Iron-based amorphous alloy strip with high tensile plasticity and work hardening capacity and preparation method of iron-based amorphous alloy strip

Abstract

The invention discloses an iron-based amorphous alloy strip with high tensile plasticity and work hardening capacity and a preparation method thereof, the tensile plasticity of the iron-based amorphous alloy strip is obviously improved through cold and hot cycle treatment, the work hardening capacity of the obtained iron-based amorphous alloy strip is remarkable, and the yield ratio is 0.6-0.9 within the temperature range of 0.65 Tg to 0.9 Tg. According to the method, on the basis that the tensile plasticity of the iron-based amorphous alloy strip is remarkably improved through cold and hot circulation treatment, the excellent soft magnetic performance of the iron-based amorphous alloy strip is kept, the saturation flux density reaches 1.4-1.7 T, and loss is obviously reduced. According to the method, the amorphous alloy sample form is not damaged, the treatment time is short, the applicability is high, and the application prospect of the iron-based amorphous magnetically soft alloy serving as a structural functional material can be greatly expanded.

Description

Technical Field

[0001] The present invention belongs to the technical field of amorphous soft magnetic materials, and particularly relates to an iron-based amorphous alloy strip with both large tensile plasticity and work hardening ability and a preparation method thereof. Background Art

[0002] Iron-based amorphous alloys have excellent soft magnetic properties such as high saturation magnetic induction intensity, high initial magnetic permeability, and low medium and high-frequency losses. They have been widely used in fields such as power electronics, information communication, and new energy vehicles, and also have potential application prospects in high-tech fields such as national defense and aerospace. However, iron-based amorphous alloys generally lack the ability of macroscopic plastic deformation, resulting in limited processing performance and affecting their stability during the manufacturing and use of iron cores. Therefore, obtaining an iron-based amorphous soft magnetic alloy with both excellent toughness and comprehensive soft magnetic properties has important value for practical applications, and researchers have carried out a number of studies accordingly.

[0003] Patent CN104131243B discloses an iron-based amorphous alloy that is not brittle during annealing and a preparation method thereof. This invention improves the annealing toughness of the iron-based amorphous alloy by adding Ni element and M element (M = Nb, V, Ta, Ti), so that the amorphous alloy strip does not break when folded after annealing. However, the addition of these elements will reduce the saturation magnetic induction intensity of the iron-based amorphous alloy.

[0004] Patent CN112553545B discloses a high-toughness and anti-short-circuit iron-based amorphous soft magnetic alloy, a preparation method and applications thereof. This invention adds one or two elements of Dy, Er, and Yb with a content of 0.05 - 1.5 at% in the raw material components to prepare an amorphous soft magnetic alloy with both low loss and high toughness. The strip does not break when folded 180°, ensuring that the strip does not brittlely break and generate debris during sudden short circuit of the amorphous transformer. However, this method adds rare earth elements, resulting in a high cost, and the toughness ε of the strip measured by the flat plate bending method is only increased by about 14% compared with the comparative example, with limited improvement in the plasticity of the strip.

[0005] Patent CN112725709A discloses a surface modification method for improving the room temperature plasticity of iron-based amorphous alloys. This invention improves and enhances the room temperature plasticity of iron-based amorphous by shot peening the surface of the iron-based amorphous, but this patent is prone to forming microcracks on the surface of the specimen, resulting in the relaxation or redistribution of the shot peening residual stress field, and it is not applicable to iron-based amorphous alloy strips.

[0006] Patent CN115433812A discloses a method for enhancing the tensile plasticity of a toughened iron-based amorphous soft magnetic alloy strip. The prepared iron-based amorphous soft magnetic alloy strip is subjected to alternating hot and cold cycle treatment. However, the iron-based amorphous soft magnetic alloy strip obtained by this patent can only obtain a tensile plasticity of more than 4% when the temperature reaches 643K and 693K, and the saturation magnetic induction intensity is relatively low, about 1.0T.

[0007] Therefore, it is urgent to solve the problem of brittleness of iron-based amorphous alloys caused by traditional annealing treatment, the problem of affecting their processing performance and the generation of debris due to brittle fracture during use, and the problem of core loss existing in the preparation process. Summary of the Invention

[0008] Object of the Invention: Aiming at the problems existing in the prior art, the technical problem to be solved by the present invention is to provide an iron-based amorphous alloy strip with both large tensile plasticity and work hardening ability and a preparation method thereof, aiming to solve the problem that traditional annealing treatment causes the iron-based amorphous alloy to become brittle, thereby affecting its processing performance and the generation of debris due to brittle fracture during use. Moreover, the present invention can significantly reduce the core loss of the iron-based amorphous alloy strip prepared, and obtain excellent comprehensive soft magnetic properties.

[0009] Another technical problem to be solved by the present invention is to prepare an iron-based amorphous alloy strip with both large tensile plasticity, work hardening ability and excellent comprehensive soft magnetic properties by using this method.

[0010] Technical Solution: To solve the above technical problems, the present invention provides a preparation method of an iron-based amorphous alloy strip with both large tensile plasticity and work hardening ability. The preparation method includes alternately placing the iron-based amorphous alloy strip in an oil bath and liquid nitrogen for multiple thermal cycling treatments. One cycle of the thermal cycling treatment is to first perform an oil bath treatment for 5 s to 5 min and then perform a liquid nitrogen treatment for 5 s to 5 min. The temperature of the oil bath treatment is 0.45T g ~0.75T g (T g is the glass transition temperature).

[0011] Among them, after the thermal cycling treatment, the tensile plasticity of the iron-based amorphous alloy strip is greater than 2% in the temperature range of 0.65T g ~0.9T g (T g is the glass transition temperature).

[0012] Furthermore, after the thermal cycling treatment, the yield ratio of the iron-based amorphous alloy strip is 0.6 to 0.9 in the temperature range of 0.65T g ~0.9T g temperature range.

[0013] Furthermore, after the thermal cycling treatment, the saturation magnetic induction intensity of the iron-based amorphous alloy strip is 1.4T to 1.7T.

[0014] Further, the oil viscosity of the oil bath is 50 cst to 200 cst. For example, it can be 50 cst, 100 cst, 200 cst, etc., but is not limited to the listed values. Other unlisted values within this range are equally applicable.

[0015] Among them, the total duration of the multiple cold and hot cycle treatments is 10 min to 120 min. Preferably, the total duration of the multiple cold and hot cycle treatments is 15 min to 90 min. For example, it can be 15 min, 30 min, 40 min, 50 min, 90 min, etc., but is not limited to the listed values. Other unlisted values within this range are equally applicable.

[0016] Among them, the single oil bath treatment time of the cold and hot cycle treatment is 10 s to 3 min. Preferably, the single liquid nitrogen treatment time of the cold and hot cycle treatment is 10 s to 3 min.

[0017] Among them, the chemical composition of the iron-based amorphous soft magnetic alloy strip is Fe a Co b Si c M d , where a, b, c, and d respectively represent the atomic percentages of the corresponding elements, M is one or more of the elements B, P, or C, 67 ≤ a ≤ 83, 0 ≤ b ≤ 16, 2 ≤ c ≤ 7, 10 ≤ d ≤ 15, and a + b + c + d = 100.

[0018] Further, the thickness of the iron-based amorphous alloy strip is 15 μm to 30 μm. For example, it can be 15 μm, 18 μm, 20 μm, 22 μm, 26 μm, 30 μm, etc., but is not limited to the listed values. Other unlisted values within this range are equally applicable.

[0019] Among them, the preparation method steps of the iron-based amorphous alloy strip are as follows: The raw materials containing Fe, Co, Si, and M elements are subjected to induction melting under high-purity argon protection, and after cooling, a homogeneous master alloy ingot is obtained. The master alloy ingot material is prepared into an iron-based amorphous alloy strip by the single-roll rapid quenching method, and the M is one or more of the elements B, P, or C.

[0020] Among them, the preparation method further includes placing the prepared amorphous alloy strip in an alcohol solution for ultrasonic cleaning and drying to obtain an iron-based amorphous alloy strip. Preferably, the ultrasonic cleaning time is 10 min to 30 min. For example, it can be 10 min, 12 min, 15 min, 20 min, 30 min, etc., but is not limited to the listed values. Other unlisted values within this range are equally applicable.

[0021] The iron-based amorphous alloy strip prepared by the preparation method described in the present invention.

[0022] A kind of iron-based amorphous alloy strip with both large tensile plasticity and work hardening ability and its preparation method according to the present invention specifically includes the following steps:

[0023] Step 1: The prepared raw materials are subjected to induction melting under the protection of high-purity argon gas, and after cooling, a master alloy ingot with uniform composition is obtained. The master alloy ingot material is prepared into an iron-based amorphous alloy strip by the single-roll rapid cooling method;

[0024] Step 2: The amorphous alloy strip is alternately placed in an oil bath and liquid nitrogen for thermal cycling treatment; one cycle of the thermal cycling treatment is to first perform oil bath treatment for 5 s to 5 min and then perform liquid nitrogen treatment for 5 s to 5 min. Among them, the temperature of the oil bath treatment is 0.45T g ~0.75T g ;

[0025] Step 3: The amorphous alloy strip obtained in Step 2 is ultrasonically cleaned and dried in an alcohol solution to obtain the iron-based amorphous alloy strip.

[0026] Beneficial effects: Compared with the prior art, the present invention has the following advantages: The present invention provides an iron-based amorphous alloy strip with both large tensile plasticity and work hardening ability and its preparation method, which significantly optimizes the tensile properties of the iron-based amorphous alloy strip and can significantly reduce the core loss of the iron-based amorphous alloy strip prepared. Specifically, it includes the following aspects:

[0027] (1) The present invention significantly improves the tensile plasticity of the iron-based amorphous alloy strip through thermal cycling treatment. The obtained iron-based amorphous alloy strip has remarkable work hardening ability, and the yield strength ratio is 0.6 to 0.9 in the temperature range of 0.65T g ~0.9T g temperature range.

[0028] (2) On the basis of significantly improving the tensile plasticity of the iron-based amorphous alloy strip through thermal cycling treatment, the present invention maintains its excellent soft magnetic properties. The saturation magnetic induction intensity reaches 1.4T to 1.7T, and the loss is significantly reduced.

[0029] (3) The present invention has no damage to the morphology of the amorphous alloy sample, short treatment time, strong applicability, and can greatly expand the application prospect of the iron-based amorphous soft magnetic alloy as a structural functional material. Description of the Drawings

[0030] Figure 1 is the X-ray diffraction pattern of the amorphous alloy strips prepared in Example 1, Example 2 and Comparative Example 1;

[0031] Figure 2 is the tensile stress-strain curve of the amorphous alloy strips prepared in Example 1 and Comparative Example 1 at 533K;

[0032] Figure 3 It is the DSC curve graph of the amorphous alloy strip prepared in Example 2 and Comparative Example 1;

[0033] Figure 4 It is the hysteresis loop curve graph of the amorphous alloy strips prepared in Example 1, Example 2 and Comparative Example 1;

[0034] Figure 5 It is the change curve graph of the loss of the amorphous alloy strips prepared in Example 1, Example 2 and Comparative Example 1 with the magnetic flux density at 50 Hz.

[0035] Figure 6 It is the change curve graph of the loss of the amorphous alloy strips prepared in Example 1, Example 2 and Comparative Example 1 with the magnetic flux density at 1 kHz after being wound into iron cores. Detailed implementation manners

[0036] To further illustrate the content of the present invention, the present invention will be described in detail below in conjunction with the drawings and embodiments.

[0037] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention.

[0038] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific implementation manners of the present invention specification, which are obvious to those skilled in the art. The present invention specification and embodiments are only exemplary, and any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention. Regarding the use of "including", "having", etc. herein, they are all open-ended terms, that is, they are intended to include but not limited to.

[0039] Example 1 Preparation of an iron-based amorphous alloy with the molecular formula Fe 75 Co 8 B 10 Si 3 C 3 P 1 by hot and cold cycle treatment

[0040] A method for preparing an iron-based amorphous alloy strip with both large tensile plasticity, work hardening ability and excellent comprehensive soft magnetic properties, the specific steps are as follows:

[0041] (1) Iron blocks, cobalt blocks, boron particles, silicon particles, iron phosphide particles (the mass percentage of phosphorus is 26.4%) purchased from Zhongnuo New Materials (Beijing) Technology Co., Ltd., and iron-carbon blocks (the mass percentage of carbon is 5%) purchased from Beijing Zhongjinyan New Materials Technology Co., Ltd. were respectively prepared according to the formula Fe 75 Co 8 B 10 Si 3 C 3 P 1 The atomic percentage is adjusted to obtain 20g of the mixture. The prepared mixture is melted in an induction melting furnace under argon protection (melting temperature is 1250°C to 1350°C) to obtain a master alloy ingot with uniform composition;

[0042] (2) The mother alloy ingot is crushed and loaded into a quartz tube with a nozzle at the bottom, and the quartz tube is fixed in an induction coil. Under the protection of high-purity argon, the small alloy ingot is quickly molten by induction heating. Then the heating power is turned off, and the alloy melt is cooled to a state where the surface is slightly shaken (1080°C to 1130°C). The single-roller rapid cooling strip method is used to use the pressure difference between the quartz tube and the cavity to quickly spray the molten alloy liquid onto the surface of a high-speed rotating copper roller for rapid cooling, thereby preparing an amorphous alloy strip with a thickness of about 16 μm;

[0043] (3) The amorphous alloy strip is placed in an oil bath and liquid nitrogen alternately for hot and cold cycle treatment; one cycle of the hot and cold cycle treatment is first 30 seconds of oil bath treatment and then 30 seconds of liquid nitrogen treatment, wherein the oil bath treatment temperature is 463K (0.69T g ), the oil viscosity of the oil bath is 100 cst, and then repeated hot and cold cycle treatment is performed, and the total duration of the hot and cold cycle treatment is 30 minutes. Then it is naturally restored to room temperature in the air;

[0044] (4) The amorphous alloy strip after the hot and cold cycle treatment is placed in an alcohol solution for ultrasonic cleaning for 10 minutes and then dried.

[0045] Example 2 Preparation of a molecule with the molecular formula Fe by hot and cold cycle treatment 75 Co 8 B 10 Si 3 C 3 P 1 Iron-based amorphous alloy

[0046] A method for preparing an iron-based amorphous alloy strip having large tensile plasticity, work hardening ability and excellent comprehensive soft magnetic properties, the specific steps are as follows:

[0047] (1) Iron blocks, cobalt blocks, boron particles, silicon particles, iron phosphide particles (mass percentage of phosphorus is 26.4%) purchased from Zhongnuo New Materials (Beijing) Technology Co., Ltd. and iron-carbon blocks (mass percentage of carbon is 5%) purchased from Beijing Zhongjinyan New Materials Technology Co., Ltd. were respectively proportioned according to the atomic percentages of Fe 75 Co 8 B 10 Si 3 C 3 P 1 to obtain 20 g of a mixed material. The prepared mixed material was melted using an induction melting furnace under argon protection (melting temperature was 1250 °C to 1350 °C) to obtain a master alloy ingot with uniform composition;

[0048] (2) The master alloy ingot was crushed and placed into a quartz tube with a nozzle at the bottom. The quartz tube was fixed in an induction coil. Under high-purity argon protection, the small alloy ingots were quickly brought to a molten state by induction heating. Then, the heating power supply was turned off. When the alloy melt cooled to a state where the surface slightly vibrated (1080 °C to 1130 °C), the single-roll rapid quenching and strip casting method was used to quickly spray the molten alloy liquid onto the surface of a rapidly rotating copper roll for rapid cooling using the air pressure difference inside the quartz tube and the cavity, to prepare an amorphous alloy strip with a thickness of about 16 μm;

[0049] (3) The amorphous alloy strip was alternately placed in an oil bath and liquid nitrogen for thermal cycling treatment; one cycle of the thermal cycling treatment was to first perform 15 s of oil bath treatment and then 15 s of liquid nitrogen treatment. Among them, the oil bath treatment temperature was 463 K (0.69 T g ), the oil viscosity of the oil bath was 100 cst, and then repeated thermal cycling treatment was carried out. The total duration of the thermal cycling treatment was 30 min. Subsequently, it was naturally restored to room temperature in the air;

[0050] (4) The amorphous alloy strip after thermal cycling treatment was ultrasonically cleaned in an alcohol solution for 30 min and then dried.

[0051] Comparative Example 1 prepared an iron-based amorphous alloy with the molecular formula Fe 75 Co 8 B 10 Si 3 C 3 P 1 .

[0052] The preparation process of this Comparative Example 1 referred to Example 1, the difference being that no thermal cycling treatment was carried out (i.e., steps 3 and 4 were omitted), and the rest was the same as in Example 1.

[0053] X-ray diffraction (XRD) was used to measure the structures of the alloy strips prepared in Example 1, Example 2, and Comparative Example 1, as Figure 1As shown, the amorphous alloy samples prepared in Example 1, Example 2 and Comparative Example 1 all have only one diffuse diffraction peak, indicating that the thermal cycling treatment did not change the amorphous structure of the samples.

[0054] The thermal performance parameters of the amorphous alloy ribbons prepared in Example 2 and Comparative Example 1 were detected by a differential scanning calorimeter (DSC) with a heating rate of 20 K / min. As Figure 2 shown, the glass transition temperature T g and crystallization temperature T x of the samples before and after thermal cycling did not change significantly, indicating that the thermal cycling treatment did not change the thermal performance of the samples.

[0055] The tensile stress-strain curves of the amorphous alloy ribbons prepared in Example 1 and Comparative Example 1 at 533 K were measured by a dynamic mechanical analyzer (DMA). As Figure 3 shown, the tensile plasticity of the as-quenched amorphous alloy ribbon prepared in Comparative Example 1 was 2.8%, and the tensile plasticity of the amorphous alloy after thermal cycling treatment prepared in Example 1 was increased to 10% and had excellent work hardening ability, with a yield strength ratio of 0.67, indicating that the thermal cycling treatment can significantly improve the mechanical properties of iron-based amorphous alloy ribbons.

[0056] The saturation magnetic induction intensity and the loss at 1 kHz of the samples in Example 1, Example 2 and Comparative Example 1 were tested by a vibrating sample magnetometer and an alternating current hysteresis loop measuring instrument. Figure 4 is the hysteresis loop curve of the amorphous alloy ribbon sample. The saturation magnetic induction intensities of the samples in Example 1 and Example 2 were 1.68 T and 1.70 T respectively, which were higher than that of the sample in Comparative Example 1 (1.65 T). Figure 5 is the curve of the loss varying with the magnetic flux density of the samples in Example 1, Example 2 and Comparative Example 1 at 1 kHz. The losses of the samples in Example 1 and Example 2 were significantly lower than that of the sample in Comparative Example 1, indicating that the method of the present invention is beneficial to improving the comprehensive soft magnetic properties of iron-based amorphous alloy ribbons.

[0057] Comparative Example 2

[0058] The preparation method of Comparative Example 2 was exactly the same as that of Example 2, and the only difference was that the oil bath temperature in step (3) was 563 K (0.84 T g ).

[0059] Due to the too high oil bath treatment temperature, the relaxation degree of the amorphous alloy was too large and too much free volume annihilation was not conducive to the mechanical properties of the ribbon. It was found by DSC test that the relaxation enthalpy of the amorphous alloy prepared in Comparative Example 2 was 296 J / mol, which was 48% lower than that of the sample with the same composition without thermal cycling treatment. After testing, the tensile plasticity of the amorphous alloy ribbon at 533 K was 2.1% and the yield strength ratio was 0.91, which was lower than that of the sample in terms of tensile plasticity.

[0060] Example 3 Preparation of Fe by hot and cold cycle treatment 80 Si 6 B 13 C 1 Iron-based amorphous alloy

[0061] (1) Iron blocks, boron particles, silicon particles with a purity of more than 99 wt.% purchased from Zhongnuo New Materials (Beijing) Technology Co., Ltd., and iron-carbon blocks (with a carbon mass percentage of 5%) purchased from Beijing Zhongjinyan New Materials Technology Co., Ltd. were respectively mixed according to the formula Fe 80 Si 6 B 13 C 1 The atomic percentage is adjusted to obtain 20g of the mixture. The prepared mixture is melted in an induction melting furnace under argon protection (melting temperature is 1250°C to 1350°C) to obtain a master alloy ingot with uniform composition;

[0062] (2) The mother alloy ingot is crushed and loaded into a quartz tube with a nozzle at the bottom, and the quartz tube is fixed in an induction coil. Under the protection of high-purity argon gas, the small alloy ingot is quickly molten by induction heating. Then the heating power is turned off, and the alloy melt is cooled to a state where the surface is slightly shaken (1080°C to 1130°C). The molten alloy liquid is quickly sprayed onto the surface of a high-speed rotating copper roller by a single-roller rapid cooling strip method using the pressure difference between the quartz tube and the cavity to quickly cool the molten alloy, thereby preparing an amorphous alloy strip with a thickness of about 22 μm;

[0063] (3) The amorphous alloy strip is placed in an oil bath and liquid nitrogen alternately for hot and cold cycle treatment; one cycle of the hot and cold cycle treatment is first a 60 s oil bath treatment and then a 60 s liquid nitrogen treatment, wherein the oil bath treatment temperature is 436K (0.60T g ), the oil viscosity of the oil bath is 50cst, and then repeated hot and cold cycle treatment is performed, and the total duration of the hot and cold cycle treatment is 60 minutes. Then it is naturally restored to room temperature in the air;

[0064] (4) The amorphous alloy strip after the hot and cold cycle treatment is placed in an alcohol solution for ultrasonic cleaning for 10 minutes and then dried.

[0065] The amorphous alloy strip prepared in this embodiment has a tensile plasticity of 3.3% at 453K, a yield strength ratio of 0.82, and a saturation magnetic induction intensity of 1.56T.

[0066] Comparative Example 3

[0067] The preparation method of Comparative Example 3 is exactly the same as that of Example 2, except that the oil bath temperature in step (3) is 298K (0.41T g ).

[0068] Due to the too low temperature of the oil bath treatment, the atomic diffusion rate during the oil bath treatment is low, which is not conducive to enhancing the effect of increasing the structural inhomogeneity of the amorphous alloy during the thermal cycling treatment. After testing, the tensile plasticity of the amorphous alloy strip is 1.6% at 453K, and the yield strength ratio is 0.9, showing a decrease in tensile plasticity compared to the sample.

[0069] Example 4 Preparation of an iron-based amorphous alloy with the molecular formula Fe 83 B 10 Si 3 C 3 P 1 iron-based amorphous alloy

[0070] (1) Respectively, iron blocks, boron particles, silicon particles, iron phosphide particles (with a phosphorus mass percentage of 26.4%) with a purity greater than 99wt.% purchased from Zhongnuo New Materials (Beijing) Technology Co., Ltd. and iron-carbon blocks (with a carbon mass percentage of 5%) purchased from Beijing Zhongjinyan New Materials Technology Co., Ltd. were proportioned according to the atomic percentages of the formula Fe 83 B 10 Si 3 C 3 P 1 to obtain 20g of a mixed material. The prepared mixed material was melted using an induction melting furnace under argon protection (the melting temperature was 1250°C - 1350°C) to obtain a master alloy ingot with uniform composition;

[0071] (2) After crushing the master alloy ingot, it was loaded into a quartz tube with a nozzle at the bottom. The quartz tube was fixed in an induction coil. Under the protection of high-purity argon, the small alloy ingot was quickly heated to the molten state by induction heating. Then, the heating power supply was turned off. When the alloy melt cooled to a state where the surface slightly vibrated (1080°C - 1130°C), the single-roll rapid quenching and strip casting method was used to quickly spray the molten alloy liquid onto the surface of a rapidly rotating copper roll for rapid cooling using the air pressure difference between the inside of the quartz tube and the cavity, to prepare an amorphous alloy strip with a thickness of about 30μm;

[0072] (3) The amorphous alloy strip was alternately placed in an oil bath and liquid nitrogen for thermal cycling treatment. One cycle of the thermal cycling treatment was to first perform 60s of oil bath treatment and then 60s of liquid nitrogen treatment. Among them, the oil bath treatment temperature was 507K (0.75T g ), the oil viscosity of the oil bath was 200cst, and then repeated thermal cycling treatment was carried out. The total duration of the thermal cycling treatment was 30min, and then it was naturally restored to room temperature in the air;

[0073] (4) The amorphous alloy strip after the thermal cycling treatment was ultrasonically cleaned in an alcohol solution for 15min and then dried.

[0074] The amorphous alloy strip prepared in this example has a tensile plasticity of 3.5% at 473K, a yield ratio of 0.81, and a saturation magnetic induction intensity of 1.59T.

[0075] Comparative Example 4

[0076] The preparation method of Comparative Example 4 is exactly the same as that of Example 3. The only difference is that one cycle of the thermal cycling treatment in step (3) is to first perform liquid nitrogen treatment for 60s and then perform oil bath treatment for 60s.

[0077] Since the last treatment step of the thermal cycling treatment is oil bath treatment, when the amorphous alloy strip is naturally cooled to room temperature in air, it will cause some reversible relaxation not to be activated. After testing, the tensile plasticity of this amorphous alloy strip is 1.8% at 473K, and the yield ratio is 0.89.

[0078] The molecular formula of the iron-based amorphous alloy prepared by thermal cycling treatment in Example 5 is Fe 67 Co 16 B 10 Si 3 C 3 P 1 The steps are as follows:

[0079] (1) Respectively, iron blocks, cobalt blocks, boron particles, silicon particles, iron phosphide particles (the mass percentage of phosphorus is 26.4%) with a purity greater than 99wt.% purchased from Zhongnuo New Materials (Beijing) Technology Co., Ltd. and iron-carbon blocks (the mass percentage of carbon is 5%) purchased from Beijing Zhongjinyan New Materials Technology Co., Ltd. are proportioned according to the atomic percentage of the formula Fe 67 Co 16 B 10 Si 3 C 3 P 1 to obtain 20g of a mixed material. The prepared mixed material is melted by an induction melting furnace under argon protection (the melting temperature is 1250°C - 1350°C) to obtain a master alloy ingot with uniform composition;

[0080] (2) After crushing the master alloy ingot, it is loaded into a quartz tube with a nozzle at the bottom. The quartz tube is fixed in an induction coil. Under the protection of high-purity argon, the small alloy ingot is quickly heated to the molten state by induction heating. Then, the heating power supply is turned off. When the alloy melt cools to a state where the surface slightly shakes (1080°C - 1130°C), the molten alloy liquid is quickly sprayed onto the surface of a rapidly rotating copper roller for rapid cooling by the pressure difference between the inside of the quartz tube and the cavity using the single-roll rapid quenching and belt casting method to prepare an amorphous alloy strip with a thickness of about 15μm;

[0081] (3) The amorphous alloy strip is placed alternately in an oil bath and liquid nitrogen for hot and cold cycle treatment. One cycle of the hot and cold cycle treatment is first a 2-min oil bath treatment and then a 2-min liquid nitrogen treatment. The oil bath treatment temperature is 507K (0.75T g ), the oil viscosity of the oil bath is 150cst, and then repeated hot and cold cycle treatment is performed, the total duration of the hot and cold cycle treatment is 120min, and then it is naturally restored to room temperature in the air;

[0082] (4) The amorphous alloy strip after the hot and cold cycle treatment is placed in an alcohol solution for ultrasonic cleaning for 15 minutes and then dried.

[0083] The amorphous alloy strip prepared in this embodiment has a tensile plasticity of 2.5% at 433K, a yield strength ratio of 0.85, and a saturation magnetic induction intensity of 1.73T.

[0084] Comparative Example 5

[0085] The preparation method of Comparative Example 5 is exactly the same as that of Implementation 4, with the only difference being that the single liquid nitrogen treatment time in step (3) is 10 min, and the single oil bath treatment time is 10 min.

[0086] Since the single liquid nitrogen treatment and oil bath treatment time is too long, the number of hot and cold cycles is reduced, the relaxation degree of the amorphous alloy is increased, and the effect of hot and cold cycle treatment on enhancing the structural inhomogeneity of the amorphous alloy is limited. According to the test, the tensile plasticity of the amorphous alloy strip at 433K is 1.6%, and the yield strength ratio is 0.91.

[0087] Example 6 Preparation of a cold and hot cycle treated molecule with the formula Fe 67 Co 16 B 10 Si 3 C 3 P 1 Iron-based amorphous alloy, the steps are:

[0088] (1) Iron blocks, cobalt blocks, boron particles, silicon particles, iron phosphide particles (the mass percentage of phosphorus is 26.4%) purchased from Zhongnuo New Materials (Beijing) Technology Co., Ltd., and iron-carbon blocks (the mass percentage of carbon is 5%) purchased from Beijing Zhongjinyan New Materials Technology Co., Ltd. were respectively prepared according to the formula Fe 67 Co 16 B 10 Si 3 C 3 P 1 The atomic percentage is adjusted to obtain 20g of the mixture. The prepared mixture is melted in an induction melting furnace under argon protection (melting temperature is 1250°C to 1350°C) to obtain a master alloy ingot with uniform composition;

[0089] (2) The master alloy ingot is crushed and then loaded into a quartz tube with a nozzle at the bottom. The quartz tube is fixed in an induction coil. Under the protection of high-purity argon, the small alloy ingot is quickly melted to a molten state by induction heating. Then, the heating power supply is turned off. When the alloy melt cools to a state where the surface slightly trembles (1080 °C - 1130 °C), the single-roll rapid quenching and strip casting technology is used to quickly spray the molten alloy liquid onto the surface of a rapidly rotating copper roll for rapid cooling by using the air pressure difference inside the quartz tube and the cavity, and an amorphous alloy strip with a thickness of about 30 μm is prepared;

[0090] (3) The amorphous alloy strip is alternately placed in an oil bath and liquid nitrogen for thermal cycling treatment. One cycle of the thermal cycling treatment is to first perform an oil bath treatment for 15 s and then a liquid nitrogen treatment for 15 s. Among them, the oil bath treatment temperature is 378 K (0.57 T g ), the oil viscosity of the oil bath is 100 cst, and then repeated thermal cycling treatment is carried out. The total duration of the thermal cycling treatment is 10 min, and then it is naturally restored to room temperature in the air;

[0091] (4) The amorphous alloy strip after thermal cycling treatment is placed in an alcohol solution and ultrasonically cleaned for 15 min and then dried.

[0092] The amorphous alloy strip prepared in this example has a tensile plasticity of 3.0% at 503 K, a yield ratio of 0.79, and a saturation magnetic induction intensity of 1.73 T.

[0093] Comparative Example 6

[0094] The preparation method of Comparative Example 6 is exactly the same as that of Example 5. The only difference is that in step (3), the single liquid nitrogen treatment time is 3 s and the single oil bath treatment time is 3 s.

[0095] Due to the too short single liquid nitrogen treatment and oil bath treatment time, the temperature distribution of the sample is uneven during the thermal cycling process, and the time is not enough for the strip to heat up / cool down to the oil bath / liquid nitrogen temperature during the thermal cycling process. After testing, the tensile plasticity of this amorphous alloy strip is 1.5% at 503 K, and the yield ratio is 0.9.

Claims

1. A method for preparing an iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability, characterized in that: The preparation method comprises placing the iron-based amorphous alloy strip alternately in an oil bath and liquid nitrogen for multiple hot and cold cycle treatments; one cycle of the hot and cold cycle treatments is firstly oil bath treatment for 5 s to 5 min and then liquid nitrogen treatment for 5 s to 5 min, and the oil bath treatment temperature is 0.45 T g ~ 0.75 T g .

2. The method for preparing an iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability according to claim 1, characterized in that: The oil bath treatment temperature is 0.65 T g ~ 0.9 T g .

3. The method for preparing the iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability according to claim 1, characterized in that: The oil viscosity of the oil bath is 50 cst to 200 cst.

4. The method for preparing the iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability according to claim 1, characterized in that: The total duration of the multiple hot and cold cycle treatments is 10 min to 120 min. Preferably, the total duration of the multiple hot and cold cycle treatments is 15 min to 90 min.

5. The method for preparing an iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability according to claim 1, characterized in that: The single oil bath treatment time of the hot and cold cycle treatment is 10 s to 3 min. Preferably, the single liquid nitrogen treatment time of the hot and cold cycle treatment is 10 s to 3 min.

6. The method for preparing an iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability according to claim 1, characterized in that: The chemical composition of the iron-based amorphous soft magnetic alloy strip is Fe a Co b Si c M d , where a, b, c, and d represent the atomic percentages of the corresponding elements, respectively, M is one or more of the B, P, or C elements, 67≤a≤83, 0≤b≤16, 2≤c≤7, 10≤d≤15, and a+b+c+d=100.

7. The method for preparing an iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability according to claim 1, characterized in that: The thickness of the iron-based amorphous alloy strip is 15 μm to 30 μm.

8. The method for preparing an iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability according to claim 1, characterized in that: The preparation method of the iron-based amorphous alloy strip comprises the following steps: induction melting of raw materials containing Fe, Co, Si and M elements under the protection of high-purity argon gas, obtaining a master alloy ingot with uniform composition after cooling, and preparing the master alloy ingot into an iron-based amorphous alloy strip by a single-roller rapid cooling method, wherein M is one or more of B, P or C elements.

9. The method for preparing an iron-based amorphous alloy strip having both large tensile plasticity and work hardening ability according to claim 1, characterized in that: The preparation method further comprises placing the prepared amorphous alloy strip in an alcohol solution for ultrasonic cleaning and drying to obtain an iron-based amorphous alloy strip. Preferably, the ultrasonic cleaning time is 10 min to 30 min.

10. The iron-based amorphous alloy strip prepared by the preparation method according to any one of claims 1 to 9.

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