CN108461246B - A kind of iron-based amorphous soft magnetic alloy and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of novel iron base amorphous magnetically-soft alloy and preparation method thereof, the expression formula of the alloy is Fe_aSi_bB_cP_dCu_eNb_fA, b, c, d, e and f respectively indicate the atom percentage content of each corresponding component in expression formula, and meet the following conditions: a is 75~85, it be 7.5~14, d is 0.2~1.5 that b, which is 0.02~4, c, e is 0.1~1.0, f is 0~1.50, a+b+c+d+e+f=100, with high saturation induction density B_s, high Effective permeability μ_e, low coercivity H_c, excellent high frequency stability, and its good moldability, preparation process condition are simple, low production cost.

Description

A kind of iron-based amorphous soft magnetic alloy and preparation method thereof

technical field

The invention belongs to the technical field of amorphous alloys, and specifically relates to an iron-based amorphous soft magnetic alloy, which is a soft magnetic amorphous alloy with high μ _e , low H _c and high B _s developed by adding trace elements .

Background technique

Amorphous materials have the remarkable characteristics of green energy saving. Especially iron-based amorphous alloys have high resistivity, high magnetic permeability, and very low loss. Its loss is only equivalent to 1/3 to 1/5 of oriented silicon steel. In addition, compared with silicon steel, the process is simple. No special processing is required, so it is considered to be an ideal core material for power transformers. However, compared with silicon steel, iron-based amorphous alloy still has its disadvantages, that is, the filling factor and saturation magnetic induction are relatively low. For example, the B _s value of crystalline grain-oriented silicon steel is about 2T, while the B _s value of a typical iron-based amorphous alloy Fe ₇₈ Si ₉ B _l3 is 1.56T. In addition, when preparing magnetic components, such as transformer cores, motor rotors and magnetic switches, etc., it is often desired that the saturation magnetic induction of these devices is high, because this means that the size of the device is reduced or the excitation power is reduced. For fill factor, a common approach is to improve strip surface quality, such as surface finish and uniformity of strip thickness. However, since the amorphous ribbon itself is only a few tens of microns, the potential for increasing the fill factor is limited. People are doing more research and development of amorphous soft magnetic alloys with high magnetic saturation.

Tohoku University in Japan announced a FeSiBPCu-based nanocrystalline alloy in patent CN102741437A. This alloy has the advantage of high saturation magnetic induction. The saturation magnetic induction of its typical active ingredient Fe _83.3-84.3 Si ₄ B ₈ P _3-4 Cu _0.7 reaches 1.8T or more. The introduction of P in this alloy can play a role in inhibiting the precipitation of large-sized primary crystal phases and refine the grains during the nanocrystallization process. However, there are still three key problems in the large-scale production of this alloy: 1) In order to take advantage of the effect of P on grain refinement, a high P content is used in the design, making the alloy extremely sensitive to impurities, which cannot be obtained under the existing smelting process. Prepared from industrial raw materials. 2) The addition of a large amount of P significantly reduces the oxidation resistance and corrosion resistance of the alloy. 3) The alloy has strict heat treatment conditions, and also fails to overcome the requirement of high heating rate in the heat treatment process.

In the patent CN101834046A of Ningbo Institute of Materials Science, Chinese Academy of Sciences, a FeSiBPCu nanocrystalline alloy with a similar composition is announced. The typical composition of this alloy is Fe _82.7 Si _3.95 B _8.4 P _4.3 Cu _0.6 . The thermal stability is poor, and the heat treatment time is extremely short, which obviously does not meet the requirements of industrialization. , while the alloy also failed to overcome the problem of industrial raw materials.

Wangwei New Materials (Pizhou) Co., Ltd. disclosed a Fe _a Si _b B _c P _d Cu _e Me _f iron-based amorphous nanocrystalline soft magnetic alloy in patent CN105261435A.

CN102741437A discloses that the BCC iron phase with an average size of 10-25nm will be precipitated after heat treatment of the FeSiBCuP-based amorphous alloy, so that the saturation magnetic induction can reach 1.8-1.9T. However, the heat treatment in the preparation process will inevitably increase the processing process and increase the production cost.

Nanjing University of Aeronautics and Astronautics announced a FeSiBPCu nanocrystalline alloy with high Si content in patent CN200910184483.4. The content of metalloid elements in this alloy is unreasonably designed, and the ability to form amorphous is low. It is difficult to prepare completely amorphous by conventional strip making process. alloy strip.

To sum up, the current market lacks iron-based amorphous nanocrystals and their products with stable performance and good production technology. It is necessary to develop amorphous soft magnetic alloys with high magnetic induction intensity and high amorphous forming ability based on industrial raw materials, and Its supporting preparation method.

Contents of the invention

Aiming at the above problems, the present invention develops a new type of iron-based amorphous soft magnetic alloy with high μ _e , low H _c , high B _s , good formability, simple preparation process conditions and low production cost.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

The invention provides an iron-based amorphous soft magnetic alloy, the expression of the alloy is Fe _a Si _b B _c P _d Cu _e Nb _f , in the expression a, b, c, d, e and f Respectively represent the atomic percentage content of each corresponding component, and meet the following conditions: a is 75-85, b is 0.02-4, c is 7.5-14, d is 0.2-1.5, e is 0.1-1.0, f is 0～1.50, a+b+c+d+e+f=100.

According to the above iron-based amorphous soft magnetic alloy, a is 80-84, b is 2-3, c is 9.5-12.50, d is 1.0-1.30, e is 0.2-0.7, and f is 0-1.0.

According to the aforementioned iron-based amorphous soft magnetic alloy, a is 83.33, b is 2.35, c is 12.17, d is 1.25, e is 0.70, and f is 0.20.

According to the aforementioned iron-based amorphous soft magnetic alloy, a is 83.08, b is 2.34, c is 12.14, d is 1.24, e is 0.70, and f is 0.50.

According to the aforementioned iron-based amorphous soft magnetic alloy, a is 82.66, b is 2.33, c is 12.08, d is 1.24, e is 0.69, and f is 1.00.

According to the preparation method of above-mentioned iron-based amorphous soft magnetic alloy, it comprises the following steps:

(1) batching: select the Fe that purity is 99.99wt%, purity is the Si of 99.99wt%, B content is the FeB of 17.40wt%, P content is the FeP of 24.98wt%, purity is the Cu of 99.99wt% and purity is 99.99wt% Nb is used as a raw material, and the ingredients are prepared according to the atomic percentage content in the above alloy expression;

(2) Melting master alloy: Put the above-mentioned prepared raw materials into a vacuum high-frequency induction melting furnace, vacuumize to 2~3×10 ^-3 Pa, and fill in argon protective gas with a pressure of 0.04~0.05MPa; adjust The current is 15-25A, the melting temperature is 1000-1600°C, and the master alloy ingot is obtained by cooling with the furnace after melting for 5-10 minutes;

(3) Strip preparation: under discontinuous production conditions, the master alloy ingot prepared above was re-melted and sprayed on a high-speed rotating copper wheel to prepare an iron-based amorphous thin strip. The surface speed of the copper wheel was 20 ~30m/s.

In the above-mentioned step (2), the ingredients are carried out according to the above-mentioned atomic percentage content. The order of placing the raw materials is set according to the melting point of the raw material components. The alloy steel or alloy elements with a low melting point in the raw material components are placed on the upper layer, and the alloy steel with a high melting point Or alloying elements are placed in the lower layer.

When using high-purity raw materials to prepare the master alloy, use a mechanical pump and a diffusion pump to evacuate in turn. When the vacuum reaches 2.0-3.0×10 ^-3 Pa, fill it with argon gas with a purity of 0.04-0.05 MPa and a purity of 99.999% as a protective gas. Then start to smelt the master alloy; when using industrially pure raw materials to prepare the master alloy, after batching in step (2), add 1 to 2% of the total mass of the raw material as an impurity adsorbent, the impurity adsorbent is dried _{B2O 3.} Then put it into the induction coil in the vacuum induction melting cavity, and then use the mechanical pump and the diffusion pump to evacuate the vacuum successively. When the vacuum degree reaches 2.0～3.0×10 ^-3 Pa, fill it with 0.04～0.05MPa and the purity is 99.999%. The argon gas is used as the protective gas, and then the master alloy is melted, and the impurity adsorbent is used for coating. After the melting is completed, the alloy liquid is coated for 20 minutes, and the power is turned off.

In the above step (3), put the smelted master alloy into a quartz tube with a round hole at the bottom and a diameter of 0.6 mm to 0.7 mm, then place it in the induction coil in the vacuum chamber and fix it on the copper wheel At a height of 0.5-1.2mm, vacuumize to 5.0-6.0× ^10-3 Pa with a mechanical pump and a diffusion pump in turn, then fill in 0.04-0.05MPa of argon with a purity of 99.999% as a protective gas, and then turn on the cooling water Copper wheel and induction heating power supply, adjust current 2-10A, induction temperature 900-1100°C, melting time 2-5min, and then use high-frequency induction heating under the protection of argon to melt the master alloy in the quartz tube evenly , and then the uniformly molten master alloy is sprayed onto a high-speed rotating copper wheel under the pressure difference between the inside and outside of the quartz tube of 0.05 MPa to prepare strips.

The atomic percent content of Fe in the alloy of the invention is in the range of 75-85 (at%), which ensures the amorphous forming ability and high B _s .

Cu element can promote nucleation, but its effect is significantly different with the microstructure in the as-quenched strip. In the present invention, the low Cu content is designed so as not to greatly reduce the amorphous forming ability of the alloy. For the promotion of nucleation of Cu element with low addition amount, the present invention mainly realizes by increasing Fe content and introducing P and C elements, so that there are a large number of high-density clusters as nucleation points in Quenjie strip without causing Formation of coarse primary crystal phase.

Nb can effectively improve the crystallization activation energy. In addition, Nb interacts with B atoms at the phase boundary to form atomic groups, which hinders the growth of α-Fe solid solution and is conducive to the formation of nanocrystals.

The appropriate content of P element in the alloy is beneficial to improve the amorphous formation ability of the alloy, and the effect of P on the formation of the amorphous phase of FeSiBP alloy is greater than that of Si and B.

The main function of the Si element is to increase the amorphous formation energy, and appropriately increase the thermal stability and Curie temperature of the alloy. If the Si element is too low, it is difficult to play its role in improving the amorphous formation energy, and if the content is too high, it may reduce the ferromagnetic element. content, thereby reducing the saturation magnetic induction of the alloy. Therefore, the preferred range of Si in the present invention is 2 to 3 (at%).

B and Fe elements have a large difference in atomic radius, which meets the requirement of having a large difference in atomic radius in Inoue's three principles, and is conducive to the amorphization of Fe-based alloys. B content is above 9 (at%), can significantly improve the amorphous forming ability and stability of alloy, and when its content is lower than 5 (at%), the thermal stability of amorphous soft magnetic material becomes poor, but when B content When the content is higher than 18 (at%), the increase of its content basically does not contribute much to the amorphization of the alloy, so the preferred range of B content in the present invention is 9.5-12.5 (at%).

Compared with prior art, the beneficial effect that the present invention obtains:

1. The alloy composition designed in the present invention has strong compatibility with impurities and can be produced by utilizing industrial raw materials.

2. The alloy system of the present invention does not require nanocrystallization annealing to obtain nanocrystals, and obtains excellent soft magnetic properties in an amorphous state.

3. The alloy strip of the present invention contains a small amount or no precious metal elements, which reduces costs while obtaining high performance, and is beneficial to industrial applications.

In summary, the iron-based amorphous soft magnetic alloy of the present invention has excellent comprehensive properties, and it has a high saturation magnetic induction B _s (up to 1.58T), high effective permeability μ _e (up to 12717 at 1kHz) And high frequency stability, low coercive force H _c (minimum 3.432A/m) and good amorphous forming ability.

Description of drawings

Fig. 1 is the XRD figure of embodiment 1～3 iron-based amorphous soft magnetic alloy; Among the figure, abscissa is scanning angle, and ordinate is intensity;

Fig. 2 is the DSC figure of embodiment 1～3 iron-based amorphous soft magnetic alloy; Among the figure, abscissa is temperature, and ordinate is heat release;

Fig. 3 is the VSM figure under the different applied magnetic fields of embodiment 1～3 iron-based amorphous soft magnetic alloy; Among the figure, abscissa is magnetic field intensity, and ordinate is magnetization intensity;

Fig. 4 is the magnetic permeability figure of embodiment 1～3 iron-based amorphous soft magnetic alloy under different applied frequencies; Among the figure, abscissa is frequency, and ordinate is effective magnetic permeability;

Fig. 5 is the coercive force figure under the different applied magnetic fields of embodiment 1～3 iron-based amorphous soft magnetic alloy; Among the figure, abscissa is magnetic field intensity, and ordinate is magnetization intensity;

Among the figure, X1 is embodiment 1, X2 is embodiment 2, and X3 is embodiment 3.

Detailed ways

The present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited thereto.

Example 1

The present invention provides an iron-based amorphous soft magnetic alloy Fe _83.33 Si _2.35 B _12.17 P _1.25 Cu _0.70 Nb _0.20 (at%), denoted as X1, and its preparation method comprises the following steps:

1) Ingredients: Fe with a purity of 99.99wt%, Si with a purity of 99.99wt%, FeB with a B content of 17.40wt%, FeP with a P content of 24.98wt%, Cu with a purity of 99.99wt%, and Cu with a purity of 99.99wt% Wt% Nb is used as a raw material, and the ingredients are prepared according to the atomic percentage content in the above alloy expression. The placement order of the raw materials is set according to the melting point of the raw material components. Alloy steel or alloy elements with high melting point are placed in the lower layer;

2) Melting the master alloy: first put the master alloy components prepared above into a quartz crucible, then add dried B ₂ O ₃ of 1% of the total mass of raw materials into the ingredients, and then put the B 2 O 3 in the vacuum induction melting cavity In the induction coil, use a mechanical pump and a diffusion pump to evacuate in turn. When the vacuum reaches 3.0×10 ^-3 Pa, fill it with argon gas with a purity of 0.04 to 0.05 MPa and a purity of 99.999% as a protective gas; adjust the current to 15A and the melting temperature to 1600 ℃ to start melting the master alloy, and use B ₂ O ₃ to coat it. After the melting is completed, coat the alloy solution for 20 minutes, turn off the power, and finally prepare a master alloy ingot with a uniform composition;

3) Strip preparation: After cutting the smelted master alloy, take 7g and put it into a quartz tube with a round hole at the bottom and a diameter of 0.6mm, then place it in the induction coil in the vacuum chamber and fix it At a height of 0.8mm above the copper wheel, vacuumize to 5.0×10 ^-3 Pa with a mechanical pump and a diffusion pump in sequence, then fill in 0.04MPa of argon gas with a purity of 99.999%, and then turn on the copper wheel with cooling water and induction Heating power supply, adjusting current 5A, induction temperature 950°C, smelting time 3min, then using high-frequency induction heating under the protection of high-purity argon to melt the master alloy in the quartz tube evenly, and then the pressure difference inside and outside the quartz tube is Spray the uniformly molten master alloy onto a high-speed rotating copper wheel under 0.05MPa, and the surface speed of the copper wheel is 25m/s to prepare a thin strip X1.

Example 2

The invention provides a novel iron-based soft magnetic amorphous steel Fe _83.08 Si _2.34 B _12.14 P _1.24 Cu _0.70 Nb _0.50

(at%), denoted as X2. Its preparation method comprises the following steps:

1) Ingredients: Fe with a purity of 99.99wt%, Si with a purity of 99.99wt%, FeB with a B content of 17.40wt%, FeP with a P content of 24.98wt%, Cu with a purity of 99.99wt%, and Cu with a purity of 99.99wt% Wt% Nb is used as a raw material, and the ingredients are prepared according to the atomic percentage content in the above alloy expression. The placement order of the raw materials is set according to the melting point of the raw material components. Alloy steel or alloy elements with high melting point are placed in the lower layer;

2) Melting the master alloy: first put the master alloy components prepared above into a quartz crucible, then add 2% of the total mass of raw materials into the batch of dried B ₂ O ₃ , and then put the B 2 O 3 in the vacuum induction melting cavity In the induction coil, use a mechanical pump and a diffusion pump to evacuate in turn. When the vacuum reaches 2.0×10 ^-3 Pa, fill it with 0.05MPa argon with a purity of 99.999% as a protective gas; adjust the current to 25A, and start the melting temperature at 1500°C Melt the master alloy and coat it with B ₂ O ₃ . After the smelting is completed, coat the alloy solution for 20 minutes, turn off the power, and finally prepare a master alloy ingot with a uniform composition;

2) 3) Strip preparation: After cutting the smelted master alloy, take 8g and put it into a quartz tube with a round hole at the bottom and a diameter of 0.6mm, and then place it in the induction coil in the vacuum chamber And fix it at a height of 1.2mm above the copper wheel, use a mechanical pump and a diffusion pump to evacuate to 5.5×10 ^-3 Pa in turn, fill it with 0.05MPa argon gas with a purity of 99.999%, and then turn on the copper wheel with cooling water And induction heating power supply, adjust current 6A, induction temperature 1100 ℃, melting time 2min, then use high-frequency induction heating under the protection of high-purity argon to melt the master alloy in the quartz tube evenly, and then press the inside and outside of the quartz tube Spray the uniformly melted master alloy onto a high-speed rotating copper wheel with a difference of 0.05 MPa, and the surface line speed of the copper wheel is 30m/s to prepare a thin strip X2.

Example 3

The invention provides a novel iron-based soft magnetic amorphous steel Fe _82.66 Si _2.33 B _12.08 P _1.24 Cu _0.69 Nb _1.0

(at%), denoted as X3. Its preparation method comprises the following steps:

1) Ingredients: Fe with a purity of 99.99wt%, Si with a purity of 99.99wt%, FeB with a B content of 17.40wt%, FeP with a P content of 24.98wt%, Cu with a purity of 99.99wt%, and Cu with a purity of 99.99wt% Wt% Nb is used as a raw material, and the ingredients are prepared according to the atomic percentage content in the above alloy expression. The placement order of the raw materials is set according to the melting point of the raw material components. Alloy steel or alloy elements with high melting point are placed in the lower layer;

2) Melting the master alloy: first put the master alloy components prepared above into a quartz crucible, then add 2% of the total mass of raw materials into the batch of dried B ₂ O ₃ , and then put the B 2 O 3 in the vacuum induction melting cavity In the induction coil, use a mechanical pump and a diffusion pump to evacuate in turn. When the vacuum reaches 2.0×10 ^-3 Pa, fill it with 0.05MPa argon with a purity of 99.999% as a protective gas; adjust the current to 20A, and start the melting temperature at 1000°C Melt the master alloy and coat it with B ₂ O ₃ . After the smelting is completed, coat the alloy solution for 20 minutes, turn off the power, and finally prepare a master alloy ingot with a uniform composition;

3) Strip preparation: After cutting the smelted master alloy, take 8g and put it into a quartz tube with a round hole at the bottom and a diameter of 0.6mm, then place it in the induction coil in the vacuum chamber and fix it At a height of 0.8mm above the copper wheel, vacuumize to 6.0×10 ^-3 Pa with a mechanical pump and a diffusion pump in sequence, then fill in 0.05MPa of argon gas with a purity of 99.999%, and then turn on the copper wheel with cooling water and induction Heating power supply, adjusting current 8A, induction temperature 1000°C, smelting time 3min, then using high-frequency induction heating under the protection of high-purity argon to melt the master alloy in the quartz tube evenly, and then the pressure difference inside and outside the quartz tube is Spray the uniformly melted master alloy onto a high-speed rotating copper wheel under 0.05MPa, and the surface speed of the copper wheel is 20-30m/s to prepare thin strip X3.

The obtained X1, X2, X3 iron-based amorphous soft magnetic alloys were detected by X-ray diffractometer (X-raydiffraction, XRD; UItima IV diffractometer, Japan; Cu-Kα) to detect the structure of the sample; using differential scanning calorimetry Method (NETZSCH STA type Differential scanning calorimetry, DSC) with a heating rate of 20 ℃ / min to measure the initial crystallization temperature T _x of the sample, the XRD and DSC curves of the iron-based amorphous alloy can be obtained, as shown in Figure 1 and Figure 2 , see Table 1 for specific T _x values.

Put the obtained iron-based amorphous soft magnetic alloy into a quartz tube, vacuumize it, and seal the tube when the vacuum degree is 2.0×10 ^-3 Pa, and then perform stress relief annealing in a box furnace at an annealing temperature of T _x -100°C, hold for about 10 minutes, then use a vibrating sample magnetometer (VSM; 7410, Lake Shore, USA) to measure the B _s of the annealed sample, and use a DC hysteresis loop measuring instrument (BHS -40, Riken, Japan) to measure the H _c of the annealed sample, and use an impedance analyzer (4294A, Agilent, the United States) to measure the μ _e of the stress-relieved annealed sample under the external excitation magnetic field of different frequencies. The results are shown in Table 1, Fig. 3, Figure 4, Figure 5

Table 1 Comprehensive performance table of iron-based amorphous soft magnetic alloy X1～X3

Claims (1)

1. An iron-based amorphous soft magnetic alloy, characterized in that the expression of the alloy is Fe _83.08 Si _2.34 B _12.14 P _1.24 Cu _0.70 Nb _0.50 , and the preparation method of the iron-based amorphous soft magnetic alloy comprises The following steps: (1) Ingredients: Fe with a purity of 99.99wt%, Si with a purity of 99.99wt%, FeB with a B content of 17.40wt%, FeP with a P content of 24.98wt%, Cu with a purity of 99.99wt%, and a purity of The Nb of 99.99wt% is used as a raw material, and the ingredients are carried out according to the atomic percentage content in the above-mentioned alloy expression; (2) Melting master alloy: Put the above-mentioned prepared raw materials into a vacuum high-frequency induction melting furnace, vacuumize to 2~3×10-3Pa, fill in argon protective gas with a pressure of 0.04~0.05MPa; adjust the current 15-25A, melting temperature 1000-1600°C, smelting for 5-10 minutes and then cooling with the furnace to obtain master alloy ingots; (3) Strip preparation: Under discontinuous production conditions, the master alloy ingot prepared above is remelted, and after melting, it is sprayed on a high-speed rotating copper wheel to prepare an iron-based amorphous thin strip. The surface speed of the copper wheel is 20~30m/s; In step (1), the ingredients are prepared according to the above atomic percentage content. The order of placing the raw materials is set according to the melting point of the raw material components. The alloy steel or alloy elements with low melting point in the raw material components are placed on the upper layer, and the alloy steel or Alloying elements are placed in the lower layer; After batching in step (2), add 1-2% impurity adsorbent of the total mass of raw materials into the batching, then put it into the induction coil in the vacuum induction melting cavity, and use the mechanical pump and the diffusion pump to evacuate in turn, when the vacuum After the temperature reaches 2.0～3.0×10-3 Pa, it is filled with argon gas with a purity of 0.04～0.05 MPa and a purity of 99.999% as a protective gas, and then the master alloy is smelted, and the impurity adsorbent is used for coating. After the smelting is completed, the alloy liquid is Carry out 20min coating, turn off the power supply; In step (3), put the smelted master alloy into a quartz tube with a round hole at the bottom and a diameter of 0.6 mm to 0.7 mm, then place it in the induction coil in the vacuum chamber and fix it 0.5 mm above the copper wheel. At a height of ~1.2 mm, the mechanical pump and the diffusion pump are used to evacuate to 5.0 ~ 6.0×10-3Pa, and then filled with 0.04 ~ 0.05MPa argon gas with a purity of 99.999% as a protective gas, and then open the copper tube with cooling water. Wheel and induction heating power supply, adjust the current 2~10A, induction temperature 900~1100℃, melting time 2~5min, under the protection of argon, adopt high-frequency induction heating to melt the master alloy in the quartz tube evenly, and then Under the condition that the pressure difference between the inside and outside of the quartz tube is 0.04-0.05MPa, the uniformly melted master alloy is sprayed onto the high-speed rotating copper wheel to prepare the strip; The impurity adsorbent in step (2) is dried B ₂ O ₃ .