Soft magnetic alloy ribbon, manufacturing method of soft magnetic alloy ribbon, and magnetic core

Abstract

To provide a soft magnetic alloy ribbon that allows manufacturing of a magnetic core that has low iron loss and the optimized distribution of in-plane stress after laser scribe processing, and provide a magnetic core including such a soft magnetic alloy ribbon.SOLUTION: A soft magnetic alloy ribbon is formed of an Fe-based soft magnetic alloy, and has a first laser peening trace row and a second laser peening trace row that are formed of a plurality of laser peening traces in a row in a first direction and are arranged adjacent to each other in a second direction. When a straight line at an equal separation distance from the rows is defined as a central line, a circle located around the center of the laser peening traces constituting the first laser peening trace row and having a first radius shorter than the separation distance as a first reference circle, a straight line passing through the center and in parallel to the second direction as a reference line, an in-plane stress at the intersection of the reference line and the central line as σ0, and an in-plane stress on the circumference of the first reference circle as σ1, the ribbon satisfies the relationship σ0<σ1.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a soft magnetic alloy ribbon. , soft magnetic alloy ribbon manufacturing method and magnetic cores. [Background technology]

[0002] Patent Document 1 discloses a soft magnetic alloy ribbon manufactured by a rapid solidification method, which has on its surface recesses formed by irradiating with laser light and protrusions formed around the recesses. It also discloses a wound magnetic core formed by winding the soft magnetic alloy ribbon so that the recesses are on the outside.

[0003] When a soft magnetic alloy ribbon is heat-treated while a magnetic field is applied in the longitudinal direction, magnetic domains are formed along the longitudinal direction in an anti-parallel manner with a 180° domain wall sandwiched between them.

[0004] Here, if the soft magnetic alloy ribbon is irradiated with a laser beam in advance, finer magnetic domains are formed compared to when the laser beam is not irradiated. In other words, the laser beam irradiation significantly refines the magnetic domains through heat treatment. By refining the magnetic domains in this way, it is possible to reduce eddy current loss and obtain a magnetic core with low iron loss.

[0005] Furthermore, Patent Document 1 discloses that iron loss can be particularly reduced by optimizing the height of the protrusions and the ratio of the depth of the recesses to the thickness of the ribbon. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-199506 Summary of the Invention [Problem to be solved by the invention]

[0007] Patent Document 1 discloses optimal conditions for the depth of recesses and the height of protrusions formed by laser light irradiation, i.e., laser scribing. However, the subdivision of magnetic domains is significantly affected by the alloy composition of the ribbon and the associated mechanical properties of the ribbon. For this reason, there are cases where the magnetic domains cannot be sufficiently subdivided simply by optimizing the conditions of the laser scribing. Therefore, there is a demand for magnetic domain subdivision that is independent of the alloy composition of the ribbon. [Means for solving the problem]

[0008] The soft magnetic alloy ribbon according to the application example of the present invention is A ribbon made of an Fe-based soft magnetic alloy, a first laser peening mark row and a second laser peening mark row that are arranged adjacent to each other in a second direction intersecting the first direction; The width is between 5mm and 500mm, The thickness is 1 μm or more and 40 μm or less, the Fe-based soft magnetic alloy is an Fe-Si-B alloy or an Fe-Si-BC alloy, The Fe-based soft magnetic alloy contains at least one of an amorphous structure and a nanocrystalline structure in a total amount of 50% by volume or more, a straight line that is equally spaced from the first laser peening mark row and the second laser peening mark row is defined as an intermediate line; a circle that is positioned around the center of the laser peening marks that constitute the first laser peening mark row and has a first radius that is shorter than the separation distance is defined as a first reference circle; a circle that is positioned around the center of the laser peening marks that constitute the second laser peening mark row and has a second radius that is shorter than the separation distance is defined as a second reference circle; a straight line that passes through the center of the laser peening marks that constitute the first laser peening mark row and the center of the laser peening marks that constitute the second laser peening mark row and is parallel to the second direction is set as a reference line; The in-plane stress at the intersection of the reference line and the intermediate line is σ0, The in-plane stress on the circumference of the first reference circle is defined as σ1, When the in-plane stress on the circumference of the second reference circle is σ2, The relationships σ0<σ1 and σ0<σ2 are satisfied, the ratio of σ1 / σ0 and the ratio of σ2 / σ0 are each greater than 1 and equal to or less than 5; The in-plane stress σ0, the in-plane stress σ1, and the in-plane stress σ2 are each 50 MPa or more and 1000 MPa or less, The interval between the first laser peening mark row and the second laser peening mark row is 1 mm or more and 40 mm or less. the law of nature, The spot spacing between the laser peening marks is 1.0 mm or less, The spot diameter of the laser peening mark is 0.010 mm or more and 0.30 mm or less, The spot depth of the laser peening mark is 0.0020 mm or more and 0.15 mm or less. .

[0009] A method for producing a soft magnetic alloy ribbon according to an application example of the present invention includes the steps of: A method for producing a soft magnetic alloy ribbon according to an application example of the present invention, comprising: preparing a material ribbon made of a soft magnetic alloy; forming the laser peening marks on the material ribbon by performing laser processing on the material ribbon with a pulsed laser beam; and The energy density of the pulsed laser light is 0.01 J / mm 2 More than 1.50J / mm 2 is as follows: the pulse width of the pulsed laser light is 50 nanoseconds or more; the diameter of the pulsed laser beam is 0.010 mm or more and 0.30 mm or less; adjusting the in-plane stress σ1 and the in-plane stress σ2 based on the energy density of the pulsed laser beam or the pulse width of the pulsed laser beam; The in-plane stress σ0 is adjusted based on the interval between the first row of laser peening marks and the second row of laser peening marks. The magnetic core according to the application example of the present invention is The soft magnetic alloy ribbon according to the application example of the present invention is included. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view schematically showing a soft magnetic alloy ribbon according to an embodiment. [Figure 2] FIG. 2 is an enlarged view of part A in FIG. [Figure 3] FIG. 3 is a cross-sectional view of the laser peening marks shown in FIG. 2. [Figure 4] 2 is an enlarged plan view showing a first surface of the soft magnetic alloy ribbon shown in FIG. 1, and is a diagram schematically showing magnetic domains and domain walls of the soft magnetic alloy ribbon. FIG. [Figure 5] FIG. 10 is an enlarged plan view showing a first surface of a soft magnetic alloy ribbon according to a first modification, and is a diagram schematically showing magnetic domains and domain walls of the soft magnetic alloy ribbon. [Figure 6] FIG. 10 is an enlarged plan view showing a first surface of a soft magnetic alloy ribbon according to a second modification, and is a diagram schematically showing magnetic domains and domain walls of the soft magnetic alloy ribbon. [Figure 7] 1 is a flowchart illustrating an example of a method for manufacturing a soft magnetic alloy ribbon. [Figure 8] FIG. 2 is a schematic diagram showing a magnetic core according to an embodiment. [Figure 9] 1 is a graph created by plotting data on the in-plane stresses σ0 and σ1a of the soft magnetic alloy ribbons of each sample number shown in Table 1 in an orthogonal coordinate system with the in-plane stress σ1a on the horizontal axis and the in-plane stress σ0 on the vertical axis. [Figure 10] 1 is a graph created by plotting data on the in-plane stresses σ0 and σ1b of the soft magnetic alloy ribbons of each sample number shown in Table 3 in an orthogonal coordinate system with the in-plane stress σ1b on the horizontal axis and the in-plane stress σ0 on the vertical axis. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A soft magnetic alloy ribbon and a magnetic core according to the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings.

[0012] 1.Soft magnetic alloy ribbon The soft magnetic alloy ribbon according to the embodiment is a ribbon made of a soft magnetic alloy. A soft magnetic alloy is an alloy that exhibits soft magnetism. For example, a plurality of soft magnetic alloy ribbons are stacked to form a laminate. Such a laminate is used for a magnetic core of a transformer or the like.

[0013] Fig. 1 is a perspective view schematically showing a soft magnetic alloy ribbon according to an embodiment. Fig. 2 is an enlarged view of a portion A in Fig. 1. In Fig. 1, the width direction of the soft magnetic alloy ribbon 1 is designated X, the length direction is designated Y, and the thickness direction is designated Z. In Fig. 1, these three directions are indicated by arrows. Each direction described below includes both the direction from the base end to the tip end of the arrow and the direction from the tip end to the base end.

[0014] In FIG. 1, the soft magnetic alloy ribbon 1 has a length L, a width W, and a thickness t. The ribbon has a first surface 11 and a second surface 12 that are opposite surfaces to each other, and the distance between the first surface 11 and the second surface 12, i.e., the thickness t of the soft magnetic alloy ribbon 1, is sufficiently shorter than the length L and width W of the soft magnetic alloy ribbon 1.

[0015] The thickness t of the soft magnetic alloy ribbon 1 is not particularly limited, but is preferably 1 μm or more and 40 μm or less, and more preferably 5 μm or more and 30 μm or less. The soft magnetic alloy ribbon 1 having such a thickness t achieves both sufficient mechanical strength and reduced eddy current loss. This allows the soft magnetic alloy ribbon 1 to be wound with a small bending radius, enabling the production of a small-sized magnetic core with low iron loss.

[0016] The width W of the soft magnetic alloy ribbon 1 is not particularly limited because it is often determined by the manufacturing device and manufacturing method of the soft magnetic alloy ribbon 1, but is preferably 5 mm or more, more preferably 10 mm or more and 500 mm or less, and even more preferably 20 mm or more and 300 mm or less.

[0017] The length L of the soft magnetic alloy ribbon 1 is determined when the soft magnetic alloy ribbon 1 is manufactured, and is therefore not particularly limited as long as it is longer than the width W of the soft magnetic alloy ribbon 1. When the soft magnetic alloy ribbon is wound to be used for manufacturing a magnetic core, the length L of the soft magnetic alloy ribbon is, for example, preferably 5 times or more, and more preferably 10 times or more, the width W of the soft magnetic alloy ribbon 1.

[0018] Examples of soft magnetic alloys include Fe-based soft magnetic alloys such as Fe-Si-B, Fe-Si-BC, Fe-Si-B-Cr-C, Fe-Si-Cr, Fe-B, Fe-BC, Fe-PC, Fe-Co-Si-B, Fe-Si-B-Nb, Fe-Si-B-Nb-Cu, and Fe-Zr-B. Fe-based soft magnetic alloys have excellent soft magnetic properties and high saturation magnetic flux density, and are therefore useful as a constituent material of the soft magnetic alloy ribbon 1 used in magnetic cores, etc.

[0019] The soft magnetic alloy may contain nanocrystals. Nanocrystals refer to a crystalline structure having a grain size of 1.0 nm or more and 30.0 nm or less. By containing such nanocrystals, the soft magnetic properties of the soft magnetic alloy can be further improved. In other words, it is possible to realize a soft magnetic alloy ribbon 1 that more effectively achieves both low coercive force and high magnetic permeability.

[0020] In the soft magnetic alloy ribbon 1, at least one of the amorphous structure and the nanocrystalline structure is preferably contained in a total amount of 50% by volume or more, more preferably 70% by volume or more. This allows the soft magnetic alloy ribbon 1 to exhibit particularly good soft magnetism. In addition, the soft magnetic alloy ribbon 1 may contain a crystalline structure. The crystalline structure refers to a structure composed of crystal grains having a grain size of more than 30.0 nm.

[0021] Among the aforementioned series, Fe-based soft magnetic alloys are particularly preferably Fe-Si-B alloys or Fe-Si-BC alloys. Of these, Fe-Si-B alloys are composed of Fe, Si, B, and impurities. Fe-Si-B alloys have a chemical composition in which, when the total content of Fe, Si, and B is taken as 100 atomic %, the Fe content is 78 atomic % or more, the B content is 11 atomic % or more, and the total content of Si and B is 17 atomic % or more and 22 atomic % or less.

[0022] Fe is a metal element with a large magnetic moment, and influences the magnetic flux density of the soft magnetic alloy ribbon 1. The Fe content is preferably 78 atomic % or more and 82 atomic % or less.

[0023] Si and B affect the amorphous-forming ability of Fe-based soft magnetic alloys. The Si content is preferably 2.0 atomic % or more and 6.0 atomic % or less, and more preferably 3.5 atomic % or more and 6.0 atomic % or less. The B content is preferably 12 atomic % or more and 16 atomic % or less, and more preferably 13 atomic % or more and 16 atomic % or less. As mentioned above, the total content of Si and B is preferably 17 atomic % or more and 22 atomic % or less.

[0024] In an Fe-based soft magnetic alloy having such a chemical composition, by setting the Fe content within the above range, it is possible to increase the amorphous-forming ability and the magnetic flux density. Therefore, it is possible to realize a soft magnetic alloy ribbon 1 that exhibits excellent soft magnetic properties derived from the amorphous structure or nanocrystals formed from the amorphous structure and has a high saturation magnetic flux density. Furthermore, by setting the total content of Si and B within the above range, it is possible to realize a soft magnetic alloy ribbon 1 in which iron loss is sufficiently reduced.

[0025] As shown in FIGS. 1 and 2, the soft magnetic alloy ribbon 1 according to the embodiment has a laser peening mark row 16 formed on the first surface 11 and consisting of a plurality of laser peening marks 15 arranged in a row.

[0026] In this specification, the direction in which the rows of laser peening marks 15 are formed is referred to as the "first direction α." In this embodiment, as an example, the first direction α and the width direction X are parallel to each other. In this specification, "parallel" refers to a state in which the angle between the two directions is 10° or less. However, the relationship between the first direction α and the width direction X is not limited to this, and the first direction α may be non-parallel to the width direction X.

[0027] As shown in FIG. 1 , the soft magnetic alloy ribbon 1 has a plurality of laser peening mark rows 16. The plurality of laser peening mark rows 16 shown in FIG. 1 are aligned in a second direction β that intersects with the first direction α. ​​In the present embodiment, as an example, the second direction β is perpendicular to the first direction α. ​​However, the relationship between the first direction α and the second direction β is not limited thereto, and the intersecting angle between the first direction α and the second direction β is preferably 60° or more and 90° or less, and more preferably 75° or more and 90° or less. The intersecting angle between the first direction α and the second direction β refers to the smallest angle between the first direction α and the second direction β.

[0028] Fig. 3 is a cross-sectional view of the laser peening mark 15 shown in Fig. 2. Fig. 4 is an enlarged plan view showing the first surface 11 of the soft magnetic alloy ribbon 1 shown in Fig. 1, and is a diagram schematically showing the magnetic domains 3 and the domain walls 2 of the soft magnetic alloy ribbon 1.

[0029] 2, in laser peening mark row 16, laser peening marks 15 that are substantially circular in plan view are lined up in a row along first direction α. ​​In this specification, a straight line drawn so as to connect the centers of laser peening marks 15 lined up in a row along first direction α is defined as laser peening mark row 16. When the center positions are not lined up in a row and vary slightly, a straight line drawn at a position that evens out the amount of deviation is defined as laser peening mark row 16.

[0030] The laser peening marks 15 are processing marks formed by irradiating the first surface 11 with laser light, and refer to depressions as shown in Fig. 3 that are obtained when the soft magnetic alloy is melted by the energy of the laser light. The process of forming the laser peening marks 15 is called laser scribing.

[0031] As shown in FIG. 4 , the soft magnetic alloy ribbon 1 has a domain wall 2. The domain wall 2 extends linearly along a third direction γ that intersects with the first direction α. ​​In the present embodiment, as an example, the third direction γ and the first direction α are perpendicular to each other. Therefore, in the present embodiment, the third direction γ is parallel to the second direction β. However, the relationship between the first direction α and the third direction γ is not limited thereto, and the third direction γ may be non-parallel to the second direction β. In addition, the crossing angle between the first direction α and the third direction γ is preferably 60° or more and 90° or less, and more preferably 75° or more and 90° or less. The crossing angle between the first direction α and the third direction γ refers to the smallest angle between the first direction α and the third direction γ.

[0032] Furthermore, the domain walls 2 are located at the boundaries between magnetic domains 3 adjacent to each other in the second direction β. The magnetic domains 3 shown in FIG. 4 are strip-shaped with their major axes aligned with the first direction α. ​​The soft magnetic alloy ribbon 1 has many domain walls 2, which subdivides the magnetic domains 3, i.e., divides the magnetic domains 3 into smaller domains. As a result, the domain walls 2 move more easily under an AC magnetic field, and eddy current loss in the soft magnetic alloy ribbon 1 is reduced. Furthermore, since the magnetic domains 3 have a shape with their major axes aligned with the first direction α, the easy axis of magnetization is aligned with the first direction α, and the hard axis of magnetization is aligned in a direction perpendicular to the first direction α. The laser peening marks 15 and the domain walls 2 will be described in more detail below.

[0033] 1.1.Laser peening marks 1.1.1.Line Spacing The distance between the laser peening mark rows 16 shown in FIG. 1 is defined as a line distance d1. The line distance d1 is preferably 1 mm or more and 40 mm or less, more preferably 1 mm or more and 30 mm or less, and further preferably 2 mm or more and 20 mm or less. When the line distance d1 is within the above range, the arrangement density of the laser peening mark rows 16 in the soft magnetic alloy ribbon 1 can be optimized. As a result, the magnetic domains 3 can be favorably subdivided, and the iron loss of the soft magnetic alloy ribbon 1 can be further reduced.

[0034] If the line spacing d1 is below the lower limit, depending on conditions such as the composition of the soft magnetic alloy, the area where the amorphous material contained in the soft magnetic alloy ribbon 1 crystallizes or the area where the nanocrystals enlarge increases may decrease the soft magnetic properties, resulting in an increase in the iron loss of the soft magnetic alloy ribbon 1. On the other hand, if the line spacing d1 is above the upper limit, depending on other arrangement conditions of the laser peening marks 15 and the laser peening mark arrays 16, the magnetic domains 3 may not be subdivided sufficiently, and the iron loss of the soft magnetic alloy ribbon 1 may not be reduced sufficiently.

[0035] The adjacent laser peening mark rows 16 are preferably substantially parallel to each other, but may be non-parallel to each other. Also, the laser peening mark rows 16 may have a mixture of parallel and non-parallel portions.

[0036] The first direction α shown in FIG. 1 is parallel to the width direction X as described above, but may include non-parallel portions.

[0037] The line spacing d1 is the distance between the centers of the laser peening marks 15 measured in a middle portion of the width W of the soft magnetic alloy ribbon 1. The middle portion refers to a region having a width half the width W and centered at the middle point of the width W. Therefore, the laser peening mark row 16 may extend over the entire width W of the soft magnetic alloy ribbon 1 or over only a part of the width W, as long as at least a part of the laser peening mark row 16 is provided in this middle portion.

[0038] The intervals between the laser peening mark rows 16 may be constant over the entire soft magnetic alloy ribbon 1 or may vary partially. That is, when the intervals between the laser peening mark rows 16 are measured at a plurality of locations in the middle of the width W of one soft magnetic alloy ribbon 1, the measured values ​​may be the same or different from one another. In the latter case, the average value of five measured values ​​is set to the line interval d1 of the soft magnetic alloy ribbon 1.

[0039] Laser peening marks 15 may be provided on only one of first surface 11 and second surface 12, or on both. When provided on both, it is sufficient that the range of line spacing d1 described above is satisfied when laser peening marks 15 provided on second surface 12 are projected onto first surface 11 and the projected laser peening marks 15 and the laser peening marks 15 provided on first surface 11 are combined.

[0040] 1.1.2.Spot Spacing The distance between the laser peening marks 15 in the laser peening mark row 16 shown in FIG. 1 is defined as a spot distance d2. The spot distance d2 is set shorter than the line distance d1 described above, and is preferably 1.0 mm or less, more preferably 0.10 mm or more and 1.0 mm or less, even more preferably 0.15 mm or more and 0.75 mm or less, and particularly preferably 0.20 mm or more and 0.50 mm or less. When the spot distance d2 is within the above range, the arrangement density of the laser peening marks 15 in the laser peening mark row 16 can be optimized. As a result, the magnetic domains 3 can be favorably subdivided, and the iron loss of the soft magnetic alloy ribbon 1 can be further reduced.

[0041] If the spot interval d2 is below the lower limit, depending on conditions such as the composition of the soft magnetic alloy, amorphous matter contained in the soft magnetic alloy ribbon 1 may crystallize or nanocrystals may become enlarged, resulting in a decrease in soft magnetic properties and an increase in iron loss of the soft magnetic alloy ribbon 1. On the other hand, if the spot interval d2 is above the upper limit, depending on other arrangement conditions of the laser peening marks 15 and the laser peening mark arrays 16, subdivision of the magnetic domains 3 may be insufficient, making it impossible to sufficiently reduce the iron loss of the soft magnetic alloy ribbon 1.

[0042] The spot interval d2 is the distance between the centers of adjacent laser peening marks 15 in one laser peening mark row 16, measured at the middle of the width W of the soft magnetic alloy ribbon 1. The center of the laser peening mark 15 is the center of a perfect circle inscribed in the laser peening mark 15.

[0043] The intervals between the laser peening marks 15 may be constant over the entire soft magnetic alloy ribbon 1 or may vary partially. That is, when the intervals between the laser peening marks 15 are measured at a plurality of locations in the middle of the width W of one soft magnetic alloy ribbon 1, the measured values ​​may be the same or different from one another. In the latter case, the average value of five measured values ​​is set as the spot interval d2 of the soft magnetic alloy ribbon 1.

[0044] When laser peening marks 15 are provided on both the first surface 11 and the second surface 12, the range of the spot interval d2 described above may be satisfied when the laser peening marks 15 provided on the second surface 12 are projected onto the first surface 11 and the projected laser peening marks 15 and the laser peening marks 15 provided on the first surface 11 are combined.

[0045] 1.1.3.Spot diameter The diameter of the laser peening marks 15 shown in Fig. 2 and Fig. 3 is defined as a spot diameter d3. The spot diameter d3 is preferably 0.010 mm or more and 0.30 mm or less, more preferably 0.020 mm or more and 0.25 mm or less, and further preferably 0.030 mm or more and 0.20 mm or less. When the spot diameter d3 is within the above range, the magnetic domains 3 can be successfully subdivided by the laser peening marks 15. In addition, a decrease in the mechanical strength of the soft magnetic alloy ribbon 1 due to the formation of the laser peening marks 15 can be suppressed.

[0046] If the spot diameter d3 is below the lower limit, the magnetic domains 3 may not be sufficiently subdivided depending on other arrangement conditions of the laser peening marks 15 and the laser peening mark arrays 16, and the iron loss of the soft magnetic alloy ribbon 1 may not be sufficiently reduced. On the other hand, if the spot diameter d3 is above the upper limit, the mechanical strength of the soft magnetic alloy ribbon 1 may be reduced.

[0047] The spot diameter d3 is the average value of the circle-equivalent diameters of 10 or more laser peening marks 15 measured at the middle part of the width W of the soft magnetic alloy ribbon 1. The circle-equivalent diameter is the diameter of a perfect circle having the same area as the laser peening mark 15 when the first surface 11 is viewed in plan.

[0048] The equivalent circle diameters of the laser peening marks 15 may be the same as or different from each other.

[0049] 1.1.4.Spot Depth The depth of the laser peening marks 15 shown in Fig. 3 is defined as a spot depth d4. The spot depth d4 is preferably 0.0020 mm or more and 0.15 mm or less, more preferably 0.0030 mm or more and 0.10 mm or less, and further preferably 0.0040 mm or more and 0.050 mm or less. When the spot depth d4 is within the above range, the magnetic domains 3 can be sufficiently subdivided by the laser peening marks 15. In addition, a decrease in the mechanical strength of the soft magnetic alloy ribbon 1 due to the formation of the laser peening marks 15 can be suppressed.

[0050] If the spot depth d4 is below the lower limit, the magnetic domains 3 may not be sufficiently subdivided depending on other arrangement conditions of the laser peening marks 15 and the laser peening mark arrays 16, and the iron loss of the soft magnetic alloy ribbon 1 may not be sufficiently reduced. On the other hand, if the spot depth d4 is above the upper limit, the mechanical strength of the soft magnetic alloy ribbon 1 may be reduced.

[0051] The spot depth d4 is the average value of the depths of 10 or more laser peening marks 15 measured in the middle of the width W of the soft magnetic alloy ribbon 1.

[0052] The depths of the laser peening marks 15 may be the same or different from each other.

[0053] 1.1.5.Number density The number density D of the laser peening marks 15 can be calculated by using the line interval d1 [mm] and the spot interval d2 [mm] in the soft magnetic alloy ribbon 1. Specifically, the number density D of the laser peening marks 15 is expressed as (1 / d1) × (1 / d2). The number density D is an index representing the arrangement density based on the number of laser peening marks 15. The number density D of the laser peening marks 15 is 0.05 marks / mm 2 More than 0.50 pieces / mm 2 It is preferable that the number of particles is 0.10 pieces / mm or less. 2 More than 0.40 pieces / mm 2 It is more preferable that the number of particles is 0.15 particles / mm or less. 2 More than 0.35 pieces / mm 2 If the number density D is within the above range, the subdivision of the magnetic domains 3 by the laser peening marks 15 can be further optimized, and the iron loss of the soft magnetic alloy ribbon 1 can be further reduced.

[0054] If the number density D is below the lower limit, it may be difficult to sufficiently reduce the iron loss of the soft magnetic alloy ribbon 1. On the other hand, if the number density D is above the upper limit, damage such as breakage may easily occur in the soft magnetic alloy ribbon 1 when the soft magnetic alloy ribbon 1 is bent with a small bending radius.

[0055] The number density D is calculated from a region in the middle of the width W of the soft magnetic alloy ribbon 1, where the laser peening mark row 16 is arranged and where the length in the longitudinal direction Y is 30 cm or more. When the length L of the soft magnetic alloy ribbon 1 is less than 30 cm, the number density D is calculated from the entire length.

[0056] When laser peening marks 15 are provided on both the first surface 11 and the second surface 12, it is sufficient that the range of the number density D is satisfied when the laser peening marks 15 provided on the second surface 12 are projected onto the first surface 11 and the projected laser peening marks 15 and the laser peening marks 15 provided on the first surface 11 are combined.

[0057] 1.2. Domain wall As described above, the soft magnetic alloy ribbon 1 has the domain walls 2. The relationship between the positions of the domain walls 2 and the laser peening marks 15 is not particularly limited. In this embodiment, as shown in FIG. 4 , the positions of the domain walls 2 and the laser peening marks 15 coincide with each other in the width direction X, but as will be described later, these positions may be shifted from each other.

[0058] The domain wall 2 is a 180° domain wall. A 180° domain wall refers to a domain wall that exists between adjacent magnetic domains when the magnetization directions of those domains are opposite to each other. Therefore, as shown in FIG. 4, the magnetization directions of adjacent magnetic domains 3 that are sandwiched between the domain wall 2 are opposite to each other. In FIG. 4, the magnetization direction of each magnetic domain 3 is indicated by an outline arrow. In FIG. 4, of the multiple laser peening mark rows 16, two adjacent ones are referred to as a first laser peening mark row 161 and a second laser peening mark row 162.

[0059] The width of the domain wall 2, i.e., the length of the domain wall 2 in the first direction α, is not particularly limited, but is preferably 50 nm or less, more preferably 2 nm to 40 nm, and even more preferably 10 nm to 30 nm, which makes the domain wall 2 particularly susceptible to movement by an external magnetic field.

[0060] The width of the magnetic domain 3 after subdivision, i.e., the length of the magnetic domain 3 in the first direction α, is not particularly limited, but is preferably 5 mm or less, more preferably 0.05 mm or more and 3 mm or less, and even more preferably 0.1 mm or more and 1 mm or less.

[0061] 1.3. In-plane stress In the soft magnetic alloy ribbon 1, the in-plane stress σ0 at the middle position MP differs from the in-plane stress σ1 at the proximity position NP1 close to the first laser peening mark row 161. Specifically, the relationship σ0<σ1 holds.

[0062] The intermediate position MP is a position where an intermediate line CL, which is located at an equal distance α0 from the first laser peening mark row 161 and the second laser peening mark row 162, intersects with a reference line DL. The intermediate line CL is a straight line parallel to the first direction α. ​​The reference line DL is a straight line that passes through the centers of the laser peening marks 15 that make up the first laser peening mark row 161 and is parallel to the second direction β.

[0063] The close position NP1 is a position on the circumference of a first reference circle DC1 at a first radius r1 from the center of the laser peening marks 15 that make up the first laser peening mark row 161. The first radius r1 is a distance shorter than the separation distance α0 described above, and is a distance defined as r1 = d2 / 2. Note that d2 used in defining the first radius r1 is the distance between the laser peening marks 15 that make up the first laser peening mark row 161 (spot distance d2).

[0064] It is believed that such an in-plane stress distribution was caused by the laser scribing process. The in-plane stress is a scalar quantity called von Mises stress. One cause of the in-plane stress distribution is that at the near position NP1, the formation of the laser peening marks 15 compresses the surrounding soft magnetic alloy, resulting in compressive stress. Another cause is that at the intermediate position MP, which is far from the laser peening marks 15, this compressive stress is relatively small. It is believed that by optimizing the in-plane stress distribution in this way, the energy required for AC magnetization is reduced, and iron loss in the soft magnetic alloy ribbon 1 can be reduced.

[0065] As described above, the proximity position NP1 is a position on the circumference of the first reference circle DC1, and is not limited to a single point. In Fig. 4, as an example, the intersection of the first reference circle DC1 and the reference line DL is referred to as the "proximity position NP1a," and the intersection of the first reference circle DC1 and the first laser peening mark row 161 is referred to as the "proximity position NP1b." The in-plane stress σ1 at the proximity position NP1a is particularly referred to as the "in-plane stress σ1a," and the in-plane stress σ1 at the proximity position NP1b is particularly referred to as the "in-plane stress σ1b."

[0066] In this case, the relationships σ0<σ1a and σ0<σ1b are established. Note that the in-plane stress σ1a and the in-plane stress σ1b may be equal to or different from each other.

[0067] In the soft magnetic alloy ribbon 1, the in-plane stress σ0 at the middle position MP is different from the in-plane stress σ2 at the adjacent position NP2 close to the second laser peening mark row 162. Specifically, the relationship σ0<σ2 holds.

[0068] The proximity position NP2 is a position where the reference line DL intersects with a second reference circle DC2 at a second radius r2 from the center of the laser peening marks 15 that constitute the second laser peening mark row 162. The second radius r2 is a distance shorter than the separation distance α0 described above, and is a distance defined as r2 = d2 / 2. Note that d2 used in defining the second radius r2 is the distance between the laser peening marks 15 that constitute the second laser peening mark row 162 (spot distance d2).

[0069] It is believed that such an in-plane stress distribution is also caused by the laser scribing process. That is, at the close position NP2, the formation of the laser peening mark 15 compresses the surrounding soft magnetic alloy, resulting in compressive stress. On the other hand, at the intermediate position MP, as described above, this compressive stress is relatively small because it is far from the laser peening mark 15. It is believed that by optimizing the in-plane stress distribution in this way, the energy required for magnetization is reduced, and the iron loss of the soft magnetic alloy ribbon 1 can be reduced.

[0070] As described above, the proximity position NP2 is a position on the circumference of the second reference circle DC2, and is not limited to a single point. In Fig. 4, as an example, the intersection of the second reference circle DC2 and the reference line DL is referred to as the "proximity position NP2a," and the intersection of the second reference circle DC2 and the second laser peening mark row 162 is referred to as the "proximity position NP2b." The in-plane stress σ2 at the proximity position NP2a is particularly referred to as the "in-plane stress σ2a," and the in-plane stress σ2 at the proximity position NP2b is particularly referred to as the "in-plane stress σ2b."

[0071] In this case, the relationships σ0<σ2a and σ0<σ2b are established. Note that the in-plane stress σ2a and the in-plane stress σ2b may be equal to or different from each other.

[0072] As described above, the soft magnetic alloy ribbon 1 according to this embodiment is a ribbon made of an Fe-based soft magnetic alloy, and has the first laser peening mark row 161 and the second laser peening mark row 162. The first laser peening mark row 161 and the second laser peening mark row 162 are made up of a plurality of laser peening marks 15 arranged in rows in the first direction α, and are lined up adjacent to each other in the second direction β intersecting the first direction α.

[0073] Also, a straight line that is at an equal separation distance α0 from the first laser peening mark row 161 and the second laser peening mark row 162 is defined as a middle line CL. Furthermore, a circle that is located around the center of the laser peening marks 15 that constitute the first laser peening mark row 161 and has a first radius r1 that is shorter than the separation distance α0 is defined as a first reference circle DC1. Also, a straight line that passes through the center of the laser peening mark 15 and is parallel to the second direction β is defined as a reference line DL.

[0074] When the in-plane stress at the intersection (intermediate position MP) of the reference line DL and the intermediate line CL is σ0 and the in-plane stress on the circumference of the first reference circle DC1 is σ1, the soft magnetic alloy ribbon 1 according to this embodiment satisfies the relationship σ0<σ1.

[0075] By satisfying this relationship, the distribution of in-plane stress is optimized in the soft magnetic alloy ribbon 1. In other words, although the distribution of in-plane stress changes due to the laser scribing process, when the distribution of in-plane stress satisfies the relationship σ0<σ1, the domain wall 2 is easily moved by an external magnetic field. This reduces the energy required for AC magnetization, and the iron loss of the soft magnetic alloy ribbon 1 can be reduced.

[0076] As described above, the circle that is located around the center of the laser peening marks 15 that constitute the second laser peening mark row 162 and has a second radius r2 that is shorter than the separation distance α0 is defined as the second reference circle DC2. When the in-plane stress on the circumference of the second reference circle DC2 is defined as σ2, the soft magnetic alloy ribbon 1 according to this embodiment satisfies the relationship σ0<σ2.

[0077] By satisfying such a relationship, the distribution of in-plane stress is further optimized in the soft magnetic alloy ribbon 1. That is, in this embodiment, the distribution of in-plane stress satisfies the relationship σ0<σ2, so that the domain wall 2 is easily moved by an external magnetic field. This further reduces the energy required for AC magnetization, and the iron loss of the soft magnetic alloy ribbon 1 can be further reduced.

[0078] The soft magnetic alloy ribbon 1 does not necessarily have to satisfy the relationship σ0<σ2, but it is preferable that it does so from the viewpoint of reducing the iron loss of the entire soft magnetic alloy ribbon 1.

[0079] Furthermore, the above-described relationship σ0<σ1 and the relationship σ0<σ2 do not need to be satisfied over the entire soft magnetic alloy ribbon 1, but may be satisfied over at least a portion of the soft magnetic alloy ribbon 1. Specifically, these relationships are preferably satisfied over an area ratio of 30% or more, and more preferably over an area ratio of 50% or more.

[0080] As described above, the direction in which the laser peening mark rows 16 are arranged is the second direction β, and the direction in which the domain walls 2 extend is the third direction γ. In this embodiment, the second direction β and the third direction γ are parallel to each other.

[0081] As a result, for example, when the laser peening mark rows 16 are arranged along the length direction Y of the soft magnetic alloy ribbon 1, the domain walls 2 also extend along the length direction Y. In this case, the axis of easy magnetization of the soft magnetic alloy ribbon 1 is the same as the length direction Y, and therefore, when a magnetic core is produced by winding the soft magnetic alloy ribbon 1, the axis of easy magnetization is the same as the circumferential direction of the magnetic core. As a result, for example, a soft magnetic alloy ribbon 1 suitable for a wound core or the like can be obtained.

[0082] The in-plane stresses σ0, σ1, and σ2 each vary depending on the composition of the soft magnetic alloy, but as an example, σ0 is preferably 50 MPa to 1000 MPa, more preferably 100 MPa to 800 MPa, and even more preferably 100 MPa to 700 MPa, which makes it particularly easy for the domain wall 2 to move in response to an external magnetic field.

[0083] The ratios of σ1 / σ0 and σ2 / σ0 are each greater than 1, preferably greater than 2, and more preferably greater than or equal to 2 and less than or equal to 5. This makes it possible to particularly reduce the iron loss of the soft magnetic alloy ribbon 1. The in-plane stresses σ1 and σ2 may be the same as or different from each other.

[0084] The in-plane stresses σ0, σ1, and σ2 can be measured by, for example, irradiating a material with radiation such as X-rays and analyzing the state of scattered X-rays, by using acoustoelasticity, by temperature distribution, or by using Raman scattered light.

[0085] The in-plane stresses σ0, σ1, and σ2 can also be determined by numerical analysis using finite element method analysis software. Examples of finite element method analysis software include ANSYS (registered trademark) and COMSOL (registered trademark). In these finite element method analyses, the von Mises stress at each point on the soft magnetic alloy ribbon 1 can be calculated by inputting initial conditions such as the composition of the soft magnetic alloy, the line spacing d1, the spot spacing d2, the spot diameter d3, and the spot depth d4.

[0086] Furthermore, as described above, the interval between the first laser peening mark row 161 and the second laser peening mark row 162, i.e., the line interval d1, is preferably 1 mm or more and 40 mm or less. When the line interval d1 is within the above range, the arrangement density of the laser peening mark row 16 in the soft magnetic alloy ribbon 1 can be optimized. As a result, the magnetic domains 3 can be favorably subdivided, and the iron loss of the soft magnetic alloy ribbon 1 can be further reduced.

[0087] Furthermore, as described above, the interval between the laser peening marks 15 in the laser peening mark row 16 including the first laser peening mark row 161 and the second laser peening mark row 162, i.e., the spot interval d2, is preferably 1.0 mm or less. When the spot interval d2 is within the above range, the arrangement density of the laser peening marks 15 in the laser peening mark row 16 can be optimized. As a result, the magnetic domains 3 can be favorably subdivided, and the iron loss of the soft magnetic alloy ribbon 1 can be further reduced.

[0088] 1.3.Iron Loss As described above, the soft magnetic alloy ribbon 1 according to this embodiment is designed to reduce iron loss.

[0089] Specifically, the iron loss of the soft magnetic alloy ribbon 1 under the conditions of a frequency of 50 Hz and a magnetic flux density of 1.2 T is preferably 0.05 W / kg or less, more preferably 0.04 W / kg or less, and even more preferably 0.02 W / kg or less.

[0090] Such a soft magnetic alloy ribbon 1 with low iron loss contributes to improving the efficiency of a transformer when used in, for example, a transformer. Also, when used in, for example, a motor core, it contributes to improving the conversion efficiency. Note that iron loss is measured by, for example, sinusoidal excitation using an AC magnetic measuring instrument.

[0091] 1.4. Variations Next, soft magnetic alloy ribbons according to modified examples will be described. FIG. 5 is an enlarged plan view of the first surface 11 of the soft magnetic alloy ribbon 1A according to the first modification, and is a diagram schematically showing the magnetic domains 3 and the magnetic domain walls 2 of the soft magnetic alloy ribbon 1A.

[0092] The soft magnetic alloy ribbon 1A shown in FIG. 5 is similar to the soft magnetic alloy ribbon 1 shown in FIG. 4 except that the positions of the laser peening marks 15 constituting the second laser peening mark row 162 in the width direction X are shifted from the domain walls 2.

[0093] As mentioned above, the domain wall 2 is formed regardless of the position of the laser peening marks 15, and therefore, as shown in FIG. 5, the domain wall 2 may intersect with the second laser peening mark row 162 at a position where the laser peening marks 15 are not present.

[0094] FIG. 6 is an enlarged plan view of the first surface 11 of the soft magnetic alloy ribbon 1B according to the second modification, and is a diagram schematically showing the magnetic domains 3 and the domain walls 2 of the soft magnetic alloy ribbon 1B.

[0095] The soft magnetic alloy ribbon 1B shown in FIG. 6 is similar to the soft magnetic alloy ribbon 1A shown in FIG. 5 except that the positions of the laser peening marks 15 constituting the first laser peening mark row 161 in the width direction X are shifted from the domain walls 2.

[0096] As shown in FIG. 6, the domain wall 2 may intersect with the first laser peening mark row 161 at a position where the laser peening mark 15 does not exist. In the above-described modified example, the same effects as those of the above-described embodiment can be obtained.

[0097] 2. Manufacturing method of soft magnetic alloy ribbon Next, an example of a method for producing a soft magnetic alloy ribbon will be described. FIG. 7 is a flowchart illustrating an example of a method for manufacturing a soft magnetic alloy ribbon.

[0098] The manufacturing method of the soft magnetic alloy ribbon shown in FIG. 7 includes a material preparation step S102 and a laser processing step S104. In the material preparation step S102, a material ribbon made of a soft magnetic alloy is prepared. In the laser processing step S104, laser processing is performed on one main surface of the material ribbon. As a result, a laser peening mark row consisting of a plurality of laser peening marks arranged in a row is formed. Thereafter, if necessary, a heat treatment is performed in a magnetic field. As a result, a soft magnetic alloy ribbon is obtained.

[0099] 2.1.Material preparation process The material ribbon is produced by a method for producing a rapidly solidified ribbon, such as a single roll method. The material preparing step S102 may be a step of producing a material ribbon by such a production method, may include a step of cutting the material ribbon produced by the above-mentioned production method to a required length, or may be a step of simply preparing a material ribbon.

[0100] 2.2.Laser processing process In the laser processing step S104, laser processing is performed on at least one main surface of the material ribbon to form laser peening marks. The arrangement of the laser peening marks is the same as the arrangement of the laser peening marks 15 in the soft magnetic alloy ribbon 1 described above.

[0101] The conditions for laser processing vary depending on the alloy composition of the material ribbon, but as an example, the laser output in laser processing is preferably 0.4 mJ or more and 2.5 mJ or less, and more preferably 1.0 mJ or more and 2.0 mJ or less.

[0102] The diameter of the laser beam in laser processing determines the spot diameter d3 described above. As an example, the diameter of the laser beam is preferably 0.010 mm or more and 0.30 mm or less, and more preferably 0.020 mm or more and 0.25 mm or less.

[0103] The energy density of the laser in laser processing influences the above-mentioned spot diameter d3 and the spot depth d4 of the laser peening mark 15. As an example, the energy density of the laser is preferably 0.01 J / mm 2 More than 1.50J / mm 2 It is preferably 0.03 J / mm or less. 2 More than 1.00J / mm 2 The following is said to be true.

[0104] The wavelength of the laser in the laser processing is, for example, 250 nm or more and 1100 nm or less, and preferably 900 nm or more and 1100 nm or less.

[0105] Examples of laser light sources used in laser processing include YAG lasers, CO2 gas lasers, semiconductor lasers, and fiber lasers. Among these, fiber lasers are preferred because they can emit high-power, high-frequency pulsed laser light. The pulse width of the pulsed laser light is preferably 50 nanoseconds or more, and more preferably 100 nanoseconds or more. The pulse width is the time during which the laser is irradiated, and the smaller the pulse width, the shorter the irradiation time. By setting the pulse width within the above range, laser peening marks 15 of appropriate size and depth can be efficiently formed.

[0106] The in-plane stresses σ0, σ1, and σ2 can be adjusted by, for example, the energy density (power) of the laser, the pulse width of the pulsed laser light, the temperature and cooling rate of the rapidly solidified ribbon, the line interval d1, etc. Specifically, the compressive stress around the laser peening mark 15 can be increased by increasing the energy density of the laser or widening the pulse width. This increases the in-plane stresses σ1 and σ2. Furthermore, the in-plane stresses σ0, σ1, and σ2 can also be increased by increasing the temperature of the rapidly solidified ribbon or the cooling rate. On the other hand, the in-plane stress σ0 can be reduced by widening the line interval d1.

[0107] 3.Magnetic core Next, the magnetic core according to the embodiment will be described. FIG. 8 is a schematic diagram showing a magnetic core according to the embodiment.

[0108] The magnetic core 10 shown in Fig. 8 is configured with a laminate 17 in which a plurality of soft magnetic alloy ribbons 1 are stacked. Specifically, the laminate 17 is curved and both ends are overlap-wound to form the annular magnetic core 10 shown in Fig. 8. A known method is used for the overlap-wound method. The shape of the magnetic core 10 is not limited to the shape shown in FIG. 8, and may be any shape.

[0109] Moreover, it is preferable that the soft magnetic alloy ribbons 1 provided in the laminate 17 are insulated from each other. For example, a resin coating can be used for the insulation.

[0110] As described above, the magnetic core 10 includes the soft magnetic alloy ribbon 1 described above. This makes it possible to obtain a magnetic core 10 with low iron loss. Such a magnetic core 10 is suitable for use in, for example, a power distribution transformer, a high-frequency transformer, a saturable reactor, a magnetic switch, a choke coil, an electric motor, a generator, etc.

[0111] While the soft magnetic alloy ribbon and magnetic core of the present invention have been described above based on preferred embodiments, the present invention is not limited thereto. For example, the soft magnetic alloy ribbon and magnetic core of the present invention may be obtained by adding any component to the above-described embodiments. [Example]

[0112] Next, specific examples of the present invention will be described. 4. Manufacturing of soft magnetic alloy ribbons 4.1. Sample No. 1 First, Fe was melted by the single roll method. 82 Si4B 14 A thin material ribbon was produced, which was made of a soft magnetic alloy having the alloy composition Fe, and had a thickness of 25 μm and a width of 210 mm. 82 Si4B 14 means an alloy composition in which the Fe content is 82 atomic %, the Si content is 4 atomic %, and the B content is 14 atomic %, when the total content of Fe, Si, and B is 100 atomic %.

[0113] Next, a sample piece measuring 120 mm in length and 25 mm in width was cut out from the produced material ribbon.

[0114] Next, one main surface of the cut-out sample piece was subjected to a laser scribe process to form laser peening marks. A row of laser peening marks composed of laser peening marks was formed across the entire width direction of the material ribbon, as shown in Figure 1. In this way, a soft magnetic alloy ribbon of Sample No. 1 was obtained, in which an in-plane stress distribution was formed.

[0115] Next, a magnetic field of 1.6 kA / m was applied to the soft magnetic alloy ribbon in the length direction, and the ribbon was subjected to heat treatment at 340° C. for 1 hour.

[0116] When the heat-treated soft magnetic alloy ribbon was observed by electron holography using a transmission electron microscope, magnetic domains and domain walls as shown in FIG. 4 were observed.

[0117] Next, the in-plane stresses σ0, σ1a, and σ2a were calculated by numerical analysis using finite element analysis software. The calculation results are shown in Table 1.

[0118] 4.2. Samples No. 2 to 23 Soft magnetic alloy ribbons of each sample No. were obtained in the same manner as in the soft magnetic alloy ribbon of sample No. 1, except that the processing conditions of the laser scribing process were changed so that the in-plane stresses σ0, σ1a, and σ2a would have the values ​​shown in Table 1.

[0119] 4.3. Samples No. 24-27 Soft magnetic alloy ribbons of each sample No. were obtained in the same manner as in the soft magnetic alloy ribbon of sample No. 1, except that the processing conditions of the laser scribing process were changed so that the in-plane stresses σ0, σ1a, and σ2a would have the values ​​shown in Table 2. The in-plane stresses σ1a and σ2a were set to be different from each other.

[0120] 4.4. Samples No. 28 to 44 Soft magnetic alloy ribbons of each sample No. were obtained in the same manner as in the soft magnetic alloy ribbon of sample No. 1, except that the processing conditions of the laser scribing process were changed so that the in-plane stresses σ0 and σ1b would have the values ​​shown in Table 3.

[0121] In Tables 1 to 3, soft magnetic alloy ribbons corresponding to the present invention are designated as "Examples," and soft magnetic alloy ribbons not corresponding to the present invention are designated as "Comparative Examples."

[0122] 5. Evaluation of soft magnetic alloy ribbons For the soft magnetic alloy ribbons of each example and each comparative example, iron loss was measured under conditions of a frequency of 50 Hz and a magnetic flux density of 1.2 T. The measurement results were evaluated in accordance with the following evaluation criteria.

[0123] A: Iron loss is 0.02W / kg or less B: Iron loss is greater than 0.02 W / kg and less than or equal to 0.05 W / kg C: Iron loss is over 0.05W / kg The evaluation results are shown in Tables 1 to 3.

[0124] [Table 1]

[0125] [Table 2]

[0126] [Table 3]

[0127] As is clear from Tables 1 to 3, the soft magnetic alloy ribbons of the examples had lower iron loss than the soft magnetic alloy ribbons of the comparative examples. Therefore, it was found that the present invention can realize a soft magnetic alloy ribbon that can be used to manufacture a magnetic core with low iron loss.

[0128] Here, the in-plane stresses σ0 and σ1a shown in Table 1 were plotted on an orthogonal coordinate system to create a graph. FIG. 9 is a graph created by plotting data on the in-plane stresses σ0 and σ1a of the soft magnetic alloy ribbons of each sample number shown in Table 1 on an orthogonal coordinate system with the in-plane stress σ1a on the horizontal axis and the in-plane stress σ0 on the vertical axis. Note that in the graph of FIG. 9, the type of plot mark is changed based on the above evaluation results. Also, in FIG. 9, auxiliary lines are drawn at the position where the ratio of the in-plane stresses σ1a / σ0 is 1 and at the position where the ratio of the in-plane stresses σ1a / σ0 is 2, respectively.

[0129] In Figure 9, if the in-plane stress ratio σ1a / σ0 is greater than 1, the iron loss evaluation result is B or higher, and if it is 2 or higher, the iron loss evaluation result is A. From these results, it was confirmed that by optimizing the in-plane stress ratio σ1a / σ0, it is possible to further reduce iron loss. The same is also thought to be true for the in-plane stress ratio σ2a / σ0.

[0130] Further, the in-plane stresses σ0 and σ1b shown in Table 3 were plotted on an orthogonal coordinate system to create a graph. FIG. 10 is a graph created by plotting data on the in-plane stresses σ0 and σ1b of the soft magnetic alloy ribbons of each sample number shown in Table 3 on an orthogonal coordinate system with the in-plane stress σ1b on the horizontal axis and the in-plane stress σ0 on the vertical axis. Note that in the graph of FIG. 10, the type of plot mark is changed based on the above evaluation results. Also, in FIG. 10, auxiliary lines are drawn at the position where the ratio of the in-plane stresses σ1b / σ0 is 1 and at the position where the ratio of the in-plane stresses σ1b / σ0 is 2, respectively.

[0131] In Figure 10, if the in-plane stress ratio σ1b / σ0 exceeds 1, the iron loss evaluation result is B or higher, and if it is 2 or higher, the iron loss evaluation result is A. From these results, it was confirmed that further reduction in iron loss is possible by optimizing the in-plane stress ratio σ1b / σ0. [Explanation of symbols]

[0132] 1...soft magnetic alloy ribbon, 1A...soft magnetic alloy ribbon, 1B...soft magnetic alloy ribbon, 2...domain wall, 3...magnetic domain, 10...magnetic core, 11...first surface, 12...second surface, 15...laser peening mark, 16...laser peening mark row, 17...laminated body, 161...first laser peening mark row, 162...second laser peening mark row, CL...midline, DC1...first reference circle, DC2...second reference circle, DL...reference line, MP...midline position, NP1...proximal position, NP1 a...proximity position, NP1b...proximity position, NP2...proximity position, NP2a...proximity position, NP2b...proximity position, S102...material preparation process, S104...laser processing process, L...length, W...width, X...width direction, Y...length direction, Z...thickness direction, d1...line spacing, d2...spot spacing, d3...spot diameter, d4...spot depth, r1...first radius, r2...second radius, t...thickness, α...first direction, α0...separation distance, β...second direction, γ...third direction

Claims

1. A thin ribbon made of an Fe-based soft magnetic alloy, the laser peening mark is formed of a plurality of laser peening marks arranged in a row in a first direction, and has a first laser peening mark row and a second laser peening mark row arranged adjacent to each other in a second direction intersecting the first direction, The width is 5 mm or more and 500 mm or less, The thickness is 1 μm or more and 40 μm or less, the Fe-based soft magnetic alloy is an Fe—Si—B alloy or an Fe—Si—B—C alloy, The Fe-based soft magnetic alloy contains at least one of an amorphous structure and a nanocrystalline structure in a total amount of 50% by volume or more, a straight line that is equally spaced from the first laser peening mark row and the second laser peening mark row is defined as an intermediate line; a first reference circle is a circle that is positioned around a center of the laser peening marks that constitute the first laser peening mark row and has a first radius that is shorter than the separation distance; a circle that is positioned around a center of the laser peening marks that constitute the second laser peening mark row and has a second radius that is shorter than the separation distance is defined as a second reference circle; a straight line that passes through a center of the laser peening marks that constitute the first laser peening mark row and a center of the laser peening marks that constitute the second laser peening mark row and is parallel to the second direction is set as a reference line; The in-plane stress at the intersection of the reference line and the intermediate line is σ0, The in-plane stress on the circumference of the first reference circle is defined as σ1, When the in-plane stress on the circumference of the second reference circle is σ2, The relationship of σ0<σ1 and the relationship of σ0<σ2 are satisfied, The ratio of σ1 / σ0 and the ratio of σ2 / σ0 are each greater than 1 and equal to or less than 5; The in-plane stress σ0, the in-plane stress σ1, and the in-plane stress σ2 are each 50 MPa or more and 1000 MPa or less, an interval between the first laser peening mark row and the second laser peening mark row is 1 mm or more and 40 mm or less; The spot spacing between the laser peening marks is 1.0 mm or less, The spot diameter of the laser peening mark is 0.010 mm or more and 0.30 mm or less, The soft magnetic alloy ribbon is characterized in that the spot depth of the laser peening mark is 0.0020 mm or more and 0.15 mm or less.

2. 2. The soft magnetic alloy ribbon according to claim 1, wherein an iron loss at a frequency of 50 Hz and a magnetic flux density of 1.2 T is 0.05 W / kg or less.

3. A method for producing the soft magnetic alloy ribbon according to claim 1 or 2, comprising: preparing a material ribbon made of a soft magnetic alloy; forming the laser peening marks on the material ribbon by performing laser processing on the material ribbon with a pulsed laser beam; and the energy density of the pulsed laser beam is 0.01 J / mm 2 or more and 1.50 J / mm 2 or less; the pulse width of the pulsed laser light is 50 nanoseconds or more; the diameter of the pulsed laser beam is 0.010 mm or more and 0.30 mm or less; adjusting the in-plane stress σ1 and the in-plane stress σ2 based on the energy density of the pulsed laser beam or the pulse width of the pulsed laser beam; a method for producing a soft magnetic alloy ribbon, characterized in that the in-plane stress σ0 is adjusted based on an interval between the first laser peening mark row and the second laser peening mark row.

4. A magnetic core comprising the soft magnetic alloy ribbon according to claim 1 or 2.

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