Iron-based amorphous magnetically soft alloy cast strip and preparation method thereof

Abstract

The invention relates to the technical field of magnetically soft alloys, and particularly discloses an iron-based amorphous magnetically soft alloy cast strip and a preparation method thereof. The chemical expression of the alloy cast strip is FeaCobBcSidCeNbfCugSmhVi, and a, b, c, d, e, f, g, h and i respectively represent the atomic percentage contents of corresponding chemical components; wherein a is equal to 68-72, b is equal to 11-15, c is equal to 6-7.5, d is equal to 5.5-7.1, e is equal to 0.3-0.5, f is equal to 1.2-2, g is equal to 0.4-1.5, h is equal to 0.3-1, i is equal to 0.1-0.5, and a + b + c + d + e + f + g + h + i is equal to 100. The alloy cast strip with excellent comprehensive performance is obtained by controlling the chemical components and the atomic ratio of the alloy cast strip, utilizing the influence of different alloy systems and chemical elements on the performance of the alloy cast strip and comprehensively considering the thermodynamic and dynamic conditions of amorphous formation.

Description

Technical Field

[0001] The invention relates to the technical field of soft magnetic alloys, and in particular to an iron-based amorphous soft magnetic alloy casting strip and a preparation method thereof. Background Art

[0002] Iron-based amorphous nanocrystalline soft magnetic alloys have the characteristics of high saturation magnetic induction, low coercive force, high magnetic permeability and low loss, and the preparation process is simple, the manufacturing cost is low, and they can be recycled and reused. They are known as energy-saving and environmentally friendly functional device materials in the 21st century and are widely used in technical fields such as transformers, servo motors and sensors. In response to the market requirements for high efficiency and miniaturization of devices, further improving the saturation magnetic induction of amorphous nanocrystalline soft magnetic alloys has become one of the problems that need to be solved urgently. Summary of the invention

[0003] In view of the above problems, the present invention provides an iron-based amorphous soft magnetic alloy casting strip and a preparation method thereof. By controlling the chemical composition and atomic ratio of the iron-based amorphous soft magnetic alloy casting strip, the saturation magnetic induction intensity and magnetic permeability of the iron-based amorphous soft magnetic alloy casting strip are significantly improved, while the coercive force and loss are reduced.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is: In a first aspect, the present invention provides an iron-based amorphous soft magnetic alloy casting strip, the chemical formula of which is Fe a Co b B c Si d C e Nb f Cu g Sm h V i , a, b, c, d, e, f, g, h and i represent the atomic percentages of the corresponding chemical components; Among them, a=68~72, b=11~15, c=6~7.5, d=5.5~7.1, e=0.3~0.5, f=1.2~2, g=0.4~1.5, h=0.3~1, i=0.1~0.5, and a+b+c+d+e+f+g+h+i=100.

[0005] Compared with the prior art, the iron-based amorphous soft magnetic alloy casting strip (alloy casting strip for short) provided by the present invention adopts strong magnetic elements Fe and Co to provide a net magnetic moment for the alloy casting strip, thereby ensuring its high saturation magnetic induction intensity; the metalloid elements B, Si and C play a role in improving the amorphous forming ability, the B element is a strong amorphous forming element, which can improve the glass forming ability of the alloy, and it is very easy to form an oxide B2O3 with a low melting point during the smelting process, resulting in an increase in the viscosity of the melt, a decrease in the fluidity, and an increase in the difficulty of amorphous formation. Therefore, under the premise of ensuring the performance and glass forming ability of the alloy casting strip, the fluidity of the melt can be regulated by adjusting the addition ratio of the B element; the Si element, as an essential metalloid element, can improve the glass forming ability, help to improve the cleanliness of the melt, increase the stability of the melt, reduce the magnetostriction coefficient, promote the continuous production of the alloy casting strip, and improve its soft magnetic properties; the main components Fe, Co, B and Si elements in the alloy have a hysteresis diffusion effect, which can effectively inhibit the excessive growth of α-Fe type soft magnetic phase grains during heat treatment, reduce the coercive force of nanocrystals, and improve the soft magnetic properties.

[0006] Nb, an element with a large atomic size, is not only conducive to the improvement of amorphous forming ability, but also can inhibit the excessive growth of α-Fe soft magnetic phase grains during heat treatment; Cu is immiscible with Fe and Co, and can be used as a heterogeneous nucleation point to promote the nucleation of α-Fe soft magnetic phase; Sm, as a rare earth element, has a certain paramagnetism, which can purify the purity of the melt, reduce the oxygen content, greatly improve the glass forming ability of the alloy casting strip, and also help to improve the intensity of the ferromagnetic interaction between ferromagnetic elements; In addition, Sm has a high oxygen affinity and a very strong binding force for oxygen. It can be used as a purifier during the smelting process to avoid the formation of oxides that deteriorate magnetic properties and glass forming ability with component elements, and eliminate the adverse effects of oxygen on the alloy casting strip; V is a common transition metal element, and its addition can improve the glass forming ability of the alloy casting strip, and its larger atomic radius can effectively inhibit the growth of grains during the crystallization of the alloy, and obtain a crystalline structure with fine grains. It also has a strong oxygen affinity, which can purify the melt during the smelting process and improve the melt fluidity.

[0007] However, in order to avoid deteriorating the soft magnetic properties of the alloy strip while improving the glass-forming ability of the alloy strip, the large addition of non-magnetic transition metal elements (Nb, Cu, Sm and V) should be avoided. The addition of Sm will significantly increase the cost of raw materials, reduce the saturation magnetic induction and magnetic permeability of the alloy strip, and increase its coercive force and room temperature brittleness; when the V content exceeds 1at%, not only the cost increases, but also its saturation magnetic induction and bending toughness are significantly reduced.

[0008] In the process of designing the chemical composition and content of the iron-based amorphous soft magnetic alloy casting strip, the present invention fully understands the influence of different alloy systems and chemical elements on the performance of the alloy casting strip, comprehensively considers the thermodynamic and kinetic conditions of amorphous formation, combines the deep eutectic theory and dense cluster stacking structure of amorphous alloy design, and obtains an iron-based amorphous soft magnetic alloy casting strip with excellent comprehensive performance, which has a high market application value.

[0009] Preferably, a+b=83.

[0010] In the present invention, the higher content of Fe and Co elements in the alloy casting strip ensures that it has a higher saturation magnetic induction intensity and excellent soft magnetic properties; the specific ratio of Co element and Fe element has a larger ferromagnetic interaction intensity, which can improve the saturation magnetic induction intensity of the iron-based amorphous alloy.

[0011] Preferably, c+d+e=12~15.

[0012] Preferably, c:d:e=(48~52):(45~50):3.

[0013] In the present invention, the metalloid elements and the Fe element have a large difference in mixing enthalpy and atomic radius, and appropriate addition is helpful to improve the glass forming ability of the alloy casting strip. When the content of the metalloid elements in the alloy casting strip is less than 12at%, it is difficult to prepare the iron-based amorphous alloy casting strip; when the content of the metalloid elements exceeds 15at%, the soft magnetic properties and bending toughness of the iron-based amorphous alloy casting strip will be slightly deteriorated.

[0014] Preferably, the iron-based amorphous soft magnetic alloy casting strip has a thickness of 5 μm to 16 μm and a width of 120 mm to 220 mm. Further preferably, the iron-based amorphous soft magnetic alloy casting strip has a thickness of 8 μm to 15 μm and a width of 140 mm to 180 mm.

[0015] The iron-based amorphous soft magnetic alloy casting strip provided by the invention has the characteristics of large size and high saturation magnetic induction intensity.

[0016] In a second aspect, the present invention provides a method for preparing an iron-based amorphous soft magnetic alloy casting strip, comprising the following steps: S1, weighing alloy raw materials according to the atomic percentage of chemical components, and performing vacuum induction melting and casting on the alloy raw materials under a protective atmosphere to obtain a master alloy ingot; S2, in a protective atmosphere, subjecting the master alloy ingot to vacuum induction remelting to obtain a remelted metal liquid; S3, using a twin-roll casting method to spray the remelted metal liquid onto the surface of a copper roll to obtain an alloy strip; S4, subjecting the alloy strip to longitudinal magnetic field heat treatment at 320°C-350°C, and then to first cooling; and then to annealing at 480°C-550°C, and then to second cooling, to obtain an iron-based amorphous soft magnetic alloy casting strip.

[0017] The preparation method of the iron-based amorphous soft magnetic alloy casting strip provided by the present invention adopts a step-by-step heat treatment method, firstly performing a longitudinal magnetic field heat treatment, thereby reducing the coercive force and saturation magnetostriction coefficient of the alloy strip, increasing the maximum magnetic permeability and remanence ratio, and making the hysteresis loop rectangular, thereby optimizing the grain size and increasing the saturation magnetic induction intensity; and then performing an annealing treatment, thereby effectively removing the stress of the alloy strip, achieving the optimization of magnetic properties, obtaining a more uniform amorphous structure, and increasing the yield of the alloy casting strip.

[0018] For example, in S1, the purity of the alloy raw material is ≥99.5wt%.

[0019] Preferably, the protective atmosphere is selected from nitrogen atmosphere, helium atmosphere or argon atmosphere.

[0020] Preferably, in S1, during the vacuum induction melting, the vacuum is first evacuated to a pressure of (6-9.5)×10 -3 Pa, and then introduce protective gas to a pressure of 60Pa~100Pa.

[0021] Preferably, in S1, the temperature of the vacuum induction melting is 1600° C. to 1800° C.; after the alloy raw material is melted, it is kept warm and stirred for 10 min to 20 min.

[0022] For example, in S1, after the pouring is completed, the process further includes: cooling to room temperature with the furnace, crushing, cleaning, and obtaining a master alloy ingot.

[0023] Preferably, in S2, during the vacuum induction remelting, the vacuum is first evacuated to a pressure of (6-9.5)×10 -3 Pa, and then introduce protective gas to a pressure of 60Pa~100Pa.

[0024] Preferably, in S2, the temperature of the vacuum induction remelting is 1400° C. to 1500° C.; after the master alloy ingot is melted, it is kept warm and stirred for 5 min to 8 min.

[0025] Preferably, in S3, the rolling force of the twin-roll casting method is 20 kN~40 kN.

[0026] Preferably, in S3, the linear speed of the copper roller surface is 1 m / s to 2 m / s.

[0027] For example, in S3, under a protective atmosphere, the remelted metal liquid is injected into a vertical twin-roll casting mill and then sprayed; the two copper rolls rotate in opposite directions.

[0028] Preferably, in S4, the magnetic field intensity of the longitudinal magnetic field heat treatment is 800Oe~1200Oe.

[0029] Preferably, in S4, the time of the longitudinal magnetic field heat treatment is 30 min to 40 min.

[0030] Preferably, in S4, the first cooling method is water quenching.

[0031] Preferably, in S4, the annealing time is 20 min to 30 min.

[0032] Preferably, in S4, the second cooling method is to cool the product to 300° C.-350° C. in the furnace and then air-cool the product out of the furnace.

[0033] The present invention can better control the uniform formation of amorphous materials by controlling the specific conditions in the above steps, and further improve the comprehensive performance of the alloy casting strip. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] In the present invention, unless otherwise specified, all materials are commercially available products.

[0036] Example 1 This embodiment provides an iron-based amorphous soft magnetic alloy casting strip Fe 70 Co 13 B7 6.58 C 0.42 Nb 1.5 Cu1Sm 0.4 V 0.1 .

[0037] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip comprises the following steps: S1, weigh the alloy raw materials (pure iron, industrial cobalt, ferroboron, silicon wafer, carbon powder, industrial ferroniobium, electrolytic copper, samarium powder and vanadium rod) according to the atomic percentage of chemical components, put the alloy raw materials into a vacuum induction furnace, and first evacuate the vacuum to a pressure of 8×10 - 3 Pa, and then nitrogen is introduced to a pressure of 80 Pa. Vacuum induction melting is carried out at 1700°C. After the alloy raw materials are completely melted, electromagnetic stirring is performed for 15 minutes. Then, casting is performed, and the alloy is cooled to room temperature with the furnace. Then, the alloy is crushed and cleaned to obtain a master alloy ingot.

[0038] S2, put the master alloy ingot into the vacuum induction furnace, first evacuate to the pressure of 7.5×10-3 Pa, and then nitrogen is introduced to a pressure of 80 Pa, and vacuum induction remelting is performed at 1450°C. After the mother alloy ingot is completely melted, electromagnetic stirring is performed for 7 minutes to obtain the remelted metal liquid.

[0039] S3, evacuate the vertical twin-roll casting machine to a pressure of 8×10 -3 Pa, and then nitrogen is introduced to a pressure slightly greater than the standard atmospheric pressure, and then the remelted metal liquid is sealed and injected into the above-mentioned vertical twin-roll casting and rolling mill, and the twin-roll casting method is adopted to spray it onto the surface of the counter-rotating copper roll (the linear speed is 1.5m / s), and the rolling force is 30kN to obtain the alloy strip.

[0040] S4, the alloy strip is subjected to longitudinal magnetic field heat treatment at 340°C and 1000Oe for 35 minutes, and water quenched to room temperature; then annealed at 520°C for 25 minutes, cooled to 320°C with the furnace, and then air-cooled to room temperature to obtain an iron-based amorphous soft magnetic alloy casting strip with a thickness of 12μm and a width of 160mm.

[0041] Example 2 This embodiment provides an iron-based amorphous soft magnetic alloy casting strip Fe 71 Co 12 B 6.5 Si 6.1 C 0.4 Nb2Cu 0.9 Sm 0.7 V 0.4 .

[0042] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip comprises the following steps: S1, weigh the alloy raw materials (pure iron, industrial cobalt, ferroboron, silicon wafer, carbon powder, industrial ferroniobium, electrolytic copper, samarium powder and vanadium rod) according to the atomic percentage of chemical components, put the alloy raw materials into a vacuum induction furnace, and first evacuate the vacuum to a pressure of 7×10 - 3 Pa, and then helium is introduced to a pressure of 70Pa, and vacuum induction melting is carried out at 1650℃. After the alloy raw materials are completely melted, electromagnetic stirring is performed for 18 minutes, and then pouring is performed. The alloy is cooled to room temperature with the furnace, and then crushed and cleaned to obtain a master alloy ingot.

[0043] S2, put the master alloy ingot into the vacuum induction furnace, first evacuate to the pressure of 7×10 -3 Pa, and then helium is introduced to a pressure of 70 Pa, and vacuum induction remelting is performed at 1430°C. After the mother alloy ingot is completely melted, electromagnetic stirring is performed for 7 minutes to obtain the remelted metal liquid.

[0044] S3, evacuate the vertical twin-roll casting machine to a pressure of 7×10 -3Pa, and then helium is introduced to a pressure slightly greater than the standard atmospheric pressure, and then the remelted metal liquid is sealed and injected into the above-mentioned vertical twin-roll casting and rolling mill, and the twin-roll casting method is adopted to spray it onto the surface of the counter-rotating copper roll (the linear speed is 1.2m / s), and the rolling force is 25kN to obtain the alloy strip.

[0045] S4, the alloy strip is subjected to longitudinal magnetic field heat treatment at 330°C and 1100Oe for 35 minutes, and water quenched to room temperature; then annealed at 500°C for 27 minutes, cooled to 330°C with the furnace, and then air-cooled to room temperature to obtain an iron-based amorphous soft magnetic alloy casting strip with a thickness of 10μm and a width of 150mm.

[0046] Example 3 This embodiment provides an iron-based amorphous soft magnetic alloy casting strip Fe 72 Co 11 B 7.5 Si 7.05 C 0.45 Nb 1.2 Cu 0.4 Sm 0.3 V0 .1 .

[0047] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip comprises the following steps: S1, weigh the alloy raw materials (pure iron, industrial cobalt, ferroboron, silicon wafer, carbon powder, industrial ferroniobium, electrolytic copper, samarium powder and vanadium rod) according to the atomic percentage of chemical components, put the alloy raw materials into a vacuum induction furnace, and first evacuate the vacuum to a pressure of 6×10 - 3 Pa, and then introduce argon to a gas pressure of 60Pa, and carry out vacuum induction melting at 1750℃. After the alloy raw materials are completely melted, electromagnetic stirring is carried out for 13 minutes, and then pouring is carried out. The alloy is cooled to room temperature with the furnace, crushed and cleaned to obtain the mother alloy ingot.

[0048] S2, put the master alloy ingot into the vacuum induction furnace, first evacuate the vacuum to the pressure of 6×10 -3 Pa, and then introduce argon gas to a pressure of 60Pa, and perform vacuum induction remelting at 1480℃. After the mother alloy ingot is completely melted, electromagnetic stirring is performed for 6min to obtain the remelted metal liquid.

[0049] S3, evacuate the vertical twin-roll casting machine to a pressure of 6×10 -3 Pa, and then argon gas is introduced to a pressure slightly greater than the standard atmospheric pressure, and then the remelted metal liquid is sealed and injected into the above-mentioned vertical twin-roll casting and rolling mill, and the twin-roll casting method is adopted to spray it onto the surface of the counter-rotating copper roll (the linear speed is 1.8m / s), and the rolling force is 34kN to obtain the alloy strip.

[0050] S4, the alloy strip is subjected to longitudinal magnetic field heat treatment at 320°C and 1200Oe for 40 minutes, and water quenched to room temperature; then annealed at 480°C for 30 minutes, cooled to 300°C with the furnace, and then air-cooled to room temperature to obtain an iron-based amorphous soft magnetic alloy casting strip with a thickness of 7μm and a width of 130mm.

[0051] Example 4 This embodiment provides an iron-based amorphous soft magnetic alloy casting strip Fe 69 Co 14 B6 5.65 C 0.35 Nb2Cu 1.5 Sm1 0.5 .

[0052] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip comprises the following steps: S1, weigh the alloy raw materials (pure iron, industrial cobalt, ferroboron, silicon wafer, carbon powder, industrial ferroniobium, electrolytic copper, samarium powder and vanadium rod) according to the atomic percentage of chemical components, put the alloy raw materials into a vacuum induction furnace, and first evacuate the vacuum to a pressure of 9×10 - 3 Pa, and then nitrogen is introduced to a pressure of 90Pa, and vacuum induction melting is carried out at 1600℃. After the alloy raw materials are completely melted, electromagnetic stirring is performed for 20 minutes, and then pouring is performed. The alloy is cooled to room temperature with the furnace, and then crushed and cleaned to obtain a mother alloy ingot.

[0053] S2, put the master alloy ingot into the vacuum induction furnace, first evacuate to the pressure of 9×10 -3 Pa, and then nitrogen is introduced to a pressure of 90 Pa, and vacuum induction remelting is performed at 1400°C. After the mother alloy ingot is completely melted, electromagnetic stirring is performed for 8 minutes to obtain the remelted metal liquid.

[0054] S3, the vertical twin-roll casting mill is evacuated to a pressure of 9×10 -3 Pa, and then nitrogen is introduced to a pressure slightly greater than the standard atmospheric pressure, and then the remelted metal liquid is sealed and injected into the above-mentioned vertical twin-roll casting and rolling mill, and the twin-roll casting method is adopted to spray it onto the surface of the counter-rotating copper roll (the linear speed is 1m / s) with a rolling force of 20kN to obtain an alloy strip.

[0055] S4, the alloy strip is subjected to longitudinal magnetic field heat treatment at 350°C and 800Oe for 30 minutes, and water quenched to room temperature; then annealed at 550°C for 20 minutes, cooled to 350°C with the furnace, and then air-cooled to room temperature to obtain an iron-based amorphous soft magnetic alloy casting strip with a thickness of 14μm and a width of 180mm.

[0056] Example 5 This embodiment provides an iron-based amorphous soft magnetic alloy casting strip Fe 68 Co15 B7 6.59 C 0.41 Nb 1.6 Cu 0.6 Sm 0.5 V 0.3 .

[0057] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip comprises the following steps: S1, weigh the alloy raw materials (pure iron, industrial cobalt, ferroboron, silicon wafer, carbon powder, industrial ferroniobium, electrolytic copper, samarium powder and vanadium rod) according to the atomic percentage of chemical components, put the alloy raw materials into a vacuum induction furnace, and first evacuate the vacuum to a pressure of 9.5×10 - 3 Pa, and then helium is introduced to a pressure of 100Pa, and vacuum induction melting is carried out at 1800℃. After the alloy raw materials are completely melted, electromagnetic stirring is performed for 10 minutes, and then pouring is performed. The alloy is cooled to room temperature with the furnace, crushed, cleaned, and a master alloy ingot is obtained.

[0058] S2, put the master alloy ingot into the vacuum induction furnace, first evacuate to the pressure of 9.5×10 -3 Pa, and then helium is introduced to a pressure of 100 Pa, and vacuum induction remelting is performed at 1500°C. After the mother alloy ingot is completely melted, electromagnetic stirring is performed for 5 minutes to obtain the remelted metal liquid.

[0059] S3, the vertical twin-roll casting mill is evacuated to a pressure of 9.5×10 -3 Pa, and then helium is introduced to a pressure slightly greater than the standard atmospheric pressure, and then the remelted metal liquid is sealed and injected into the above-mentioned vertical twin-roll casting and rolling mill, and the twin-roll casting method is adopted to spray it onto the surface of the counter-rotating copper roll (the linear speed is 2m / s), and the rolling force is 40kN to obtain the alloy strip.

[0060] S4, the alloy strip is subjected to longitudinal magnetic field heat treatment at 340°C and 900Oe for 35 minutes, and water quenched to room temperature; then annealed at 530°C for 23 minutes, cooled to 330°C with the furnace, and then air-cooled to room temperature to obtain an iron-based amorphous soft magnetic alloy casting strip with a thickness of 16μm and a width of 200mm.

[0061] The XRD patterns of the iron-based amorphous soft magnetic alloy casting strips provided in Examples 1 to 5 were tested. All the alloy casting strips had only one diffuse and broad diffraction peak, indicating that the alloy casting strips provided in Examples 1 to 5 were all of amorphous structure.

[0062] Comparative Example 1 This comparative example provides an iron-based amorphous soft magnetic alloy casting strip Fe 60 Co 23 B7 6.58 C 0.42 Nb 1.5Cu1Sm 0.4 V 0.1 .

[0063] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip is similar to that of Example 1, except that the atomic percentage of the chemical components is different. The remaining conditions are the same as those of Example 1 and will not be described in detail.

[0064] Comparative Example 2 This comparative example provides an iron-based amorphous soft magnetic alloy casting strip Fe 83 B7 6.58 C 0.42 Nb 1.5 Cu1Sm 0.4 V 0.1 .

[0065] The preparation method of the above-mentioned iron-based amorphous soft magnetic alloy casting strip is similar to that of Example 1, except that the atomic percentage of Fe is different and the addition of industrial cobalt is omitted. The remaining conditions are the same as those of Example 1 and will not be described in detail.

[0066] Comparative Example 3 This comparative example provides an iron-based amorphous soft magnetic alloy casting strip Fe 65 Co 10 B 11 Si 10.35 C 0.65 Nb 1.5 Cu1Sm 0.4 V 0.1 .

[0067] The preparation method of the above-mentioned iron-based amorphous soft magnetic alloy casting strip is similar to that of Example 1, except that the atomic percentages of the chemical components are different (the sum of the atomic percentages of the metalloid elements is 22 at%, and the sum of the atomic percentages of the Fe and Co elements is 75 at%). The remaining conditions are the same as those of Example 1 and will not be described in detail.

[0068] Comparative Example 4 This comparative example provides an iron-based amorphous soft magnetic alloy casting strip Fe 70 Co 13 B7 6.58 C 0.42 Nb 1.5 Cu1Nd 0.4 V 0.1 .

[0069] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip is similar to that in Example 1, except that the samarium powder in the alloy raw material is replaced by neodymium powder. The remaining conditions are the same as those in Example 1 and will not be described in detail.

[0070] Comparative Example 5 This comparative example provides an iron-based amorphous soft magnetic alloy casting strip Fe 70 Co 13 B7 6.58 C 0.42 Nb 1.5 Cu1Sm 0.4 Ti 0.1 .

[0071] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip is similar to that in Example 1, except that the vanadium rod is replaced by a titanium plate in the alloy raw material. The other conditions are the same as those in Example 1 and will not be described in detail.

[0072] Comparative Example 6 This comparative example provides an iron-based amorphous soft magnetic alloy casting strip Fe 70 Ni 13 B7 6.58 C 0.42 Nb 1.5 Cu1Sm 0.4 V 0.1 .

[0073] The method for preparing the above-mentioned iron-based amorphous soft magnetic alloy casting strip is similar to that in Example 1, except that the industrial cobalt in the alloy raw material is replaced by nickel plate. The other conditions are the same as those in Example 1 and will not be described in detail.

[0074] Comparative Example 7 This comparative example provides an iron-based amorphous soft magnetic alloy casting strip Fe 70 Co 13 B7Si7Nb 1.5 Cu1Sm 0.4 V 0.1 .

[0075] The preparation method of the above-mentioned iron-based amorphous soft magnetic alloy casting strip is similar to that of Example 1, except that the atomic percentage of Si element is different and the addition of carbon powder is omitted. The remaining conditions are the same as those of Example 1 and will not be described in detail.

[0076] Comparative Example 8 This comparative example provides an iron-based amorphous soft magnetic alloy casting strip Fe 70 Co 13 B7Si7Nb2Cu1.

[0077] The preparation method of the above-mentioned iron-based amorphous soft magnetic alloy casting strip is similar to that of Example 1, except that the atomic percentages of Si and Nb elements are different, and the addition of carbon powder, samarium powder and vanadium rod is omitted. The remaining conditions are the same as those of Example 1 and will not be described in detail.

[0078] Comparative Example 9 This comparative example provides a method for preparing an iron-based amorphous soft magnetic alloy casting strip (a step-by-step heat treatment method, first annealing treatment, then longitudinal magnetic field heat treatment), comprising the following steps: S1~S3 are the same as those in Example 1 and will not be described in detail.

[0079] S4, annealing the alloy strip at 520℃ for 25min, cooling it to 320℃, and then cooling it to room temperature; then performing longitudinal magnetic field heat treatment at 340℃ and 1000Oe for 35min, and quenching it to room temperature to obtain an iron-based amorphous soft magnetic alloy casting strip Fe with a thickness of 12μm and a width of 160mm. 70 Co 13 B7 6.58 C 0.42 Nb 1.5 Cu1Sm 0.4 V 0.1 .

[0080] Comparative Example 10 This comparative example provides a method for preparing an iron-based amorphous soft magnetic alloy casting strip (only annealing treatment is performed), comprising the following steps: S1~S3 are the same as those in Example 1 and will not be described in detail.

[0081] S4, annealing the alloy strip at 520°C for 25 min, cooling it to 320°C with the furnace, and then cooling it to room temperature with air to obtain an iron-based amorphous soft magnetic alloy casting strip Fe with a thickness of 12 μm and a width of 160 mm. 70 Co 13 B7 6.58 C 0.42 Nb 1.5 Cu1Sm 0.4 V 0.1 .

[0082] Comparative Example 11 This comparative example provides a method for preparing an iron-based amorphous soft magnetic alloy casting strip (only longitudinal magnetic field heat treatment is performed), comprising the following steps: S1~S3 are the same as those in Example 1 and will not be described in detail.

[0083] S4, the alloy strip is subjected to longitudinal magnetic field heat treatment at 340°C and 1000 Oe for 35 min, and water quenched to room temperature to obtain an iron-based amorphous soft magnetic alloy casting strip Fe with a thickness of 12 μm and a width of 160 mm. 70 Co 13 B7 6.58 C 0.42 Nb 1.5 Cu1Sm 0.4 V 0.1 .

[0084] Performance Testing The magnetic properties of the iron-based amorphous soft magnetic alloy casting strips provided in Examples 1 to 5 and Comparative Examples 1 to 11 were tested using a vibration test magnetometer (VSM, Lakeshore 7410), an AC / DC magnetic BH meter (ACBH-100K / EXPH-100, Hitachi, Japan) and an impedance analyzer (Agilent 4294A), respectively. The test results are shown in Table 1. The meanings of the symbols in Table 1 are as follows: H c is the coercive force, μ e is the effective magnetic permeability, B s is the saturation magnetization.

[0085] Table 1 Performance test results of alloy casting strips of embodiments and comparative examples

[0086] It can be seen from the table that the iron-based amorphous soft magnetic alloy casting strip with specific chemical composition and atomic ratio provided by the present invention has excellent soft magnetic properties such as high saturation magnetic induction intensity, high magnetic permeability and low coercive force; the step-by-step heat treatment method is adopted, first longitudinal magnetic field heat treatment and then annealing treatment, which can optimize the grains and make the amorphous structure more uniform, thereby ensuring the soft magnetic properties of the alloy casting strip.

[0087] It can be seen from the test results of Example 1 and Comparative Examples 1~3 and Comparative Example 6 that the Co element and the Fe element in a specific ratio have a large ferromagnetic interaction strength, which can synergistically improve the saturation magnetic induction intensity of the iron-based amorphous alloy. If the ratio of the Co element to the Fe element is broken, its soft magnetic properties will be greatly reduced. Compared with Example 1, the content of metalloid elements in the alloy casting strip of Comparative Example 3 is 22at%. It can be seen that the soft magnetic properties of the iron-based amorphous alloy casting strip will be deteriorated after the content of metalloid elements increases. It can be seen from the test results of Example 1 and Comparative Examples 7~8 that adding a trace amount of C element on the basis of Fe, Co, B and Si elements will not only not increase the difficulty of production and processing, but also effectively improve the magnetic permeability and reduce the coercive force of nanocrystals. It can be seen from the test results of Example 1 and Comparative Examples 4~5 that although they are both rare earth elements, compared with Nd elements, Sm elements have a better effect on improving the soft magnetic properties of alloy casting strips; although they are both transition metal elements, compared with Ti elements, V elements have a better effect on improving the soft magnetic properties of alloy casting strips. Furthermore, it can be seen from the test results of Comparative Examples 7 and 8 that after replacing the Sm element and the V element with the Nb element, the synergistic effect between the transition metal elements cannot be achieved, and the soft magnetic properties of the alloy casting strip are further reduced.

[0088] It can be seen from the test results of Example 1 and Comparative Examples 9 to 11 that changing the step-by-step heat treatment method of first longitudinal magnetic field heat treatment and then annealing treatment will cause the soft magnetic properties of the obtained alloy strip to decrease to varying degrees.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An iron-based amorphous soft magnetic alloy casting strip, characterized in that: Its chemical formula is Fe a Co b B c Si d C e Nb f Cu g Sm h V i , a, b, c, d, e, f, g, h and i represent the atomic percentages of the corresponding chemical components; Among them, a=68~72, b=11~15, c=6~7.5, d=5.5~7.1, e=0.3~0.5, f=1.2~2, g=0.4~1.5, h=0.3~1, i=0.1~0.5, and a+b+c+d+e+f+g+h+i=100.

2. The iron-based amorphous soft magnetic alloy casting strip according to claim 1, characterized in that: a+b=83.

3. The iron-based amorphous soft magnetic alloy casting strip according to claim 1, characterized in that: c+d+e=12~15.

4. The iron-based amorphous soft magnetic alloy casting strip according to claim 1 or 3, characterized in that: c:d:e=(48~52):(45~50):

3.

5. The iron-based amorphous soft magnetic alloy casting strip according to claim 1, characterized in that: The iron-based amorphous soft magnetic alloy casting strip has a thickness of 5 μm to 16 μm and a width of 120 mm to 220 mm.

6. The method for preparing the iron-based amorphous soft magnetic alloy casting strip according to claims 1 to 5, characterized in that: The following steps are involved: S1, weighing alloy raw materials according to the atomic percentage of chemical components, and performing vacuum induction melting and casting on the alloy raw materials under a protective atmosphere to obtain a master alloy ingot; S2, in a protective atmosphere, subjecting the master alloy ingot to vacuum induction remelting to obtain a remelted metal liquid; S3, using a twin-roll casting method to spray the remelted metal liquid onto the surface of a copper roll to obtain an alloy strip; S4, subjecting the alloy strip to a longitudinal magnetic field heat treatment at 320° C. to 350° C., and then to a first cooling; After annealing at 480°C-550°C, a second cooling is performed to obtain an iron-based amorphous soft magnetic alloy casting strip.

7. The method for preparing the iron-based amorphous soft magnetic alloy casting strip according to claim 6, characterized in that: In S1, during the vacuum induction melting, the vacuum is first evacuated to a pressure of (6~9.5)×10 -3 Pa, then introduce protective gas until the pressure is 60Pa~100Pa; In S1, the temperature of the vacuum induction melting is 1600° C. to 1800° C. After the alloy raw material is melted, it is kept warm and stirred for 10 min to 20 min.

8. The method for preparing the iron-based amorphous soft magnetic alloy casting strip according to claim 6, characterized in that: In S2, during the vacuum induction remelting, the vacuum is first evacuated to a pressure of (6~9.5)×10 -3 Pa, then introduce protective gas until the pressure is 60Pa~100Pa; In S2, the temperature of the vacuum induction remelting is 1400° C. to 1500° C. After the master alloy ingot is melted, it is kept warm and stirred for 5 min to 8 min.

9. The method for preparing the iron-based amorphous soft magnetic alloy casting strip according to claim 6, characterized in that: In S3, the rolling force of the twin-roll casting method is 20 kN to 40 kN; In S3, the linear speed of the copper roller surface is 1 m / s to 2 m / s.

10. The method for preparing the iron-based amorphous soft magnetic alloy casting strip according to claim 6, characterized in that: In S4, the magnetic field intensity of the longitudinal magnetic field heat treatment is 800Oe~1200Oe, and the time of the longitudinal magnetic field heat treatment is 30min~40min; In S4, the annealing time is 20min to 30min; In S4, the first cooling method is water quenching; In S4, the second cooling method is to cool the steel sheet to 300° C.-350° C. in the furnace and then air cool the steel sheet out of the furnace.

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