Preparation method of high-resistivity amorphous nanocrystalline composite soft magnetic material

Abstract

The invention discloses a preparation method of a high-resistivity amorphous nanocrystalline composite soft magnetic material, and relates to the field of amorphous nanocrystalline preparation, the preparation method comprises the following steps: 1, preparing an amorphous ribbon: smelting an alloy raw material in a vacuum induction smelting furnace, 2, preparing the amorphous ribbon from the smelted raw material at a roller speed of 15-40m / s through a single-roller rapid quenching method, and 3, preparing the amorphous ribbon into a high-resistivity amorphous nanocrystalline composite soft magnetic material. Thirdly, nanocrystalline annealing is conducted, specifically, the amorphous thin strip is placed in an inert gas shielding annealing furnace to be annealed; the surface of the annealed amorphous ribbon is insulated through the atomic layer deposition technology, the composite structure is assembled, the amorphous ribbon can be effectively prevented from being oxidized in the high-temperature treatment process through precise temperature control of an inert gas protection annealing furnace and a hot-pressing device, and the high-resistance layer is formed. The surface quality of the material and the stability of the internal structure are ensured. The precise control can significantly improve the performance consistency of the material.

Description

Technical Field

[0001] This invention relates to the field of amorphous nanocrystal preparation, and particularly to a method for preparing a high resistivity amorphous nanocrystal composite soft magnetic material. Background Technology

[0002] With the rapid development of modern electronic technology and power engineering, the demand for high-performance soft magnetic materials is increasing. Amorphous and nanocrystalline composite soft magnetic materials, due to their excellent soft magnetic properties, high resistivity, low coercivity, and high saturation magnetic induction, have broad application prospects in high-frequency transformers, inductors, motors, and other equipment. These materials can maintain high permeability and low loss under high-frequency conditions, significantly improving the efficiency and power density of electronic devices.

[0003] In existing hot pressing devices, oxygen in the air easily reacts with the hot-pressed amorphous ribbon during the hot pressing process, which affects the quality of the amorphous ribbon.

[0004] Therefore, it is necessary to propose a method for preparing high resistivity amorphous nanocrystalline composite soft magnetic materials to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing high resistivity amorphous nanocrystalline composite soft magnetic materials, in order to solve the problem that when existing hot pressing devices are used to hot press amorphous strips, oxygen in the air easily reacts with the hot-pressed amorphous strips, affecting the quality of the amorphous strips.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material, comprising the following steps:

[0007] Step 1, Amorphous ribbon preparation: The alloy raw materials are melted in a vacuum induction melting furnace, and the melt temperature is controlled at 1450-1600℃;

[0008] The second step is to prepare amorphous ribbons by using a single-roller rapid quenching method at a roller speed of 15-40 m / s on the smelted raw materials.

[0009] Step 3, Nanocrystallization Annealing: The amorphous ribbon is placed in an inert gas protected annealing furnace for annealing;

[0010] Step 4: High-resistivity layer deposition: An insulating layer is deposited on the surface of the annealed amorphous ribbon using atomic layer deposition technology.

[0011] Step 5: Composite structure assembly: Using a hot pressing device, the multi-layer amorphous thin strips are hot pressed together;

[0012] The hot pressing device includes two lower fixed blocks, with a central tube at the top of each lower fixed block. Both ends of the central tube are connected to hot pressing cylinders. A heating base is provided at the bottom of each hot pressing cylinder. A lower pressure plate is raised and lowered inside each hot pressing cylinder.

[0013] Multiple layers of amorphous thin strips are stacked inside the hot press cylinder;

[0014] Two air holes are opened in the middle of the central tube, which are used to connect the gas supply pipeline and the vacuum pumping device, respectively.

[0015] Preferably, corresponding lower fixing blocks extend from both ends of the central tube, and a base plate is fixed to the bottom of the two lower fixing blocks. At least two hydraulic cylinders are fixed to one side of the top of the base plate.

[0016] The top of the two hydraulic cylinders is connected to a top plate, and an upper fixing block is fixed at the bottom of the top plate. The upper fixing block and the lower fixing block are positioned correspondingly, and a groove corresponding to the outer side of the central tube is opened on the opposite side of the upper fixing block and the lower fixing block.

[0017] Preferably, a fixing column is connected to the top of the lower pressure plate, and the fixing column is fixed to the top of the top plate;

[0018] The heating base has a protruding end fixed at the top, and the bottom of the hot press cylinder has a port for the protruding end to be inserted. The port is connected to the inside of the hot press cylinder, and an electric heating wire is fixed inside the heating base.

[0019] Preferably, a sealing gasket is fixed to the outside of the lower pressure plate, and the outside of the sealing gasket is in contact with the inside of the corresponding hot press cylinder.

[0020] Preferably, each of the two lower fixing blocks is fixed with an electric push rod on one side of the opposite side, and each of the two electric push rods is fixed with a push plate at the top. The top of the two push plates is provided with a groove corresponding to the outer arc of the central tube.

[0021] Preferably, a connecting block is fixed on one side of each of the two hot press cylinders, and the central tube passes through the one side of the two connecting blocks opposite to each other;

[0022] Two connecting blocks are fixed with a conveying trough at the end away from the central tube, and the conveying trough is inclined.

[0023] The end of the conveying trough away from the central tube is inclined upward, and the end of the conveying trough near the hot press cylinder is flush with the top surface of the hot press cylinder. The end of the conveying trough near the hot press cylinder corresponds to the outer arc surface of the hot press cylinder.

[0024] Preferably, the top two sides of the hot press cylinder are elastically telescopically connected with intercepting plates, and the two sides of the conveying trough are provided with baffles, with the positions of the two intercepting plates corresponding to the positions of the two baffles.

[0025] Preferably, the bottom end of the lower pressure plate is provided with a nozzle, and the top end of the top plate is fixed with a spraying mechanism. The spraying mechanism is connected to the nozzle through a pipe and is used to spray Y2O3 anti-stick coating into the hot press cylinder.

[0026] Preferably, the gas pipeline is used for argon gas.

[0027] Preferably, in the nanocrystallization annealing, the amorphous ribbon is placed in an inert gas protected annealing furnace, and first heated to a first annealing temperature of 250-320℃ at a rate of 10-30℃ / min, held for 10-30 minutes, and then heated to a second annealing temperature of 380-450℃ at a rate of 5-15℃ / min, held for 5-60 minutes, while a 1-5T transverse static magnetic field is applied simultaneously.

[0028] The technical effects and advantages of this invention are as follows:

[0029] 1. Precise temperature control through an inert gas-protected annealing furnace and hot pressing device effectively prevents the oxidation of amorphous ribbons during high-temperature processing, ensuring the surface quality and internal structural stability of the material. This precise control significantly improves the consistency of material performance.

[0030] 2. The user can place the amorphous strip on the conveying trough. The amorphous strip will automatically slide into the hot press cylinder through the inclined angle of the conveying trough. With each input, the amorphous strip will automatically fall and be stacked. By restarting the hydraulic cylinder, the lower pressure plate will be driven to descend, and the stacked amorphous strip will be hot-pressed.

[0031] 3. As the pressure plate descends, the inside of the hot press cylinder is sealed again. The vacuum pump can extract the air from the sealed environment, while another pore introduces argon gas. Under the protection of argon gas, the material is prevented from being oxidized during the hot pressing process.

[0032] 4. After hot pressing is completed, the lower pressure plate rises with the help of the hydraulic cylinder. After the lower pressure plate rises, the electric push rod extends upward, thereby driving the central tube and the hot pressing cylinder to rise. The hot-pressed material will remain at the top of the protruding end. After the hot pressing cylinder and the protruding end are completely separated, it is easy for personnel to take out the hot-pressed material. The overall hot pressing process is simple, convenient and efficient, and can complete the hot pressing of two materials at one time. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the preparation method of the high resistivity amorphous nanocrystalline composite soft magnetic material of the present invention.

[0034] Figure 2 This is a schematic diagram of the hot pressing device of the present invention.

[0035] Figure 3 For the present invention Figure 2Enlarged diagram of point A in the middle.

[0036] Figure 4 For the present invention Figure 2 Place a diagram at point B in the middle.

[0037] Figure 5 This is a schematic diagram of the structure of the lower fixing block and the upper fixing block of the present invention.

[0038] In the diagram: 1. Base plate; 2. Hydraulic cylinder; 3. Top plate; 4. Fixed column; 5. Lower pressure plate; 6. Heating base; 7. Connecting block; 8. Hot press cylinder; 9. Conveying trough; 10. Protruding end; 11. Interceptor plate; 12. Central tube; 13. Air hole; 14. Lower fixed block; 15. Upper fixed block; 16. Electric push rod; 17. Slot; 18. Spraying mechanism. Detailed Implementation

[0039] This invention provides, for example Figures 1-5 The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material includes the following steps:

[0040] S1. Preparation of Amorphous Strips: The alloy raw materials are melted in a vacuum induction melting furnace, with the melt temperature controlled at 1450-1600℃. The vacuum induction melting furnace effectively prevents oxidation of the alloy during high-temperature melting, ensuring the purity and compositional uniformity of the alloy. Precise control of the melt temperature guarantees the melting quality of the alloy, providing a good foundation for subsequent rapid quenching processes.

[0041] S2. Amorphous ribbons are prepared by using a single-roll rapid quenching method at a roll speed of 15-40 m / s on the molten raw material. The single-roll rapid quenching method is a highly efficient technique for preparing amorphous ribbons. By rapidly cooling the melt, grain growth can be effectively suppressed, forming an amorphous structure. Precise control of the roll speed ensures the uniformity of the amorphous ribbon thickness and improves the consistency of material properties.

[0042] S3, Nanocrystallization Annealing: The amorphous ribbon is placed in an inert gas protected annealing furnace for annealing. The inert gas protection can effectively prevent the amorphous ribbon from being oxidized during the high-temperature annealing process, ensuring the surface quality and internal structure stability of the material.

[0043] In the nanocrystallization annealing, the amorphous ribbon is placed in an inert gas protected annealing furnace, and the temperature is first raised to the first annealing temperature of 250-320℃ at a rate of 10-30℃ / min, and held for 10-30 minutes to allow the atoms in the amorphous ribbon to begin to diffuse and rearrange, preparing for the subsequent nanocrystallization process.

[0044] The temperature is then increased to the second annealing temperature of 380-450℃ at a rate of 5-15℃ / min and held for 5-60 minutes, while a 1-5T transverse static magnetic field is applied simultaneously. This causes the nanocrystalline phase in the amorphous ribbon to precipitate, forming an amorphous-nanocrystalline composite structure. Simultaneously, the applied 1-5T transverse static magnetic field optimizes the magnetic domain structure, further improving the soft magnetic properties of the material.

[0045] S4. High-Resistivity Layer Deposition: Annealed amorphous ribbons are deposited using atomic layer deposition (ALD) technology to form an insulating layer on the surface. ALD technology offers high precision, uniformity, and good conformal properties, enabling the uniform deposition of thin films on complex surface structures. The deposition temperature is controlled between 80-120℃, and the layer thickness is 10-50nm. This high-resistivity layer not only improves the resistivity of the material and reduces eddy current losses but also enhances its insulation properties, improving its performance stability in high-frequency applications.

[0046] Specifically, the high-resistivity layer deposition employs plasma-enhanced ALDPE-ALD, with trimethylaluminum (TMA) and O2 plasma as the reactive gases, and a growth rate of 0.1-0.2 nm / cycle.

[0047] S5. Composite Structure Assembly: Using a hot-pressing device, multiple layers of amorphous ribbons are hot-pressed at 350-450℃ and 100-200MPa for 10-30 minutes under vacuum or Ar protection to form a bulk composite material. Precise control of temperature and pressure ensures good bonding between the multiple layers of amorphous ribbons, forming a dense and uniform composite structure. Vacuum or Ar protection prevents oxidation of the material at high temperatures, ensuring the performance stability of the composite material.

[0048] The hot pressing device includes two lower fixed blocks 14, with a central tube 12 at the top of each lower fixed block 14. Both ends of the central tube 12 are connected to hot pressing cylinders 8. A heating base 6 is provided at the bottom of each hot pressing cylinder 8. A lower pressure plate 5 is raised and lowered inside the hot pressing cylinder 8. Multiple layers of amorphous thin strips are stacked inside the hot pressing cylinder 8. A nozzle is opened at the bottom of the lower pressure plate 5. A spraying mechanism 18 is fixed at the top of the top plate 3. The spraying mechanism 18 is connected to the nozzle through a pipe. The spraying mechanism 18 is used to spray Y2O3 anti-stick coating into the hot pressing cylinder 8.

[0049] The spraying mechanism 18 includes a paint storage tank and a pump body for conveying paint. The pump body draws paint from the paint storage tank and sprays it from the nozzle. The spraying mechanism 18 can be connected to a control system for controlling the spraying time, spraying amount and spraying frequency.

[0050] The two ends of the central tube 12 extend into corresponding lower fixing blocks 14. The bottom ends of the two lower fixing blocks 14 are fixed with a base plate 1. At least two hydraulic cylinders 2 are fixed on one side of the top of the base plate 1. The hydraulic cylinders 2 are used to provide downward pressure, and the pressure is evenly transmitted to the upper fixing block 15 and the lower fixing block 14 through the top plate 3.

[0051] The top of the two hydraulic cylinders 2 is connected to the top plate 3. The bottom of the top plate 3 is fixed with an upper fixing block 15. The upper fixing block 15 and the lower fixing block 14 are in corresponding positions, and the upper fixing block 15 and the lower fixing block 14 have grooves on opposite sides that are engaged with the outer side of the central tube 12.

[0052] Before placing multiple layers of amorphous ribbon inside the hot press cylinder 8, the lower pressure plate 5 can be lowered into the hot press cylinder 8 by two hydraulic cylinders 2, so that the inside of the hot press cylinder 8 forms a closed space. At this time, by activating the spraying mechanism 18, Y2O3 anti-stick coating can be evenly sprayed onto the inner wall of the hot press cylinder 8, thereby effectively preventing the amorphous ribbon from sticking to the inner wall of the hot press cylinder 8 during the hot pressing process. Then the lower pressure plate 5 is raised to facilitate the placement of the amorphous ribbon.

[0053] Two connecting blocks 7 are fixed with a conveying groove 9 at the end away from the central tube 12. The conveying groove 9 is inclined at the end away from the central tube 12 and is inclined upward. The end of the conveying groove 9 near the hot press cylinder 8 is flush with the top surface of the hot press cylinder 8. The end of the conveying groove 9 near the hot press cylinder 8 corresponds to the outer arc surface of the hot press cylinder 8.

[0054] The user can place the amorphous strip on the conveying trough 9. The amorphous strip automatically slides into the hot press cylinder 8 through the tilt angle of the conveying trough 9. With each input, the amorphous strip automatically falls and is stacked. By restarting the hydraulic cylinder 2, the lower pressure plate 5 is driven to descend, and the stacked amorphous strip is hot-pressed.

[0055] Two air holes 13 are opened in the middle of the central tube 12. The two air holes 13 are used to connect the gas supply pipe and the vacuum device respectively. The gas supply pipe is used for argon gas. As the lower pressure plate 5 descends, the inside of the hot press cylinder 8 is sealed again. The vacuum device can extract the air in the sealed environment. At the same time, argon gas is introduced into the other air hole 13. Under the protection of argon gas, the material is prevented from being oxidized during the hot pressing process.

[0056] Furthermore, once the hot pressing is complete, the vacuum pump can be turned on again to recover the argon gas, reducing waste.

[0057] A sealing gasket is fixed on the outside of the lower pressure plate 5. The outer side of the sealing gasket is in contact with the inside of the corresponding hot pressure cylinder 8. By setting the sealing gasket, after the lower pressure plate 5 descends into the hot pressure cylinder 8, gas can be prevented from escaping from the gap between the lower pressure plate 5 and the hot pressure cylinder 8.

[0058] The top of the pressure plate 5 is connected to a fixing column 4, which is fixed to the top of the top plate 3;

[0059] Two lower fixing blocks 14 are each fixed with an electric push rod 16 on one side of each other. Each of the two electric push rods 16 has a push plate at its top. The top of each push plate has a slot 17 that corresponds to the outer arc of the central tube 12.

[0060] After the hot pressing is completed, the lower pressure plate 5 rises with the drive of the hydraulic cylinder 2. After the lower pressure plate 5 rises, the electric push rod 16 extends upward, thereby driving the central tube 12 and the hot pressing cylinder 8 to rise. The hot-pressed material will remain at the top of the protruding end 10. After the hot pressing cylinder 8 and the protruding end 10 are completely separated, it is easy for personnel to take out the hot-pressed material. The overall hot pressing process is simple and convenient, with high efficiency, and can complete the hot pressing of two materials at one time.

[0061] The heating base 6 has a protruding end 10 fixed at the top. The bottom of the hot press cylinder 8 has a port for the protruding end 10 to be inserted. The port is connected to the inside of the hot press cylinder 8. An electric heating wire is fixed inside the heating base 6. When the electric heating wire is energized, it generates heat to provide the heat required for hot pressing. When the hot press cylinder 8 and the protruding end 10 are completely separated, the heat can be quickly discharged.

[0062] Two hot press cylinders 8 are each fixed with a connecting block 7 on one side opposite to the other. The central tube 12 passes through the two connecting blocks 7 on the opposite side. The top two sides of the hot press cylinder 8 are elastically telescopically connected with intercepting plates 11. The conveying trough 9 is provided with baffles on both sides. The positions of the two intercepting plates 11 correspond to the positions of the two baffles, so as to prevent the material from falling from both sides when it slides down, and play a role in interception and protection.

Claims

1. A method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material, characterized in that: Includes the following steps: S1. Preparation of amorphous ribbons: The alloy raw materials are melted in a vacuum induction melting furnace, and the melt temperature is controlled at 1450-1600℃. S2. Amorphous ribbons are prepared by using a single-roller rapid quenching method with a roller speed of 15-40 m / s on the smelted raw materials. S3, Nanocrystallization Annealing: The amorphous ribbon is placed in an inert gas protected annealing furnace for annealing; S4. High-resistivity layer deposition: An insulating layer is deposited on the surface of the annealed amorphous ribbon using atomic layer deposition technology. S5. Composite structure assembly: Using a hot pressing device, multi-layer amorphous thin strips are hot pressed together; The hot pressing device includes two lower fixing blocks (14), with a central tube (12) at the top of each lower fixing block (14). Both ends of the central tube (12) are connected to a hot pressing cylinder (8). A heating base (6) is provided at the bottom of each hot pressing cylinder (8). A lower pressure plate (5) is raised and lowered inside the hot pressing cylinder (8). Multiple amorphous thin strips are stacked inside the hot press cylinder (8); Two air holes (13) are opened in the middle of the central tube (12), and the two air holes (13) are used to connect the gas transmission pipeline and the vacuum device respectively.

2. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 1, characterized in that: The two ends of the central tube (12) extend out of corresponding lower fixing blocks (14), and the bottom ends of the two lower fixing blocks (14) are fixed with a base plate (1). At least two hydraulic cylinders (2) are fixed on one side of the top of the base plate (1). Two hydraulic cylinders (2) are connected to a top plate (3) at their top ends. An upper fixing block (15) is fixed at the bottom of the top plate (3). The upper fixing block (15) and the lower fixing block (14) are positioned in opposite directions, and the upper fixing block (15) and the lower fixing block (14) have grooves on opposite sides that engage with the outer side of the central tube (12).

3. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 2, characterized in that: The top of the lower pressure plate (5) is connected to a fixing column (4), which is fixed to the top of the top plate (3); The heating base (6) has a protruding end (10) fixed at the top, and the bottom of the hot press cylinder (8) has a port for the protruding end (10) to be inserted. The port is connected to the inside of the hot press cylinder (8), and an electric heating wire is fixed inside the heating base (6).

4. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 1, characterized in that: A sealing gasket is fixed on the outside of the lower pressure plate (5), and the outside of the sealing gasket is in contact with the inside of the corresponding hot press cylinder (8).

5. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 4, characterized in that: Two lower fixing blocks (14) are each fixed with an electric push rod (16) on one side of each other. The top of each electric push rod (16) is fixed with a push plate. The top of each push plate is provided with a slot (17) corresponding to the outer arc of the central tube (12).

6. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 1, characterized in that: Two hot press cylinders (8) are each fixed with a connecting block (7) on one side opposite to each other, and the central tube (12) passes through the two connecting blocks (7) on the opposite side. Two connecting blocks (7) are fixed with a conveying groove (9) at one end away from the central tube (12), and the conveying groove (9) is set at an angle; The end of the conveying trough (9) away from the central tube (12) is inclined upward, and the end of the conveying trough (9) near the hot press cylinder (8) is flush with the top surface of the hot press cylinder (8). The end of the conveying trough (9) near the hot press cylinder (8) corresponds to the outer arc surface of the hot press cylinder (8).

7. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 6, characterized in that: The top of the hot press cylinder (8) is elastically telescopically connected with intercepting plates (11) on both sides, and the conveying groove (9) is provided with baffles on both sides. The positions of the two intercepting plates (11) correspond to the positions of the two baffles respectively.

8. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 1, characterized in that: The bottom of the pressure plate (5) is provided with a nozzle, and the top plate (3) is fixed with a spraying mechanism (18). The spraying mechanism (18) is connected to the nozzle through a pipe. The spraying mechanism (18) is used to spray Y2O3 anti-stick coating into the hot press cylinder (8).

9. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 1, characterized in that: The gas pipeline is used for argon gas.

10. The method for preparing a high resistivity amorphous nanocrystalline composite soft magnetic material according to claim 1, characterized in that: In the nanocrystalline annealing process, the amorphous ribbon is placed in an inert gas protected annealing furnace. The temperature is first increased to the first annealing temperature of 250-320℃ at a rate of 10-30℃ / min and held for 10-30 minutes. Then, the temperature is increased to the second annealing temperature of 380-450℃ at a rate of 5-15℃ / min and held for 5-60 minutes, while a 1-5T transverse static magnetic field is applied simultaneously.

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