Low-coercivity wiegand filament and preparation method thereof

Abstract

The invention provides a low-coercivity wiegand filament and a preparation method thereof. The wiegand filament comprises the following components in percentage by weight: 10 wt% to 15 wt% of Ni, 3 wt% to 7 wt% of Co, 2 wt% to 5 wt% of Al, 1 wt% to 4 wt% of Si, 1 wt% to 3 wt% of Mn, 0.5 wt% to 2 wt% of Ti, 2 wt% to 5 wt% of Al2O3, 0.2 wt% to 0.6 wt% of Nd and the balance of Fe and other inevitable impurities. The preparation method comprises the steps of raw material weighing, smelting, quenching, heat treatment and multi-stage drawing, and the magnetic performance is further optimized by applying a magnetic field in the process. Through the combination of the nanoscale aluminum oxide particles and the rare earth elements, the coercive force of the Wiegand filament is effectively reduced, meanwhile, the saturation magnetic induction intensity is improved, and the method is suitable for being applied to high-precision sensors and low-energy-consumption magnetic elements.

Description

Technical Field

[0001] The invention relates to the technical field of Wiegand wires, in particular to a low-coercivity Wiegand wire and a preparation method thereof. Background Art

[0002] With the rapid development of modern magnetic materials science, especially in high-tech fields such as electronic devices, sensors and motors, the demand for Wiegand wires has gradually increased. Wiegand wires are widely used due to their unique magnetic properties, especially in magnetic reversal and low-energy consumption applications. However, the performance of Wiegand wires is currently limited by the contradiction between the coercivity and magnetic permeability of the material. Traditional Wiegand wires are mainly composed of metal alloys. Although they can meet application requirements to a certain extent, their high coercivity often leads to increased energy loss and affects the response speed and sensitivity of the system. This limitation has prompted researchers to seek new composite materials to overcome the shortcomings of existing technologies in magnetic material performance and promote the development and application of new magnetic materials.

[0003] The current technical route mainly focuses on improving the performance of Wiegand wire by optimizing the metal alloy composition, controlling the processing technology and improving the annealing treatment. However, these methods are still not effective in reducing the coercive force and improving the magnetic permeability. Especially under dynamic magnetic field conditions, the magnetic properties of existing materials are often difficult to reach the ideal state and cannot meet the needs of high-precision sensors and fast response systems. Summary of the invention

[0004] The current technical route mainly focuses on improving the performance of Wiegand wire by optimizing the metal alloy composition, controlling the processing technology and improving the annealing treatment. However, these methods are still not effective in reducing the coercive force and improving the magnetic permeability. Especially under dynamic magnetic field conditions, the magnetic properties of existing materials are often difficult to reach the ideal state and cannot meet the needs of high-precision sensors and fast response systems.

[0005] The present application provides a low coercive force Wiegand wire, which comprises, by weight percentage: Ni 10wt% to 15wt%, Co 3wt% to 7wt%, Al 2wt% to 5wt%, Si 1wt% to 4wt%, Mn 1wt% to 3wt%, Ti 0.5wt% to 2wt%, Al 2 O 3 2wt% to 5wt%, Nd 0.2wt to 0.6wt%, and the balance Fe and other inevitable impurities.

[0006] As a preferred technical solution for low coercive force Wiegand wire, the following components are included in weight percentage: Ni 13wt%, Co 4wt%, Al 3wt%, Si 4wt%, Mn 2wt%, Ti 0.5wt%, Al 2 O3 3wt%, Nd 0.4wt%, and the balance Fe and other inevitable impurities.

[0007] In addition, the present application provides a method for preparing low coercive force Wiegand wire, comprising the following preparation steps: S1.According to the designed composition ratio, accurately weigh Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Al alloy powder, Fe-Mn alloy powder, Fe-Ti alloy powder, Si powder, Al 2 O 3 powder and Fe powder; S2. The weighed powders in step S1 are uniformly mixed in a planetary ball mill according to the proportion, and the mixed powders are melted in a vacuum induction furnace at a temperature set at 1450°C-1600°C for 1-2 hours; S3. The molten metal is quickly poured into a mold preheated to 300°C and cooled therein for 1 to 2 minutes; S4. The quenched alloy billet is heated to 600°C-800°C and maintained at this temperature for 4 hours, and then naturally cooled to room temperature; S5. The heat-treated billet is preheated in a heating furnace, and then the preheated billet is introduced into a drawing machine and stretched by applying a uniform tensile force; S6. Pickling the drawn Wiegand wire to remove the surface oxide layer, the pickling temperature is set at 50℃-60℃, the soaking time is 15 minutes, using 5wt%-10wt% sulfuric acid solution, and then sandblasting is performed.

[0008] As a preferred technical solution for the preparation of a low coercive force Wiegand wire, the Al 2 O 3 The particle size of the powder ranges from 100 nm to 300 nm.

[0009] It should be noted that, firstly, the surface area of ​​nano-sized particles is relatively large, which can form more interfaces in the alloy. These interfaces can inhibit the formation and movement of magnetic domains, thereby reducing the coercive force. Secondly, smaller particles promote the refinement of grains in the alloy. The refined grains can effectively hinder the movement of magnetic domains, further reducing the coercive force of the material. In addition, Al 2 O 3 As an insulating material, it acts as an isolator in the alloy, which can reduce magnetic coupling and alleviate hysteresis. Finally, Al 2 O 3 The uniform distribution and good dispersion of powder can improve the overall stability of the material and ensure the consistency and reliability of magnetic properties. Therefore, reasonable control of Al 2 O 3The particle size of the powder can not only improve the comprehensive properties of the alloy, but also significantly reduce its coercivity.

[0010] As a preferred technical solution for a method for preparing low coercive force Wiegand wire, when applying a magnetic field during the drawing stage, a constant magnetic field of 100 mT to 500 mT is used, and the direction of the magnetic field is consistent with the drawing direction.

[0011] It should be noted that the external magnetic field and its direction have a profound impact on the magnetic induction intensity and coercivity of the material. When an external magnetic field is applied during the processing of magnetic materials, the magnetic domains tend to rearrange along the direction of the external magnetic field. This orderly magnetic domain orientation enhances the net magnetic moment of the material, thereby increasing the magnetic induction intensity. At the same time, the external magnetic field reduces the energy barrier of the movement of the magnetic domain wall, making it easier for the magnetic domain wall to move, reducing internal stress and defects, and thus reducing the coercivity. In particular, when the direction of the external magnetic field is consistent with the processing direction, such as parallel to the pulling direction, it can promote the preferential orientation of grains and magnetic domains, and ultimately achieve the optimization of magnetic properties.

[0012] As a preferred technical solution of a method for preparing a low coercive force Wiegand wire, the step S5 specifically comprises the following steps: In the first stage of drawing, the alloy billet is heated to 800°C to 1000°C. Within this temperature range, the plasticity of the material is enhanced, the yield strength is reduced, and the material is more easily deformed during the drawing process. The drawing rate of 0.5 mm / s to 2 mm / s can effectively control the deformation rate of the material and avoid excessive stress concentration, thereby improving the uniformity and accuracy of the initial forming. After the drawing is completed, it is gradually cooled to room temperature, which helps to fix the microstructure of the alloy and improve its mechanical properties. In the second stage of drawing, the material is heated again to 600°C to 800°C. At this time, the material still maintains good plasticity and can further reduce the diameter to 80%-90% of the target at a drawing rate of 2 mm / s to 5 mm / s. The heating temperature at this stage is relatively low, which helps to reduce the impact of heat treatment on the material, maintain appropriate hardness and toughness, and avoid excessive embrittlement. After cooling to room temperature, the microstructure is further stabilized, and the magnetic properties of the material are enhanced. Finally, in the final drawing stage, the alloy billet is heated again to 600°C to 800°C, and the final forming is carried out after selecting a suitable drawing die. The temperature setting at this stage ensures the plasticity of the material. The use of a higher drawing rate (2 mm / s to 5 mm / s) can effectively shorten the drawing time and improve production efficiency. After completion, it is gradually cooled to room temperature to ensure the dimensional accuracy and performance stability of the final product. Through step-by-step drawing, not only the microstructure of the material is optimized, but also the comprehensive performance of the alloy is improved, laying a good foundation for the preparation of the final low coercive force Wiegand wire.

[0013] Beneficial effects of the present invention: 1. The mechanism of iron (Fe) in low coercive force Wiegand wire is mainly reflected in its role as the main component of the alloy, providing basic magnetic and mechanical strength. Iron has excellent magnetic permeability and can effectively form and maintain magnetic domain structure, thereby improving the saturation magnetic induction intensity of the material. This strong magnetism enables iron to enhance the overall magnetic properties when combined with other alloy elements (such as nickel, cobalt, etc.). In addition, when iron is combined with elements such as aluminum, it can form a stable oxide layer, which improves the oxidation resistance and corrosion resistance of the alloy. At the same time, the low cost of iron makes it an economical choice for manufacturing low coercive force Wiegand wire, further reducing the production cost of the material; 2. The mechanism of nickel (Ni) in low coercive force Wiegand wire is mainly reflected in its enhancement of the magnetic and mechanical properties of the material. As an important alloying element, nickel has good corrosion resistance and toughness, which can significantly improve the overall durability of the alloy. In terms of magnetic properties, nickel can optimize the magnetic domain structure and promote close coupling between magnetic domains, thereby reducing the movement resistance of the magnetic domain wall and reducing the coercive force. In addition, the alloying interaction formed by nickel and other elements (such as cobalt and aluminum) in the alloy can improve the saturation magnetic induction intensity of the alloy, so that the material exhibits better magnetic characteristics during application. At the same time, the addition of nickel can also improve the thermal stability of the material and ensure excellent performance in high temperature environments. In summary, the weight percentage of Ni in the Wiegand wire prepared in this application is controlled at 10wt% to 15wt%; 3. The mechanism of cobalt (Co) in low coercive force Wiegand wire is mainly reflected in its enhancement of the magnetic properties of the material and improvement of the mechanical strength of the alloy. Cobalt has a high saturation magnetic induction intensity, which can effectively improve the magnetic permeability of the alloy and enhance its overall magnetic properties. In addition, cobalt can optimize the arrangement and stability of magnetic domains, thereby reducing hysteresis loss, which is crucial to reducing coercive force. The addition of cobalt can also improve the corrosion resistance and wear resistance of the alloy, making the material perform better in harsh environments. Through the synergistic effect with elements such as nickel and iron, cobalt can form a stable magnetic interaction, further enhancing the magnetic properties of the material. In addition, the presence of cobalt helps to adjust the crystal structure of the alloy, promote grain refinement, and reduce internal defects and stress concentration. In summary, the weight percentage of Co in the Wiegand wire prepared in this application is controlled at 3wt% to 7wt%; 4. The mechanism of aluminum (Al) in low coercive force Wiegand wire is mainly reflected in its improvement of the oxidation resistance and mechanical properties of the alloy. The addition of aluminum can form a protective oxide film, improve the corrosion resistance of the alloy, and thus extend the service life of the material. In addition, the presence of aluminum helps to promote grain refinement, enhance the toughness and strength of the material, and reduce the risk of failure due to brittleness. Aluminum can also optimize the magnetism of the alloy, improve the magnetic properties by reducing the magnetic defects and grain boundary resistance inside the material, thereby reducing the coercive force. The interaction between aluminum and other alloying elements (such as nickel and cobalt) can form a stable alloy phase, further improving the overall magnetic properties. In summary, the weight percentage of Al in the preparation of Wiegand wire in this application is controlled at 2wt% to 5wt%; 5. The mechanism of silicon (Si) in low coercive force Wiegand wire is mainly reflected in its improvement of the electrical conductivity and high temperature resistance of the alloy. The addition of silicon can improve the magnetic permeability of the material and reduce the hysteresis loss caused by current loss, thereby effectively reducing the coercive force. In addition, silicon can optimize the microstructure of the alloy, promote grain refinement, reduce the influence of magnetic defects and grain boundaries, and thus improve the overall magnetic properties of the material. The presence of silicon in the alloy can also improve its oxidation resistance, enhance the stability of the alloy in a high temperature environment, and reduce the performance degradation caused by high temperature. Through the interaction with elements such as iron, nickel and cobalt, silicon can promote the formation of a more uniform alloy phase, thereby optimizing the performance of the material. In summary, the weight percentage of Si in the Wiegand wire prepared in this application is controlled at 2wt% to 5wt%; 6. The mechanism of manganese (Mn) in low coercive force Wiegand wire is mainly reflected in its improvement of alloy strength and magnetic properties. The addition of manganese can effectively improve the oxidation resistance and corrosion resistance of the alloy and reduce the performance degradation of the material in harsh environments. In addition, manganese can promote grain refinement and reduce internal stress and magnetic defects by reducing grain size, thereby optimizing the magnetic permeability of the material and reducing coercive force. Manganese can also form a stable alloy phase with elements such as iron, nickel and cobalt in the alloy, enhance magnetic interaction, and further improve the saturation magnetic induction intensity and overall magnetic properties of the material. At the same time, the presence of manganese helps to reduce the movement resistance of the magnetic domain wall, making the material more sensitive to the magnetic field. In summary, the weight percentage of Mn in the Wiegand wire prepared in this application is controlled at 1wt% to 3wt%; 7. The mechanism of titanium (Ti) in low coercive force Wiegand wire is mainly reflected in its enhancement of alloy strength and improvement of corrosion resistance. The addition of titanium can effectively improve the material's oxidation resistance and form a stable titanium oxide layer, thereby protecting the alloy from environmental factors. In addition, titanium has high strength and stiffness, which can improve the overall mechanical properties of the alloy and enhance the stability of the material under load. Titanium also plays a role in refining grains in the alloy, reducing defects and stress concentration inside the material, thereby optimizing magnetic properties and reducing coercive force. At the same time, the presence of titanium helps to improve the thermal stability of the alloy, so that the material maintains good performance in high-temperature applications. In summary, the weight percentage of Ti in the Wiegand wire prepared in this application is controlled at 0.5wt% to 2wt%; 8. Alumina (Al 2 O 3 ) in reducing coercivity and increasing saturation magnetic induction intensity are mainly reflected in the following aspects. First, nanoscale Al 2 O 3 The particles can be evenly distributed in the alloy matrix to form a large number of interfaces. Due to the existence of these interfaces, the movement of the magnetic domain wall will be hindered, which will play a pinning effect, thereby effectively reducing the movement range and energy loss of the magnetic domain wall, thereby reducing the coercive force. In addition, Al 2 O 3 The introduction of particles can refine the grain structure of the alloy. The fine grains increase the number of grain boundaries, further strengthening the pinning effect of grain boundaries on the magnetic domain walls, making it more difficult for the magnetic domain walls to move. This not only helps to reduce the coercive force, but also improves the stability of the alloy under an external magnetic field. On the other hand, Al 2 O 3 The dispersed phase effect can optimize the microstructure of the alloy, reduce the generation and aggregation of internal defects, and reduce the internal stress of the material, which helps to reduce the hysteresis phenomenon and enable the material to reach the magnetic saturation state under a lower external magnetic field, thereby increasing the saturation magnetic induction intensity. 2 O 3 The particles can also improve the mechanical strength and thermal stability of the material. This strengthening effect makes the alloy more stable under high magnetic fields and can maintain high magnetic properties without microstructural collapse. In summary, the present invention prepares Wiegand wire Al 2 O 3 The weight percentage is controlled at 2wt% to 5wt%, and the particle size ranges from 100 nm to 500 nm; 9. The mechanism of cerium (Nd) in reducing the coercive force of the alloy is mainly reflected in its ability to enhance magnetic interaction and improve the microstructure. Nd has high magnetic permeability and good magnetic stability. Its addition can increase the saturation magnetic induction intensity of the alloy, making the arrangement of magnetic domains more orderly. This orderly arrangement reduces hysteresis loss, thereby effectively reducing coercive force. In addition, the presence of Nd promotes the refinement of alloy grains, reduces internal defects and stress concentration, and further optimizes the magnetic properties of the material. At the same time, Nd can form a stable alloy phase with other alloy elements (such as iron, nickel and cobalt), improve the overall strength and toughness of the alloy, and reduce the magnetic loss caused by changes in the external magnetic field; In summary, the weight percentage of Nd in the preparation of Wiegand wire in this application is controlled at 0.2wt% to 0.6wt%; 10. The synergistic effect between nickel (Ni), cobalt (Co) and aluminum (Al) plays an important role in low coercivity and high saturation magnetic induction intensity Wiegand wire. Nickel improves the saturation magnetic induction intensity and magnetic permeability of the alloy, forms a stable magnetic phase with other elements (such as cerium Nd), and enhances the orderly arrangement of magnetic domains, thereby reducing hysteresis loss and reducing coercivity. At the same time, as a high-quality soft magnetic material, the introduction of cobalt not only improves the magnetic permeability and saturation magnetic induction intensity of the alloy, but also promotes the formation of uniform magnetic phases together with nickel, enhances the stability of magnetic domains, and makes the material more sensitive to external magnetic fields. Aluminum plays a vital role in this process. Its enhanced oxidation resistance and improved mechanical properties work synergistically with nickel and cobalt to promote grain refinement, reduce internal defects, and thus optimize the microstructure of the alloy. In addition, the presence of aluminum also improves the thermal stability of the alloy, allowing the material to maintain good magnetic properties under a variety of environmental conditions. In summary, the synergistic effect between nickel, cobalt and aluminum ultimately achieves the goal of reducing coercivity by improving the microstructure and magnetic properties of the alloy, ensuring the reliability and effectiveness of Wiegand wire in high-performance applications; BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 This is an experimental data diagram of the Wiegand silk prepared in Example 5; DETAILED DESCRIPTION

[0015] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0016] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0017] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0018] Embodiment 1 provides a low coercivity Wiegand wire and a preparation method, wherein: The components of Wiegand wire include Ni 15wt%, Co 3wt%, Al 3wt%, Si 3wt%, Mn1wt%, Ti 2wt%, Al 2 O 3 2wt%, Nd 0.6wt%, and the balance is Fe and other inevitable impurities.

[0019] The method for preparing low coercive force Wiegand wire comprises the following preparation steps: S1.According to the designed composition ratio, accurately weigh Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Al alloy powder, Fe-Mn alloy powder, Fe-Ti alloy powder, Si powder, Al 2 O 3 powder and Fe powder; among them, Al 2 O 3 The particle size of the powder ranges from 100 nm to 300 nm; S2. The weighed powders in step S1 are uniformly mixed in a planetary ball mill according to the proportion, and the mixed powders are melted in a vacuum induction furnace at a temperature set at 1450°C for 2 hours; S3. The molten metal is quickly poured into a mold preheated to 300°C and cooled therein for 2 minutes; S4. The quenched alloy billet is heated to 600°C and maintained at this temperature for 4 hours, and then naturally cooled to room temperature; S5. heating the alloy billet to 800°C, performing preliminary drawing at a drawing rate of 0.5 mm / s, drawing the alloy billet to 60% of the target diameter, and gradually cooling the first drawn alloy billet to room temperature after completing the first stage of drawing; The alloy billet drawn for the first time after cooling was heated again, the temperature was set at 600°C, and the second stage drawing was carried out at a drawing rate of 5 mm / s, and the alloy billet drawn for the first time was drawn to 80% of the target diameter. After the second stage drawing was completed, the alloy billet drawn for the second time was gradually cooled to room temperature; The alloy billet drawn for the second time after cooling was heated again, the temperature was set at 800°C, a drawing die was selected, and a final drawing was performed at a drawing rate of 2 mm / s. The alloy billet drawn for the second time was drawn to a target diameter. After the final drawing was completed, the alloy billet drawn for the final time was gradually cooled to room temperature. When a magnetic field was applied during the drawing stage, a constant magnetic field of 100 mT was used, and the direction of the magnetic field was consistent with the drawing direction. S6. Pickling the drawn Wiegand wire to remove the surface oxide layer, the pickling temperature is set at 50°C, the soaking time is 15 minutes, and a 5wt% sulfuric acid solution is used, followed by sandblasting.

[0020] Embodiment 2 provides a low coercive force Wiegand wire and a preparation method, wherein: The components of Wiegand wire include Ni 13wt%, Co 4wt%, Al 3wt%, Si 4wt%, Mn2wt%, Ti 0.5wt%, Al 2 O 3 3wt%, Nd 0.4wt%, and the balance Fe and other inevitable impurities.

[0021] The method for preparing low coercive force Wiegand wire comprises the following preparation steps: S1.According to the designed composition ratio, accurately weigh Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Al alloy powder, Fe-Mn alloy powder, Fe-Ti alloy powder, Si powder, Al 2 O 3 powder and Fe powder; among them, Al 2 O 3 The particle size of the powder ranges from 200 nm to 500 nm; S2. The weighed powders in step S1 are uniformly mixed in a planetary ball mill according to the proportion, and the mixed powders are melted in a vacuum induction furnace at a temperature set at 1600°C for 1 hour; S3. The molten metal is quickly poured into a mold preheated to 300°C and cooled therein for 1 minute; S4. The quenched alloy billet is heated to 800°C and maintained at this temperature for 4 hours, and then naturally cooled to room temperature; S5. heating the alloy billet to 1000°C, performing preliminary drawing at a drawing rate of 2 mm / s, drawing the alloy billet to 70% of the target diameter, and gradually cooling the first drawn alloy billet to room temperature after completing the first stage of drawing; The cooled alloy billet drawn for the first time is heated again, the temperature is set at 800°C, and the second stage drawing is performed at a drawing rate of 2 mm / s, and the alloy billet drawn for the first time is drawn to 90% of the target diameter. After the second stage drawing is completed, the alloy billet drawn for the second time is gradually cooled to room temperature; The alloy billet drawn for the second time after cooling was heated again, the temperature was set at 600°C, a drawing die was selected, and the final drawing was performed at a drawing rate of 5 mm / s, and the alloy billet drawn for the second time was drawn to a target diameter. After the final drawing was completed, the alloy billet drawn for the final time was gradually cooled to room temperature; when a magnetic field was applied during the drawing stage, a constant magnetic field of 500 mT was used, and the direction of the magnetic field was consistent with the drawing direction; S6. Pickling the drawn Wiegand wire to remove the surface oxide layer, the pickling temperature is set at 60°C, the soaking time is 15 minutes, and a 10wt% sulfuric acid solution is used, followed by sandblasting.

[0022] Embodiment 3 provides a low coercive force Wiegand wire and a preparation method, wherein: The components of Wiegand wire include Ni 10wt%, Co 7wt%, Al 5wt%, Si 3wt%, Mn 3wt%, Ti 1wt%, Al 2 O 3 5wt%, Nd 0.2wt%, and the balance Fe and other inevitable impurities.

[0023] The method for preparing low coercive force Wiegand wire comprises the following preparation steps: S1.According to the designed composition ratio, accurately weigh Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Al alloy powder, Fe-Mn alloy powder, Fe-Ti alloy powder, Si powder, Al 2 O 3 powder and Fe powder; among them, Al 2 O 3 The particle size of the powder ranges from 100 nm to 400 nm; S2. The weighed powders in step S1 are uniformly mixed in a planetary ball mill according to the proportion, and the mixed powders are melted in a vacuum induction furnace at a temperature set at 1500°C for 1 hour; S3. The molten metal is quickly poured into a mold preheated to 300°C and cooled therein for 1 minute; S4. The quenched alloy billet is heated to 700°C and maintained at this temperature for 4 hours, and then naturally cooled to room temperature; S5. heating the alloy billet to 1000°C, performing preliminary drawing at a drawing rate of 2 mm / s, drawing the alloy billet to 70% of the target diameter, and gradually cooling the first drawn alloy billet to room temperature after completing the first stage of drawing; The alloy billet drawn for the first time after cooling was heated again, the temperature was set at 700°C, and the second stage drawing was performed at a drawing rate of 4 mm / s, and the alloy billet drawn for the first time was drawn to 85% of the target diameter. After the second stage drawing was completed, the alloy billet drawn for the second time was gradually cooled to room temperature; The alloy billet drawn for the second time after cooling was heated again, the temperature was set at 600°C, a drawing die was selected, and the final drawing was performed at a drawing rate of 5 mm / s, and the alloy billet drawn for the second time was drawn to a target diameter. After the final drawing was completed, the alloy billet drawn for the final time was gradually cooled to room temperature; when the magnetic field was applied in the drawing stage, a constant magnetic field of 100 mT was used, and the direction of the magnetic field was consistent with the drawing direction; S6. Pickling the drawn Wiegand wire to remove the surface oxide layer, the pickling temperature is set at 60°C, the soaking time is 15 minutes, using 8wt% sulfuric acid solution, followed by sandblasting.

[0024] Embodiment 4 provides a low coercivity Wiegand wire and a preparation method, wherein: The components of Wiegand wire include Ni 13wt%, Co 7wt%, Al 2wt%, Si 1wt%, Mn2wt%, Ti 1wt%, Al 2 O 3 3wt%, Nd 0.6wt%, and the balance Fe and other inevitable impurities.

[0025] The method for preparing low coercive force Wiegand wire comprises the following preparation steps: S1.According to the designed composition ratio, accurately weigh Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Al alloy powder, Fe-Mn alloy powder, Fe-Ti alloy powder, Si powder, Al 2 O 3 powder and Fe powder; among them, Al 2 O 3 The particle size of the powder ranges from 200 nm to 400 nm; S2. The weighed powders in step S1 are uniformly mixed in a planetary ball mill according to the proportion, and the mixed powders are melted in a vacuum induction furnace at a temperature set at 1600°C for 2 hours; S3. The molten metal is quickly poured into a mold preheated to 300°C and cooled therein for 1 minute; S4. The quenched alloy billet is heated to 800°C and maintained at this temperature for 4 hours, and then naturally cooled to room temperature; S5. heating the alloy billet to 1000°C, performing preliminary drawing at a drawing rate of 1 mm / s, drawing the alloy billet to 60% of the target diameter, and gradually cooling the first drawn alloy billet to room temperature after completing the first stage of drawing; The cooled alloy billet drawn for the first time is heated again, the temperature is set at 800°C, and the second stage drawing is performed at a drawing rate of 4 mm / s, and the alloy billet drawn for the first time is drawn to 80% of the target diameter. After the second stage drawing is completed, the alloy billet drawn for the second time is gradually cooled to room temperature; The alloy billet drawn for the second time after cooling was heated again, the temperature was set at 600°C, a drawing die was selected, and a final drawing was performed at a drawing rate of 5 mm / s, and the alloy billet drawn for the second time was drawn to a target diameter. After the final drawing was completed, the alloy billet drawn for the final time was gradually cooled to room temperature; when a magnetic field was applied during the drawing stage, a constant magnetic field of 400 mT was used, and the direction of the magnetic field was consistent with the drawing direction; S6. Pickling the drawn Wiegand wire to remove the surface oxide layer, the pickling temperature is set at 60°C, the soaking time is 15 minutes, and a 10wt% sulfuric acid solution is used, followed by sandblasting.

[0026] Embodiment 5 provides a low coercive force Wiegand wire and a preparation method, wherein: The components of Wiegand wire include Ni 12wt%, Co 6wt%, Al 5wt%, Si 2wt%, Mn 3wt%, Ti 1wt%, Al 2 O 3 4wt%, Nd 0.6wt%, and the balance Fe and other inevitable impurities.

[0027] The method for preparing low coercive force Wiegand wire comprises the following preparation steps: S1.According to the designed composition ratio, accurately weigh Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Al alloy powder, Fe-Mn alloy powder, Fe-Ti alloy powder, Si powder, Al 2 O 3 powder and Fe powder; among them, Al 2 O 3 The particle size of the powder ranges from 200 nm to 400 nm; S2. The weighed powders in step S1 are uniformly mixed in a planetary ball mill according to the proportion, and the mixed powders are melted in a vacuum induction furnace at a temperature set at 1500°C for 2 hours; S3. The molten metal is quickly poured into a mold preheated to 300°C and cooled therein for 1 minute; S4. The quenched alloy billet was heated to 200°C, 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, and 1000°C, and maintained at the temperature for 4 hours, and then naturally cooled to room temperature; S5. heating the alloy billet to 800°C, performing preliminary drawing at a drawing rate of 1 mm / s, drawing the alloy billet to 65% of the target diameter, and gradually cooling the first drawn alloy billet to room temperature after completing the first stage of drawing; The cooled alloy billet drawn for the first time is heated again, the temperature is set at 800°C, and the second stage drawing is performed at a drawing rate of 4 mm / s, and the alloy billet drawn for the first time is drawn to 80% of the target diameter. After the second stage drawing is completed, the alloy billet drawn for the second time is gradually cooled to room temperature; The alloy billet drawn for the second time after cooling is heated again, the temperature is set at 600°C, a drawing die is selected, and a final drawing is performed at a drawing rate of 3 mm / s, and the alloy billet drawn for the second time is drawn to a target diameter. After the final drawing is completed, the alloy billet drawn for the final time is gradually cooled to room temperature; when a magnetic field is applied in the drawing stage, a constant magnetic field of 400 mT is used, and the direction of the magnetic field is consistent with the drawing direction; S6. Pickling the drawn Wiegand wire to remove the surface oxide layer, the pickling temperature is set at 60°C, the soaking time is 15 minutes, and a 10wt% sulfuric acid solution is used, followed by sandblasting.

[0028] Comparative Example 1 The difference between this comparative example and Example 2 is that Al 2 O 3 The particle size of the powder ranges from 500 um to 1000 um;

[0029] Comparative Example 2 The difference between this control example and Example 2 is that the Nd powder is replaced by an equal mass of Fe powder;

[0030] Comparative Example 3 The difference between this control example and Example 2 is that no magnetic field is applied during the drawing stage;

[0031] Comparative Example 4 The difference between this control example and Example 2 is that a constant magnetic field of 500 mT is applied during the drawing stage, and the direction of the magnetic field is perpendicular to the drawing direction;

[0032] Comparative Example 5 The difference between this control example and Example 2 is that the Al powder is replaced by an equal mass of Fe powder;

[0033] Comparative Example 6 The difference between this control example and Example 2 is that the Co powder is replaced by an equal mass of Fe powder;

[0034] Comparative Example 7 The difference between this control example and Example 2 is that the Ni powder is replaced by an equal mass of Fe powder;

[0035] Table 1: Wiegand silk composition ratio (wt%) of Examples 1 to 4 and Comparative Examples 1 to 7 project Ni Co Al Si Mn Ti <![CDATA[Al 2 THE 3 ]]> Nd Example 1 15 3 3 3 1 2 2 0.6 Example 2 13 4 3 4 2 0.5 3 0.4 Example 3 10 7 5 3 3 1 5 0.2 Example 4 13 7 2 1 2 1 3 0.6 Example 5 12 6 5 2 3 1 4 0.6 Comparative Example 1 13 4 3 4 2 0.5 3 0.4 Comparative Example 2 13.4 4 3 4 2 0.5 3 0 Comparative Example 3 13 4 3 4 2 0.5 3 0.4 Comparative Example 4 13 4 3 4 2 0.5 3 0.4 Comparative Example 5 13 4 0 4 2 0.5 3 0.4 Comparative Example 6 13 0 3 4 2 0.5 3 0.4 Comparative Example 7 0 4 3 4 2 0.5 3 0.4

[0036] Specific test methods for coercivity (Hc) and saturation magnetic induction (Bs): During the test, the sample is first prepared into an appropriate shape and size to ensure compatibility with the test equipment. The sample is fixed in the sample holder of the VSM and tested at a constant temperature. A gradually increasing external magnetic field is applied, starting from zero until it reaches the set maximum value, and then gradually reduced to a negative value. Through this process, the magnetic induction intensity of the sample under different magnetic field strengths can be recorded.

[0037] By analyzing the relationship curve between magnetic induction intensity and external magnetic field intensity, the saturation magnetic induction intensity (Bs) can be determined, which is the maximum magnetic induction intensity that the sample can reach under the external magnetic field. At the same time, by observing the magnetic response of the sample when the magnetic field direction is reversed, the coercive force (Hc) can be determined, that is, the reverse magnetic field intensity that needs to be applied to the material after the external magnetic field is removed in order to restore its magnetism to zero.

[0038] Table 2 is the data of Examples 1 to 4 and Comparative Examples 1 to 7 project Saturation magnetic flux density (Bs) / (emu / g) Coercivity (Hc) / (Oe) Example 1 182 6.8 Example 2 174 8.2 Example 3 175 7.5 Example 4 189 6.1 Comparative Example 1 142 28.4 Comparative Example 2 105 34.2 Comparative Example 3 104 33.4 Comparative Example 4 95 36.7 Comparative Example 5 108 32.4 Comparative Example 6 99 34.6 Comparative Example 7 97 35.4

[0039] It can be seen from Examples 1 to 4 and Table 2 that the saturation magnetic flux density of Examples 1 to 4 ranges from 174 emu / g to 189 emu / g, and the coercive force of Examples 1 to 4 ranges from 6.1 Oe to 8.2 Oe. The preparation process and composition of the present application can be used to prepare Wiegand wires with low coercive force while maintaining high saturation magnetic flux density.

[0040] Combining Example 2, Comparative Example 1 and Table 2, it can be seen that there are significant differences in saturation magnetic flux density and coercive force between Example 2 and Comparative Example 1. The saturation magnetic flux density of Example 2 is 174 emu / g and the coercive force is 8.2 Oe, while the saturation magnetic flux density of Comparative Example 1 is only 142 emu / g and the coercive force is as high as 28.4 Oe. 2 O 3 The particles can be evenly distributed in the alloy matrix to form a large number of interfaces. Due to the existence of these interfaces, the movement of the magnetic domain wall will be hindered, which will play a pinning effect, thereby effectively reducing the movement range and energy loss of the magnetic domain wall, thereby reducing the coercive force. In addition, Al 2 O 3 The introduction of particles can refine the grain structure of the alloy. The fine grains increase the number of grain boundaries, which further strengthens the pinning effect of the grain boundaries on the magnetic domain walls, making it more difficult for the magnetic domain walls to move. This not only helps to reduce the coercive force, but also improves the stability of the alloy under an external magnetic field. On the other hand, Al 2 O 3 The dispersed phase effect can optimize the microstructure of the alloy, reduce the generation and aggregation of internal defects, and reduce the internal stress of the material, which helps to reduce hysteresis and enable the material to reach magnetic saturation under a lower external magnetic field, thereby increasing the saturation magnetic induction intensity.

[0041] Combining Example 2, Control Example 2 and Table 2, it can be seen that there are significant differences in saturation magnetic induction intensity and coercive force between Example 2 and Control Example 2. The saturation magnetic induction intensity of Example 2 is 174 emu / g and the coercive force is 8.2 Oe, while the saturation magnetic induction intensity of Control Example 2 is only 105 emu / g, and the coercive force is as high as 34.2 Oe. Nd has high magnetic permeability and good magnetic stability. Its addition can increase the saturation magnetic induction intensity of the alloy and make the arrangement of magnetic domains more orderly. This orderly arrangement reduces hysteresis loss, thereby effectively reducing coercive force.

[0042] Combining Example 2, Comparative Examples 3 to 4 and Table 2, it can be seen that there are significant differences in saturation magnetic induction and coercive force between Example 2 and Comparative Examples 2 to 3. The saturation magnetic induction of Example 2 is 174 emu / g and the coercive force is 8.2 Oe, while the saturation magnetic induction of Comparative Example 3 is only 104 emu / g and the coercive force is as high as 33.4 Oe. The saturation magnetic induction of Comparative Example 4 is only 95 emu / g and the coercive force is as high as 36.7 Oe. When an external magnetic field is applied, the magnetic domains tend to rearrange along the direction of the magnetic field under the action of the magnetic field force. This orderly magnetic domain orientation makes the magnetic moment inside the material more consistent and enhances the magnetic induction intensity. When the direction of the magnetic field is consistent with the processing direction (such as the pulling direction), this effect is more significant because the magnetic domains are more likely to reorient in accordance with the external magnetic field. At the same time, the external magnetic field reduces the energy barrier of the magnetic domain wall, makes the magnetic domain wall move more easily, reduces the accumulation of internal stress and defects, and thus reduces the coercive force of the material.

[0043] Combining Example 2, Comparative Examples 5 to 7 and Table 2, it can be seen that there are significant differences in saturation magnetic flux density and coercive force between Example 2 and Comparative Examples 5 to 7. The saturation magnetic flux density of Example 2 is 174 emu / g and the coercive force is 8.2 Oe, while the saturation magnetic flux density of Comparative Example 5 is only 108 emu / g and the coercive force is as high as 32.4 Oe, the saturation magnetic flux density of Comparative Example 6 is only 99 emu / g and the coercive force is as high as 34.6 Oe, and the saturation magnetic flux density of Comparative Example 7 is only 97 emu / g and the coercive force is as high as 35.4 Oe. The synergistic effect between nickel (Ni), cobalt (Co) and aluminum (Al) plays an important role in the Wiegand wire with low coercive force and high saturation magnetic flux density. Nickel has good magnetic permeability and toughness, can optimize the magnetic domain structure, and promote close coupling between magnetic domains; cobalt has high saturation magnetization, and forms a stable magnetic phase with nickel, enhances the orderly arrangement of magnetic domains, and thus reduces hysteresis loss. The addition of aluminum helps to refine the grain structure, reduce internal defects, and form a protective oxide film to improve the oxidation resistance and corrosion resistance of the alloy. Aluminum also interacts with nickel and cobalt to further optimize the microstructure of the alloy. The synergistic effect of the three deeply improves the magnetic properties of the material, ultimately achieving the goal of low coercivity and high saturation magnetic induction intensity.

[0044] Combined with Example 5 and Figure 1It can be seen that when the heat treatment temperature is in the range of 600℃ to 800℃, the coercivity of the Wiegand wire is the lowest, the saturation magnetic induction intensity is the highest, and the magnetic properties are the best. In this temperature range, the grain size is moderate, the number of grain boundaries is appropriate, the internal stress and defects are effectively eliminated, and the magnetic phase is fully formed and evenly distributed. In this way, the movement of the magnetic domain wall is subject to moderate pinning, which is easy to reverse and not easy to be over-pinned, achieving low coercivity. At the same time, the optimization of the magnetic phase improves the saturation magnetic induction intensity; when the heat treatment temperature is too high, the grains grow excessively, the grain boundaries are reduced, the pinning effect of the magnetic domain wall is weakened, the coercivity increases, the elements are segregated and the non-magnetic phase is formed, the saturation magnetic induction intensity decreases, and the internal defects and elements are lost, further weakening the magnetic properties; when the heat treatment temperature is too low, the internal stress and defects cannot be eliminated, the magnetic domain wall is pinned, the coercivity increases, the favorable magnetic phase cannot be fully formed, the saturation magnetic induction intensity decreases, the diffusion of magnetic elements is restricted, and the magnetic phase is unevenly distributed.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low coercive force Wiegand wire, characterized in that: In terms of weight percentage, it includes: Ni 10wt% to 15wt%, Co 3wt% to 7wt%, Al 2wt% to 5wt%, Si 1wt% to 4wt%, Mn 1wt% to 3wt%, Ti 0.5wt% to 2wt%, Al2O32wt% to 5wt%, Nd 0.2wt to 0.6wt%, and the balance is Fe and other inevitable impurities.

2. The low coercive force Wiegand wire according to claim 1, characterized in that: In terms of weight percentage, it includes: Ni 13wt%, Co 4wt%, Al 3wt%, Si 4wt%, Mn 2wt%, Ti 0.5wt%, Al2O3 3wt%, Nd 0.4wt%, and the balance is Fe and other inevitable impurities.

3. The low coercive force Wiegand wire according to claim 1, characterized in that: The alloy comprises, in weight percentage: Ni 15wt%, Co 3wt%, Al 3wt%, Si 3wt%, Mn 1wt%, Ti 2wt%, Al2O3 2wt%, Nd 0.6wt%, and the balance is Fe and other inevitable impurities.

4. The low coercive force Wiegand wire according to claim 1, characterized in that: The composition includes, in weight percentage, Ni 10wt%, Co 7wt%, Al 5wt%, Si 3wt%, Mn 3wt%, Ti 1wt%, Al2O3 5wt%, Nd 0.2wt%, and the balance is Fe and other inevitable impurities.

5. The low coercive force Wiegand wire according to claim 1, characterized in that: In terms of weight percentage, it includes: Ni 13wt%, Co 7wt%, Al 2wt%, Si 1wt%, Mn 2wt%, Ti 1wt%, Al2O3 3wt%, Nd 0.6wt%, and the balance is Fe and other inevitable impurities.

6. The method for preparing low coercive force Wiegand wire according to claim 1, characterized in that: The method comprises the following preparation steps: S1. According to the designed composition ratio, accurately weigh Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Al alloy powder, Fe-Mn alloy powder, Fe-Ti alloy powder, Si powder, Al2O3 powder and Fe powder; S2. The weighed powders in step S1 are uniformly mixed in a planetary ball mill according to the proportion, and the mixed powders are melted in a vacuum induction furnace at a temperature set at 1450°C-1600°C for 1-2 hours; S3. The molten metal is quickly poured into a mold preheated to 300°C and cooled therein for 1 to 2 minutes; S4. The quenched alloy billet is heated to 600°C-800°C and maintained at this temperature for 4 hours, and then naturally cooled to room temperature; S5. The heat-treated billet is preheated in a heating furnace, and then the preheated billet is introduced into a drawing machine and stretched by applying a uniform tensile force; S6. Pickling the drawn Wiegand wire to remove the surface oxide layer, the pickling temperature is set at 50℃-60℃, the soaking time is 15 minutes, using 5wt%-10wt% sulfuric acid solution, and then sandblasting is performed.

7. The method for preparing low coercive force Wiegand wire according to claim 6, characterized in that: The particle size of the Al2O3 powder ranges from 100 nm to 500 nm.

8. The method for preparing low coercive force Wiegand wire according to claim 7, characterized in that: When applying a magnetic field during the pulling stage, a constant magnetic field of 100 mT to 500 mT is used, and the direction of the magnetic field is consistent with the pulling direction.

9. The method for preparing low coercive force Wiegand wire according to claim 8, characterized in that: The step S5 specifically includes the following steps: S51. heating the alloy billet to 800° C. to 1000° C., performing preliminary drawing at a drawing rate of 0.5 mm / s to 2 mm / s, drawing the alloy billet to 60% to 70% of the target diameter, and gradually cooling the first drawn alloy billet to room temperature after completing the first stage of drawing; S52. The alloy billet drawn for the first time after cooling is heated again, the temperature is set at 600° C. to 800° C., and a second-stage drawing is performed at a drawing rate of 2 mm / s to 5 mm / s, and the alloy billet drawn for the first time is drawn to 80% to 90% of the target diameter. After the second-stage drawing is completed, the alloy billet drawn for the second time is gradually cooled to room temperature; S53. The alloy billet drawn for the second time after cooling is heated again, the temperature is set at 600°C to 800°C, a drawing die is selected, and a final drawing is performed at a drawing rate of 2 mm / s to 5 mm / s, and the alloy billet drawn for the second time is drawn to a target diameter. After the final drawing is completed, the alloy billet drawn for the final time is gradually cooled to room temperature.

Images