Wiegand filament as well as preparation method and application thereof

Abstract

The invention discloses a wiegand filament and a preparation method and application thereof.The wiegand filament comprises at least one first magnetic material layer and at least one second magnetic material layer, and the first magnetic material layers and the second magnetic material layers are alternately stacked in the direction perpendicular to the length direction of the wiegand filament; the coercive force of the first magnetic material layer is greater than the coercive force of the second magnetic material layer. The wiegand filament comprises the first magnetic material layer and the second magnetic material layer which are alternately stacked, and the coercive force between the first magnetic material layer and the second magnetic material layer has a clear boundary, so that the electric pulse intensity generated by the wiegand filament is remarkably improved. In addition, the alternate stacking structure of the wiegand filaments can adopt a stacking and bonding preparation method, and the production efficiency of the wiegand filaments can be improved through the preparation method.

Description

Technical Field

[0001] The present invention belongs to the technical field of Weigand, and particularly relates to a Weigand wire and its preparation method and application. Background Art

[0002] The application of Weigand sensors is extremely extensive. Since the Weigand sensors were invented in the 1970s, they have been widely used in fields such as access control and security, water meters, gas meters, oil meters, multi-turn encoders, etc. Due to the characteristic that the Weigand effect is not related to time, Weigand sensors can be used as counting sensors, micro-energy harvesting elements, or the two functions can be combined to form a self-powered sensor. And the most critical component in the Weigand sensor is the Weigand wire.

[0003] However, the cross-section of the existing Weigand wire is generally cylindrical, with a hard magnetic shell on the outer layer and a soft magnetic core on the inner layer. The coercivity of the existing Weigand wire gradually changes from the outside to the inside, and there is no clear demarcation line between the coercivity of the outer hard magnetic shell and the inner soft magnetic core, resulting in weak electrical pulses generated by the existing Weigand wire.

[0004] In addition, the current manufacturing process of Weigand wire is complex. In the manufacturing process, the Villari alloy wire needs to undergo multi-cycle heat treatment and / or stress application before the required Weigand wire can be obtained. The complex production process leads to extremely low production efficiency of Weigand wire, and any parameter error in any link may result in unqualified products in this batch. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to some extent. For this purpose, the object of the present invention is to provide a Weigand wire and its preparation method and application. The Weigand wire of the present invention includes a first magnetic material layer and a second magnetic material layer alternately stacked, and there is a clear demarcation line between the coercivities of the first magnetic material layer and the second magnetic material layer, thus significantly increasing the intensity of the electrical pulses generated by the Weigand wire. In addition, the alternately stacked structure of the Weigand wire of the present invention can adopt a preparation method of stacking + bonding, which can improve the production efficiency of the Weigand wire.

[0006] In one aspect of the present invention, a Weigand wire is provided. According to an embodiment of the present invention, the Weigand wire includes:

[0007] At least one layer of a first magnetic material layer and at least one layer of a second magnetic material layer, the first magnetic material layer and the second magnetic material layer are alternately stacked in a direction perpendicular to the length direction of the Weigand wire, and the coercivity of the first magnetic material layer is greater than that of the second magnetic material layer.

[0008] The Weigand wire according to an embodiment of the present invention includes a first magnetic material layer and a second magnetic material layer that are alternately stacked, and there is a clear demarcation line in the coercivity between the first magnetic material layer and the second magnetic material layer, thereby significantly increasing the intensity of the electrical pulses generated by the Weigand wire. In addition, the alternating stacked structure of the Weigand wire of the present invention can adopt a preparation method of stacking + bonding, and this preparation method can improve the production efficiency of the Weigand wire.

[0009] In addition, the Weigand wire according to the above embodiment of the present invention may further have the following additional technical features:

[0010] In some embodiments of the present invention, the difference between the coercivity of the first magnetic material layer and the coercivity of the second magnetic material layer is greater than 10 Oe.

[0011] In some embodiments of the present invention, the difference between the coercivity of the first magnetic material layer and the coercivity of the second magnetic material layer is 20 Oe - 60 Oe.

[0012] In some embodiments of the present invention, the Weigand wire includes the first magnetic material layer and the second magnetic material layer that are sequentially stacked, and the first magnetic material layer and the second magnetic material layer form a single stack; or, it includes the first magnetic material layer, the second magnetic material layer, and the first magnetic material layer that are sequentially stacked; or, it includes the second magnetic material layer, the first magnetic material layer, and the second magnetic material layer that are sequentially stacked; or, it includes multiple layers of the first magnetic material layer and multiple layers of the second magnetic material layer, and the first magnetic material layer and the second magnetic material layer are alternately stacked.

[0013] In some embodiments of the present invention, the coercivity of the first magnetic material layer is 20 Oe - 100 Oe; and / or, the coercivity of the second magnetic material layer is 10 Oe - 90 Oe.

[0014] In some embodiments of the present invention, the first magnetic material layer includes at least one of Fe-Co-V alloy, Fe-Ni alloy, Fe-Si-B alloy, Fe-Co-Ni-Si-B alloy, Co-Fe-Mn-Si-B alloy, Ni-Zr alloy; and / or, the second magnetic material layer includes at least one of Fe-Co-V alloy, Fe-Ni alloy, Fe-Si-B alloy, Fe-Co-Ni-Si-B alloy, Co-Fe-Mn-Si-B alloy, Ni-Zr alloy.

[0015] In some embodiments of the present invention, the ratio of the thickness of the first magnetic material layer to the thickness of the second magnetic material layer is (1:10) - (10:1).

[0016] In some embodiments of the present invention, the total thickness of the stacked Weigand wires is greater than 20 μm and less than 1 mm.

[0017] In some embodiments of the present invention, an adhesive layer is provided between the adjacent first magnetic material layer and the second magnetic material layer, and the adhesive layer is used to bond the first magnetic material layer and the second magnetic material layer.

[0018] In some embodiments of the present invention, the thickness of the adhesive layer is less than the thickness of the first magnetic material layer, and the thickness of the adhesive layer is less than the thickness of the second magnetic material layer.

[0019] In some embodiments of the present invention, the thickness of the adhesive layer is less than 200 μm.

[0020] In some embodiments of the present invention, the adhesive layer includes at least one of a thermosetting adhesive, a photocuring adhesive, and a natural curing adhesive.

[0021] In some embodiments of the present invention, the thermosetting adhesive includes at least one of an epoxy resin adhesive, a phenolic resin adhesive, an imino resin adhesive, and a polyurethane resin adhesive.

[0022] In still another aspect of the present invention, the present invention provides a method for preparing the above-mentioned Weigand wire. According to an embodiment of the present invention, the method includes:

[0023] Stack at least one layer of the first magnetic material layer and at least one layer of the second magnetic material layer, and the first magnetic material layer and the second magnetic material layer are alternately stacked, and the coercivity of the first magnetic material layer is greater than the coercivity of the second magnetic material layer;

[0024] Bond the adjacent first magnetic material layer and the second magnetic material layer so that the adjacent first magnetic material layer and the second magnetic material layer are bonded together to obtain a stacked structure;

[0025] Cut the stacked structure according to a preset size to obtain a Weigand wire.

[0026] According to the method for preparing the above-mentioned Weigand wire according to the embodiment of the present invention, the first magnetic material layer and the second magnetic material layer are directly alternately stacked, avoiding multi-cycle heat treatment and stress application to the alloy wire in the prior art, thereby improving the production efficiency of the Weigand wire and solving the problem of low production efficiency of the Weigand wire. In addition, the problem that if there is a break in one place on a wire to be processed in the existing method, the entire Weigand wire may not be usable is avoided, thereby improving the production efficiency of the Weigand wire. At the same time, there is a clear demarcation line in the coercivity between the first magnetic material layer and the second magnetic material layer of the Weigand wire prepared by the above method, thereby significantly increasing the intensity of the electrical pulse generated by the Weigand wire.

[0027] In addition, the method according to the above embodiments of the present invention may further have the following additional technical features:

[0028] In some embodiments of the present invention, the method includes:

[0029] Stack at least one layer of the first magnetic material layer and at least one layer of the second magnetic material layer on the first substrate, and the first magnetic material layer and the second magnetic material layer are alternately stacked, and an adhesive is coated on at least part of the surface of the first magnetic material layer that fits the second magnetic material layer and / or at least part of the surface of the second magnetic material layer that fits the first magnetic material layer;

[0030] Place a second substrate on the uppermost magnetic material layer;

[0031] Cure the adhesive to bond the adjacent first magnetic material layer and the second magnetic material layer;

[0032] After the first magnetic material layer and the second magnetic material layer are bonded, remove the first substrate and the second substrate to obtain a stacked structure;

[0033] Cut the stacked structure according to a preset size to obtain the Weigand wire.

[0034] In some embodiments of the present invention, before curing the adhesive, the method further includes: applying pressure between the first substrate and the second substrate.

[0035] In some embodiments of the present invention, the adhesive includes at least one of a thermosetting adhesive, a photocurable adhesive, and a naturally curable adhesive.

[0036] In some embodiments of the present invention, the first substrate includes a first plexiglass layer, a first silicone layer, and a first polytetrafluoroethylene film layer stacked in sequence, and the first polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer or the second magnetic material layer.

[0037] In some embodiments of the present invention, the second substrate includes a second plexiglass layer, a second silicone layer, and a second polytetrafluoroethylene film layer stacked in sequence, and the second polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer or the second magnetic material layer.

[0038] In a third aspect of the present invention, the present invention provides a Weigand sensor. According to an embodiment of the present invention, the Weigand sensor has the Weigand wire of the above embodiment or the Weigand wire prepared by the method of the above embodiment, and the coercive forces of all the first magnetic material layers are equal, and the coercive forces of all the second magnetic material layers are equal. Thus, by increasing the intensity of the electrical pulses generated by the Weigand wire, the accuracy of the Weigand sensor is improved.

[0039] In a fourth aspect of the present invention, the present invention provides an energy harvester. According to an embodiment of the present invention, the energy harvester has the Weigand wire of the above embodiment or the Weigand wire prepared by the method of the above embodiment. Thus, by increasing the intensity of the electrical pulses generated by the Weigand wire, the efficiency of the energy harvester for collecting electrical energy is improved.

[0040] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0042] Figure 1 is a schematic structural diagram of a Weigand wire according to some embodiments of the present invention;

[0043] Figure 2 is a schematic structural diagram of a Weigand wire according to some other embodiments of the present invention;

[0044] Figure 3 is a schematic structural diagram of a Weigand wire according to some further embodiments of the present invention;

[0045] Figure 4 is a schematic structural diagram of a Weigand wire according to some further embodiments of the present invention;

[0046] Figure 5 is a schematic structural diagram of a Weigand wire in the related art;

[0047] Figure 6 is a cross-sectional view of a Weigand wire in the related art;

[0048] Figure 7 is a schematic flow diagram of a method for preparing a Weigand wire according to some embodiments of the present invention;

[0049] Figure 8 is a schematic flow diagram of a method for preparing a Weigand wire according to some other embodiments of the present invention;

[0050] Figure 9 is a schematic stacking diagram of a method for preparing a Weigand wire according to an embodiment of the present invention.

[0051] Reference numerals:

[0052] 100 - Weigand wire, 10 - first magnetic material layer, 20 - second magnetic material layer, 30 - adhesive layer, 31 - adhesive, 200 - first substrate, 300 - second substrate. Detailed implementation manners

[0053] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0054] Explanation of key terms:

[0055] Weigand effect: In an alternating magnetic field, when the magnetic field of a certain polarity (such as the N pole) parallel to the Weigand wire reaches the trigger magnetic induction intensity, the magnetic domains in the sensitive wire are excited and will move, and the magnetization direction instantaneously turns to the same direction. At the same time, the magnetic field in the space around the sensitive wire also changes instantaneously, thereby inducing an electrical pulse in the induction coil. Thereafter, if the magnetic field weakens, the magnetization direction of the sensitive wire will remain stable and unchanged, and no pulse is output from the induction coil; but when the magnetic field of the opposite polarity (S pole) increases to the trigger magnetic induction intensity, the magnetization direction of the sensitive wire instantaneously flips again, and an electrical pulse with the opposite direction is induced in the induction coil.

[0056] Weigand wire: A filamentous magnetic material that can generate Weigand pulses under the action of an alternating magnetic field.

[0057] Hard magnetic material: A ferromagnetic material with a relatively large magnetic coercivity is a hard magnetic material.

[0058] Soft magnetic material: A ferromagnetic material with a relatively small magnetic coercivity is a soft magnetic material. Hard magnetic materials and soft magnetic materials are only relative, and there is actually no clear boundary between hard magnetic materials and soft magnetic materials.

[0059] Weigand pulse: Under the action of an alternating magnetic field, a Weigand wire can generate a magnetic signal with a very short pulse. This magnetic signal is usually captured by a coil wound around the Weigand wire and converted into an electrical signal.

[0060] Weak energy harvesting: The method of collecting weak-field energy in the environment and converting it into an electrical signal, and then storing the electrical signal in a capacitor or battery is called weak-field energy harvesting. In the present invention, it refers to weak magnetic field energy. The alternating magnetic energy in the environment is captured by using a Weigand wire and a coil and then converted into electrical energy, and then stored in the capacitor or battery of the circuit system.

[0061] In one aspect of the present invention, the present invention provides a Weigand wire. According to an embodiment of the present invention, with reference to the attached Figures 1-4 , the Weigand wire 100 includes: at least one layer of a first magnetic material layer 10 and at least one layer of a second magnetic material layer 20. The first magnetic material layer 10 and the second magnetic material layer 20 are alternately stacked in a direction perpendicular to the length of the Weigand wire, and the coercivity of the first magnetic material layer 10 is greater than that of the second magnetic material layer 20. Thus, the Weigand wire of the present invention includes the first magnetic material layer 10 and the second magnetic material layer 20 that are alternately stacked, and there is a clear demarcation line between the coercivities of the first magnetic material layer 10 and the second magnetic material layer 20, thereby significantly increasing the intensity of the electrical pulse generated by the Weigand wire. In addition, the alternating stacked structure of the Weigand wire of the present invention can adopt a preparation method of stacking + bonding, and this preparation method can improve the production efficiency of the Weigand wire.

[0062] The principle by which the Weigand wire proposed by the present invention can achieve the above beneficial effects will be described in detail below:

[0063] With reference to the attached Figure 5 and 6 , the Weigand wire 100 in the related art is generally slender and cylindrical, and its cross-section is approximately circular. The outer layer of the circle is a hard magnetic shell, and the inner layer is a soft magnetic core. The coercivity of the Weigand wire 100 in the related art gradually changes from the outside to the inside, that is, there is no clear demarcation line between the coercivity of the outer hard magnetic shell and the coercivity of the inner soft magnetic core, resulting in a relatively weak electrical pulse generated by the existing Weigand wire.

[0064] In order to solve the above technical problems, the inventor of the present invention provides the alternately stacked first magnetic material layer 10 and second magnetic material layer 20, and defines that the coercivity of the first magnetic material layer 10 is greater than that of the second magnetic material layer 20. Relatively speaking, the first magnetic material layer 10 is a hard magnetic material layer, and the second magnetic material layer 20 is a soft magnetic material layer. Therefore, there is a clear demarcation line between the coercivities of the first magnetic material layer 10 and the second magnetic material layer 20, thereby significantly increasing the intensity of the electrical pulse generated by the Weigand wire.

[0065] The process of the Weigand wire 100 of the present invention generating electrical pulses is as follows: 1) The initial magnetic field is zero. As the externally applied magnetic field increases, both the first magnetic material layer 10 and the second magnetic material layer 20 are magnetized in the positive direction. 2) Apply a magnetic field in the reverse direction. The first magnetic material layer 10 is first magnetized in the reverse direction. When the reverse magnetic field increases to the trigger magnetic induction intensity (i.e., when the second magnetic material layer 20 is also magnetized in the reverse direction), the magnetic field in the space around the Weigand wire also changes instantaneously, thereby inducing an electrical pulse in the induction coil. 3) Similarly, apply a magnetic field in the positive direction. The first magnetic material layer 10 is first magnetized in the positive direction. When the positive magnetic field increases to the trigger magnetic induction intensity (i.e., when the second magnetic material layer 20 is also magnetized in the positive direction), the magnetization direction of the Weigand wire instantaneously flips again, and an electrical pulse in the opposite direction is induced in the induction coil. It should be noted that the greater the difference between the coercivity of the first magnetic material layer 10 and the coercivity of the second magnetic material layer 20, the stronger the intensity of the electrical pulses generated by the Weigand wire.

[0066] In addition, the alternating laminated structure of the Weigand wire of the present invention can adopt a preparation method of lamination + bonding, which can improve the production efficiency of the Weigand wire.

[0067] According to some specific embodiments of the present invention, the difference between the coercivity of the first magnetic material layer 10 and the coercivity of the second magnetic material layer 20 can be greater than 10 Oe. Thus, it further ensures that there is a clear demarcation line between the coercivities of the first magnetic material layer 10 and the second magnetic material layer 20, thereby further significantly increasing the intensity of the electrical pulses generated by the Weigand wire.

[0068] As some preferred solutions, the difference between the coercivity of the first magnetic material layer 10 and the coercivity of the second magnetic material layer 20 can be 20 Oe - 60 Oe (for example, it can be 20 Oe, 30 Oe, 40 Oe, 50 Oe, 60 Oe, etc.). Thus, it further ensures that there is a clear demarcation line between the coercivities of the first magnetic material layer 10 and the second magnetic material layer 20, thereby further significantly increasing the intensity of the electrical pulses generated by the Weigand wire.

[0069] It should be noted that the coercivity at each part of the first magnetic material layer 10 can be equal or unequal. When the coercivity at each part of the first magnetic material layer 10 is unequal, the coercivity of the first magnetic material layer 10 refers to the average coercivity of the first magnetic material layer 10. Similarly, the coercivity at each part of the second magnetic material layer 20 can be equal or unequal. When the coercivity at each part of the second magnetic material layer 20 is unequal, the coercivity of the second magnetic material layer 20 refers to the average coercivity of the second magnetic material layer 20.

[0070] In the embodiments of the present invention, the specific laminated structure of the Weigand wire is not particularly limited. According to some specific embodiments of the present invention, refer to the attachedFigure 1 , the Weigand wire 100 may include a first magnetic material layer 10 and a second magnetic material layer 20 which are stacked in sequence. The first magnetic material layer 10 and the second magnetic material layer 20 form a single stack. There is a clear demarcation line in the coercivity between the first magnetic material layer 10 and the second magnetic material layer 20 of this structure Weigand wire, thus significantly improving the intensity of the electrical pulse generated by the Weigand wire.

[0071] It should be noted that in the appendix Figures 1-4 , X represents the length direction of the Weigand wire 100, and X represents the thickness direction of the Weigand wire 100.

[0072] According to some further specific embodiments of the present invention, referring to the appendix Figure 2 , the Weigand wire 100 may include a first magnetic material layer 10, a second magnetic material layer 20, and a first magnetic material layer 10 which are stacked in sequence, that is, a sandwich stack structure of the first magnetic material layer 10 + the second magnetic material layer 20 + the first magnetic material layer 10 is formed. There is a clear demarcation line in the coercivity between the second magnetic material layer 20 and the two first magnetic material layers 10 of this structure Weigand wire, thus significantly improving the intensity of the electrical pulse generated by the Weigand wire. Or, the Weigand wire may include a second magnetic material layer 20, a first magnetic material layer 10, and a second magnetic material layer 20 which are stacked in sequence, that is, a sandwich stack structure of the second magnetic material layer 20 + the first magnetic material layer 10 + the second magnetic material layer 20 is formed. There is a clear demarcation line in the coercivity between the first magnetic material layer 10 and the two second magnetic material layers 20 of this structure Weigand wire, thus significantly improving the intensity of the electrical pulse generated by the Weigand wire.

[0073] According to some other specific embodiments of the present invention, referring to the appendix Figure 3 , the Weigand wire 100 may include multiple first magnetic material layers 10 and multiple second magnetic material layers 20. The first magnetic material layers 10 and the second magnetic material layers 20 are alternately stacked to form a stack structure of at least four layers. There is a clear demarcation line in the coercivity between each adjacent first magnetic material layer 10 and second magnetic material layer 20, thus significantly improving the intensity of the electrical pulse generated by the Weigand wire.

[0074] It can be understood that in the embodiments including multiple first magnetic material layers 10 and multiple second magnetic material layers 20, the coercivities of the first magnetic material layers 10 may be equal or not equal, but the coercivities of all the first magnetic material layers 10 should be greater than the coercivities of all the second magnetic material layers 20. Similarly, the coercivities of the second magnetic material layers 20 may be equal or not equal, but the coercivities of all the second magnetic material layers 20 should be less than the coercivities of all the first magnetic material layers 10.

[0075] In an embodiment of the present invention, the specific value of the coercivity of the first magnetic material layer 10 is not particularly limited, as long as it can ensure a clear demarcation line of the coercivity between the first magnetic material layer 10 and the second magnetic material layer 20. As some preferred solutions, the coercivity of the first magnetic material layer 10 can be 20 Oe - 100 Oe (for example, it can be 21 Oe, 30 Oe, 40 Oe, 50 Oe, 60 Oe, 70 Oe, 80 Oe, 90 Oe, 100 Oe, etc.).

[0076] Similarly, the specific value of the coercivity of the second magnetic material layer 20 is not particularly limited, as long as it can ensure a clear demarcation line of the coercivity between the first magnetic material layer 10 and the second magnetic material layer 20. As some preferred solutions, the coercivity of the second magnetic material layer 20 can be 10 Oe - 90 Oe (for example, it can be 10 Oe, 20 Oe, 30 Oe, 40 Oe, 50 Oe, 60 Oe, 70 Oe, 80 Oe, 89 Oe, etc.).

[0077] In an embodiment of the present invention, the material of the first magnetic material layer 10 is not particularly limited, as long as it has a coercivity that meets the requirements. As some specific examples, the material of the first magnetic material layer 10 can include at least one of Fe - Co - V alloy, Fe - Ni alloy, Fe - Si - B alloy, Fe - Co - Ni - Si - B alloy, Co - Fe - Mn - Si - B alloy, Ni - Zr alloy. For example, for the Fe - Co - V alloy, the mass content of Fe is 35%, the mass content of Co is 52%, and the mass content of V is 13%. Another example is the Fe - Ni alloy, where the mass content of Fe is 30% and the mass content of Ni is 70%. Another example is the Fe - Si - B alloy, where the mass content of Fe is 85% - 95%, the mass content of Si is 5% - 10%, and the mass content of B is 3%. Another example is the Ni - Zr alloy, where the mass content of Ni is 64% and the mass content of Zr is 36%. The toughness of the first magnetic material layer formed by the above materials can meet the usage requirements of the Weigand wire.

[0078] Similarly, the material of the second magnetic material layer 20 described above is not particularly limited as long as it has a coercivity that meets the requirements. As some specific examples, the material of the second magnetic material layer 20 may include at least one of Fe-Co-V alloy, Fe-Ni alloy, Fe-Si-B alloy, Fe-Co-Ni-Si-B alloy, Co-Fe-Mn-Si-B alloy, and Ni-Zr alloy. For example, in the Fe-Co-V alloy, the mass content of Fe is 35%, the mass content of Co is 52%, and the mass content of V is 13%. Another example is the Fe-Ni alloy, where the mass content of Fe is 30% and the mass content of Ni is 70%. Another example is the Fe-Si-B alloy, where the mass content of Fe is 85%-95%, the mass content of Si is 5%-10%, and the mass content of B is 3%. Another example is the Ni-Zr alloy, where the mass content of Ni is 64% and the mass content of Zr is 36%. The toughness of the second magnetic material layer formed by the above materials can meet the usage requirements of the Weigand wire.

[0079] In an embodiment of the present invention, the materials of the first magnetic material layer 10 and the second magnetic material layer 20 described above can independently adopt amorphous tapes or nanocrystalline tapes, and the thickness of the amorphous tapes or nanocrystalline tapes can be made very thin, thereby enabling the thicknesses of the first magnetic material layer 10 and the second magnetic material layer 20 to be very thin.

[0080] It should be noted that the coercivities of the first magnetic material layer 10 and the second magnetic material layer 20 are related not only to the constituent materials of the magnetic material layer but also to the preparation process of the magnetic material layer.

[0081] In an embodiment of the present invention, the specific values of the thickness of the first magnetic material layer 10 and the thickness of the second magnetic material layer 20 described above are not particularly limited. As some preferred solutions, the ratio of the thickness of the first magnetic material layer 10 to the thickness of the second magnetic material layer 20 can be (1:10)-(10:1). Further, the total thickness of the stacked Weigand wire can be greater than 20 μm and less than 1 mm, for example, it can be 30 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, etc.

[0082] According to some other specific embodiments of the present invention, refer to the attached Figure 4 , a bonding layer 30 is provided between the adjacent first magnetic material layer 10 and the second magnetic material layer 20. The bonding layer 30 is used to bond the first magnetic material layer 10 and the second magnetic material layer 20 so that the first magnetic material layer 10 and the second magnetic material layer 20 form a Weigand wire after being stacked.

[0083] In an embodiment of the present invention, on the premise that the adhesive layer 30 can firmly bond the adjacent first magnetic material layer 10 and second magnetic material layer 20, the smaller the thickness of the adhesive layer 30, the better. Preferably, the thickness of the adhesive layer 30 is less than the thickness of the first magnetic material layer 10 and less than the thickness of the second magnetic material layer 20. As some preferred solutions, the thickness of the adhesive layer 30 is less than 200 μm.

[0084] In an embodiment of the present invention, the material of the adhesive layer 30 is not particularly limited as long as it can bond the adjacent first magnetic material layer 10 and second magnetic material layer 20 together. As some specific examples, the material of the adhesive layer 30 may include at least one of thermosetting adhesives, photocuring adhesives, and natural curing adhesives. Thermosetting adhesives are preferred. Thermosetting adhesives not only have good adhesiveness (i.e., strong mechanical coupling), but also have good fluidity under non-curing conditions and can form a thinner adhesive layer 30. As some specific examples, thermosetting adhesives may include at least one of epoxy resin adhesives, phenolic resin adhesives, imino resin adhesives, and polyurethane resin adhesives, and epoxy resin adhesives are preferred.

[0085] In the related art, in the production process of the Weigand wire, the Villari alloy wire needs to undergo multi-cycle heat treatment and / or stress application. The purpose of the heat treatment and / or stress application is to gradually change the coercivity of the Villari alloy wire from the outside to the inside, and finally the required Weigand wire can be obtained. The complex production process results in extremely low production efficiency of the Weigand wire, and any parameter error in any link may lead to unqualified products in this batch. In addition, in the production process of the related art, a single long wire is processed at a time, and the wire length is generally greater than 1 m. During the processing, tensile force in the length direction needs to be applied. If there is a break at one place on a wire to be processed, the applied tensile stress and shear stress may become zero, resulting in the entire Weigand wire being unusable.

[0086] At the same time, the Weigand wire produced by the related production process is a slender cylinder, and its cross-section is approximately circular. The outer layer of the circle is a hard magnetic shell, and the inner layer is a soft magnetic core. The coercivity of the Weigand wire gradually changes from the outside to the inside, that is, there is no clear boundary between the coercivity of the outer hard magnetic shell and the inner soft magnetic core, resulting in a weak electric pulse generated by the existing Weigand wire.

[0087] To solve the above technical problems, in another aspect of the present invention, the present invention provides a method for preparing the above-mentioned Weigand wire. According to an embodiment of the present invention, the method includes: laminating at least one layer of a first magnetic material layer 10 and at least one layer of a second magnetic material layer 20, and the first magnetic material layer 10 and the second magnetic material layer 20 are alternately laminated, and the coercivity of the first magnetic material layer 10 is greater than that of the second magnetic material layer 20; bonding adjacent first magnetic material layer 10 and second magnetic material layer 20 together so that the adjacent first magnetic material layer 10 and second magnetic material layer 20 are bonded together. Thus, the method of the present invention directly alternately laminates the first magnetic material layer 10 and the second magnetic material layer 20, avoiding multiple cycles of heat treatment and stress application to the alloy wire in the prior art, thereby improving the production efficiency of the Weigand wire and solving the problem of low production efficiency of the Weigand wire. In addition, it avoids the problem that if there is a break in one wire to be processed in the existing method, the entire Weigand wire may not be usable, thereby improving the production efficiency of the Weigand wire. At the same time, there is a clear demarcation line in the coercivity between the first magnetic material layer 10 and the second magnetic material layer 20 of the Weigand wire prepared by the above method, thereby significantly increasing the intensity of the electrical pulse generated by the Weigand wire.

[0088] According to some specific embodiments of the present invention, referring to the attached Figure 7 , the method may include:

[0089] S100: Alternately laminate the first magnetic material layer and the second magnetic material layer on the first substrate

[0090] In this step, at least one layer of the first magnetic material layer 10 and at least one layer of the second magnetic material layer 20 are laminated on the first substrate 200, and the first magnetic material layer 10 and the second magnetic material layer 20 are alternately laminated. At the same time, during the alternate lamination of the first magnetic material layer 10 and the second magnetic material layer 20, an adhesive 31 is coated on at least a part of the surface of the first magnetic material layer 10 that fits the second magnetic material layer 20 and / or at least a part of the surface of the second magnetic material layer 20 that fits the first magnetic material layer 10, so as to bond the adjacent first magnetic material layer 10 and second magnetic material layer 20 together to form a laminated Weigand wire structure.

[0091] S200: Place a second substrate on the uppermost magnetic material layer

[0092] In this step, a second substrate 300 is placed on the uppermost magnetic material layer, and the laminated magnetic material layers are clamped between the first substrate 200 and the second substrate 300, as shown in the attached Figure 9 figure.

[0093] S300: Cure the adhesive

[0094] In this step, the adhesive 31 is cured to bond the adjacent first magnetic material layer 10 and second magnetic material layer 20. When the curing of the adhesive 31 is completed, the bonding between the adjacent first magnetic material layer 10 and second magnetic material layer 20 is completed.

[0095] In an embodiment of the present invention, the specific type of the above-mentioned adhesive 31 is not particularly limited as long as it can bond the adjacent first magnetic material layer 10 and second magnetic material layer 20 together. As some specific examples, the adhesive 31 may include at least one of a thermosetting adhesive, a photocurable adhesive, and a naturally curable adhesive. A thermosetting adhesive is preferred. The thermosetting adhesive not only has good adhesiveness (i.e., strong mechanical coupling), but also has good fluidity under non-curing conditions and can form a relatively thin bonding layer. As some specific examples, the thermosetting adhesive may include at least one of an epoxy resin adhesive, a phenolic resin adhesive, an imino resin adhesive, and a polyurethane resin adhesive, and an epoxy resin adhesive is preferred.

[0096] The curing method of the above-mentioned adhesive 31 depends on the specific type of the adhesive 31. For example, the thermosetting adhesive can be cured by heating, the photocurable adhesive can be cured by light irradiation, and the naturally curable adhesive can be naturally cured without other external conditions.

[0097] S400: Remove the first substrate and the second substrate

[0098] In this step, after the first magnetic material layer 10 and the second magnetic material layer 20 are bonded, the first substrate 200 and the second substrate 300 are removed to obtain a laminated structure.

[0099] During the lamination process of the first magnetic material layer 10 and the second magnetic material layer 20, an adhesive 31 with better fluidity is generally selected. Therefore, the adhesive 31 coated on the surface of the first magnetic material layer 10 and / or the second magnetic material layer 20 easily flows out of the laminated structure and firmly adheres to the first substrate and / or the second substrate, making it difficult to remove the first substrate and / or the second substrate.

[0100] To solve the above technical problems, according to some specific embodiments of the present invention, the first substrate may include a first plexiglass layer, a first silicone layer, and a first polytetrafluoroethylene film layer laminated in sequence, and the first polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer 10 or the second magnetic material layer 20. After the first magnetic material layer 10 and the second magnetic material layer 20 are bonded, the first substrate is removed from the laminated structure. The first polytetrafluoroethylene film layer in direct contact with the first magnetic material layer 10 or the second magnetic material layer 20 can be easily torn off from the laminated structure, and the adhesive 31 does not adhere to the surface of the first polytetrafluoroethylene film layer or the excess glue stains on the first polytetrafluoroethylene film layer can be easily removed.

[0101] Similarly, the second substrate may include a second polymethyl methacrylate layer, a second silicone layer, and a second polytetrafluoroethylene film layer stacked in sequence, and the second polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer 10 or the second magnetic material layer 20. After the bonding of the first magnetic material layer 10 and the second magnetic material layer 20 is completed, the second substrate is removed from the stacked structure. The second polytetrafluoroethylene film layer in direct contact with the first magnetic material layer 10 or the second magnetic material layer 20 can be easily torn off from the stacked structure, and the adhesive 31 does not adhere to the surface of the second polytetrafluoroethylene film layer or the excess glue stains on the second polytetrafluoroethylene film layer can be easily removed.

[0102] S500: Cut the stacked structure according to a preset size

[0103] In this step, the stacked structure is cut according to specific usage requirements to obtain a strip-shaped Weigand wire. As a specific example, the length of the Weigand wire required for manufacturing a Weigand sensor is generally about 10 mm, and the width is within 0.5 mm.

[0104] In the embodiments of the present invention, the above cutting method is not particularly limited. For example, laser cutting, electron beam cutting, or ion beam cutting can be used. The cutting speeds of the above several thermal cutting methods are all relatively fast, and the edges of the cut materials are relatively smooth.

[0105] According to some further specific embodiments of the present invention, refer to the attached Figure 8 , this method may further include between step S200 and step 300:

[0106] S250: Apply pressure between the first substrate and the second substrate

[0107] In this step, pressure is evenly applied between the first substrate and the second substrate to make the adhesive 31 between the first magnetic material layer 10 and the second magnetic material layer 20 as thin as possible. Keep this pressure and place the whole in a corresponding curing environment until the adhesive 31 is completely cured. Preferably, a pressure perpendicular to the first substrate and the second substrate is evenly applied between the first substrate and the second substrate.

[0108] According to the method for preparing the above-mentioned Weigand wire according to an embodiment of the present invention, the first magnetic material layer 10 with a certain coercivity and the second magnetic material layer 20 with a certain coercivity are directly stacked alternately, and the adjacent first magnetic material layer 10 and the second magnetic material layer 20 are bonded together, so that the adjacent first magnetic material layer 10 and the second magnetic material layer 20 are bonded together, thereby obtaining a Weigand wire with a laminated structure. The method of the present invention avoids multi-cycle heat treatment and stress application to alloy wires in the prior art, thereby improving the production efficiency of Weigand wires and solving the problem of low production efficiency of Weigand wires. In addition, during the preparation process of the Weigand wire of the present invention, the coercivities of the stacked first magnetic material layer 10 and the second magnetic material layer 20 are inherent to themselves, and no stress needs to be applied to them. Therefore, even if the obtained Weigand wire with a laminated structure is cut, it will not affect the coercivities of the first magnetic material layer 10 and the second magnetic material layer 20, thereby avoiding the problem that if there is a break in one place on a Weigand wire to be processed in the prior art, the entire Weigand wire may not be usable, thus improving the production efficiency of Weigand wires. At the same time, there is a clear demarcation line in the coercivities between the first magnetic material layer 10 and the second magnetic material layer 20 of the Weigand wire prepared by the above method, thereby significantly increasing the intensity of the electrical pulses generated by the Weigand wire.

[0109] In the third aspect of the present invention, the present invention proposes a Weigand sensor. According to an embodiment of the present invention, the Weigand sensor has the Weigand wire of the above embodiment or the Weigand wire prepared by the method of the above embodiment, and the coercivities of all the first magnetic material layers 10 are equal, and the coercivities of all the second magnetic material layers 20 are equal. Thus, by increasing the intensity of the electrical pulses generated by the Weigand wire, the accuracy of the Weigand sensor is improved.

[0110] In particular, the following three types of Weigand wires with laminated structures are suitable for Weigand sensors: 1) a single-layer laminated structure formed by the first magnetic material layer 10 and the second magnetic material layer 20; 2) a sandwich laminated structure formed by sequentially laminating the first magnetic material layer 10, the second magnetic material layer 20, and the first magnetic material layer 10, where the coercivities of the two first magnetic material layers 10 are equal; 3) a sandwich laminated structure formed by sequentially laminating the second magnetic material layer 20, the first magnetic material layer 10, and the second magnetic material layer 20, where the coercivities of the two second magnetic material layers 20 are equal.

[0111] The Weigand pulses generated by the Weigand effect are not related to time, so the Weigand sensor can be used as a counter in an environment with a magnetic excitation source around. In addition, for an ordinary Weigand sensor, each magnetic pulse can collect 20 nJ of energy, and 2 magnetic pulses are generated within each magnetic field cycle, so the Weigand sensor can also be used as an energy collector.

[0112] In the fourth aspect of the present invention, the present invention provides an energy harvester. According to an embodiment of the present invention, the energy harvester has the Weigand wire of the above embodiments or the Weigand wire prepared by the method of the above embodiments. Thus, by increasing the intensity of the electrical pulses generated by the Weigand wire, the efficiency of the energy harvester for collecting electrical energy is improved.

[0113] In an embodiment of the present invention, all laminated Weigand wires can be used in the energy harvester. The energy harvester captures the alternating magnetic energy in the environment by using the Weigand wire and a coil, and then converts it into electrical energy, which is then stored in the capacitor or battery of the circuit system.

[0114] Embodiments of the present invention will be described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention. Additionally, if not explicitly stated, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods. For the reaction conditions not listed, they are also easily obtained by those skilled in the art.

[0115] Example 1

[0116] This embodiment provides a Weigand wire, and the preparation process of the Weigand wire is as follows:

[0117] 1) Prepare a first magnetic material layer A1 with a coercivity of 30 Oe, a second magnetic material layer B with a coercivity of 15 Oe, and a first magnetic material layer A2 with a coercivity of 30 Oe. The materials of the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 are all Fe-Co-V alloys, where the mass content of Fe is 35%, the mass content of Co is 52%, and the mass content of V is 13%. And the thickness ratio of the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 is 1:1:1.

[0118] 2) Stack the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 on the first substrate in sequence, and epoxy resin glue is coated between the first magnetic material layer A1 and the second magnetic material layer B and between the second magnetic material layer B and the first magnetic material layer A2. Among them, the first substrate includes a first plexiglass layer, a first silica gel layer, and a first polytetrafluoroethylene film layer stacked in sequence, and the first polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer A1.

[0119] Then, place the second substrate on the first magnetic material layer A2. The second substrate includes a second plexiglass layer, a second silica gel layer, and a second polytetrafluoroethylene film layer stacked in sequence, and the second polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer A2. Apply a vertically downward pressure uniformly to the second substrate to make the epoxy resin colloid between the first magnetic material layer A1 and the second magnetic material layer B and between the second magnetic material layer B and the first magnetic material layer A2 as thin as possible. Maintain this pressure and place the whole in the corresponding temperature environment until the epoxy resin glue is completely cured.

[0120] 3) Take out the laminated structure. The total thickness of the laminated structure is 300 μm. Use a laser to cut the laminated structure into Wiegand wires in the shape of thin strips with a length of about 10 mm and a width of about 0.5 mm.

[0121] Example 2

[0122] This example provides a Wiegand wire. The difference between this example and Example 1 is only that:

[0123] The coercivity of the first magnetic material layer A1 is 50 Oe, the coercivity of the second magnetic material layer B is 20 Oe, and the coercivity of the first magnetic material layer A1 is 50 Oe. The materials of the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 are all Fe-Ni alloys, where the mass content of Fe is 30%, and the mass content of Ni is 70%. And the thickness ratio of the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 is 1:2:1.

[0124] Other contents are the same as those in Example 1.

[0125] Example 3

[0126] This example provides a Wiegand wire. The difference between this example and Example 1 is only that:

[0127] The coercivity of the first magnetic material layer A1 is 70 Oe, the coercivity of the second magnetic material layer B is 30 Oe, and the coercivity of the first magnetic material layer A2 is 65 Oe. The materials of the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 are all Fe-Si-B alloys, where the mass content of Fe is 90%, the mass content of Si is 7%, and the mass content of B is 3%. And the thickness ratio of the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 is 1:5:1.

[0128] Other contents are the same as those in Example 1.

[0129] Example 4

[0130] This example provides a Wiegand wire. The difference between this example and Example 1 is only that:

[0131] The coercivity of the first magnetic material layer A1 is 90 Oe, the coercivity of the second magnetic material layer B is 40 Oe, and the coercivity of the first magnetic material layer A2 is 85 Oe. The materials of the first magnetic material layer A1 and the first magnetic material layer A2 are both Fe-Si-B alloys, where the mass content of Fe is 90%, the mass content of Si is 7%, and the mass content of B is 3%. The material of the second magnetic material layer B is a Ni-Zr alloy, where the mass content of Ni is 64% and the mass content of Zr is 36%. And the thickness ratio of the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 is 2:1:2.

[0132] All other contents are the same as those in Example 1.

[0133] Example 5

[0134] This example provides a Weigand wire. The difference between this example and Example 1 is only that:

[0135] The coercivity of the first magnetic material layer A1 is 90 Oe, the coercivity of the second magnetic material layer B is 60 Oe, and the coercivity of the first magnetic material layer A2 is 85 Oe. The materials of the first magnetic material layer A1 and the first magnetic material layer A2 are both Fe-Co-V alloys, where the mass content of Fe is 35%, the mass content of Co is 52%, and the mass content of V is 13%. The material of the second magnetic material layer B is an Fe-Ni alloy, where the mass content of Fe is 30% and the mass content of Ni is 70%. And the thickness ratio of the first magnetic material layer A1, the second magnetic material layer B, and the first magnetic material layer A2 is 5:1:5.

[0136] All other contents are the same as those in Example 1.

[0137] Example 6

[0138] This example provides a Weigand wire. The difference between this example and Example 1 is only that:

[0139] The coercivity of the first magnetic material layer A1 is 100 Oe, the coercivity of the second magnetic material layer B is 80 Oe, and the coercivity of the first magnetic material layer A1 is 100 Oe.

[0140] All other contents are the same as those in Example 1.

[0141] Example 7

[0142] This example provides a Weigand wire. The preparation process of this Weigand wire is as follows:

[0143] 1) Prepare a second magnetic material layer B1 with a coercivity of 20 Oe, a first magnetic material layer A with a coercivity of 50 Oe, and a second magnetic material layer B2 with a coercivity of 20 Oe. The materials of the second magnetic material layer B1, the first magnetic material layer A, and the second magnetic material layer B2 are all Fe-Co-V alloys, where the mass content of Fe is 35%, the mass content of Co is 52%, and the mass content of V is 13%. Moreover, the thickness ratio of the second magnetic material layer B1, the first magnetic material layer A, and the second magnetic material layer B2 is 1:1:1.

[0144] 2) Stack the second magnetic material layer B1, the first magnetic material layer A, and the second magnetic material layer B2 in sequence on a first substrate, and apply an imino resin adhesive between the second magnetic material layer B1 and the first magnetic material layer A, and between the first magnetic material layer A and the second magnetic material layer B2. Among them, the first substrate includes a first plexiglass layer, a first silicone layer, and a first polytetrafluoroethylene film layer stacked in sequence, and the first polytetrafluoroethylene film layer is in direct contact with the second magnetic material layer B1.

[0145] Then place a second substrate on the second magnetic material layer B2. The second substrate includes a second plexiglass layer, a second silicone layer, and a second polytetrafluoroethylene film layer stacked in sequence, and the second polytetrafluoroethylene film layer is in direct contact with the second magnetic material layer B2. Apply a vertically downward pressure uniformly to the second substrate to make the imino resin adhesive between the second magnetic material layer B1 and the first magnetic material layer A, and between the first magnetic material layer A and the second magnetic material layer B2 as thin as possible. Keep this pressure and place the whole in the corresponding temperature environment until the imino resin adhesive is completely cured.

[0146] 3) Take out the stacked structure. The total thickness of the stacked structure is 500 μm. Use a laser to cut the stacked structure into fine strip-shaped Weigand wires with a length of about 10 mm and a width of about 0.5 mm.

[0147] Example 8

[0148] This example provides a Weigand wire. The difference between this example and Example 1 is only that:

[0149] The coercivity of the second magnetic material layer B1 is 40 Oe, the coercivity of the first magnetic material layer A is 70 Oe, and the coercivity of the second magnetic material layer B2 is 35 Oe. The materials of the second magnetic material layer B1, the first magnetic material layer A, and the second magnetic material layer B2 are all Fe-Ni alloys, where the mass content of Fe is 30% and the mass content of Ni is 70%.

[0150] Other contents are the same as those in Example 7.

[0151] Example 9

[0152] This embodiment provides a Weigand wire. The difference between this embodiment and Embodiment 1 is only that:

[0153] The coercivity of the second magnetic material layer B1 is 50 Oe, the coercivity of the first magnetic material layer A is 90 Oe, and the coercivity of the second magnetic material layer B2 is 55 Oe. The materials of the second magnetic material layer B1 and the second magnetic material layer B2 are both Fe-Si-B alloys, where the mass content of Fe is 90%, the mass content of Si is 7%, and the mass content of B is 3%. The material of the first magnetic material layer A is a Ni-Zr alloy, where the mass content of Ni is 64% and the mass content of Zr is 36%.

[0154] All other contents are the same as those in Embodiment 7.

[0155] Embodiment 10

[0156] This embodiment provides a Weigand wire. The preparation process of this Weigand wire is as follows:

[0157] 1) Prepare a first magnetic material layer A with a coercivity of 40 Oe and a second magnetic material layer B with a coercivity of 20 Oe. The materials of the first magnetic material layer A and the second magnetic material layer B are both Fe-Co-V alloys, where the mass content of Fe is 35%, the mass content of Co is 52%, and the mass content of V is 13%. And the thickness ratio of the first magnetic material layer A to the second magnetic material layer B is 5:1.

[0158] 2) Stack the first magnetic material layer A and the second magnetic material layer B on the first substrate in sequence, and apply epoxy resin glue between the first magnetic material layer A and the second magnetic material layer B. Among them, the first substrate includes a first plexiglass layer, a first silica gel layer, and a first polytetrafluoroethylene film layer stacked in sequence, and the first polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer A.

[0159] Then place a second substrate on the second magnetic material layer B. The second substrate includes a second plexiglass layer, a second silica gel layer, and a second polytetrafluoroethylene film layer stacked in sequence, and the second polytetrafluoroethylene film layer is in direct contact with the second magnetic material layer B. Apply a vertically downward pressure evenly to the second substrate to make the epoxy resin colloid between the first magnetic material layer A and the second magnetic material layer B as thin as possible. Keep this pressure and place the whole in the corresponding temperature environment until the epoxy resin glue is cured.

[0160] 3) Take out the stacked structure. The total thickness of the stacked structure is 100 μm. Use a laser to cut the stacked structure into thin strips of Weigand wire with a length of about 10 mm and a width of about 0.5 mm.

[0161] Embodiment 11

[0162] This embodiment provides a Weigand wire. The difference between this embodiment and Embodiment 1 is only that:

[0163] The coercivity of the first magnetic material layer A is 60 Oe, and the coercivity of the second magnetic material layer B is 30 Oe. The thickness ratio of the first magnetic material layer A to the second magnetic material layer B is 2:1.

[0164] All other contents are the same as those in Embodiment 10.

[0165] Embodiment 12

[0166] This embodiment provides a Weigand wire. The difference between this embodiment and Embodiment 1 is only that:

[0167] The coercivity of the first magnetic material layer A is 70 Oe, and the coercivity of the second magnetic material layer B is 35 Oe. The thickness ratio of the first magnetic material layer A to the second magnetic material layer B is 1:1.

[0168] All other contents are the same as those in Embodiment 10.

[0169] Embodiment 13

[0170] This embodiment provides a Weigand wire. The difference between this embodiment and Embodiment 1 is only that:

[0171] The coercivity of the first magnetic material layer A is 80 Oe, and the coercivity of the second magnetic material layer B is 40 Oe. The thickness ratio of the first magnetic material layer A to the second magnetic material layer B is 1:2.

[0172] All other contents are the same as those in Embodiment 10.

[0173] Embodiment 14

[0174] This embodiment provides a Weigand wire. The difference between this embodiment and Embodiment 1 is only that:

[0175] The coercivity of the first magnetic material layer A is 100 Oe, and the coercivity of the second magnetic material layer B is 50 Oe. The thickness ratio of the first magnetic material layer A to the second magnetic material layer B is 1:5.

[0176] All other contents are the same as those in Embodiment 10.

[0177] Embodiment 15

[0178] This embodiment provides a Weigand wire. The preparation process of the Weigand wire is as follows:

[0179] 1) Prepare a first magnetic material layer A1 with a coercivity of 40 Oe, a second magnetic material layer B1 with a coercivity of 20 Oe, a first magnetic material layer A2 with a coercivity of 40 Oe, and a second magnetic material layer B2 with a coercivity of 20 Oe. The materials of the first magnetic material layer A1, the second magnetic material layer B1, the first magnetic material layer A2, and the second magnetic material layer B2 are all Fe-Co-V alloys, where the mass content of Fe is 35%, the mass content of Co is 52%, and the mass content of V is 13%. And the thickness ratio of the first magnetic material layer A1, the second magnetic material layer B1, the first magnetic material layer A2, and the second magnetic material layer B2 is 1:1:1:1.

[0180] 2) Stack the first magnetic material layer A1, the second magnetic material layer B1, the first magnetic material layer A2, and the second magnetic material layer B2 in sequence on the first substrate, and apply epoxy resin glue between the first magnetic material layer A1 and the second magnetic material layer B1, between the second magnetic material layer B1 and the first magnetic material layer A2, and between the first magnetic material layer A2 and the second magnetic material layer B2. Among them, the first substrate includes a first plexiglass layer, a first silica gel layer, and a first polytetrafluoroethylene film layer stacked in sequence, and the first polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer A1.

[0181] Then place a second substrate on the second magnetic material layer B2. The second substrate includes a second plexiglass layer, a second silica gel layer, and a second polytetrafluoroethylene film layer stacked in sequence, and the second polytetrafluoroethylene film layer is in direct contact with the second magnetic material layer B2. Apply a vertically downward pressure evenly to the second substrate to make the epoxy resin colloid between the layers as thin as possible. Maintain this pressure and place the whole in the corresponding temperature environment until the epoxy resin glue is completely cured.

[0182] 3) Take out the stacked structure. The total thickness of the stacked structure is 700 μm. Use a laser to cut the stacked structure into a Weigand wire in the shape of a thin strip with a length of about 10 mm and a width of about 0.5 mm.

[0183] Example 16

[0184] This example provides a Weigand wire. The difference between this example and Example 1 is only that:

[0185] The coercivity of the first magnetic material layer A1 is 60 Oe, the coercivity of the second magnetic material layer B1 is 30 Oe, the coercivity of the first magnetic material layer A2 is 65 Oe, and the coercivity of the second magnetic material layer B2 is 30 Oe.

[0186] Other contents are the same as those in Example 15.

[0187] Example 17

[0188] This embodiment provides a Weigand wire. The difference between this embodiment and Embodiment 1 is only that:

[0189] The coercivity of the first magnetic material layer A1 is 80 Oe, the coercivity of the second magnetic material layer B1 is 40 Oe, the coercivity of the first magnetic material layer A2 is 85 Oe, and the coercivity of the second magnetic material layer B2 is 45 Oe.

[0190] All other contents are the same as those in Embodiment 15.

[0191] Embodiment 18

[0192] This embodiment provides a Weigand wire. The difference between this embodiment and Embodiment 1 is only that:

[0193] The coercivity of the first magnetic material layer A1 is 100 Oe, the coercivity of the second magnetic material layer B1 is 50 Oe, the coercivity of the first magnetic material layer A2 is 95 Oe, and the coercivity of the second magnetic material layer B2 is 55 Oe.

[0194] All other contents are the same as those in Embodiment 15.

[0195] Comparative Example 1

[0196] This embodiment provides a Weigand wire. The preparation process of the Weigand wire is as follows:

[0197] 1) Provide a Fe 0.48 Ni 0.52 alloy wire with a diameter of 10 mil and a length of 1 m;

[0198] 2) Stretch it, and the stretching ratio is 4%;

[0199] 3) Apply a tensile force of 450 g to the Fe 0.48 Ni 0.52 alloy wire;

[0200] 4) At the same time, rotate the alloy wire forward and backward, with the number of rotation turns being 0.4 turns / cm, and repeat the forward and backward rotation 30 - 50 times;

[0201] 5) Remove the applied tension, end the process, and cut the Weigand wire into pieces with a length of about 10 mm.

[0202] Induction coils were wound around the Weigand wires prepared in Examples 1-18 and Comparative Example 1 respectively, and then an alternating magnetic field was applied to each of them to generate pulses. The process was as follows: 1) The initial magnetic field was zero. As the applied magnetic field increased, both the first magnetic material layer and the second magnetic material layer were magnetized in the positive direction; 2) A magnetic field was applied in the reverse direction. The first magnetic material layer was first magnetized in the reverse direction. When the reverse magnetic field increased to the trigger magnetic induction intensity (i.e., when the second magnetic material layer was also magnetized in the reverse direction), the magnetic field in the space around the Weigand wire also changed instantaneously, and thus an electrical pulse was induced in the induction coil; 3) Similarly, a magnetic field was applied in the positive direction. The first magnetic material layer was first magnetized in the positive direction. When the positive magnetic field increased to the trigger magnetic induction intensity (i.e., when the second magnetic material layer was also magnetized in the positive direction), the magnetization direction of the Weigand wire instantaneously flipped again, and an electrical pulse with the opposite direction was induced in the induction coil. The test results showed that, compared with Comparative Example 1, the intensities of the electrical pulses generated by the Weigand wires prepared in Examples 1-18 were all significantly improved.

[0203] In addition, compared with Comparative Example 1, the preparation method of the Weigand wire provided in Examples 1-18 directly laminated the first magnetic material layer and the second magnetic material layer alternately, avoiding the multi-cycle stress application to the alloy wire in Comparative Example 1, thereby improving the production efficiency of the Weigand wire and solving the problem of low production efficiency of the Weigand wire.

[0204] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without conflict, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples.

[0205] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A Wiegand wire, characterized in that: include: At least one first magnetic material layer and at least one second magnetic material layer, the first magnetic material layer and the second magnetic material layer are alternately stacked in a direction perpendicular to the length of the Wiegand wire, and the coercive force of the first magnetic material layer is greater than the coercive force of the second magnetic material layer.

2. The Wiegand wire according to claim 1, characterized in that: The difference between the coercivity of the first magnetic material layer and the coercivity of the second magnetic material layer is greater than 10 Oe.

3. The Wiegand wire according to claim 2, characterized in that: The difference between the coercivity of the first magnetic material layer and the coercivity of the second magnetic material layer is 20 Oe-60 Oe.

4. The Wiegand wire according to claim 1, characterized in that: The first magnetic material layer and the second magnetic material layer are stacked in sequence, wherein the first magnetic material layer and the second magnetic material layer form a single stack; Alternatively, the method comprises the first magnetic material layer, the second magnetic material layer and the first magnetic material layer which are stacked in sequence; Alternatively, the method comprises the second magnetic material layer, the first magnetic material layer and the second magnetic material layer which are stacked in sequence; Alternatively, it includes a plurality of first magnetic material layers and a plurality of second magnetic material layers, and the first magnetic material layers and the second magnetic material layers are alternately stacked.

5. The Wiegand wire according to any one of claims 1 to 4, characterized in that: The coercive force of the first magnetic material layer is 20Oe-100Oe; And / or, the coercive force of the second magnetic material layer is 10 Oe-90 Oe.

6. The Wiegand wire according to any one of claims 1 to 4, characterized in that: The first magnetic material layer includes at least one of Fe-Co-V alloy, Fe-Ni alloy, Fe-Si-B alloy, Fe-Co-Ni-Si-B alloy, Co-Fe-Mn-Si-B alloy, and Ni-Zr alloy; And / or, the second magnetic material layer includes at least one of Fe-Co-V alloy, Fe-Ni alloy, Fe-Si-B alloy, Fe-Co-Ni-Si-B alloy, Co-Fe-Mn-Si-B alloy, and Ni-Zr alloy.

7. The Wiegand wire according to any one of claims 1 to 4, characterized in that: The ratio of the thickness of the first magnetic material layer to the thickness of the second magnetic material layer is (1:10)-(10:1).

8. The Wiegand wire according to claim 7, characterized in that: The total thickness of the stacked Wiegand yarns is greater than 20 μm and less than 1 mm.

9. The Wiegand wire according to any one of claims 1 to 4, characterized in that: An adhesive layer is provided between the adjacent first magnetic material layer and the second magnetic material layer, and the adhesive layer is used to adhere the first magnetic material layer and the second magnetic material layer.

10. The Wiegand wire according to claim 9, characterized in that: The thickness of the adhesive layer is smaller than the thickness of the first magnetic material layer, and the thickness of the adhesive layer is smaller than the thickness of the second magnetic material layer.

11. The Wiegand wire according to claim 10, characterized in that: The thickness of the adhesive layer is less than 200 μm.

12. The Wiegand wire according to claim 9, characterized in that: The adhesive layer includes at least one of a heat-curing adhesive, a light-curing adhesive and a natural-curing adhesive.

13. The Wiegand wire according to claim 12, characterized in that: The heat-curing adhesive includes at least one of epoxy resin adhesive, phenolic resin adhesive, imino resin adhesive and polyurethane resin adhesive.

14. A method for preparing Wiegand silk, characterized in that: include: stacking at least one first magnetic material layer and at least one second magnetic material layer, wherein the first magnetic material layers and the second magnetic material layers are stacked alternately, and the coercive force of the first magnetic material layer is greater than the coercive force of the second magnetic material layer; Bonding the adjacent first magnetic material layers and the second magnetic material layers so that the adjacent first magnetic material layers and the second magnetic material layers are bonded together to obtain a stacked structure; The stacked structure is cut according to a preset size to obtain Wiegand wire.

15. The method according to claim 14, characterized in that include: At least one first magnetic material layer and at least one second magnetic material layer are stacked on a first substrate, and the first magnetic material layers and the second magnetic material layers are stacked alternately, and an adhesive is applied to at least a portion of the surface of the first magnetic material layer that is in contact with the second magnetic material layer and / or at least a portion of the surface of the second magnetic material layer that is in contact with the first magnetic material layer; placing a second substrate on the uppermost magnetic material layer; curing the adhesive to bond the adjacent first magnetic material layer and the second magnetic material layer; After the first magnetic material layer and the second magnetic material layer are bonded, the first substrate and the second substrate are removed to obtain the stacked structure; The stacked structure is cut according to a preset size to obtain the Wiegand wire.

16. The method according to claim 15, characterized in that Before curing the adhesive, the method further comprises: Pressure is applied between the first substrate and the second substrate.

17. The method according to claim 15 or 16, characterized in that The adhesive includes at least one of a heat-curing adhesive, a light-curing adhesive and a natural-curing adhesive.

18. The method according to claim 15 or 16, characterized in that The first substrate includes a first organic glass layer, a first silicone layer and a first polytetrafluoroethylene film layer stacked in sequence, and the first polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer or the second magnetic material layer.

19. The method according to claim 15 or 16, characterized in that The second substrate includes a second organic glass layer, a second silicone layer, and a second polytetrafluoroethylene film layer stacked in sequence, and the second polytetrafluoroethylene film layer is in direct contact with the first magnetic material layer or the second magnetic material layer.

20. A Wiegand sensor, characterized in that: A Wiegand wire according to any one of claims 1 to 13 or a Wiegand wire prepared by the method according to any one of claims 14 to 19, wherein the coercive forces of all the first magnetic material layers are equal, and the coercive forces of all the second magnetic material layers are equal.

21. An energy collector, characterized in that: A Wiegand wire according to any one of claims 1 to 13 or a Wiegand wire prepared by the method according to any one of claims 14 to 19.

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