Alloy composition, iron-based nanocrystalline soft magnetic alloy and preparation method and application of iron-based nanocrystalline soft magnetic alloy

Abstract

The invention belongs to the technical field of magnetic functional materials, and particularly relates to an alloy composition, an iron-based nanocrystalline soft magnetic alloy, a preparation method and application. Compared with the prior art, the novel iron-based nanocrystalline soft magnetic alloy researched and developed through a rapid heat treatment technology of 100 DEG C / s or above has better amorphous forming ability in terms of alloy component selection, the difficulty of amorphous strip preparation is reduced, and the maximum amorphous critical thickness can reach 25 microns or above. The upper limit of the saturation flux density of the nanocrystalline alloy is reduced, but the saturation flux density of the nanocrystalline alloy is still kept at a high level (1.75-1.82 T). The distance between a first crystallization temperature and a second crystallization temperature of an alloy amorphous precursor is shortened due to consideration of amorphous forming ability and saturation magnetic induction, so that the control difficulty of nanocrystallization is increased, and therefore, the control difficulty of nanocrystallization is increased by matching mechanical energy injection pretreatment with continuous high-heating-rate heat treatment on the amorphous precursor; the coercive force of the alloy after nanocrystallization is lower than 10 A / m, and the ferromagnetic loss (1 kHz 1.5 T) is lower than 160 mW / cm < 3 >.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic functional materials, and in particular relates to an alloy composition, an iron-based nanocrystalline soft magnetic alloy, and a preparation method and application thereof. Background Art

[0002] High-saturation magnetic induction nanocrystalline materials have significant application value in the power and electronics fields due to their high energy density, fast response speed, and low loss. In practical applications, the saturation magnetic induction of soft magnetic materials significantly affects the size of devices, and high saturation magnetic induction is a key indicator for device miniaturization. The soft magnetic properties of soft magnetic materials are a prerequisite for ensuring device energy efficiency and operating frequency. It is crucial for soft magnetic materials to possess both high saturation magnetic induction and excellent soft magnetic properties.

[0003] However, high-saturation magnetic nanocrystalline materials generally have high iron contents (over 80 at%) and low pre-transition metal contents (less than 2 at%), resulting in poor amorphous-forming ability. This results in poor stability of the quenched amorphous precursor and difficulty maintaining soft magnetic properties after heat treatment. Increasing the boron content in high-iron nanocrystalline alloys can improve the alloy's amorphous-forming ability, but this also causes the primary and secondary crystallization processes of the amorphous precursor to partially overlap, resulting in failure to achieve the desired improvement in the nanocrystalline's soft magnetic properties.

[0004] High saturation magnetic induction iron-based nanocrystalline soft magnetic alloys are usually obtained by nanocrystallizing amorphous strips prepared by melt rapid quenching technology. The alloy composition usually needs to meet the following conditions: 1. The alloy composition needs to have sufficiently excellent amorphous glass-forming ability to be able to produce uniform and continuous amorphous strips with dimensions and quality that meet subsequent processing requirements through melt rapid quenching technology; 2. The alloy composition needs to be able to form a bcc-Fe and amorphous composite phase during subsequent nanocrystallization; 3. The alloy composition needs to have a sufficient refining effect on the nanocrystalline structure to ensure the soft magnetic properties of the nanocrystalline alloy; 4. On the premise of meeting 1-3, try to meet the requirements of alloy composition for saturation magnetic induction.

[0005] There is a conflict between the above conditions. Since the preparation requirements and soft magnetic properties must be compromised, the improvement of the saturation magnetic induction of iron-based nanocrystalline alloys is significantly restricted.

[0006] Currently, a high heating rate heat treatment process is essential for achieving high saturation magnetic induction of iron-based nanocrystalline soft magnetic alloys exceeding 1.75 T. The differences in alloy performance and application feasibility stem from the alloy's compositional design. Chinese patent CN102741437B provides a chemical composition for an iron-based nanocrystalline soft magnetic alloy. Its compositional design is based on a 100°C / min heat treatment process, ensuring its saturation magnetic induction. However, soft magnetic properties such as coercivity are relatively poor, reaching a maximum of 100 A / m. Furthermore, this alloy ensures amorphous formation by adding sufficient phosphorus (P). However, compared to Si and B, which are also non-metallic elements, P is more difficult to purify, making the raw material Fe-P more significantly affected by its purity. Furthermore, Chinese patent CN109844873A provides a soft magnetic material and manufacturing method that combines high saturation magnetization with low coercivity. The alloy's composition is designed based on a higher heating rate, resulting in improved soft magnetic properties. Because the alloy contains no Si, the upper limit of the saturation magnetic induction intensity that can be achieved is higher. However, the soft magnetic properties of this alloy composition are very sensitive to the quality of the amorphous precursor and the heat treatment parameters. High-quality strip (approximately 10-14 μm thick) and precise control of the strip temperature and time during the heat treatment are required to achieve the desired soft magnetic properties. To achieve optimal soft magnetic properties, the temperature control accuracy during the heat treatment process typically needs to be within 20°C, and the heat treatment process must be shorter than 20 seconds, which increases the difficulty of material manufacturing. Summary of the Invention

[0007] The purpose of the present invention is to provide an alloy composition, an iron-based nanocrystalline soft magnetic alloy, a preparation method and an application thereof, so as to solve the technical problem.

[0008] The first aspect of the present application provides an alloy composition having a composition formula of Fe a B b Ni c Cu d ;in a+b+c+d=100at%; and a = 79~82 at%, b = 16~18 at%, c = 1~2 at%, d = 0.8~1.3 at%.

[0009] In one embodiment of the present application, 1:1 ≤ c:d ≤ 2:1.

[0010] In one embodiment of the present application, when a ≤ 81.5, d ≥ 1; when a ≤ 80.5, d ≥ 1.2.

[0011] The second aspect of the present application provides a method for preparing an iron-based nanocrystalline soft magnetic alloy, comprising: preparing the alloy composition as described above to prepare a completely amorphous amorphous precursor strip; and heat treating the strip to obtain an iron-based nanocrystalline soft magnetic alloy.

[0012] In one embodiment of the present application, a method for preparing an alloy composition includes: manufacturing a master alloy ingot by vacuum melting; The method for preparing a completely amorphous amorphous precursor ribbon comprises: preparing a completely amorphous amorphous precursor ribbon with a thickness of 20-30 μm by a planar flow casting method.

[0013] In one embodiment of the present application, the difference between the first crystallization temperature and the second crystallization temperature of the amorphous precursor ribbon is 70-100° C. as measured by DSC at a heating rate of 40° C. / min.

[0014] In one embodiment of the present application, the preparation method further comprises, before heat treating the strip: The strip is rolled into a coil by a winding device; Then, mechanical energy is injected through a roll-to-roll conveying device; the roll-to-roll conveying device maintains a constant tension of 1-10 MPa.

[0015] In one embodiment of the present application, the method for heat treating the strip includes: maintaining the temperature between 460° C. and 500° C. for 5 to 60 seconds; and a heating rate of 100 to 1000° C. / s.

[0016] The third aspect of the present application provides an iron-based nanocrystalline soft magnetic alloy prepared by the preparation method described above, which has a saturation magnetic induction Bs = 1.75-1.82 T, a coercive force HC = 4-10 A / m, and a ferromagnetic loss lower than 160 mW / cm 3 .

[0017] A fourth aspect of the present application provides a use of the above-mentioned iron-based nanocrystalline soft magnetic alloy in a magnetic component.

[0018] The beneficial effects of the present invention are: A new iron-based nanocrystalline soft magnetic alloy developed through rapid heat treatment at speeds exceeding 100°C / s combines improved glass-forming ability with the alloy composition selection compared to existing technologies (e.g., Chinese patent publication CN109844873A), reducing the difficulty of amorphous ribbon preparation and enabling a maximum amorphization critical thickness exceeding 25μm. This lowers the upper limit of the nanocrystalline alloy's saturation magnetic induction, while still maintaining a relatively high level (1.75-1.82 T). This balance between glass-forming ability and saturation magnetic induction reduces the distance between the first and second crystallization temperatures of the alloy's amorphous precursor, making nanocrystallization control more difficult. To address this issue, a mechanical energy injection pretreatment combined with continuous high-temperature-rate heat treatment ensures that the alloy's coercivity after nanocrystallization is below 10 A / m and its ferromagnetic loss (1 kHz 1.5 T) is below 160 mW / cm³.

[0019] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 is a schematic diagram of a roll-to-roll conveying device and a roll-to-roll heat treatment device; Figure 2 Fe 81.9 B 16.2 Ni1Cu 0.9 Amorphous precursor strip cross-section thickness measurement; Figure 3 Yes, it's Fe 81.9 B 16.2 Ni1Cu 0.9 XRD diffraction spectrum of the free surface of amorphous precursor ribbon; Figure 4 It is Fe 81.9 B 16.2 Ni1Cu 0.9DSC heat flow curve of amorphous precursor at uniform heating rate; Figure 5 It is Fe 81.9 B 16.2 Ni1Cu 0.9 Static BH curve of nanocrystalline ribbon; Figure 6 It is Fe 81.9 B 16.2 Ni1Cu 0.9 VSM curve of nanocrystalline ribbon after heat treatment at 490℃ for 30s; Figure 7 It is Fe 81.9 B 16.2 Ni1Cu 0.9 Ferromagnetic loss of nanocrystalline ribbons after heat treatment under different conditions (1.5 T); Figure 8 Fe 81 B 17 Ni1Cu1 amorphous precursor strip cross-section thickness measurement; Figure 9 It is Fe 81 B 17 XRD diffraction spectrum of the free surface of Ni1Cu1 amorphous precursor ribbon; Figure 10 It is Fe 81 B 17 DSC heat flow curve of Ni1Cu1 amorphous precursor at uniform heating rate; Figure 11 It is Fe 81 B 17 Static BH curve of Ni1Cu1 nanocrystalline ribbon; Figure 12 It is Fe 81 B 17 Ferromagnetic loss of Ni1Cu1 nanocrystalline ribbons after heat treatment under different conditions (1.5 T); Figure 13 Fe 79 B 18 Ni 1.7 Cu 1.3 Amorphous precursor strip cross-section thickness measurement; Figure 14 It is Fe 79 B 18 Ni 1.7 Cu 1.3 DSC heat flow curve of amorphous precursor at uniform heating rate; Figure 15 It is Fe 80 B 18 DSC heat flow curve of Ni1Cu1 amorphous precursor under uniform heating rate. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0024] The alloy composition of one embodiment of the present invention is suitable as a starting material alloy composition of an iron-based nanocrystalline soft magnetic alloy, and its composition formula is Fe a B b Ni c Cu d ; where a+b+c+d=100at%; and a = 79~82 at%, b = 16~18 at%, c = 1~2 at%, d = 0.8~1.3 at%.

[0025] In this embodiment, Ni and Cu are required elements, not optional elements that partially replace Fe. For iron-based nanocrystalline soft magnetic alloys, the Fe content essentially determines the alloy's saturation magnetic flux density and amorphous forming ability. Alloys with high Fe content have high saturation magnetic flux density but poor amorphous forming ability. Alloys with poor amorphous forming ability have a thin critical manufacturing thickness, low yield in industrial production, and problems such as embrittlement and band breakage. In this embodiment, a ≤ 82 at% is specified to ensure that the alloy's critical manufacturing thickness is ≥ 20 microns to meet the yield requirements in industrial production and the efficiency requirements of wound magnetic core laminations. A reduction in Fe content leads to a narrowing of the crystallization window, so the Fe content has a lower limit, and low Fe content must coexist with high Cu content to ensure the existence of a crystallization window at high heating rates. The addition of Cu can refine the nanocrystalline microstructure and widen the crystallization window. Adding Cu exceeding 1.3 at% results in poor amorphous forming ability of the alloy and a significant reduction in manufacturing thickness, so the Cu content needs to be limited to 1.3 at%. Adding a small amount of Ni can promote the nucleation of Fe nanocrystals without affecting the saturation magnetic induction, and slightly widen the crystallization window. The alloy system and heat treatment method described in this embodiment are special, and it is necessary to ensure the width of the crystallization window and the density of nucleation. Therefore, Ni is a necessary element in the alloy described in this embodiment, and it is not an optional element. The Ni element has a stabilizing effect on the FCC structure of Fe, causing the Fe-based alloy to change from the ferromagnetic characteristics of BCC to the paramagnetic characteristics of FCC. Adding Ni to 3at% and above will have a certain negative effect on the performance of the Fe-based nanocrystalline alloy, which is mainly manifested in that the soft magnetic properties are no longer improved and the saturation magnetic induction is reduced. Therefore, the content of Ni is limited to 2at% and below.

[0026] Si, a common elemental substitute for B, broadens the temperature window between the first and second crystallization temperatures and increases the maximum volume fraction of the crystalline phase. Because Si is less effective than B in enhancing the glass-forming ability of Fe-based alloys, the alloy described in this embodiment does not contain Si, other than impurities from the raw materials, to ensure the critical thickness of the alloy.

[0027] It should be noted that, preferably, 1:1 ≤ c:d ≤ 2:1; more preferably, when a ≤ 81.5, d ≥ 1; when a ≤ 80.5, d ≥ 1.2.

[0028] The alloy composition of this embodiment can be formed, for example, by vacuum melting to produce a master alloy ingot. This ingot can then be formed into a completely amorphous amorphous precursor strip with a thickness of 20-30 μm by planar flow casting. After the 20-30 μm amorphous strip is produced, the difference between the first and second crystallization temperatures is 70-100°C as measured by DSC at a heating rate of 40°C / min. After casting, the strip is coiled by a coiling device; then Figure 1 The roll-to-roll conveyor shown in a is used to inject mechanical energy. The roll-to-roll conveyor maintains a constant tension of 1-10 MPa. The tension is used to ensure that the strip passes through the intermediate metal blade in a taut state during conveyance. The metal blade scrapes the tensioned strip to inject mechanical energy. The processed strip is Figure 1 The roll-to-roll heat treatment apparatus shown in center b undergoes heat treatment (heating rate 100-1000°C / s), maintaining the temperature between 460-500°C for 5-60 s, to produce an iron-based nanocrystalline soft magnetic alloy. The resulting iron-based nanocrystalline soft magnetic alloy exhibits the following performance indicators: saturation magnetic induction (measured in an 800 kA / m magnetic field) Bs = 1.75-1.82 T; coercivity Hc = 4-10 A / m; and ferromagnetic loss (1 kHz, 1.5 T) less than 160 mW / cm 3 The roll-to-roll heat treatment device unwinds on one side and rewinds on the other side, and undergoes heat treatment through a heating device in the middle.

[0029] In this embodiment, the first crystallization temperature and the second crystallization temperature are the temperatures indicated by the peak values ​​of the crystallization heat flow of the amorphous material measured by DSC at a heating rate of 40°C / min. The purpose of a high heating rate of more than 100°C / s during the heat treatment process is to raise the crystallization temperature of the nanocrystalline material, suppress the nucleation behavior of the material at low temperatures, and ensure that the microstructure is refined. The high heating rate has a greater effect on raising the first crystallization temperature than on the second crystallization temperature, resulting in a narrowing or even disappearance of the crystallization window, making it impossible to achieve material performance. It is necessary to balance the relative contents of Fe, Ni and Cu as described in this embodiment to ensure that the window between the first crystallization temperature and the second crystallization temperature measured at a heating rate of 40°C / min exceeds 70°C, thereby ensuring the existence of a crystallization window at a high heating rate. The purpose of the mechanical energy injection process before the high heating rate heat treatment described in this embodiment is to increase the energy of the amorphous state, increase the energy change required for relaxation in the "relaxation-nucleation-growth" process, reduce the genetic effect of nucleation on the subsequent microstructure during the heating process, and achieve the improvement of nanocrystal performance and the expansion of the crystallization time window.

[0030] The iron-based nanocrystalline soft magnetic alloy prepared in this embodiment can be applied to magnetic components, including but not limited to transformer soft magnetic cores, inductor coil cores, and motor stator cores.

[0031] Example 1: Fe was prepared by rapid quenching of the melt. 81.9 B 16.2 Ni1Cu 0.9 Amorphous ribbon, the thickness of the ribbon was measured by scanning electron microscopy to be 22-24 μm (see Figure 2 ). XRD confirmed that the ribbon is completely amorphous (see Figure 3 ). After DSC (heating rate 40 ℃ / s), it was confirmed that the difference between the first crystallization temperature and the second crystallization temperature was 86.7℃ (see Figure 4 ).

[0032] Fe 81.9 B 16.2 Ni1Cu 0.9 The amorphous ribbons were transformed into nanocrystalline ribbons through mechanical energy injection and heat treatment. The coercive force, relative magnetic permeability and saturation magnetic induction intensity data are shown in Table 1.

[0033] Table 1. Fe 81.9 B 16.2 Ni1Cu 0.9 Performance table of nanocrystalline ribbons formed from amorphous ribbons under different conditions.

[0034] Example name Annealing temperature (℃) Annealing time (s) Coercive force (A / m) Saturation magnetic induction intensity (T) Example 1 460 5 8.2 1.81 30 8.1 1.81 60 9.9 1.82 470 5 7 1.82 30 8.2 1.82 60 8.5 1.82 480 5 6.9 1.82 30 7.3 1.82 60 7.2 1.82 490 5 5.6 1.82 30 5.9 1.82 60 6.8 1.82 500 5 14.1 1.82 30 60 Figure 5 Fe 81.9 B 16.2Ni1Cu 0.9 An example of a static BH curve of a nanocrystalline ribbon formed after mechanical energy injection treatment and annealing at 490 degrees Celsius for 30 seconds. As shown in the figure, its coercivity is 5.9 A / m, B 800 About 1.70 T.

[0035] Figure 6 Fe 81.9 B 16.2 Ni1Cu 0.9 An example of a VSM data curve of a nanocrystalline alloy after annealing at 490 degrees Celsius for 30 seconds. The saturation magnetization M s The value is 192 emu / g. Combined with the nanocrystalline alloy density of 7.55 g / cm 3 The saturation magnetic induction intensity in Tesla (T) can be calculated: ; Figure 7 To measure Fe using the Epstein circle method 81.9 B 16.2 Ni1Cu 0.9 Ferromagnetic loss of nanocrystalline alloys under different operating conditions after annealing at 460-490 degrees Celsius for 5-30 seconds; as shown in the figure, the ferromagnetic loss is less than 160 mW / cm at 1.5 T 1 kHz. 3 .

[0036] Example 2: Fe was prepared by rapid quenching of the melt. 81 B 17 The thickness of Ni1Cu1 amorphous ribbon was 30-31 μm as measured by scanning electron microscopy (see Figure 8 ). XRD confirmed that the ribbon is completely amorphous (see Figure 9 ). After DSC (heating rate 40 ℃ / s), it was confirmed that the difference between the first crystallization temperature and the second crystallization temperature was 74.63℃ (see Figure 10 ).

[0037] Fe 81 B 17 The Ni1Cu1 amorphous ribbons were transformed into nanocrystalline ribbons through mechanical energy injection and heat treatment. The coercivity, relative permeability and saturation magnetic induction intensity data are shown in Table 2.

[0038] Figure 11 Fe 81 B 17 The static BH curve of the nanocrystalline ribbon formed after the Ni1Cu1 amorphous ribbon was treated by the pretreatment process described in 8 and annealed at 490 degrees Celsius for 5 seconds. As shown in the figure, its coercivity is about 5.8 A / m, B 800About 1.69 T.

[0039] Figure 12 To measure Fe using the Epstein circle method 81 B 17 Ferromagnetic loss of Ni1Cu1 nanocrystalline alloy under different working conditions after annealing at 460-490 degrees Celsius for 30 seconds. As shown in the figure, the ferromagnetic loss is less than 160mW / cm at 1.5T 1kHz. 3 .

[0040] Table 2. Fe 81 B 17 Performance table of Ni1Cu1 amorphous ribbons formed into nanocrystalline ribbons under different conditions.

[0041] Example name Annealing temperature (℃) Annealing time (s) Coercive force (A / m) Saturation magnetic induction intensity (T) Example 2 460 5 9.7 1.8 30 9.9 1.8 60 8.9 1.81 470 5 7.3 1.8 30 6.6 1.81 60 6.7 1.81 480 5 6.1 1.8 30 6.5 1.81 60 6.5 1.81 490 5 5.8 1.81 30 8.7 1.81 60 6.3 1.81 500 5 6.1 1.81 30 9.3 1.81 60 Example 3: Fe was prepared by rapid quenching of the melt. 79 B 18 Ni 1.7 Cu 1.3 Amorphous ribbon, the thickness of the ribbon was 20-21 μm as measured by scanning electron microscopy (see Figure 13 ). After DSC (heating rate 40 ℃ / s), it was confirmed that the difference between the first crystallization temperature and the second crystallization temperature was 94.2℃ (see Figure 14 ).

[0042] Fe 79 B 18 Ni 1.7 Cu 1.3 The amorphous ribbons are transformed into nanocrystalline ribbons after mechanical energy injection and heat treatment. The coercive force, relative magnetic permeability and saturation magnetic induction intensity data are shown in Table 3.

[0043] Table 3. Fe 79 B 18 Ni 1.7 Cu 1.3 Performance table of nanocrystalline ribbons formed from amorphous ribbons under different conditions.

[0044] Example Annealing temperature (℃) Annealing time (s) Coercive force (A / m) Relative magnetic permeability (1kHz 0.4 A / m) Saturation magnetic induction intensity (T) Example 3 460 5 6.9 9800 1.79 30 8.9 10100 1.79 60 8.6 10600 1.79 470 5 6.4 11200 1.79 30 6.7 12800 1.79 60 9.6 11200 1.79 480 5 5.5 13400 1.79 30 5.9 14700 1.79 60 9.3 9600 1.79 490 5 9.8 8800 1.79 30 10.2 8200 1.79 60 　 　 　 Comparison example: After rapid quenching of the melt, Fe with a thickness of 22-25 μm was prepared. 80 B 18 The element ratio of Ni1Cu1 amorphous ribbon does not meet the restriction of "when a ≤ 80.5, d ≥ 1.2". DSC (heating rate 40 ℃ / s) confirmed that the difference between its first crystallization temperature and the second crystallization temperature is 61.8℃ (see Figure 15 ), less than 70-100 ℃ range.

[0045] Fe 80 B 18 Table 4 shows the coercivity, relative permeability, and saturation magnetic induction data for Ni1Cu1 amorphous ribbons processed by mechanical energy injection and heat treatment. When the processing temperature is low and the processing time is short, the ribbon remains amorphous, and the saturation magnetic induction is low, around 1.62 T. At this stage, the material can maintain a coercivity below 10 A / m and a relative permeability exceeding 10,000. When the processing temperature is increased or the processing time is prolonged, the ribbon begins to crystallize, and the saturation magnetic induction begins to rise, reaching a maximum of over 1.7 T. However, because the alloy composition does not meet the requirement of "when a ≤ 80.5, d ≥ 1.2," the difference between the two crystallization temperatures is too small, resulting in the formation of secondary crystallization products during the primary crystallization process, which leads to a significant increase in coercivity and a significant decrease in relative permeability. For example, after processing at 460°C for 60 seconds and 470°C for 30 seconds, the saturation magnetic induction of the alloy increases to about 1.75 T, showing crystallization characteristics, but its coercive force increases to above 90 A / m.

[0046] Table 4. Fe 80 B 18 Performance table of Ni1Cu1 amorphous ribbon after processing under different conditions.

[0047] Example name Annealing temperature (℃) Annealing time (s) Coercive force (A / m) Saturation magnetic induction intensity (T) Control Example 430 5 4.5 1.62 30 9 1.63 60 23.7 1.65 440 5 4 1.62 30 14.1 1.63 60 22.8 1.65 450 5 4 1.62 30 13.9 1.62 60 35.1 1.66 460 5 5.4 1.63 30 20.6 1.66 60 146.7 1.74 470 5 6.9 1.62 30 94.5 1.75 60 　 　 In summary, the alloy composition designed in this invention possesses sufficient amorphous-forming properties to form amorphous ribbons with a thickness of 20 microns or greater. Manufacturing is relatively straightforward, and mass production is readily possible using existing wide-width ribbon mass production technology. Furthermore, the alloy composition designed in this invention can achieve a saturation magnetic induction exceeding 1.8 T, exceeding that of common amorphous and nanocrystalline soft magnetic materials currently on the market and approaching the level of silicon steel (1.75-2.03 T). Its coercivity is maintained at an extremely low level of less than 10 A / m (silicon steel typically has a coercivity of 20-100 A / m), and its ferromagnetic loss (at 1.5 T at 1 kHz) is less than 160 mW / cm³ (JNHF super silicon steel cores produced by JFE, Japan, have a ferromagnetic loss of approximately 220 mW / cm³ at 1.0 T at 1 kHz). As a nanocrystalline soft magnetic material with high soft magnetic properties, the material described in this invention has mature mass production technology, and its raw material costs are comparable to those of similar commercially available materials. Its saturation magnetic induction is 20-50% higher than that of similar commercially available materials, offering significant advantages in high power density. Compared with similar materials described in other prior arts (such as CN102741437B and CN109844873A), the material described in the present invention is comparable in power density, but has significant advantages such as low production difficulty, good soft magnetic properties, and low raw material cost.

[0048] Based on the above-mentioned ideal embodiment of the present invention, and through the above description, relevant personnel can make various changes and modifications without departing from the scope of the technical concept of the present invention. The technical scope of the present invention is not limited to the contents of the specification.

Claims

1. An alloy composition having the formula Fe a B b Ni c Cu d ;in a+b+c+d=100at%; and a = 79~82 at%, b = 16~18 at%, c = 1~2 at%, d = 0.8~1.3 at%.

2. The alloy composition according to claim 1, characterized in that 1:1 ≤ c:d ≤ 2:

1.

3. The alloy composition according to claim 2, characterized in that When a ≤ 81.5, d ≥ 1; when a ≤ 80.5, d ≥ 1.

2.

4. A method for preparing an iron-based nanocrystalline soft magnetic alloy, characterized in that: include: preparing an alloy composition according to any one of claims 1 to 3 to prepare a completely amorphous amorphous precursor strip; The strip is subjected to heat treatment to obtain an iron-based nanocrystalline soft magnetic alloy.

5. The preparation method according to claim 4, characterized in that The method of preparing the alloy composition comprises: producing a master alloy ingot by vacuum melting; The method for preparing a completely amorphous amorphous precursor ribbon comprises: preparing a completely amorphous amorphous precursor ribbon with a thickness of 20-30 μm by a planar flow casting method.

6. The preparation method according to claim 4, characterized in that The difference between the first crystallization temperature and the second crystallization temperature of the amorphous precursor strip is 70-100° C. as measured by DSC at a heating rate of 40° C. / min.

7. The preparation method according to claim 4, characterized in that The preparation method further comprises, before heat treating the strip: The strip is rolled into a coil by a winding device; Then, mechanical energy is injected through a roll-to-roll conveying device; the roll-to-roll conveying device maintains a constant tension of 1-10 MPa.

8. The preparation method according to claim 4, characterized in that The method for heat treating the strip comprises: maintaining the temperature between 460°C and 500°C for 5 to 60 seconds; and heating rate of the temperature is 100 to 1000°C / s.

9. An iron-based nanocrystalline soft magnetic alloy, characterized in that: Prepared by the preparation method according to claim 4, the saturation magnetic induction Bs = 1.75 ~ 1.82 T, the coercive force Hc = 4 ~ 10 A / m, and the ferromagnetic loss is less than 160 mW / cm 3 .

10. Use of the iron-based nanocrystalline soft magnetic alloy according to claim 9 in magnetic components.

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