Magnetostriction measuring device for amorphous alloy single sheet and use method thereof

Abstract

The invention belongs to the field of amorphous alloy magnetic property measurement, and particularly relates to a magnetostriction measurement device for an amorphous alloy single sheet and a use method of the magnetostriction measurement device. Comprising a fixing device and a measuring system, the fixing device is used for fixing an amorphous alloy single sheet and applying a magnetic field to the amorphous alloy single sheet, the measuring system is used for measuring the magnetostriction characteristic of the amorphous alloy single sheet in the magnetic field by adopting a triaxial strain gauge method, the fixing device is provided with a base frame base and two supporting blocks, and an iron yoke is inserted between the two supporting blocks; a Helmholtz excitation coil is sleeved outside the amorphous alloy single sheet positioned inside the iron yoke, and an anti-bending clamp is sleeved on the amorphous alloy single sheet positioned inside the iron yoke; and low-pressure elastic clamps for clamping the two ends of the amorphous alloy single sheet are arranged at the two ends of the amorphous alloy single sheet. The device is simple in structure, low in cost and easy to operate, spontaneous deformation of the amorphous alloy single sheet to be measured in the measurement process can be reduced to a great extent, and the magnetostriction characteristic measurement accuracy of the amorphous alloy single sheet is improved.

Description

Technical Field

[0001] The present invention belongs to the field of measurement of magnetic properties of amorphous alloys, and particularly relates to a magnetostriction measurement device for an amorphous alloy single sheet and a method for using the same. Background Art

[0002] The traditional soft magnetic material for the core of power transformers is oriented silicon steel. With the energy conservation, light weight of power equipment and the technological breakthrough of ferromagnetic materials, amorphous alloys, as a new type of soft magnetic material with good prospects, are widely used in the manufacture of the cores of distribution transformers, which can significantly reduce the no-load loss and excitation power of transformers. The magnetostriction phenomenon of soft magnetic materials refers to the fact that under the action of an alternating magnetic field, the size of soft magnetic materials will periodically elongate or shorten with the change of the magnetic field. The magnetostriction phenomenon will cause vibration noise of the cores of electrical equipment such as power transformers and motors. Although amorphous alloy transformers have the advantage of low no-load loss, their magnetostriction coefficient is relatively large. The relatively high magnetostriction coefficient, combined with the sensitivity of the electromagnetic performance of the amorphous alloy transformer core to stress and the relatively low stacking factor, results in relatively large vibration of the core during operation. The relatively large vibration will cause damage to the transformer structure and unstable operation problems, thus affecting the safety of the power system. At the same time, the environmental noise pollution caused thereby has also become a hot issue in the industry. In order to accurately evaluate the deformation and noise caused by magnetostriction of the amorphous alloy transformer core at the design stage of electrical equipment, it is necessary to accurately predict the magnetostriction effect of amorphous alloy strips. Therefore, the accurate measurement of the magnetostriction characteristics of amorphous alloys is particularly important.

[0003] Due to the thin and brittle material characteristics of the amorphous alloy single sheet, it increases the difficulty of magnetostriction measurement. However, currently, the measurement devices for amorphous alloy single sheets generally follow the measurement devices for electrical steel sheets. When performing magnetostriction measurement, it is difficult to maintain the fixed shape of the amorphous alloy single sheet, which affects the measurement accuracy. Therefore, it is necessary to improve the existing measurement device to improve the measurement accuracy. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a magnetostriction measurement device for an amorphous alloy single sheet and a method for using the same, aiming to suppress the bending deformation of the amorphous alloy single sheet during the process of magnetostriction measurement of the amorphous alloy single sheet, thereby reducing the measurement error, providing a solution for accurately measuring the magnetostriction characteristics of the amorphous alloy single sheet strip, and helping to understand the intrinsic characteristics of the amorphous alloy strip material and master the magnetostriction mechanism of the amorphous alloy strip.

[0005] The technical solution of the present invention is: a magnetostriction measuring device for an amorphous alloy single sheet, comprising: a fixing device for fixing the amorphous alloy single sheet and applying a magnetic field to the amorphous alloy single sheet and a measuring system for measuring the magnetostriction characteristics of the amorphous alloy single sheet under a magnetic field by using a triaxial strain gauge method, the fixing device comprising: a base frame and two support blocks fixedly arranged on the base frame, an iron yoke inserted between the two support blocks, the iron yoke comprising a first U-shaped iron yoke and a second U-shaped iron yoke butted with a U-shaped opening end of the first U-shaped iron yoke, an amorphous alloy single sheet is arranged at the butt joint of the first U-shaped iron yoke and the second U-shaped iron yoke; a Helmholtz excitation coil is sleeved on the outside of the amorphous alloy single sheet located inside the iron yoke, and the Helmholtz excitation coil is supported on two support blocks;

[0006] An anti-bending fixture is sleeved on the outside of the amorphous alloy single piece located inside the iron yoke, a through hole is provided on the top of the anti-bending fixture, and a support frame supported on the base of the base frame is provided on the bottom of the anti-bending fixture;

[0007] Two ends of the amorphous alloy single piece located outside the iron yoke are provided with low-pressure elastic clamps fixedly arranged on the base of the base frame for clamping the two ends of the amorphous alloy single piece.

[0008] Furthermore, the anti-bending clamp includes: an upper cover plate and a lower base slidably connected thereto, wherein sliders are fixedly arranged on both sides of the upper cover plate, and sliding grooves matching the sliders are correspondingly arranged on both sides of the lower base, a through hole is opened on the upper cover plate, and a support frame is fixedly arranged at the bottom of the lower base.

[0009] Furthermore, the anti-bending clamp is made of polyetheretherketone.

[0010] Furthermore, the low-pressure elastic clamp includes a support fixedly connected to the base of the frame by bolts, a vertical pole is fixedly arranged on the support, a lower clip is fixedly connected to the vertical pole by multiple first bolts, an upper clip slidably mounted on the vertical pole is provided above the lower clip, and threaded holes are correspondingly provided on the upper clip and the lower clip, and the threaded holes connect the upper clip and the lower clip by cooperating with second bolts.

[0011] Furthermore, the upper layer clip and the lower layer clip are made of silicone.

[0012] Furthermore, a laser displacement sensor system for detecting the flatness of the amorphous alloy single piece is detachably arranged on the two supporting blocks.

[0013] Furthermore, the laser displacement sensor system includes: a slide rail and a sensor slidably arranged on the slide rail, wherein the slide rail is located above and parallel to the amorphous alloy single sheet, both ends of the slide rail are fixedly connected to an L-shaped support rod, the bottom end of the L-shaped support rod is provided with a socket, and is plugged into a plug block arranged on the support block.

[0014] Further, the material of the slide rail is polyether ether ketone.

[0015] Further, the measurement system includes: a triaxial strain gauge, a strain bridge box, a strain amplifier, a BNC adapter, a data acquisition card, and a computer, wherein:

[0016] The triaxial strain gauge is pasted on the single amorphous alloy sheet, and is used to convert the deformation signal of the single amorphous alloy sheet under the magnetic field into a resistance change signal;

[0017] The strain bridge box is used to convert the resistance change signal of the triaxial strain gauge into a voltage change signal;

[0018] The strain amplifier is used to amplify the voltage change signal;

[0019] The BNC adapter is used to convert the amplified voltage change signal into a digital signal;

[0020] The data acquisition card is used to transmit the digital signal into the computer;

[0021] The computer uses the LabVIEW control program to realize the measurement and processing of the digital signal.

[0022] In addition, the present invention also provides a usage method of the above magnetic striction measurement device for a single amorphous alloy sheet, including the following steps:

[0023] Step 1: Pretreat the single amorphous alloy sheet to be measured;

[0024] Prepare the single amorphous alloy sheet to be measured, ensure that its surface is flat and defect-free, cut it according to the dimensions of the yoke and the anti-bending fixture in the measurement device so that the length of the single amorphous alloy sheet is sufficient for clamping by the low-pressure elastic fixture, and the width is the same as the width of the yoke. Spray degreasing liquid on the single amorphous alloy sheet, wipe the measurement area clean with a cotton swab, apply special strain gauge adhesive on the measurement area, then paste the triaxial strain gauge on the test area, and keep the angles between the triaxial strain gauge and the single amorphous alloy sheet in the horizontal direction at 0°, 45°, and 90° respectively. Let it stand for about 1 min, and press the adhesive between the triaxial strain gauge and the single amorphous alloy sheet with finger force, and maintain the pressure for 2 min;

[0025] Step 2: Assemble the single amorphous alloy sheet onto the fixing device;

[0026] First, remove the second U-shaped yoke, pass the lower base of the anti-bending fixture through the Helmholtz excitation coil and fix it on the base frame base 1, then pass the single amorphous alloy sheet to be measured with the triaxial strain gauge pasted through the Helmholtz excitation coil, and place it flat on the lower base of the anti-bending fixture;

[0027] Secondly, fixedly install the low-pressure elastic clamps at both ends of the first U-shaped yoke on the base frame base to ensure firm fixation without left-right shaking to cause measurement errors. By adjusting the screw tightness of the second bolt between the upper clamping piece and the lower clamping piece, apply a pre-tightening force to the amorphous alloy single piece to be measured, and then ensure that the sample piece remains horizontal and flat without bending through the anti-bending clamp;

[0028] Thirdly, install two laser displacement sensor systems on the support blocks of the base frame base. Align the plug blocks on the upper surface of the support blocks with the sockets at the bottom ends of the L-shaped support rods of the laser displacement sensor systems to install firmly. The upper cover plate has reserved square through holes, and use two laser displacement sensors to measure four measurement points of the amorphous alloy single piece at the exposed through holes respectively, and compare the data of the two laser displacement sensors to verify the flatness of the amorphous alloy single piece;

[0029] Step 3: Start the test;

[0030] Set the excitation frequency to the power frequency of 50 Hz to study the magnetostrictive characteristics of the amorphous alloy at the power frequency. During the measurement process, since the saturation magnetic flux density of the amorphous alloy single piece is about 1.5 T, the peak magnetic flux density B max gradually increases from 0.5 T to 1.5 T with a step size of 0.1 T. In order to reduce the measurement error, the strain signal measurement process is repeated 5 times and averaged, and the magnetostrictive curve is plotted based on the obtained data to analyze the magnetostrictive characteristics of the amorphous alloy.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The present invention improves the measurement accuracy. The thickness of the amorphous alloy single piece is small and has a large hardness. The thickness of the single strip is only 0.02 - 0.03 mm. When performing magnetostrictive measurement, it is difficult for it to maintain a fixed shape, which increases the measurement difficulty and leads to inaccurate measurement. The present invention designs an anti-bending clamp and a low-pressure elastic clamp made of polyether ether ketone, and adjusts the flatness of the amorphous alloy single piece through the laser displacement sensor system, greatly reducing the spontaneous deformation of the amorphous alloy single piece to be measured during the measurement process. The present invention also uses a Helmholtz coil to generate a uniform magnetic field (non-uniformity < 1%), reducing the torque bending caused by the gradient magnetic field, excluding interference and improving the measurement accuracy without affecting the magnetostrictive characteristics of the material;

[0033] (2) The present invention can achieve vector magnetostriction measurement. Since the existing measurement methods for the magnetostrictive characteristics of single amorphous alloy sheets mostly use the laser vibration measurement method, although the laser vibrometer has high precision, it can only measure the magnetostrictive deformation along the magnetization direction. The present invention adopts the three-axis strain method, which can achieve magnetostriction measurement in any direction within the plane, helping to comprehensively analyze the vector characteristics of the magnetostriction of amorphous alloys, understand the magnetostriction mechanism of amorphous alloys. In addition, the magnetostriction data measured by the three-axis strain gauge can be used to establish the magnetostriction model of the material, providing reference data for the coupling simulation of the electromagnetic field and the magnetostrictive force field, thus having guiding significance for optimizing the material properties of amorphous alloys;

[0034] (3) The present invention has low cost and is easy to operate. The materials used in the designed anti-bending clamp, low-pressure elastic clamp and laser displacement sensor system of the present invention, such as medical-grade silica gel, aluminum alloy, polyether ether ketone, etc., all have low costs and are easily obtainable in the laboratory, and the experimental operation system is designed to be easy to get started.

[0035] (4) The device of the present invention has high versatility. Other soft magnetic materials, such as iron-aluminum alloy, nanocrystalline alloy, etc., can also use the designed anti-bending clamp, low-pressure elastic clamp and laser displacement sensor system of the present invention when measuring the magnetostrictive characteristics to reduce the influence of spontaneous deformation on the measurement accuracy;

[0036] (5) The programmability and modular design of LabVIEW adopted by the present invention enable the measurement system to be flexibly adjusted and expanded according to different experimental requirements. For example, new measurement channels or functional modules can be conveniently added to meet the measurement requirements under complex experimental conditions. Description of the Drawings

[0037] Figure 1 is the overall structural schematic diagram of the fixing device of the present invention;

[0038] Figure 2 is the structural schematic diagram of the base of the present invention;

[0039] Figure 3 is the structural schematic diagram of the exciting part of the present invention;

[0040] Figure 4 is the structural schematic diagram of the anti-bending fixture of the present invention;

[0041] Figure 5 is the structural schematic diagram of the low-pressure elastic fixture of the present invention;

[0042] Figure 6 is the structural schematic diagram of the laser displacement sensor system of the present invention;

[0043] Wherein: 1. Base frame base; 2. Support block; 21. Card slot; 22. Insert block; 23. Grooved opening; 24. Screw hole; 3. First U-shaped yoke; 4. Second U-shaped yoke; 5. Amorphous alloy single sheet; 6. Helmholtz excitation coil; 7. Anti-bending fixture; 71. Support frame; 72. Upper cover plate; 73. Lower base; 74. Slide block; 75. Slide groove; 76. Through hole; 8. Low-voltage elastic fixture; 81. Support; 82. Vertical rod; 83. First bolt; 84. Lower clamping piece; 85. Upper clamping piece; 86. Second bolt; 9. Laser displacement sensor system; 91. Slide rail; 92. Laser displacement sensor; 93. L-shaped support rod. Detailed implementation manners

[0044] To facilitate the understanding of this application, the following will provide a more comprehensive description of this application with reference to the relevant attached drawings.

[0045] First of all, the present invention provides a measuring device for the magnetostriction of an amorphous alloy single sheet, including: a measuring system and a fixing device, wherein:

[0046] The fixing device is used to fix the amorphous alloy single sheet 5 to be measured and apply a magnetic field to the amorphous alloy single sheet 5, as Figure 1 shown, including:

[0047] The base frame base 1, which serves as the basis of the entire fixing device, preferably has a plate shape, as Figure 2 shown, and two support blocks 2 are also fixedly arranged on the base frame base 1;

[0048] The yoke, as Figure 3 shown, is formed by docking the first U-shaped yoke 3 and the second U-shaped yoke 4 through their respective U-shaped open ends. The amorphous alloy single sheet 5 to be measured is arranged at the docking position of the first U-shaped yoke 3 and the second U-shaped yoke 4, that is, the two ends of the amorphous alloy single sheet 5 are simultaneously contacted by the U-shaped open ends of the first U-shaped yoke 3 and the second U-shaped yoke 4 to form a closed magnetic circuit;

[0049] Among them, the width of the first U-shaped yoke 3 matches the distance between the two support blocks 2 on the base frame base 1, so that the first U-shaped yoke 3 can be inserted between the two support blocks 2 with its U-shaped open end perpendicular to the base frame base 1 and the two support blocks 2 are used to keep the first U-shaped yoke 3 stable, thereby ensuring the stability of the second U-shaped yoke 4 docked with it and the amorphous alloy single sheet 5 at their docking position.

[0050] The Helmholtz excitation coil 6 is sleeved outside the amorphous alloy single sheet 5 located inside the yoke to provide a uniform magnetic field for the amorphous alloy single sheet 5 to be measured. In the present invention, the yoke and the Helmholtz excitation coil 6 constitute the excitation part of the amorphous alloy single sheet 5;

[0051] Specifically, as Figure 2As shown, clamping grooves 21 capable of clamping the Helmholtz excitation coil 6 are provided on both support blocks 2. That is, the two sides of the Helmholtz excitation coil 6 are clamped by the clamping grooves 21 on the support blocks 2 on both sides of the Helmholtz excitation coil 6, so that it is stably sleeved outside the amorphous alloy single sheet 5 located inside the yoke.

[0052] In the present invention, the excitation part of the amorphous alloy single sheet 5 is composed of a yoke and a Helmholtz excitation coil 6.

[0053] The anti-bending fixture 7 has a cavity inside that matches the shape of the amorphous alloy single sheet 5, and openings are provided at both ends of the cavity, so that the anti-bending fixture 7 can be sleeved on the amorphous alloy single sheet 5 located inside the yoke to prevent the amorphous alloy single sheet 5 from deforming under the action of a magnetic field.

[0054] Furthermore, a through hole 76 is opened at the top of the anti-bending fixture 7 to reserve a position for pasting a triaxial strain gauge on the amorphous alloy single sheet 5, that is, the amorphous alloy single sheet 5 can be prevented from bending without affecting the measurement. A support frame 71 capable of supporting on the base frame base 1 is provided at the bottom of the anti-bending fixture 7, and the support frame 71 cooperates with the slotted opening 23 opened on the base frame base 1 to support the entire anti-bending fixture 7.

[0055] In this embodiment, as Figure 4 shown, the anti-bending fixture 7 preferably adopts a detachable structure, including: an upper cover plate 72 and a lower base 73 slidably connected thereto. Among them, sliders 74 are fixedly provided on both sides of the upper cover plate 72, and sliding grooves 75 matching the sliders 74 are correspondingly provided on both sides of the lower base 73. That is, the upper cover plate 72 and the lower base 73 are fixed through the sliding cooperation of the sliders 74 and the sliding grooves 75. At the same time, a through hole 76 is opened on the upper cover plate 72, and a support frame 71 is fixedly provided at the bottom of the lower base 73.

[0056] In addition, in this embodiment, the material of the anti-bending fixture 7 is preferably polyether ether ketone. Polyether ether ketone has the characteristics of self-lubrication and low friction coefficient. The characteristics of the polyether ether ketone material itself can reduce the influence of the anti-bending fixture 7 on the magnetostrictive characteristics of the amorphous alloy single sheet 5 to be measured; polyether ether ketone also has excellent electrical properties, it has good electrical insulation properties, is suitable for use in the electrical and electronic fields, and can still maintain stable electrical properties under high voltage and high frequency conditions; polyether ether ketone has high fatigue resistance, is suitable for long-term use, and its melting point is relatively high, and the electromagnetic heat generated during the measurement will not affect its material properties.

[0057] The low-voltage elastic fixture 8 is fixedly provided on the base frame base 1 and is located at both ends of the first U-shaped yoke 3, and is used for clamping both ends of the amorphous alloy single sheet 5, as Figure 5As shown in the figure, it includes: a support 81 fixedly connected to the screw hole 24 on the base frame 1 by bolts, a vertical rod 82 fixedly arranged on the support 81, a lower clamping piece 84 fixedly connected to the vertical rod 82 by a plurality of first bolts 83, an upper clamping piece 85 slidably sleeved on the vertical rod 82 above the lower clamping piece 84, threaded holes corresponding to each other on the upper clamping piece 85 and the lower clamping piece 84, and the upper clamping piece 85 and the lower clamping piece 84 are connected by a second bolt 86;

[0058] In this embodiment, when the low-voltage elastic fixture 8 is specifically used, the position of the lower clamping piece 84 on the vertical rod 82 can be adjusted by screwing the first bolt 83 to ensure that its contact surfaces with the first U-shaped yoke 3 and the amorphous alloy single sheet 5 are on a horizontal plane. Then, after the upper clamping piece 85 is slid to the proper position on the vertical rod 82, the pre-tightening force on the end of the amorphous alloy single sheet 5 by the upper clamping piece 85 and the lower clamping piece 84 is realized by screwing the second bolt 86. After clamping at both ends, local stress concentration of the amorphous alloy single sheet 5 to be measured can be avoided;

[0059] Furthermore, the materials of the upper clamping piece 85 and the lower clamping piece 84 are preferably silicone, so as to avoid scratches or indentations on the amorphous alloy single sheet 5 caused by traditional metal materials during clamping, protect the surface integrity of the amorphous alloy single sheet 5 to be measured, and ensure that subsequent tests are not affected.

[0060] In other embodiments, the present invention can also be provided with a laser displacement sensor system 9 for detecting the flatness of the amorphous alloy single sheet 5 on the two support blocks 2, as Figure 6 shown, it includes: a slide rail 91 and a laser displacement sensor 92 slidably arranged on the slide rail 91, wherein the slide rail 91 is located above the amorphous alloy single sheet 5 and is parallel. Both ends of the slide rail 91 are fixedly connected with L-shaped support rods 93. An insertion socket is provided at the bottom end of the L-shaped support rod 93 and is inserted into the insertion block 22 provided on the support block 2. That is, the slide rail 91 is arranged parallel to the amorphous alloy single sheet 5 by inserting the L-shaped support rod 93 into the support block 2. The flatness of the amorphous alloy single sheet 5 is detected by sliding the laser displacement sensor 92 on the slide rail 91. The laser displacement sensor 92 can select a laser sensor with the model PEMKELC-S030MN, and its measurement accuracy is 10μm, which can accurately measure the flatness difference of the sample sheet.

[0061] Furthermore, the material of the slide rail 91 is preferably polyether ether ketone, that is, the self-lubricity and fatigue resistance of polyether ether ketone are utilized to facilitate the long-term sliding of the laser displacement sensor 92 on the slide rail 91.

[0062] When the fixing device provided by the present invention fixes the amorphous alloy single sheet 5 to be measured, the second U-shaped yoke 4 needs to be picked up first, and the processed amorphous alloy single sheet 5 to be measured is passed through the lower base 73 of the Helmholtz excitation coil 6 and the anti-bending fixture 7. The two ends of the amorphous alloy single sheet 5 are clamped by the low-pressure elastic fixtures 7 located at both ends of the first U-shaped yoke 3. The upper cover plate 72 of the anti-bending fixture 7 is slidably connected to the lower base 73 and fixed stably. Then, a laser displacement sensor 92 is used to measure the displacement of the point to be measured to calibrate the straightness. After ensuring no bending in the initial state by adjusting the clamping force of the low-pressure elastic fixture 8, the second U-shaped yoke 4 is put back, and then the laser displacement sensor system 9 is disassembled to complete the fixing of the amorphous alloy single sheet 5 to be measured.

[0063] The measuring system uses the three-axis strain gauge method to measure the magnetostrictive characteristics of the amorphous alloy single sheet 5 under a magnetic field, including: three-axis strain gauges, strain bridge boxes, strain amplifiers, BNC adapters, data acquisition cards, and computers. Among them:

[0064] The three-axis strain gauges are pasted on the amorphous alloy single sheet 5 to convert the deformation signal of the amorphous alloy single sheet 5 under a magnetic field into a resistance change signal;

[0065] The strain bridge box is used to convert the resistance change signal of the three-axis strain gauges into a voltage change signal;

[0066] The strain amplifier is used to amplify the voltage change signal;

[0067] The BNC adapter is used to convert the amplified voltage change signal into a digital signal;

[0068] The data acquisition card is used to transmit the digital signal into the computer;

[0069] The computer uses the LabVIEW control program to realize the measurement and processing of the digital signal.

[0070] Secondly, the present invention uses the above-mentioned measuring device to measure the magnetostriction of the amorphous alloy single sheet. The usage method of the measurement includes the following steps:

[0071] Step 1: Pretreat the amorphous alloy single sheet 5 to be measured;

[0072] Prepare the amorphous alloy single sheet 5 to be tested, ensure that its surface is flat and free of defects, and cut it to a suitable size according to the size of the iron yoke and the anti-bending clamp 7 in the fixing device, that is, the length of the amorphous alloy single sheet 5 is long enough to be clamped by the low-pressure elastic silicone clamp, and the width is consistent with the width of the iron yoke. Spray a degreasing liquid such as acetone on the amorphous alloy single sheet 5, wipe the measuring area clean with a cotton swab, apply a special adhesive for strain gauges on the measuring area, and then quickly stick the triaxial strain gauge to the test area, and keep the horizontal angles of the triaxial strain gauge and the amorphous alloy single sheet 5 at 0°, 45°, and 90° respectively. Let it stand for about 1 minute, and use finger force to press the adhesive between the triaxial strain gauge and the amorphous alloy single sheet 5. In this way, a layer of adhesive film can be formed between the amorphous alloy single sheet 5 and the triaxial strain gauge, and the pressure should be maintained for about 2 minutes;

[0073] Step 2: Assembling the amorphous alloy single piece 5 onto a fixing device;

[0074] First, remove the second U-shaped iron yoke 4, pass the lower base 73 of the anti-bending fixture 7 through the Helmholtz excitation coil 6 and fix it on the base frame 1, then pass the amorphous alloy single sheet 5 to be tested with the triaxial strain gauge pasted through the Helmholtz excitation coil 6 and place it flat on the lower base 73 of the anti-bending fixture 7;

[0075] Secondly, the low-pressure elastic clamps 8 at both ends of the first U-shaped iron yoke 3 are fixedly installed on the base frame 1 to ensure that they are firmly fixed and will not shake left and right to cause measurement errors. By adjusting the tightness of the second bolt 86 between the upper clamp 85 and the lower clamp 84, a pre-tightening force is applied to the amorphous alloy single sheet 5 to be measured, and then the anti-bending clamp 7 is used to ensure that the sample remains horizontal and flat without bending;

[0076] Next: Install two laser displacement sensor systems 9 on the support block 2 of the base frame 1, and align the plug block 22 on the upper surface of the support block 2 with the socket at the bottom end of the L-shaped support rod 93 of the laser displacement sensor system 9 to install it firmly. The upper cover plate 72 has a square through hole 76 reserved. Use two laser displacement sensors 92 to measure the four test points of the amorphous alloy single piece 5 at the exposed through hole 76, and compare the data of the two laser displacement sensors 92 to verify the flatness of the amorphous alloy single piece 5.

[0077] It should be noted that if the difference in the data measured by the two laser displacement sensors 92 in the length direction is less than 0.1mm, it means that the amorphous alloy single sheet 5 has no bending in the initial state and the experiment can continue; if bending occurs in the initial state, it is necessary to adjust the preload force of the low-pressure elastic clamps 8 on both sides and then measure the straightness of the amorphous alloy single sheet 5 until the data difference is less than 0.1mm before proceeding to the subsequent steps.

[0078] Finally: After confirming that there is no initial bending in the single amorphous alloy sheet 5, the laser displacement sensor system 9 can be removed and put back into the second U-shaped yoke 4. Then, connect the three-axis strain gauge with the strain bridge box and the strain amplifier. When the single amorphous alloy sheet 5 is magnetized, it will generate a tiny geometric deformation. The strain gauge converts the deformation signal into a resistance change, and through the strain bridge box, it is converted into a voltage signal. After being amplified by the strain amplifier, it is then converted into a corresponding strain signal and transmitted into the LabVIEW control program in the computer through the BNC adapter and the data acquisition card to realize the measurement and processing of the signal.

[0079] It should be noted that during the measurement process, 3 channels of magnetostrictive signals need to be collected. Therefore, a high-performance data acquisition card should be selected. Strain gauges with larger sizes should be chosen to reflect the average magnetostriction value of the sample sheet. The strain amplifier should have the functions of filtering and amplifying signals. Therefore, for the hardware of measuring magnetic flux, the PXIe-6368 data acquisition board produced by NI company is selected respectively. The three-axis strain gauge, the strain bridge box and the strain amplifier select the KFG-10-120-D17-11 type strain gauge, the DB-120A type strain bridge box and the DPM-911B type strain amplifier produced by KYOWA company;

[0080] Step 3: Start the test;

[0081] Set the excitation frequency to the power frequency of 50 Hz to study the magnetostriction characteristics of the amorphous alloy at the power frequency. During the measurement process, since the saturation magnetic flux density of the single amorphous alloy sheet 5 is about 1.5 T, the peak magnetic flux density B max gradually increases from 0.5 T to 1.5 T with a step size of 0.1 T. To reduce the measurement error, the strain signal measurement process is repeated 5 times and the average value is taken. According to the obtained data, a magnetostriction curve is plotted to analyze the magnetostriction characteristics of the amorphous alloy.

[0082] It should be understood that those skilled in the art, inspired by the technical concept of the present invention and without departing from the content of the present invention, can also make various improvements or transformations based on the above content, and this still falls within the protection scope of the present invention.

Claims

1. A magnetostriction measuring device for an amorphous alloy single sheet, comprising: a fixing device for fixing the amorphous alloy single sheet (5) and applying a magnetic field to the amorphous alloy single sheet (5); and a measuring system for measuring the magnetostriction characteristics of the amorphous alloy single sheet (5) under a magnetic field by using a triaxial strain gauge method, wherein the fixing device comprises: A base frame (1) and two support blocks (2) fixedly arranged on the base frame base (1), an iron yoke inserted between the two support blocks (2), the iron yoke comprising a first U-shaped iron yoke (3) and a second U-shaped iron yoke (4) butted against the U-shaped opening end of the first U-shaped iron yoke (3), an amorphous alloy single sheet (5) being arranged at the butt joint between the first U-shaped iron yoke (3) and the second U-shaped iron yoke (4), a Helmholtz excitation coil (6) being sleeved on the outside of the amorphous alloy single sheet (5) located inside the iron yoke, and the Helmholtz excitation coil (6) being supported on the two support blocks (2); The invention is characterized in that an anti-bending fixture (7) is sleeved on the outside of the amorphous alloy single piece (5) located inside the iron yoke, a through hole (76) is provided on the top of the anti-bending fixture (7), and a support frame (71) supported on the base frame (1) is provided on the bottom of the anti-bending fixture (7); Two ends of the amorphous alloy single piece (5) located outside the iron yoke are provided with low-pressure elastic clamps (8) fixedly arranged on the base frame (1) and used for clamping the two ends of the amorphous alloy single piece (5).

2. The magnetostriction measuring device for an amorphous alloy single sheet according to claim 1, characterized in that: The anti-bending clamp (7) comprises: an upper cover plate (72) and a lower base (73) slidably connected to the upper cover plate (72); sliders (74) are fixedly arranged on both sides of the upper cover plate (72); sliding grooves (75) matching the sliders (74) are correspondingly arranged on both sides of the lower base (73); a through hole (76) is provided on the upper cover plate (72); and a support frame (71) is fixedly arranged at the bottom of the lower base (73).

3. The magnetostriction measuring device for an amorphous alloy single sheet according to claim 2, characterized in that: The material of the anti-bending clamp (7) is polyetheretherketone.

4. The magnetostriction measuring device for an amorphous alloy single sheet according to claim 1, characterized in that: The low-pressure elastic clamp comprises a support (81) fixedly connected to a base frame (1) by bolts, a vertical pole (82) is fixedly arranged on the support (81), a lower clamp (84) is fixedly connected to the vertical pole (82) by a plurality of first bolts (83), an upper clamp (85) slidably sleeved on the vertical pole (82) is arranged above the lower clamp (84), threaded holes are correspondingly arranged on the upper clamp (85) and the lower clamp (84), and the threaded holes connect the upper clamp (85) and the lower clamp (84) by cooperating with second bolts (86).

5. The magnetostriction measuring device for an amorphous alloy single sheet according to claim 4, characterized in that: The upper layer clip (85) and the lower layer clip (84) are made of silica gel.

6. The magnetostriction measuring device for an amorphous alloy single sheet according to claim 1, characterized in that: A laser displacement sensor system (9) for detecting the flatness of an amorphous alloy single sheet (5) is detachably arranged on the two support blocks (2).

7. The magnetostriction measuring device for an amorphous alloy single sheet according to claim 6, characterized in that: The laser displacement sensor system (9) comprises: a slide rail (91) and a laser displacement sensor (92) slidably arranged on the slide rail (91); the slide rail (91) is located above and parallel to the amorphous alloy single sheet (5); both ends of the slide rail (91) are fixedly connected to an L-shaped support rod (93); the bottom end of the L-shaped support rod (93) is provided with a socket and is plugged into an insert block (22) arranged on the support block (2).

8. The magnetostriction measuring device for an amorphous alloy single sheet according to claim 7, characterized in that: The material of the slide rail (91) is polyetheretherketone.

9. The magnetostriction measuring device for an amorphous alloy single sheet according to claim 1, characterized in that: The measuring system comprises: a triaxial strain gauge, a strain bridge box, a strain amplifier, a BNC adapter, a data acquisition card and a computer, wherein: The triaxial strain gauge is pasted on the amorphous alloy single sheet (5) and is used to convert the deformation signal of the amorphous alloy single sheet (5) under the magnetic field into a resistance change signal; The strain bridge box is used to convert the resistance change signal of the triaxial strain gauge into a voltage change signal; The strain amplifier is used to amplify the voltage change signal; The BNC adapter is used to convert the amplified voltage change signal into a digital signal; The data acquisition card is used to transmit the digital signal to the computer; The computer uses LabVIEW control program to measure and process digital signals.

10. A method for using the magnetostriction measuring device for an amorphous alloy single sheet according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: pre-treating the amorphous alloy single chip (5) to be tested; Prepare the amorphous alloy single sheet (5) to be tested, ensure that its surface is flat and free of defects, cut it to a length of the amorphous alloy single sheet (5) sufficient to be clamped by the low-pressure elastic clamp (8) according to the size of the iron yoke and the anti-bending clamp (7) in the fixing device, and the width is consistent with the width of the iron yoke, spray degreasing liquid on the amorphous alloy single sheet (5), wipe the measuring area with a cotton swab, apply a strain gauge adhesive on the measuring area, and then stick the triaxial strain gauge to the test area, and keep the angles between the triaxial strain gauge and the amorphous alloy single sheet (5) in the horizontal direction at 0°, 45°, and 90° respectively, let it stand for about 1 minute, use finger force to press the adhesive between the triaxial strain gauge and the amorphous alloy single sheet (5), and maintain the pressure for 2 minutes; Step 2: Assembling the amorphous alloy single piece (5) onto a fixing device; First, remove the second U-shaped iron yoke (4), pass the lower base (73) of the anti-bending fixture (7) through the Helmholtz excitation coil (6) and fix it on the base of the base frame (1), and then pass the amorphous alloy single piece (5) to be tested with the triaxial strain gauge pasted through the Helmholtz excitation coil (6) and place it flat on the lower base (73) of the anti-bending fixture (7); Secondly, the low-pressure elastic clamps (8) at both ends of the first U-shaped iron yoke (3) are fixedly mounted on the base frame (1) to ensure that they are firmly fixed, and a pre-tightening force is applied to the amorphous alloy single sheet (5) to be tested by adjusting the tightness of the second bolt (86) between the upper clamp (85) and the lower clamp (84), and then the anti-bending clamp (7) is used to ensure that the amorphous alloy single sheet (5) remains horizontal and flat without bending; Next, two laser displacement sensor systems (9) are installed on the support block (2) of the base frame (1), and the plug block (22) on the upper surface of the support block (2) is connected to the socket at the bottom end of the L-shaped support rod (93) of the laser displacement sensor system (9) to ensure a secure installation. The through hole (76) reserved on the upper cover plate (72) is used to respectively measure four test points of the amorphous alloy single chip (5) at the exposed through hole (76) in conjunction with the laser displacement sensor (92), and the data of the two laser displacement sensors (92) are compared to verify the straightness of the amorphous alloy single chip (5); Step 3: Start testing; The excitation frequency is set to 50 Hz to study the magnetostrictive properties of the amorphous alloy under the industrial frequency. During the measurement, since the saturation magnetic flux density of the amorphous alloy single piece (5) is about 1.5 T, the peak value of the magnetic flux density B max The strain signal is gradually increased from 0.5 T to 1.5 T with a step length of 0.1 T. The strain signal measurement process is repeated 5 times and averaged. A magnetostriction curve is drawn based on the obtained data to analyze the magnetostriction characteristics of the amorphous alloy single piece (5).

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