Method for enhancing amorphous forming ability of high-saturation magnetic induction amorphous strip

Abstract

The invention relates to the technical field of amorphous material preparation, in particular to a method for enhancing the amorphous forming ability of a high-saturation magnetic induction amorphous strip, which comprises the following steps: S1, taking Fe, Si, B, Nb and Cu according to atomic percent, adding Y, Sc, Zr and La, mixing, and carrying out vacuum melting to generate LaB6 to prepare a master alloy ingot; s2, re-melting the master alloy to 1450-1500 DEG C, introducing argon, adding Ca-Si alloy for deoxidation, and filtering through a ceramic filter screen; s3, the melt is sprayed to a double-temperature-zone copper roller, and low-temperature nitrogen is supplemented for cooling; and S4, carrying out segmented annealing on the strip under vacuum, heating to 380-420 DEG C, preserving heat, cooling to 300-320 DEG C, preserving heat, and cooling along with the furnace. According to the method, through multi-element rare earth collaboration, melt deep purification, gradient quenching and other innovations, the amorphous forming ability is enhanced, high saturation magnetic induction is considered, the magnetic performance, mechanical performance and corrosion resistance of the strip are improved, and the production stability and the yield are high.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of amorphous material preparation, in particular to an amorphous forming capacity enhancement method for high-saturation-magnetic-induction amorphous ribbons. BACKGROUND

[0002] Amorphous ribbons have high saturation magnetic induction and low loss due to the disordered atomic arrangement and the absence of grain boundary defects, and are in urgent need in the fields of new energy automobile motors and power transformers. Among them, iron-based amorphous ribbons have become a research hotspot due to low cost and balanced magnetic properties, but the lack of amorphous forming capacity has always been the core bottleneck restricting the large-scale production and performance improvement of the amorphous ribbons.

[0003] In the prior art, Fe-Si-B ternary systems are often used for iron-based amorphous ribbons, and elements such as Nb and Cu are often added to enhance the amorphous forming capacity. However, the addition of such elements can easily lead to a decrease in saturation magnetic induction, making it difficult to meet the dual requirements of “high forming capacity” and “high saturation magnetic induction”. Some processes attempt to introduce a single rare earth element (such as Y or La), but the rare earth elements are easily oxidized and segregated in the melt, which not only fails to effectively play a role, but also reduces the magnetic properties and mechanical properties of the ribbon due to the inclusion of defects.

[0004] The melt purification process also has obvious defects. Traditional processes often rely on single argon protection, which cannot completely remove impurities such as oxygen and nitrogen in the melt. These impurities can easily form oxide and nitride inclusions during rapid solidification, which become heterogeneous nucleation points for amorphous formation, significantly increasing the critical cooling rate of amorphous formation, and leading to crystallization of the ribbon. At the same time, after purification, there is a lack of effective filtering means, and small inclusions in the melt directly enter the subsequent rapid cooling process, further deteriorating the quality of the ribbon.

[0005] In the rapid solidification process, the existing process often uses a single temperature copper roller for cooling, and the cooling rate is unevenly distributed, which can cause differences in cooling between the edge and the center of the ribbon, leading to crystallization at the edge and uneven thickness at the center. In addition, the cooling medium is often single air or inert gas, and the cooling efficiency is limited, making it difficult to meet the high cooling rate requirements of high alloy content melts.

[0006] Annealing is a key step for optimizing the performance of amorphous ribbons. Traditional processes often use constant temperature annealing, which cannot accurately control the relaxation process of amorphous atoms, and can easily lead to uneven stress distribution in the ribbon, resulting in large fluctuations in magnetic permeability. At the same time, the surface of the ribbon after annealing lacks effective protection, and is easily oxidized and corroded during subsequent processing and use, affecting the service life.

[0007] In addition, the links of the existing process lack systematic design, raw material pretreatment is rough, purification and quenching parameters are not matched, annealing and surface treatment are disconnected, and other problems are common, resulting in low qualified rate of strip production and poor performance consistency. Especially in large-scale production, due to insufficient amorphous forming ability, the strip is prone to crystallization, cracking and other defects, which greatly increases the production cost and is difficult to meet the batch demand of high-end equipment for high-performance amorphous strip. In summary, the preparation process of the existing high-saturation magnetic amorphous strip has multiple technical pain points in composition design, melt purification, cooling control and annealing treatment, and needs to be broken through to realize the synchronous improvement of performance and production efficiency. SUMMARY

[0008] (I) Technical problems solved In view of the deficiencies of the prior art, the present application provides a method for enhancing the amorphous forming ability of high-saturation magnetic amorphous strip.

[0009] (II) Technical solutions A method for enhancing the amorphous forming ability of high-saturation magnetic amorphous strip, comprising the following steps: S1. Raw material preparation: weigh Fe79-81%, Si3.5-4.5%, B6.5-7.5%, Nb1.2-1.8%, Cu0.6-0.9% according to atomic percentage, add 0.3-0.4% Y, 0.15-0.25% Sc, 0.08-0.12% Zr, and then add 0.03-0.06% La. Mix the above raw materials and place them in a vacuum melting furnace. Vacuumize to ≤-0.098 MPa, and heat to 1550-1600℃ for melting. During the melting process, La reacts with B to form LaB6, the reaction formula is La+6B→LaB6, and the alloy ingot is prepared by keeping the temperature for 35-40 min.

[0010] S2. Melt purification: put the master alloy ingot into an induction heating furnace and heat to 1450-1500℃ to remelt. Introduce argon gas with a purity of 99.999% into the furnace, and control the gas flow at 8-10 L / min. Add 0.15-0.25% Ca-Si alloy, of which the mass percentage of Ca is 25%. Ca reacts with O in the melt to form CaO, the reaction formula is 2Ca+O2→2CaO, and the purification is completed by keeping the temperature for 18-22 min.

[0011] S3. Gradient quenching: the purified melt is sprayed out through a nozzle with a diameter of 0.9-1.1 mm, and the nozzle is made of zirconia ceramic. The melt impacts a chromium-zirconium-copper roller at a speed of 35-40 m / s, and the rotation speed of the copper roller is set to 3200-3800 r / min. The copper roller is provided with two temperature zones along the radial direction, which are 25-40℃ and 15-25℃ respectively, and the temperature difference is maintained at 8-12℃ by an independent temperature control system. The distance between the nozzle and the surface of the copper roller is controlled at 0.25-0.35 mm.

[0012] S4. Subsection annealing: the quenched strip is placed in a vacuum annealing furnace, vacuumed to -0.096 to -0.098 MPa. The temperature is raised to 380-420℃ at a rate of 6-8℃ / min, and held for 40-50 min. Then the temperature is lowered to 300-320℃ at a rate of 2-3℃ / min, and held for 20-30 min. Finally, the heating device is turned off, and the furnace is cooled to room temperature.

[0013] Preferably, the present application further comprises S1.1 raw material pretreatment: Fe, Si, B particles are placed in a vacuum drying oven, dried at 120-150℃ for 2-3h. Zr, Sc are processed into wires with a diameter of 1-2mm, and La is processed into a sheet with a thickness of 0.5-1mm. The water content of the treated raw materials is controlled to be ≤0.05%, and impurity particles are removed by filtering through a 100 mesh screen before use.

[0014] Preferably, the present application further comprises S2.1 filtration after purification: after the melt purification is completed, filtration is performed through an alumina ceramic filter with a pore size of 50-80μm. The filter is preheated at 1200-1300℃ for 30min before use, and the melt temperature is maintained at not less than 1400℃ during the filtration process to prevent the melt from solidifying due to temperature drop during filtration.

[0015] Preferably, in the gradient quenching of S3 of the present application, circulating cooling water is introduced into the copper roller, and the water flow rate is controlled at 1.5-2m / s. The surface roughness of the copper roller is controlled at Ra≤0.5μm, and the surface runout amount during operation is ≤0.01mm, ensuring uniform thickness of the strip.

[0016] Preferably, in S3 of the present application, a ring-shaped gas injection device is provided at the outlet of the nozzle to inject nitrogen gas with a purity of 99.9% into the melt. The gas flow rate is controlled at 18-22L / min, and the gas temperature is controlled at 5-10℃, further increasing the cooling rate of the melt through gas-assisted cooling.

[0017] Preferably, in S4 of the present application, before subsection annealing, the strip is fixed with a graphite clamp. The part of the clamp in contact with the strip is pre-coated with a 0.1-0.2mm thick boron nitride coating, and the coating is dried before use. The clamping tension of the strip is controlled at 5-8N to prevent deformation of the strip during annealing.

[0018] Preferably, the present application further comprises S5. Surface passivation: the annealed strip is placed in a container containing a silane coupling agent KH-550 ethanol solution, and the mass fraction of silane coupling agent in the solution is 0.8-1.2%. The strip is completely immersed in the solution, soaked at room temperature for 10-15min, and then naturally air-dried to form a passivation film on the surface.

[0019] Preferably, the S5 of the present application is followed by ultrasonic cleaning: the passivated strip is placed in an ultrasonic cleaning tank, deionized water is added to the tank, and the water temperature is controlled at 40-50℃. The ultrasonic frequency is set to 45-55 kHz, and the treatment time is 8-12 min. After cleaning, the strip is placed in an oven and dried at 60-70℃ for 30-40 min.

[0020] Preferably, the amorphous strip prepared by the present application has a thickness of 25-35 μm and a width of 60-90 mm. The strip has a saturation magnetic induction ≥1.85 T and an amorphous formation critical cooling rate ≤10 4 K / s, and a magnetic permeability at room temperature ≥1.2×10 4 H / m.

[0021] (Three) Beneficial technical effects Compared with the existing technology, the beneficial effects of the present application are: At the component design level, a "Fe-Si-B-Nb-Cu + multi-rare earth" composite system is adopted, and Y, Sc, Zr, and La (or Ce) and other rare earth elements are introduced to work synergistically. The rare earth elements react with B to form stable rare earth borides, which not only avoid the oxidation segregation of rare earth elements, but also refine the melt structure, inhibit heterogeneous nucleation, and effectively retain the high saturation magnetic induction of the strip while enhancing the amorphous formation ability, successfully achieving the balance between "high formation ability" and "high magnetic performance".

[0022] At the melt purification link, a combined process of "argon protection + Ca-Si alloy deoxidization + ceramic filter filtration" is used to achieve deep melt purification. Ca reacts with oxygen to form stable CaO, which is combined with high-temperature ceramic filters to remove small inclusions, significantly reducing the heterogeneous nucleation points of amorphous formation and significantly reducing the critical cooling rate of amorphous formation, thereby improving the stability of amorphous formation from the source.

[0023] In the rapid solidification process, the combination of gradient double-temperature zone copper roller and low-temperature nitrogen assisted cooling realizes the uniform and controllable cooling rate. The double-temperature zone design of the copper roller solves the cooling difference problem between the edge and center of the strip, avoiding edge crystallization; the low-temperature nitrogen further improves the cooling efficiency, ensuring that the melt quickly passes through the crystallization temperature range, significantly reducing the risk of strip crystallization, and improving the thickness uniformity of the strip.

[0024] The segmented annealing process precisely matches the relaxation rules of amorphous atoms, first promotes atomic ordering relaxation through high-temperature holding, and then eliminates internal stress through low-temperature holding, effectively optimizing the uniformity of the strip's magnetic permeability and mechanical properties, and avoiding the performance fluctuations caused by traditional constant temperature annealing. After annealing, the surface passivation treatment forms a dense protective film on the surface of the strip, significantly improving its oxidation resistance and corrosion resistance, and prolonging the service life of the strip.

[0025] In addition, the whole-process process synergistic design from raw material pretreatment to surface passivation ensures the parameter matching of each link, greatly improves the qualified rate of strip production and the performance consistency, and reduces the cost of large-scale production. In summary, the process not only effectively enhances the amorphous forming ability, but also synchronously optimizes the magnetic performance, mechanical performance and stability of the strip, and provides reliable technical support for large-scale and high-quality production of high-saturation magnetic amorphous strip. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 is a flow chart of the amorphous forming ability enhancement method of the high-saturation magnetic amorphous strip according to the present application; Fig. 2 is a critical cooling rate column chart of different samples of the embodiment and the comparative example of the present application; Fig. 3 is a rust area fold line chart of different samples of the embodiment and the comparative example of the present application after 500h salt spray test; Fig. 4 is a combination column chart of tensile strength and Vickers hardness of different samples of the present application. DETAILED DESCRIPTION

[0027] According to Figs. 1 to 4 , the specific embodiments of the present application are as follows: Example 1

[0028] Raw material preparation The raw material components are Fe80%, Si4%, B7%, Nb1.5%, Cu0.7%, Y0.35%, Sc0.2%, Zr0.1%, and La0.05% by atomic percentage. The purity of Fe is 99.95%, the purity of Si is 99.9%, the purity of B is 99.5%, and the purity of the remaining elements is all 99.9%.

[0029] Pretreatment: put the Fe, Si and B particles into a vacuum drying oven, dry at 135℃ for 2.5h, and control the moisture content to 0.03%. Zr and Sc are processed into 1.5mm diameter wires, and La is processed into 0.8mm thick sheets. All raw materials are filtered through a 100 mesh screen.

[0030] Preparation process S1. Raw material preparation: put the pretreated raw materials into a vacuum melting furnace, vacuumize to-0.098MPa, and heat to 1580℃. When melting for 30min, La reacts with B to form LaB6, the reaction formula is La+6B→LaB6, and continue to heat for 38min to obtain a uniform master alloy ingot.

[0031] S1.1 Raw material mixing: use a planetary ball mill, rotate at 400r / min, ball-to-material ratio is 5:1, mix for 3h to ensure uniform distribution of raw materials.

[0032] S2. Melt purification: the master alloy ingot was put into an induction heating furnace, remelted at 1480℃, and then purified by blowing argon gas with a purity of 99.999% at a flow rate of 9L / min, and adding 0.2% Ca-Si alloy with a mass ratio of Ca of 25%. Ca reacts with O to form CaO, and the reaction formula is 2Ca + O2→ 2CaO. The purification was completed after 20 min of holding.

[0033] S2.1 Filtration after purification: the melt was filtered through an alumina ceramic filter with a pore size of 65μm. The filter was preheated at 1250℃ for 30 min. The melt temperature was maintained at 1420℃ during the filtration process to avoid solidification.

[0034] S3. Gradient quenching: the purified melt was sprayed through a zirconia ceramic nozzle with a diameter of 1.0mm at a speed of 38m / s, and impacted a chromium-zirconium-copper roller. The copper roller rotated at a speed of 3500r / min, and was provided with a double temperature zone along the radial direction, with an outer layer temperature of 32℃ and an inner layer temperature of 20℃, and a temperature difference of 10℃. The surface roughness of the copper roller was Ra0.4μm, and the surface runout was 0.008mm during operation. The distance between the nozzle and the surface of the copper roller was 0.3mm. An annular device at the outlet of the nozzle sprayed nitrogen gas with a purity of 99.9% at a flow rate of 20L / min, and a gas temperature of 8℃ for auxiliary cooling.

[0035] S4. Sectional annealing: the strip was fixed with a graphite clamp, and the contact part between the clamp and the strip was coated with a 0.15mm thick boron nitride coating. The strip was clamped with a tension force of 6.5N. The strip was placed in a vacuum annealing furnace, and the vacuum was extracted to -0.097MPa. The temperature was raised to 400℃ at a rate of 7℃ / min, and held for 45min. The temperature was then lowered to 310℃ at a rate of 2.5℃ / min, and held for 25min. Finally, the furnace was cooled to room temperature.

[0036] S5. Surface passivation: the annealed strip was immersed in an ethanol solution containing 1.0% silane coupling agent KH-550 at room temperature for 12min, and then naturally air-dried. A passivation film was formed on the surface.

[0037] S5.1 Ultrasonic cleaning: the passivated strip was placed in deionized water at 40℃, and treated with ultrasonic frequency of 50kHz for 10min. Then, the strip was placed in an oven at 70℃ for drying for 35min.

[0038] Performance detection The prepared amorphous strip had a thickness of 30μm and a width of 75mm. The saturation magnetic induction was 1.88T, the amorphous formation critical cooling rate was 8×10 3 K / s, and the room temperature permeability was 1.3×10 4 H / m. The strip passed the 500h salt spray test without rusting, and had good mechanical property uniformity. Example 2

[0039] Raw material preparation Raw material ingredients: Fe 79%, Si 4.5%, B 7.5%, Nb 1.2%, Cu 0.6%, Y 0.3%, Sc 0.15%, Zr 0.08%, La 0.03% by atomic percentage. Fe purity 99.95%, Si purity 99.9%, B purity 99.5%, and the purity of the remaining elements is 99.9%.

[0040] Pre-treatment: Put Fe, Si, and B particles into a vacuum drying oven and dry at 120°C for 3h, with a moisture content of 0.04%. Zr and Sc are processed into 1mm diameter wires, and La is processed into 0.5mm thick sheets. All raw materials are filtered through a 100 mesh screen.

[0041] Preparation process S1. Raw material preparation: Put the pre-treated raw materials into a vacuum melting furnace, vacuum to -0.098MPa, and heat to 1550°C. During the melting process, La reacts with B to form LaB6, the reaction formula is La + 6B → LaB6, and a uniform master alloy ingot is obtained after 35min of holding.

[0042] S1.1 Raw material mixing: Use a planetary ball mill at a speed of 300r / min, ball-to-material ratio of 5:1, and mix for 2h to ensure uniform distribution of the raw materials.

[0043] S2. Melt purification: Put the master alloy ingot into an induction heating furnace, remelt at 1450°C, and then introduce 99.999% pure argon gas at a flow rate of 8L / min. Add 0.15% Ca-Si alloy, with Ca mass fraction of 25%. Ca reacts with O to form CaO, the reaction formula is 2Ca + O2 → 2CaO, and the purification is completed after 18min of holding.

[0044] S2.1 Filtration after purification: The melt passes through an alumina ceramic filter with a pore size of 50μm. The filter is preheated at 1200°C for 30min, and the melt temperature is maintained at 1410°C during filtration to avoid solidification.

[0045] S3. Gradient rapid cooling: The purified melt is sprayed through a zirconia ceramic nozzle with a diameter of 0.9mm at a speed of 35m / s, impacting a chromium-zirconium-copper roller. The copper roller rotates at 3200r / min, with a double temperature zone along the radial direction, the outer layer temperature is 25°C, the inner layer temperature is 15°C, and the temperature difference is 10°C. The surface roughness of the copper roller is Ra0.5μm, and the surface runout is 0.009mm during operation. The distance between the nozzle and the surface of the copper roller is 0.25mm, and the annular device at the outlet of the nozzle sprays 99.9% pure nitrogen gas at a flow rate of 18L / min, with a gas temperature of 5°C for auxiliary cooling.

[0046] S4. Segment annealing: The strip is fixed with graphite clamp, the contact part of the clamp and the strip is coated with 0.1mm thick boron nitride coating, and the strip tension is controlled to be 5N during clamping. The strip is placed in a vacuum annealing furnace, vacuumed to -0.096MPa, heated to 380℃ at a rate of 6℃ / min, kept for 40min, then cooled to 300℃ at a rate of 2℃ / min, kept for 20min, and finally cooled to room temperature with the furnace.

[0047] S5. Surface passivation: The annealed strip is placed in an ethanol solution containing 0.8% silane coupling agent KH-550, soaked at room temperature for 10min, and then naturally air-dried to form a passivation film on the surface.

[0048] S5.1 Ultrasonic cleaning: The passivated strip is placed in deionized water at 40℃, set the ultrasonic frequency to 45kHz, and treated for 8min, then placed in an oven at 60℃ for drying for 30min.

[0049] Performance test The prepared amorphous strip has a thickness of 25μm and a width of 60mm. The saturation magnetic induction is 1.86T, the amorphous formation critical cooling rate is 9×10 3 K / s, and the room temperature permeability is 1.25×10 4 H / m. After 500h salt spray test, only slight discoloration occurs, and the mechanical property uniformity is good. Example 3

[0050] Raw material preparation The raw material ingredients are: Fe 81%, Si 3.5%, B 6.5%, Nb 1.8%, Cu 0.9%, Y 0.4%, Sc 0.25%, Zr 0.12%, and Ce 0.03% in atomic percentage. The purity of Fe is 99.95%, the purity of Si is 99.9%, the purity of B is 99.5%, and the purity of the remaining elements is all 99.9%.

[0051] Pre-treatment: The Fe, Si, and B particles are placed in a vacuum drying oven and dried at 150℃ for 2h, with the water content controlled to 0.02%. Zr and Sc are processed into 2mm diameter wires, and Ce is processed into 1mm thick sheets. All raw materials are filtered through a 100 mesh screen.

[0052] Preparation process S1. Raw material preparation: The pre-treated raw materials are placed in a vacuum melting furnace, vacuumed to -0.098MPa, and heated to 1600℃. During the melting process, Ce reacts with B to form CeB6, the reaction formula is Ce + 6B → CeB6, and the uniform master alloy ingot is prepared by keeping for 40min.

[0053] S1.1 Raw material mixing: A planetary ball mill is used, the rotation speed is 500r / min, the ball-to-material ratio is 5:1, and the mixing time is 4h to ensure uniform distribution of the raw materials.

[0054] S2. Melt purification: The master alloy ingot was put into an induction heating furnace and remelted at 1500°C. Then, argon gas with a purity of 99.999% was introduced at a flow rate of 10 L / min, and 0.25% Ca-Si alloy was added, in which the mass fraction of Ca was 25%. Ca reacted with O to form CaO, and the reaction equation was 2Ca + O2→ 2CaO. The purification was completed after 22 min of holding.

[0055] S2.1 Filtration after purification: The melt passed through an alumina ceramic filter with a pore size of 80 μm. The filter was preheated at 1300°C for 30 min. The melt temperature was maintained at 1430°C during the filtration process to avoid solidification.

[0056] S3. Gradient quenching: The purified melt was sprayed through a zirconia ceramic nozzle with a diameter of 1.1 mm at a speed of 40 m / s, and impacted a chromium-zirconium-copper roller. The roller rotated at a speed of 3800 r / min, and was provided with a double temperature zone along the radial direction, with an outer layer temperature of 40°C and an inner layer temperature of 25°C, and a temperature difference of 15°C. The surface roughness of the copper roller was Ra 0.3 μm, and the surface run-out amount was 0.007 mm during operation. The distance between the nozzle and the surface of the copper roller was 0.35 mm. An annular device at the outlet of the nozzle sprayed nitrogen gas with a purity of 99.9% at a flow rate of 22 L / min and a gas temperature of 10°C for auxiliary cooling.

[0057] S4. Sectional annealing: The strip was fixed with a graphite clamp, and the contact part between the clamp and the strip was coated with a 0.2 mm thick boron nitride coating. The strip was clamped with a tension force of 8 N. The strip was placed in a vacuum annealing furnace, and the vacuum was extracted to -0.098 MPa. The temperature was raised to 420°C at a rate of 8°C / min, held for 50 min, then lowered to 320°C at a rate of 3°C / min, held for 30 min, and finally cooled to room temperature with the furnace.

[0058] S5. Surface passivation: The annealed strip was immersed in an ethanol solution containing 1.2% silane coupling agent KH-550 at room temperature for 15 min, and then naturally air-dried. A passivation film was formed on the surface.

[0059] S5.1 Ultrasonic cleaning: The passivated strip was placed in deionized water at 50°C, and treated with ultrasonic frequency of 55 kHz for 12 min, and then dried in an oven at 70°C for 40 min.

[0060] Performance testing The prepared amorphous strip had a thickness of 35 μm and a width of 90 mm. The saturation magnetic induction was 1.90 T, the amorphous formation critical cooling rate was 7×10 3 K / s, and the room temperature permeability was 1.35×10 4 H / m. No rust was observed after 500 h of salt spray testing, and the mechanical property uniformity was excellent.

[0061] Comparative Example Raw material preparation Raw material ingredients: Fe 82%, Si 5%, B 8%, Nb 1%, Cu 0.5% by atomic percentage, without rare earth element addition. Fe purity 99.9%, Si purity 99.8%, B purity 99.0%, and the purity of the remaining elements is 99.5%.

[0062] Pretreatment: The raw materials were not dried and sieved, and were directly used, with a moisture content of 0.15%.

[0063] Preparation process S1. Raw material preparation: The raw materials were directly mixed and then placed in a common smelting furnace, and were smelted at 1500°C under non-vacuum conditions for 30 min to obtain a master alloy ingot, without rare earth element reaction process.

[0064] S1.1 Raw material mixing: The raw materials were mixed by common stirring at a speed of 200 r / min for 1 h.

[0065] S2. Melt purification: After remelting the master alloy ingot at 1400°C, only 99.9% pure argon was introduced at a flow rate of 5 L / min, without adding Ca-Si alloy, and the temperature was maintained for 15 min, without purification reaction.

[0066] S2.1 Filtration after purification: No filtration treatment was performed, and the melt was directly subjected to the rapid cooling process.

[0067] S3. Rapid cooling treatment: The melt was sprayed out through a common ceramic nozzle with a diameter of 1.2 mm at a speed of 30 m / s, and impacted a single-zone copper roller (temperature 25°C). The copper roller rotated at a speed of 2800 r / min, with a surface roughness of Ra 1.0 μm, and the nozzle was 0.5 mm away from the roller surface, without nitrogen assisted cooling.

[0068] S4. Annealing treatment: The strip was fixed using a common metal clamp, without coating protection, and was placed in an annealing furnace at 350°C for constant temperature annealing for 60 min in a non-vacuum environment, and was naturally cooled.

[0069] S5. Surface treatment: No passivation treatment was performed, and only water washing was performed followed by natural air drying.

[0070] Performance detection The prepared strip had uneven thickness in the range of 20-40 μm and width of 50-80 mm. Partial crystallization occurred, and the amorphous phase ratio was 75%. The saturation magnetic induction was 1.70 T, the critical cooling rate for amorphous formation was 2×10 4 K / s, and the room temperature permeability was 0.8×10 4 H / m. After 100 h of salt spray testing, large area rusting occurred, and the mechanical properties were not uniform.

[0071] Performance comparison table Table 1: Amorphous forming ability and magnetic performance parameters

[0072] The table quantifies the differences between the process and the traditional process from the core performance dimension. Examples 1-3 add multiple rare earths and generate stable borides through reaction, and the amorphous phase ratio is 100%, the critical cooling rate is as low as 7x10 3 -9x10 3 K / s, significantly reducing the difficulty of amorphous formation; at the same time, precise control of rare earth content, saturation magnetic induction remains 1.86-1.90T, permeability reaches 1.25x10 4 -1.35x10 4 H / m. The comparative example has no rare earth optimization and the process is rough, the amorphous phase ratio is only 75%, the critical cooling rate is as high as 2x10 4 K / s, the saturation magnetic induction and permeability decrease significantly, which directly proves that the composition design and process synergy is the key to improving the amorphous forming ability and magnetic performance.

[0073] Table 2: Strip quality and corrosion resistance indicators

[0074] This table focuses on strip production quality and durability in use. Examples 1-3 control the gradient quenching and precise positioning with tooling, the thickness deviation is only ±0.8-1.2μm, the surface roughness Ra is 0.3-0.5μm, and the quality uniformity is excellent; the passivation treatment after annealing makes the 500h salt spray test have no obvious rust, and the mechanical property uniformity is over 97%. The comparative example has uneven cooling and no surface protection, the thickness deviation is ±5μm, the surface is rough and rusts in large area within 100h, and the mechanical uniformity is only 82%, highlighting the advancement of the present forming control and corrosion protection process, ensuring the subsequent processing and long-term use performance of the strip.

[0075] Table 3: Comparison of thermal stability and mechanical properties

[0076] This table evaluates the stability and mechanical reliability of the strip in high temperature environment. Examples 1-3 benefit from multiple rare earth strengthening and segmented annealing to eliminate internal stress, the thermal weight loss rate is only 0.7-0.9% at 500℃, the Vickers hardness is 510-530HV, the tensile strength is 1800-1900MPa, and the elongation at break is 2.0-2.3%, with high thermal stability and good mechanical properties. The comparative example has a single composition and concentrated internal stress, the thermal weight loss rate is 2.5%, the hardness and tensile strength are greatly reduced, and the elongation is only 1.1%, which is prone to failure in high temperature or stressed working conditions, proving that the present process can simultaneously improve the thermal stability and mechanical properties of the strip.

[0077] Table 4: Comparison of magnetic loss and process stability

[0078] This table analyzes the energy efficiency and scalability of the strip. Examples 1-3 have uniform amorphous structure, small internal stress, and significantly lower magnetic loss at 50Hz and 1kHz than the comparative examples, with obvious energy efficiency advantages; the full-process collaborative design makes the batch production qualified rate exceed 98.8%, with a width deviation of only ±0.2-0.4mm, excellent consistency. The comparative examples have high magnetic loss due to mismatched process parameters and lack of quality control, with a qualified rate of only 78.5% and a width deviation of ±1.5mm, making it difficult to meet the needs of large-scale production, reflecting the dual advantages of energy efficiency and production stability of the present process.

[0079] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon, characterized in that: The following steps are involved: S1. Raw material preparation: Fe79-81%, Si3.5-4.5%, B6.5-7.5%, Nb1.2-1.8%, Cu0.6-0.9% were weighed by atomic percentage, 0.3-0.4% Y, 0.15-0.25% Sc, 0.08-0.12% Zr were added, and 0.03-0.06% La was added. The above raw materials were mixed and smelted in a vacuum melting furnace. During the smelting process, La reacted with B to form LaB6. The master alloy ingot was obtained by holding for 35-40min. S2. Melt purification: Place the master alloy ingot in an induction heating furnace and heat it to 1450-1500°C for remelting. Argon is introduced into the furnace, and 0.15-0.25% Ca-Si alloy is added, with Ca accounting for 25% by weight. The Ca reacts with the O in the melt to form CaO. The furnace is kept at this temperature for 18-22 minutes to complete the purification. S3. Gradient quenching: The purified melt is ejected through a zirconia ceramic nozzle with a diameter of 0.9-1.1 mm. The melt impacts a chromium-zirconium-copper roller at a velocity of 35-40 m / s. The roller is radially divided into two temperature zones: 25-40°C and 15-25°C. An independent temperature control system maintains a temperature difference of 8-12°C. S4. Segmented Annealing: Place the rapidly cooled strip into a vacuum annealing furnace, evacuate the vacuum, and heat to 380-420°C. Then cool it to 300-320°C and hold for 20-30 minutes. Finally, turn off the heating device and allow the strip to cool to room temperature.

2. The method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon according to claim 1, characterized in that: It also includes S1.1 raw material pretreatment: Fe, Si, and B particles are placed in a vacuum drying oven and dried at 120-150°C for 2-3 hours. Zr and Sc are processed into wires with a diameter of 1-2 mm, and La is processed into thin sheets with a thickness of 0.5-1 mm. The moisture content of the processed raw materials is controlled at ≤0.05%, and impurity particles are removed by filtering through a 100-mesh sieve before use.

3. The method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon according to claim 1, characterized in that: It also includes S2.1 post-purification filtration: After the melt is purified, it is filtered through an alumina ceramic filter with a pore size of 50-80μm. The filter is preheated at 1200-1300℃ for 30 minutes before use. The melt temperature is maintained at not less than 1400℃ during the filtration process.

4. The method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon according to claim 1, characterized in that: During the gradient rapid cooling in S3, circulating cooling water is introduced into the copper roller, and the water flow rate is controlled at 1.5-2m / s. The surface roughness of the copper roller is controlled at Ra≤0.5μm, and the surface runout during operation is ≤0.01mm.

5. The method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon according to claim 1, characterized in that: In S3, an annular gas injection device is set at the nozzle outlet to spray nitrogen with a purity of 99.9% to the melt. The gas flow rate is controlled at 18-22 L / min and the gas temperature is controlled at 5-10°C.

6. The method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon according to claim 1, characterized in that: Before the segmented annealing in S4, the strip is fixed with a graphite clamp. The contact area between the clamp and the strip is pre-coated with a 0.1-0.2mm thick boron nitride coating. The coating is used after it dries. The tension of the strip is controlled at 5-8N during clamping.

7. The method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon according to claim 1, characterized in that: Also included is S5. Surface passivation: the annealed strip is placed in a container containing a silane coupling agent KH-550 ethanol solution, where the mass fraction of the silane coupling agent in the solution is 0.8-1.2%. The strip is completely immersed in the solution for 10-15 minutes at room temperature, and then taken out and naturally dried to form a passivation film on the surface.

8. The method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon according to claim 7, characterized in that: Ultrasonic cleaning is performed after S5: the passivated strip is placed in an ultrasonic cleaning tank, deionized water is added to the tank, the water temperature is controlled at 40-50°C, the ultrasonic frequency is set to 45-55kHz, and the processing time is 8-12 minutes. After cleaning, the strip is placed in an oven and dried at 60-70°C for 30-40 minutes.

9. The method for enhancing the amorphous forming ability of a high saturation magnetic induction amorphous ribbon according to claim 1, characterized in that: The thickness of the prepared amorphous strip is controlled at 25-35 μm, the width is controlled at 60-90 mm, the saturation magnetic induction of the strip is ≥1.85 T, and the critical cooling rate of amorphous formation is ≤10 4 K / s, magnetic permeability at room temperature ≥1.2×10 4 H / m.

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