A cobalt-based amorphous alloy magnetic ring with high squareness of magnetic hysteresis loop and a preparation method thereof

Abstract

This invention discloses a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness and its preparation method, relating to the field of soft magnetic materials technology. The cobalt-based amorphous alloy magnetic ring material to be prepared comprises, by mass percentage, Fe: 4.3–4.5%, Ni: 0.8–1.1%, Si: 8–8.5%, B: 2.9–3.3%, La or Gd: 0.3–0.6%, with the balance being Co and unavoidable trace impurities. The raw materials are heated to a molten state under an inert atmosphere to form an amorphous thin strip, which is then wound into a magnetic ring and placed in an annealing furnace. The ring is uniformly heated to 360 < T < 420 °C under an inert atmosphere for 90–120 minutes, held for 60–120 minutes, with a longitudinal magnetic field applied at the beginning of the holding period. After the holding period, the ring is cooled to 120 °C with the furnace, the longitudinal magnetic field is stopped, and the ring is cooled to room temperature. This invention, through optimization of material composition and process, obtains a cobalt-based amorphous alloy magnetic ring with high squareness, low coercivity, low loss, and high permeability.

Description

Technical Field

[0001] This invention relates to the field of soft magnetic materials technology, specifically to a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness and its preparation method. Background Technology

[0002] Soft magnetic materials are core foundational materials in modern industrial fields such as power electronics, information communication, and electromagnetic equipment. Their performance directly affects power conversion efficiency, signal transmission quality, and equipment miniaturization. Among numerous soft magnetic materials, amorphous alloys, due to their unique disordered atomic structure, exhibit excellent soft magnetic properties, such as high permeability, low coercivity, and low high-frequency loss, making them an important supplement and development direction to traditional crystalline soft magnetic materials (such as silicon steel, ferrite, and permalloy).

[0003] Amorphous alloys, also known as metallic glasses, are metastable solid materials with long-range disorder and short-range order, obtained through extremely rapid cooling technology. This involves cooling molten metal at a rate on the order of millions of units per second, bypassing the time window for crystal nucleation and growth, thus freezing the liquid structure. In the field of soft magnetic properties, amorphous alloys are mainly divided into several categories, including iron-based, cobalt-based, and iron-cobalt-based alloys. Iron-based amorphous alloys have the advantages of high saturation magnetic induction and low cost, and are widely used in the cores of medium and low frequency transformers; iron-cobalt-based amorphous alloys maintain high B... s At the same time, it has better magnetic permeability; while cobalt-based amorphous alloys, with their extremely high initial magnetic permeability, near-zero magnetostriction coefficient, excellent high-frequency characteristics and good temperature stability, occupy an irreplaceable position in fields such as high-precision current transformers, high-frequency switching power supplies, common-mode inductors, magnetic amplifiers, magnetic shielding and certain precision sensors with stringent requirements for magnetic performance stability.

[0004] The hysteresis loop is a core curve characterizing the properties of soft magnetic materials, and its shape directly reflects the material's technical applicability. The squareness of the hysteresis loop (usually expressed as the rectangle ratio B) is... r / B s Squareness (or on / off field ratio, etc.) is a key indicator for evaluating the performance of materials under pulsed magnetic fields or switching conditions. High squareness means that when a material is subjected to an external magnetic field, its magnetization state can rapidly and steeply reverse in the high permeability region, with the hysteresis loop approaching an ideal rectangle. This characteristic is crucial for applications requiring fast response, low driving field, and high flux change efficiency, such as magnetic amplifiers, magnetic memories, fast magnetic switches, and certain types of spike suppression inductors. High squareness materials can significantly improve the efficiency, response speed, and stability of devices.

[0005] However, fabricating cobalt-based amorphous alloy magnetic rings that simultaneously possess excellent comprehensive soft magnetic properties (such as high permeability and low loss) and high hysteresis loop squareness faces many challenges, mainly due to the complex relationship between material composition design, fabrication process, and microstructure control: 1) The Challenge of Balancing Composition Design: The soft magnetic properties of cobalt-based amorphous alloys are highly sensitive to their composition. Typically, a significant amount of metalloid elements (such as B, Si, C, and P) needs to be added to enhance amorphous formation and ensure a fully amorphous structure at a limited cooling rate. Simultaneously, elements such as iron and nickel need to be introduced to adjust saturation magnetization, and metals such as molybdenum, niobium, and tantalum need to be added to improve thermal stability and crystallization temperature, suppressing undesirable structural relaxation or crystallization during subsequent heat treatment or service. However, improper addition and proportioning of these elements can cause pinning effects on the movement of magnetic domain walls, leading to increased coercivity, decreased permeability, and even disrupting the rectangularity of the hysteresis loop. For example, the segregation of certain elements or inhomogeneous micro-region structures may create local anisotropy, making the magnetization reversal process inconsistent.

[0006] 2) Direct Influence of Fabrication Process on Structure and Performance: Cobalt-based amorphous alloy magnetic rings are typically fabricated using a melt quenching method (such as single-roll spin quenching) to produce amorphous thin strips, which are then wound and heat-treated to form magnetic rings. During this process: Cooling rate and uniformity: The cooling rate and uniformity during rapid quenching of the melt determine the structural uniformity, internal stress distribution, and surface condition of the amorphous ribbon. Uneven cooling may introduce micro-stress fluctuations or structural undulations, which will hinder the movement of magnetic domain walls, degrade soft magnetic properties, and may cause the hysteresis loop to "collapse" or tilt, reducing squareness.

[0007] Precise control of heat treatment process: Annealing is an essential and crucial step for amorphous magnetic rings to eliminate internal stress generated during rapid quenching, optimize magnetic domain structure, and thus obtain optimal soft magnetic properties. The heat treatment temperature, time, heating / cooling rate, and the intensity and direction of the applied magnetic field (magnetic field annealing) all have a decisive impact on the final performance. Inappropriate heat treatment may lead to: excessive structural relaxation, which, while potentially reducing some stress, may introduce short-range order that is detrimental to magnetization; partial or surface crystallization, forming nanocrystalline or even microcrystalline phases, whose magnetic property differences with the amorphous matrix can severely interfere with the magnetization process; and improperly controlled magnetic field annealing, which may fail to effectively induce uniform uniaxial anisotropy, instead complicating the magnetic domain structure and preventing the acquisition of high and steep rectangular loops.

[0008] The invention patent with publication number CN110400670A, entitled "High Rectangular Ratio Cobalt-Based Amorphous Alloy Core and its Preparation Method," discloses an atomic mass percentage composition of Fe: 2-4%, Mn: 1-2%, Mo: 2-4%, Si: 10-13%, B: 11-13%, W: 0-0.5%, with Co as the balance. W is Tb, La, or a mixture of both. The method involves batching, steelmaking to prepare a master alloy, secondary remelting, and then using a single-roll melt rapid cooling method to prepare a cobalt-based amorphous alloy core. A high rectangular ratio cobalt-based amorphous alloy core is obtained through preheating treatment and high-temperature sintering. Although the method describes a rectangular ratio greater than 0.9 for the obtained cobalt-based amorphous alloy core, the actual example only reaches 0.95, leaving considerable room for improvement. Furthermore, Mn in the raw materials is easily volatilized during smelting, making its content difficult to control, and the high mass percentage of B results in high raw material costs.

[0009] In summary, developing a method for preparing cobalt-based amorphous alloy magnetic rings with reasonable composition design, strong amorphous forming ability, and controllable and efficient preparation process, which can stably obtain high maximum permeability, low high-frequency loss, and high hysteresis loop squareness, is of great theoretical significance and practical application value for meeting the urgent needs of high-end power electronic devices and precision electromagnetic measurement equipment for high-performance soft magnetic components and promoting technological progress in related industries. Summary of the Invention

[0010] The purpose of this invention is to provide a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness and its preparation method, so as to solve the problems mentioned in the background art.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness, comprising the following: The cobalt-based amorphous alloy magnetic ring material to be prepared, by mass percentage, includes Fe: 4.3–4.5%, Ni: 0.8–1.1%, Si: 8–8.5%, B: 2.9–3.3%, W: 0.3–0.6%, with the balance being Co and unavoidable trace impurities, wherein W is La or Gd; the raw materials are weighed according to the atomic mass percentage of each component. The raw materials weighed in S2 are heated to a molten state under an inert atmosphere and smelted, and then amorphous thin ribbons are prepared using a ribbon spinning machine. S3 winds amorphous thin strips into magnetic rings; The S4 magnetic ring was placed in an annealing furnace and annealed under an inert atmosphere. The process included heating from room temperature to 360 < T < 420 ℃ at a uniform rate for 90 to 120 minutes, holding at temperature T for 60 to 120 minutes, applying a longitudinal magnetic field to the magnetic ring at the beginning of the holding, and cooling it to 120 ℃ with the furnace after the holding was completed. The longitudinal magnetic field was then stopped and the furnace door was opened to cool it to room temperature, thus obtaining a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness.

[0012] Preferably, in step S1 above, before weighing the raw materials, the oxide layer of the easily oxidized raw materials is removed, and the materials are sealed after treatment to prevent re-oxidation.

[0013] Preferably, in step S2 above, the raw materials are heated to a molten state for 12 to 20 minutes during smelting, and then the temperature is maintained for 5 to 10 minutes to homogenize the alloy.

[0014] Preferably, in step S2 above, after melting is completed, an inert gas is used to spray the molten alloy, and the temperature cooling rate of the molten alloy flowing from the nozzle to the high-speed rotating copper roller strip is controlled to reach 10. 5 ~10 6 K / s.

[0015] Preferably, in step S2 above, the thickness of the amorphous thin strip prepared by the strip spinning machine is 20-26 μm.

[0016] Preferably, in step S4 above, a copper rod is inserted into the magnetic ring without the two touching, and different magnitudes of magnetic fields can be generated by connecting the copper rod to the circuit and passing different magnitudes of current.

[0017] In a further preferred embodiment, the central axis and copper rod of the magnetic ring are both set to be vertical, the inner diameter of the magnetic ring is 12-24 mm, the outer diameter is 16-28 mm, and the magnetic field strength is 0.008-0.024 T.

[0018] Preferably, in step S4 above, after closing the furnace door, a vacuum is first drawn and then an inert atmosphere gas is introduced. The inert atmosphere gas is argon or nitrogen.

[0019] Another technical solution provided by the present invention: a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness prepared by the above preparation method.

[0020] Preferably, the coercivity H of the above-mentioned cobalt-based amorphous alloy magnetic ring is... c The hysteresis loss P is 0.2–0.4 A / m. h It ranges from 0.7 to 1.0 J / m 3 Maximum permeability μ m 70×10 4 ~130×10 4 saturation magnetic induction intensity B sThe value is 0.55–0.65 T, and the rectangle ratio is B. r / B s The value ranges from 0.96 to 0.98.

[0021] Compared with the prior art, the beneficial effects of the present invention are: The method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness, by optimizing the component ratio and longitudinal magnetic field annealing process, yields a cobalt-based amorphous alloy magnetic ring with high squareness, low coercivity, low loss, and high maximum permeability. It has excellent characteristics such as fast response, high sensitivity, and temperature stability. The prepared cobalt-based amorphous alloy magnetic ring is suitable for high-frequency inductors, sensors, electromagnetic shielding and other fields. Attached Figure Description

[0022] Figure 1 The XRD patterns are those of the samples prepared in Example 1 and Comparative Examples 1 to 3 of this invention. Figure 2 The hysteresis loop and coercivity H of the cobalt-based amorphous alloy magnetic ring prepared in Example 1 of this invention are shown. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B s Parameter values; Figure 3 The hysteresis loop and coercivity H of the cobalt-based amorphous alloy magnetic ring prepared in Example 2 of this invention are shown. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B s Parameter values; Figure 4 The hysteresis loop and coercivity H of the cobalt-based amorphous alloy magnetic ring prepared in Example 3 of this invention are shown. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B s Parameter values; Figure 5 The hysteresis loop and coercivity H of the cobalt-based amorphous alloy magnetic ring prepared in Comparative Example 1 of this invention are shown. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B s Parameter values; Figure 6 The hysteresis loop and coercivity H of the cobalt-based amorphous alloy magnetic ring prepared in Comparative Example 2 of this invention are shown. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B s Parameter values; Figure 7 The hysteresis loop and coercivity H of the cobalt-based amorphous alloy magnetic ring prepared in Comparative Example 3 of this invention are shown. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B s The parameter value. Detailed Implementation

[0023] This invention aims to overcome the shortcomings of existing technologies by optimizing the composition ratio and preparation process through extensive experiments, particularly the finely controlled annealing heat treatment regime, to prepare a cobalt-based amorphous alloy magnetic ring with excellent comprehensive soft magnetic properties and high hysteresis loop squareness. The preparation method includes the following specific steps: The cobalt-based amorphous alloy magnetic ring material to be prepared contains, by mass percentage, Fe: 4.3–4.5%, Ni: 0.8–1.1%, Si: 8–8.5%, B: 2.9–3.3%, W: 0.3–0.6%, with the balance being Co and unavoidable trace impurities, wherein W is La or Gd; the raw materials are weighed according to the atomic mass percentage of each component. Before weighing, you can choose to further process the elemental raw materials. First, remove the oxide layer of the easily oxidized raw materials. After processing, seal the raw materials to prevent re-oxidation. The processing method can be grinding with a grinding wheel.

[0024] The weighed raw materials are heated to a molten state under an inert atmosphere and smelted. The molten alloy is then prepared into an amorphous ribbon using a ribbon spinning machine (using an inert gas to spray out the molten alloy). For reference, the thickness of the amorphous ribbon prepared by the ribbon spinning machine should be 20-26 μm. In a preferred embodiment, the raw materials are heated to a molten state for 12 to 20 minutes during melting, and then the temperature is maintained for 5 to 10 minutes to homogenize the alloy. Further preferably, the temperature cooling rate of the molten alloy flowing from the nozzle to the high-speed rotating copper roller forming the strip reaches 10. 5 ~10 6K / s, according to the test, the amorphous ribbon structure produced at this cooling rate is uniform, the internal stress distribution is uniform, and the surface condition is excellent. For reference, the following parameters can be used for control: nozzle slit is 0.3-0.7 mm, and linear velocity is 20-35 m / s.

[0025] After the amorphous thin strip is wound into a magnetic ring, it is placed in an annealing furnace and annealed in an inert atmosphere (specifically, the furnace door can be closed, a vacuum can be drawn first, and then argon or nitrogen can be introduced). The annealing process includes heating from room temperature to 360 < T < 420 ℃ at a uniform rate for 90 to 120 minutes, holding at temperature T for 60 to 120 minutes, applying a longitudinal magnetic field to the magnetic ring at the beginning of the holding, and cooling it to 120 ℃ with the furnace after the holding is completed. The longitudinal magnetic field is then stopped, the furnace door is opened, and the ring is cooled to room temperature to obtain a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness. The aforementioned longitudinal magnetic field can be generated by inserting a copper rod through a magnetic ring without the two touching, and then connecting the copper rod to a circuit and passing different currents to generate magnetic fields of different magnitudes. In a preferred embodiment, the central axis and copper rod of the magnetic ring are both set to be vertical, the inner diameter of the magnetic ring is 12-24 mm, the outer diameter is 16-28 mm, and the magnetic field strength is 0.008-0.024T.

[0026] The coercivity H of the cobalt-based amorphous alloy magnetic ring prepared by the method of the present invention is... c It can be controlled within 0.2–0.4 A / m, and the hysteresis loss P h It ranges from 0.7 to 1.0 J / m 3 Maximum permeability μ m 70×10 4 ~130×10 4 saturation magnetic induction intensity B s The value is 0.55–0.65 T, and the rectangle ratio is B. r / B s The value ranges from 0.96 to 0.98.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings, embodiments, and comparative examples. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] Example 1: Step 1: Prepare cobalt-based amorphous alloy raw materials using raw materials with a purity greater than 99%. The composition, by weight percentage, includes Fe: 4.43%, Ni: 0.88%, Si: 8.22%, B: 3.16%, La: 0.38%, with the remainder being Co and unavoidable trace impurities. Step 2: The raw materials prepared in Step 1 are placed in a quartz test tube, weighing 3 kg, and then placed in a vacuum strip spinning machine for melting under an argon atmosphere. The alloy is first heated to a molten state for 15 minutes, then held at that temperature for 8 minutes to ensure uniform melting. After uniform melting, the distance between the nozzle and the copper roller of the strip spinning machine, the rotation speed of the high-speed rotating copper roller, and the injection pressure of the molten alloy are controlled to ensure that the temperature cooling rate of the molten alloy flowing from the nozzle to the high-speed rotating copper roller to form the strip reaches 10°C. 5 ~10 6 K / s, under an argon atmosphere, molten alloy liquid was sprayed out to obtain a cobalt-based amorphous alloy thin strip with a thickness of 22 μm; Step 3: Use an automatic winding machine to wind the cobalt-based amorphous thin strip obtained in Step 2 into a magnetic ring with an outer diameter of 19 mm and an inner diameter of 15 mm.

[0029] Step 4: Using a longitudinal magnetic field annealing furnace, the cobalt-based amorphous alloy magnetic ring obtained in Step 3 is subjected to longitudinal magnetic field heat treatment. Specifically: the magnetic ring is inserted into a vertical copper rod in the annealing furnace, the copper rod is connected to a circuit, the furnace door is closed, a vacuum is first drawn and then nitrogen is introduced, and the temperature is raised from room temperature to 400 ℃ at a uniform rate for 90 minutes; it is then held at 400 ℃ for 80 minutes; at the beginning of the holding period, current is passed through the copper rod to generate a longitudinal magnetic field with a magnetic field strength of 0.01 T; after the holding period, the furnace is cooled to 120 ℃, the current is turned off, and the furnace door is opened to cool to room temperature.

[0030] Example 2: The difference between this embodiment and Embodiment 1 is that: the temperature is maintained at 400 ℃ for 60 minutes; at the beginning of the temperature maintenance, an electric current is passed through the copper rod to generate a longitudinal magnetic field with a magnetic field strength of 0.008 T; the remaining steps are the same as in Embodiment 1.

[0031] Example 3: The difference between this embodiment and Embodiment 1 is that the temperature is maintained at 380 ℃ for 120 minutes; at the beginning of the temperature maintenance, an electric current is passed through the copper rod to generate a longitudinal magnetic field with a magnetic field strength of 0.021 T; the remaining steps are the same as in Embodiment 1.

[0032] like Figures 2 to 4 As shown, the cobalt-based amorphous alloy magnetic rings prepared in Examples 1 to 3, after testing, exhibited a coercivity H. c All are less than 0.4 A / m, hysteresis loss P h All less than 1 J / m 3 Maximum permeability μ m All are greater than 70×104 saturation magnetic induction intensity B s Both are greater than 0.55 T, and the rectangle ratio is B. r / B s None of them are lower than 0.96.

[0033] Comparative Example 1: The difference between this comparative example and Example 1 is that: at the beginning of the heat preservation, no current is passed through the copper rod to generate a longitudinal magnetic field; the remaining steps are the same as in Example 1.

[0034] Comparative Example 2: The difference between this comparative example and Example 1 is that the cobalt-based amorphous alloy magnetic ring material to be prepared contains, by mass percentage, Fe: 2.26%, Ni: 0.88%, Si: 9.05%, B: 3.16%, La: 0.38%, with the remainder being Co and unavoidable trace impurities; the remaining steps are the same as in Example 1.

[0035] Comparative Example 3: The difference between this comparative example and Example 1 is that the cobalt-based amorphous alloy magnetic ring material to be prepared contains, by mass percentage, Fe: 4.7%, Ni: 0.88%, Si: 9.05%, B: 3.16%, La: 0.38%, with the remainder being Co and unavoidable trace impurities; the remaining steps are the same as in Example 1.

[0036] Figure 1 The XRD patterns of Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are shown. The XRD patterns were measured using a D8 Advance polycrystalline X-ray diffractometer. It can be seen that all three exhibit typical peak shapes, indicating that Example 1, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are amorphous structures.

[0037] Figure 2 , Figure 3 , Figure 4 The figures shown are the hysteresis loop diagrams and coercivity H of Examples 1, 2, and 3, respectively. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B s The parameter values. It can be seen that B in Examples 1, 2, and 3... r / B s All values ​​remained at or above 0.96, indicating that within a suitable heat treatment range, this cobalt-based amorphous magnetic ring can generally achieve extremely high B values. r / B s Furthermore, comparing H in Example 1, Example 2, and Example 3... cIt can be seen that as the heat treatment temperature increases or the holding time increases, the H of this cobalt-based amorphous magnetic ring decreases. c It has decreased somewhat.

[0038] Figure 5 The diagram shown is the hysteresis loop and coercivity H of Comparative Example 1. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B s The parameter values ​​are shown. It can be seen that, in Comparative Example 1, the coercivity H of the cobalt-based amorphous magnetic ring after annealing without a magnetic field is... c With a maximum permeability of 0.904 A / m and a maximum permeability μ m Only 11.5×10 4 , saturation magnetic induction intensity B s The value is 0.588 T, and the rectangle ratio is B. r / B s Only 0.41; Example 1, that is, the coercivity H of the quenched cobalt-based amorphous magnetic ring after annealing in a longitudinal magnetic field. c Reduced to 0.297 A / m, maximum permeability μ m Increased to 122.4×10 4 saturation magnetic induction intensity B s Rising to 0.596 T, the rectangle ratio B r / B s The value is as high as 0.97. Comparatively, it can be seen that after longitudinal magnetic field heat treatment, the overall soft magnetic properties of the cobalt-based amorphous alloy magnetic ring, including coercivity, hysteresis loss, maximum permeability, and saturation magnetic induction, are significantly improved, and the rectangularity ratio B... r / B s It has also been significantly improved.

[0039] Figure 6 , Figure 7 The figures shown are the hysteresis loops and coercivity H of Comparative Examples 2 and 3, respectively. c Hysteresis loss P h Maximum permeability μ m , saturation magnetic induction intensity B s Compared to the rectangle B r / B sThe parameter values ​​are as follows. In Comparative Example 2, the weight percentage of Fe is 2.26% and the weight percentage of Si is 9.05%. Compared to Example 1, the weight percentage of Fe is lower (less than 4.3%) and the weight percentage of Si is slightly higher (greater than 8.5%). In Comparative Example 3, the weight percentage of Fe is 4.7% and the weight percentage of Si is 9.05%. Compared to Example 1, the weight percentage of Fe is slightly higher (greater than 4.5%) and the weight percentage of Si is slightly higher (greater than 8.5%). It can be seen that after changing the Fe and Si content, the soft magnetic properties, including coercivity, hysteresis loss, maximum permeability, and saturation magnetic induction, significantly deteriorate, and the rectangularity ratio B... r / B s It also dropped significantly.

[0040] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

[0041] Any aspects of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness, characterized in that, Includes the following: The cobalt-based amorphous alloy magnetic ring material to be prepared, by mass percentage, includes Fe: 4.3–4.5%, Ni: 0.8–1.1%, Si: 8–8.5%, B: 2.9–3.3%, W: 0.3–0.6%, with the balance being Co and unavoidable trace impurities, wherein W is La or Gd; the raw materials are weighed according to the atomic mass percentage of each component. The raw materials weighed in S2 are heated to a molten state under an inert atmosphere and smelted, and then amorphous thin ribbons are prepared using a ribbon spinning machine. S3 winds amorphous thin strips into magnetic rings; The S4 magnetic ring was placed in an annealing furnace and annealed under an inert atmosphere. The process included heating from room temperature to 360 < T < 420 ℃ at a uniform rate for 90 to 120 minutes, holding at temperature T for 60 to 120 minutes, applying a longitudinal magnetic field to the magnetic ring at the beginning of the holding, and cooling it to 120 ℃ with the furnace after the holding was completed. The longitudinal magnetic field was then stopped and the furnace door was opened to cool it to room temperature, thus obtaining a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness.

2. The method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness according to claim 1, characterized in that: In step S1, before weighing the raw materials, the oxide layer of the easily oxidized raw materials is removed, and the materials are sealed after treatment to prevent re-oxidation.

3. The method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness according to claim 1, characterized in that: In step S2, the raw materials are heated to a molten state for 12 to 20 minutes during smelting, and then the temperature is maintained for 5 to 10 minutes to homogenize the alloy.

4. The method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness according to claim 1, characterized in that: In step S2, after melting is completed, an inert gas is used to spray the molten alloy, and the temperature cooling rate of the molten alloy flowing from the nozzle to the high-speed rotating copper roller strip is controlled to reach 10. 5 ~10 6 K / s.

5. The method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness according to claim 1, characterized in that: In step S2, the thickness of the amorphous thin strip prepared by the strip spinning machine is 20-26 μm.

6. The method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness according to claim 1, characterized in that: In step S4, a copper rod is inserted into the magnetic ring without the two touching. Different magnitudes of magnetic fields are generated by connecting the copper rod to the circuit and passing different magnitudes of current through it.

7. The method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness according to claim 6, characterized in that: The central axis and copper rod of the magnetic ring are both set vertically. The inner diameter of the magnetic ring is 12-24 mm, the outer diameter is 16-28 mm, and the magnetic field strength is 0.008-0.024 T.

8. The method for preparing a cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness according to claim 1, characterized in that: In step S4, after closing the furnace door, a vacuum is first drawn and then an inert atmosphere gas is introduced. The inert atmosphere gas is argon or nitrogen.

9. A cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness prepared by the preparation method according to any one of claims 1 to 8.

10. A cobalt-based amorphous alloy magnetic ring with high hysteresis loop squareness according to claim 9, characterized in that: The coercivity H of the cobalt-based amorphous alloy magnetic ring c The hysteresis loss P is 0.2–0.4 A / m. h It ranges from 0.7 to 1.0 J / m 3 Maximum permeability μ m 70×10 4 ~130×10 4 saturation magnetic induction intensity B s The value is 0.55–0.65 T, and the rectangle ratio is B. r / B s The value ranges from 0.96 to 0.98.

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