Low-density current-based Wiegand filament preparation process

Abstract

The invention relates to the technical field of electronics, in particular to a Wiegand filament preparation process based on low-density current. The preparation process comprises the following steps: S1, uniformly mixing 14-16 parts of iron, 3-5 parts of cobalt and 1-5 parts of nickel alloy, putting 0.02-1 part of neodymium or dysprosium into a smelting furnace, uniformly mixing to obtain molten alloy liquid, refining the molten alloy liquid, pouring the molten alloy liquid into a mold, and cooling and solidifying to obtain an alloy sheet; s2, processing the alloy sheet into an alloy wire; s3, the alloy wire is subjected to annealing treatment under the nitrogen atmosphere; s4, when the temperature of the annealed wiegand filaments is reduced to 500 DEG C, applying low-density current to the annealed wiegand filaments, and repeating for 1-3 times; and S5, after the wiegand filaments are cooled, cutting the wiegand filaments into required lengths, and packaging the wiegand filaments. The invention provides a Wiegand filament preparation process based on low-density current, and aims to solve the problems that the stability is poor in a high-temperature environment, and current transmission and conductivity cannot meet the rapid signal transmission requirement in the related technology.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a Wiegand wire preparation process based on low-density current. Background Art

[0002] Wiegand wire is usually made of an alloy composed of metal elements such as cobalt, iron and vanadium. After special cold treatment and aging heat treatment, it forms a unique structure with a high coercive force shell and a soft magnetic center core. This structure enables the Wiegand wire to quickly flip the magnetic poles in an alternating external magnetic field, and generate a pulse current in the copper coil near the Wiegand wire, producing the Wiegand effect. The Wiegand effect is a nonlinear magnetic effect characterized by an extremely fast magnetic pole flipping speed (completed within a few microseconds), and the intensity and duration of the generated pulse current are not affected by the speed of change of the external magnetic field.

[0003] The Wiegand sensor with Wiegand wire as the main component can directly output 3-5V voltage pulses without the need for an external power supply and has a constant output characteristic. It has shown great application prospects in access control, metering, industrial automation, and automobiles.

[0004] Wiegand wire is commonly used in access control and sensors and has the characteristics of low power consumption, but it performs poorly in battery management systems and is not suitable for complex magnetic field environments and high temperature environments. It is unstable in high temperature environments and cannot maintain good magnetic properties. It cannot meet the requirements of efficient conductivity in current transmission and electronic communications, and has a narrow range of applications. Summary of the invention

[0005] The present application provides a Wiegand wire preparation process based on low-density current to solve the problems in the related art of poor stability in high-temperature environments, current transmission, and conductivity that cannot meet the requirements for rapid signal transmission.

[0006] In a first aspect, a low-density current-based Wiegand wire preparation process is provided, which comprises the following steps:

[0007] S1. Mix 14 to 16 parts of iron, 3 to 5 parts of cobalt, 1 to 5 parts of nickel alloy and 0.02 to 1 part of neodymium or dysprosium in a smelting furnace, mix them evenly to obtain a molten alloy liquid, refine the molten alloy liquid, pour it into a mold, and obtain an alloy sheet after cooling and solidification;

[0008] S2, processing the alloy sheet into alloy wire, wherein the diameter of the alloy wire is 0.3 mm;

[0009] S3, annealing the alloy wire in a nitrogen atmosphere at a temperature of 300 to 950° C. for 5 to 11 hours;

[0010] S4. When the temperature of the Wiegand wire after high temperature annealing drops to 500°C, a low-density current is applied to the Wiegand wire after annealing, and the process is repeated 1 to 3 times:

[0011] Provide density of 1~3A / m 2 A low-density current is applied to the Wiegand wire in the residual temperature of the heating, the current intensity is controlled between 5 and 35 mA, maintained for 10 to 90 seconds, and the Wiegand wire is obtained after cooling;

[0012] S5. After the Wiegand wire is cooled, it is cut to a desired length and packaged.

[0013] Preferably, the annealing process includes the following three stages:

[0014] The first stage: low temperature preheating, maintained at 300-500℃ for 1-2h;

[0015] The second stage: medium temperature annealing, maintained at 600-800℃ for 2-4h;

[0016] The third stage: high temperature annealing, maintained at 850-950°C for 2-5 hours.

[0017] Preferably, the S1 further includes:

[0018] Add 0.5 parts of nano iron oxide.

[0019] Preferably, in S5, after the Wiegand wire is cooled and before being cut, it further comprises:

[0020] The Wiegand yarn is immersed in polyurethane for 5 to 15 minutes, and then the immersed Wiegand yarn is placed in an oven and heated at 80 to 120° C. for 10 to 30 minutes for curing to obtain a cured Wiegand yarn;

[0021] The cured Wiegand wire is ground and polished to obtain the polyurethane-wrapped Wiegand wire.

[0022] The beneficial effects of the technical solution provided by this application include:

[0023] The embodiment of the present application provides a Wiegand wire preparation process based on low-density current. By applying low-density current to the manufacture of Wiegand wire, the rearrangement of the magnetic domains inside the Wiegand wire is induced, so that the coercive force of the outer shell is further enhanced, while the magnetic properties of the internal soft core remain unchanged, thereby enhancing the hysteresis effect and fast switching ability of the Wiegand wire under the action of an external magnetic field; under the action of current, impurity atoms, vacancies and other defects inside the Wiegand wire are driven by the electric field to migrate and recombine, thereby reducing the scattering effect of defects on carriers. At the same time, current treatment can promote the recrystallization or phase change process of the material, forming a purer and more uniform crystal structure, which is beneficial to the transmission of carriers and enhances its conductive properties;

[0024] Through high-temperature annealing treatment, the microstructure and magnetic properties of the Wiegand wire are optimized to ensure that the Wiegand wire reaches a higher performance state, so that its high-temperature resistance is improved and it can adapt to current transmission in a high-temperature environment to achieve the purpose of signal transmission. Therefore, it can solve the problems of poor stability in high-temperature environments, current transmission, and conductivity that cannot meet the requirements of fast signal transmission in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A flow chart of a low-density current-based Wiegand wire preparation process provided in this application;

[0027] Figure 2 IV curve diagrams of Examples 1 to 3 provided in this application;

[0028] Figure 3 IV curve diagrams of Example 4, Example 5 and Comparative Example 1 provided in this application;

[0029] Figure 4 IV curve diagrams of Comparative Examples 2 to 4 provided in this application;

[0030] Figure 5 Part of the temperature-resistance value curves of Examples 1 to 5 provided in this application;

[0031] Figure 6 This is a temperature-resistance curve diagram of Comparative Examples 1 to 4 provided in the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0033] The present application provides a low-density current-based Wiegand wire preparation process, which can solve the problems of poor stability in high-temperature environments, current transmission, and conductivity that cannot meet the requirements for fast signal transmission in related technologies. It includes the following steps:

[0034] S1. Evenly mix 14 to 16 parts of iron, 3 to 5 parts of cobalt, 1 to 5 parts of nickel alloy and 0.02 to 1 part of neodymium or dysprosium in a smelting furnace, mix evenly to obtain a molten alloy liquid, refine the molten alloy liquid, pour it into a mold, and obtain an alloy sheet after cooling and solidification.

[0035] Specifically, high-purity iron, cobalt and nickel alloys are used as basic materials to ensure that the produced Wiegand wire has good magnetic properties, and trace amounts of rare earth elements neodymium or special elements tungsten are added to increase the material's magnetic permeability and reduce its resistivity.

[0036] In some embodiments, it further includes 0.5 parts of nano iron oxide. Nano iron oxide has good chemical stability and corrosion resistance, and can effectively improve the surface quality and service life of Wiegand wire; at the same time, during the casting process of the alloy sheet, as the nano iron oxide solidifies, it will serve as the pinning center of the magnetic domain wall, effectively inhibiting the movement of the magnetic domain wall, thereby improving the magnetic stability and coercive force of the Wiegand wire.

[0037] S2, processing the alloy sheet into alloy wire with a diameter of 0.3 mm. Specifically, this step is to process the alloy sheet into a filament by hot rolling, cold rolling and other processes, which will not be described in detail here.

[0038] S3, annealing the alloy wire in a nitrogen atmosphere at a temperature of 300 to 950° C. for 5 to 11 hours;

[0039] In some embodiments, the annealing process includes the following three stages:

[0040] The first stage: low temperature preheating, maintained at 300-500℃ for 1-2h;

[0041] The second stage: medium temperature annealing, maintained at 600-800℃ for 2-4h;

[0042] The third stage: high temperature annealing, maintained at 850-950℃ for 2-5h;

[0043] S4. Apply low-density current to the annealed Wiegand wire and repeat 1 to 3 times:

[0044] Provide density of 1~3A / m 2 A low-density current is applied to the heated Wiegand wire, the current intensity is controlled between 5 and 35 mA, maintained for 10 to 90 seconds, and the Wiegand wire is obtained after cooling.

[0045] Low-density current treatment rearranges the magnetic domains inside the Wiegand wire, further enhancing the coercive force of the outer shell, while the magnetic properties of the soft core inside remain unchanged. This treatment enhances the hysteresis effect and fast switching ability of the Wiegand wire under the action of an external magnetic field; under the action of an external magnetic field, the Wiegand wire can more effectively isolate the internal soft core until a higher magnetic threshold is reached before the switching of the magnetization polarity occurs. That is, the Wiegand wire has a stronger anti-interference ability to the outside world. When the polarity of the external excitation magnetic field jumps, the sensor can output a pulse signal, and the stability is enhanced.

[0046] Furthermore, under the action of electric current, impurity atoms, vacancies and other defects inside the Wiegand wire are driven by the electric field to migrate and recombine, thereby reducing the scattering effect of defects on carriers. At the same time, current treatment can promote the recrystallization or phase change process of the material, forming a purer and more uniform crystal structure, which is conducive to the transmission of carriers. In addition, current treatment can also change the band structure or carrier concentration distribution inside the Wiegand wire, thereby improving its conductive properties.

[0047] These characteristics improve the stability and reliability of Wiegand wire in complex magnetic field environments, and due to the enhanced hysteresis characteristics and rapid magnetic pole switching, the coil with Wiegand wire processed by low-density current as the core can output more stable voltage pulses. This stable output voltage is essential for driving microprocessors and achieving high-precision measurements, and has high application value in current transmission and electronic communications.

[0048] When the temperature of the Wiegand wire after high-temperature annealing drops to 500°C, a low-density current is applied to the Wiegand wire. On the one hand, the heat resistance of the Wiegand wire is enhanced through multi-stage annealing, in which the low-temperature preheating stage is used to remove the residual stress and microscopic defects inside the Wiegand wire, laying the foundation for the subsequent annealing process, and the medium-temperature annealing stage further refines its grain structure and improves the uniformity and stability of the Wiegand wire. The high-temperature annealing stage is the final optimization of the performance of the Wiegand wire, that is, optimizing the microstructure and magnetic properties of the Wiegand wire to ensure that the Wiegand wire reaches a higher performance state.

[0049] S5. After the Wiegand wire is cooled, it is cut to a desired length and packaged.

[0050] In some embodiments, after the Wiegand wire is cooled and before being cut, it further comprises the following steps:

[0051] The Wiegand yarn is immersed in polyurethane for 5 to 15 minutes, and then the immersed Wiegand yarn is placed in an oven and heated at 80 to 120° C. for 10 to 30 minutes for curing to obtain a cured Wiegand yarn;

[0052] The cured Wiegand wire is ground and polished to obtain the polyurethane-wrapped Wiegand wire.

[0053] Polyurethane has good wear resistance, corrosion resistance and elasticity, and can effectively protect Wiegand wire from erosion by the external environment. Through heating and curing treatment, cross-linking reaction occurs between polyurethane molecular chains to form a dense network structure, thereby enhancing the bonding force between the coating and the Wiegand wire; a tough and smooth coating is formed on the surface of the Wiegand wire wrapped by polyurethane, which can improve the wear resistance, corrosion resistance and anti-aging performance of the Wiegand wire and extend its service life.

[0054] Example 1

[0055] S1. 14 g of iron, 5 g of cobalt, 1 g of nickel alloy and 0.02 g of neodymium are placed in a smelting furnace and mixed evenly to obtain a molten alloy liquid. The molten alloy liquid is refined and poured into a mold. After cooling and solidification, an alloy sheet is obtained;

[0056] S2, processing the alloy sheet into an alloy wire with a diameter of 0.3 mm;

[0057] S3, annealing the alloy wire in a nitrogen atmosphere:

[0058] The first stage: low temperature preheating, maintained at 300℃ for 2h;

[0059] The second stage: medium temperature annealing, maintained at 600℃ for 4h;

[0060] The third stage: high temperature annealing, maintained at 850℃ for 5h;

[0061] S4. When the temperature of the Wiegand wire after high temperature annealing drops to 500°C, a low-density current is applied to the Wiegand wire and repeated 3 times:

[0062] Provides a density of 1A / m 2 A low-density current of 35 mA is applied to the Wiegand wire in the residual temperature of heating, and the current intensity is maintained for 90 seconds. After cooling, the Wiegand wire is obtained;

[0063] S5. After the Wiegand wire is cooled, it is cut to a desired length and packaged.

[0064] Example 2

[0065] S1. 16 g of iron, 3 g of cobalt, 5 g of nickel alloy and 1 g of neodymium are placed in a smelting furnace, mixed evenly to obtain a molten alloy liquid, the molten alloy liquid is refined, poured into a mold, and cooled and solidified to obtain an alloy sheet;

[0066] S2, processing the alloy sheet into an alloy wire with a diameter of 0.3 mm;

[0067] S3, annealing the alloy wire in a nitrogen atmosphere:

[0068] The first stage: low temperature preheating, maintained at 500℃ for 1h;

[0069] The second stage: medium temperature annealing, maintained at 800℃ for 1h;

[0070] The third stage: high temperature annealing, maintained at 900℃ for 2h;

[0071] S4. When the temperature of the Wiegand wire after high temperature annealing drops to 500°C, a low-density current is applied to the Wiegand wire:

[0072] Provides a density of 3A / m 2 A low-density current of 5 mA is applied to the Wiegand wire in the residual temperature of heating, and the current intensity is maintained for 10 seconds. After cooling, the Wiegand wire is obtained;

[0073] S5. After the Wiegand wire is cooled, it is cut to a desired length and packaged.

[0074] Example 3

[0075] S1. Place 15g of iron, 4g of cobalt, 3g of nickel alloy and 0.4g of neodymium in a smelting furnace. When the solid is molten, add 0.5g of nano iron oxide and mix well to obtain a molten alloy liquid. Refine the molten alloy liquid, pour it into a mold, and obtain an alloy sheet after cooling and solidification.

[0076] S2, processing the alloy sheet into an alloy wire with a diameter of 0.3 mm;

[0077] S3, annealing the alloy wire in a nitrogen atmosphere:

[0078] The first stage: low temperature preheating, maintained at 400℃ for 1.5h;

[0079] The second stage: medium temperature annealing, maintained at 700℃ for 3h;

[0080] The third stage: high temperature annealing, maintained at 850℃ for 3h;

[0081] S4. When the temperature of the Wiegand wire after high temperature annealing drops to 500°C, a low-density current is applied to the Wiegand wire and repeated twice:

[0082] Provides a density of 2A / m 2 A low-density current of 15 mA is applied to the Wiegand wire in the residual temperature of the heating, and the current is maintained for 40 seconds. After cooling, the Wiegand wire is obtained;

[0083] S5, after the Wiegand wire is cooled, immersing the Wiegand wire in polyurethane, keeping it for 10 minutes, placing the immersed Wiegand wire in an oven, heating it at 90° C. for 20 minutes, and curing it to obtain a cured Wiegand wire;

[0084] The cured Wiegand wire is ground and polished to obtain a polyurethane-wrapped Wiegand wire, which is then cut into a desired length and packaged.

[0085] Example 4

[0086] S1. Place 15g of iron, 4g of cobalt, 3g of nickel alloy and 0.6g of dysprosium in a smelting furnace. When the solid is molten, add 0.5g of nano iron oxide and mix well to obtain a molten alloy liquid. Refine the molten alloy liquid, pour it into a mold, and obtain an alloy sheet after cooling and solidification.

[0087] S2, processing the alloy sheet into an alloy wire with a diameter of 0.3 mm;

[0088] S3, annealing the alloy wire in a nitrogen atmosphere:

[0089] The first stage: low temperature preheating, maintained at 400℃ for 1.5h;

[0090] The second stage: medium temperature annealing, maintained at 700℃ for 3h;

[0091] The third stage: high temperature annealing, maintained at 850℃ for 3h;

[0092] S4. When the temperature of the Wiegand wire after high temperature annealing drops to 500°C, a low-density current is applied to the Wiegand wire and repeated twice:

[0093] Provides a density of 1A / m 2 A low-density current of 20 mA is applied to the Wiegand wire in the residual temperature of the heating, and the current intensity is maintained for 50 seconds. After cooling, the Wiegand wire is obtained;

[0094] S5, after the Wiegand wire is cooled, immersing the Wiegand wire in polyurethane, keeping it for 15 minutes, placing the immersed Wiegand wire in an oven, heating it at 120° C. for 10 minutes, and curing it to obtain a cured Wiegand wire;

[0095] The cured Wiegand wire is ground and polished to obtain a polyurethane-wrapped Wiegand wire, which is then cut into a desired length and packaged.

[0096] Example 5

[0097] S1. Place 15g of iron, 4g of cobalt, 4g of nickel alloy and 0.4g of dysprosium in a smelting furnace. When the solid is molten, add 0.5g of nano iron oxide and mix well to obtain a molten alloy liquid. Refine the molten alloy liquid, pour it into a mold, and obtain an alloy sheet after cooling and solidification.

[0098] S2, processing the alloy sheet into an alloy wire with a diameter of 0.3 mm;

[0099] S3, annealing the alloy wire in a nitrogen atmosphere:

[0100] The first stage: low temperature preheating, maintained at 400℃ for 1.5h;

[0101] The second stage: medium temperature annealing, maintained at 700℃ for 3h;

[0102] The third stage: high temperature annealing, maintained at 850℃ for 3h;

[0103] S4. When the temperature of the Wiegand wire after high temperature annealing drops to 500°C, a low-density current is applied to the Wiegand wire and repeated twice:

[0104] Provides a density of 1.5A / m 2 A low-density current of 15 mA is applied to the Wiegand wire in the residual temperature of the heating, and the current is maintained for 40 seconds. After cooling, the Wiegand wire is obtained;

[0105] S5, after the Wiegand wire is cooled, immersing the Wiegand wire in polyurethane, keeping for 5 minutes, placing the immersed Wiegand wire in an oven, heating at 80° C. for 30 minutes, and curing to obtain a cured Wiegand wire;

[0106] The cured Wiegand wire is ground and polished to obtain a polyurethane-wrapped Wiegand wire, which is then cut into a desired length and packaged.

[0107] Comparative Example 1

[0108] Except that step S4 does not apply low-density current to the heat-treated Wiegand wire, the remaining steps are the same as those in Example 3.

[0109] Comparative Example 2

[0110] S1. Place 15g of iron, 4g of cobalt, 3g of nickel alloy and 0.4g of neodymium in a smelting furnace. When the solid is molten, add 0.5g of nano iron oxide and mix well to obtain a molten alloy liquid. Refine the molten alloy liquid, pour it into a mold, and obtain an alloy sheet after cooling and solidification.

[0111] S2, processing the alloy sheet into an alloy wire with a diameter of 0.3 mm;

[0112] S3, annealing the alloy wire in a nitrogen atmosphere at a temperature of 750° C. for 8 hours;

[0113] S4. When the temperature of the Wiegand wire after annealing is reduced to 500°C, a low-density current is applied to the Wiegand wire and repeated twice:

[0114] Provides a density of 2A / m 2 A low-density current of 15 mA is applied to the Wiegand wire in the residual temperature of the heating, and the current is maintained for 40 seconds. After cooling, the Wiegand wire is obtained;

[0115] S4, after the Wiegand wire is cooled, immersing the Wiegand wire in polyurethane, keeping it for 10 minutes, placing the immersed Wiegand wire in an oven, heating it at 90° C. for 20 minutes, and curing it to obtain a cured Wiegand wire;

[0116] The cured Wiegand wire is ground and polished to obtain a polyurethane-wrapped Wiegand wire, which is then cut into a desired length and packaged.

[0117] Comparative Example 3

[0118] S1. Place 15g of iron, 4g of cobalt, 3g of nickel alloy and 0.4g of neodymium in a smelting furnace. When the solid is molten, add 0.5g of nano iron oxide and mix well to obtain a molten alloy liquid. Refine the molten alloy liquid, pour it into a mold, and obtain an alloy sheet after cooling and solidification.

[0119] S2, processing the alloy sheet into an alloy wire with a diameter of 0.3 mm;

[0120] S3, annealing the alloy wire in a nitrogen atmosphere at a temperature of 750° C. for 8 hours;

[0121] S4, after the Wiegand wire is cooled, immersing the Wiegand wire in polyurethane, keeping it for 10 minutes, placing the immersed Wiegand wire in an oven, heating it at 90° C. for 20 minutes, and curing it to obtain a cured Wiegand wire;

[0122] The cured Wiegand wire is ground and polished to obtain a polyurethane-wrapped Wiegand wire, which is then cut into a desired length and packaged.

[0123] Comparative Example 4

[0124] Except that neodymium is not added in step S1, the remaining steps are the same as those in Example 3.

[0125] The Wiegand wires manufactured in Examples 1 to 5 and Comparative Examples 1 to 4 were tested.

[0126] Current-voltage (IV) characteristic test: Connect both ends of the manufactured Wiegand wire to the test fixture, set the current from zero, record the voltage value corresponding to each current point at 0.5A, 1A, 1.5A, 2A, and 2.5A, and draw the IV characteristic curve.

[0127] Specifically, the higher the linearity of the IV curve, the more stable the resistance value and the better the conductivity.

[0128] from Figure 2 to Figure 4 It can be seen that the IV curves of Examples 3 to 5 are highly linear, the resistance values ​​are stable, and there is no obvious fluctuation; the IV curves of Examples 1 to 2 and Comparative Example 1 are basically linear, but there may be slight fluctuations or nonlinear regions, and the resistance value changes are within an acceptable range; the IV curves of Comparative Examples 2 to 4 are obviously nonlinear, and the resistance values ​​change greatly, but are still within the workable range.

[0129] Temperature cycle test: Use a high and low temperature test chamber, place the Wiegand wire sample in the test chamber, connect the test circuit (the circuit voltage is set to 2V), set the temperature cycle range of the test chamber to -25~85℃, and the test temperature points are -25℃, 40℃ and 85℃ respectively. Set the temperature cycle cycle (stay at each temperature point for 20 minutes, and then quickly switch to the next temperature point), and set the number of cycles to 150 times; after the temperature point stabilizes (the temperature in the test chamber fluctuates within ±1℃), measure and record the resistance value of the Wiegand wire.

[0130] The applicant intercepted the temperature-resistance curves of two cycles at the end of the cycle (140 to 142 times), see Figure 5-6 shown.

[0131] It can be seen that the temperature-resistance curves of Examples 3 to 5 are gentle, the resistance value changes little with temperature, the performance is stable, there is no degradation phenomenon, and the thermal stability is relatively excellent; the temperature-resistance curves of Examples 1 to 2 and Comparative Examples 1 and 4 are relatively gentle, the resistance value fluctuates with temperature, but is still within an acceptable range, the performance degradation is not obvious, and the thermal stability is good; the resistance value of Comparative Examples 2 and 3 changes greatly with temperature, the performance degradation is obvious, and the thermal stability is poor.

[0132] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A process for preparing Wiegand wire based on low-density current, characterized in that: It includes the following steps: S1. Mix 14 to 16 parts of iron, 3 to 5 parts of cobalt, 1 to 5 parts of nickel alloy and 0.02 to 1 part of neodymium or dysprosium in a smelting furnace, mix them evenly to obtain a molten alloy liquid, refine the molten alloy liquid, pour it into a mold, and obtain an alloy sheet after cooling and solidification; S2, processing the alloy sheet into alloy wire, wherein the diameter of the alloy wire is 0.3 mm; S3, annealing the alloy wire in a nitrogen atmosphere at a temperature of 300 to 950° C. for 5 to 11 hours; S4. When the temperature of the annealed Wiegand wire itself drops to 500°C, a low-density current is applied to the annealed Wiegand wire, and the process is repeated 1 to 3 times: Provide density of 1~3A / m 2 A low-density current is applied to the Wiegand wire in the residual temperature of the heating, the current intensity is controlled between 5 and 35 mA, maintained for 10 to 90 seconds, and the Wiegand wire is obtained after cooling; S5. After the Wiegand wire is cooled, it is cut to a desired length and packaged.

2. The low-density current-based Wiegand wire preparation process according to claim 1, characterized in that: The annealing process includes the following three stages: The first stage: low temperature preheating, maintained at 300-500℃ for 1-2h; The second stage: medium temperature annealing, maintained at 600-800℃ for 2-4h; The third stage: high temperature annealing, maintained at 850-950°C for 2-5 hours.

3. The low-density current-based Wiegand wire preparation process according to claim 1, characterized in that: The S1 further comprises: Add 0.5 parts of nano iron oxide.

4. The low-density current-based Wiegand wire preparation process according to claim 1, characterized in that: In the S5, after the Wiegand wire is cooled and before cutting, it also includes: The Wiegand yarn is immersed in polyurethane for 5 to 15 minutes, and then the immersed Wiegand yarn is placed in an oven and heated at 80 to 120° C. for 10 to 30 minutes for curing to obtain a cured Wiegand yarn; The cured Wiegand wire is ground and polished to obtain the polyurethane-wrapped Wiegand wire.

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