, an improvement in amorphous phase-forming ability cannot be achieved, and the amorphous alloy cannot be stably obtained in the Fe-based amorphous alloy, resulting in difficulty in stably maintaining an iron loss of 0.105 W/kg or less. In contrast, in a case where P is more than 3.50 atom%, the improvement in amorphous phase-forming ability also cannot be achieved, and it is difficult to stably achieve an iron loss of 0.105 W/kg or less. Therefore, P is set to 0.10 atom% or more and 3.50 atom% or less. The lower limit of P is preferably 0.20 atom%, and still more preferably 0.50 atom%. The upper limit of P is preferably 3.00 atom%, and still more preferably 2.50 atom%.
Furthermore, in the present embodiment, the total amount of Si and C, which are elements having the amorphous-forming ability, may be more than 3.70 atom%, or may be 4.00 atom% or more.
Furthermore, in the present embodiment, the total amount of C and P, which are elements having the amorphous-forming ability, may be more than 4.90 atom%, or may be 5.00 atom% or more.
Furthermore, in the present embodiment, the total amount of Si, C, and P, which are elements having the amorphous-forming ability, may be more than 5.90 atom%, or may be 6.00 atom% or more.
Mn is an optional additive element and is not a necessary element. Therefore, the amount of Mn may be set to 0 atom%. On the other hand, Mn can be contained in the Fe-based amorphous alloy of the present embodiment in order to further improve the soft magnetic properties. On the premise that the other elements are present within the above-described compositional range, optimization of the amount of Mn can be performed to stably achieve a saturation magnetic flux density of 1.60 T or higher while stably maintaining an iron loss of 0.105 W/kg or less, for example. In a case where Mn is 0.02 atom% or more, or 0.05 atom% or more, it is possible to stably achieve a saturation magnetic flux density of 1.60 T or higher while stably maintaining an iron loss of 0.105 W/kg or less. On the other hand, in a case where Mn is more than 0.60 atom%, it is difficult to stably achieve an iron loss of 0.105 W/kg or less. Therefore, Mn is preferably set to, for example, 0.05 atom% or more and 0.60 atom% or less. The lower limit of Mn is preferably 0.10 atom%, and still more preferably 0.20 atom%. The upper limit of Mn is preferably 0.50 atom%, and still more preferably 0.40 atom%. For example, by setting the lower limit of Mn to 0.10 atom%, the iron loss W_13/50 can be 0.097 W/kg.
In the Fe-based amorphous alloy, in a case where the amount of Fe is usually 70 atom% or more, a practically applicable level of saturation magnetic flux density for a general magnetic core can be obtained, but in order to obtain a high saturation magnetic flux density of 1.60 T or higher, it is necessary to set Fe to 78.00 atom% or more on the premise that other elements are present within the above-described compositional range. In contrast, in a case where the amount of Fe is more than 86.00 atom%, it is difficult to form an amorphous phase, and it is difficult to obtain good soft magnetic properties (iron loss W_13/50 is stably 0.105 W/kg or less) characteristic of an amorphous alloy. Therefore, in the Fe-based amorphous alloy of the present embodiment, the amount of Fe is set to 78.00 atom% or more and 86.00 atom% or less. The lower limit of Fe is preferably 79.00 atom%, and still more preferably 80.00 atom%. The upper limit of Fe is preferably 85.00 atom%, and more preferably 84.00 atom%.
In the Fe-based amorphous alloy of the present embodiment, Fe may be substituted in part with at least one of Ni, Cr, and Co in a range of 10.0 atom% or less. In other words, in the Fe-based amorphous alloy of the present embodiment, the total of the amount of Fe and the contents of Ni, Cr, and Co may be 78.00 atom% or more and 86.00 atom% or less, and The total amounts of Ni, Cr, and Co may be 0 atom% or more and 10.0 atom% or less.
Substitution of Fe in part with at least one of Ni, Cr, and Co enables the achievement of improvements in soft magnetic properties such as the iron loss, while maintaining a high saturation magnetic flux density. The reason why the upper limit is set for the substitution amount of these elements is that, in a case where the content is more than 10.0 atom%, the saturation magnetic flux density is lowered or the raw material cost is increased.
In a case where Fe is substituted with one or more of Ni, Cr, and Co, The total amounts of Ni, Cr, and Co and the amount of Fe may be 78.00 atom% or more and 86.00 atom% or less, 79.00 atom% or more and 85.00 atom% or less, or 80.00 atom% or more and 84.00 atom% or less.
The total amounts of Ni, Cr, and Co may be 0 atom%, but may be 0.1 atom% or more, 0.5 atom% or more, 1.0 atom% or more, or 3.0 atom% or more. The total amounts of Ni, Cr, and Co may be 9.0 atom% or less, 8.0 atom% or less, 5.0 atom% or less, or 2.0 atom% or less.
The remainder in the Fe-based amorphous alloy according to the present embodiment is impurities. For example, in a case where a steel material is used as an Fe source, the Fe-based amorphous alloy according to the present embodiment may contain impurity elements contained in the steel material as impurities in a total of less than 0.100 atom%. For example, O, N, S, Al, Ti, Cu, V, As, Sn, Nb, Mo, Zr, Ca, Mn, Sb, Bi, Mg, As, Se, Te, Pb, REM, Zn, W, Ba, Cd, Pt, Au, In, Ga, Ge, Sc, Hf, and the like may be contained as impurities in a total of less than 0.100 atom%.
The chemical composition may be measured by a general analysis method. For example, the chemical composition may be measured using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Specifically, the chemical composition is specified by measuring a test piece collected from the Fe-based amorphous alloy with a predetermined measuring device under a condition based on a calibration curve prepared in advance. C and S may be measured using a combustion-infrared absorption method, and N may be measured using an inert gas fusion-thermal conductivity method. O may be measured by inert gas fusion-non-dispersive infrared absorption method.
The Fe-based amorphous alloy of the present embodiment has an amorphous microstructure. As a result, excellent soft magnetic properties can be obtained. Whether or not the Fe-based amorphous alloy has an amorphous microstructure can be confirmed by, for example, X-ray diffraction measurement with an X-ray diffractometer using a Cu target. That is, in a case where a clear diffraction peak cannot be obtained in the X-ray diffraction measurement, it can be confirmed that the Fe-based amorphous alloy has an amorphous microstructure. Here, the phrase "a clear diffraction peak cannot be obtained in the X-ray diffraction measurement" means that there is no α-Fe(110) diffraction peak having a half width of 4deg or less.
The Fe-based amorphous alloy and Fe-based amorphous alloy ribbon of the present embodiment exhibit excellent soft magnetic properties, with a saturation magnetic flux density of 1.60 T or more and more preferably 1.61 T or more, and with an iron loss (W_13/50) of 0.105 W/kg or less at a magnetic flux density of 1.3 T and a frequency of 50 Hz, which are obtained in a case where the saturation magnetic flux density and iron loss are measured by the method described below. The iron loss W_13/50 is preferably 0.100 W/kg or less, 0.097 W/kg or less, or 0.095 W/kg or less.
The iron loss is measured using a single strip tester (SST). The iron loss measurement conditions are a magnetic flux density of 1.3 T and a frequency of 50 Hz. Samples for iron loss measurement are collected from six locations over the entire length of a ribbon from a single lot. Each sample for iron loss measurement is a ribbon sample cut into a length of 120 mm. These ribbon samples for iron loss measurement are annealed in a magnetic field (magnetic field: 800 A/m, magnetic field applied in casting direction) at a predetermined temperature selected from a range of 320°C to 380°C for 1 hour and subjected to measurement. The atmosphere during annealing is a nitrogen atmosphere. On the other hand, the saturation magnetic flux density is measured using a vibrating sample magnetometer (VSM). A BH full loop is measured at a maximum magnetizing force of 10 kOe, and an average value of the maximum magnetic polarization values on the positive side and the negative side is defined as a saturation magnetic flux density. The samples for the VSM are thin pieces collected from the center portion of the width of each of the ribbon samples from the six locations.
Hereinafter, the Fe-based amorphous alloy and a method for manufacturing the Fe-based amorphous alloy ribbon of the present embodiment will be described. The Fe-based amorphous alloy of the present embodiment can be usually obtained in the form of a ribbon. This Fe-based amorphous alloy ribbon can be manufactured by a method of melting an alloy composed of the components described in the above embodiment, ejecting a molten metal through a slot nozzle or the like onto a cooling sheet moving at a high speed, and rapidly cooling and solidifying the molten metal, such as a single-roll method or a twin-roll method. The roll used in these roll methods is made of metal, and rapid cooling and solidification of the alloy can be performed by rotating the roll at a high speed and causing the molten metal to collide with a roll surface or a roll inner surface.
The single roll device also includes a centrifugal rapid cooling device using the inner wall of a drum, a device using an endless-type belt, an auxiliary roll which is an improved type thereof, a device to which a roll surface temperature control device is attached, and a casting device under reduced pressure or in vacuum or in an inert gas.
In the present embodiment, the dimensions such as the sheet thickness and the sheet width of the ribbon are not particularly limited, and the sheet thickness of the ribbon is preferably, for example, 10 µm or more and 100 µm or less. The sheet width is preferably 10 mm or more.
The Fe-based amorphous alloy ribbon obtained as described above can be used for applications such as a core in a power transformer and a high-frequency transformer.
Furthermore, the Fe-based amorphous alloy of the present embodiment can be in the form of powder in addition to the ribbon. In order to obtain a powdery Fe-based amorphous alloy, it is possible to adopt a method of ejecting a molten alloy or droplets of a molten alloy at a high speed onto a rotating roll or into a liquid such as cooling water from a nozzle of a crucible filled with the molten alloy having the above-described composition, and rapid cooling and solidifying the droplets.
An Fe-based amorphous alloy powder having excellent soft magnetic properties can be obtained by the above-described method.
The Fe-based soft magnetic alloy powder obtained as described above can be applied to applications such as a power transformer, a high-frequency transformer, and a core of a coil by compacting the Fe-based soft magnetic alloy powder with a die or the like, molding the Fe-based soft magnetic alloy powder into a desired shape, and sintering and integrating the Fe-based soft magnetic alloy powder as necessary.
As described above, according to the Fe-based amorphous alloy and the Fe-based amorphous alloy ribbon of the present embodiment, by optimizing the contents of B, Si, C, and P, along with increasing the Fe content to 78.00% or more, it is possible to achieve an iron loss (iron loss W_13/50) of 0.105 W/kg or less at a magnetic flux density of 1.3 T and a frequency of 50 Hz, and a saturation magnetic flux density of 1.60 T or higher, thereby exhibiting excellent soft magnetic properties, and it is possible to achieve suitable use for components of a passive element utilizing electromagnetic induction in coils. Furthermore, the Fe-based amorphous alloy and the Fe-based amorphous alloy ribbon of the present embodiment can also be suitably used as a motor component. Specifically, it can be suitably used for a transformer magnetic core, an inductor magnetic core, a choke magnetic core, a reactor magnetic core, and the like. Furthermore, it can be suitably used as a stator core or a rotor core of a motor. Therefore, the Fe-based amorphous alloy of the present embodiment is preferably an Fe-based amorphous alloy for a passive element using electromagnetic induction of a coil or an Fe-based amorphous alloy for a motor. Similarly, the Fe-based amorphous alloy ribbon of the present embodiment is preferably an Fe-based amorphous alloy ribbon for a passive element using electromagnetic induction of a coil or an Fe-based amorphous alloy ribbon for a motor. Moreover, it is preferable to use an Fe-based amorphous alloy or an Fe-based amorphous alloy ribbon for a magnetic core of a transformer, inductor, choke, reactor, or motor.

Examples

Hereinafter, examples of the present disclosure are described.

(Example 1)

Alloys of various components illustrated in Table 1A, Table 1B, and Table 1C were melted in an argon atmosphere, rapidly cooled by a single roll device, and cast to prepare ribbons of an Fe-based amorphous alloy. Note that the numerical values in the "Fe (atom%)" column in Table 1A, Table 1B, and Table 1C also include the amount of impurities. The casting atmosphere was in the atmosphere. Note that the single roll device used includes a cooling roll made of a copper alloy having a diameter of 300 mm, a high-frequency power source for dissolving a sample, a quartz crucible having a slot nozzle at the tip, and the like. In the present experiment, a slot nozzle having a length of 10 mm and a width of 0.6 mm was used. The peripheral speed of the cooling roll was set to 24 m/sec. As a result, the sheet thickness of the obtained ribbon was about 20 µm, the sheet width was 10 mm since the sheet width depends on the length of the slot nozzle, and the length was approximately 100 m.
X-ray diffraction measurement was performed on the obtained Fe-based amorphous alloy ribbon to obtain an X-ray diffraction pattern. The X-ray source for X-ray diffraction measurement was Cu-Kα (wavelength λ = 0.15406 nm), and the scan range was 2θ = 10 deg or more and 120 deg or less. From the shape of the X-ray diffraction pattern, it was determined whether or not a crystalline phase was formed in the metallographic structure. X-ray diffraction peaks obtained using CuKα radiation were separated into Kα1 and Kα2 radiations, and the intensity data excluding the Kα2 radiation were evaluated.
The saturation magnetic flux density and iron loss of the Fe-based amorphous alloy ribbon were measured using a single strip tester (SST). Note that the iron loss measurement conditions are a magnetic flux density of 1.3 T and a frequency of 50 Hz. Samples for iron loss measurement were collected from six locations over the entire length of a ribbon from a single lot. Each sample for iron loss measurement was a ribbon sample cut into a length of 120 mm. These ribbon samples for iron loss measurement were annealed in a magnetic field (magnetic field: 800 A/m, magnetic field applied in casting direction) at 360°C for 1 hour and subjected to measurement. The atmosphere during annealing was a nitrogen atmosphere. On the other hand, the samples for the VSM were thin pieces collected from the center portion of the width of each of the ribbon samples from the six locations.

The measurement result for the saturation magnetic flux density and iron loss represents the average value of the data from six locations, as illustrated in Tables 1A, 1B, and 1C.

[Table 1A]

No.		Chemical composition Remainder: Impurities					Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
No.		Fe (atom%)	B (atom%)	Si (atom%)	C (atom%)	P (atom%)	Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
Example	1	81.50	14.80	1.50	1.20	1.00	1.65	0.103
Example	2	80.10	17.80	1.20	0.50	0.40	1.61	0.105
Example	3	83.60	8.10	1.70	4.30	2.30	1.67	0.103
Example	4	82.80	14.20	0.10	2.10	0.80	1.66	0.104
Example	5	84.50	12.60	1.60	0.20	1.10	1.68	0.103
Example	6	82.90	10.50	1.30	4.90	0.40	1.66	0.104
Example	7	81.80	16.20	0.80	1.10	0.10	1.65	0.105
Example	8	82.30	12.50	0.70	1.10	3.40	1.66	0.104
Comparative Example	1	77.90	15.40	1.70	3.20	1.80	1.59	0.108
Comparative Example	2	86.40	9.50	1.50	1.80	0.80	1.67	0.107
Comparative Example	3	82.80	7.90	1.80	4.30	3.20	1.66	0.106
Comparative Example	4	79.00	18.10	1.00	0.70	1.20	1.60	0.106
Comparative Example	5	82.00	12.00	2.10	0.90	3.00	1.65	0.107
Comparative Example	6	83.42	14.30	1.40	0.08	0.80	1.66	0.107
Comparative Example	7	80.90	11.20	1.30	5.20	1.40	1.61	0.108
Comparative Example	8	83.02	14.40	0.80	1.70	0.08	1.66	0.108
Comparative Example	9	80.80	13.30	1.10	1.20	3.60	1.61	0.110

The underlined parts indicate that they are outside the scope of the present invention or outside the range of preferred characteristics.

[Table 1B]

No.		Chemical composition Remainder: Impurities						Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
No.		Fe (atom%)	B (atom%)	Si (atom%)	C (atom%)	P (atom%)	Mn (atom%)	Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
Example	11	83.00	14.50	1.20	0.80	0.30	0.20	1.66	0.101
Example	12	85.10	13.30	0.80	0.10	0.40	0.30	1.67	0.102
Example	13	82.60	13.80	1.80	1.30	0.40	0.10	1.65	0.101
Example	14	80.60	15.00	1.40	2.60	0.20	0.20	1.63	0.102
Example	15	82.80	13.40	1.50	0.80	1.30	0.20	1.66	0.100
Example	16	82.40	14.10	0.60	0.20	2.40	0.30	1.64	0.101
Example	17	81.30	14.20	1.50	1.80	0.80	0.40	1.63	0.090
Example	18	84.40	8.40	1.80	2.40	2.50	0.50	1.66	0.092
Example	19	80.10	15.50	0.40	1.60	1.90	0.50	1.61	0.093
Example	20	82.86	13.60	0.04	2.40	0.80	0.30	1.65	0.097
Example	21	82.40	12.30	1.90	1.80	1.20	0.40	1.65	0.096
Example	22	84.30	11.90	1.60	1.10	0.80	0.30	1.66	0.092
Example	23	81.70	10.70	1.50	4.60	1.30	0.20	1.62	0.096
Example	24	83.20	12.50	0.90	2.60	0.60	0.20	1.67	0.095
Example	25	81.60	10.60	0.80	3.30	3.40	0.30	1.65	0.098
Example	26	83.84	10.40	1.70	1.60	2.40	0.06	1.67	0.096
Example	27	82.40	13.30	0.70	1.20	1.80	0.60	1.65	0.097
Comparative Example	11	77.80	15.20	1.80	3.20	1.60	0.40	1.58	0.107
Comparative Example	12	86.20	9.50	1.50	1.80	0.80	0.20	1.68	0.110
Comparative Example	13	82.30	7.90	1.80	4.30	3.20	0.50	1.64	0.112
Comparative Example	14	78.60	18.20	1.00	0.80	1.20	0.20	1.61	0.108
Comparative Example	15	80.90	12.10	2.20	1.30	3.20	0.30	1.60	0.109
Comparative Example	16	84.62	13.20	1.60	0.08	0.40	0.10	1.67	0.110
Comparative Example	17	80.90	10.80	1.30	5.20	1.60	0.20	1.64	0.112
Comparative Example	18	82.41	14.40	0.60	2.20	0.09	0.30	1.66	0.110
Comparative Example	19	80.00	13.60	0.90	1.70	3.60	0.20	1.63	0.107
Comparative Example	20	81.36	14.10	1.80	1.30	1.40	0.04	1.64	0.106
Comparative Example	21	82.50	13.60	1.70	1.00	0.50	0.70	1.66	0.108

[Table 1C]

No.		Chemical composition Remainder: Impurities						Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
No.		Fe (atom%)	B (atom%)	Si (atom%)	C (atom%)	P (atom%)	Mn (atom%)	Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
Example	60	82.40	14.00	1.20	1.10	1.00	0.30	1.66	0.095
Example	61	83.00	13.50	1.80	0.10	1.20	0.40	1.67	0.097
Example	62	81.90	14.40	1.60	0.80	0.80	0.50	1.64	0.096
Example	63	80.70	13.50	1.50	3.30	0.60	0.40	1.62	0.097
Example	64	81.20	15.20	1.80	1.30	0.30	0.20	1.63	0.096
Example	65	80.10	13.40	0.60	2.50	3.40	0.30	1.61	0.095

As illustrated in Tables 1A, 1B, and 1C, in each of Examples 1 to 8, Examples 11 to 27, and Examples 60 to 65, since the alloy composition satisfied the range of the present disclosure, the saturation magnetic flux density was 1.60 T or higher, the iron loss (iron loss W_13/50) at a magnetic flux density of 1.3 T and a frequency of 50 Hz was 0.105 W/kg or less, and a high saturation magnetic flux density and a low iron loss could be simultaneously exhibited.
On the other hand, in each of Comparative Examples 1 to 9 and 11 to 21, since the alloy composition did not satisfy the range of the present disclosure, the iron loss (iron loss W_13/50) was more than 0.105 W/kg or the saturation magnetic flux density was less than 1.60 T.
In Comparative Examples 1 and 11, the Fe content was less than 78.00%, the saturation magnetic flux density was low, and the iron loss increased.
In Comparative Examples 2 and 12, the Fe content was more than 86.00%, and the iron loss increased.
In Comparative Examples 3 and 13, the B content was less than 8.00%, and the iron loss increased.
In Comparative Examples 4 and 14, the B content was more than 18.0%, and the iron loss increased.
In Comparative Examples 5 and 15, the Si content was more than 2.0%, and the iron loss increased.
In Comparative Examples 6 and 16, the C content was less than 0.10%, and the iron loss increased.
In Comparative Examples 7 and 17, the C content was more than 5.00%, and the iron loss increased.
In Comparative Examples 8 and 18, the P content was less than 0.10%, and the iron loss increased.
In Comparative Examples 9 and 19, the P content was more than 3.50%, and the iron loss increased.
In Comparative Example 20, the Mn content was less than 0.05%, and the iron loss increased.
In Comparative Example 21, the Mn content was more than 0.60%, and the iron loss increased.
Note that, as a result of X-ray diffraction measurement performed on the Fe-based amorphous alloy ribbons, it cannot be said that a crystalline phase was formed in the metallographic structure in all of Examples 1 to 8, Examples 11 to 27, Examples 60 to 65, and Comparative Examples 1 to 9, and 11 to 21 from the fact that a clear diffraction peak was not observed, and the entire structure was amorphous.

(Example 2)

With respect to the alloy illustrated in Example 1 of Table 1A and the alloys illustrated in Example 11 and Example 24 of Table 1B, the ribbons were cast using alloys having various components in which Fe was substituted in part with at least one of Ni, Cr, and Co under the same device and conditions as those in Example 1. Note that specific components of the used alloys are illustrated in Tables 2A and 2B. As a result, the obtained ribbon had a sheet thickness, a sheet width, and a length of about 20 µm, 10 mm, and about 100 m, respectively.

The saturation magnetic flux density and iron loss of the obtained ribbon were evaluated. The sample collection method and measurement conditions used for these characterizations were the same as those in Example 1. The measurement results are illustrated in Tables 2A and 2B. Note that the display formats of Tables 2A and 2B are the same as those in Tables 1A and 1B.

[Table 2A]

No.		Chemical composition Remainder: Impurities								Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
No.		Fe (atom%)	Ni (atom%)	Cr (atom%)	Co (atom%)	B (atom%)	Si (atom%)	C (atom%)	P (atom%)	Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
Example	31	80.50	1.00			14.80	1.50	1.20	1.00	1.64	0.104
Example	32	78.50		3.00		14.80	1.50	1.20	1.00	1.65	0.103
Example	33	79.50			2.00	14.80	1.50	1.20	1.00	1.62	0.104
Example	34	76.50	3.00	2.00		14.80	1.50	1.20	1.00	1.64	0.104
Example	35	75.50	3.00		3.00	14.80	1.50	1.20	1.00	1.66	0.102
Example	36	74.50		3.00	4.00	14.80	1.50	1.20	1.00	1.66	0.102
Example	37	72.50	2.00	4.00	3.00	14.80	1.50	1.20	1.00	1.65	0.103

[Table 2B]

No.		Chemical composition Remainder: Impurities									Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
No.		Fe (atom%)	Ni (atom%)	Cr (atom%)	Co (atom%)	B (atom%)	Si (atom%)	C (atom%)	P (atom%)	Mn (atom%)	Saturation magnetic flux density Bs (T)	Iron loss W_13/50 (W/kg)
Example	41	82.00	1.00			14.50	1.20	0.80	0.30	0.20	1.65	0.104
Example	42	80.00		3.00		14.50	1.20	0.80	0.30	0.20	1.63	0.105
Example	43	81.00			2.00	14.50	1.20	0.80	0.30	0.20	1.65	0.103
Example	44	78.00	3.00	2.00		14.50	1.20	0.80	0.30	0.20	1.63	0.104
Example	45	77.00	3.00		3.00	14.50	1.20	0.80	0.30	0.20	1.67	0.102
Example	46	76.00		3.00	4.00	14.50	1.20	0.80	0.30	0.20	1.67	0.102
Example	47	74.00	2.00	4.00	3.00	14.50	1.20	0.80	0.30	0.20	1.66	0.103
Example	48	82.20	1.00			12.50	0.90	2.60	0.60	0.20	1.66	0.096
Example	49	80.20		3.00		12.50	0.90	2.60	0.60	0.20	1.64	0.097
Example	50	81.20			2.00	12.50	0.90	2.60	0.60	0.20	1.68	0.094
Example	51	78.20	3.00	2.00		12.50	0.90	2.60	0.60	0.20	1.65	0.096
Example	52	77.20	3.00		3.00	12.50	0.90	2.60	0.60	0.20	1.66	0.095
Example	53	76.20		3.00	4.00	12.50	0.90	2.60	0.60	0.20	1.67	0.095
Example	54	74.20	2.00	4.00	3.00	12.50	0.90	2.60	0.60	0.20	1.66	0.095

As is clear from the results of Examples 31 to 37 and 41 to 54 in Tables 2A and 2B, it was found that even in a case where Fe was substituted in part with at least one of Ni, Cr, and Co in a range of 10.0 atom% or less, the saturation magnetic flux density was 1.60 T or higher, and the iron loss W_13/50 was stably maintained to 0.105 W/kg or less. Moreover, in any of the samples, no clear diffraction peak was observed in the X-ray diffraction measurement, and it was confirmed that the samples were amorphous.
As is clear from the above examples, according to the Fe-based amorphous alloy and the Fe-based amorphous alloy ribbon of the present disclosure, by optimizing the contents of B, Si, C and P, along with increasing the Fe content to 78.00% or more, the iron loss (iron loss W_13/50) at a magnetic flux density of 1.3 T and a frequency of 50 Hz is 0.105 W/kg or less, the saturation magnetic flux density is 1.60 T or higher, and excellent soft magnetic properties can be exhibited, and it was demonstrated that suitable application for a core of a power transformer or a high-frequency transformer can be achieved.

Claims

An Fe-based amorphous alloy comprising, in atom%:
B: 8.0% or more and 18.0% or less;

Si: 0% or more and 2.0% or less;

C: 0.10% or more and 5.00% or less;

P: 0.10% or more and 3.50% or less;

Mn: 0% or more and 0.60% or less;

Fe: 78.00% or more and 86.00% or less, and

a remainder including impurities, wherein

a microstructure of the Fe-based amorphous alloy is amorphous.
The Fe-based amorphous alloy according to claim 1 comprising, in atom%,
Mn: 0.05% or more and 0.60% or less.
The Fe-based amorphous alloy according to claim 1 comprising, in atom%:
C: 1.00% or more and 5.00% or less; and

Mn: 0.05% or more and 0.60% or less.
The Fe-based amorphous alloy according to claim 1 comprising, in atom%:
C: 2.00% or more and 5.00% or less; and

Mn: 0.05% or more and 0.60% or less.
The Fe-based amorphous alloy according to claim 1 comprising, in atom%:
P: 0.50% or more and 3.50% or less; and

Mn: 0.05% or more and 0.60% or less.
The Fe-based amorphous alloy according to claim 1 comprising, in atom%:
C: 1.00% or more and 5.00% or less;

P: 0.50% or more and 3.50% or less; and

Mn: 0.05% or more and 0.60% or less.
The Fe-based amorphous alloy according to claim 1 comprising, in atom%:
C: 2.00% or more and 5.00% or less;

P: 0.50% or more and 3.50% or less; and

Mn: 0.05% or more and 0.60% or less.
The Fe-based amorphous alloy according to any one of claims 1 to 7, wherein Fe is substituted with at least one or more elements of Ni, Cr, and Co in a range of 10.0 atom% or less.
The Fe-based amorphous alloy according to any one of claims 1 to 7, wherein an iron loss W_13/50 upon magnetization at a frequency of 50 Hz and a magnetic flux density of 1.3 T is 0.105 W/kg or less, and a saturation magnetic flux density is 1.60 T or higher.
The Fe-based amorphous alloy according to claim 8, wherein an iron loss W_13/50 upon magnetization at a frequency of 50 Hz and a magnetic flux density of 1.3 T is 0.105 W/kg or less, and a saturation magnetic flux density is 1.60 T or higher.
The Fe-based amorphous alloy according to claim 10, wherein the iron loss W_13/50 is 0.097 W/kg or less.
An Fe-based amorphous alloy ribbon comprising the Fe-based amorphous alloy according to any one of claims 1 to 7.
An Fe-based amorphous alloy ribbon comprising the Fe-based amorphous alloy according to claim 8.
An Fe-based amorphous alloy ribbon comprising the Fe-based amorphous alloy according to claim 9.
An Fe-based amorphous alloy ribbon comprising the Fe-based amorphous alloy according to claim 10.
An Fe-based amorphous alloy ribbon comprising the Fe-based amorphous alloy according to claim 11.